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A representative sample of 20 isolates of Salmonella weltevreden strains from stool cultures of patients admitted at the University Hospital, Kuala Lumpur, Malaysia were analyzed. All the strains were susceptible to ampicillin,... more
A representative sample of 20 isolates of Salmonella weltevreden strains from stool cultures of patients admitted at the University Hospital, Kuala Lumpur, Malaysia were analyzed. All the strains were susceptible to ampicillin, ceftriaxone, ciprofloxacin, chloramphenicol, tetracycline, trimethoprim, gentamicin and co-trimoxazole. Ribosomal RNA gene restriction pattern analysis of PstI-digested DNA gave three ribotypes while pulsed-field gel electrophoresis (PFGE) analysis of XbaI-digested DNA gave ten distinct profiles. PFGE was more discriminative than ribotyping in distinguishing the strains. The majority of the strains analyzed were very closely related with similarity coefficient values ranging from 0.8 to 1.0. Both PFGE and ribotyping could distinguish one of the strains which was obtained from a patient following a bone marrow transplant for beta-thalassemia major, indicating that this particular strain was unrelated to the rest of the strains from patients with acute gastroen...
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Research Interests: Engineering, Colombia, Biology, Argentina, Medicine, and 14 moreMolecular Epidemiology, Biological Sciences, Virulence, Phylogeny, Humans, Cluster Analysis, Typhoid Fever, MDR Salmonella typhi, Pulsed field gel electrophoresis (PFGE), Outbreak, subtyping, Salmonella enterica, Medical and Health Sciences, and Salmonella Typhi
The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio... more
The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223.
Xia in 1986 combined Gracilaria salicornia, G. canaliculata (G. crassa), G. cacalia and G. minor into one species: G. salicornia. Two morphological variants of G. salicornia were collectedfrom different localities in Malaysia. Variant A... more
Xia in 1986 combined Gracilaria salicornia, G. canaliculata (G. crassa), G. cacalia and G. minor into one species: G. salicornia. Two morphological variants of G. salicornia were collectedfrom different localities in Malaysia. Variant A collected from Morib, Selangor grew on the roots of Avicennia. The samples showed absenceof main axis; segmented constrictions throughout; cylindrical or slightlycompressed thalli. Variant B was collected from the mudflats of TanjungTuan, growing on rocks, coral or forming mats on the mud. ...
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Abstract: Field samplings were conducted during the dry period in April 2004 on nine rivers in the Northeast part of Langkawi Island, Kedah, Malaysia. The microbiological quality of river water was determined by enumerating the indicator... more
Abstract: Field samplings were conducted during the dry period in April 2004 on nine rivers in the Northeast part of Langkawi Island, Kedah, Malaysia. The microbiological quality of river water was determined by enumerating the indicator organisms such as total faecal coliforms (TC), faecal coliforms (FC) and faecal streptococci (FS) and pathogenic enteric bacteria such as Salmonella spp., Vibrios spp and Shigella spp. TC, FC and FS were detected in only 22%, 11% and 22% of the marine samples respectively. The mean ...
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A PCR-based assay that can simultaneously detect and differentiate five different types of nosocomial bacterial pathogens was developed. Six pairs of selected primers targeting femA (132 bp) and mecA (310 bp) of methicillin-resistant... more
A PCR-based assay that can simultaneously detect and differentiate five different types of nosocomial bacterial pathogens was developed. Six pairs of selected primers targeting femA (132 bp) and mecA (310 bp) of methicillin-resistant Staphylococcus aureus, gltA (722 bp) of Acinetobacter baumannii, phoA (903 bp) of Escherichia coli, mdh (364 bp) of Klebsiella pneumoniae and oprL (504 bp) of Pseudomonas aeruginosa were used in this study. The conditions were optimized for the multiplex PCR to ensure specific amplification of the selected targets. Sensitivity and specificity tests were also carried out using a blind test approach on 50 bacterial cultures and resulted in 100% for both positive and negative predictive values.
