Occurrence of Listeria species in different captive wild animals of Nandankanan Zoo, Baranga, Odisha, India

Abstract

Listeria species were isolated from faecal samples collected from different captive wild animals of Nandankanan Zoo, Baranga, Odisha, using selective enrichment medium. The isolates were characterized based on their cell morphology, biochemical and sugar fermentation characteristics as well as culture morphology. Further, in vitro and in vivo pathogenicity tests were carried out to assess the pathogenic potential of the isolates. Listeria were found in 24 (23.07%) of the total 104 faecal samples. Listeria were isolated from the samples of tiger, bear, hyena, leopard, zebra, elephant, jackal, lion, barking deer, porcupine, chital, monkey and wild boar. Out of the 24 Listeria isolates 11 were confirmed as L. monocytogenes. The other 13 isolates included L. innocua, L. seeligeri, L. welshimeri and L. ivanovii. The pathogenicity study revealed that only four isolates were pathogenic. Three of these were L. monocytogenes isolated from tiger, hyena and elephant and one was L. ivanovii isolated from leopard. Antibiotic sensitivity of the 24 isolates was high towards ciprofloxacin, levofloxacin, amoxicillin, azithromycin and enrofloxacin. The isolates showed resistance towards oxytetracyclin, gentamicin, cephadroxil, penicillin-G and nalidixic acid.