Comparison of Antibiotic Resistance and Virulence Factors amongEscherichia coliIsolated from Conventional and Free-Range Poultry

Abstract

Microbiological contamination in commercial poultry production has caused concerns for human health because of both the presence of pathogenic microorganisms and the increase in antimicrobial resistance in bacterial strains that can cause treatment failure of human infections. The aim of our study was to analyze the profile of antimicrobial resistance and virulence factors of E. coli isolates from chicken carcasses obtained from different farming systems (conventional and free-range poultry). A total of 156 E. coli strains were isolated and characterized for genes encoding virulence factors described in extraintestinal pathogenic E. coli (ExPEC). Antimicrobial susceptibility testing was performed for 15 antimicrobials, and strains were confirmed as extended spectrum of β-lactamases- (ESBLs-) producing E. coli by phenotypic and genotypic tests. The results indicated that strains from free-range poultry have fewer virulence factors than strains from conventional poultry. Strains from conventionally raised chickens had a higher frequency of antimicrobial resistance for all antibiotics tested and also exhibited genes encoding ESBL and AmpC, unlike free-range poultry isolates, which did not. Group 2 CTX-M and CIT were the most prevalent ESBL and AmpC genes, respectively. The farming systems of poultries can be related with the frequency of virulence factors and resistance to antimicrobials in bacteria.

Comparison of antibiotic resistance pattern among Enteropathogenic bacteria isolated from broiler and backyard chicken meat

“…This study is supported by several previous studies, where the resistance rates of organic chicken meat isolates to the antimicrobial agents found in commonly used as poultry drugs, such as quinolones (ciprofloxacin), tetracycline (doxycycline), chloramphenicol, gentamicin, penicillin, streptomycin, spectinomycin and sulfonamide (sulfisoxazole), were significantly lower than those obtained from conventional chicken and turkey meat that had been treated with antibiotics (Miranda et al, 2008). Cormican et al (2001) dan Koga et al (2015), showed that higher frequency of Enterobacteriaceae resistance strains isolated from conventionally raised poultry than freerange or organic poultry; as a result, the use of antimicrobial agents is more common in conventionally poultry farm than free-range or organic poultry.…”

Variations of antibiotic resistance profiles in chickens during administration of amoxicillin, chlortetracycline and florfenicol

“…Studies of antibiotic resistance in E. coli isolated from chickens indicate that ARGs have spread widely (Kilonzonthenge et al 2013;Zhang et al 2013;Chen et al 2014;Wu et al 2014;Koga et al 2015;Wolny-Koladka and Lenart-Boron 2016). In our experiments, we found that the antibiotic susceptibility in E. coli isolated from chickens was high.…”

“…; Koga et al . ; Wolny‐Koladka and Lenart‐Boron ). In our experiments, we found that the antibiotic susceptibility in E. coli isolated from chickens was high.…”

“…β ‐lactams are the antibiotics used most frequently for infections caused by Enterobacteriaceae (Koga et al . ) and this has contributed to the emergence of a large number of β ‐lactam resistance genes such as variants of bla TEM , bla CTX‐M , bla SHV , bla CMY and bla NDM (Rice ; Blair et al . ).…”

“…In our study, resistance to chlortetracycline was correlated with increased gene copy numbers of ARGs involved in tetracycline resistance. b-lactams are the antibiotics used most frequently for infections caused by Enterobacteriaceae (Koga et al 2015) and this has contributed to the emergence of a large number of b-lactam resistance genes such as variants of bla TEM , bla CTX-M , bla SHV , bla CMY and bla NDM (Rice 2012;Blair et al 2015). In the current study, bla TEM was the dominant ARG at the 15-day time point.…”