Molecular Mechanisms of Ethanol-Induced Pathogenesis Revealed by RNA-Sequencing

PLoS Pathogens

Michael Snyder¹  Laura Camarena²  Ghia Euskirchen²  Sebastian Poggio²  Vincent Bruno³ 

[1] Department of Genetics, Stanford Univeristy School of Medicine, Stanford, California, United States of America;Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America;Universidad Nacional Autónoma de México, Inst. Inv. Biomédicas, México, D.F., México

关键词: Ethanol;    Phospholipases;    Acinetobacter baumannii;    Gene expression;    Phosphates;    Outer membrane proteins;    Genomic libraries;    Virulence factors;   

DOI  :  10.1371/journal.ppat.1000834

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Acinetobacter baumannii is a common pathogen whose recent resistance to drugs has emerged as a major health problem. Ethanol has been found to increase the virulence of A. baumannii in Dictyostelium discoideum and Caenorhabditis elegans models of infection. To better understand the causes of this effect, we examined the transcriptional profile of A. baumannii grown in the presence or absence of ethanol using RNA-Seq. Using the Illumina/Solexa platform, a total of 43,453,960 reads (35 nt) were obtained, of which 3,596,474 mapped uniquely to the genome. Our analysis revealed that ethanol induces the expression of 49 genes that belong to different functional categories. A strong induction was observed for genes encoding metabolic enzymes, indicating that ethanol is efficiently assimilated. In addition, we detected the induction of genes encoding stress proteins, including upsA, hsp90, groEL and lon as well as permeases, efflux pumps and a secreted phospholipase C. In stationary phase, ethanol strongly induced several genes involved with iron assimilation and a high-affinity phosphate transport system, indicating that A. baumannii makes a better use of the iron and phosphate resources in the medium when ethanol is used as a carbon source. To evaluate the role of phospholipase C (Plc1) in virulence, we generated and analyzed a deletion mutant for plc1. This strain exhibits a modest, but reproducible, reduction in the cytotoxic effect caused by A. baumannii on epithelial cells, suggesting that phospholipase C is important for virulence. Overall, our results indicate the power of applying RNA-Seq to identify key modulators of bacterial pathogenesis. We suggest that the effect of ethanol on the virulence of A. baumannii is multifactorial and includes a general stress response and other specific components such as phospholipase C.

【 授权许可】

CC BY