2009—2013年血液标本病原菌耐药性监测

Antimicrobial resistance surveillance in the microorganisms isolated from blood specimens:a five-year analysis from 2009 to 2013

目的了解2009—2013年武汉同济医院血液标本病原菌的构成、病原谱的变化及其对常用抗菌药物的耐药情况。方法病原菌按照常规方法进行鉴定和药敏试验。布鲁菌属进行PCR扩增和测序。结果共分离病原菌2 152株(不包括凝固酶阴性葡萄球菌),其中革兰阳性菌761株,占35.4%,革兰阴性菌1 242株,占57.7%。真菌149株,占6.9%。最常见的革兰阳性菌为金黄色葡萄球菌(金葡菌)、屎肠球菌和粪肠球菌;革兰阴性菌为大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌和布鲁菌属。2009年首次分离出1株羊布鲁菌,但2013年增加到50株(其中1株为猪布鲁菌),占当年血液标本分离菌的7.1%。耐甲氧西林金葡菌(MRSA)检出率为54.1%,未检出对万古霉素和利奈唑胺耐药的葡萄球菌。粪肠球菌对氨苄西林和左氧氟沙星耐药率较低,在30%以下;屎肠球菌除糖肽类和利奈唑胺外,对其余抗菌药物的耐药率均在70%以上;大肠埃希菌和肺炎克雷伯菌对哌拉西林-他唑巴坦、阿米卡星、头孢西丁和头孢哌酮-舒巴坦耐药率在15%以下。出现了对碳青霉烯类耐药的肠杆菌科细菌(CRE),以阴沟肠杆菌多见。铜绿假单胞菌对常用抗菌药物保持了较高的敏感性,但鲍曼不动杆菌耐药现象严重,除头孢哌酮-舒巴坦外,对其余抗菌药物的耐药率均在60%以上。结论大肠埃希菌和金葡菌仍是血流感染中最常见病原菌,布鲁菌属检出率逐年增高,应引起重视。此外,血液标本病原菌对常用抗菌药物有不同程度的耐药性,应根据药敏试验结果合理选用抗菌药物。

Objective To investigate the distribution, variability and antibiotic resistance of the pathogen sisolated from bloodstream infections. Methods The bacterial strains were routinely isolated from blood samples and identified. Brucella trains were identified by PCR and gene sequencing. Antimicrobial susceptibility were routinely tested for these isolates. Results A total of 2 152 strains, excluding coagulase negative Staphylococcus, were isolated from blood specimens during the 5 year period from 2009 through 2013. Gram-positive cocci, gram-negative bacilli and fungi accounted for 35. 3% （761/2 152）, 57.7% （1 242/2 152） and 6.9% （149/2 152）, respectively. The top three gram-positive bacteria were S. aureus, E. faecium and E. faecalis. E. coli, K. pneumoniae, P. aeruginosa, A. baumannii, and Brucella were the most frequently isolated gram-negative bacteria. In 2009, only one Brucella melitensis was isolated, but increased to 50 in 2013 （7.1 %）, including one strain of Brucella suis. The prevalence of MRSA was 54. 1% in S. aureus. No staphylococcal isolate was found resistant to vancomycin or linezolid. More than 60% of the E. faecalis isolates still showed low resistance （〈 30%） to ampicillin and levofloxacin. But E. faecium strains were highly resistant to most antibiotics （〉70%） except glycopeptides and linezolid. E. coli and K. pneumoniae isolates displayed low resistance rate （〈15%） to piperacillin-tazobactam, amikacin, cefoxitin and cefoperazone-sulbactam. Carbapenem-resistant Enterobacteriaceae strains were identified, especially in Enterobacter cloacae. P. aeruginosa isolates were still susceptible to the commonly used antibiotics, but A. baumannii isolates were highly resistant （〉60% resistant） to all the commonly used antibiotics except cefoperazone-sulbaetam. Conclusions Our five-year surveillance data indicated that E. coli and S. aureus were still the most common pathogens in blood stream infections. Attention should be paid to the increasing prevalence of Brucella in blood stream infections. Various levels of antibiolic resistance are found in the pathogens of blood stream infections. Antibiotics should be prescribed reasonably according to local susceptibility testing data.