Abundance of Multiple-Antibiotic-Resistant Salmonella Strains in Fecal Samples of Rhinoceros unicornis of the Kaziranga National Park, India

Abstract

Aims: This study was undertaken to assess the abundance of multiple-antibiotic-resistant (MAR) Salmonella strains in fecal samples of Rhinoceros unicornis of the Kaziranga National Park (KNP), India. Study Design: Antibiotic-resistance profile of the Salmonella isolates from fecal samples of rhinoceros was carried out by replica plating on Muller Hinton Agar (MHA) plates containing antibiotics. The presence of class 1 integrons in metallo-β-lactamase (MBL) producing Salmonella isolates was determined by multiplex PCR. Place and Duration of Study: The study was carried out on rhinos of KNP situated in the Golaghat district of Assam, India in April 2015. Methodology: Fresh rhino fecal samples (designated as 1R, 2R, 3R, 4R and 5R) were dilution plated onto MacConkey agar. Purified bacterial colonies were then streaked separately on bismuth sulphite (BS) agar plates. All black colonies which are characteric growth of Salmonella were selected and used to make master plates on Luria Agar. To determine the antibiotic-resistance profile of the isolates, master-plates of purified single colonies of Salmonella spp. were                  replicate-printed on plates containing antibiotics from the β-lactam, aminoglycoside, or quinolone groups. To detect the presence of an integron, a conserved segment polymerase chain reaction was used. Results: 97.6% of the Salmonella isolates tested were resistant to >1 antibiotics (multidrug resistant or MAR). A total of 100 isolates from two fecal samples, 4R and 5R, were found to be imipenem resistant; 52 of them tested positive for the presence of MBLs. Five of the twenty MBL producing strains contained class 1 integrons. Conclusion: Because Salmonella is usually spread by drinking contaminated water, it is likely that water bodies in KNP are contaminated with MAR Salmonella strains. In case of Salmonellosis outbreak among Indian one-horned rhinos, our antibiogram will assist the veterinarians to choose the appropriate regimen of antibiotics for the rhinos in the KNP.