- Iran University of Medical Sciences, Medical Mocrobiology, Department Memberadd
- I am Ebrahim Kouhsari, Ph.D in Medical Bacteriology. My research interests working on anaerobic infections bacteria, ... moreI am Ebrahim Kouhsari, Ph.D in Medical Bacteriology. My research interests working on anaerobic infections bacteria, and nosocomial infections. I exprienced in Molecular diagnostics infections, antimicrobial resistance testing , and molecular typing on Clostridium difficile infection, Bacteriodes fragilis, and ..... Also, i interest to working on fungal infections and writing review articles (narative or systematic review). My email: Ekouhsari1987@gmail.com Bestedit
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BACKGROUND Diarrhea remains a major threat to children in low- and middle-income countries, which is the second cause of death among children in the world. The aim of the present study was to develop and evaluate a multiplex-PCR assay for... more
BACKGROUND Diarrhea remains a major threat to children in low- and middle-income countries, which is the second cause of death among children in the world. The aim of the present study was to develop and evaluate a multiplex-PCR assay for direct detection of common bacterial enteropathogens in fecal specimens. METHODS One hundred and three stool specimens were collected from children under 5 years of age with gastroenteritis during a six-month period in Ilam, Iran. The multiplex PCR assay simultaneously detected Shigella spp., Campylobacter jejuni, Enteropathogenic Escherichia coli (EPEC), Enterotoxigenic Escherichia coli (ETEC), and Salmonella enterica in stool samples. RESULTS Our results demonstrated that the prevalence of Shigella spp. Campylobacter jejuni, EPEC, ETEC, and Salmonella enterica were 21.35%, 10.67%, 1.94%, 0.97% and 0%, respectively. In addition, Shigella spp. with Campylobacter jejuni and EPEC with Campylobacter jejuni coinfection were observed in sample 11 (10.67%). The analytical sensitivity of the multiplex PCR assay was estimated to be 0.01 ng/µL of genomic DNA from culture. The analytical specificity was determined to be 100% by using common and standard enteropathogenic bacterial strains. CONCLUSIONS The molecular method developed in the study was rapid, sensitive, and specific for detection of common bacterial enteropathogens.
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Esophageal cancer (EC) is categorized histologically to two common groups; adenocarcinomas and squamous cell carcinomas, with high incidence and mortality worldwide. Esophageal squamous cell carcinoma (ESCC) is the most prevalent (more... more
Esophageal cancer (EC) is categorized histologically to two common groups; adenocarcinomas and squamous cell carcinomas, with high incidence and mortality worldwide. Esophageal squamous cell carcinoma (ESCC) is the most prevalent (more than 90%) form of all EC cases in Golestan province. Golestan province, as the high-risk province for ESCC, is located in the eastern part of the Caspian littoral area of Iran, although in the last decades, the occurrence rates have decreased in this area. Tobacco smoking, opium consumption, low oral hygiene, drinking hot liquids, insufficient intake of fresh fruits and vegetables, and poor socioeconomic status increase the risk of ESCC in Golestan, although exposure to infections and toxic chemical compounds are also reported. Here, we summarize the previous epidemiological studies from 1970 to 2019 that have investigated the risk factors involved in ESCC in this high-risk area. More prospective cohort studies are required to assess the risk factors,...
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The prevalence of carbapenemase-producing Enterobacteriaceae has increased dramatically over the past decade. Identification of these bacteria because of its variation in minimum inhibitory concentration for carbapenem resistance is... more
The prevalence of carbapenemase-producing Enterobacteriaceae has increased dramatically over the past decade. Identification of these bacteria because of its variation in minimum inhibitory concentration for carbapenem resistance is important. Therefore, identification of the bacteria in the clinical microbiology laboratory is a major matter for the selection and implementation of infection control measures and appropriate treatment plan. The screening of carbapenemase-producing bacteria could be done with different phenotypic, biochemical and molecular methods; however, each of these methods has its own advantages and disadvantages. The aim of this study is to investigate and introduction of common available methods to detect carbapenemase.
Research Interests: Microbiology and Medicine
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Background Mycobacterium tuberculosis (MTB) is responsible for tuberculosis; that continues to be a public health threat across the globe. Furthermore, increasing heteroresistance (HR)-the presence of resistant and susceptible isolates... more
Background Mycobacterium tuberculosis (MTB) is responsible for tuberculosis; that continues to be a public health threat across the globe. Furthermore, increasing heteroresistance (HR)-the presence of resistant and susceptible isolates among MTB strains- has been reported from around the world. This phenomenon can lead to full resistance development and treatment failure. Methods We systematically searched the relevant studies in PubMed, Scopus, and Embase (Until October 21, 2020). The study outcomes revealed the weighted pooled prevalence of antibiotic HR in MTB isolates with subgroup analysis by year, quality of study, and heteroresistance detection method. Results A total of 38 studies which had investigated MTB isolates were included in the meta-analysis. Geographically, the highest number of studies were reported from Asia (n = 24), followed by Africa (n = 5). Nineteen studies reported HR to isoniazid, with a weighted pooled prevalence of 5% (95% CI 0–12) among 11,761 MTB i...
