Campylobacter, one of the four key causes of diarrheal diseases of humans, is a zoonotic bacteria... more Campylobacter, one of the four key causes of diarrheal diseases of humans, is a zoonotic bacterial pathogen commonly found in cattle, sheep, goats and poultry. As the number of crossbred cattle steadily increases in Bangladesh through intensified livestock production to fulfill the demand of animal-source protein, the risk of pathogenic Campylobacter transmission is likely to increase in humans and animals including the farm environment. The objective of this study was to confirm the risk pathways and estimate the likelihood of entry and exposure risks of Campylobacter for cattle in the farm holdings. Following OIE risk analysis guidelines and tools, we assessed the risk level of each pathway using secondary and field observation data used in expert opinion elicitation process to formulate and confirm the risk level and their combined risk. The probable risk nodes were combined to obtain the total risk level for each specific transmission pathway using the template adapted by Zepeda-Sein based upon expert opinions. The evaluations revealed that the risk of the entry and exposure of Campylobacter is medium with medium levels of uncertainty. Moreover, the consequence pathways showed high risk with low level of uncertainty. Finally, the overall risk for transmission was evaluated as medium with medium level of uncertainty. This study suggests that there is a significant risk of Campylobacter transmission which may spread in humans, animals and successfully maintain in the farm environments. Good animal husbandry practices along with personal hygiene and sanitation practices of animal attendants including their family members are needed to minimize the risk of Campylobacter transmission from farmed cattle to humans. The findings of this study could be useful for framing functional risk reduction measures at the low-resource settings using One Health approach considering human, animal and environmental health perspectives.
Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, ... more Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, especially in developing nations, where it presents considerable public health concerns. This study was conducted to examine the virulence gene profiles and antibiotic resistance patterns of E. coli strains isolated from piper betel leaves. A total of 100 betel leaf samples, including fresh (n = 60) and ready-to-eat (n = 40) specimens, were collected and tested for the presence of E. coli using standard diagnostic techniques, such as selective culture methods, staining, latex agglutination, and polymerase chain reaction (PCR) assays. Further, the identified E. coli isolates underwent PCR-based testing for virulence genes and disk diffusion assays to assess antibiotic susceptibility. Among the 100 samples screened, 4% (n = 4/100; 95% CI: 1.57–9.84; P = 0.1126) were identified as E. coli O157, and 33% (n = 33/100; 95% CI: 24.56–42.69; P = 0.4011) were classified as non-O157 isolates. The virulence gene stx1 was found in 10.81% of isolates, while stx2, eaeA, and hlyA genes were not detected in any samples. Antibiotic resistance analysis showed that all isolates (100%, 37/37) were resistant to amoxicillin and erythromycin, with 75.68% (28/37) demonstrating resistance to tetracycline. Notably, all isolates were fully susceptible to ceftriaxone and ciprofloxacin. A majority (72.97%, 27/37) of isolates were sensitive to streptomycin, and 67.57% (25/37) were sensitive to gentamicin. Additionally, 86.48% of the E. coli isolates exhibited multidrug resistance (MDR), showing 10 resistance patterns, including 8 MDR patterns. The most common MDR pattern was AMX-TE-E, observed in 56.76% (21/37) of isolates. One isolate demonstrated resistance to six of the eight tested antibiotics across four distinct classes, with the resistance pattern AMX-TE-GEN-S-E-AZM. The MAR indices for E. coli isolates ranged between 0.25 and 0.75. These findings highlight the significant threat posed to global public health by multidrug-resistant shiga toxin-producing E. coli found on piper betel leaves in urban environments.
We aimed to estimate the overall apparent prevalence, true prevalence, and the spatial, temporal,... more We aimed to estimate the overall apparent prevalence, true prevalence, and the spatial, temporal, and test-specific burden of bovine tuberculosis in Bangladesh. PubMed, Web of Science, Scopus, Google Scholar, and BanglaJOL were searched for bovine tuberculosis publications in Bangladesh from 1 January 1970 to 23 June 2023. Of 142 articles screened, systematic review and meta-analysis were performed on 22 (15.5%) articles. The apparent estimated bovine tuberculosis prevalence was 7%. The apparent Bayesian pooled mean bovine tuberculosis prevalences based on caudal fold test and single intradermal comparative tuberculin test were 7.83% and 9.89%, respectively, and the true pooled mean prevalences were 10.39% and 10.48%, respectively. Targeted interventions are recommended for districts with higher prevalence to effectively reduce the bovine tuberculosis burden in those areas. Current diagnostic practices employed in Bangladesh may not accurately reflect the bovine tuberculosis burden. Our findings highlight the need for better diagnostic tools and supplemental testing methods to ensure accurate diagnosis and surveillance. Efforts should prioritize obtaining 'true' prevalence estimates corrected for misclassification bias, rather than relying solely on apparent prevalence. Underestimating the bovine tuberculosis burden could result in inadequate resource allocation and hinder the implementation of effective control measures.
Objectives:
Citrobacter freundii is a prevalent source of nosocomial infections and a well-known ... more Objectives: Citrobacter freundii is a prevalent source of nosocomial infections and a well-known cause of diarrheal diseases. In recent years, it has also become increasingly resistant to various antimicrobials. In this study, we screened and characterized a multidrug-resistant (MDR) C. freundii isolate obtained from a domesticated diseased duck to better understand the genetic features, molecular epidemiology, and underlying factors linked to the antimicrobial resistance genes (ARGs) and virulence factor genes (VFGs) of the isolate.
Methods: The C. freundii BAU_TM8 strain was isolated using culturing, staining, biochemical, polymerase chain reaction, and Matrix-assisted laser desorption/ionization-time of flight methods. The MDR properties of the strain were determined by a disk diffusion test. The genomic sequence of C. freundii BAU_TM8 was performed using the Illumina NextSeq2000 platform. The ARGs, VFGs, and genomic functional characteristics of the C. freundii BAU_TM8 strain were identified using several open-source databases.
Results: The sequence type of this strain was ST669, and the pathogenicity index of the strain was 0.919. Moreover, the strain had an estimated genome length of 5,797,806 bp, harboring 62 contigs, a G + C content of 54.32 %, and five contig L50s with an N50 value of 443,947 bp. Using phylogenetic analysis, this strain was closely related to two strains isolated from human and environmental samples in the USA and China despite huge geographical distances. The C. freundii BAU_TM8 strain consisted of 40 AGRs encoding resistance to 19 antimicrobial categories, e.g., fluoroquinolones, macrolides, folate pathway antagonists, aminoglycosides, tetracyclines, cephalosporins, and others. According to the phenotypic assay and genome sequence, the sensitivity and specificity of resistance profiles of the strain were 100 % and 20 %, respectively. Moreover, the virulence factor database detected 66 VFGs in this strain. This strain contained 1581 subsystems, having 33 % subsystem coverage and 2275 genes encoding amino acid derivatives, carbohydrate metabolism, protein metabolism, cofactors, vitamins, prosthetic groups, pigments, respiration, motility and chemotaxis, stress response, DNA metabolism, nucleosides and nucleotides, and others.
Conclusions: To the best of our knowledge, this is the first WGS report of C. freundii from a domesticated duck in Bangladesh. The ubiquitous occurrence of ARGs and VFGs in the C. freundii BAU_TM8 strain detected in this study highlights the growing concern about antimicrobial resistance in humans, animals, and environments.
