Occurrence, antimicrobial resistance and whole genome sequence analysis of Salmonella serovars from pig farms in Ilorin, North-central Nigeria

Salmonella enterica is a foodborne pathogen of global public health importance with developing countries mostly affected. Foodborne outbreaks are often attributed to pork consumption and Salmonella contamination of retail pork is directly linked to the Salmonella prevalence on farm. The widespread u...

Full description

Saved in:

Bibliographic Details
Published in:	International journal of food microbiology Vol. 350; p. 109245
Main Authors:	Raufu, I.A., Ahmed, O.A., Aremu, A., Ameh, J.A., Timme, R.E., Hendriksen, R.S., Ambali, A.G.
Format:	Journal Article
Language:	English
Published:	Amsterdam Elsevier B.V 16-07-2021 Elsevier BV
Subjects:	Acid resistance Antimicrobial agents Antimicrobial resistance Ciprofloxacin Contamination Developing countries Drug resistance Farms Foodborne diseases Foodborne pathogens Gene sequencing Genomes Isolation media LDCs MLST Multilocus sequence typing Mutation Nalidixic acid Nucleotide sequence Nucleotides Pathogens Phylogeny Plasmids Polymorphism Pork Public health Resistance Salmonella Salmonella serotypes Selective media Serotyping Single-nucleotide polymorphism Swine Swine production Virulence Virulence genes Whole genome sequencing Nigeria Ilorin Nigeria Resistance Salmonella serotypes MLST Virulence genes Plasmids
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Salmonella enterica is a foodborne pathogen of global public health importance with developing countries mostly affected. Foodborne outbreaks are often attributed to pork consumption and Salmonella contamination of retail pork is directly linked to the Salmonella prevalence on farm. The widespread use of antimicrobials at different steps of swine production can favor resistant strains of Salmonella. The objectives of this study are to characterize the distribution, multilocus sequence typing (MLST), plasmid, virulence profiles and antimicrobial resistance of Salmonella serovars circulating in selected pig farms. Six hundred fecal samples were randomly collected from nine selected farms in Ilorin, Nigeria. Isolates were analyzed by cultural isolation using selective media, conventional biochemical characterization, serotyping, MLST and whole genome sequencing (WGS). Sixteen samples were positive for Salmonella sub-species, comprising of nine serovars. The antimicrobial susceptibility results revealed low-level resistance against 13 antimicrobial agents. Five strains exhibited resistance to nalidixic acid and intermediate resistance to ciprofloxacin with chromosomal (double) mutation at gyrA and parC while four strains possessed single mutation in parC. Salmonella Kentucky showed double mutation each at gyrA and parC. WGS analysis, revealed eight diverse sequence types (STs), the most common STs were ST-321 and ST-19 (n = 4) exhibited by S. Muenster and S. Typhimurium, respectively. Single Nucleotide Polymorphism (SNP)-based phylogeny analysis showed the 16 isolates to be highly related and fell into 8 existing clusters at NCBI Pathogen Detection. Curtailing the spread of resistant strains will require the establishment of continuous surveillance program at the state and national levels in Nigeria. This study provides useful information for further studies on antimicrobial resistance mechanisms in foodborne Salmonella species. •Sixteen Salmonella enterica isolates comprising nine serovars were obtained.•Most of the isolates showed low-level phenotypic resistance to common antimicrobials.•Multilocus sequence typing identified seven different sequence types (STs).•Detection of several virulence genes supports the pathogenic potential of isolates.•Whole genome sequence method gave a broader inference of pathogen characteristics.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0168-1605 1879-3460
DOI:	10.1016/j.ijfoodmicro.2021.109245