嗜麦芽窄食单胞菌院内感染的危险因素及耐药性分析

目的　调查嗜麦芽窄食单胞菌院内感染的危险因素和细菌的耐药谱 ,了解产金属 β内酰胺酶 (MBL)菌株与非产MBL菌株的药物敏感差异。　 方法　回顾性总结笔者单位 1998～ 2 0 0 2年嗜麦芽窄食单胞菌院内感染的情况 ,采用琼脂二倍稀释法测定 18种抗菌药物对 36株临床分离的院内感染嗜麦芽窄食单胞菌的体外抗菌活性 ,以MBL E试验法筛选MBL菌株。　结果　笔者单位嗜麦芽窄食单胞菌院内感染以下呼吸道感染为主 (88.9% ) ,88.2 %的患者有较严重的基础疾病 ,且 5 0 .0 %的患者曾接受亚胺培南 西司他丁钠盐治疗。新型氟喹诺酮类药物司帕沙星、左氧氟沙星、加替沙星和多西环素对 36株嗜麦芽窄食单胞菌的抑菌率分别为 97.2 %、94 .4 %、91.7%、83.3% ,甲氧苄氨嘧啶 磺胺甲基异恶唑和替卡西林 克拉维酸抑菌率分别为 6 3 9%和 5 8.3% ,亚胺培南 西司他丁钠盐、头孢他啶、头孢哌酮和氨曲南的耐药率在 80 %以上 ;36株菌中 16株产MBL菌对亚胺培南 西司他丁钠盐完全耐药 ,对氨曲南的敏感性高于非产MBL株。　结论　笔者单位嗜麦芽窄食单胞菌院内感染与严重基础疾病和应用亚胺培南 西司他丁钠盐有关 ,新型氟喹诺酮类药物对嗜麦芽窄食单胞菌院内感染株有较强的体外抗菌活性。

Investigation on the antibiotic resistance and risky factors of nosocomial infections caused by Stenotrophomonas maltophilia

OBJECTIVE: To investigate the antibiotic resistance and risky factors of nosocomial infections caused by Stenotrophomonas maltophilia, so as to help elucidate the difference of drug resistance between metallic beta-lactamase (MBL) producing and non-MBL producing strains. METHODS: Standard agar dilution method of NCCLS was employed in the isolation of 36 strains of Stenotrophomonas maltophilia from patients with nosocomial infection with respect to their in vitro antibiotic resistance to 18 kinds of antibiotics. MBL strains were identified by MBL-E test method. RESULTS: Stenotrophomonas maltophilia in our hospital was mainly identified in the lower respiratory tract (88.9%), in which 88.2% (30/34) of the patients had serious original diseases, 50% of whom had received Imipenem/cilastatin sodium treatment. Thirty-six strains of Stenotrophomonas maltophilia were susceptible to new types of fluoquinolone antibiotics, i.e. Sparfloxacin, levofloxacin, gatifloxacin and doxycycline, with inhibitory rate ranging 97.2%, 94.4%, 91.7% to 83.3%, respectively. They could also be inhibited by SMZ/TMP and Ticarcillin/Lavulanic acid with inhibitory rate of 63.9% and 58.3%, respectively. There were 16 strains out of 36 of MBL bacteria with complete resistance to Imipenem/cilastatin sodium, but with higher susceptibility to aztreonam than those non-MBL producing strains. CONCLUSION: The nosocomial infection in our hospital caused by Stenotrophomonas maltophilia seemed to be related with severe primary disease and the use of Imipenem/cilastatin sodium. The newly developed fluoroquinolones possessed powerful antibacterial potency on Stenotrophomonas maltophilia found in nosocomial infection.