Prevalence and Genetic Relationship of Predominant Escherichia coli Serotypes Isolated from Poultry, Wild Animals, and Environment in the Mekong Delta, Vietnam

Abstract

Avian pathogenic Escherichia coli (APEC) is the main causative agent of avian colibacillosis, which is an important systemic disease of profound economic and clinical consequences for the poultry industry worldwide. In this study, 975 E. coli strains were isolated from 2,169 samples collected from cloacal swabs of chickens, in-farm wild animals (ants, geckos, flies, and rats), and environment. The highest proportion of E. coli isolation was obtained from chicken cloacal swabs with 71.05% (95% confidence interval (CI) 66.69–75.05%) followed by the proportions of 38.15% (95% CI 35.41–40.97%) and 38.11% (95% CI 34.15–42.24%) from wild animals or environment, respectively. Distribution of O-antigen serotypes of the E. coli isolates, including O1, O2, O18, and O78, was determined by PCR. The most predominant serotype was O18 (10.56%) followed by O2 (9.44%), O1 (7.79%), and O78 (6.56%). Of note, serotype O18 was more likely distributed in the examined wild animals, especially in geckos. Polymorphic DNA fingerprints, generated by ERIC-PCR, of representative E. coli strains of each serotype revealed genetic heterogeneity of the examined E. coli, and O18 was more divergent with 63 clusters formed from 66 isolates. Furthermore, several E. coli strains from different sample sources shared high DNA fingerprint relatedness, suggesting that there exists complex transmission of E. coli from chickens to wild animals and environment and vice versa in poultry husbandry settings. Although pathotypes of the examined E. coli were not determined in this study, our results provided important findings of epidemiological and genetic characteristics of E. coli in the Mekong Delta and highlighted the prerequisite of stricter biocontainment to reduce the prevalence and consequences of APEC in poultry production.

Surveillance of Escherichia coli in different types of chicken and duck hatcheries: one health outlook

“… Aworh et al (2021) showed that 26.8% of tested samples were positive for E. coli , 42.7% isolated from poultry workers, 32.7% from chickens, and 24.5% from poultry farms’ environments. Consistent with the findings of Nguyen et al (2021) , who found an incidence of 38.11% of E. coli in ecological samples from automatic hatcheries, we found prevalence rates of 31.3, 40, and 100% in the environments of semiautomatic and manual hatcheries, respectively.…”

“…Serotyping of the E. coli isolates obtained in this inquiry was deemed crucial in order to ascertain the epidemiological status and align with the one health agenda of the relevant organizations. The O:H serotyping was used as the current gold standard grouping for E. coli taxonomy and epidemiology ( Scheutz et al, 2004 ; Nguyen et al, 2021 ).…”

“…From one health point of view, distinct specific E. coli “O” serotypes of APEC were verified to be closely correlated with several serious infections in animals and humans; moreover, APEC belonging to “O1, O2, O18, and O78” serotypes are considered as the most pathogenic strains ( Mehat et al, 2021 ; Nguyen et al, 2021 ).…”

Bacterial and viral rodent-borne infections on poultry farms. An attempt at a systematic review

“…Among the different vectors of APEC such as houseflies, beetles and wild birds are also rodents, and they need to be kept out of poultry houses ( 12 ). Studies of APEC in chickens, wild animals with habitats on farms (including rats), and in the environment in Vietnam revealed complex transmission of E. coli from chickens to wild animals including rodents and to the environment and vice versa ( 47 , 48 ). Although the most important reservoir of verotoxigenic E. coli (VTEC) strains are ruminants, especially cattle, another important reservoir are also rodents, especially rats.…”

Virulence Factors and Antimicrobial Resistance Profile of Escherichia Coli Isolated from Laying Hens in Italy

“…A study carried out in France identified 12 different serogroups, with the most frequently isolated ones being serogroups O2, O8, O25 and O78 [ 13 ]; likewise, a Greek survey mainly identified O78, O2 and O11 [ 14 ]. Studies from different Asian countries highlight a high prevalence of serogroups O78 and O2 [ 15 , 16 ], but also O1 and O18 displayed a relevant prevalence [ 17 ].…”