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

Prevalence of common diarrheagenic enterobacteriaceae in Iran (2000-2023): a systematic review and meta-analysis

OBJECTIVE

Bacterial gastroenteritis is a significant public health concern, capable of causing severe infections. Among the various pathogens involved, those belonging to the Enterobacteriaceae family are the most frequently isolated and associated with gastrointestinal disorders. This study aimed to investigate the prevalence of common diarrheagenic Enterobacteriaceae in Iran over the past two decades, from 2000 to 2023.

METHODS

A comprehensive systematic search was conducted across multiple databases, including EMBASE, HINARI, MEDLINE, PubMed, Google Scholar, and the Cochrane Library. The focus was on observational published studies reporting the prevalence of diarrheagenic Enterobacteriaceae in Iran during 2000 and 2023. The criteria did not restrict patient demographics such as age, gender, health conditions, or occupation. This meta-analysis employed a 95% confidence interval (CI) for analysis. Evidence of heterogeneity was determined using an I² value greater than 50%. To explore potential sources of heterogeneity, subgroup analysis and meta-regression analysis were performed. Statistical analyses were executed using R version 4.3.2 along with the meta package. A p-value less than 0.05 was considered statistically significant.

RESULTS

Out of 3,701 papers reviewed, 56 studies met the inclusion criteria and were analyzed. The overall pooled prevalence of diarrheagenic Enterobacteriaceae species from 2000 to 2023 was 14.0% (95% CI: 0.11-0.17). Subgroup analysis revealed Shigella spp. had the highest prevalence at 18.0% (95% CI: 0.13-0.24; I²=99%), followed by diarrheagenic Escherichia coli at 11.0% (95% CI: 0.09-0.15; I²=97%), Salmonella spp. at 9.0% (95% CI: 0.05-0.17; I²=99%), and Yersinia spp. at 2.0% (95% CI: 0.00-0.10; I²=94%). Prevalence trends showed Shigella spp. increasing from 4% (95% CI: 0.03-0.08) in 2000-2004 to 36% (95% CI: 0.20-0.55) in 2021-2023. Diarrheagenic E. coli (DEC) showed no clear pattern, ranging from 5% (95% CI: 0.01-0.24) to 17% (95% CI: 0.07-0.36). Salmonella spp. exhibited more significant fluctuations, rising from 6% (95% CI) in both 2000-2004 and 2005-2008 periods to 20% (95% CI: 0.03-0.66) in 2009-2012 and 30% (95% CI: 0.11-0.60) in 2017-2020. Yersinia spp. was only determined in 2000-2004 with a pool prevalence of 12% (95% CI: 0.00-0.91). Sub-species analysis revealed Shigella sonnei was the most prevalent species among Shigella spp. in Iran, accounting for 42% of cases (95% CI: 0.33-0.52). Regarding DEC species, Enteroaggregative E. coli (EAEC) and Enterotpathogenic E. coli (EPEC) had the highest rate at 15% (95% CI). Furthermore, a pool prevalence of 2% (95% CI: 0.00-0.89) was reported for Yersinia enterocolitica among diarrheagenic Enterobacteriaceae in Iran.

CONCLUSION

This meta-analysis provides valuable insights into the prevalence of diarrheagenic Enterobacteriaceae in Iran over the past two decades. The findings highlight the significant impact of these pathogens on public health, with Shigella spp. showing the highest prevalence and increasing trends. Further research should investigate the factors contributing to the prevalence of diarrheagenic Enterobacteriaceae, including genetic diversity of diarrheagenic Enterobacteriaceae isolates, molecular mechanisms underlying the virulence of these pathogens, or antibiotic resistance patterns.

Can Wastewater Surveillance Enhance Genomic Tracking of Climate-Driven Pathogens?

Climate change heightens the threat of infectious diseases in Europe, necessitating innovative surveillance methods. Based on 390 scientific papers, for the first time, this review associates climate-related pathogens, data related to their presence in wastewater, and associated available genomic detection methods. This deep analysis reveals a wide range of pathogens that can be tracked through methods such as quantitative and digital PCR, as well as genomic pathogen enrichment in combination with sequencing and metagenomics. Nevertheless, significant gaps remain in the development of methods, particularly for vector-borne pathogens, and in their general harmonization relating to performance criteria. By offering an overview of recent advancements while identifying critical gaps, we advocate for collaborative research and validation to integrate detection techniques into surveillance frameworks. This will enhance public health resilience against emerging infectious diseases driven by climate change.

