Abdi-Ali Ahya, Hendiani Saghar, Mohammadi Parisa, Gharavi Sara
Department of Biology, Faculty of Science, Alzahra University, Tehran, IR Iran.
Jundishapur J Microbiol. 2014 Jan;7(1):e8606. doi: 10.5812/jjm.8606. Epub 2014 Jan 1.
Biofilms are communities of bacteria attached to the surfaces in an extracellular polymeric matrix which are associated with many chronic infections in humans. Acinetobacter spp. are emerging as a major cause of nosocomial infections and Acinetobacter baumannii is the predominant species associated with this kind of infections.
In the present study, the potential of biofilm formation of clinical isolates, A. baumannii, was assessed by using crystal violet method. Furthermore, susceptibility pattern of these strains to ciprofloxacin and imipenem was determined.
Biofilm formation by 75 A. baumannii isolates was evaluated by using microtiter plate and tube methods and crystal violet staining. Tube method was carried out under static and shaking conditions. Then, the susceptibility of isolates to ciprofloxacin and imipenem was determined.
Results showed that in tube method under shaking, 22% of clinical isolates were strong biofilm producers while 23% of them were not able to form biofilms. In this experiment, 18% and 42% of isolates were considered as moderate and weak biofilm-forming strains, respectively. In microtiter plate tests, 18% of strains were strong-biofilm producers and 25% of them were notable biofilm producers. In this assessment, 10% and 47% were considered as moderate and weak biofilm-forming isolates, respectively. The susceptibility tests, using microdilution method, confirmed that 92% of these isolates were resistant and 6.6% were susceptible to ciprofloxacin, although these results for imipenem were 68% and 24%, respectively.
It can be concluded that most of A. baumannii isolates can form biofilm in microtiter plate and tube. The results also verified that most of these isolates were resistant to ciprofloxacin and imipenem.
生物膜是附着在细胞外聚合基质表面的细菌群落，与人类许多慢性感染有关。不动杆菌属正成为医院感染的主要原因，鲍曼不动杆菌是与此类感染相关的主要菌种。
在本研究中，采用结晶紫法评估临床分离株鲍曼不动杆菌形成生物膜的潜力。此外，还测定了这些菌株对环丙沙星和亚胺培南的敏感性模式。
采用微量滴定板法、试管法和结晶紫染色法评估75株鲍曼不动杆菌分离株的生物膜形成情况。试管法在静态和振荡条件下进行。然后，测定分离株对环丙沙星和亚胺培南的敏感性。
结果显示，在振荡条件下的试管法中，22%的临床分离株是强生物膜形成菌，而23%的分离株不能形成生物膜。在该实验中，分别有18%和42%的分离株被认为是中度和弱生物膜形成菌株。在微量滴定板试验中，18%的菌株是强生物膜形成菌，25%的菌株是显著生物膜形成菌。在该评估中，分别有10%和47%被认为是中度和弱生物膜形成分离株。采用微量稀释法进行的药敏试验证实，这些分离株中有92%对环丙沙星耐药，6.6%敏感，尽管亚胺培南的这些结果分别为68%和24%。
可以得出结论，大多数鲍曼不动杆菌分离株在微量滴定板和试管中均可形成生物膜。结果还证实，这些分离株大多对环丙沙星和亚胺培南耐药。
