儿童重症监护病房2004至2009年下呼吸道常见革兰阴性杆菌感染分布与耐药监测

Common gram-negative bacilli lower respiratory tract infection in PICU： analysis of pathogens and drug resistant pattern from 2004 to 2009

目的探讨成都市儿童医院重症监护病房（PICU）痰标本分离的常见革兰阴性杆菌感染的菌群分布与耐药性变迁。方法对2004年1月至2009年12月临床收集的合格痰标本分离出的常见革兰阴性杆菌耐药性进行回顾性分析，并比较2004至2006年、2007至2009年两个时段的菌群分布及耐药性变化。所有标本按标准微生物学方法进行定量、定性培养。连续两次培养，同一优势菌株为致病菌；并对所有鉴定所用试剂及药敏分析所用抗菌药物纸片进行质量控制。结果6年共分离出革兰阴性杆菌598株，两个时段前5位均依次为大肠埃希菌167株（27．93％）、肺炎克雷白杆菌109株（18．23％）、阴沟肠杆菌93株（15．55％）、鲍曼不动杆菌64株（10．7％）、铜绿假单胞菌43株（7．19％）。对亚胺培南、阿米卡星、哌拉西林／他唑巴坦较为敏感，而耐药率最高的药物为阿莫西林、氨苄西林、多种头孢菌素等。除铜绿假单胞菌、鲍曼不动杆菌外，未发现耐亚胺培南的革兰阴性菌株；2007至2009年肺炎克雷白杆菌及大肠埃希菌产超广谱β-内酰胺酶菌株检出率较2004至2006年明显上升。结论与2004至2006年相比，2007至2009年本院PICU常见革兰阴性杆菌感染耐药率呈上升趋势，及时监测PICU病原菌耐药趋势变化对指导危重患儿合理用药致关重要。

Objective To study common Gram negative bacterial pathogens and their drug resistant pattern in sputum isolates from patients in pediatric intensive care unit （PICU） of Chengdu children＇ s hospital. Methods Comparing to the period of 2004-2006 with 2007-2009, we retrospectively reviewed eligible sputum isolates of common Gram negative bacilli and their drug resistance pattern. All specimens were processed according to standard microbiological methods for both quantitative and qualitative cultures. Pathogen was the single predominant growth after two consecutive cultures. Strict quality control was used in all test agents and paper disk for drug resistance analysis. Results Total of 598 Gram negative bacterial isolates were identified in patients over 6 years. The first 5 bacteria respectively were Escherichia coli 167 samples （ 27.93% ）, Klebsiella pneumoniae 109 samples （ 18.23% ）, Enterobacter cloacae 93 samples （ 15.55% ）, Acinetobacter baumannii 64 samples （ 10. 7% ）, Pseudomonas aeroginosa 43 samples （7. 19% ）. They were mostly sensitive to Imipenam, Amikacin, Piperacillin/Tazobactam. Most drug resistance rate was found in Amoxicillin,Ampicillin, Cephalosporin. Apart from Pseudomonas aeroginosa and Acinetobacter Baumannii, no Gram negative bacteria was found to be resistant to Imipenam. KlebsieUa pneumoniae and ESBL secreting Escherichia coli isolates were obviously increasing when compared to 3 years ago. Conelusion Comparing the period of 2004-2006, the Gram negative bacterial isolates were increasing in our PICU patients during 2007 to 2009. Close monitoring of drug resistance pattern changes in PICU would guide rational use of antibiotics in these critically ill children.