Sequence-subtype association of multi-drug-resistant diarrheagenic Escherichia coli

Background and Objectives

Multi-drug-resistant pathogens pose a significant threat as they can rapidly spread, leading to severe healthcare-associated invasive infections. In developing countries, diarrheagenic Escherichia coli (DEC) is a major bacterial pathogen responsible for causing diarrhea. However, the outbreak of resistant strains has made the treatment of DEC infections much more challenging. This study aimed to investigate the relationship between antibiotic resistance genes and other virulence categories in E. coli strains that cause diarrhea, particularly DEC.

Materials and Methods

The phylogenetic grouping was defined using PCR and multi-locus sequence type (MLST) methods.

Results

Among the isolates analyzed, 14 were identified as resistant and were classified into eight distinct sequence types: ST3, ST53, ST77, ST483, ST512, ST636, ST833, and ST774, indicating genetic diversity among the resistant strains. Certain sequence types, notably ST512 and ST636, were found to be associated with multiple antibiotic resistance in DEC. Regarding antibiotic susceptibility, strains showed the highest resistance to amoxicillin, suggesting that this antibiotic may not be effective in treating DEC infections. On the other hand, the isolates demonstrated susceptibility to amikacin and chloramphenicol, implying that these antibiotics could be more suitable treatment options for DEC infections.

Conclusion

The findings underscore the importance of promptly identifying antibiotic resistance patterns and their correlation with specific pathogenic virulence categories, as this knowledge can aid in selecting the most appropriate antibiotics for treating DEC infections. Considering the antibiotic resistance profiles and associated resistance genes is crucial in managing and containing diarrheal outbreaks and in selecting effective antibiotic therapies for DEC infections.

The effects of ambient temperature and feeding regimens on cecum bacteria composition and circadian rhythm in growing rabbits

Seasonal environmental shifts and improper eating habits are the important causes of diarrhea in children and growing animals. Whether adjusting feeding time at varying temperatures can modify cecal bacterial structure and improve diarrhea remains unknown. Three batches growing rabbits with two groups per batch were raised under different feeding regimens (fed at daytime vs. nighttime) in spring, summer and winter separately, and contents were collected at six time points in 1 day and used 16S rRNA sequencing to investigate the effects of feeding regimens and season on the composition and circadian rhythms of cecum bacteria. Randomized forest regression screened 12 genera that were significantly associated with seasonal ambient temperature changes. Nighttime feeding reduced the abundance of the conditionally pathogenic bacteria Desulfovibrio and Alistipes in summer and Campylobacter in winter. And also increases the circadian rhythmic Amplicon Sequence Variants in the cecum, enhancing the rhythm of bacterial metabolic activity. This rhythmic metabolic profile of cecum bacteria may be conducive to the digestion and absorption of nutrients in the host cecum. In addition, this study has identified 9 genera that were affected by the combination of seasons and feeding time. In general, we found that seasons and feeding time and their combinations affect cecum composition and circadian rhythms, and that daytime feeding during summer and winter disrupts the balance of cecum bacteria of growing rabbits, which may adversely affect cecum health and induce diarrhea risk.

Comparative prevalence of diarrheagenic Escherichia coli between children below five years with close contact to food animals in Kisumu County, Kenya

Introduction

diarrheal infections in young children below five years and food animals are caused by diarrheagenic Escherichia coli strains. The study focused on understanding the association between DEC pathotypes in children below five years and food animals to establish the possibility of zoonotic transmission.

Methods

samples from 150 children who presented with diarrhea at the Kisumu County Hospital and 100 stool samples from food animals were collected and processed using culture methods. Molecular identification of the pathotypes was assayed using a primer-specific polymerase chain reaction that targeted the six virulence genes related to the diarrheagenic Escherichia coli pathotypes.

Results

one hundred and fifty-six study subjects (100 children samples and 56 food animals) samples were positive for E. coli polymerase chain reaction detection revealed a prevalence of (23%) among children below five years and a prevalence of (20%) among the food animals. Children samples showed Enteroaggregative Escherichia coli, having high phenotypic frequency of (12%) followed by Enterotoxigenic Escherichia coli, (5.3%) and Enteropathogenic Escherichia (3.3%) the least being mixed infections Enteroaggregative/Enterotoxigenic Escherichia coli and Enteroaggregative/Enteropathogenic Escherichia coli with (1.3%) respectively. The food animals found in children homesteads were detected to harbor pathogenic strains of E. coli. Enteropathogenic Escherichia coli was the most prevalent pathotypes detected in cattle (13%) followed by Enterotoxigenic Escherichia coli detected in goats at (4%) and poultry at (3%).