In Bangladesh, little is known about the role of climatic factors influencing spatio-temporal occ... more In Bangladesh, little is known about the role of climatic factors influencing spatio-temporal occurrence among different food grains of aflatoxins, which have been linked to liver cancer cases and other health hazards. In this study, 252 food grain samples of 10 types were collected from retail markets at 18 districts, pre-monsoon, monsoon and post-monsoon seasons during February-September, 2018. Occurrence and concentration of total aflatoxins in the samples were analysed by a direct competitive enzyme-linked immunosorbent assay, and compared with climatic data (temperature, humidity, rainfall, and sunshine hours). Contamination of aflatoxins was found in approx. 38% (n=96) of the total samples, with highest occurrence in groundnuts (82%), followed by corn grains (70%), chick pea (54.5%), wheat grain (50%) and green gram (42.9%). Aflatoxins occurrence was moderate in split chick pea (30.8%), yellow pea (28.2%), black gram (27.8%), and lentils (27.6%), while the lowest in grass pea (17.6%). Aflatoxins concentration was found to exceed the European Union permissible limit (≤5 µg kg-1) in 33 (13.1%) samples. Overall, approximately 5.6%, 7.5%, and 25.0% samples were contaminated with high (10-19 ppb), medium (5-9 ppb) and low (1-4 ppb) concentrations of aflatoxins, respectively. High level concentration of aflatoxins was more frequent in groundnut (36%) and wheat grain (20%), in comparison to other types. Occurrence of aflatoxins during premonsoon was detected among 21% (19/91) samples, which increased to ca. 30% (36/119) during monsoon, and 98% (41/42) during post-monsoon. However, aflatoxins mean concentration during post-monsoon was comparatively low than the other seasons. Variations in aflatoxins monthly prevalence correlated significantly with relative humidity (p ≤ 0.01) and rainfall (p≤ 0.05), when a 1-month time lag was considered. Therefore, predisposing climatic conditions, i.e., rainfall incidences and persistence of higher relative humidity in the previous month(s), have salient influence on aflatoxins occurrence, potentially impacting both pre-harvest and stored food grains. This study underscores the need of a more holistic monitoring of aflatoxins in agricultural products for a longer term, and adoption of proper intervention measures for food grains while being stored and before consumption.
In the intricate tapestry of human existence, few threads are as fundamental and indispensable as... more In the intricate tapestry of human existence, few threads are as fundamental and indispensable as food (Morawicki and Díaz González, 2018). It sustains us, fuels our endeavors, and serves as a cornerstone of culture and society (Fardet and Rock, 2020). Yet, amidst the abundance and variety, lurks a silent menacethe specter of unsafe and insecure food (Tariqujjaman et al., 2023). This editorial endeavors to shed light on the critical importance of food safety and security, emphasizing the pivotal role of the Asian-Australasian Journal of Food Safety and Security (AAJFSS) in advancing knowledge and safeguarding public health in this domain. At the core of AAJFSS's mission lies a commitment to fostering rigorous scientific inquiry into all facets of food safety and security (
As we navigate the complexities of the modern world, the pursuit of scientific understanding in m... more As we navigate the complexities of the modern world, the pursuit of scientific understanding in medical and biological research becomes increasingly vital (Betz et al., 2023). The Asian Journal of Medical and Biological Research (AJMBR) stands as a beacon in this pursuit, dedicated to the dissemination of high-quality and innovative research spanning a vast array of disciplines (
Background and Aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ile... more Background and Aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ileitis, infertility, and abortion. Thus, this study aimed to estimate the prevalence of Campylobacter spp. in farming sheep and to detect risk factors, molecular patterns, and antimicrobial susceptibility status of these pathogens. Materials and Methods: Four hundred and eight fecal samples were collected from 12 flocks in the Mymensingh and Sherpur districts. Samples were tested by both basic (culture and biochemical tests) and molecular (initially 16S rRNA and later hipO gene-based polymerase chain reaction). Furthermore, the antimicrobial susceptibility status of Campylobacter jejuni was confirmed using disk diffusion. Flock-and animal-level data were captured using semi-structured interviews with farm owners under bivariate and multivariate logistic regression analyses to confirm the risk factors for Campylobacterpositive status. Results: The prevalence of C. jejuni staining at the animal and flock levels was 8.82% (36/408) and 66.70% (8/12), respectively. The age of sheep was identified as an important risk factor. Up to 1 year of age, sheep were 3.78 times more likely to be infected with C. jejuni (95% confidence interval: 1.0736-13.3146, p = 0.038). Of the 36 isolates of C. jejuni, all were found to be fully susceptible (100%) to gentamicin and ciprofloxacin. In this study, three antimicrobial agents, oxytetracycline, azithromycin, and ceftriaxone, were fully resistant (100%). The majority of isolates were resistant to a combination of 4-6 antimicrobial agents. Conclusion: The present study highlights the predominant maintenance of zoonotic Campylobacter species in sheep, and their burden on human health is enormous. Therefore, environmental, animal, and human health needs to be focused under a One Health lens to mitigate the occurrence of Campylobacter in farm settings and to prevent further introduction to animals and humans.
We announce the genome sequence of the Citrobacter portucalensis BAU_133-2 strain isolated from a... more We announce the genome sequence of the Citrobacter portucalensis BAU_133-2 strain isolated from a domestic duck. Our assembled genome contained a length of 4.8 Mb, 110.0× genome coverage, 51.91% of an average GC content, 1 plasmid, 1 CRISPR array, 8 prophages, 27 antibiotic resistance genes, and 75 virulence factor genes.
Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused b... more Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused by Mycobacterium bovis. This study aimed to evaluate the efficacy of the interferon-gamma (IFN-γ) assay and single-intradermal comparative tuberculin test (SICTT) in detecting bTB. Materials and Methods: In an earlier study, 150 positive, 83 inconclusive, and 480 negative animals from 24 cattle herds were screened using SICTT. From these groups, 125 positive, 17 inconclusive, and six negative animals were subsequently verified using the IFN-γ assay. Single-intradermal comparative tuberculin test outcomes were interpreted according to standard guidelines, whereas blood samples were collected and stimulated with purified protein derivatives. Sandwich enzyme-linked immunosorbent assay was used to measure secreted IFN-γ. Concordant and Bayesian latent class analyses were performed to evaluate test performance. Results: Results from the IFN-γ assay revealed that 83.2%, 64.7%, and 16.67% of the animals were positive in the SICTTpositive, inconclusive, and negative animal categories, respectively. Sensitivity (SE) and specificity (SP) of SICTT were 83.9% (95% confidence interval [CI]: 77.4-90.1) and 95.7% (95% CI: 86.9-99.7), respectively. Sensitivity and SP for the IFN-γ assay were 78.9% (95% CI: 71.9-85.4) and 83.9% (65.9-95.9), respectively. The use of both tests in parallel increases the SE of bTB detection (~94%), compared with SICTT alone. Conclusion: Use of the IFN-γ assay with SICTT in parallel, predominantly on cattle demonstrating an inconclusive SICTT outcome, boosts bTB detection rate in low resource settings.
We sequenced a multidrug-resistant strain of Citrobacter freundii, 132-2, isolated from a cloacal... more We sequenced a multidrug-resistant strain of Citrobacter freundii, 132-2, isolated from a cloacal swab sample of a domestic duck. The whole genome of the C. freundii 132-2 strain had a length of 5,097,592 bp, 62 contigs, two plasmids, and an average G1C content of 51.85%, with a 105.0Â genome coverage.
