Abstract
Beef carcass evaluation is generally the basis for judging the commercial value of the livestock and is consequently one of the most common quality control tests carried out in the meat industry. In the current study, sixty swabs were taken from the outer surface of neck and groin (30 of each) of freshly dressed beef carcasses taken from three local slaughterhouses located in El-Bagour, El-May and El-Shohada provinces of Menoufia governorate, Egypt. Swabs were microbiologically examined; the results revealed that groin samples had significantly (P≤0.05) lower contamination levels than that of neck samples. In addition, samples that were collected from El-May’s abattoir revealed the highest bacterial counts, followed by El-Bagour and El-Shohada, respectively. Regarding to detection of some pathogenic bacteria in the examined swab samples, S. aureus was the most detected bacteria, followed by Salmonella spp. and E. coli with total incidence 23.3, 18.3 and 15.0, respectively. However, equal number of S. aureus isolates was obtained from neck and groin samples, groin samples showed higher incidence of Salmonella and E. coli than those of neck samples. In addition, staphylococcal enterotoxins were investigated in the contaminated samples. Results revealed that all of the examined samples had enterotoxin type A only. Moreover, E. coli isolates were serotyped into O103:H2, O146:H21 and O117:H4; out of which, three strains were molecularly examined for their Shiga toxin types 1 (stx-1) and 2 (stx-2) genes; where, stx-1 was detected in 66.7% of the examined strains, while stx-2 was not detected in any of the examined isolates. On the other hand, Salmonella strains were serotyped into S. Enteritidis, S. Montevideo, S. Tsevie, S. Typhimurium and S. Shangani were the detected serotypes. Salmonella Typhimurium was detected in higher incidence than the other detected strains. So, regular monitoring of beef carcasses microbiological evaluation, and application of strict hygienic measures are recommended.

Key words: Hygienic quality, Slaughterhouse, Egypt