Antimicrobial resistance in indicator bacterial species from wildlife at the human- livestock-wildlife interface in the Mnisi community, Mpumalanga, South Africa

Abstract

Antimicrobial resistance (AMR) is one of the greatest threats currently facing humanity. While there have been extensive studies on this subject in public health and livestock, there is paucity of information on the epidemiological role of wildlife in AMR. Anthropogenic activities have been suggested to be the main reason for presence of AMR in wildlife. Wildlife can also be a reservoir of naturally occurring resistance. While a one health approach has been put in place to tackle AMR, there have been obstacles in implementing it. The aim of this study was to determine the resistance of E. coli and Enterococcus isolates from wildlife faecal samples. Fifty-one wildlife faecal samples (herbivores and carnivores) collected from Mnisi between 2015 and 2020 and stored in a biobank at Hans Hoheisen Research Station were used in this study. Isolation of E. coli and Enterococcus was done on MacConkey and Blood agar and Biochemical tests done to identify isolates. Minimum inhibitory concentration was done using Thermo Scientific Sensititre plates according to manufacturer recommendations and interpreted using Clinical Laboratory Standards Institute standard tables. A total of 14 E. coli and 42 Enterococcus isolates were obtained. 52% of the Enterococcus isolates were identified as E. faecium and 48% as E. faecalis. Antimicrobial susceptibility analysis for E. coli showed one multidrug resistant isolate, 14% susceptibility to cefuroxime and 7% susceptibility to cefazolin, cefepime, ceftriaxone, cefoxitin and cefpodoxime and imipenem. Antimicrobial susceptibility for Enterococcus revealed 42% of isolates had multi drug resistance. Daptomycin, Rifampin and Quinuptistin/dalfopristin had highest resistance of 71%, 64% and 43% respectively. The proximity of the wildlife to livestock and human settlement is likely to be related to the high level of resistance as sewage wastes, run off water and environmental contamination may be responsible for the dissemination of resistant genes. The results of this study show that wildlife is a major player in antimicrobial resistance. The researchers recommend follow up studies and AMR surveillance in wildlife, human hospitals, livestock and water bodies in the area.