老年人下呼吸道嗜麦芽窄食单胞菌感染的临床分析

目的 探讨老年人下呼吸道嗜麦芽窄食单胞菌感染的危险因素及该菌对常用抗生素的敏感性。方法 分析40例老年下呼吸道嗜麦芽窄食单胞菌感染患者的临床资料，用K-B法测定该菌的体外药物敏感性。结果 全部患者均有基础疾病，其中慢性阻塞性肺疾病(COPD)20例(50．0％)，混合感染17例(42．5％)。均有抗生素应用史，70．0％的患者机体免疫功能低下，30．0％的患者曾有侵袭性治疗，平均住院时间达41．7d。临床症状及X线表现符合下呼吸道感染。药敏试验提示该菌呈现多重耐药，复方磺胺甲噁唑、环丙沙星、左氧氟沙星、阿米卡星、庆大霉素及氧氟沙星为较敏感抗生素。结论 老年下呼吸道嗜麦芽窄食单胞菌感染多发生于患有各种基础疾病、免疫功能低下及长期应用抗菌药物者，细菌耐药现象严重，诊断及治疗应根据病原学检查及药物敏感试验。

Analysis of the risk factors and drug sensitive tests of lower respiratory tract infection by stenotrophomonas maltophilia in the elderly

Objective To analyse risk factors of 40 cases with lower respiratory tract infection caused by stenotrophomonas maltophilia in the elderly and to investigate the drug sensitivities of Stenotrophomonas maltophilia strains. Methods Retrospective study of the clinical materials of 40 cases of lower respiratory tract infection caused by stenotrophomonas maltophilia in the elderly. The drug sensitivities against the stenotrophomonas maltophilia strains were determined by Kirby Bauer method. Results There were 30 males and 10 females. All of 40 cases had serious underlying diseases, most of which were COPD. Seventeen cases (42.5%) were mixed infections with other bacteria, most of which were P. aeruginosa, K. pneumoniae, acinetobacter calcoaceticus and candida albicans. Risk factors of infections were application of multiple antibiotics (100%), host immune suppression (70%), invasive treatment history (30%), and prolonged hospitalization. The average hospital staying time was 41.7 days. No specific clinical manifestations and chest X ray appearance were revealed. The antimicrobial tests in vitro showed that these strains were multiresistant to antibiotics, but TMP SMZ, ciprofloxacin, levofloxacin, amikacin, gentamicin and ofloxacin were sensitive. Conclusions Lower respiratory tract infection caused by Stenotrophomonas maltophilia in the elderly were commonly seen in patients who suffered from various underlying diseases, immunodeficiency, and longtime antibiotic overuse. Clinical isolates are highly resistant to most of antimicrobial agents. The diagnosis should be made according to bacteriologic examination. Antibiotics therapy is recommanded according to antimicrobial sensitivity test.