prevalence of salmonellae in meat and meat products

The number and types of salmonellae that were found in local and imported frozen meats and some meat products are reverted. Contamination of beef meat with salmonellae was heavier in imported frozen meat [30% positives] than, in samples of raw meat of local origin [21%]. Forty percent of sausage samples and 20% of minced meat samples were salmonellae positive, while only 10% of liver samples were positive. The presence of salmonellae in the kofta and kabab samples before but not after grilling, may be attributed to the heat treatment received by these products during processing. The recovery rate of salmonellae was higher in samples taken in the summer than in the winter. Salmonella typhimurium [causing food poisoing] was the most predominant serotype in the meats, followed by S, enteritidis and S. typhi [causing typhoid fever]. S. choleraesuis was isolated only from imported meats

Some factors affecting salmonellae growth in meat

The antimicrobial effect of onion, garlic, NaC1, and Iraqi spices on S. typhimurium and other organisms present in meat, as well as their microbial flora were studied. Fresh onion and garlic samples gave the highest counts for both total viable and coliforms. Few contaminants were recovered from the salt and spice samples. Salmonella was not recovered from any of the ingredients. The cooked meat treated with garlic resulted in greater inhibition of salmonellae growth than that in the onion treated sample. The inhibition rate reached, after storage for 7 days, was 85% with garlic and 21. 43% with onion. Iraqi spices were more effective in inhibiting the bacterial growth, whilst absolutely no growth occurred in the presence of salt, By increasing the concentration of the ingredients to 10% by weight, no significant change in growth curves of the organism was observed. When the food ingredients were added to the raw meat inoculated with. S. typhimurium, lesser inhibition was detected. The total bacterial counts, as well as the coliforms, were affected in a similar way as that of S. typhimurium in the presence of the different food ingredients. The effect of room, refrigeration and deep freeze storage temperatures on the growth of salmoneliae in meat was also studied. The initial viable counts of S. typhimurium was greatly increased at the room temperature [c. 23§C]. The maximum count reached in 4 days was 8.3 x 10§. No growth took place either at [3§C] or at [-8§C]. The freezer temperature eliminated more than 90% of the total salmonellae count in the meat. However, the organism could survive for more than one month

Interactions between salmonella typhimurium and other meat microorganisms

The competitive effect of certain organisms, that generally contaminate meat, on the growth of S. typhimurium was investigated. The test organisms were E. coli, Lactobacillus plantarum and certian species related to the genera Bacillus, Micrococcus and Pseudomonas. E. coli was found to exhibit antibacterial activity against S. typhimurium. Micrococcal organisms and L. plantarum slightly limited its growth rate. This was observed in meat as well as in the broth medium. Great stimulation of S. typhimurium growth was detected when grown together with the Pseudomonas sp. Lesser stimulatory effects were obtained for the Bacillus sp, The proteolytic activity of the organisms seemed to be responsible for their stimulatory effects