Antimicrobial Resistance Profiles of Salmonella Isolates on Chickens Processed and Retailed at Outlets of the Informal Market in Gauteng Province, South Africa.

Thelma M Mokgophi,Nomakorinte Gcebe,Folorunso Fasina,Abiodun A Adesiyun

doi:10.3390/pathogens10030273

Abstract

The study determined the antimicrobial resistance profiles of Salmonella on chickens processed and retailed at outlets of the informal markets in Gauteng province, South Africa. The study also investigated the relationship of antimicrobial resistant Salmonella to the source and type of samples and their serotypes. Carcass swabs, cloacal swabs and carcass drips were randomly collected from each of 151 slaughtered chickens from six townships. Isolation and identification were performed using standard and polymerase chain reaction (PCR) methods. The disc diffusion method was used to determine the resistance of Salmonella isolates to 16 antimicrobial agents and PCR to determine their serovars. Ninety-eight (64.9%) of the 151 chickens were contaminated with Salmonella of which 94.9% (93/98) were resistant serovars. The frequency of antimicrobial resistance of Salmonella isolates was high to erythromycin (94.9%) and spectinomycin (82.7%) but was low to ciprofloxacin (1.0%) and norfloxacin (1.0%) (p < 0.05). All 170 isolates of Salmonella tested exhibited resistance to one or more antimicrobial agents and the frequency varied significantly (p < 0.05) across the townships, the type of samples and the serovars. The prevalence of multidrug resistance (MDR) in Salmonella was 81.8% (139/170). Our findings pose zoonotic, food safety and therapeutic risks to workers and consumers of undercooked, contaminated chickens from these outlets.

Highlights

Salmonella spp. are known to cause high morbidity, mortality and economic losses in the poultry industry [1,2,3,4]
A total of 170 isolates of Salmonella that were recovered from chicken carcass swabs, cloacal swabs and carcass drips were identified and confirmed using conventional and Pathogens 2021, 10, 273
Isolates of Salmonella in chickens processed and retailed at outlets of the informal market in Gauteng province are likely to be indicative of potential zoonotic, food safety and therapeutic implications posed to workers at the outlets and consumers of improperly cooked Salmonella-contaminated chicken meat

Summary

Introduction

Salmonella spp. are known to cause high morbidity, mortality and economic losses in the poultry industry [1,2,3,4]. In an effort to prevent, control or eradicate potential infection by Salmonella spp. and other pathogens in the poultry industry, antimicrobial agents are used for prophylaxis, therapy and as growth promoters [9,10,11,12,13]. The use of antimicrobial agents is strictly controlled or banned for specific reasons in poultry through the enforcement of existing laws and regulations [5,6,14]. In most developing counties including South Africa, laws exist to control the use of antimicrobial agents, there are challenges in their enforcement thereby resulting in their inappropriate use (overuse or abuse) [15,16]. In addition to the unregulated use of antimicrobial agents in South Africa, the Fertilizers, Farm Feed, Agricultural and Stock

Methods

Results

Discussion

Conclusion