Bovine tuberculosis (bTB) is considered to be an endemic disease having zoonotic importance in Ba... more Bovine tuberculosis (bTB) is considered to be an endemic disease having zoonotic importance in Bangladesh, but no economic analysis describing the burden of this disease has been reported so far. The objective of this study was to calculate the economic losses of bTB in crossbred farming cattle focused mainly on livestock production loss including decreased milk and meat production, neonatal deaths, infertility and other associated losses in two selected cattle-dense districts of Bangladesh. Utilizing the data from a cross-sectional survey on bTB prevalence conducted in 2019 combined with field interview data collection on different financial parameters on livestock goods and published secondary data, estimation of economic loss for a single year in two studied district (Dhaka and Mymensingh) of Bangladesh was done. The study confirmed an annual estimated economic loss due to bTB in farming cattle was BDT 1347.72 million (95% CI = 997.43-1801.65), equivalent to US$ 16.04 million (95% CI= 11.87-21.45). The study showed that the highest economic loss was due to decreased milk production (BDT 697.25 million) followed by decreased meat production (BDT 531.22 million), other pertinent losses (vet health care, cleaning and disinfection costs, and restocking costs, if required), infertility and neonatal deaths. Due to a high animal-level prevalence of bTB in Dhaka, the study confirmed a higher economic loss in this district (BDT 717.80 million, 95% CI= 617.61-819.72) than that in Mymensingh (BDT 629. 92 million, 95% CI= 379.82-981.93). The study provides an in-depth insight into the impact of bTB on livestock productivity in two cattle rearing districts of Bangladesh. The model developed through this study could be applied to the estimation of the overall bTB burden in Bangladesh.
This study aimed to investigate Campylobacter jejuni, a major cause of food-borne bacterial infec... more This study aimed to investigate Campylobacter jejuni, a major cause of food-borne bacterial infections worldwide, in fresh vegetables from five upzillas (Mymensingh, Trishal, Bhaluka, Muktagacha, and Fulbaria) in the Mymensingh district between July 2020 and April 2023. Using cultural, biochemical, and molecular techniques, 100 fresh vegetable samples (including tomato, carrot, cucumber, green chili, and coriander) were examined for C. jejuni. The isolates were further tested for virulence genes and antimicrobial susceptibility. Out of the 100 samples, 23% were confirmed as C. jejuni, by 16S rRNA gene-based polymerase chain reaction and all were found to be virulent with cytolethal distending toxins (cdtA, cdtB and cdtC genes). Antibiotic susceptibility testing revealed resistance to amoxicillin (47.83%), tetracycline (43.48%), and streptomycin (39.13%) among the isolates. However, ceftriaxone and ciprofloxacin were effective against 47.83% and 43.48% of the isolates, respectively. Moreover, 52.17% of the isolates were sensitive to erythromycin. Alarmingly, 34.78% of the C. jejuni isolates exhibited multidrug resistance (MDR) with eight different antibiotic resistance patterns, including four MDR patterns. These findings highlight the presence of virulent and antibiotic-resistant C. jejuni in fresh vegetables, emphasizing the need for monitoring and control to ensure food safety and public health issues.
Fungal endophyte is a fungal that lives in plant organism as mutualism association. The role of f... more Fungal endophyte is a fungal that lives in plant organism as mutualism association. The role of fungal endophyte is a growth promoter or/and microbial pathogen inhibitor. This study investigated antifungal activity of Colletotrichum truncatum E10, an endophytic fungus derived from Musa acuminata (AAA group), against 7 isolates of Aspergillus obtained from lower respiratory samples of COVID-19 patients. In addition, IAA production of this strain was also observed. All isolates of Aspergillus were identified using MALDI-TOF MS. The fungal endophyte, C. truncatum E10, was screened for IAA induction with and without 0.1, 2 and 8 mg/mL of L-tryptophan based on colorimetric method using Salkowski reagent which produced pinkish to reddish solution indicating the presence of IAA. Antagonist activity was based on dual culture assay measured in colony growth inhibition (CGI). C. truncatum E10 produced the highest IAA concentration of 112.81±0.12 µg/mL when 8 mg/mL of L-tryptophan added. The strong antagonist activities were shown by C. truncatum E10 against 5 Aspergillus isolates including 2 A. fumigatus: sp442/6 (CGI=57.835.11%) and sp269/11 (CGI=53.018.52%), 1 A. niger sp26/7 (CGI=57.8315.33%) and 2 A. flavus: sp26/7 (CGI=56.6313.63%) and sp36/7 (CGI=57.230.85%), whereas the colony growth inhibition (CGI) of other 2 isolates including A. fumigatus sp567/6 and A. flavus sp269/11 were less than 50%. In this study, C. truncatum E10 produced substances that inhibited human fungal pathogen including A. fumigatus, A. flavus and A. niger. Moreover, it can produce IAA activity. Further investigations are being conducted to expand the plant growth promotion effects and determine IAA biosynthesis pathway. For antifungal activity, the bioactive metabolites produced by this endophytic fungal isolate should be characterized to specify the effective compounds.
Campylobacter is a prevalent zoonotic bacterial pathogen found in various food animals such as ca... more Campylobacter is a prevalent zoonotic bacterial pathogen found in various food animals such as cattle, sheep, goats, and poultry. The increasing production of crossbred cattle in Bangladesh is aimed at meeting the demand for animal protein. However, this trend also poses public health risks associated with emergence of cattle-specific Campylobacter. It is probable that there is an increased probability of transmission of pathogenic Campylobacter among humans and animals, as well as within the farm environment. Nevertheless, it has been established that Campylobacter is also a significant contributor to childhood diarrhea in Bangladesh. The objective of this study is to examine Campylobacter in animals and humans, including the risk factors that contribute to its occurrence, patterns of antimicrobial resistance, and measures that can be taken to prevent and control its spread. The study has established predominant maintenance zoonotic Campylobacter in source animals and their burden in humans is enormous. Our research is primarily focused on promoting public health by improving cleaning and sanitation practices in animal farms, which can help reduce the amount of Campylobacter present in the environment. The data and insights provided in this article can be valuable for policy planners and public health experts who are working to create effective and sustainable strategies aimed at reducing the risks associated with Campylobacter infection over the long term.
A bacteriological study of fish is critical to protecting people from potential hazards and servi... more A bacteriological study of fish is critical to protecting people from potential hazards and serving as an indicator of water contamination. The study was carried out to investigate microorganisms from the Labeo rohita. A total bacterial load was measured in the skin, gills, and intestine. It had a total bacterial load (TBL) of 1.54×10 9 CFU/g on average. The intestine had the highest average TBL of 2.09×10 9 CFU/g, while the gill had the lowest average TBL of 1.08×10 9 CFU/g. Isolated bacteria were grouped based on colony characteristics and then subjected to morphological, physiological, and biochemical analysis for identification up to the genus or species level. Staphylococcus aureus and Vibrio spp. were identified as the two microorganisms. After a thorough examination and PCR analysis, the two bacteria, S. aureus and Vibrio spp., were isolated. S. aureus was detected in skin samples from R3 and R5 fish. S. aureus was isolated from R3, R4, and R5 in the gills. S. aureus was found in intestinal samples R2, R3, R4, and R5. The presence of Vibrio spp. was found in the intestines of all fish samples tested, as well as the skin of R4 and R5, and the gills of R2, R3, R4, and R5. The 16S rRNA gene was amplified in all S. aureus isolates, while the Tox-R gene was amplified in all Vibrio spp isolates. The isolated S. aureus and Vibrio tested positive for the 16s rRNA and Tox-R genes, respectively. An antibiotic sensitivity test revealed that the majority of S. aureus and Vibrio spp were susceptible to azithromycin, ciprofloxacin, and tetracycline but resistant to amoxicillin and streptomycin.
