Löfmark Sonja, Jernberg Cecilia, Jansson Janet K, Edlund Charlotta
Department of Laboratory Medicine, Karolinska Institute, SE-141 86 Stockholm, Sweden.
J Antimicrob Chemother. 2006 Dec;58(6):1160-7. doi: 10.1093/jac/dkl420. Epub 2006 Oct 17.
The aim was to study the long-term consequences of 1 week clindamycin administration regarding selection and persistence of resistance, resistance determinants and diversity of the Bacteroides spp. in the intestinal microflora.
A total of 1306 Bacteroides isolates were collected from constitutively cultured faecal samples during a 2 year period from eight healthy volunteers. The strains were identified by biochemical and genotyping methods. MIC values were determined by the agar dilution method and presence of resistance genes was screened by real-time PCR.
Ecological changes in the intestinal microflora persisting up to 24 months were recorded after a 7 day clindamycin administration to four healthy volunteers. Compared to a control group, not exposed to clindamycin, an enrichment and stabilization of resistant Bacteroides strains and resistance determinants were discovered up to 2 years after clindamycin exposure.
The results indicate that even a short-term antibiotic administration can cause long-term alterations in the commensal microbiota of individual subjects, detectable 2 years after dosing. The recorded selection and persistence of resistant strains and resistance genes, illustrates the importance of increasing our knowledge of the role of the abundant intestinal microbial community as a reservoir for spread of resistance.
本研究旨在探讨克林霉素连续给药1周对肠道微生物群中拟杆菌属细菌的耐药性选择与持续存在、耐药决定因素及多样性的长期影响。
在两年时间里，从8名健康志愿者经连续培养的粪便样本中总共收集了1306株拟杆菌分离株。采用生化和基因分型方法对菌株进行鉴定。通过琼脂稀释法测定最低抑菌浓度（MIC）值，并通过实时聚合酶链反应筛选耐药基因的存在情况。
对4名健康志愿者给予7天克林霉素治疗后，记录到持续长达24个月的肠道微生物群生态变化。与未接触克林霉素的对照组相比，在接触克林霉素后长达2年的时间里，发现耐药拟杆菌菌株和耐药决定因素出现富集和稳定现象。
结果表明，即使短期使用抗生素也可导致个体受试者共生微生物群的长期改变，在给药后2年仍可检测到。所记录的耐药菌株和耐药基因的选择与持续存在，说明了加强我们对丰富的肠道微生物群落作为耐药性传播库的作用认识具有重要意义。
