ABSTRACT
Despite advances in disease prevention and food materials technology, food borne diseases are still a major problem in both developed and developing countries. Moreover, meat plays a key role in transfer of bacteria, especially "Zoonotic" to humans. Therefore, we decided to investigate the outbreak of pathogenic bacteria such as Salmonella,Campylobacter. Yersinia and Aeromonas in red meat and chicken offered as packed and unpacked in areas under the authority of Tehran university of medical sciences 630 samples including 315 raw chicken meat and 315 raw red meat samples were collected and tested for a period of one year from July, 2004 to August.2005. Samples were collected from shops selling packed meat and chicken as well as shops selling unpacked meat and chicken in different parts of the south of Tehran The methods used for the laboratory investigation were based on Iranian National Standard Procedure No. 2394. Of the 630 samples of chicken and meat, 183 samples [29%] were contaminated. 49.2 percent of the contaminated samples were chicken meat and 8.9 percent were red meat. From the total, 71 samples were contaminated with salmonella [11.3%], 68 samples with Campylobacter [10.8%], 26 samples with Yersinia entrocolitica [4.1%] and 18 samples with Aeromonas [2.9%]. In red meat samples, microbial contamination was observed in 4.9% of packed and 10.3 percent of unpacked samples. Contamination rate of chicken samples was higher including 59.3% of packed and 45.7% of unpacked chicken samples. The observed difference between the remitting samples of packed and unpacked chicken was statistically significant. [P< 0.05] Our results indicated that although the centers selling packed and unpacked red meat from south of Teheran showed different microbial contamination rate, the differences were statistically insignificant. [P> 0.05]