近12年下呼吸道感染病原菌变迁及耐药性分析

Change of bacterial pathogens and resistance rates in lower respiratory tract infection during recent 12 years

目的:了解1996-2007年湘雅医院呼吸科下呼吸道感染住院患者病原菌变迁及耐药性情况。方法:对呼吸病房下呼吸道感染住院患者痰菌(或支纤镜吸取分泌物)培养阳性标本结果进行回顾性统计分析。结果:分离出细菌2966株,其中革兰阴性杆菌占86.9%,病原菌主要为铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌、副流感嗜血杆菌、大肠埃希菌和流感嗜血杆菌;革兰阳性球菌占13.1%,主要病原菌为金葡菌和肺炎链球菌。近四年革兰阴性杆菌有所增加,而革兰阳性球菌有所减少。革兰阴性杆菌中,副流感嗜血杆菌和流感嗜血杆菌的比例明显升高;革兰阳性球菌中,金黄色葡萄球菌比例降低、肺炎链球菌比例升高。药敏试验结果提示主要革兰阴性杆菌对美洛培南、头孢哌酮/舒巴坦、阿米卡星均较敏感。铜绿假单胞菌还对头孢他啶、哌拉西林/他唑巴坦、氨曲南敏感性高,对头孢曲松、氨苄西林/舒巴坦、头孢噻肟耐药率增高。鲍曼不动杆菌对氨苄西林/舒巴坦敏感性较好,但耐药率有增高趋势,对头孢噻肟、头孢他啶、环丙沙星耐药率明显增高。肺炎克雷伯菌和大肠埃希菌对头孢哌酮、头孢曲松、头孢噻肟、头孢他啶、氨苄西林/舒巴坦耐药率增高;但二者对头孢他啶仍然保持相对敏感,耐药率为25.3%和27.6%。嗜血杆菌属中,流感嗜血杆菌与副流感嗜血杆菌的敏感抗生素谱相似,均对强力霉素、壮观霉素、头孢类抗生素耐药性低,而对喹诺酮类和青霉素敏感性差。主要革兰阳性球菌对阿奇霉素、克林霉素、红霉素及青霉素耐药率均较高;二者对红霉素耐药率明显增高。其中金葡菌对万古霉素均敏感,对左氟沙星、苯唑青霉素、头孢唑啉、美洛培南、强力霉素耐药率均明显增高。肺炎链球菌还对美洛培南、左氟沙星耐药率低,耐药率无明显增高。结论:近年下呼吸道感染病原菌以革兰阴性杆菌为主;主要病原菌对大部分抗菌药物的耐药率有逐渐增高的趋势,临床应合理应用抗菌药,以延缓细菌耐药性的产生。

Objective： To investigate the change of distribution and antibiotic resistance rates of pathogenic bacteria isolated from inpatients with lower respiratory tract infection in Department of Respiratory Medicine during 1996-2007. Methods： All the clinical isolates were analyzed retrospectively from sputum or secretion of lower respiratory tract from 1996 to 2007. Antibiotic susceptibility was tested by Kirby-Bauer method. Results： A total of 2966 clinical isolates were collected, including 2578 （86.9%） strains ofgram-negativebacilli and 388 （13.1%）strains ofgram-positive cocci. The most important gram-negative pathogens were Pseudomonas aeruginosa, Kleb-siella pneumoniae, Acinetobacter baumani, Haemophilus parainfluenzae,Escherichia coli and Hemophilies influenzae. The most common gram-positive cocci were Staphylococcus aureus and Streptococcus pneumonia. The proportionofthe gram-positive microorganisms decreased relatively since the year of 2004, while that of the gram-negative microorganism increased gradually. The proportion of Haemophilus parainfluenzae and Hemophilies influenzae increased significantly since 2004, while that of Staphylococcus aureus decreased significantly. Most strains of gram-negative bacilli were susceptible to meropenem. Cefoperazone / sulbactam and amikacin. P. aeruginosa isolates were relatively susceptible to ceftazidime,piperacillin/tazobactam, aztreonam, but highly resistant to ceftriaxone, ampicillin/sulbactam and cefotaxim. The resistance of A.baumani to ampicillin/sulbactam, cefotaxim, ceftazidime and ciprofloxacin has significantly increased. The resistance of K.pneumoniae and E.coli to cefoperazone, ceflriaxone, cefotaxime, ceftazidime and ampicillin /sulbactam has also increased. But they were relatively susceptible to ceftazidime, and the rates of antibiotic resistance were 25.3 % and 27.6 %. Haemophilus parainfluenzae and Hemophilies influenzae were susceptible to deoxycycline, actinospectacin, β-lactams, while resisted to penicilin and trimethoprim-sulfamethoxazole. The major gram-positive isolates were highly resistant to azithromycin, erythromycin, penicilin and clindamycin. The resistance of them to erythromycin has significantly increased. All S. aureus isolates were susceptible to vancomycin. The resistance to levofloxacin, oxacillin, meropenem, todeoxycycline and cefazolin has significantly increased.S. pneumoniae isolates were highly susceptible to meropenem and levofloxacin. The resistance has not significantly increased. Conclusions： Gram-negative bacilli are still the leading pathogens in lower respiratory tract infection during the past years in our department. Antibiotic resistance becomes more prevalent in some major pathogens.Rationaluse ofantibioticsis important forthe containment ofoacterial resistance.