新生儿败血症病原菌及其耐药性六年的变迁

目的了解新生儿败血症病原菌、耐药情况及其变化趋势，为临床抗感染治疗提供依据。方法回顾性分析2009年1月—2014年12月某院新生儿科收治的新生儿败血症血培养分离病原菌及其药敏结果，比较2009—2011年与2012—2014年病原菌分布及其耐药性变化。结果 新生儿败血症患者共培养病原菌259株，其中革兰阳性菌175株（67.57%），革兰阴性菌65株（25.10%），真菌19株（7.33%）。前后三年均以凝固酶阴性葡萄球菌(CNS)为主，其次为肺炎克雷伯菌；产超广谱β-内酰胺酶（ESBLs）菌株的构成比由10.56%升高至15.38%，真菌构成比由4.93%上升至10.25%；前后三年病原菌构成比较，差异无统计学意义（P＞0.05）。前后三年主要病原菌对常用抗菌药物的耐药率比较，差异均无统计学意义（均P＞0.05）；革兰阳性菌对万古霉素、替考拉宁及利奈唑胺100.00%敏感，但CNS中有82.28%~88.33%耐甲氧西林，金黄色葡萄球菌有75.00%~100.00%耐甲氧西林；肺炎克雷伯菌及大肠埃希菌对第三代头孢菌素类抗生素的耐药率达42.86%~86.67%，对头孢哌酮/舒巴坦的耐药率分别从17.39%、14.29%上升至33.33%、30.00%，未检出对美罗培南及亚胺培南耐药的菌株。白假丝酵母菌对氟康唑的耐药率从20.00%上升至50.00%，所有检出的真菌对两性霉素B仍保持敏感。结论CNS是新生儿败血症的主要致病菌，其次为肺炎克雷伯菌，真菌感染比例有所增加，临床应根据血培养及药敏结果合理使用抗菌药物。

Change in pathogens and antimicrobial resistance in neonatal septicemia during 6 years

ObjectiveTo understand the pathogens causing neonatal septicemia, as well as changing trend of antimicrobial resistance, and provide evidence for clinical anti infection treatment. MethodsResults of blood culture and antimicrobial susceptibility testing of pathogens from neonates with septicemia who were admitted to the department of neonatology of a hospital from January 2009 to December 2014 were analyzed retrospectively, distribution of pathogens and antimicrobial resistance between 2009-2011 and 2012-2014 were compared. ResultsA total of 259 strains were isolated from blood specimens, gram positive bacteria, gram negative bacteria, and fungi were 175(67.57%), 65(25.10%), and 19（7.33%）respectively. Coagulase negative staphylococcus (CNS) was the main pathogen during 6 years, followed by Klebsiella pneumoniae(K. pneumoniae); the constituent ratio of the extended spectrum β lactamase (ESBLs) producing strains increased from 10.56% to 15.38%, constituent ratio of fungi increased from 4.93% to 10.25%（P＞0.05）; The sensitivity of gram positive bacteria to vancomycin, teicoplanin, and linezolid were all 100.00%, 82.28%-88.33% of CNS and 75.00%-100.00% of Staphylococcus aureus were methicillin resistant; the resistance rates of K. pneumoniae and Escherichia coli to the third generation cephalosporins were 42.86%-86.67%，to cefoperazone/sulbactam increased from 17.39% and 14.29% to 33.33% and 30.00% respectively, meropenem and imipenem resistant strains were not found. Resistance rate of Candida albican to fluconazole increased from 20.00% to 50.00%，all detected fungi remained sensitive to amphotericin B. ConclusionCNS are the major pathogens in neonatal septicemia, followed by K. pneumoniae, constituent ratio of fungal infection has increased. Antimicrobial agents should be chosen according to blood culture and antimicrobial susceptibility testing results.