The initial microflora of fresh meat and poultry generally consist of Staphylococcus, Micrococcus, Coryneforms, Flavobacterium, Pseudomonas, Moraxella, Acinetobacter, Alkaligenes, and Enterobacteriaceae. Pseudomonas, Moraxella, and Acinetobacter will become dominant flora under refrigerated, aerobic storage conditions. These organisms are psychrotrophic and thus grow well at typical refrigeration temperatures ranging from 0 to 7 °C. The mesophilic organisms will not grow at these temperatures and are outcompeted by the psychrotrophs. When fresh and poultry products are stored under refrigerated vacuum packaging (VP) or modified atmosphere packaging (MAP), the dominant spoilage microorganisms will lactic acid bacteria (i.e., Carnobacterium, Lactobacillus, Leuconostoc, and pediococcus) and Brochothrix thermosphacta. These organisms grow well at refrigerated temperature under oxygen-limited conditions and will dominate over mesophiles and aerobic psychrotrophs.
Temperature abuse of fresh meat and poultry products may occur at any point in the distribution chain. When aerobically stored meat and poultry are temperature abused, both mesophilic and psychrotrophic bacteria will be present as part of the spoilage microflora. Under moderate abuse conditions (10- 20 °C), Pseudomonas, Moraxella, and Acinetobacter will be dominant with lower levels of Enterobacteriaceae, Micrococcus and B. hermosphacta. Alternatively, when sever abuse is encountered (20 -30°C), Enterobacteriaceae and Staphylococci may comprise a larger proportion of the microflora. When meat and poultry stored under oxygen-limited conditions experience moderate temperature abuse, the microflora is commonly dominated by Enterobacteriaceae with lower levels of lactic acid bacteria, whereas severe temperature abuse results in a microflora consisting principally of Closteridium with lower levels of lactic acid bacteria and Enterobacteriaceae.