Background

Biofilm development by bacteria is considered to be an essential stage in the bacterial infection. Acinetobacter nosocomialis is an important nosocomial pathogen causing a variety of human infections. However, characteristics and specific determinants of biofilm development have been poorly characterized in A. nosocomialis.

Objective

The aim of this study was to investigate the factors involved in the biofilm development by A. nosocomialis.

Methods

Library of random transposon mutants was constructed using the Tn5 mutagenesis. The mutant strains, in which the ability of biofilm formation was significantly impaired, were screened by gentian violet staining. The roles of BfmR and BfmS were determined by constructing a bfmR and bfmS deletion mutant and analyzing the effects of bfmR and bfmS mutation on the biofilm development and motility of A. nosocomialis.

Results

We identified a biofilm-defective mutant in which a transposon insertion inactivated an open reading frame encoding the BfmR in a two-component regulatory system consisting of BfmR and BfmS. The bfmR mutant revealed a significant reduction in biofilm formation and motility compared to wild-type strain. Deficiency in the biofilm formation and motility of the bfmR mutant was restored by single copy bfmR complementation. In contrast, the bfmS mutant had no effect on biofilm formation.

Conclusion

A. nosocomialis has a two-component regulatory system, BfmRS. BfmR is a response regulator required for the initial attachment and maturation of biofilm during the biofilm development as well as the bacterial growth. BfmR could be a potential drug target for A. nosocomialis infection.

中文翻译：

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医院不动杆菌 BfmRS 的鉴定和表征，这是生物膜形成所必需的双组分调节系统

背景

细菌形成生物膜被认为是细菌感染的重要阶段。院内不动杆菌是一种重要的院内病原体，可引起多种人类感染。然而，生物膜发育的特征和具体决定因素在A中的特征还很不清楚。医院。

客观的

本研究的目的是调查A生物膜形成所涉及的因素。医院。

方法

使用 Tn5 诱变构建随机转座子突变体文库。通过龙胆紫染色筛选生物膜形成能力显着受损的突变株。通过构建bfmR和bfmS缺失突变体，分析bfmR和bfmS突变对院内放线菌生物膜发育和运动的影响，确定BfmR和BfmS的作用。

结果

我们鉴定了一种生物膜缺陷突变体，其中转座子插入使编码 BfmR 的开放阅读框失活，该开放阅读框在由 BfmR 和 BfmS 组成的双组分调控系统中编码。与野生型菌株相比，bfmR突变体显示生物膜形成和运动显着减少。通过单拷贝bfmR互补，可以恢复bfmR突变体生物膜形成和运动方面的缺陷。相反，bfmS突变体对生物膜形成没有影响。

结论

A。nosocomialis有一个由两部分组成的监管系统：BfmRS。 BfmR 是生物膜发育以及细菌生长过程中生物膜初始附着和成熟所需的响应调节剂。 BfmR 可能是院内放线菌感染的潜在药物靶点。