Extent of Antimicrobial Resistance (AMR) in an Ecosystem with Organized Livestock Farming in Sri Lanka

Abstract

Introduction: Intro Combating AMR is a major challenge in current era. This study aims to investigate the distribution of AMR and the Extended Spectrum Beta Lactamase (ESBL) among livestock, wild animals and environment in an ecosystem with a high density of organized livestock farms in Sri Lanka.

Methods: One square km area at Kosgama was mapped using GPS as the study area. In total 222 samples: feces from livestock and wild animals, soil and water from environment, were collected and Escherichia coli (E. coli) were isolated. Maximum of two E. coli per sample were tested to profile AMR for 12 antimicrobials. Among the E. coli, ESBL producers were screened and ESBL expressions were phenotypically detected using cefpodoxime combination disk kit. Prevalence of common ESBL genes: blaCTX-M, blaTEM, blaSHV was detected by PCR.

Findings: Seventy seven percent (61/79) of livestock, 62% (42/68) of wild animals, 79% (35/44) of soil and 68% (21/31) of water samples were positive for E. coli. Of the E. coli tested for AMR in livestock, the highest resistance (51.7%) was detected against tetracycline followed by ampicillin (39.4%) and nalidixic acid (37.7%). E. coli from wildlife (45%) and soil/ water (46.5%) reflected the highest resistance against streptomycin. Of the E. coli isolates, 31.5% (36/114) of livestock, 7.3% (6/82) of wildlife, 12.1% (8/66) of soil and 31.4% (11/35) of water were Multi Drug Resistant (MDR). Among 37 E. coli screened as ESBL, two from a mongoose (Herpestes edwardsii) were phenotypically positive for ESBL. Prevalence of ESBL genes were ∼49% (18/37) of which 17 carried blaTEM gene and one that expressed ESBL phenotypically contained blaCTX-M gene. Gene bla SHV was not detected.

Conclusion: Unexpected presence of AMR, MDR and ESBL E. coli particularly in wild animals and environment throw light on necessity of prudent use of antimicrobials.