High Frequency of Diarrheagenic Escherichia coli in HIV-Infected Patients and Patients with Thalassemia in Kerman, Iran

Frequency of five Escherichia Coli pathotypes in Iranian adults and children with acute diarrhea

Background

Knowledge about the distribution of Escherichia Coli (E. coli) pathotypes in Iran is limited. This nation-wide survey aims to provide a comprehensive description of the distribution of five pathogenic E. coli in Iran.

Methods

Stool samples were collected from 1,306 acute diarrhea cases from 15 provinces (2013–2014). E. coli-positive cultures underwent PCR testing for the detection of STEC, ETEC, EPEC, EAEC, and EIEC pathotypes. Pathotype frequency by province, age-group, and season was estimated.

Results

979 diarrhea samples (75.0%) were culture-positive for E. coli (95% CI: 72.6, 77.3%), and 659 (50.5%) were pathogenic E. coli (95% CI: 47.8, 53.2%). STEC was the most frequent pathotype (35.4%). ETEC (14.0%) and EPEC (13.1%) were the second and the third most frequent pathotypes, respectively. EAEC (4.3%) and EIEC (0.3%) were not highly prevalent. Fars (88.7%) and Khorasan-e-Razavi (34.8%) provinces had the highest and lowest frequencies, respectively. E. coli pathotypes were more frequent in warmer than cooler seasons, showed the highest frequency among children under five years of age (73%), and had no significant association with participants’ gender.

Conclusions

Diarrheagenic E. coli may be an important cause of acute diarrhea in adults and children in Iran. STEC and ETEC seem to be widespread in the country with a peak in warmer seasons, impacting the recommended use of seasonal STEC and ETEC vaccines, especially in high-risk groups. Monitoring the incidence of E. coli pathotypes, serotypes, and antibiotic resistance over time is highly recommended for evaluation of interventions.

Prevalence of cigarette smoking among college students in Iran: An updated systematic review and meta-analysis of observational studies

Background: Cigarette smoking is known as a gateway drug for illicit drug use in youth. The objective of this study is to assess the prevalence of cigarette smoking in the college students in Iran.

Methods: We searched electronic databases including Scopus, Medline/PubMed, Google Scholar and Web of Science, and national databases such as Magiran, Scientific Information Database, Iranmedex, Medlib, Irandoc, and IranPsych from 1946 to 21st July 2018 without any language restriction using a proper search strategy. We used a random effect model to calculate the pooled prevalence of cigarette smoking in college students in Iran. Chi-square test and I2 index were used to evaluate the heterogeneity between the studies. We used the meta-regression and subgroup analysis to assess the potential source of heterogeneity. Stata software, version 11 (StataCorp, TX) was used for all statistical analysis.

Results: We included 60 eligible articles in our study. The pooled prevalence of cigarette smoking at least once in the lifetime was 19% (95%CI: 17-22). The I2 index indicated considerable between-study heterogeneity (I2 =98%, p<0.001). The pooled prevalence of cigarette smoking at least once in the lifetime in males and females was 28% (95% CI: 23-34) and 9% (95% CI: 6-13), respectively. In multivariable meta-regression, a significant association was shown between the year of study (β=-13.1, p=0.011) and sampling method (β=-12.8 p=0.017) and daily use in the last month.

Conclusions: Increasing prevalence of smoking among Iranian university students is an important health priority. Increasing preventive and health education programs are recommended.

Comparison of Multiplex Gastrointestinal Pathogen Panel and Conventional Stool Testing for Evaluation of Patients With HIV Infection

BACKGROUND

Gastrointestinal pathogen panels (GPPs) are increasingly used to identify stool pathogens, but their impact in people with HIV (PWH) is unknown. We performed a retrospective cohort study comparing GPP and conventional stool evaluation in PWH.

METHODS

We included all PWH who underwent GPP (Biofire Diagnostics; implemented September 15, 2015) or conventional testing, including stool culture, Clostridium difficile polymerase chain reaction testing, fluorescent smears for Cryptosporidium or Giardia, and ova and parasite exams (O&P) from 2013 to 2017. A total of 1941 specimens were tested, with 169 positive specimens detected in 144 patients. We compared result turnaround time, pathogen co-infection, antibiotic treatment, and treatment outcomes between positive specimens detected by conventional testing vs GPP.

RESULTS

Overall, 124 patient samples tested positive by GPP, compared with 45 patient specimens by conventional testing. The GPP group demonstrated a higher co-infection rate (48.4% vs 13.3%; P < .001) and quicker turnaround time (23.4 vs 71.4 hours; P < .001). The GPP identified 29 potential viral infections that were undetectable by conventional stool tests. Unnecessary anti-infective therapy was avoided in 9 of 11 exclusively viral infections. Exclusively nonpathogenic parasites (n = 13) were detected by conventional stool tests, the majority of which were treated with metronidazole. There were no significant differences in clinical outcomes between groups.

CONCLUSIONS

In PWH, GPP implementation improved antibiotic stewardship through shorter turnaround times and detection of enteric viral pathogens.

