Isolation of corynebacterium species from retail mutton and lamb in the North West Province, South Africa

Abstract

Corynebacterium species occur as part of the normal flora of animals and humans and there is very little information on the diversity and host range of these pathogens. Despite this, some Corynebacterium species have been reported to cause infections in both animals and humans. Infections usually result from the consumption of contaminated food products such as meat and milk as well as contact with infected animals. The aim of study was to isolate, identify and characterize Corynebacterium species from retail meat products obtained from some supermarkets in the North West Province, South Africa. A total of 25 mutton and lamb meat samples were purchased from some supermarket and butcheries in the North West Province, South Africa and bacteria was isolated using Colombia agar supplemented with 5% (w/v) bovine blood. Seventy five presumptive Corynebacterium isolates were obtained based on colonial morphology and these isolates were screened for characters of Corynebacterium species. Amongst these, 67 isolates were catalase positive while 54 were Gram positive rods. Twenty four representative isolates were not able to utilize urea and ferment glucose and maltose respectively. However 19 (79.2%) of these isolates were able to utilize nitrate and33% were positively identified as Corynebacterium species using API Coryne assay. Eleven percent of the isolates were positively identified as Corynebacterium species by 16S specific rRNA PCR analysis. From these results it was evident that Corynebacterium species were present in the raw meat products and the meat products could pose severe health risks to consumers, especially individuals who are immuno-compromised. This therefore amplifies the need to implement strict measures that limit the transmission of these pathogens through the food chain to consumers. Moreover, constant assessments of the health risks associated with contaminated food products in the South African market should be performed on routine basis.