Antimicrobial resistance of bacterial flora associated with bovine products in South Africa

• Published in: Journal of food protection 1999-06, Vol.62 (6), p.615-618
• Main Authors: Manie, T, Brozel, V.S, Veith, W.J, Gouws, P.A
• Format: Article
• Language: English
• Subjects: Abattoirs; Animals; bacteria; Bacteria - drug effects; Bacteria - isolation & purification; Bacteria, Aerobic - drug effects; Bacteria, Aerobic - isolation & purification; beef; Biological and medical sciences; Cattle; dairy products; drug resistance; Drug Resistance, Microbial; Enterobacteriaceae; Enterobacteriaceae - drug effects; Enterobacteriaceae - isolation & purification; food contamination; Food industries; food processing; Fundamental and applied biological sciences. Psychology; gentamicin; MAR pathogenic bacteria; Meat - microbiology; Meat and meat product industries; meat products; methicillin; microbial contamination; Microbial Sensitivity Tests; Milk - microbiology; Milk and cheese industries. Ice creams; oxacillin; pasteurized milk; selection pressure; South Africa; Staphylococcus; Staphylococcus - drug effects; Staphylococcus - isolation & purification; streptomycin; tetracycline; vancomycin
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-62.6.615

The administration of subtherapeutic doses of antibiotics to livestock introduces selective pressures that may lead to the emergence and dissemination of resistant bacteria. This study determined the antibiotic-resistance spectra of the microbial flora found on freshly slaughtered and retail beef and in unpasteurized and pasteurized packaged milk Staphylococci, Enterobacteriaceae, and isolates from total aerobic plate counts were tested for resistance to vancomycin, streptomycin, methicillin, tetracycline, and gentamicin using the disc diffusion susceptibility test and resistance to penicillin was determined by using oxacillin. A larger proportion of resistance to most antibiotics, except for vancomycin, was displayed by isolates from abattoir samples. The incidence of multiple antibiotic resistance (MAR) pathogenic bacteria is also higher in the abattoir. Resistance genes lost because of lack of selective pressure or resistant flora being replaced by more sensitive flora during processing is the reason for the lower incidence of MAR pathogenic bacteria among retail samples. These resistant bacteria can be transferred to humans through the consumption of rare or raw beef and unpasteurized milk, thus rendering the resultant food-related infections difficult to treat. The present findings clearly demonstrate that antibiotic-resistant bacteria in beef and milk pose a serious problem in South Africa.