The occurence of staphylococcus species in the deboning room of a high-throughput abattoir

Abstract

Meat and meat products are highly perishable foods that frequently present problems with regard to staphylococcal food poisoning because of the considerable handling of the foodstuff that takes place during preparation. Due to the ubiquitous nature of Staphylococcus information pertaining to the prevalence of staphylococci on meat can shed light on the sources of contamination as well as the level of worker and process hygiene. Red meat samples were collected from the deboning room of a high throughput abattoir and exposed to storage temperatures of 5°C and 18°C respectively. During the entire shelf-life study, the total viable counts and Staphylococcus levels remained approximately 60% lower at 5°C than at 18°C. Throughout the shelf-life experiment, the staphylococci counts exceeded the national guideline of 100 CFU.g-1 for meat during exposure to both temperatures with staphylococcal counts peaking at 105 CFU.g-1 at 18°C. Red meat samples prior to vacuum-packaging (directly from the conveyorbelt) as well as bioaerosol samples were furthermore collected and analysed for total viable counts and the presence of Staphylococcus species. The meat was found to be below the microbiological guidelines for raw meat as proposed by the South African Department of Health. The presence of airborne staphylococci counts was 38% compared to 62% · in the sampled meat. The total viable counts from workers' hands and working surfaces were relatively high and well above the national guideline of 100 CFU.cm·2 for working surfaces. The mean staphylococci counts from the surfaces were 19 CFU.cm-2 and these surfaces were found to be moderately contaminated as the levels were above 10 CFU.cm-2 . The following Staphylococcus species were isolated throughout the study: Staphylococcus aureus; S. epidermidis; S. capitis; S. auricularis; S. hominis; S. saprophyticus; S. haemolyticus, S. simulans; S. sciuri; S. intermedius; S. xylosus; S. cohnii cohnii; S. lugdunensis and S. warneri. The presence of the above-mentioned staphylococci pOints to direct and indirect contamination of meat through, amongst others, the meat handlers in the deboning room as the majority of the species are associated with humans. It was deduced that the meat handlers needed to be educated on the importance of proper, safe hygienic working practices as thirteen of the above identified species are toxin-producers. These toxins are predominantly heat stable and are likely to endure the heating process. Because of the adherence ability of this organism special attention should be given to the cleaning and sanitation programmes of the de boning room, especially since some of the Staphylococcus species have been found to be resistant against quaternary ammonium-based cleaning agents.