Shafiei Morvarid, Abdi Ali Ahya, Shahcheraghi Fereshteh, Saboora Azra, Akbari Noghabi Kambiz
Department of Biology, Faculty of Science, Alzahra University, Tehran, IR Iran.
Department of Bacteriology, Pasteur Institute of Iran, Tehran, IR Iran.
Jundishapur J Microbiol. 2014 Feb;7(2):e14358. doi: 10.5812/jjm.14358. Epub 2014 Feb 1.
Biofilm formation is a major pathogenic factor in different bacteria such as Pseudomonas aeruginosa. A number of studies have reported that bacterial biofilms show different levels of antibiotic resistance. In order to re-sensitize the bacterial biofilms to antibiotics, biofilms should be dispersed.
In this study, the effect of n-butanolic Cyclamen coum extract in combination with ciprofloxacin was examined on one, three and five day old P. aeruginosa biofilms. The synergistic effect of n-butanolic C. coum extract and ciprofloxacin towards dispersing pre-established P. aeruginosa biofilms was also studied.
The ability of biofilm formation by six different P. aeruginosa strains was confirmed by microtiter plate method and PCR assay for the cupA gene. The extraction of C. coum tubers was achieved by fractionation method using different solvents. The minimum inhibitory concentration (MIC) of n-butanolic C. coum extract and ciprofloxacin against planktonic cells was evaluated using agar well diffusion and microdilution methods. The microdilution chequerboard method was used to determine the fractional biofilm eradication concentration index (FBCI), when the combination of n-butanolic C. coum extract and ciprofloxacin were used against P. aeruginosa biofilms.
The ability of biofilm formation by P. aeruginosa strains was quantitatively confirmed. The PCR method confirmed the existence of cup A gene (172 bp) in all studied strains. Saponin content of the n-butanolic C. coum extract was 156 µg/mL. The extract revealed antibacterial activity against planktonic cells of P. aeruginosa strains. The results showed that one and three day old biofilms are affected by either ciprofloxacin or n-butanolic C. coum extract. However, n-butanolic C. coum extract in combination with ciprofloxacin was significantly more effective against P. aeruginosa biofilms.
Using n-butanolic C. coum extract in combination with ciprofloxacin offers a novel strategy to control biofilm-based infections caused by P. aeruginosa.
生物膜形成是铜绿假单胞菌等不同细菌中的主要致病因素。许多研究报告称，细菌生物膜表现出不同程度的抗生素抗性。为了使细菌生物膜重新对抗生素敏感，应分散生物膜。
本研究考察了正丁醇提取的仙客来提取物与环丙沙星联合使用对1日龄、3日龄和5日龄铜绿假单胞菌生物膜的影响。还研究了正丁醇提取的仙客来提取物与环丙沙星对已形成的铜绿假单胞菌生物膜的协同分散作用。
采用微量滴定板法和cupA基因PCR检测法，确认6株不同铜绿假单胞菌菌株形成生物膜的能力。采用不同溶剂分级分离法提取仙客来块茎。采用琼脂孔扩散法和微量稀释法评估正丁醇提取的仙客来提取物和环丙沙星对浮游细胞的最低抑菌浓度（MIC）。当正丁醇提取的仙客来提取物与环丙沙星联合用于铜绿假单胞菌生物膜时，采用微量稀释棋盘法测定生物膜根除浓度分数指数（FBCI）。
定量确认了铜绿假单胞菌菌株形成生物膜的能力。PCR方法证实了所有研究菌株中均存在cupA基因（172 bp）。正丁醇提取的仙客来提取物中皂苷含量为156 µg/mL。该提取物对铜绿假单胞菌菌株的浮游细胞具有抗菌活性。结果表明，1日龄和3日龄生物膜受环丙沙星或正丁醇提取的仙客来提取物影响。然而，正丁醇提取的仙客来提取物与环丙沙星联合使用对铜绿假单胞菌生物膜的效果显著更佳。
正丁醇提取的仙客来提取物与环丙沙星联合使用为控制铜绿假单胞菌引起的基于生物膜的感染提供了一种新策略。
