Antimicrobial resistance against fluoroquinolones and cephalosporins of Escherichia coli and Klebsiella pnuemoniae in chickens entering the food chain in Mwanza, Tanzania

Abstract

The use of antimicrobials in poultry production accelerated the emergency and spread of antimicrobial resistance. AMR data of commensal resistant bacteria in chicken to antibiotics considered essential in animals and humans is lacking in poor countries. This study was conducted to determine the resistance patterns of E. coli, K. pnuemoniae, and ESBL producing bacteria to fluoroquinolones and cephalosporins in healthy chickens, and to assess the risk that can be posed by resistant bacteria to humans. A cross-sectional and time series study was conducted to obtain faeces from healthy chickens from biosecurity level 1 and 2 poultry farms between May and September 2021. Bacterial isolates were identified by biochemical test. Disc diffusion method was used to test susceptibility of E. coli and K. pneumoniae isolates to ciprofloxacin, ceftriaxone and cefepime according to CLSI standard. A total of 200 pooled fresh faecal samples were collected; 189 samples were from biosecurity level 1 and 11 were from level 2. Similarly, 104 samples were collected from layers and 96 from broiler chickens. In total, 150 strains were isolated: 80 were from broiler samples; and 70 strains were from layer chicken samples. Overall, the prevalence of E. coli was 75%; and no K. pneumoniae was isolated. The resistance of E. coli was 63.3% against ciprofloxacin, 0.7% against ceftriaxone, and 0% against cefepime. No ESBL-producing E. coli was detected. This study revealed that resistance to fluoroquinolones is high and that of cephalosporins is emerging in poultry production. The risk associated with high prevalence of commensal E. coli is significant due to transmission of AMR to human via food and environmental contamination.