Microbial analysis of street vended ready-to-eat meat around Thohoyandou Area, Vhembe District, Limpopo Province, RSA

Abstract

Background: Street-vended meats are meats that are prepared and sold by vendors on the street. Different types of street vended meats are chicken, pork, beef etc. Street vendors are an integral part of urban economies around the world, offering easy access to a wide range of goods and services in public spaces. Despite these benefits, meat has been well-known as a potential channel for spreading food-borne diseases due to its high-water activity, high protein content, and approximately neutral pH, which create favourable conditions for the multiplication and survival of pathogenic bacteria. Street foods are frequently associated with food-borne illnesses due to their exposure to contamination hence this reduces the quality of these meat. Meat sold by the street vendors could be the source of infectious pathogens and previous studies showed that there is high number of pathogenic bacteria found on meat. The aim of the study was to determine the microbial quality and safety of street vended ready-to-eat meat sold around Thohoyandou Area. Method: A total of 168 samples of street-vended meats consisting of chicken (n=84) and beef (n=84), were collected from the local street vendors around Thohoyandou area. Samples were selected using simple random sampling and purchased meat samples were transferred from vendor packaging into sterile lunch boxes at the point of purchase. The packed samples were placed in a cooler box and immediately transported to the Department of Food Microbiology laboratory, University of Venda for further analysis. Ten grams (10g) of chicken or beef samples were then transferred into a zip lock bags containing 90 ml of peptone buffered water and then cultured in different plate’s containing the selective media: MSA (Oxoid Ltd) was used to culture Staphylococcus aureus, Eosin Methylene Blue (EMB) for E. coli 0157, xylose lysine deoxycholate (XLD) agar, (Oxoid Ltd) for Salmonella, and Sorbitol McConkey (Oxoid Ltd) for Shigella, and then plates were incubated for 24 hours at 37oC. The presumptive colonies were then sub-cultured on Nutrient agar for purification and the plates were incubated at 37oC for 24 hours. The microorganisms were identified using Gram staining and biochemical tests (Catalase, API 20E and Klingler iron Agar Test, and Vitek 2 system). The antibiotic susceptibility was done to determine susceptibility of the microorganisms using antimicrobial Agent such as Ampicillin, Chloramphenicol, Penicillin, Neomycin, Tetracycline, Streptomycin and Amoxicillin). The molecular 5 characterization was done to determine different pathotypes of E. coli using multiplex PCR. Results: Out of 168 samples tested, 32 (19%) were found to be positive for Staphylococcus spp with highest percentage found in cooked chicken meat. The most prevalent staphylococcus species identified in this study were S. xylosus (13.2%) and S. saprophyticus (10.5%). The prevalence of E. coli was found to be 29 (19.3 %) in which highest percentage was found in fried chicken. The antibiotic susceptibility profile of E. coli isolated showed that 100% were Resistant to Ampicillin (AMP), Tetracycline (T) and penicillin (PG) and 100% were susceptible to Neomycin (N). Staphylococcus spp. isolates showed 100% resistance to Ampicillin (AMP) and 100% susceptible to Neomycin(N). The virulence genes ranged from 13,33% to 86,67% with asta, stx1, and eae being the most prevalent. The pathotypes that were detected in this study were EPEC, EHEC, ETEC, EAEC, and EIEC and majority of the isolates were positive for mixed pathotypes (contamination). Conclusion: This current study demonstrated that the microbial quality and safety of street vended meat is inadequate and therefore not acceptable for safe consumption. Therefore, it is essential to monitor the presence of microbes in meat and the detection of these organisms in all beef and chicken meats investigated serves as a warning of foodborne diseases that could be associated with poor personal hygiene, and poor food preparation.