Characterization of biofilm formation by clinical isolates of Mycobacterium avium
Characterization of biofilm formation by clinical isolates of Mycobacterium avium
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DOI：
10.1099/jmm.0.05224-0
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发表时间：
2003-09-01
影响因子：
3
通讯作者：
Bermudez, LE
中科院分区：
文献类型：
--
作者：
Carter, G;Wu, M;Bermudez, LE
禽分枝杆菌是一种环境微生物，存在于天然水源和城市水源以及土壤中。最近在桑拿墙壁和城市自来水管道中发现了禽类分支杆菌生物膜，并可能在环境和宿主中的毒力菌株的生存中发挥作用。采用体外模型，在聚氯乙烯表面形成生物膜，结晶紫染色检测生物膜，光学显微镜观察生物膜，A(570)定量。用从艾滋病患者血液中分离的MAC101、MAC100、MAC104、MAC109、MACA5和MAC5501株进行检测。生物膜的形成依赖于水中Ca~(2+)、Mg~(2+)或Zn~(2+)离子的存在，当浓度为1微米时，生物膜的形成效果最好。在碳源中加入2%的葡萄糖和蛋白胨可促进生物膜的形成，而腐植酸可部分抑制生物膜的形成。由于滑动运动与糖肽脂(GPL)的量有关，因此使用TLC来确定GPL的存在。形成生物被膜的培养上清液诱导形成稳定的生物被膜，而阿米卡星在亚抑制浓度下阻止了禽类分支杆菌生物被膜的形成。与浮游细菌相比，生物膜中的细菌对氯以及接触过硫酸钾和醋酸氯己亚胺的抵抗力更强。鉴定参与生物被膜形成的基因，进一步研究抗菌剂对生物被膜形成的影响，可以确定抑制禽类支原体生物被膜形成和定植的方法。
Mycobacterium avium is an environmental organism encountered in natural and urban water sources as well as soil. M. avium biofilm has recently been identified on sauna walls and in city water pipes and might have a role in the survival of virulent strains in the environment and in the host. To characterize the M. avium biofilm, an in vitro model was adapted wherein biofilm develops on a PVC surface, Biofilm was detected by staining with crystal violet and visualization by optical microscopy and quantified by A(570). M. avium strains MAC 101, MAC 100, MAC 104, MAC 109, MAC A5 and MAC 5501 (all isolated from the blood of AIDS patients) were used in the assays. Biofilm formation was dependent on the presence of Ca2+, Mg2+ or Zn2+ ions in the water, with the maximal effect seen at a concentration of 1 muM. The presence of 2% glucose and peptone as sources of carbon increased the formation of biofilm, while this was partially inhibited by humic acid. Since sliding motility has been associated with the amount of glycopeptidolipid (GPL), TLC was used to determine the presence of GPL. The supernatant of a biofilm-forming culture induced formation of a stable biofilm and amikacin blocked the establishment of biofilm by M. avium strains at subinhibitory concentrations. Bacteria in the biofilm were more resistant to chlorine as well as to exposure to potassium monopersulfate and chloroheximide acetate than were planktonic bacteria. Identification of M. avium genes involved in biofilm formation and further studies of the effect of antimicrobials on the establishment of biofilm may identify approaches for inhibiting M. avium biofilm formation and colonization.