Omid Zarei - Academia.edu (original) (raw)

Papers by Omid Zarei

مجله دانشکده پزشکی اصفهان, 2018

Background: Due to the increasing in antibiotic resistance in bacteria, especially the infections... more Background: Due to the increasing in antibiotic resistance in bacteria, especially the infections which their treatment is very difficult, there is a need for producing new drugs. The aim of this study was identification and purification of quorum sensing peptides causing apoptosis in Staphylococcus aureus as new treatment antibiotics. Methods: The supernatant from Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium were collected after centrifugation. Then, the supernatant was isolated from the specimens that had the greatest effect on the growth of bacteria. Liquid chromatography was used to purify it. In next step, for detection of protein concentration, Bradford test and for confirmation, two dimensional electrophoresis were used. Finally, to determine the antimicrobial activity of purified peptides, minimum inhibitory concentration (MIC) and minimum inhibitory concentration (MBC) of peptides were investigated. Findings: The obtained effective ingredient was a...

International Journal of Microbiology, 2021

Background. Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic food-bor... more Background. Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic food-borne pathogen. A total of 257 raw chicken meat samples were collected from different markets in Hamadan, west of Iran, from January 2016 to May 2017. Materials and Methods. The samples were cultured in selective and differential culture media, and the virulence genes of E. coli isolates were analyzed by PCR assay. The antibiotic resistance patterns of E. coli isolates were determined by the disk diffusion method. The genetic relatedness of the E. coli O157 isolates was analyzed by ERIC-PCR. Results. In total, 93 (36% ± 3.12) of the isolates were identified as E. coli in this study. Based on serological and microbiological tests, 36 (38.7% ± 9.9), 7 (7.5% ± 5.35), and 12 (12.9% ± 6.81) of the E. coli isolates were characterized as STEC, enteropathogenic E. coli (EPEC), and attaching and effacing E. coli (AEEC) strains, respectively. A high level of resistance to nalidixic acid (91.4% ± 5.7)...

Gene Reports, 2021

Abstract Introduction Escherichia coli is a commensal-pathogenic organism with a wide range of st... more Abstract Introduction Escherichia coli is a commensal-pathogenic organism with a wide range of strains. Several advanced molecular genomic-based technologies are used for detecting and identifying various strains of E. coli. Among them, the Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) technique is a fingerprint, fast and cost-effective method. The present study was aimed to determine the distribution of ERICs in E. coli strains isolated from different urine samples of patients. Methods A total of 92 UPEC isolates were obtained from inpatients and outpatients in Besat hospital and confirmed using standard microbiological, biochemical and molecular methods. The genetic relationship of the strains was investigated using ERIC method. Results Overall, 27 ERIC patterns were obtained that which 14 patterns were similar between different isolates (Common type) and 13 patterns were unique (Unique type). Conclusion ERIC-PCR is a simple, fast and low cost method to describe the genetic diversity of different E. coli strains including UPEC strains.

BMC Pharmacology and Toxicology, 2021

Background Acinetobacter baumannii is an opportunistic pathogen that can cause several kinds of n... more Background Acinetobacter baumannii is an opportunistic pathogen that can cause several kinds of nosocomial infections. Increasing antibiotic resistance as well as identifying genetic diversity and factors associated with pathogenicity and prevalence of this bacterium is important. The aim of this study was the investigation of molecular typing, biofilm production, and detection of carbapenemase genes in multidrug-resistant Acinetobacter baumannii isolated from different infection sites using ERIC-PCR in Iran. Methods Forty isolates of A. baumannii were obtained from various wards of the central hospital, in the west of Iran. Phenotypic identification and genetic diversity, biofilm production assay, and detection of Carbapenemase genes carried out. Results Tracheal samples 26 (61.9 %) are the most frequent isolates, and 95 % of isolates were identified as MDR. 32.5 % of all A. baumannii strains were capable to form a strong biofilm. It was founded that antimicrobial resistance patter...

Aim: This study determined the genes encoding the binding and receiving factors of iron and micro... more Aim: This study determined the genes encoding the binding and receiving factors of iron and microbial biofilm in E. coli strains isolated from mucosal samples of patients with colorectal cancer and inflammation of the colorectal compared to healthy people. Background: Colorectal cancer is one of the most important malignancies in recent years. Escherichia coli is the most important infectious agents associated with colorectal cancer that has numerous virulence factors such as iron uptake and adhesion factors included in the process of inflammation and colorectal cancer. Methods: Of the three healthy, inflammatory bowel diseases and colorectal cancer groups, 40 Escherichia coli strains isolated after confirmation by biochemical and molecular methods. After determining the isolates phylogroups, the frequency of genes was measured by PCR method. The biofilm formation of isolates was performed using Crystal Violet method. Results: In the determination of the bacteria phylogroups, the co...

