Abstract
Wild birds can be colonized by bacteria, which are often resistant to antibiotics and have various virulence profiles. The aim of this study was to analyze antibiotic resistance mechanisms and virulence profiles in relation to the phylogenetic group of E. coli strains that were isolated from the GI tract of wildfowl. Out of 241 faecal samples, presence of E. coli resistant to a cephalosporin (ESBL/AmpC) was estimated for 33 isolates (13,7%). Based on the analysis of the coexistence of 4 genes encoding ESBLs/AmpC (blaCTX-M, blaTEM, blaSHV, blaAmpC) and class 1 and 2 integrons genes (intI1, intI2) a subset of two resistance profiles was observed among the investigated E. coli isolates carrying blaAmpC, blaSHV, and blaCTX-M, blaTEM, class 1 and 2 integrons, respectively. The E. coli isolates were categorized into 4 phylogenetic groups A (39.4%), B2 (24.25%), D (24.25%) and B1 (12.1%). The pathogenic B2 and D groups were mainly typical for the Laridae family. Among the 28 virulence factors (Vfs) detected in pathogenic phylogenetic groups B2 and D, 7 were exclusively found in those groups (sfa, vat, tosA, tosB, hly, usp, cnf), while 4 VFs (fecA, fyuA, irp2, kspMTII) showed a statistically significant association (P≤0.05) with phylogroups A and B1. Our results indicated that strains belonging to commensal phylogroups A/B1 possess extensive iron acquisition systems (93,9%) and autotransporters (60,6%), typical for pathogens, hence we suggest that these strains evolve towards higher levels of virulence. This study, which is a point assessment of the virulence and drug resistance potential of wild birds, confirms the importance of taking wild birds as a reservoir of strains that pose a growing threat to humans. The E. coli analyzed in our study derive from different phylogenetic groups and possess an arsenal of antibiotic resistance genes and virulence factors that contribute to their ability to cause diseases.
Highlights
Dissemination of multidrug-resistant (MDR) bacteria is a significant worldwide problem [1]
The extraintestinal pathogenic (ExPEC) pathotype can be further subdivided into uropathogenic E. coli (UPEC), neonatal E. coli meningitis (NMEC), E. coli associated with sepsis (SEPEC) and avian pathogenic E. coli (APEC)
We found that two E. coli isolates recovered from two Mallards captured in different locations exhibited an identical polymerase chain reaction (PCR) MP profile
Summary
Dissemination of multidrug-resistant (MDR) bacteria is a significant worldwide problem [1]. The production of extended-spectrum β-lactamases (ESBLs), AmpC-type β-lactamases and carbapenemases is one of the most clinically and epidemiologically important mechanisms of resistance to antibiotics in Enterobacterales [2]. E. coli is most commonly used as a representative indicator of antimicrobial resistance in Gram-negative bacteria and may be relevant to human as well as veterinary medicine [2]. A worldwide increase in ESBL-producing E. coli isolates in both community and hospital settings has been observed since early 2000 [3]. The transmission of E. coli between hosts begins from gut colonisation. On the basis of virulence factors E. coli can be classified into intestinal pathogenic (IPEC) and extraintestinal pathogenic (ExPEC) strains. Whereas IPEC strains are obligate pathogens, ExPEC are facultative pathogens which belong to the normal gut flora and do not provoke the symptom of disease. ExPECs probably do not exhibit host specificity or it is wide, including humans and birds [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