Research Interests: Microbiology, Complementary and Alternative Medicine, Biology, Medicine, Humans, and 12 moreEscherichia coli, Staphylococcus aureus, Polymerase Chain Reaction, Pseudomonas aeruginosa, Bacterial infections, Pseudomonas Aeruginosa, Acinetobacter baumannii, Sensitivity and Specificity, Methicillin Resistant Staphylococcus Aureus, Klebsiella pneumoniae, Cross Infection, and multiplex polymerase chain reaction
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<p>The prevalence of <i>Y. enterocolitica</i> determined by using a duplex PCR targeting the <i>Y. enterocolitica</i>-specific 16S rRNA and <i>ail</i> genes <a... more
<p>The prevalence of <i>Y. enterocolitica</i> determined by using a duplex PCR targeting the <i>Y. enterocolitica</i>-specific 16S rRNA and <i>ail</i> genes <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106329#pone.0106329-Wannet1" target="_blank">[11]</a> was 2/52 (3.8%).</p><p><sup><i>a</i></sup>CIN, Cefsulodin-Irgasan-Novobiocin.</p><p><sup><i>b</i></sup>mCIN, modified CIN.</p><p><sup><i>c</i></sup>PBS, phosphate buffered saline, a cold enrichment at 4°C for three weeks <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0106329#pone.0106329-Johnson1" target="_blank">[8]</a>.</p><p><sup><i>d</i></sup>KOH, post-enrichment alkaline treatment.</p><p>Recovery rate of <i>Y. enterocolitica</i> from the 52 naturally contaminated rectal swabs from swine.</p
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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit:
Molecular characterization of a total of 54 isolates of Salmonella typhi from Santiago, Chile, was performed by pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases: XbaI... more
Molecular characterization of a total of 54 isolates of Salmonella typhi from Santiago, Chile, was performed by pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases: XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3'), and SpeI (5'-ACTAGT-3'). Thirteen of the 54 isolates were obtained from environmental sources (sewage and river water), and the rest were isolates from clinical cases of typhoid fever. Considerable genetic diversity was detected among the human isolates obtained in 1994, as evidenced by the presence of 14 to 19 different PFGE patterns among 20 human isolates, with F (coefficient of similarity) values ranging from 0.69 to 1.0 (XbaI), 0.61 to 1.0 (AvrII), and 0.70 to 1.0 (SpeI). A total of eight phage types were detected among these 20 isolates, with 50% possessing the E1 or 46 phage type. There was no correlation between PFGE pattern and phage types. Similar diversity was seen among 21 isolates ob...
Research Interests: Chile, Multidisciplinary, Genetic Diversity, Molecular typing, Humans, and 11 moreRiver water, Applied Environmental Microbiology, Typhoid Fever, Molecular Characterization, Sewage, Fresh water, Pulsed field gel electrophoresis (PFGE), Genetic variation, Water Microbiology, Pattern Detection, and Salmonella Typhi
Research Interests: Genetics, Immune response, Health Care, Biology, Public Health, and 15 morePapua New Guinea, Medicine, Genetic Diversity, Clinical Microbiology, Biological Sciences, Humans, Developing World, Disease Severity, Molecular Characterization, Gel electrophoresis, Clinical Presentation, Pattern Detection, Genetic factors, Medical and Health Sciences, and HIV infections
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Introduction.Acinetobacter calcoaceticus-baumanniicomplex (ACB complex) is a leading opportunistic pathogen in intensive care units (ICUs). Effective control of spread requires understanding of its epidemiological relatedness. This study... more
Introduction.Acinetobacter calcoaceticus-baumanniicomplex (ACB complex) is a leading opportunistic pathogen in intensive care units (ICUs). Effective control of spread requires understanding of its epidemiological relatedness. This study aims to determine the genetic relatedness and antibiotic susceptibilities of ACB complex in an ICU in Malaysia.Methodology. Pulsed field gel electrophoresis (PFGE), E-test, and disk diffusion were used for isolates characterization.Results. During the study period (December 2011 to June 2012), 1023 patients were admitted to the ICU and 44 ACB complex (blood,n=21, and blind bronchial aspirates,n=23) were recovered from 38 ICU patients. Six isolates were from non-ICU patients. Of the 44 ICU isolates, 88.6% exhibited multidrug-resistant (MDR) patterns. There was high degree of resistance, with minimum inhibitory concentration90(MIC90) of >32μg/mL for carbapenems and ≥256μg/mL for amikacin, ampicillin/sulbactam, and cefoperazone/sulbactam. Isolates f...
