Prevalence of Enteropathogenic and Shiga Toxin-producing Escherichia coli Among Children With and Without Diarrhoea in Iran

The aim of the study was to determine the rates of detection of enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains among children in two randomly-selected populations in Iran. In total, 1,292 randomly-selected faecal samples from children aged less than 10 years were screened for EPEC and STEC. Of the 1,292 cases participated in the study, 184 had diarrhoea, and 1,108 were healthy/asymptomatic children. The conventional culture method and slide agglutination with 12 different commercial EPEC antisera were used for the detection of EPEC. The colony sweep polymyxin- B extraction method, non-sorbitol fermentation (NSF) phenotype, and slide agglutination with O157: H7 antisera were used for the screening and detection of STEC. Of EPEC belonging to 11 different serogroups, O111 and O127 were most commonly found in 36.4% of the diarrhoeal cases and 7.2% of the asymptomatic children. A significant association (p<0.05) was found between isolation of EPEC and diarrhoea. 8.7% of the diarrhoeal cases and 2% of children without diarrhoea were infected with STEC, but none of the isolates belonged to the O157:H7 serotype. A significant association (p<0.05) was found between STEC and diarrhoeal cases. Based on these findings, it can be concluded that different EPEC serogroups may be agents of endemic infantile diarrhoea, and STEC strains are an important enteropathogen among young children

Prevalence of Enteropathogenic and Shiga Toxin-producing Escherichia coli Among Children With and Without Diarrhoea in Iran

The aim of the study was to determine the rates of detection of enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains among children in two randomly-selected populations in Iran. In total, 1,292 randomly-selected faecal samples from children aged less than 10 years were screened for EPEC and STEC. Of the 1,292 cases participated in the study, 184 had diarrhoea, and 1,108 were healthy/asymptomatic children. The conventional culture method and slide agglutination with 12 different commercial EPEC antisera were used for the detection of EPEC. The colony sweep polymyxin- B extraction method, non-sorbitol fermentation (NSF) phenotype, and slide agglutination with O157: H7 antisera were used for the screening and detection of STEC. Of EPEC belonging to 11 different serogroups, O111 and O127 were most commonly found in 36.4% of the diarrhoeal cases and 7.2% of the asymptomatic children. A significant association (p<0.05) was found between isolation of EPEC and diarrhoea. 8.7% of the diarrhoeal cases and 2% of children without diarrhoea were infected with STEC, but none of the isolates belonged to the O157:H7 serotype. A significant association (p<0.05) was found between STEC and diarrhoeal cases. Based on these findings, it can be concluded that different EPEC serogroups may be agents of endemic infantile diarrhoea, and STEC strains are an important enteropathogen among young children

Determination of Asymptomatic Chlamydia Trachomatis Infections by Omp1 Gene Based -PCR

Objective: The objective of this research was to determine the prevalenceof genital C. trachomatis infection in asymptomatic women by using highlysensitive nested-polymerase chain reaction (PCR) in urine sample.Materials and Methods: One hundred-forty asymptomatic women wererandomly selected from those who attended gynecology out patient departmentof Hazraat e Rasool Hospital in Tehran. First catch urine specimen were collectedfrom all the participants. DNA extraction was performed by means of HighPure PCR Template Preparation Kit (HPPTP) according to the manufacture’sinstructions. Extracted DNA was tested by omp1 gene based nested-PCR,using sets of primers to amplify C. trachomatis omp1 gene. Visualizationof a 1027 bp fragment from omp1 gene in agarose gel electrophoresis wasconsidered as a positive result.Results: In total, 140 urines were tested for determination of C. trachomatisinfection. C. trachomatis omp-1 was detected in 22.1% of cases (31/140). Theoverall prevalence rates of C. trachomatis in the urine sample as determined byomp1 based nested-PCR were 4.3% in group I (age, <25 years), 12.1% in groupII (age, 25-34 years), 5.0% in group III (age, 35-44 years) and 0.7% in group IV(>44 years). The highest prevalence of C. trachomatis infection (12.1%) wasseen in women aged 25-34 years. This finding was not statistically significant(p=0.710). Also, there was not relation between C. trachomatis infection andsome probable risk factors such as young age (<25 years), STD history andmissing use of barrier contraceptive in this study.Conclusion: The prevalence of C.trachomatis infection in the women notseeking health care warrants more comprehensive study using high sensitiveomp1 based nested- PCR to identify and treat a large number of infectedwomen in Iran

Virulence factors, antimicrobial susceptibility and molecular characterization of Streptococcus agalactiae isolated from pregnant women

Forty-one Streptococcus agalactiae isolates collected from pregnant women at 35–37 weeks of gestation were analysed for their capsular types, antimicrobial resistance determinants, distribution of virulence factors and genetic relatedness using PCR and multiplex PCR. Capsular type III was predominant (65.8%), followed by capsular type II (14.6%), Ib (7.3%), and V(4.9%). All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline, erythromycin and clindamycin were found in 97.6%, 24.4%, and 14.6% of isolates, respectively. The most common antimicrobial resistance gene was tetM found in 97.6% of the isolates followed by ermTR and ermB found in 12% and 7.3% of isolates, respectively. The most common virulence gene was hly (100%), followed by scpB (97.6%), bca (97.6%), rib (53.65%) and bac (4.9%). The insertion sequence IS1548 was found in 63.4% of isolates. By multi locus variable number of tandem repeat analysis (MLVA) typing, 30 different allelic profiles or MLVA types (MTs) were identified. The most frequent was the MT1 (5/41, 12.2%) and followed by MT2 (4/41, 9.75%). Our data revealed that population structure of these isolates is highly diverse and indicates different MLVA types