The study with rapid detection for the toxins of Methicillin-resistant Staphylococcus aureus and with the action of the toxins

1.建立了检测葡萄球菌肠毒素和TSST-1基因的PCR方法。本文设计了5对引物（entA-D和tst），并对临床分离的金黄色葡萄球菌进行了检测。A、B、D和tst的PCR和免疫学检测结果基本一致。而免疫学方法检测不到肠毒素C的金黄色葡萄球菌，PCR检测到肠毒素C基因。术后MRSA肠炎致病菌毒型以entA、C、tst为主.接着，用从临床样品（痰和胃液）直接提取的葡萄球菌DNA进行mec A和tst的PCR。检测MRSA最小CFU的灵敏度为mec A约800 CFU，tst约200 CFU。新西兰白色家兔注射TSST-1。监测他们的动脉血压，并检查他们的白色血细胞计数。观察到动脉血压下降和白色血细胞计数减少。但生物测定法检测不到血清TNF和IL-1.我们检测了在各种条件下（Mo、Mo + T细胞、Mo + IL-2、Mo + INF γ、单核细胞）用TSST-1或LPS刺激的人分离的单核细胞（Mo）的TNF产生。各培养上清中TNF水平无明显差异。

1. We have established the method for detection of genes for staphylococcal enterotoxins and TSST-1 by the polymelase chain reaction (PCR). Five pairs (ent A - D and tst) of oligonucleotid primers were made and tested with clinical isolated strains of S.aureus. The results using PCR and immunological method are almost same within ent A, B, D and tst. But ent C genes were detected by PCR with the strain of S.aureus whose enterotoxin C were not detected by immunological method. The toxical type of most causative strains of post operative MRSA enteritis was ent A, C and tst.2. Next, PCR for mec A and tst was performed with directly extracted staphylococcal DNA from clinical samples (sputum and gastric juice). The sensibilitys for the detection of minimal CFU of MRSA were about 800 CFU for mec A and about 200 CFU for tst.3. New Zealand white Rabbits were injected with TSST-1. Their arterial blood pressure were monitored and their white blood cell count was examined. The decline of the arterial blood pressure and decrease of white blood cell count were observed. But we could not detect serum TNF and IL-1 with bioassay.4. We examined TNF production from human isolated monocyte (Mo) with stimulation of TSST-1 or LPS under various conditions (Mo, Mo + Tcell, Mo + IL-2, Mo + INF gamma, mono nuclear cells). There was no significant deferenciation of TNF level between each culture supernatant.