嗜麦芽窄食单胞菌体外药敏试验及耐药性分析

Antibiotic Susceptibility Test and Resistant Characteristics of Stenotrophomonas Maltophilia

目的检测不同孵育时间对嗜麦芽窄食单胞菌药敏试验结果的影响,观察嗜麦芽窄食单胞菌对8种氟喹诺酮类抗生素的交叉耐药性及其他各种抗生素耐药现状,以指导临床合理用药。方法采用纸片扩散法测定临床标本中分离的72株嗜麦芽窄食单胞菌孵育24h和48h对各种抗生素的体外抗菌活性。结果无论培养24h还是48h,嗜麦芽窄食单胞菌敏感率最高的依次是莫西沙星、加替沙星、左氧氟沙星、复方新诺明、头孢哌酮/舒巴坦、氧氟沙星、米诺环素,敏感率均大于60%;对大多数β-内酰胺类和氨基糖苷类抗生素高度耐药,对亚胺培南100%耐药。药敏试验延长至48h判读结果时,部分在24h敏感的菌株抑菌区内可见小的耐药菌生长。结论嗜麦芽窄食单胞菌对各种抗菌药物均有不同程度耐药性,治疗首选新一代氟喹诺酮类抗生素和复方新诺明,延长药敏培养时间可检出更多生长缓慢的耐药菌株。

Objective To investigate the results of antibiotic susceptibility test of Stenotrophomonas maltophilia at different time points and the multiple resistance of Stenotrophomonas maltophilia isolated in our hospital to fluoroquinolones and non-quinolones in order to help clinicians choose antimicrobial agents.Methods Totally 72 strains of Stenotrophomonas maltophilia were isolated from various clinical specimens,and the disc diffusion method was used to detect the antimicrobial susceptibility of various antibacterials against Stenotrophomonas maltophilia at 24h and 48h.Results The antimicrobial susceptibility rates of antibacterials to Stenotrophomonas maltophilia strains at 24h or 48h in order from the highest were as follows ： moxifloxacin,gatifloxacin,levofloxacin,SMZ/TMP,cefoperazone/ sulbactam,of loxacin and minomycin,with their rates as more than 60%,and 72 strains showed more higher resistance to antibiotics including most of β-actams and aminoglycosides,and the resistance rate of imipenem was 100 %.In extending time of antimicrobial susceptibility test from 24h to 48h,there were a few small resistance strains in the inhibition zone which showed susceptibility at 24h.Conclusion The multiple resistance of Stenotrophomonas maltophilia is investigated.The new fluoroquinolones and SMZ/ TMP show the highest antibacterial activity against Stenotrophomonas maltophilia.Extending time of antimicrobial susceptibility test can find much more resistance strains growing slowly.