Antimicrobial resistance and mcr-1 gene in Escherichia coli isolated from poultry samples submitted to a bacteriology laboratory in South Africa

• Published in: Veterinary World Vol. 14; no. 10; pp. 2662 - 2669
• Main Authors: Hassan, Ibrahim Z, Wandrag, Buks, Gouws, Johan J, Qekwana, Daniel N, Naidoo, Vinny
• Format: Journal Article
• Language: English
• Published: India Veterinary World 01.10.2021
• Subjects: antimicrobial resistance; colistin; escherichia coli; mobilized colistin resistance-1; poultry; poultry; mobilized colistin resistance-1; antimicrobial resistance; Escherichia coli; colistin
• ISSN: 0972-8988; 2231-0916
• DOI: 10.14202/vetworld.2021.2662-2669

Antimicrobial resistance (AMR) and recently mobilized colistin resistance ( ) associated colistin resistance among isolates have been attributed to the overuse of antimicrobials in livestock production. remains an important pathogen, often associated with mortality and low carcass weight in poultry medicine; therefore, the need to use antimicrobials is common. The study aimed to determine the AMR profile and presence of and genes in avian pathogenic from poultry samples tested at a bacteriology laboratory for routine diagnosis. This is a first step in understanding the effectiveness of mitigation strategies. Fifty strains were assessed for resistance against ten antimicrobial drugs using broth microdilution. All isolates with a colistin minimum inhibitory concentration (MIC) of 2 μg/mL were analyzed for the presence of and genes by employing the polymerase chain reaction. For each isolate, the following farm information was obtained: farm location, type of farm, and on-farm use of colistin. Sixty-eight percent of the strains were resistant to at least one antimicrobial; 44% were multiple drug-resistant (MDR). Most isolates were resistant to doxycycline (44%), trimethoprim-sulfamethoxazole (38%), ampicillin (32%), and enrofloxacin (32%). None of the strains was resistant to colistin sulfate (MIC of 2 μg/mL). Only one isolate held the gene; none carried the gene. Resistance among isolates in this study was fairly high. Resistance to commonly used antimicrobials was observed, such as doxycycline, trimethoprim-sulfamethoxazole, and enrofloxacin. Only a single strain carried the gene, suggesting that and genes are common among isolates in this study. The prevalence of AMR, however, suggests that farmers must implement standard biosecurity measures to reduce burden, and antimicrobial use to prolong the efficacy life span of some of these drugs.