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Acinetobacter baumannii, genomic species 3 and 13TU are being increasingly reported as the most important Acinetobacter species that cause infections in hospitalized patients. These Acinetobacter species are grouped in the Acinetobacter... more
Acinetobacter baumannii, genomic species 3 and 13TU are being increasingly reported as the most important Acinetobacter species that cause infections in hospitalized patients. These Acinetobacter species are grouped in the Acinetobacter calcoaceticus- Acinetobacter baumannii (Acb) complex. Differentiation of the species in the Acb-complex is limited by phenotypic methods. Therefore, in this study, amplified ribosomal DNA restriction analysis (ARDRA) was applied to confirm the identity A. baumannii strains as well as to differentiate between the subspecies. One hundred and eighty-five strains from Intensive Care Unit, Universiti Malaya Medical Center (UMMC) were successfully identified as A. baumannii by ARDRA. Acinetobacter genomic species 13TU and 15TU were identified in 3 and 1 strains, respectively. ARDRA provides an accurate, rapid and definitive approach towards the identification of the species level in the genus Acinetobacter. This paper reports the first application ARDRA in...
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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with... more
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit:
We developed a rapid pulsed-field gel electrophoresis (PFGE) method that required 3 days to complete, an improvement over the standard method that required as many as 8 days. The accuracy and reproducibility of the rapid method were... more
We developed a rapid pulsed-field gel electrophoresis (PFGE) method that required 3 days to complete, an improvement over the standard method that required as many as 8 days. The accuracy and reproducibility of the rapid method were verified by analysis of DNA band sizes of our control group B streptococcus isolate. The rapid method was superior to the standard method, providing more precise molecular sizing and gels of higher image quality. The reproducibility of rapid PFGE substantiated its value and continued use.
Research Interests: Microbiology, Technology, Biology, Medicine, Image Quality, and 15 moreClinical Microbiology, Biological Sciences, Humans, Method, Bacteria, IT Value, Electrophoresis, Reproducibility of Results, Streptococcus agalactiae, Gel electrophoresis, Sensitivity and Specificity, Group B Streptococcus, Control Group, Medical and Health Sciences, and Streptococcal infections
Human calicivirus was the first recognized viral agent causing gastroenteritis in humans. Norovirus (NV) and Sapovirus (SV), two genera within the Caliciviridae family, cause epidemic and endemic acute gastroenteritis in children and... more
Human calicivirus was the first recognized viral agent causing gastroenteritis in humans. Norovirus (NV) and Sapovirus (SV), two genera within the Caliciviridae family, cause epidemic and endemic acute gastroenteritis in children and adults. The role of these viruses as a cause of sporadic acute gastroenteritis in young children requiring hospitalization is not well established. The aim of this study was to assess the prevalence and genetic diversity of caliciviruses among children hospitalized with symptoms of acute gastroenteritis. Stool samples were collected over 2 years from symptomatic children (N=1840) up to 5 years of age at three pediatric hospitals in the US. Overall, 156 (8.5%) samples were CV-positive, 131 (7.1%) confirmed by sequencing to be NV and 25 (1.4%) confirmed to be SV. Sequences of RT-PCR-amplified polymerase gene segments were analyzed using distance, maximum likelihood and parsimony algorithms. Phylogenetic analysis of 97 NV sequences showed that seven strains were in genogroup I, 86 strains were in genogroup II and four strains were not in genogroup I, II, or III, likely representing three new NV genogroups IV, VI and VII. Genogroup I and genogroup II strains were in 12 new genetic clusters, three in genogroup I and nine in genogroup II. Within genogroups I and II, most (98%) NV strains were in genetic clusters with no known prototype in GenBank. Phylogenetic analysis of 24 SV strains showed that half grouped with the London/92 strain in one genogroup and the remainder in three other proposed genogroups, one novel. In conclusion, NV and SV were frequent causes of hospitalization for acute gastroenteritis in young children and infecting strains were highly diverse, including newly recognized genogroups and genetic clusters within known genogroups.