An overview of diarrheagenic Escherichia coli in Iran: A systematic review and meta-analysis

BACKGROUND

Diarrheagenic Escherichia coli (DEC) is a common enteric pathogen that causes a wide spectrum of gastrointestinal infections, particularly in developing countries. This is a systematic review and meta-analysis to determine the prevalence of DEC in various geographical regions in Iran.

MATERIALS AND METHODS

English (PubMed, Web of Science, Scopus, Embase, Cochrane Library, and Google Scholar) and Persian (IranMedex, SID, Magiran, and Iran Doc) databases were comprehensively searched from January 1990 to April 2017. Study selection and data extraction were performed by two independent reviewers. After assessing heterogeneity among studies, a random effects model was applied to estimate pooled prevalence. Data analyses were done with the Stata software (version 12.0). This meta-analysis was registered with PROSPERO, number CRD42017070411.

RESULTS

A total of 73 studies with 18068 isolates were eligible for inclusion within the meta-analysis. The results of random effects model showed that the most prevalent DEC pathotypes were enterotoxigenic E. coli (ETEC) (16%; 95% confidence interval [CI]: 11%-23%), enteroaggregative E. coli (11%; 95% CI: 8%-15%), atypical enteropathogenic E. coli (EPEC) (11%; 95% CI: 8%-14%), Shiga toxin-producing E. coli (9%; 95% CI: 6%-13%), diffuse adherent E. coli (6%; 95% CI: 6%-12%), enteroinvasive E. coli (4%; 95% CI: 2%-6%), and typical EPEC (3%; 95% CI: 1%-5%).

CONCLUSION

This study showed that DEC infections in the Iranian population have low frequency. Our data suggest that the ETEC pathotype can be regarded as one of the most important etiological agents of diarrhea in this country. However, the prevalence of DEC pathotypes is diverse in different regions of Iran.

Serogroups, subtypes and virulence factors of shiga toxin-producing Escherichia coli isolated from human, calves and goats in Kerman, Iran

AIM

The present study was conducted to detect the occurrence, serogroups, virulence genes and phylogenetic relationship of shiga toxin-producing Escherichia coli (STEC) in human, clave and goat in Kerman (southeast of Iran).

BACKGROUND

STEC have emerged as the important foodborne zoonotic pathogens causing human gastrointestinal disease and confirming the risk to public health.

METHODS

A total of 671 fecal samples were collected from diarrheic patients (n=395) and healthy calves (n=156) and goats (n=120) and screened for the presence of stx gene. Furthermore, the prevalence of stx1 and stx2 variants, serotypes (O157, O145, O103, O26, O111, O91, O128, and O45), phylogenetic groups and the presence of ehxA, eae, hylA, iha and saa virulence genes were studied.

RESULTS

Prevalence of STEC in human diarrheic isolates was 1.3% (5 isolates), in claves was 26.3% (41 isolates) and in goats was 27.5% (33 isolates). stx1 gene was the most prevalent variant and detected in 75 isolates. Furthermore, stx1c was the most predominant stx subtype, found in 56 isolates. The ehxA identified in 36 (45.6%) isolates, followed by iha 5 (6.3%), eaeA 4 (5.1%), hlyA 2 (2.5%) and saa 2 (2.5%). Most of the isolates belonged to phylogroup B1. Only two O26 and one O91 isolates were detected in our study.

CONCLUSION

Our results show that STEC strains were widespread among healthy domestic animals in the southeast of Iran.

Phylogenetic background of enterotoxigenic and enteroinvasive Escherichia coli from patients with diarrhea in Sirjan, Iran

BACKGROUND AND OBJECTIVES

Diarrheagenic Escherichia coli (DEC) strains are a major cause of intestinal syndromes in the developing countries. The aim of this study was to determine the prevalence of enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC) in relation to phylogenetic background from patients with diarrhea.

MATERIALS AND METHODS

A total of 110 E. coli isolates were obtained from diarrhea patients in Sirjan, southeast of Iran. The E. coli isolates were confirmed using biochemical and bacteriological tests. DNA of E. coli isolates was extracted by boiling method and checked for existence of ETEC (LT and ST genes) and EIEC (ipaH gene) pathotypes and also characterize the phylogenetic groups on the basis of presence or absence of the chuA, yjaA genes and an anonymous DNA fragment, TspE4. C2 by multiplex PCR.

RESULTS

Out of 110 E. coli isolates, 32 (29.09%) were positive for ETEC (LT and ST genes) and 6 (5.45%) possessed EIEC (ipaH gene) pathotypes. Isolates fall into four phylogenetic groups: A (39.09%), B1 (20%), B2 (15.45%) and D (25.45%). Phylotyping of isolates of DEC indicated they were distributed in four phylogenetic groups including A (12 isolates), B1 (7), B2 (9) and D (10).

CONCLUSION

In this study, the DEC isolates were segregated into different phylogenetic groups. The majority of isolates belonged to phylo-groups A and D.