International Journal of Microbiology, 2020

Aim. Klebsiella pneumoniae is one of the most important causes of nosocomial infections, includin... more Aim. Klebsiella pneumoniae is one of the most important causes of nosocomial infections, including pneumonia, sepsis, and urinary tract infection. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) technique is a quick, reliable, and cost-effective method for molecular typing of Enterobacteriaceae family members. This study aimed to detect genetic relatedness among K. pneumoniae isolates from hospitals in Hamadan city, using ERIC-PCR technique. Materials and Methods. A total of 72 K. pneumoniae isolates were collected from patients admitted to Besat and Sina hospitals. After detection and confirmation of K. pneumonia isolates by chemical and conventional microbiological methods, DNAs were extracted after 24 hours of incubation at 37°C, using the boiling method. ERIC-PCR technique was carried out, and the ERIC patterns were analyzed by online data analysis service (inslico.ehu.es). ERIC profiles were compared using Dice method and clustered by UPGMA ...

Infection and Drug Resistance, 2020

Infectious Disorders - Drug Targets, 2019

Background: Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacterium an... more Background: Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacterium and an opportunistic pathogen in humans and animals. The present study was carried out in order to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment. Material and Methods: A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, west of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exo A, exo S, exo U, and alg D using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method. Results: The results showed the prevalence of exo A 33 (56.9%), exo S 21 (36.20%), exo U 37 (63.8%), and alg D 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exo S 25 (43.1%), exo U 40(6...

Human Vaccines & Immunotherapeutics, 2019

Recent Patents on Anti-Infective Drug Discovery, 2019

Introduction: Antibiotic resistance and extensive use of antibiotics is one of the major causes o... more Introduction: Antibiotic resistance and extensive use of antibiotics is one of the major causes of failure in antibiotic treatment. The purpose of this study was to investigate antibiotic resistance patterns and to identify resistance genes of quinolones and colistin in Escherichia coli. There are very few patents on E. coli isolated from colorectal cancer. So, this study demonstrated that some bacteria resistant to ciprofloxacin are not present resistance genes. As well as, new patterns for E. coli are presented for samples of patients with colorectal cancer. Materials and Methods: Of the three healthy, inflammatory bowel diseases (IBD) and colorectal cancer groups, 40 E. coli strains isolated after confirmation by biochemical and molecular methods. The susceptibility of isolates to antibiotics was investigated using disk diffusion test. After deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR) was used to identify genes encoding resistance to ciprofloxacin (qnr...

Objective: Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic foodborne... more Objective: Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic foodborne pathogen. A total of 257 raw chicken meat samples were collected from different markets in Hamadan, west of Iran, from January 2016 to May 2017. The samples were cultured on selective and differential culture media and the virulence genes of E. coli isolates were analyzed by PCR assay. The antibiotic resistance patterns of E. coli isolates were determined by the disk diffusion method. The genetic relatedness of the E. coli O157 isolates was analyzed by ERIC-PCR. Results: In total, 93 (36%) of the isolates were identified as E. coli in this study. Based on serological and microbiological tests, 36 (38.7%), 7 (7.5%), and 12 (12.9%) of the E. coli isolates were characterized as STEC, Enteropathogenic E. coli (EPEC), and attaching and effacing E. coli (AEEC) strains, respectively. A high level of resistance to nalidixic acid (91.4%), tetracycline (89.8), ampicillin (82.8%), and sulfametoxaz...

Background: Streptococcus pneumonia is a major cause of childhood morbidity and mortality worldwi... more Background: Streptococcus pneumonia is a major cause of childhood morbidity and mortality worldwide. Several studies have explored the nasopharyngeal carriage of S. pneumonia in Iran. This meta-analysis is aimed at exploring the overall prevalence of nasopharyngeal carriage of S. pneumonia among healthy children and its resistance to antibiotics. Method: We have systematically reviewed published studies from international databases (PubMed, Web of Science, and Scopus) and national databases (Iranmedex, Magiran, Medlib, SID and Irandoc) and reference lists of articles published up to May 2015. Only cross-sectional studies supported with sensitivity test on samples collected from nasopharyngeal area were included and heterogeneity was assessed using Q-test and I2 test statistic. Publication bias was explored using the Egger's and Begg's tests and the funnel plot. The overall prevalence of analyzed data were reported with 95% confidence intervals (CI) using the random-effects m...

Thermostable alkaline α-amylase producing bacterium Bacillus cereus strain isolated from Cuddalor... more Thermostable alkaline α-amylase producing bacterium Bacillus cereus strain isolated from Cuddalore harbour waters grew maximally in both shake flask and fermentor, and produced α-amylase at 35°C, pH 7.5 and 1.0% of substrate concentrations. α-Amylase activity was maximum at 65°C, pH 8.0, 89% of its activity was sustained even at pH 11.0. Added with MnCl2, α-amylase activity showed 4% increase but it was inhibited by EDTA. The molecular weight of the purified α-amylase is 42 kDa.