Liaqat Iram, Sumbal Fareeha, Sabri Anjum Nasim
Department of Microbiology and Molecular Genetics, University of the Punjab, Lahore, 54590, Pakistan.
Curr Microbiol. 2009 Aug;59(2):212-20. doi: 10.1007/s00284-009-9424-9. Epub 2009 May 30.
Despite the constantly increasing need for new antimicrobial agents, antibiotic drug discovery and development seem to have greatly decelerated in recent years. Presented with the significant problem of advancing antimicrobial resistance, the global scientific community has attempted to find alternative solutions; one of the most promising ones is the evaluation and use of old antibiotic compounds. A number of old antibiotic compounds, such as aminoglycosides, chloramphenicol, and tetracycline, are re-emerging as valuable alternatives for the treatment of difficult-to-treat infections. This study examined the in vitro potency for biofilm formation of five isolates (Klebsiella sp., Pseudomonas aeruginosa, Achromobacter sp., Klebsiella pneumoniae, and Bacillus pumilis) and the effects of antibiotics on these biofilms. Furthermore the quantitative analysis of planktonic, loosely attached cells, and their susceptibility to antibiotics was also determined. Twitching motility was observed to determine any effect in the biofilm forming capability of the isolates. All the isolates tested were efficient biofilm-forming strains in the polypropylene and borosilicate test tubes. Standard bacterial enumeration technique and CV staining produced equivalent results both in biofilm and planktonic assays. The biofilm formation of all the strains was affected in the presence of tetracycline or chloramphenicol. Highly significant decrease (P < 0.01) in biofilm formation was observed by treatment with chloramphenicol compared to tetracycline. In addition, the two antibiotics also affected adversely the planktonic and loosely attached cells of all isolates. Thus, testing the effects of older antibiotics on biofilms may supply useful information in addition to standard in vitro testing, particularly in diseases where biofilm formation is involved in the pathogenesis.
尽管对抗菌新药的需求持续增长，但近年来抗生素的研发似乎已大幅减速。面对日益严重的抗菌药物耐药性问题，全球科学界试图寻找替代解决方案；其中最有前景的方法之一是评估和使用旧的抗生素化合物。一些旧的抗生素化合物，如氨基糖苷类、氯霉素和四环素，正重新成为治疗难治性感染的有价值替代品。本研究检测了五种分离株（克雷伯菌属、铜绿假单胞菌、无色杆菌属、肺炎克雷伯菌和短小芽孢杆菌）形成生物膜的体外能力以及抗生素对这些生物膜的影响。此外，还对浮游菌、松散附着的细胞进行了定量分析，并测定了它们对抗生素的敏感性。通过观察颤动运动来确定其对分离株生物膜形成能力的影响。所有测试的分离株在聚丙烯和硼硅酸盐试管中都是高效的生物膜形成菌株。在生物膜和浮游菌检测中，标准细菌计数技术和结晶紫染色产生了相同的结果。在四环素或氯霉素存在的情况下，所有菌株的生物膜形成均受到影响。与四环素相比，用氯霉素处理后生物膜形成显著减少（P < 0.01）。此外，这两种抗生素也对所有分离株的浮游菌和松散附着的细胞产生了不利影响。因此，检测旧抗生素对生物膜的影响可能会为标准体外检测提供有用信息，特别是在生物膜形成参与发病机制的疾病中。
