Prevalence, Serovars, and Factors Associated with Salmonella Contamination of Chicken Carcasses Sold in Outlets of the Informal Market in Gauteng Province, South Africa

Abstract

ABSTRACT Salmonella has been linked to many foodborne illnesses and epidemics in both humans and animals. This cross-sectional study determined the prevalence, serovars, and factors associated with Salmonella contamination of chickens slaughtered in informal market outlets in Gauteng Province, South Africa. A total of 151 chicken carcasses were randomly collected from 47 outlets. Standard bacteriological and molecular methods were used to isolate, identify, and determine the serovar of Salmonella isolates. The prevalence of Salmonella in carcass swabs, cloacal swabs, and carcass drips was 29.1% (44 of 151), 27.2% (41 of 151), and 43.7% (66 of 151), respectively, and the differences were statistically significant (P = 0.004). Only 5 (township locations of outlet, throughput, carcass evisceration, location of carcass for sale, and outlet sanitation) of 10 factors investigated for the contamination of carcasses by Salmonella were statistically significantly (P < 0.05) associated with the isolation of Salmonella. Of the 268 isolates of Salmonella, 157 (58.6%) were typeable using a limited molecular PCR technique, and nine serovars were identified. The predominant Salmonella enterica serovars were Bovismorbificans (31.0%), Enteritidis (7.5%), and Hadar (6.7%). The five important factors found to be significantly associated with the isolation of Salmonella at these outlets offer opportunities for the reduction of Salmonella contamination. There is a need for further investigation of the probable causes of the predominant isolation of Salmonella serovar Bovismorbificans in chickens and its potential implications for human infections in South Africa. It is concluded that chickens purchased from the informal market in Gauteng Province can be a source for salmonellosis in humans if improperly cooked before consumption. HIGHLIGHTS