Quantification of antibiotic resistance genes in wildlife ungulates in Ngorongoro Conservation area and Mikumi National Park, Tanzania

Abstract

Wild-animals can act as reservoirs for resistant bacteria and transfer of resistance genes in the environment. These genes can spread to livestock and human either directly by transmission of shared resistant bacteria, or by horizontal gene-transfer to environmental bacteria. To ascertain at what extent wild-animals carry resistance genes, eight faecal samples from buffalo, zebra and wildebeest from Ngorongoro Conservation Area (NCA) and Mikumi National Park (MNP), and four control samples from local zebu cattle grazing together with wildlife in NCA. The qPCR was carried on 14 antimicrobial resistance genes including tetracycline (tet(A), tet(B), 93 tet(C), tet(M), tet(O), tet(W), macrolide, lincosamide, streptogramin B (ermB, ermF), sulphonamide (sulI, sulII), beta-lactam (blaCTX-M-1 group, blaCMY-2, blaSHV) and glycopeptide (vanA). Samples from NCA, both wildlife and cattle were positive for 8 out of 14 resistance genes. The most prevalent genes were tet(W) and blaCMY-2 with the latter being of concern in encoding ESBL-type resistance. Three samples from Buffalo not interacting with cattle in MNP, were positive for tet(W) and blaCMY-2, and in addition for sulI. This suggests that wild ungulates on savannah, irrespective of contact with cattle, may constitute a reservoir for antimicrobial resistance determinants. Further studies are indicated to determine resistance gene-pool among wildlife animals