ORIGINAL ARTICLE   

Minerva Biotecnologica 2020 June;32(2):58-63

DOI: 10.23736/S1120-4826.20.02611-7

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Molecular detection of main resistance genes by nested PCR in Salmonella spp. isolated from raw meat and stool samples in Niger State, Nigeria

Dickson A. MUSA ¹, Kolawole H. AREMU ², Zainab A. ADEBAYO ³, Rinaldo PELLICANO ⁴, Stella I. SMITH ⁵ ✉

¹ Department of Biochemistry, Ibrahim Badamasi Babangida University, Lapai, Nigeria; ² Department of Biochemistry, Osun State University, Osogbo, Nigeria; ³ Department of Microbiology, University of Ibadan, Ibadan, Nigeria; ⁴ Unit of Gastroenterology, Molinette Hospital, Turin, Italy; ⁵ Department of Molecular Biology and Biotechnology, Nigerian Institute of Medical Research, Lagos, Nigeria

BACKGROUND: Infections caused by Salmonella spp. remain an important public health threat especially in developing countries. In recent years, rapid emergence of antibiotics resistance has resulted in the inefficacy of available treatment options which has led to exponential increase in mortality and economic burden. The study aimed to screen Salmonella spp. for resistance genes to frequently used antibiotics and establishing the distribution of these genes across Niger State.
METHODS: Ninety-eight samples comprising 72 raw meat and 26 stool samples were analyzed for the presence of Salmonella spp. Antimicrobial susceptibility of Salmonella isolates was determined by the Kirby-Bauer disc diffusion method and amplification of resistance genes namely blaTEM, catP and gyrA were carried out using nested polymerase chain reaction (PCR) technique.
RESULTS: Thirty-one (31.6%) isolates were positive for Salmonella spp. The distributions of the isolates were 22 of 31 (70.97%) in raw meat and nine of 31 (29.03%) in stool. Salmonella isolates were susceptible to ciprofloxacin (93.5%) but highly resistant to ampicillin (100%), chloramphenicol (96.8%), nalidixic acid (93.5%), tetracycline and ceftriaxone (90.3%), erythromycin (77.4%), cotrimoxazole (64.5%). High levels of blaTEM and catP genes and relatively low gyrA gene distributions were observed in isolates from stool and raw meat samples across the state.
CONCLUSIONS: These data suggest that there is a high prevalence of ampicillin and chloramphenicol resistance by Salmonella spp. as shown by high levels of blaTEM, gyrA and catP genes while gyrA distribution is rare across Niger State.

KEY WORDS: Salmonella; Drug resistance; Polymerase chain reaction; Nigeria