Detection of vancomycin-resistant MRSA in oral cavity of dental patients

耐甲氧西林金黄色葡萄球菌（MRSA）出现于20世纪80年代，是医院的主要临床和流行病学问题。最近，世界各地报道了万古霉素耐药MRSA的出现。在牙科诊所，种植是现在流行的方法，以治疗牙周病患者。这种侵入性治疗会增加口腔细菌感染的风险。本项目研究了口腔患者口腔中万古霉素耐药MRSA的分布情况，在项目的第一年，研究者利用mecA、femA和IS431探针建立了MRSA的PCR检测体系。mecA基因的PCR检测可以揭示葡萄球菌是否耐甲氧西林。采用葡萄球菌选择性110琼脂平板对口腔健康患者的口腔拭子样本进行检测。大多数菌株显示白色菌落，表明大多数分离株为凝固酶阴性菌株。 ...更多信息 葡萄球菌。出现的菌落中小于1%是形成黄色菌落的S。金黄色。然而，超过7%的凝固酶阴性葡萄球菌是mecA阳性。结果表明，健康人口腔中MRSA的检出率可忽略不计，而耐甲氧西林凝固酶阴性葡萄球菌在人口腔中的定植率较高。在身体残疾的牙科患者的口腔中进行了类似的研究。mecA阳性葡萄球菌的比例明显高于健康口腔患者。结果提示，残疾人口腔中存在耐甲氧西林葡萄球菌定植。mecA阳性葡萄球菌的广泛分布可能导致了耐万古霉素的细菌在口腔和肠道中的广泛传播，但由于研究者从牙科患者中分离到的MRSA克隆不到10个，因此无法得出关于万古霉素耐药性的确切结论。在这些MRSA的克隆中，没有发现万古霉素耐药。

Methicillin-resistant Staphylococcus aureus (MRSA) emerged in the 1980s as a major clinical and epidemiologic problem in hospitals. Very recently, emergence of vancomycin-resistance MRSA is reported around the world. In dental clinics, implantation is now popular method in order to treat patients with periodontal diseases. Such invasive treatments will increase the risk of infection by oral bacteria. In this project, the investigator study the distribution of vancomycin-resistant MRSA in oral cavity of dental patients.In the first year of this project, the investigator has established the PCR detection system for MRSA by using mecA, femA and IS431 probes. PCR analysis for mecA of isolated staphylococci will reveal whether the isolate is methicillin-resistant or not. Oral swab samples from healty dental patients were examined by using staphylococcus-selective Staphylococcus 110 agar plates. Most of them showed white colonies indicating that most of the isolates were coaglase-negative st … More aphylococci. Less than 1 % of the appeared colonies was the yellow-colony forming S. aureus. However, more than 7% of the coagulase-negative staphylococci were mecA-positive. These results suggested that whereas MRSA in oral cavity of healty human is negligible, a number of methicillin-resistant coaglase-negative staphylococci colonize in human oral cavity. Similar study was performed in oral cavity of physically handicapped dental patients. The percentage of mecA-positive staphylococci was significantly higher than that of healty dental patients. These results suggested that methicilin-resistant staphylococci colonize in oral cavity of handicapped persons. Taken together, the wide distribution of mecA-positive staphylococci may contribute the spread of antibiotics-resistance in many other oral and enteric bacteria.Since the investigator isolated less than 1 0 clones of MRSA from dental patients, no solid conclusion could obtained about the vancomycin-resistance. In these clones of MRSA, no vancomycin-resistant was found. Less