苏南地区某二级医院近3年下呼吸道感染病原菌分布及耐药性监测

目的 调查我院近3年下呼吸道感染主要病原菌的分布与耐药情况,并以重症监护病房(ICU)与非ICU相比较,观察两者的不同之处,为临床合理选用抗菌药物提供依据.方法 使用VITEK2-compact微生物检测系统对我院下呼吸道感染住院患者的痰液标本中临床分离的941株病原菌进行细菌鉴定,采用MIC法进行药敏试验.结果 临床分离的941株细菌中,368株来自ICU,革兰阴性杆菌占85.02%(800/941).ICU与非ICU耐甲氧西林金黄色葡萄球菌(MRSA)的检出率分别为100.00%(25/25)和73.53%(25/34)(P＜0.01).病原菌中最常见的菌种依次为肺炎克雷伯菌21.15%(199/941)、铜绿假单胞菌20.30%(191/941)、鲍曼不动杆菌10.31%(97/941)、嗜麦芽窄食单胞菌7.97%(75/941)和大肠埃希菌7.44%(70/941),ICU与非ICU前5位病原菌相同,但构成比例不同.肺炎克雷伯菌和大肠埃希菌产生超广谱β-内酰胺酶(ESBL)的检出率分别为57.79%(115/199)和51.43%(36/70),ICU的ESBL检出率与非ICU比较差异具有统计学意义(P＜0.05).肺炎克雷伯菌、大肠埃希菌对亚胺培南敏感度最高,耐药率分别为5.06%和18.18%;铜绿假单胞菌对头孢哌酮/舒巴坦、哌拉西林/他唑巴坦、环丙沙星、头孢吡肟、亚胺培南、阿米卡星的耐药率在18.52%～27.66%之间;鲍曼不动杆菌耐药情况比较严重,只有对加替沙星和亚胺培南的耐药率低于30%;嗜麦芽窄食单胞菌耐药情况最严重,只对复方磺胺甲噁唑高度敏感,耐药率为9.09%,对头孢曲松、头孢噻肟、哌拉西林、阿莫西林/舒巴坦钠和亚胺培南几乎全部耐药.我院存在较高的复合感染率,为11.62%(84/723),主要发生在ICU,复合感染率及感染株数在2009年监测中明显下降.结论 革兰阴性杆菌为医院下呼吸道感染主要病原菌,且呈现多重耐药趋势.亚胺培南、头孢哌酮/舒巴坦和哌拉西林/他唑巴坦是治疗下呼吸道感染的有效药物.动态监测细菌的耐药性,合理选择抗生素,减少高危因素并制定有效的防治措施显得至关重要.

Distribution and drug resistance monitoring of pathogenic bacteria in lower respiratory tract infection in recent three years

Objective To investigate the distribution and drug resistance of pathogenic bacteria in lower respiratory tract infection in the hospital in recent three years and to provide a basis for the clinical reasonable use of antibacterials through comparing the bacteria obtained from intensive care unit (ICU)and non-ICU. Methods 941 strains of pathogenic bacteria clinically isolated from sputum specimen of hospital patients with lower respiratory tract infection were identified by VITEK2-compact microbial detection system. The bacterial susceptibility test was made by MIC method. Results Among the isolated 941 strains of bacteria,368 strains were from ICU,gram-negative bacilli accounted for 85.02% (800/941).The detection rates of methicilli-resistant Staphylococcus aureus from ICU and non-ICU were 100.00%(25/25) and 73.53% (25/34)( P ＜0.01). The most common pathogens were Klebsiella pneumoniae (21.15%, 199/941 ), Pseudomonas aeruginosa ( 20.30%, 191/941 ), Acinetobacter baumanni ( 10. 31%,97/941 ), Stenotrophomonas maltophilia ( 7.97 %, 75/941 ) and Escherichia coli ( 7.44 %, 70/941 ). The detection rates of extended spectrum β-lactamases (ESBL) in Klebsiella pneumoniae and Escherichia coli were 57.79% ( 115/199 ) and 51.43% (36/70), respectively. There was statistical difference on the detection rate of ESBI between ICU and non-ICU ( P ＜0.05). Klebsiella pneumoniae and Escherichia coli were the most sensitive to imipenem, the resistance rates of them were 5.06 % and 18.18 %, respectively.The drug resistance rates of Pseudomonas aeruginosa to cefoperazone/sulbactam,piperacillin/tazobactam,ciprofloxacin, cefepime, imipenem, amikacin were between 18. 52 % and 27.66 %. The drug resistance rate of Acinetobacter baumanni to gatifloxacin and imipenem were both less than 30%. Stenotrophomonas maltophilia was only highly sensitive to sulfamethoxazole, the resistance rate was 9. 09%, and it was almost drug-resistant to ceftriaxone, cefotaxime, piperacillin, amoxicillin/sulbactam and imipenem. The rate of complex infection was higher in our hospital (11.62 %, 84/723), especially in ICU. The rate of complex infection and the number of infection strains obviously declined in 2009. Conclusions Gram-negative bacilli are main pathogens in patients with lower respiratory tract infection in the hospital, and most of them are multidrug resistant. Imipenem, cefoperazone/sulbactam and piperacillin/tazobactam are effective antibiotics for treating lower respiratory tract infection. Dynamic monitoring of bacterial resistance,reasonable choice of antibiotics,reduction of risk factors and effective control measures are crucial.