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
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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.