中国城市成人社区获得性肺炎665例病原学多中心调查

目的 研究引起社区获得性肺炎（CAP）的病原体分布及患者入选前是否应用抗生素、肺炎患者预后研究组（PORT）分级等的情况，同时检测常见病原菌的耐药性。方法 入选2003年12月至2004年11月中国7个城市12个中心的665例CAP患者并进行病原体检测。病原体确定诊断的阳性判断标准为：（1）合格痰标本培养出1株或多株细菌；（2）血培养检出病原体；（3）间隔2～4周采集的2次标本的血清肺炎支原体、肺炎衣原体或嗜肺军团菌抗体滴度呈现4倍或4倍以上增高或降低。应用琼脂稀释法对常见病原菌进行最低抑菌浓度（MIC）检测。结果 在610例同时进行了细菌培养和血清学检测的患者中，肺炎支原体是最常见的病原体，阳性率为20．7％（126例），其后依次为肺炎链球菌10．3％（63例）、流感嗜血杆菌9．2％（56例）、肺炎衣原体6，6％（40例）、肺炎克雷伯杆菌6.1％（37例）、嗜肺军团菌5.1％（31例）、金黄色葡萄球菌3．8％（23例）、大肠杆菌1．6％（10例）、卡他莫拉菌1.3％（8例）、铜绿假单胞菌1．0％（6例）。在195例细菌培养阳性患者中，共有10．2％（62例）合并非典型病原体感染。69株肺炎链球菌，对青霉素、阿奇霉素和莫西沙星的不敏感率分别为20．3％、75．4％和4．3％。结论 非典型病原体尤其是肺炎支原体感染在CAP中占据重要地位；细菌合并非典型病原体的混合感染占10．2％。肺炎链球菌、流感嗜血杆菌仍为常见的致病细菌，我国致CAP肺炎链球菌对大环内酯类抗生素的耐药率高达75．0％以上，对青霉素的不敏感率为20，3％．

A multicentre study on the pathogenic agents in 665 adult patients with community-acquired pneumonia in cities of China

OBJECTIVE: To investigate the pathogenic causes of community-acquired pneumonia (CAP) in adult patients in China, the relation of previous antibiotic use and the Pneumonia Patient Outcome Research Team (PORT) classification to microbial etiology, and the prevalence of drug resistance of common CAP bacteria. METHODS: A prospective study was performed on 665 consecutive adult patients with CAP at 12 centers in 7 Chinese cities during one year. The etiology of pneumonia was considered if one of the following criteria was met: (1) valid sputum sample yielding one or more predominant strains; (2) blood cultures yielding a bacterial pathogen; (3) seroconversion, a > or = 4-fold increase or decrease titers of antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila. Minimum inhibitory concentration (MIC) of respiratory tract isolates was determined using the agar dilution method. RESULTS: Pathogens were identified in 324/610 patients (53.1%) with valid serum samples and sputum cultures as follows: Mycoplasma pneumoniae (126, 20.7%), Streptococcus pneumoniae (63, 10.3%), Haemophilus influenzae (56, 9.2%), Chlamydia pneumoniae (40, 6.6%), Klebsiella pneumoniae (37, 6.1%), Legionella pneumophila (31, 5.1%), Staphylococcus aureus (23, 3.8%), Escherichia coli (10, 1.6%), Moraxella catarrhalis (8, 1.3%), Pseudomonas aeruginosa (6, 1.0%). Of 195 patients with a bacterial pathogen, an atypical pathogen was identified in 62 (10.2%) cases. The non-susceptibility rate of Streptococcus pneumoniae to penicillin, azithromycin, and moxifloxacin was 20.3%, 75.4% and 4.3% respectively. CONCLUSIONS: Atypical pathogens have important role in CAP, with Mycoplasma pneumoniae being the most common pathogen, and mixed infection of atypical pathogens with bacteria was found in 10.2% of the cases. Streptococcus pneumoniae and Haemophilus influenzae remain the most important bacteria for CAP. More than 75.0% of Streptococcus pneumoniae was resistant to macrolides and 20.3% was resistant to penicillin.