Antimicrobial resistance (AMR) in Citrobacter freundii poses a serious challenge as this species ... more Antimicrobial resistance (AMR) in Citrobacter freundii poses a serious challenge as this species is one of the sources of nosocomial infection and causes diarrheal infections in humans. Ducks could be the potential source of multidrug-resistant (MDR) C. freundii; however, AMR profiles in C. freundii from non-human sources in Bangladesh have remained elusive. This study aimed to detect C. freundii in domestic ducks (Anas platyrhynchos domesticus) in Bangladesh and to determine their phenotypic and genotypic antibiotic susceptibility patterns. A total of 150 cloacal swabs of diseased domestic ducks were screened using culturing, staining, biochemical, polymerase chain reaction (PCR), and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) to detect C. freundii. Phenotypic and genotypic antibiotic susceptibility patterns were done by the disk diffusion method and PCR, respectively. In total, 16.67% (25/150) of the samples were positive for C. freundii. C. freundii isolates showed a range of 20% to 96% resistance to cefotaxime, gentamicin, levofloxacin, ciprofloxacin, cotrimoxazole, tetracycline, ampicillin, and cephalexin. More than 60% of the isolates were phenotypically MDR, and the index of multiple antibiotic resistance ranged from 0.07 to 0.79. Genes encoding resistance to beta-lactams [blaTEM-1-88% (22/25), blaCMY-2-56% (14/25), blaCMY-9-8% (2/25), and blaCTX-M-14-20% (5/25)], sulfonamides [sul1-52% (13/25), sul2-24% (6/25)], tetracyclines [tetA-32% (8/25) and tetB-4% (1/25)], aminoglycosides [aacC4-16% (4/25)], and fluoroquinolones [qnrA-4% (1/25), qnrB-12% (3/25), and qnrS-4% (1/25)] were detected in the isolated C. freundii. To the best of our knowledge, this is the first study in Bangladesh to detect MDR C. freundii with their associated resistance genes from duck samples. We suggest addressing the burden of diseases in ducks and humans and associated AMR issues using the One Health approach.
Antibiotics are used for the treatment and control of diseases as well as a growth promoter in li... more Antibiotics are used for the treatment and control of diseases as well as a growth promoter in livestock production in Bangladesh. The frequent use of these antibiotics in veterinary practices may lead to residue and creates some potential problems not only in livestock but also in public health issues. The presence of residues of antibiotics in animal-derived foodstuffs may induce carcinogenic and mutagenic effects and leads to the condition of an allergic reaction, and the development of antibiotic resistance in human gut bacteria. Although misuse of antibiotics in human medicine is the principal cause of the problems, some antibioticresistant bacteria originating in animals may also be the contributory factors to the resistance. However, some of the antibiotic resistance problems can be attributed to the transfer of resistant bacteria from animals to humans and resistance genes from animal pathogens and commensal bacteria to human pathogens. Even though the antibiotics and their residues in feed and food products of animal origin cause serious public health problems but little is known by society due to the lack of proper information. So, this is important to review the uses of antibiotics in food animals and insight their public health significance in Bangladesh. However, the safety levels of animal feeds and food of animal origin must be strictly observed and the antibiotics should be used in accordance with the labeled directions public awareness should be developed about the indiscriminate use of antibiotics in animals and their hazardous residual impacts on the human body. Therefore, the present review focuses on the aspects of antibiotic use in the livestock production of Bangladesh.
Background: Candida albicans is the most isolated fungal agent in a worldwide health system. Spec... more Background: Candida albicans is the most isolated fungal agent in a worldwide health system. Species distribution of Candida infection is different according to geographical regions. However, a shift in favor of non-albicans Candida species with antifungals resistance have increased as an important cause of candidemia. Objectives: This study aimed to identify the species of yeasts isolated from the blood samples of patients at the university hospital and to determine in vitro susceptibilities of three most common isolates against nine antifungal agents. Materials and methods:In total, 130 yeast isolates from 130 patients were defined the species using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Antifungal susceptibility testing was carried out using broth dilution Sensititre YeastOne panels included amphotericin B, 5-fucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Results: The most common species in all age groups was C. tropicalis (n=48, 36.9%), followed by C. albicans (n=38, 29.2%). C. glabrata (n=23, 17.7%) was more common among elderly patients, while C. parapsilosis (n=9, 6.9%) was more frequently isolated from younger patients. Antifungal susceptibility testing in Candida species expressed MIC in the low level of almost antifungal drug except for reduced fluconazole susceptibility against C. glabrata and C. tropicalis isolates. Conclusion: C. tropicalis is the most common infection in candidemic patients. Fluconazole resistance strains were found in C. glabrata and C. tropicalis, respectively. In addition, voriconazole resistance strains were found in C. tropicalis.
Campylobacter, one of the four key causes of diarrheal diseases of humans, is a zoonotic bacteria... more Campylobacter, one of the four key causes of diarrheal diseases of humans, is a zoonotic bacterial pathogen commonly found in cattle, sheep, goats and poultry. As the number of crossbred cattle steadily increases in Bangladesh through intensified livestock production to fulfill the demand of animal-source protein, the risk of pathogenic Campylobacter transmission is likely to increase in humans and animals including the farm environment. The objective of this study was to confirm the risk pathways and estimate the likelihood of entry and exposure risks of Campylobacter for cattle in the farm holdings. Following OIE risk analysis guidelines and tools, we assessed the risk level of each pathway using secondary and field observation data used in expert opinion elicitation process to formulate and confirm the risk level and their combined risk. The probable risk nodes were combined to obtain the total risk level for each specific transmission pathway using the template adapted by Zepeda-Sein based upon expert opinions. The evaluations revealed that the risk of the entry and exposure of Campylobacter is medium with medium levels of uncertainty. Moreover, the consequence pathways showed high risk with low level of uncertainty. Finally, the overall risk for transmission was evaluated as medium with medium level of uncertainty. This study suggests that there is a significant risk of Campylobacter transmission which may spread in humans, animals and successfully maintain in the farm environments. Good animal husbandry practices along with personal hygiene and sanitation practices of animal attendants including their family members are needed to minimize the risk of Campylobacter transmission from farmed cattle to humans. The findings of this study could be useful for framing functional risk reduction measures at the low-resource settings using One Health approach considering human, animal and environmental health perspectives.
Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, ... more Escherichia coli is a significant foodborne pathogen, frequently linked to hemorrhagic diarrhea, especially in developing nations, where it presents considerable public health concerns. This study was conducted to examine the virulence gene profiles and antibiotic resistance patterns of E. coli strains isolated from piper betel leaves. A total of 100 betel leaf samples, including fresh (n = 60) and ready-to-eat (n = 40) specimens, were collected and tested for the presence of E. coli using standard diagnostic techniques, such as selective culture methods, staining, latex agglutination, and polymerase chain reaction (PCR) assays. Further, the identified E. coli isolates underwent PCR-based testing for virulence genes and disk diffusion assays to assess antibiotic susceptibility. Among the 100 samples screened, 4% (n = 4/100; 95% CI: 1.57–9.84; P = 0.1126) were identified as E. coli O157, and 33% (n = 33/100; 95% CI: 24.56–42.69; P = 0.4011) were classified as non-O157 isolates. The virulence gene stx1 was found in 10.81% of isolates, while stx2, eaeA, and hlyA genes were not detected in any samples. Antibiotic resistance analysis showed that all isolates (100%, 37/37) were resistant to amoxicillin and erythromycin, with 75.68% (28/37) demonstrating resistance to tetracycline. Notably, all isolates were fully susceptible to ceftriaxone and ciprofloxacin. A majority (72.97%, 27/37) of isolates were sensitive to streptomycin, and 67.57% (25/37) were sensitive to gentamicin. Additionally, 86.48% of the E. coli isolates exhibited multidrug resistance (MDR), showing 10 resistance patterns, including 8 MDR patterns. The most common MDR pattern was AMX-TE-E, observed in 56.76% (21/37) of isolates. One isolate demonstrated resistance to six of the eight tested antibiotics across four distinct classes, with the resistance pattern AMX-TE-GEN-S-E-AZM. The MAR indices for E. coli isolates ranged between 0.25 and 0.75. These findings highlight the significant threat posed to global public health by multidrug-resistant shiga toxin-producing E. coli found on piper betel leaves in urban environments.
We aimed to estimate the overall apparent prevalence, true prevalence, and the spatial, temporal,... more We aimed to estimate the overall apparent prevalence, true prevalence, and the spatial, temporal, and test-specific burden of bovine tuberculosis in Bangladesh. PubMed, Web of Science, Scopus, Google Scholar, and BanglaJOL were searched for bovine tuberculosis publications in Bangladesh from 1 January 1970 to 23 June 2023. Of 142 articles screened, systematic review and meta-analysis were performed on 22 (15.5%) articles. The apparent estimated bovine tuberculosis prevalence was 7%. The apparent Bayesian pooled mean bovine tuberculosis prevalences based on caudal fold test and single intradermal comparative tuberculin test were 7.83% and 9.89%, respectively, and the true pooled mean prevalences were 10.39% and 10.48%, respectively. Targeted interventions are recommended for districts with higher prevalence to effectively reduce the bovine tuberculosis burden in those areas. Current diagnostic practices employed in Bangladesh may not accurately reflect the bovine tuberculosis burden. Our findings highlight the need for better diagnostic tools and supplemental testing methods to ensure accurate diagnosis and surveillance. Efforts should prioritize obtaining 'true' prevalence estimates corrected for misclassification bias, rather than relying solely on apparent prevalence. Underestimating the bovine tuberculosis burden could result in inadequate resource allocation and hinder the implementation of effective control measures.
Objectives:
Citrobacter freundii is a prevalent source of nosocomial infections and a well-known ... more Objectives: Citrobacter freundii is a prevalent source of nosocomial infections and a well-known cause of diarrheal diseases. In recent years, it has also become increasingly resistant to various antimicrobials. In this study, we screened and characterized a multidrug-resistant (MDR) C. freundii isolate obtained from a domesticated diseased duck to better understand the genetic features, molecular epidemiology, and underlying factors linked to the antimicrobial resistance genes (ARGs) and virulence factor genes (VFGs) of the isolate.
Methods: The C. freundii BAU_TM8 strain was isolated using culturing, staining, biochemical, polymerase chain reaction, and Matrix-assisted laser desorption/ionization-time of flight methods. The MDR properties of the strain were determined by a disk diffusion test. The genomic sequence of C. freundii BAU_TM8 was performed using the Illumina NextSeq2000 platform. The ARGs, VFGs, and genomic functional characteristics of the C. freundii BAU_TM8 strain were identified using several open-source databases.
Results: The sequence type of this strain was ST669, and the pathogenicity index of the strain was 0.919. Moreover, the strain had an estimated genome length of 5,797,806 bp, harboring 62 contigs, a G + C content of 54.32 %, and five contig L50s with an N50 value of 443,947 bp. Using phylogenetic analysis, this strain was closely related to two strains isolated from human and environmental samples in the USA and China despite huge geographical distances. The C. freundii BAU_TM8 strain consisted of 40 AGRs encoding resistance to 19 antimicrobial categories, e.g., fluoroquinolones, macrolides, folate pathway antagonists, aminoglycosides, tetracyclines, cephalosporins, and others. According to the phenotypic assay and genome sequence, the sensitivity and specificity of resistance profiles of the strain were 100 % and 20 %, respectively. Moreover, the virulence factor database detected 66 VFGs in this strain. This strain contained 1581 subsystems, having 33 % subsystem coverage and 2275 genes encoding amino acid derivatives, carbohydrate metabolism, protein metabolism, cofactors, vitamins, prosthetic groups, pigments, respiration, motility and chemotaxis, stress response, DNA metabolism, nucleosides and nucleotides, and others.
Conclusions: To the best of our knowledge, this is the first WGS report of C. freundii from a domesticated duck in Bangladesh. The ubiquitous occurrence of ARGs and VFGs in the C. freundii BAU_TM8 strain detected in this study highlights the growing concern about antimicrobial resistance in humans, animals, and environments.
In Bangladesh, little is known about the role of climatic factors influencing spatio-temporal occ... more In Bangladesh, little is known about the role of climatic factors influencing spatio-temporal occurrence among different food grains of aflatoxins, which have been linked to liver cancer cases and other health hazards. In this study, 252 food grain samples of 10 types were collected from retail markets at 18 districts, pre-monsoon, monsoon and post-monsoon seasons during February-September, 2018. Occurrence and concentration of total aflatoxins in the samples were analysed by a direct competitive enzyme-linked immunosorbent assay, and compared with climatic data (temperature, humidity, rainfall, and sunshine hours). Contamination of aflatoxins was found in approx. 38% (n=96) of the total samples, with highest occurrence in groundnuts (82%), followed by corn grains (70%), chick pea (54.5%), wheat grain (50%) and green gram (42.9%). Aflatoxins occurrence was moderate in split chick pea (30.8%), yellow pea (28.2%), black gram (27.8%), and lentils (27.6%), while the lowest in grass pea (17.6%). Aflatoxins concentration was found to exceed the European Union permissible limit (≤5 µg kg-1) in 33 (13.1%) samples. Overall, approximately 5.6%, 7.5%, and 25.0% samples were contaminated with high (10-19 ppb), medium (5-9 ppb) and low (1-4 ppb) concentrations of aflatoxins, respectively. High level concentration of aflatoxins was more frequent in groundnut (36%) and wheat grain (20%), in comparison to other types. Occurrence of aflatoxins during premonsoon was detected among 21% (19/91) samples, which increased to ca. 30% (36/119) during monsoon, and 98% (41/42) during post-monsoon. However, aflatoxins mean concentration during post-monsoon was comparatively low than the other seasons. Variations in aflatoxins monthly prevalence correlated significantly with relative humidity (p ≤ 0.01) and rainfall (p≤ 0.05), when a 1-month time lag was considered. Therefore, predisposing climatic conditions, i.e., rainfall incidences and persistence of higher relative humidity in the previous month(s), have salient influence on aflatoxins occurrence, potentially impacting both pre-harvest and stored food grains. This study underscores the need of a more holistic monitoring of aflatoxins in agricultural products for a longer term, and adoption of proper intervention measures for food grains while being stored and before consumption.