Research Interests: Genetics, Acute gastroenteritis, Biology, Medicine, Genetic Diversity, and 15 moreMolecular Epidemiology, Phylogeny, Prospective studies, Humans, Norovirus, Maximum Likelihood, Gastroenteritis, Infant, Phylogenetic analysis, Newborn Infant, Prevalence, Longitudinal Studies, Genetic variation, Acute Disease, and Child preschool
Research Interests: Engineering, Biology, Bangladesh, Zoonoses, Medicine, and 14 moreBiological Sciences, Phylogeny, Humans, Animals, Poultry, Prevalence, Anti-Bacterial Agents, POULTRY DISEASES, Genotype, Microbial Sensitivity Tests, Base Sequence, Ribosomal DNA, Molecular Sequence Data, and Medical and Health Sciences
Research Interests: Microbiology, Medical Microbiology, Biology, Research, Adolescent, and 15 moreMedicine, Emerging Infectious Diseases, Humans, Child, United States, Salmonella Typhimurium, Clinical Sciences, Salmonella, Prevalence, Microbial Sensitivity Tests, Serotyping, Multiple Drug Resistance, Child preschool, Salmonella enterica, and Population surveillance
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Over a period of 6 months from January to June 2002, an unusual increase in the isolation of highly resistant Pseudomonas aeruginosa strains was observed in the various wards and intensive care units of a large general hospital in Johor... more
Over a period of 6 months from January to June 2002, an unusual increase in the isolation of highly resistant Pseudomonas aeruginosa strains was observed in the various wards and intensive care units of a large general hospital in Johor Bahru, Malaysia. An equal number of multidrug resistant (MDR) and drug-susceptible strains were collected randomly from swabs, respiratory specimens, urine, blood, cerebral spinal fluid, and central venous catheters to determine the clonality and genetic variation of the strains. Macrorestriction analysis by pulsed-field gel electrophoresis showed that the 19 MDR strains were genetically very homogenous; the majority showed the dominant profile S1 (n = 10), the rest very closely related profiles S1a (n = 1), S2 (n = 4), and S2a (n = 3), indicating the endemicity of these strains. In contrast, the 19 drug-sensitive strains isolated during the same time period were genetically more diverse, showing 17 pulsed-field profiles (F = 0.50-1.00), and probably...
Research Interests: Genetics, Malaysia, Biology, Medicine, Molecular Epidemiology, and 15 morePhylogeny, Humans, Multidrug Resistance, INTENSIVE CARE, Cluster Analysis, Ecological Succession, Intensive Care Unit, Distilled Water, Genetic variation, Pseudomonas Aeruginosa, Gel electrophoresis, Central Venous Catheter, cerebral spinal fluid, Nosocomial infection, and Cross Infection
Salmonella enterica serovar Paratyphi A is a causative agent of paratyphoid fever. The clinical syndrome caused by paratyphoid fever overlaps with other febrile illnesses and cannot be distinguished from typhoid fever. Conventional... more
Salmonella enterica serovar Paratyphi A is a causative agent of paratyphoid fever. The clinical syndrome caused by paratyphoid fever overlaps with other febrile illnesses and cannot be distinguished from typhoid fever. Conventional methods used for diagnosis are time consuming, costly, and labor-intensive. We evaluated the specificity, sensitivity, and application of a multiplex polymerase chain reaction (PCR) previously developed by the method (Ou, H.Y., Teh, C.S.J., Thong, K.L., et al., J. Mol. Diagn., 9, 624-630, 2007) using 6 S. Paratyphi A, 22 S. Typhi, and 85 other Salmonella serovars as well as 36 non-Salmonella strains. The detection limit of the multiplex PCR was 4 x 10(4) cfu ml(-1). In a blind test of the other 50 strains, this multiplex PCR correctly identified the only S. Paratyphi A in the panel of strains. The sensitivity of this PCR using spiked blood and stool samples was 1 x 10(5) cfu ml(-1) and 2 x 10(5) cfu ml(-1), respectively, but increased to 1 x 10(4) cfu ml(...
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The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na + -driven multidrug efflux pump-coding gene in the genome of... more
The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na + -driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223.
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ABSTRACTSalmonella entericaserovar Typhi is the causative agent of typhoid fever, which causes nearly 21.7 million illnesses and 217,000 deaths globally. Herein, we describe the whole-genome sequence of theSalmonellaTyphi strain ST0208,... more
ABSTRACTSalmonella entericaserovar Typhi is the causative agent of typhoid fever, which causes nearly 21.7 million illnesses and 217,000 deaths globally. Herein, we describe the whole-genome sequence of theSalmonellaTyphi strain ST0208, isolated from a sporadic case of typhoid fever in Kuala Lumpur, Malaysia. The whole-genome sequence and comparative genomics allow an in-depth understanding of the genetic diversity, and its link to pathogenicity and evolutionary dynamics, of this highly clonal pathogen that is endemic to Malaysia.
