老年患者分离嗜麦芽寡养单胞菌的临床分布及耐药性监测

Distribution and antimicrobial resistance of Stenotrophomonas maltophilia isolated from senile patients

目的调查老年患者临床分离嗜麦芽寡养单胞菌的分布及对抗菌药物的敏感性,为临床合理使用抗菌药物提供依据。方法对医院2008年1月-2010年12月临床分离出嗜麦芽寡养单胞菌的老年患者进行病例回顾性分析,应用ATB Expression自动细菌鉴定系统对菌种进行鉴定,用K-B纸片扩散法对病原菌进行药物敏感性试验,按CLSI 2008年规定标准进行判断。结果从临床标本中共分离出嗜麦芽寡养单胞菌658株,其中标本90.1%来自呼吸道、2.6%来自体液、2.4%来自血液、2.1%来自尿液;老年患者均患有原发基础疾病,其中患≥2种基础疾病者占83.4%;老年患者嗜麦芽寡养单胞菌感染的危险因素为不合理使用抗菌药物、侵入性诊疗措施及住院时间长等;米诺环素和磺胺甲噁唑/甲氧苄啶对嗜麦芽寡养单胞菌的抗菌活性最强,耐药率分别为1.6%～4.7%和3.9%～12.5%。结论临床分离的嗜麦芽寡养单胞菌日益增多,由于嗜麦芽寡养单胞菌具有固有的广谱耐药特性,给临床治疗造成很大困难,因此,应重视嗜麦芽寡养单胞菌的监测和药敏试验,严格执行消毒隔离制度,临床医师应根据药敏试验结果,合理选用抗菌药物,减少老年患者嗜麦芽寡养单胞菌感染的发生率。

OBJECTIVE To investigate the distribution and antimicrobial resistance of Stenotrophomonas maltophil- ia isolates in senile patients so as to guide the rational use of antibiotics. METHODS The clinical isolates of the S. maltophilia isolated from the senile patients from Jan 2008 to Dec 2010 were retrospectively analyzed, The identifi- cation was analyzed by ATB Expression automatic microbiology analytical instrument system. The Kirby-Bauer agar diffusion method was applied for the antibiotic susceptibility testing and the results were read based on CLSI （2008） standards. RESULTS A total of 658 pathogen strains were isolated, among which 90.1% of the isolates were from sputum specimens, 2.6% from body fluid, 2.4% from blood, and 2.1% from urine. All the elderly patients suffered from underlying disease, 83.4% of the patients sufferred from two or more than two kinds of underlying diseases. The risk factors leading to the S. maltophilia infections were the unreasonable use of antibiot- ics ,invasive operation, and long hospitalization duration. The result of drug susceptibility testing indicated that the minocycline and trimethoprim/sulfamethoxazole showed great antibacterial activity against the S. maltophilia strains, with the drug resistance rates respectively varying from 1. 6% to 4. 70% and from 3. 9% to 12. 5%. CONCLUSION The clinical isolates of the S. maltophilia are increasing. As the S. maltophilia possesses the intrinsic broad-spectrum resistance, the clinical treatment is very difficult. We should pay much attention to the detection of S. maltophilia strains and their antimicrobial susceptibility. Furthermore, stringently executing institution of disinfection and isolation is also important. It is necessary for the clinicians to reasonably use antibiotics based on the result of drug sensitivity testing so as to reduce the incidence of S. maltophilia infections in the senile patients.