The distribution of Staphylococci in bioaerosols from red-meat abattoirs

The quality and shelf-life of perishable foodstuffs can be reduced by high concentrations in the processing environment of bioaerosols consisting of spoilage microbiota. A lack of documented literature on the distribution of such bioaerosols has, however, led to the underestimation of their impact. In the study reported here, the deboning rooms of selected South African red-meat abattoirs were investigated for airborne concentrations of staphylococci; the authors studied the distribution of Staphylococcus species in general, as well as the coagulase types of Staphylococcus aureus in particular. Average staphylococci bioaerosol concentrations varied considerably among the abattoirs investigated, with Abattoir B having the highest counts (3 x 10(2) CFUs/m3) and Abattoir A having the lowest (7.6 CFUs/m3). There was a significant link between bioaerosols and microbial loads from red meat in the same environment. The recorded levels were, however, well below the recommended maximum limits for bioaerosols suggested by various international and governmental authorities. Staphylococcus xylosus and S. saprophyticus were found to be the most abundant species in the air of the deboning rooms, while among S. aureus coagulase types, Type III and Type VIII were predominant. On the basis of the ecology of the bacterial groups, the authors suggest probable sources of staphylococcal bioaerosols and propose strategies that could be developed for red-meat abattoirs to reduce the levels of airborne pathogens.