Extended-spectrum β-lactamase prevalence and virulence factor characterization of enterotoxigenic Escherichia coli responsible for acute diarrhea in Nepal from 2001 to 2016

Abstract

BackgroundMultidrug-resistant (MDR) Gram-negative bacterial species are an increasingly dangerous public health threat, and are now endemic in many areas of South Asia. However, there are a lack of comprehensive data from many countries in this region determining historic and current MDR prevalence. Enterotoxigenic Escherichia coli (ETEC) is a leading cause of both acute infant diarrhea and traveler’s diarrhea in Nepal. The MDR prevalence and associated resistance mechanisms of ETEC isolates responsible for enteric infections in Nepal are largely unknown.MethodsA total of 265 ETEC isolates were obtained from acute diarrheal samples (263/265) or patient control samples (2/265) at traveler’s clinics or regional hospitals in Nepal from 2001 to 2016. Isolates were screened for antibiotic resistance, to include extended spectrum beta-lactamase (ESBL) production, via the Microscan Automated Microbiology System. ETEC virulence factors, specifically enterotoxins and colonization factors (CFs), were detected using multiplex PCR, and prevalence in the total isolate population was compared to ESBL-positive isolates. ESBL-positive isolates were assessed using multiplex PCR for genetic markers potentially responsible for observed resistance.ResultsA total of 118/265 (44.5%) ETEC isolates demonstrated resistance to ≥2 antibiotics. ESBL-positive phenotypes were detected in 40/265 isolates, with isolates from 2008, 2013, 2014, and 2016 demonstrating ESBL prevalence rates of 1.5, 34.5, 31.2, and 35.0% respectively. No difference was observed in overall enterotoxin characterization between the total ETEC and ESBL-positive populations. The CFs CS2 (13.6%), CS3 (25.3%), CS6 (30.2%), and CS21 (62.6%) were the most prevalent in the total ETEC population. The ESBL-positive ETEC isolates exhibited a higher association trend with the CFs CS2 (37.5%), CS3 (35%), CS6 (42.5%), and CS21 (67.5%). The primary ESBL gene identified was blaCTX-M-15 (80%), followed by blaSHV-12 (20%) and blaCTX-M-14 (2.5%). The beta-lactamase genes blaTEM-1 (40%) and blaCMY-2 (2.5%) were also identified. It was determined that 42.5% of the ESBL-positive isolates carried multiple resistance genes.ConclusionOver 30% of ETEC isolates collected post-2013 and evaluated in this study demonstrated ESBL resistance. Persistent surveillance and characterization of enteric ETEC isolates are vital for tracking the community presence of MDR bacterial species in order to recommend effective treatment strategies and help mitigate the spread of resistant pathogens.

Molecular Prevalence and Epidemiological Characteristics of Diarrheagenic <i>E. coli</i> in Children under 5 Years Old in the City of Koula-Moutou, East-Central Gabon

“…The characterization of virulence factors not only makes it possible to classify the different pathotypes of the E. coli strains, but also these factors are of particular interest as potential targets in therapeutic and/or vaccine trials [57]. For the ETEC pathotype, the prevalence of the enterotoxin ST gene was highest and there were no isolates combining both enterotoxin types in this study.…”

Untitled

“…The correlation between zone sizes and MIC values was then assessed using regression analysis and regression lines were used for extrapolating zone interpretive limits that corresponded to the MIC breakpoint values that defined susceptible, intermediate and resistant categorical results [17][18][19][20][21][22][23][24][25][26][27][28] .…”

Multidrug-Resistant Lineage of Enterotoxigenic Escherichia coli ST182 With Serotype O169:H41 in Airline Waste

“…Traveller’s diarrhoea is the most common health problem afflicting visitors to lower socioeconomic regions, affecting up to 40% of travellers ( Leung et al, 2019 ). While most cases are mild and self-limiting, typically resolving within two days ( Tribble, 2017 ), severe cases can present with cholera-like watery stools, result in the loss of 10 L of fluids daily, and can lead to hospitalisation and even death ( Margulieux et al, 2018 ; Mirhoseini et al, 2018 ; Hosangadi et al, 2019 ). Antimicrobial treatment for traveller’s diarrhoea reduces both symptoms and duration of the illness ( Diemert, 2006 ).…”