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Background Clostridioides (Clostridium) difficile is an important pathogen of healthcare- associated diarrhea, however, an increase in the occurrence of C. difficile infection (CDI) outside hospital settings has been reported. The... more
Background Clostridioides (Clostridium) difficile is an important pathogen of healthcare- associated diarrhea, however, an increase in the occurrence of C. difficile infection (CDI) outside hospital settings has been reported. The accumulation of antimicrobial resistance in C. difficile can increase the risk of CDI development and/or its spread. The limited number of antimicrobials for the treatment of CDI is matter of some concern. Objectives In order to summarize the data on antimicrobial resistance to C. difficile derived from humans, a systematic review and meta-analysis were performed. Methods We searched five bibliographic databases: (MEDLINE [PubMed], Scopus, Embase, Cochrane Library and Web of Science) for studies that focused on antimicrobial susceptibility testing in C. difficile and were published between 1992 and 2019. The weighted pooled resistance (WPR) for each antimicrobial agent was calculated using a random- effects model. Results A total of 111 studies were includ...
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Some fungal species of the genera Aspergillus, Penicillium, and Fusarium secretes toxic metabolites known as mycotoxins, have become a global concern that is toxic to different species of animals and humans. Biological mycotoxins... more
Some fungal species of the genera Aspergillus, Penicillium, and Fusarium secretes toxic metabolites known as mycotoxins, have become a global concern that is toxic to different species of animals and humans. Biological mycotoxins detoxification has been studied by researchers around the world as a new strategy for mycotoxin removal. Bacteria, fungi, yeast, molds, and protozoa are the main living organisms appropriate for the mycotoxin detoxification. Enzymatic and degradation sorptions are the main mechanisms involved in microbiological detoxification of mycotoxins. Regardless of the method used, proper management tools that consist of before-harvest prevention and after-harvest detoxification are required. Here, in this review, we focus on the microbiological detoxification and mechanisms involved in the decontamination of mycotoxins.
Research Interests: Medicine and Minocycline
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Sigma factors are proteins that regulate transcription in bacteria. Sigma factors can be activated in response to different environmental conditions. The rpoS (RNA polymerase, sigma S) gene encodes sigma-38 (σ38, or RpoS), a 37.8 kDa... more
Sigma factors are proteins that regulate transcription in bacteria. Sigma factors can be activated in response to different environmental conditions. The rpoS (RNA polymerase, sigma S) gene encodes sigma-38 (σ38, or RpoS), a 37.8 kDa protein in Pseudomonas aeruginosa (P. aeruginosa) strains. RpoS is a central regulator of the general stress response and operates in both retroactive and proactive manners; not only does it allow the cell to survive environmental challenges; it also prepares the cell for subsequent stresses (cross-protection). The significance of RpoS for stress resistance and protein expression in stationary-phase P. aeruginosa cells was assessed. The goal of the current study was to characterize RpoS of P. aeruginosa PAO1 using bioinformatics tools. The results showed that RpoS is an unstable protein that belongs to the sigma-70 factor family. Secondary structure analysis predicted that random coil is the predominant structure followed by extended alpha helix. The th...
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Background: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. Objective: We aimed in this study to investigate the role of AcrAB,... more
Background: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. Objective: We aimed in this study to investigate the role of AcrAB, qepA efflux pump, and AAC(6′)-Ib-cr enzyme in ciprofloxacin resistance and to detect the RAPD-PCR fingerprint of K. pneumoniae isolates. Methods: In total, 117 K. pneumoniae isolates were collected from hospitalized patients in three hospitals in Tehran, Iran from August 2013 to March 2014. Antimicrobial susceptibility tests were performed by the disk diffusion method. Molecular identification and expression level of encoding quinolone resistance genes, acrA, acrB, qepA, and aac(6')-Ib-cr, was per-formed by PCR and real-time PCR assays, respectively. All the K. pneumoniae isolates containing these genes was used simultaneously for RAPD-PCR typing. Results: Colistin and carbapenems were the most efficient antibiotics against the clinical isolates...
Research Interests: Microbiology, Medical Microbiology, Transmission Electron Microscopy, Dendrimers, Humans, and 13 moreEscherichia coli, Mice, Animals, Staphylococcus aureus, Pseudomonas aeruginosa, Gram Positive Bacteria, Clinical Sciences, Gram-negative bacteria, Anti-Bacterial Agents, Fourier transform infrared spectroscopy, Microbial Sensitivity Tests, Pseudomonas Aeruginosa, and Klebsiella pneumoniae
Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against... more
Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B1, B2, G1 and G2 fractions by more than 99%. Moreover, LAB metabolites reduce...