Antimicrobial Resistance Profile and Characterization of ESBLs in Escherichia coli from Camels in Northern Kenya

Abstract

Purpose: One-humped camels (Camelus dromedarius), have increased significantly as camel products are widely used thus contributing to food security of Kenya's arid and semi-arid lands (ASALs). Camel husbandry management practices are hypothesized to be encouraging exposure to antimicrobials, development and spread of antimicrobial resistance genes including extended-spectrum beta-lactamases (ESBLs-). However, there is limited data on levels of antimicrobial resistance (AMR) in camels reared under different animal production systems. We present data on antimicrobial susceptibility profile and characterization of ESBL- encoding genes in Escherichia coli recovered from camels reared under intensive and extensive production systems in Northern Kenya. Methods & Materials: We carried out a cross-sectional study on 304 camels reared by pastoral communities (extensive production system) (n=137) and ranchers (intensive production system) (n=167). E. coli isolates were screened from all fecal samples and subjected to antimicrobial susceptibility test (AST) against 15 antimicrobials. Beta-lactamase genes were identified through PCR, gel electrophoresis and gel imaging and sequencing. Results: A total of 123 (40.46%) E. coli were isolated from all fecal samples collected from camels. Antimicrobial resistance was observed in 59 (47.97%) of E. coli after conducting AST. The highest resistance was observed in beta-lactam antibiotics than other classes of antibiotics: cefaclor 35 (28.46%), cefotaxime 20 (16.26%), ampicillin 12 (9.76%), ceftazidime 10 (8.13%) and tetracycline 6 (4.87%). Out of 123 isolates, 4 (3.25%) ESBL-producing E. coli containing bla CTX-M-15 and bla TEM-214 (n=1); bla CTX-M-15 and bla TEM 243 (n=2) and, blaCTX-M-27 (1) displaying multi-drug resistance phenotype were observed. Other variants of beta-lactamase genes namely blaTEM-1 (1) blaTEM-243 (2), blaTEM-116 (14), and blaTEM-104 (1) with broad-spectrum beta-lactamase activity were detected in 18 isolates. There was no significant association between type of camel rearing systems and occurrence of antimicrobial resistance (p value=0.61). Generally, intensive camel farming showed an upward trend in antibiotic resistance as compared to extensive camel farming. Conclusion: Our findings shed light on increase in AMR, different variants of ESBL and non-ESBL-encoding genes found in E. coli recovered from camels regardless of the type of farming practice. These results recommend prudent veterinary usage of beta-lactams in the camel industry.