凝固酶阴性葡萄球菌所致血行感染的相关研究

Related Factors of Blood Stream Infection Caused by Coagulase-negative Staphylococci

目的分析凝固酶阴性葡萄球菌（CNS）所致血行感染的相关因素，为临床诊治CNS菌血症提供参考依据。方法对本院2004年1月～2005年5月间血中分离到CNS143例病历进行回顾性分析。结果143例患者中79例为CNS菌血症的确诊病例（55．24%），血培养阳性出现时间20．8h，早于污染菌（31h）（P〈0．01）；病原菌与污染菌对常用抗菌药物敏感性差异无显著性；多瓶血样本均在48h内培养出CNS，全部为菌血症的确诊病例。结论CNS污染率较高，护士在采集血培养标本时，尽可能减少污染；血中分离出CNS时应综合分析临床和实验室资料，做出正确判断后，再用药，避免滥用抗菌药物。

OBJECTIVE To analyze the related factors of blood stream infection caused by coagulase-negative staphylococci （CNS）. METHODS A retrospective analysis of CNS in blood culture from 143 hospitalized patients in General Hospital of PLA from Jan 1 to Oct 31, 2004 was done, and from them true cases of bacteremia were judged and true pathogens or contaminants were identified. RESULTS Seventy of 143 （55. 24%） hospitalized patients were diagnosed as with bacteremia. Most of them suffered from tumor （41）, organs failure （19）, after big operation （9）, immunological system diseases （11） and so on. The rates of CNS （as true pathogens） distribution in clinical wards were as follows： 16/21 from hematological disease ward, 7/11 from pediatric ward, 18/27 from the old patients ward, 13/17 from intensive care unit, 7/16 from surgical department and 18/51 from internal medicine. The mean growth time of contaminants was significantly longer than that of the true pathogens （31.0/20.8 h, P〈0.01）. No significant differences were found between the susceptibility of pathogens and contaminants to antimicrobials. CONCLUSIONS The incidence of CNS contamination in blood culture is very high. So nurses should take measures to reduce the rate of contamination when collecting blood. Doctors should take both the clinical syndrome and laboratory data into consideration when diagnosing so as to reduce the abuse of antimicrobials.