Author(s)

Dan Waithiru^1,2*, John Mwaniki Njeru², John M. Maingi¹, Erastus Mulinge², Benjamin Ngugi², John Maina², John Kiiru²

¹Department of Biochemistry, Biotechnology & Microbiology, Kenyatta University, Nairobi, Kenya.
²Centre for Microbiology Research, Kenya Medical Research Institute, Nairobi, Kenya.

The use of antibiotics for prophylaxis and growth enhancement in livestock farming is on the increase globally. This practice has led to the emergence and spread of antimicrobial-resistant bacteria in livestock. Only limited research has been done to establish the role of cattle farming in antimicrobial resistance. The current study sought to establish the carriage of multi-drug resistance and extended-spectrum beta-lactamase genes in Escherichia coli from farmers, their cattle, and cattle slurry within Kiambu County. A total of 286 (81%) E. coli isolates were recovered from 352 samples analysed. Antibiotic resistance profiles showed 114 (40%) isolates were resistant to ≥3 antimicrobial classes and were considered multidrug-resistant. Among multidrug-resistant (MDR) E. coli strains, 40 (14%) were resistant to 3 different antimicrobial classes, while 71 (25%) were resistant to between 4 and 7 antibiotic classes. Extended-spectrum β-lactamase resistance was found in 18 isolates: human (n = 14), cattle (n = 2), and environmental (n = 2). Both the bla_CTX-M and bla_TEM genes were detected in 10 and 15 strains, respectively. Sequence analysis showed that the isolates carried the bla_TEM-116 (n = 7), bla_TEM-1 (n = 5), and bla_CTX-M-15 (n = 8) genes. Genotyping MDR isolates using (GTG) ₅ PCR demonstrated that the isolates were not clonal. This data shows antimicrobial resistance profiles and different types of resistance genes in the E. coli population on dairy farms. As a result, more effective, targeted public health policies and measures need to be put in place to control and prevent the emergence and spread of resistant bacteria.

Humans, Cattle Slurry, Escherichia coli, Multidrug Resistance, Extended-Spectrum β-Lactamase (ESBL), TEM 116, CTX-M-15, Kenya

Waithiru, D. , Njeru, J. , Maingi, J. , Mulinge, E. , Ngugi, B. , Maina, J. and Kiiru, J. (2022) Unravelling Antimicrobial Resistance Phenotypes and Carriage of Extended-Spectrum β-Lactamase Genes in Escherichia coli Isolated from Dairy Farms in Kiambu County, Kenya. Advances in Microbiology, 12, 295-315. doi: 10.4236/aim.2022.125021.