Abstract: Objective To investigate the distribution and drug resistance of common Gram-negative bacteria causing nosocomial infection in neonatal intensive care unit (NICU) and provide the evidence for use of antibiotic reasonably. Methods The samples of sputum,blood,urine and so on from 1 221 inpatients with suspicious infectious diseases in NICU of the authors' hospital were collected,cultured and isolated during the period from January 2014 to June 2016.Antimicrobial susceptibility testing was carried out using instrumental automated analysis system or Kirby-Bauer Method and their susceptibility data were analyzed according to CLSI standard. Results A total of 235 Gram-negative bacilli strains were isolated from 2 133 specimens and accounted for 56.5%(235/416)in all isolated pathogenic bacterial strains.The top five pathogens were Escherichia coli (29.8%),Klebsiella pneumoniae (28.9%),Pseudomonas aeruginosa (13.2%),Acinetobactor baumannii (6.1%),and Stenotrophomonas maltophilia (5.9%).The isolation rates of Escherichia coli and Klebsiella pneumoniae with positive extended-spectrum beta-lactamases (ESBLs) were 45.7% (32/70) and 39.7% (27/68),respectively.The drug resistance rates of those two bacteria to aztreonam,cefepime,ceftriaxone,cefotaxime,tobramycin and ampicillin were considerably higher (53.1%~100%) but significantly lower to antimicrobial supplemented with beta-lactamases-inhibitors.No strains of Escherichia coli or Klebsiella pneumoniae was found resistant to carbapenem.However,the resistance rates of Pseudomonas aeruginosa,Acinetobactor baumannii and Stenotrophomonas maltophilia to imipenem were 16.1%,21.4%,and 100%,respectively.Besides,all Gram-negative bacilli retained highly susceptibility to ciprofloxacin or levofloxacin. Conclusion The major pathogens in NICU of authors' hospital is Gram-negative bacilli.Regular monitoring and rational evaluation about distribution and drug resistance of bacteria may provide the evidence for empirical application of antimicrobial drugs and contribute to the reduction of antibiotic resistance.

Key words: drug resistance, bacteria, neonatal intensive care unit, antibiotics

摘要： 目的 分析新生儿重症监护病房(NICU)医院感染常见的革兰阴性杆菌分布及耐药情况,为合理使用抗生素提供依据。方法 采集2014年1月-2016年6月本院NICU中1 221例疑患感染性疾病新生儿的2 133份痰、血液、尿等标本,进行细菌培养和分离,用K-B法或仪器自动匹配系统分析致病菌及对抗菌素的耐药性。结果 2 133分标本中共分离革兰阴性杆菌235株,占所检出细菌的56.5%(235/416),位列前5的依次为大肠埃希菌(29.8%)、肺炎克雷伯菌(28.9%)、铜绿假单胞菌(13.2%)、鲍曼不动杆菌(6.1%)和嗜麦芽窄食单胞菌(5.9%)。肺炎克雷伯菌和大肠埃希菌的产超广谱β-内酰胺酶( ESBLs)率分别为45.7%(32/70)和39.7%(27/68),对氨曲南、头孢吡肟、头孢曲松、头孢噻肟、妥布霉素和氨苄青霉素均有较高的耐药率(53.1%~100%),但对加酶抑制剂的抗菌素耐药率低,未发现对碳青霉烯类药物耐药的菌株。铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌对亚胺培南的耐药率分别为16.1%、21.4%、 100%。此外,所检出的革兰阴性杆菌对环丙沙星、左氧氟沙星均保持较低的耐药率(＜20%)。结论 革兰阴性杆菌是本院NICU的主要流行菌,定期进行细菌分布和耐药性监测,可为临床经验用药提供依据,有助于减少耐药菌株的产生。

关键词: 耐药性, 细菌, 新生儿重症监护病房, 抗菌药物