In the intricate tapestry of human existence, few threads are as fundamental and indispensable as... more In the intricate tapestry of human existence, few threads are as fundamental and indispensable as food (Morawicki and Díaz González, 2018). It sustains us, fuels our endeavors, and serves as a cornerstone of culture and society (Fardet and Rock, 2020). Yet, amidst the abundance and variety, lurks a silent menacethe specter of unsafe and insecure food (Tariqujjaman et al., 2023). This editorial endeavors to shed light on the critical importance of food safety and security, emphasizing the pivotal role of the Asian-Australasian Journal of Food Safety and Security (AAJFSS) in advancing knowledge and safeguarding public health in this domain. At the core of AAJFSS's mission lies a commitment to fostering rigorous scientific inquiry into all facets of food safety and security (
As we navigate the complexities of the modern world, the pursuit of scientific understanding in m... more As we navigate the complexities of the modern world, the pursuit of scientific understanding in medical and biological research becomes increasingly vital (Betz et al., 2023). The Asian Journal of Medical and Biological Research (AJMBR) stands as a beacon in this pursuit, dedicated to the dissemination of high-quality and innovative research spanning a vast array of disciplines (
Background and Aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ile... more Background and Aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ileitis, infertility, and abortion. Thus, this study aimed to estimate the prevalence of Campylobacter spp. in farming sheep and to detect risk factors, molecular patterns, and antimicrobial susceptibility status of these pathogens. Materials and Methods: Four hundred and eight fecal samples were collected from 12 flocks in the Mymensingh and Sherpur districts. Samples were tested by both basic (culture and biochemical tests) and molecular (initially 16S rRNA and later hipO gene-based polymerase chain reaction). Furthermore, the antimicrobial susceptibility status of Campylobacter jejuni was confirmed using disk diffusion. Flock-and animal-level data were captured using semi-structured interviews with farm owners under bivariate and multivariate logistic regression analyses to confirm the risk factors for Campylobacterpositive status. Results: The prevalence of C. jejuni staining at the animal and flock levels was 8.82% (36/408) and 66.70% (8/12), respectively. The age of sheep was identified as an important risk factor. Up to 1 year of age, sheep were 3.78 times more likely to be infected with C. jejuni (95% confidence interval: 1.0736-13.3146, p = 0.038). Of the 36 isolates of C. jejuni, all were found to be fully susceptible (100%) to gentamicin and ciprofloxacin. In this study, three antimicrobial agents, oxytetracycline, azithromycin, and ceftriaxone, were fully resistant (100%). The majority of isolates were resistant to a combination of 4-6 antimicrobial agents. Conclusion: The present study highlights the predominant maintenance of zoonotic Campylobacter species in sheep, and their burden on human health is enormous. Therefore, environmental, animal, and human health needs to be focused under a One Health lens to mitigate the occurrence of Campylobacter in farm settings and to prevent further introduction to animals and humans.
We announce the genome sequence of the Citrobacter portucalensis BAU_133-2 strain isolated from a... more We announce the genome sequence of the Citrobacter portucalensis BAU_133-2 strain isolated from a domestic duck. Our assembled genome contained a length of 4.8 Mb, 110.0× genome coverage, 51.91% of an average GC content, 1 plasmid, 1 CRISPR array, 8 prophages, 27 antibiotic resistance genes, and 75 virulence factor genes.
Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused b... more Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused by Mycobacterium bovis. This study aimed to evaluate the efficacy of the interferon-gamma (IFN-γ) assay and single-intradermal comparative tuberculin test (SICTT) in detecting bTB. Materials and Methods: In an earlier study, 150 positive, 83 inconclusive, and 480 negative animals from 24 cattle herds were screened using SICTT. From these groups, 125 positive, 17 inconclusive, and six negative animals were subsequently verified using the IFN-γ assay. Single-intradermal comparative tuberculin test outcomes were interpreted according to standard guidelines, whereas blood samples were collected and stimulated with purified protein derivatives. Sandwich enzyme-linked immunosorbent assay was used to measure secreted IFN-γ. Concordant and Bayesian latent class analyses were performed to evaluate test performance. Results: Results from the IFN-γ assay revealed that 83.2%, 64.7%, and 16.67% of the animals were positive in the SICTTpositive, inconclusive, and negative animal categories, respectively. Sensitivity (SE) and specificity (SP) of SICTT were 83.9% (95% confidence interval [CI]: 77.4-90.1) and 95.7% (95% CI: 86.9-99.7), respectively. Sensitivity and SP for the IFN-γ assay were 78.9% (95% CI: 71.9-85.4) and 83.9% (65.9-95.9), respectively. The use of both tests in parallel increases the SE of bTB detection (~94%), compared with SICTT alone. Conclusion: Use of the IFN-γ assay with SICTT in parallel, predominantly on cattle demonstrating an inconclusive SICTT outcome, boosts bTB detection rate in low resource settings.
We sequenced a multidrug-resistant strain of Citrobacter freundii, 132-2, isolated from a cloacal... more We sequenced a multidrug-resistant strain of Citrobacter freundii, 132-2, isolated from a cloacal swab sample of a domestic duck. The whole genome of the C. freundii 132-2 strain had a length of 5,097,592 bp, 62 contigs, two plasmids, and an average G1C content of 51.85%, with a 105.0Â genome coverage.
Bovine tuberculosis (bTB) is considered to be an endemic disease having zoonotic importance in Ba... more Bovine tuberculosis (bTB) is considered to be an endemic disease having zoonotic importance in Bangladesh, but no economic analysis describing the burden of this disease has been reported so far. The objective of this study was to calculate the economic losses of bTB in crossbred farming cattle focused mainly on livestock production loss including decreased milk and meat production, neonatal deaths, infertility and other associated losses in two selected cattle-dense districts of Bangladesh. Utilizing the data from a cross-sectional survey on bTB prevalence conducted in 2019 combined with field interview data collection on different financial parameters on livestock goods and published secondary data, estimation of economic loss for a single year in two studied district (Dhaka and Mymensingh) of Bangladesh was done. The study confirmed an annual estimated economic loss due to bTB in farming cattle was BDT 1347.72 million (95% CI = 997.43-1801.65), equivalent to US$ 16.04 million (95% CI= 11.87-21.45). The study showed that the highest economic loss was due to decreased milk production (BDT 697.25 million) followed by decreased meat production (BDT 531.22 million), other pertinent losses (vet health care, cleaning and disinfection costs, and restocking costs, if required), infertility and neonatal deaths. Due to a high animal-level prevalence of bTB in Dhaka, the study confirmed a higher economic loss in this district (BDT 717.80 million, 95% CI= 617.61-819.72) than that in Mymensingh (BDT 629. 92 million, 95% CI= 379.82-981.93). The study provides an in-depth insight into the impact of bTB on livestock productivity in two cattle rearing districts of Bangladesh. The model developed through this study could be applied to the estimation of the overall bTB burden in Bangladesh.
This study aimed to investigate Campylobacter jejuni, a major cause of food-borne bacterial infec... more This study aimed to investigate Campylobacter jejuni, a major cause of food-borne bacterial infections worldwide, in fresh vegetables from five upzillas (Mymensingh, Trishal, Bhaluka, Muktagacha, and Fulbaria) in the Mymensingh district between July 2020 and April 2023. Using cultural, biochemical, and molecular techniques, 100 fresh vegetable samples (including tomato, carrot, cucumber, green chili, and coriander) were examined for C. jejuni. The isolates were further tested for virulence genes and antimicrobial susceptibility. Out of the 100 samples, 23% were confirmed as C. jejuni, by 16S rRNA gene-based polymerase chain reaction and all were found to be virulent with cytolethal distending toxins (cdtA, cdtB and cdtC genes). Antibiotic susceptibility testing revealed resistance to amoxicillin (47.83%), tetracycline (43.48%), and streptomycin (39.13%) among the isolates. However, ceftriaxone and ciprofloxacin were effective against 47.83% and 43.48% of the isolates, respectively. Moreover, 52.17% of the isolates were sensitive to erythromycin. Alarmingly, 34.78% of the C. jejuni isolates exhibited multidrug resistance (MDR) with eight different antibiotic resistance patterns, including four MDR patterns. These findings highlight the presence of virulent and antibiotic-resistant C. jejuni in fresh vegetables, emphasizing the need for monitoring and control to ensure food safety and public health issues.