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ABSTRACTEscherichia coliis an important etiologic agent of lower respiratory tract infections (LRTI). Multidrug-resistantE. coliEC302/04 was isolated from a tracheal aspirate, and its genome sequence is expected to provide insights into... more
ABSTRACTEscherichia coliis an important etiologic agent of lower respiratory tract infections (LRTI). Multidrug-resistantE. coliEC302/04 was isolated from a tracheal aspirate, and its genome sequence is expected to provide insights into antimicrobial resistance as well as adaptive and virulence mechanisms ofE. coliinvolved in LRTI.
Research Interests: Microbiology, Bacteriology, Comparative Genomics, Biology, Biological Sciences, and 15 moreHumans, Escherichia coli, Multidrug Resistance, Pneumonia, Tetracycline, Antimicrobial resistance, Antibiotics, Science Technology, Genome sequence, Chloramphenicol, Escherichia Coli Infections, Multiple Drug Resistance, Molecular Sequence Data, Lower Respiratory Tract Infection, and Medical and Health Sciences
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Background: Differentiation of Salmonella enterica into its serogroups is important for epidemiological study. The objective of the study was to apply a multiplex PCR targeting serogroups A, B, C1, D, E and Vi-positive strains of... more
Background: Differentiation of Salmonella enterica into its serogroups is important for epidemiological study. The objective of the study was to apply a multiplex PCR targeting serogroups A, B, C1, D, E and Vi-positive strains of Salmonella enterica commonly found in Malaysia. A separate H-typing multiplex PCR which identified flagellar antigen “a”, “b ” or “d ” was also optimized to confirm clinical serotypes, S. Paratyphi A and S. Typhi. Methodology: Sixty-seven laboratory Salmonella enterica strains were tested. Six sets of primers targeting defined regions of the O antigen synthesis genes (rfb gene cluster) and Vi antigen gene (viaB) were selected and combined into a multiplex PCR for O-grouping. Four primers (H-for, Ha-rev, Hb-rev and Hd-rev) were used in the second step multiplex PCR for H-typing. The optimized mPCR assays were further evaluated with 58 blind-coded Salmonella strains. Results: The multiplex PCR results obtained showed 100 % concordance to the conventionally ty...
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Shigellosis is a foodborne illness caused by the genus Shigella and is an important global health issue. The development of effective techniques for rapid detection of this pathogen is essential for breaking the chain of transmission.... more
Shigellosis is a foodborne illness caused by the genus Shigella and is an important global health issue. The development of effective techniques for rapid detection of this pathogen is essential for breaking the chain of transmission. Therefore, we have developed a novel loop-mediated isothermal amplification (LAMP) assay targeting the invasion plasmid antigen H (ipaH) gene to rapidly detect Shigella species. This assay could be performed in 90 min at an optimal temperature of 64ºC, with endpoint results visualized directly. Notably, the method was found to be more sensitive than conventional PCR. Indeed, the detection limit for the LAMP assay on pure bacterial cultures was 5.9 x 10(5) CFU/ml, while PCR displayed a limit of 5.9 x 10(7) CFU/ml. In spiked lettuce samples, the sensitivity of the LAMP assay was 3.6 x 10(4) CFU/g, whereas PCR was 3.6 x 10(5) CFU/g. Overall, the assay accurately identified 32 Shigella spp. with one enteroinvasive Escherichia coli displaying positive react...
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variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures. Vibrio cholerae,... more
variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures. Vibrio cholerae, the causative agent of cholera, is endemic in many parts of the world, especially in countries that lack clean water supplies and adequate public health facilities (1). In Malaysia, cholera outbreaks caused by the El Tor O1 V. cholerae serogroup occur periodically, cases from the 0139 serogroup occur sporadically, and the non–O1/non–O139 V. cholerae serogroup has not been implicated in any major outbreak (2–4). Contaminated drinking water, cooked food, and raw or undercooked seafood served as vehicles of transmission in Malaysia (5). The Study In November 2009, a cholera outbreak occurred in Terengganu, Peninsular Malaysia. The outbreak began in the capital, Kuala Terengganu, and spread to several districts within a week. Approximately 400 persons wer...
