金黄色葡萄球菌超抗原在不同人群中的分子特征研究

目的了解菌血症患者血液,医护工作者、非感染性疾病入院患者以及社区健康人群前鼻腔内的金黄色葡萄球菌超抗原基因分子特征。方法用PCR和multiplex-PCR方法对277株菌的毒性休克综合征毒素-1(toxicshock syndrome toxin-1,TSST-1)和肠毒素(staphylococcal enterotoxin,SE)编码基因进行了扩增。结果 277株分离的金黄色葡萄球菌中共有142株(51%)肠毒素基因检测结果为阳性。从医院内各人群组(包括医院菌血症患者组、医护人员组和非感染性疾病入院患者组)分离菌株的阳性率在50%~59%,要比社区健康人群组阳性率(36%)高(χ2=10.86,P<0.05)。医院内各人群组分离株的SE基因主要以A型为主,而社区健康人群组的分离菌株则以D型为优势型别。另外,菌血症患者血液的金黄色葡萄球菌携带基因tsst-1的阳性率要高于其他人群组(χ2=21.91,P<0.01)。结论本研究表明不同人群分离得到的金黄色葡萄球菌超抗原分子特点具有特异性,对临床金黄色葡萄球菌的诊断治疗和流行病学研究具有一定的指导意义。

Study on the Molecular Characteristics of Superantigen in Staphylococcus aureus Isolated from Different Groups of People

Objective To explore the molecuax characteristics of superantigen in Staphylococcus aureus isolated from blood of patients with bacterial sepsis, anterior nasal cavities of heath care workers, hospitalized patients with non- infective dis- eases and healthy people from communities. Methods A total of 277 Staphylococcus aureus strains were tested for presence of genes encoding staphylococcal enterotoxin（SE）and toxic shock syndrome toxin- 1 （TSST- 1 ） by PCR and multiplex PCR. Results SE gene （se） was detected in 51% （142/277） strains. The positive rate of se in isolates from people in hospital （50 % - 59 % ） was significantly higher than that in isolates from people in community （36 % ） （ P 〈 0.05）. The se in isolates from peo- ple in hospital was mainly A type, while that from healthy people in community was mainly D type. The positive rate of tsst - 1 gene in isolates from blood of patients with bacterial sepsis was significantly higher than that in isolates from other groups（ P 〈 0.01 ）. Conclusions The superantigen genes of Staphylococcus aureus isolated from different sources of people have different characteristics. This finding is important for clinical diagnosis, treatment and epidemiological study of Staphylococcus aureus.