Fungal endophyte is a fungal that lives in plant organism as mutualism association. The role of f... more Fungal endophyte is a fungal that lives in plant organism as mutualism association. The role of fungal endophyte is a growth promoter or/and microbial pathogen inhibitor. This study investigated antifungal activity of Colletotrichum truncatum E10, an endophytic fungus derived from Musa acuminata (AAA group), against 7 isolates of Aspergillus obtained from lower respiratory samples of COVID-19 patients. In addition, IAA production of this strain was also observed. All isolates of Aspergillus were identified using MALDI-TOF MS. The fungal endophyte, C. truncatum E10, was screened for IAA induction with and without 0.1, 2 and 8 mg/mL of L-tryptophan based on colorimetric method using Salkowski reagent which produced pinkish to reddish solution indicating the presence of IAA. Antagonist activity was based on dual culture assay measured in colony growth inhibition (CGI). C. truncatum E10 produced the highest IAA concentration of 112.81±0.12 µg/mL when 8 mg/mL of L-tryptophan added. The strong antagonist activities were shown by C. truncatum E10 against 5 Aspergillus isolates including 2 A. fumigatus: sp442/6 (CGI=57.835.11%) and sp269/11 (CGI=53.018.52%), 1 A. niger sp26/7 (CGI=57.8315.33%) and 2 A. flavus: sp26/7 (CGI=56.6313.63%) and sp36/7 (CGI=57.230.85%), whereas the colony growth inhibition (CGI) of other 2 isolates including A. fumigatus sp567/6 and A. flavus sp269/11 were less than 50%. In this study, C. truncatum E10 produced substances that inhibited human fungal pathogen including A. fumigatus, A. flavus and A. niger. Moreover, it can produce IAA activity. Further investigations are being conducted to expand the plant growth promotion effects and determine IAA biosynthesis pathway. For antifungal activity, the bioactive metabolites produced by this endophytic fungal isolate should be characterized to specify the effective compounds.
Campylobacter is a prevalent zoonotic bacterial pathogen found in various food animals such as ca... more Campylobacter is a prevalent zoonotic bacterial pathogen found in various food animals such as cattle, sheep, goats, and poultry. The increasing production of crossbred cattle in Bangladesh is aimed at meeting the demand for animal protein. However, this trend also poses public health risks associated with emergence of cattle-specific Campylobacter. It is probable that there is an increased probability of transmission of pathogenic Campylobacter among humans and animals, as well as within the farm environment. Nevertheless, it has been established that Campylobacter is also a significant contributor to childhood diarrhea in Bangladesh. The objective of this study is to examine Campylobacter in animals and humans, including the risk factors that contribute to its occurrence, patterns of antimicrobial resistance, and measures that can be taken to prevent and control its spread. The study has established predominant maintenance zoonotic Campylobacter in source animals and their burden in humans is enormous. Our research is primarily focused on promoting public health by improving cleaning and sanitation practices in animal farms, which can help reduce the amount of Campylobacter present in the environment. The data and insights provided in this article can be valuable for policy planners and public health experts who are working to create effective and sustainable strategies aimed at reducing the risks associated with Campylobacter infection over the long term.
A bacteriological study of fish is critical to protecting people from potential hazards and servi... more A bacteriological study of fish is critical to protecting people from potential hazards and serving as an indicator of water contamination. The study was carried out to investigate microorganisms from the Labeo rohita. A total bacterial load was measured in the skin, gills, and intestine. It had a total bacterial load (TBL) of 1.54×10 9 CFU/g on average. The intestine had the highest average TBL of 2.09×10 9 CFU/g, while the gill had the lowest average TBL of 1.08×10 9 CFU/g. Isolated bacteria were grouped based on colony characteristics and then subjected to morphological, physiological, and biochemical analysis for identification up to the genus or species level. Staphylococcus aureus and Vibrio spp. were identified as the two microorganisms. After a thorough examination and PCR analysis, the two bacteria, S. aureus and Vibrio spp., were isolated. S. aureus was detected in skin samples from R3 and R5 fish. S. aureus was isolated from R3, R4, and R5 in the gills. S. aureus was found in intestinal samples R2, R3, R4, and R5. The presence of Vibrio spp. was found in the intestines of all fish samples tested, as well as the skin of R4 and R5, and the gills of R2, R3, R4, and R5. The 16S rRNA gene was amplified in all S. aureus isolates, while the Tox-R gene was amplified in all Vibrio spp isolates. The isolated S. aureus and Vibrio tested positive for the 16s rRNA and Tox-R genes, respectively. An antibiotic sensitivity test revealed that the majority of S. aureus and Vibrio spp were susceptible to azithromycin, ciprofloxacin, and tetracycline but resistant to amoxicillin and streptomycin.
Antimicrobial resistance (AMR) in Citrobacter freundii poses a serious challenge as this species ... more Antimicrobial resistance (AMR) in Citrobacter freundii poses a serious challenge as this species is one of the sources of nosocomial infection and causes diarrheal infections in humans. Ducks could be the potential source of multidrug-resistant (MDR) C. freundii; however, AMR profiles in C. freundii from non-human sources in Bangladesh have remained elusive. This study aimed to detect C. freundii in domestic ducks (Anas platyrhynchos domesticus) in Bangladesh and to determine their phenotypic and genotypic antibiotic susceptibility patterns. A total of 150 cloacal swabs of diseased domestic ducks were screened using culturing, staining, biochemical, polymerase chain reaction (PCR), and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) to detect C. freundii. Phenotypic and genotypic antibiotic susceptibility patterns were done by the disk diffusion method and PCR, respectively. In total, 16.67% (25/150) of the samples were positive for C. freundii. C. freundii isolates showed a range of 20% to 96% resistance to cefotaxime, gentamicin, levofloxacin, ciprofloxacin, cotrimoxazole, tetracycline, ampicillin, and cephalexin. More than 60% of the isolates were phenotypically MDR, and the index of multiple antibiotic resistance ranged from 0.07 to 0.79. Genes encoding resistance to beta-lactams [blaTEM-1-88% (22/25), blaCMY-2-56% (14/25), blaCMY-9-8% (2/25), and blaCTX-M-14-20% (5/25)], sulfonamides [sul1-52% (13/25), sul2-24% (6/25)], tetracyclines [tetA-32% (8/25) and tetB-4% (1/25)], aminoglycosides [aacC4-16% (4/25)], and fluoroquinolones [qnrA-4% (1/25), qnrB-12% (3/25), and qnrS-4% (1/25)] were detected in the isolated C. freundii. To the best of our knowledge, this is the first study in Bangladesh to detect MDR C. freundii with their associated resistance genes from duck samples. We suggest addressing the burden of diseases in ducks and humans and associated AMR issues using the One Health approach.
