Abstract
Background:
The importance of this research is to address the significant concern regarding the presence of (Escherichia coli), which is p roducing cytotoxic Vero O157:H7 in meat products, and the lack of studies that is occurred in ourcountry on the level of meat contamination with E. coli, which is considered dangerous, and it has implications for the health of consumers of red and white meat.

Aim:
To detect the presence of E. coli, which produces cytotoxin Vero toxin O157:H7 in red and white meat that is consumed in local markets, and the effects of some preservatives.

Methods:
This study was conducted in the microbiology and polymerase chain reaction at the Faculty of Veterinary Medicine, Hama University. One hundred and twenty random red and white meat samples that were consumed in local markets in Hama were collected to detect E. coli, which produces cytotoxic Vero toxin, as follows: Twenty samples of each beef, goat, sheep, camel, broiler and fish meat, which are available in the markets and widely consumed. Two hundred and fifty grams of each type of meat sample were collected. The samples were placed in sterile nylon bags to prevent contamination and transported to the laboratory in special thermal containers until the necessary tests were conducted.

Results:
The analysis of broiler meat samples showed the presence of E. coli that produces cytotoxic Vero toxin O157:H7 in 65% of the samples. The fish meat samples revealed that 10% contained E. coli producing the toxic Vero toxin for O157:H7 cells, with 50% of those strains tested for bacterial culture. Red meat samples indicated that 55% of sheep meat contained E. coli producing the toxic Vero toxin for O157:H7 cells, with 10% of the strains isolated. For beef, 10% of the samples contained E. coli producing the toxic Vero toxin for O157:H7 cells, in 15% of the strains tested. Overall, 60% of the samples had E. coli producing Vero toxin for O157:H7, with 10% confirmed by PCR. Additionally, 75% of the samples tested by bacterial culture contained E. coli producing Vero cytotoxic toxin.

Conclusion:
The presence of this E. coli bacteria and its detection by PCR test in white and red meat carcasses poses a significant risk to public health, which is evidence of the poor health status of meat markets.

Key words: E. coli; White and red meat; PCR; Public Health.