Epidemic Study of Nasal Carriage of Methicillin-Resistant Staphylococci (MRSA and MRC-NS) in the Volunteers without Apparent Infectious Disease.

耐甲氧西林葡萄球菌（MRSA和MRC-NS）是近年来在未住院的健康人群中发现的一类细菌，是引起医院感染性疾病的重要病原体之一。本研究对社区1036名健康人群进行了MRSA或MRC-NS带菌调查，共检出394例，其中6岁以下儿童、近6个月内使用过抗生素的人群、医务人员及其家属为MRSA或MRC-NS带菌者。在医务人员中，药师携带率最高，215名药师中携带者167名（77.7%），非医务人员带菌率仅为25.6%，进一步调查药师带菌率高的原因，结果发现，以配制抗生素为日常工作的人员有成为携带者的危险，耐药菌株的MIC（MPIPC）均>64 μg/mL，和大约30%的MRC-NS菌株。大部分菌株对大环内酯类、喹诺酮类和磷霉素耐药。PCR检测耐药菌株中mecA-mecRI-mecI基因的存在。大多数梅萨菌株仅缺乏mecI基因，而90%以上的MRC-NS菌株也缺乏mecR 1基因。因此，监测耐药菌株的变化趋势，促进抗菌药物的合理使用，调查药师的工作环境具有重要意义。

Methicillin-resistant Staphylococci (MRSA and MRC-NS) are recently found in healthy persons who have not been hospitalized; however these bacteria are recognized as one of the most important organisms which cause the nosocomial infectious diseases. In this study, we conducted a survey of MRSA or MRC-NS carriage on 1036 healthy person in the community and 394 healthy carriers were found. The healthy carriers were especially found in the population of children under 6 years old, persons who were treated with antibiotics in recent 6 months, medial workers and their family members. In the medial workers, the ratio of carriers was especially high among pharmacists, and 167 carriers of 215 pharmacists (77.7%) were found. Since the ratio of carriers in non-medial workers was only 25.6%, we further investigated the reason of higher carrier ratio in pharmacists, and found that person who prepares antibiotics as their daily work has the risk to be a carrier.The MICs (MPIPC) of drug-resistant strains were >64 μg/mL for all the MRSA strains, and approximately 30% of MRC-NS strains. Most of these strains were also resistant against macrolides, quinolones and fosfomycin. The existence of mecA- mecRI mecI gene in drug-resistant strains was also tested by PCR. Most of MESA strains lack only mecI gene, however more the 90% of MRC-NS strains lack mecR1 gene either.In the near future, the population of aged people and compromised hosts will increase in our community and drug-resistant organisms might cause serious problems. So, it will be important to monitor the tendency of these drug-resistant strains, promote the proper use of antibiotics, and investigate the working environment of pharmacists.