The present study aims to develop a system which consists of four pairs of primers that specifically detects Salmonella spp., Salmonella serovar Typhi and Salmonella serovar Paratyphi A with an internal amplification control. The system,... more
The present study aims to develop a system which consists of four pairs of primers that specifically detects Salmonella spp., Salmonella serovar Typhi and Salmonella serovar Paratyphi A with an internal amplification control. The system, when applied in Polymerase Chain Reaction (PCR) under specific conditions, reaction mixture and cycling temperatures produced four bands; 784 bp, 496 bp, 332 bp and 187 bp. The DNA band 784 bp is present in all Salmonella spp., while the bands of 496 bp and 332 bp are only present in S. Paratyphi A and S. Typhi, respectively. An internal amplification control as indicated by the 187 bp shows the system is working in optimum condition in all the tests. This multiplex PCR was evaluated on 241 bacterial cultures and 691 naturally contaminated samples. Overall, this multiplex PCR detection system provides a single step for simultaneous detection of DNAs of Salmonella spp., S. Typhi and S. Paratyphi A.
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One hundred and fourteen strains of Pasteurella multocida were isolated from different domestic animals species (cattle, buffalo, sheep, goat, pig, rabbit, dog, cat), avian species (chicken, duck, turkey) and wild animals (deer, tiger,... more
One hundred and fourteen strains of Pasteurella multocida were isolated from different domestic animals species (cattle, buffalo, sheep, goat, pig, rabbit, dog, cat), avian species (chicken, duck, turkey) and wild animals (deer, tiger, orang utan, marmoset). The serogroups of P. multocida were determined by both conventional capsular serotyping and a multiplex PCR assay targeting specific capsular genes. Based on the conventional serotyping method, the 114 strains of P. multocida were subtyped into 55 species-specific (untypeable strains) P. multocida, 15 serogroup A, 23 serogroup B and 21 serogroup D. Based on the multiplex PCR assay on the specific capsular genes associated with each serogroup, the 114 strains were further divided to 22 species-specific P. multocida (KMT1 - 460 bp), 53 serogroup A (A - 1,044 bp), 33 serogroup B (B - 760 bp) and 6 serogroup D (D - 657 bp). No serogroup E (511 bp) or F (851 bp) was detected among the Malaysian P. multocida. PCR-based typing was more...
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Abstract. Salmonella enterica serovar Paratyphi B is known to cause either paratyphoid fever or gastroenteritis. Differentiation of Salmonella ser. Paratyphi B into biotype Java (d-tartrate fermenting, dT+) and biotype Paratyphi B... more
Abstract. Salmonella enterica serovar Paratyphi B is known to cause either paratyphoid fever or gastroenteritis. Differentiation of Salmonella ser. Paratyphi B into biotype Java (d-tartrate fermenting, dT+) and biotype Paratyphi B (d-tartrate non-fermenting, dT) is important for Salmonella epidemiology. This study applied a PCR approach to differentiate the two biotypes to augment the conventional biochemical method and to determine the antibiograms and genomic diversity of Malaysian S. Paratyphi B. Among 100 strains tested (clinical, 86; non-humans, 14), only two clinical strains were confirmed as biotype Paratyphi B as indicated by both lead acetate test and PCR. Antibiotic resistance rates were as follows: streptomycin 18%, sulphonamides 13%, ampicillin 10%, chloramphenicol 4%, tetracycline 3%, cefotaxime 2%, cefpodoxime 2%, ceftazidime 2%, gentamicin 1% and trimethoprim 1%. None showed resistance towards amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, nalidixic acid and t...
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Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae... more
Klebsiella pneumoniae is an opportunistic pathogen that is responsible for causing nosocomial and community-acquired infections. Despite its common presence in soil and aquatic environments, the virulence potential of K. pneumoniae isolates of environmental origin is largely unknown. Hence, in this study, K. pneumoniae isolated from the estuarine waters and sediments of the Matang mangrove estuary were screened for potential virulence characteristics: antibiotic susceptibility, morphotype on Congo red agar, biofilm formation, presence of exopolysaccharide and capsule, possession of virulence genes (fimH, magA, ugE, wabG and rmpA) and their genomic fingerprints. A total of 55 strains of K. pneumoniae were isolated from both human-distributed sites (located along Sangga Besar River) and control sites (located along Selinsing River) where less human activity was observed, indicated that K. pneumoniae is ubiquitous in the environment. However, the detection of potentially virulent strai...
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Molecular characterization of a total of 54 isolates of Salmonella typhi from Santiago, Chile, was performed by pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases: XbaI... more
Molecular characterization of a total of 54 isolates of Salmonella typhi from Santiago, Chile, was performed by pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases: XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3'), and SpeI (5'-ACTAGT-3'). Thirteen of the 54 isolates were obtained from environmental sources (sewage and river water), and the rest were isolates from clinical cases of typhoid fever.