الفهرس 
Cover Page Title in EnglishOnly 14 pages are availabe for public view
 |  | from | 79 |  |  |
| | | from | 79 | | |
Abstract
This work was carried out for identification and studying some factors of the pathogenic determinants of S.aureus isolated from imported frozen meat from different origins like (Brazil, Australia,USA and India) the samples were collected from different supermarkets at Alexandria governorate and Alexandria port .different cuts were collected either from forequarter or hindquarter , from beef and buffalo meat .
S.aureus were isolated using Baird Parker agar media , Mannitol Salt agar media and identified using some of the biochemical tests , then finally random selection for 10 samples for detection of some of S.aureus enterotoxin coding genes.
The results are summarized in the following points :
• The incidence of pathogenic Staphylococci isolated from imported frozen meat was 59 isolates (29%)
• Bacteriological examination of 201 meat samples yielded 59 isolates , with an incidence of (29.35%) were suspected to be Staphylococci since these isolates showed pigmentation characteristics and were gram-positive cocci .
• 48 isolates with an incidence of (81%) out of the 59 suspected isolates were positive for coagulase activity using the tube coagulase test (TCT).
• Results showed the ability of TCT on the isolates to detect the presence of pathogens . The test is inexpensive and easy to perform with limited laboratory facilities.
• S.aureus was tested for in-vitro differentiation between Human origin and animal origin strains using different types of blood agar media (sheep, horse, rabbit and human).the result showed that 42 isolates (87%) of human origin and 6 isolates (13%) of animal origin.
• PCR technique was used as confirmatory, rapid, sensitive and specific tool foto detect S.aureus enterotoxin A,B,C and D (SEA,SEB,SEC and SED) coding genes in ten S.aureus bacteriologically positive samples. The technique use was PCR using specific primers for S.aureus SEA,SEB,SEC and SED, which are some of the pathogenic determinants of S.aureus isolated from imported frozen meat.
• Two types of PCR technique were used in this study simplex for SEA and SEB coding genes separately and multiplex PCR which save time as it was used for detection both SEC and SED coding genes in only one reaction and so it is more preferable to be used in practical works to save time consumed by two or more reactions by simplex PCR.
Conclusion :
1. S.aureus is highly prevalent in frozen imported meat .
2. Frozen meat may be a very dangerous source of food poisoning to human by Staphylococcus aureus .
3. Contamination by human hand and nasal discharge may play a significant role for food poisoning by S.aureus due to consumption of frozen meat.
4. In consideration of time money consumed in traditional bacteriological examination methods and PCR techniques , the results confirm the ability of TCT for detection of pathogenicity of S.aureus as a simple, non-expensive and easy to confirm system.
5. In consideration of time and accuracy for detection of enterotoxin coding gene it is definitely found that multiplex PCR technique is more rapid than simplex PCR technique.