Prevalence, serovars and factors associated with Salmonella contamination of chicken carcasses sold in outlets of the  informal  market in Gauteng Province, South Africa

Salmonella  has been linked to many food-borne 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 outlets of the informal markets 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% (44/151), 27.2% (41/151) and 43.7% (66/151), respectively and the differences were statistically significant (p=0.004).  Only five factors  (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 typable using a limited molecular PCR technique and nine serovars were identified.  The predominant Salmonella enterica serovars were Bovismorbificans (31.0%), Enteriditis (7.5%), Hadar (6.7%). The five important factors found to be significantly associated with the isolation of Salmonella   at these outlets offer invaluable opportunities for the reduction of Salmonella contamination.  There is a need for further investigation of the probable causes for the predominant isolation of serovar Bovismorbificans  in chicken and its potential implications for human infections in South Africa.  It is concluded that chicken purchased from the informal market in Gauteng province can be a source for  salmonellosis in humans if improperly cooked prior to consumption.