Determination of antibiotic resistance patterns and genotypes of Escherichia coli isolated from wild birds

Abstract

Background Curbing the potential negative impact of antibiotic resistance, one of our era's growing global public health crises, requires regular monitoring of the resistance situations, including the reservoir of resistance genes. Wild birds, a possible bioindicator of antibiotic resistance, have been suggested to play a role in the dissemination of antibiotic-resistant bacteria. Therefore, this study was conducted with the objective of determining the phenotypic and genotypic antibiotic resistance profiles of 100 Escherichia coli isolates of gull and pigeon origin by using the Kirby-Bauer disk diffusion method and PCR. Furthermore, the genetic relationships of the isolates were determined by RAPD-PCR. Results Phenotypic antibiotic susceptibility testing revealed that 63% (63/100) and 29% (29/100) of E. coli isolates were resistant to at least one antibiotic and multidrug-resistant (MDR), respectively. With the exception of cephalothin, to which the E. coli isolates were 100% susceptible, tetracycline (52%), kanamycin (38%), streptomycin (37%), ampicillin (28%), chloramphenicol (21%), trimethoprim/sulfamethoxazole (19%), gentamicin (13%), enrofloxacin (12%) and ciprofloxacin (12%) resistances were detected at varying degrees. Among the investigated resistance genes, tet(B) (66%), tet(A) (63%), aphA1 (48%), sul3 (34%), sul2 (26%), strA/strB (24%) and sul1 (16%) were detected. Regarding the genetic diversity of the isolates, the RAPD-PCR-based dendrograms divided both pigeon and gull isolates into five different clusters based on a 70% similarity threshold. Dendrogram analysis revealed 47–100% similarities among pigeon-origin strains and 40–100% similarities among gull-origin E.coli strains. Conclusions This study revealed that gulls and pigeons carry MDR E. coli isolates, which may pose a risk to animal and human health by contaminating the environment with their feces. However, a large-scale epidemiological study investigating the genetic relationship of the strains from a "one health" point of view is warranted to determine the possible transmission patterns of antibiotic-resistant bacteria between wild birds, the environment, humans, and other hosts.

ESBL-Producing Enterobacterales at the Human–Domestic Animal–Wildlife Interface: A One Health Approach to Antimicrobial Resistance in Piauí, Northeastern Brazil

“…Our results corroborate the findings of [14], revealing that wild birds can carry strains of E. coli that are resistant to drugs of critical importance in human and veterinary medicine, suggesting that wild birds may serve as a reservoir for multidrug-resistant bacteria and resistance genes. However, these authors analyzed samples from pigeons and gulls, animals that have greater contact with humans and higher adaptation to anthropic areas, which may lead to increased contamination and a higher occurrence of antimicrobial resistant bacteria than in the samples from our study.…”

“…Antimicrobial resistance can be considered a classic example of a One Health challenge [13,14]. In other words, ARGs are examples of the interconnection between people, other animals, plants, and the environment shared by all, since the misuse of many antimicrobials may create favorable conditions for bacteria to fix resistance genes that can be transmitted to humans and animals through contaminated food or the environment.…”

High prevalence of multi-drug resistant bacteria in faecal samples from UK passerine birds

“…In the Azores archipelago, AMR within E. coli isolates was shown to be 24.3% (Santos et al, 2013), but increases to values of 63% in Turkey (Ahmed and Gulhan, 2024). Resistance levels vary, although similarly to our study, resistance to ampicillin tends to be common (Guenther et al, 2010;Merkeviciene et al, 2018;Ong et al, 2020;Santos et al, 2013;Skarżyńska et al, 2021), although other studies such as that conducted in Poland by Nowaczek et al (2021) report a lower prevalence at 28.1% and 16.7% reported by Yuan et al (2021).…”