mecA基因与金黄色葡萄球菌感染患者的耐药性研究

Research of mecA gene and drug resistance of Staphylococcus aureus causing infections

目的检测mecA基因在金黄色葡萄球菌(SAU)中的分布,探讨mecA基因与SAU耐药性的关系。方法用琼脂扩散法检测临床分离的112株SAU对常用抗菌药物的耐药性,采用PCR方法检测SAU中的mecA基因,并分析mecA基因和SAU耐药性的关系。结果耐甲氧西林金黄色葡萄球菌(MRSA)59株占52.68%,甲氧西林敏感金黄色葡萄球菌(MSSA)53株占47.32%;MRSA对青霉素G耐药率为100.00%,对红霉素和四环素耐药率分别为69.49%和47.46%,对万古霉素和替考拉宁敏感;MSSA对青霉素G耐药率最高,为88.68%,其次为红霉素和克林霉素,耐药率分别为60.38%和28.30%,对苯唑西林、利福平、万古霉素和替考拉宁敏感;SAU耐药株主要从痰液中分离,神经外科分布最多;mecA基因总阳性率为51.79%,其中MRSA中阳性率为88.14%,MSSA中阳性率为11.32%,mecA基因阳性的MSSA比mecA基因阴性有更高的耐药性。结论 MRSA中mecA基因阳性率极高,在金黄色葡萄球菌的耐药中发挥重要作用。

OBJECTIVE To explore the distribution of mecA gene in Staphylococcus aureus and study the relation‐ship between the mecA gene and the drug resistance of S .aureus .METHODS The drug resistance rates of 112 clini‐cal isolates of S .aureus to commonly used antibiotics were determined by using agar diffusion method ,the mecA gene in the S .aureus strains was detected with the use of PCR ,and the relationship between the mecA gene and the drug resistance of the S .aureus strains was observed .RESULTS The methicillin‐resistant S .aureus （MRSA） accounted for 52 .68% （59 strains） ,and the methicillin‐susceptible S .aureus （MSSA） accounted for 47 .32% （53 strains） .The drug resistance rate of MRSA to penicillin G was 100 .00% ,the drug resistance rates to erythromy‐cin and tetracycline were 69 .49% and 47 .46% ,respectively ,and the MRSA strains were susceptible to vancomy‐cin and teicoplanin .The drug resistance rate of the MSSA to penicillin G was the highest （88 .68% ） ,the drug re‐sistance rates to erythromycin and clindamycin were 60 .38% and 28 .30% ,respectively ,and the MSSA strains were susceptible to oxacillin ,rifampicin ,vancomycin ,and teicoplanin .Most of the drug‐resistant S .aureus strains were isolated from the sputum and mainly distributed in the neurosurgery department .The total positive rate of mecA gene was 51 .79% ,the positive rate of mecA gene in the MRSA strains was 88 .14% ,and the positive rate of mecA gene in the MSSA strains was 11 .32% ;the drug resistance rate of the mecA‐positive MSSA strains was significantly higher than that of the mecA‐negative MSSA strains .CONCLUSION The positive rate of mecA gene is so high in the M RSA strains that it plays an important role in the drug resistance of the S .aureus strains .