Antibiotics are used for the treatment and control of diseases as well as a growth promoter in li... more Antibiotics are used for the treatment and control of diseases as well as a growth promoter in livestock production in Bangladesh. The frequent use of these antibiotics in veterinary practices may lead to residue and creates some potential problems not only in livestock but also in public health issues. The presence of residues of antibiotics in animal-derived foodstuffs may induce carcinogenic and mutagenic effects and leads to the condition of an allergic reaction, and the development of antibiotic resistance in human gut bacteria. Although misuse of antibiotics in human medicine is the principal cause of the problems, some antibioticresistant bacteria originating in animals may also be the contributory factors to the resistance. However, some of the antibiotic resistance problems can be attributed to the transfer of resistant bacteria from animals to humans and resistance genes from animal pathogens and commensal bacteria to human pathogens. Even though the antibiotics and their residues in feed and food products of animal origin cause serious public health problems but little is known by society due to the lack of proper information. So, this is important to review the uses of antibiotics in food animals and insight their public health significance in Bangladesh. However, the safety levels of animal feeds and food of animal origin must be strictly observed and the antibiotics should be used in accordance with the labeled directions public awareness should be developed about the indiscriminate use of antibiotics in animals and their hazardous residual impacts on the human body. Therefore, the present review focuses on the aspects of antibiotic use in the livestock production of Bangladesh.
Background: Candida albicans is the most isolated fungal agent in a worldwide health system. Spec... more Background: Candida albicans is the most isolated fungal agent in a worldwide health system. Species distribution of Candida infection is different according to geographical regions. However, a shift in favor of non-albicans Candida species with antifungals resistance have increased as an important cause of candidemia. Objectives: This study aimed to identify the species of yeasts isolated from the blood samples of patients at the university hospital and to determine in vitro susceptibilities of three most common isolates against nine antifungal agents. Materials and methods:In total, 130 yeast isolates from 130 patients were defined the species using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Antifungal susceptibility testing was carried out using broth dilution Sensititre YeastOne panels included amphotericin B, 5-fucytosine, fluconazole, itraconazole, voriconazole, posaconazole, anidulafungin, micafungin, and caspofungin. Results: The most common species in all age groups was C. tropicalis (n=48, 36.9%), followed by C. albicans (n=38, 29.2%). C. glabrata (n=23, 17.7%) was more common among elderly patients, while C. parapsilosis (n=9, 6.9%) was more frequently isolated from younger patients. Antifungal susceptibility testing in Candida species expressed MIC in the low level of almost antifungal drug except for reduced fluconazole susceptibility against C. glabrata and C. tropicalis isolates. Conclusion: C. tropicalis is the most common infection in candidemic patients. Fluconazole resistance strains were found in C. glabrata and C. tropicalis, respectively. In addition, voriconazole resistance strains were found in C. tropicalis.
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Papers by Dr. S. M. Lutful Kabir
Citrobacter freundii is a prevalent source of nosocomial infections and a well-known cause of diarrheal diseases. In recent years, it has also become increasingly resistant to various antimicrobials. In this study, we screened and characterized a multidrug-resistant (MDR) C. freundii isolate obtained from a domesticated diseased duck to better understand the genetic features, molecular epidemiology, and underlying factors linked to the antimicrobial resistance genes (ARGs) and virulence factor genes (VFGs) of the isolate.
Methods:
The C. freundii BAU_TM8 strain was isolated using culturing, staining, biochemical, polymerase chain reaction, and Matrix-assisted laser desorption/ionization-time of flight methods. The MDR properties of the strain were determined by a disk diffusion test. The genomic sequence of C. freundii BAU_TM8 was performed using the Illumina NextSeq2000 platform. The ARGs, VFGs, and genomic functional characteristics of the C. freundii BAU_TM8 strain were identified using several open-source databases.
Results:
The sequence type of this strain was ST669, and the pathogenicity index of the strain was 0.919. Moreover, the strain had an estimated genome length of 5,797,806 bp, harboring 62 contigs, a G + C content of 54.32 %, and five contig L50s with an N50 value of 443,947 bp. Using phylogenetic analysis, this strain was closely related to two strains isolated from human and environmental samples in the USA and China despite huge geographical distances. The C. freundii BAU_TM8 strain consisted of 40 AGRs encoding resistance to 19 antimicrobial categories, e.g., fluoroquinolones, macrolides, folate pathway antagonists, aminoglycosides, tetracyclines, cephalosporins, and others. According to the phenotypic assay and genome sequence, the sensitivity and specificity of resistance profiles of the strain were 100 % and 20 %, respectively. Moreover, the virulence factor database detected 66 VFGs in this strain. This strain contained 1581 subsystems, having 33 % subsystem coverage and 2275 genes encoding amino acid derivatives, carbohydrate metabolism, protein metabolism, cofactors, vitamins, prosthetic groups, pigments, respiration, motility and chemotaxis, stress response, DNA metabolism, nucleosides and nucleotides, and others.
Conclusions:
To the best of our knowledge, this is the first WGS report of C. freundii from a domesticated duck in Bangladesh. The ubiquitous occurrence of ARGs and VFGs in the C. freundii BAU_TM8 strain detected in this study highlights the growing concern about antimicrobial resistance in humans, animals, and environments.
Citrobacter freundii is a prevalent source of nosocomial infections and a well-known cause of diarrheal diseases. In recent years, it has also become increasingly resistant to various antimicrobials. In this study, we screened and characterized a multidrug-resistant (MDR) C. freundii isolate obtained from a domesticated diseased duck to better understand the genetic features, molecular epidemiology, and underlying factors linked to the antimicrobial resistance genes (ARGs) and virulence factor genes (VFGs) of the isolate.
Methods:
The C. freundii BAU_TM8 strain was isolated using culturing, staining, biochemical, polymerase chain reaction, and Matrix-assisted laser desorption/ionization-time of flight methods. The MDR properties of the strain were determined by a disk diffusion test. The genomic sequence of C. freundii BAU_TM8 was performed using the Illumina NextSeq2000 platform. The ARGs, VFGs, and genomic functional characteristics of the C. freundii BAU_TM8 strain were identified using several open-source databases.
Results:
The sequence type of this strain was ST669, and the pathogenicity index of the strain was 0.919. Moreover, the strain had an estimated genome length of 5,797,806 bp, harboring 62 contigs, a G + C content of 54.32 %, and five contig L50s with an N50 value of 443,947 bp. Using phylogenetic analysis, this strain was closely related to two strains isolated from human and environmental samples in the USA and China despite huge geographical distances. The C. freundii BAU_TM8 strain consisted of 40 AGRs encoding resistance to 19 antimicrobial categories, e.g., fluoroquinolones, macrolides, folate pathway antagonists, aminoglycosides, tetracyclines, cephalosporins, and others. According to the phenotypic assay and genome sequence, the sensitivity and specificity of resistance profiles of the strain were 100 % and 20 %, respectively. Moreover, the virulence factor database detected 66 VFGs in this strain. This strain contained 1581 subsystems, having 33 % subsystem coverage and 2275 genes encoding amino acid derivatives, carbohydrate metabolism, protein metabolism, cofactors, vitamins, prosthetic groups, pigments, respiration, motility and chemotaxis, stress response, DNA metabolism, nucleosides and nucleotides, and others.
Conclusions:
To the best of our knowledge, this is the first WGS report of C. freundii from a domesticated duck in Bangladesh. The ubiquitous occurrence of ARGs and VFGs in the C. freundii BAU_TM8 strain detected in this study highlights the growing concern about antimicrobial resistance in humans, animals, and environments.