Involvement of the Histone-Like Nucleoid Structuring Protein (H-NS) in Acinetobacter baumannii’s Natural Transformation

Pathogens

Susana Arriaga¹  Brent Nishimura¹  Jenny Escalante¹  Camila Pimentel¹  María Soledad Ramírez¹  Marcelo E. Tolmasky¹  Casin Le¹  Deja Rodgers¹  Rodrigo Sieira²  Tomás Subils³  Robert A. Bonomo⁴  Marisel R. Tuttobene⁵ 

[1] Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA 92831-3599, USA;Fundación Instituto Leloir—IIBBA CONICET, Buenos Aires C1405BWE, Argentina;Instituto de Procesos Biotecnológicos y Químicos de Rosario (IPROBYQ, CONICET-UNR), Rosario S2002LRK, Argentina;Research Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH 44106, USA;Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario S2002LRK, Argentina;

关键词: Acinetobacter baumannii;    H-NS;    natural transformation;    naturally competent;    DNA acquisition;   

DOI  :  10.3390/pathogens10091083

来源: DOAJ

【 摘 要 】

Most Acinetobacter baumannii strains are naturally competent. Although some information is available about factors that enhance or reduce the frequency of the transformation of this bacterium, the regulatory elements and mechanisms are barely understood. In this article, we describe studies on the role of the histone-like nucleoid structuring protein, H-NS, in the regulation of the expression of genes related to natural competency and the ability to uptake foreign DNA. The expression levels of the natural transformation-related genes pilA, pilT, pilQ, comEA, comEC, comF, and drpA significantly increased in a Δhns derivative of A. baumannii A118. The complementation of the mutant with a recombinant plasmid harboring hns restored the expression levels of six of these genes (pilT remained expressed at high levels) to those of the wild-type strain. The transformation frequency of the A. baumannii A118 Δhns strain was significantly higher than that of the wild-type. Similar, albeit not identical, there were consequences when hns was deleted from the hypervirulent A. baumannii AB5075 strain. In the AB5075 complemented strain, the reduction in gene expression in a few cases was not so pronounced that it reached wild-type levels, and the expression of comEA was enhanced further. In conclusion, the expression of all seven transformation-related genes was enhanced after deleting hns in A. baumannii A118 and AB5075, and these modifications were accompanied by an increase in the cells’ transformability. The results highlight a role of H-NS in A. baumannii’s natural competence.

【 授权许可】

Unknown