Conclusion

presence of diarrheagenic Escherichia coli in food animals could serve as reservoirs of transmitting these bacteria to children below five years.

Common Etiological Agents in Adult Patients with Gastroenteritis from Central Iran

Aims: This study represents the first analysis from Iran for both the frequency of the most common causes of infectious diarrhoea and their antibiotic resistance patterns in adult patients. Methods: Adult stool specimens (n = 211) were analyzed. Stool specimens were analyzed using standard microbiological, polymerase chain reaction, and reverse transcription polymerase chain reaction tests to identify bacterial, parasitic, and viral enteropathogens. Antibiotic resistance profiles were determined. Results: Enteropathogens were identified in 46.4% (98/211) of the surveyed samples. This included 33.1% (70/211) bacterial infections, including 9.9% (21/211) diarrheagenic Escherichia coli (DEC) and 8.5% (18/211) Shigella spp. We detected 7.1% (15/211) parasitic infections (mostly Giardia lamblia) and 6.1% (13/211) viral infections (mostly adenovirus). The DEC and Shigella spp. isolates included many multi-drug resistant (MDR) isolates (95.2% and 77.7%, respectively), and extended spectrum-β-lactamase (ESBL) genes were often present (57.1% and 61.1%, respectively). The most commonly identified ESBL genes in the DEC and Shigella spp. isolates were bla_TEM (100% in both species), bla_CTX-M15 (91.6% and 100%, respectively), AmpC bla_CIT (80% and 100%, respectively), and bla_DHA (80% and 100%, respectively). Conclusions: Bacterial infection was the primary cause of infectious diarrhea, affecting one-third of the adults. The frequency of DEC and Shigella spp. was higher than for other enteropathogens. The high prevalence of MDR, the elevated incidence of ESBL genes among Shigella spp. and DEC isolates, and the presence of quinolone resistance in the Salmonella spp. isolates represent a significant challenge for gastroenteritis diagnosis and treatment in this region.

Phylogrouping and characterization of Escherichia coli isolated from colonic biopsies and fecal samples of patients with flare of inflammatory bowel disease in Iran

BACKGROUND

Although the etiopathogenesis of inflammatory bowel disease (IBD) is still poorly understood, Escherichia coli has been described as a potential causative microorganism in IBD pathogenesis and also disease progression, offering a potential therapeutic target for disease management. Therefore, we conducted this study to investigate the pathotypes, phylogenetic groups, and antimicrobial resistance of E. coli isolates from patients with IBD in Iran.

METHODS

Fecal and biopsy colonic samples were collected from IBD patients experiencing flare-up episodes referred to Taleghani hospital in Tehran, Iran, between August 2020 and January 2021. Identification of E. coli strains was performed based on biochemical and molecular methods. Antibiotic susceptibility testing was performed as recommended by the Clinical and Laboratory Standards Institute. Phylogrouping and pathotyping of each isolate were carried out using polymerase chain reaction (PCR) and multilocus sequence typing (MLST) assays.

RESULTS

A total of 132 non-duplicate E. coli strains were isolated from 113 IBD patients, including 96 ulcerative colitis (UC), and 17 Crohn's disease (CD) patients. In our study, 55% of CD-related E. coli and 70.5% of UC-related isolates were non-susceptible to at least three or more unique antimicrobial classes, and were considered as multidrug-resistant (MDR) strains. E. coli strains exhibited a high level of resistance to cefazolin, ampicillin, tetracycline, ceftazidime, ciprofloxacin, and cefotaxime. Enterotoxigenic E. coli (ETEC) and diffusely adherent E. coli (DAEC) were the most prevalent pathotypes, and groups B2 and D were the predominant phylogroups.

CONCLUSION

In the present study, we found that E. coli strains that colonize the gut of Iranian patients with IBD most frequently belonged to phylogenetic groups B2 and D. We also conclude that E. coli isolates from IBD patients have been revealed to be resistant to commonly used antibiotics, in which most of them harbored strains that would be categorized as MDR.

Relationship Between Antibiotic Resistance, Biofilm Formation, and Biofilm-Specific Resistance in Escherichia coli Isolates from Ningbo, China

Purpose

Methods

Results

Conclusion