الفهرس 
INTRODUCTION
Biochemical activities of enterotoxigenic staphylococciOnly 14 pages are availabe for public view
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Abstract
Three hundred milk samples which were collected from clinical and subclinical mastitic cases of cows and buffaloes revealed the isolation of 140 staphylococcal isolates that were tested for sugar and mannitol fermentation, urease production, citrate utilization, egg yolk factor production, haemolytic properties and coagulase production to be identified as Staphylococcus aureus. Staphylococcal Enterotoxin Test - Reverse Passive Latex Agglutination (SET-RPLA) is the most commonly used method for the determination of enterotoxins of S. aureus. It has several advantages at present, including high specificity, simplicity and economy. It was found that six strains produced enterotoxin D, whereas, other strains didn’t produce enterotoxins as detected by the SET-RPLA. The relationship between enterotoxigenicity and coagulase production demonstrated that all enterotoxigenic isolates showed positive reaction for coagulase production, but not all coagulase positive staphylococcal isolates were enterotoxigenic. Pathogenic effects of Staphylococcal enterotoxin D (SED) were studied in mice. Seventy mice were injected parenterally with high dose of SED. Administration of the toxin to mice causes lethargy and ruffled fur, diarrhea, and weight loss. In addition, SED showed leukocytic infiltration and different histopathological lesions in liver, spleen, kidney and intestine of mice. The current work aimed to investigate the induction of immunity to SED, as one of staphylococcal enterotoxins, in rabbits as an experimental model. Twenty eight rabbits were divided into seven equal groups, six of them were injected parenterally with SED toxoid originated from 6 different strains for preparation of hyperimmune antiserum against SED and one used as a control. The anti-SED response in serum was determined by agar gel immunodiffusion technique. Results showed that parenterally given SED toxoid induced specific antibodies in serum. Moreover, the serum lysozyme activity was measured in immunized rabbits; significant increase was recorded at one day and subsequently declined at 6 day in all immunized groups in comparison to control group. Furthermore, this study evaluated the IL-6 responses in immunized rabbits by sandwich ELISA to detect visible changes in the IL-6.