Erratum for Richmond et al., The Acinetobacter baumannii Two-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner

Abstract

V olume 7, no. 2, doi:10.1128olume 7, no. 2, doi:10. /mBio.00430-16, 2016. After careful review, it has come to our attention that the text in the abstract of our paper is at variance with one sentence in the article. During writing, revision, and editing, the sense was changed. The revised abstract below shows the correct text. We thank Maria Ramirez for bringing this to our attention.The opportunistic pathogen Acinetobacter baumannii is able to persist in the environment and is often multidrug resistant (MDR), causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in an ex vivo porcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion of adeB impacted on the ability to form a biofilm on plastic for strain AYE only and on the virulence in Galleria mellonella for Singapore strain 1 only. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example, A. baumannii lacking AdeRS displayed decreased expression of adeABC and a pgaC-like gene and increased expression of pil and com genes, whereas loss of AdeB resulted in decreased expression of pil, com, and ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and anti-biofilm discovery. Published 21 June 2016Citation Richmond GE, Evans LP, Anderson MJ, Wand ME, Bonney LC, Ivens A, Chua KL, Webber MA, Sutton JM, Peterson ML, Piddock LJV. 2016. Erratum for Richmond et al., The Acinetobacter baumannii two-component system AdeRS regulates genes required for multidrug efflux, biofilm formation, and virulence in a strain-specific manner. mBio 7(3): e00852-16.

Microbial Disruption Indices to Detect Colonization With Multidrug-Resistant Organisms

“…25–27 These results are consistent with our phenotypic identification of MDROs using classical culture-dependent microbiological methods, and they highlight the potential to identify metabolic pathways and their byproducts as potential biomarkers of MDRO colonization, which may be widely applicable considering the functional stability of the human microbiome. 28 A recent study by Zhernakova et al 29 showed that the protein chromogranin A, retrieved from the stool, had a strong negative correlation with microbial diversity in the gut, suggesting that this fecal biomarker could be used to ascertain gut health.…”

Multidrug efflux pumps: structure, function and regulation

“…The response regulator component AdeR activates adeABC expression by binding to a direct-repeat motif in the intercistronic region 114 , and mutations in AdeR lead to enhanced efflux activity of AdeB 115 . AdeRS not only regulates the expression of the tripartite pump system encoded by adeABC, but also genes for biofilm formation and virulence 116 . Interestingly, TCSs can regulate more than one type of pump, such is the case of BaeSR in A. baumannii, which is proposed to indirectly regulate AdeAB and AdeIJK RND efflux pumps and also the MacAB ABC pump, and which has been suggested to influence increase resistance to tigecycline.…”

Mechanistic insight into how multidrug resistant Acinetobacter baumannii response regulator AdeR recognizes an intercistronic region

“…Within AdeRS, the histidine kinase AdeS senses environmental stimuli, while the response regulator AdeR mediates the cellular response by receiving a phosphoryl signal from AdeS and further stimulates the expression of its target genes ( 15 , 17 , 18 ). It is not only the production of the AdeABC efflux pump that is mediated; it is proposed that AdeRS also regulates genes required for biofilm formation and virulence, but in a strain-specific manner ( 19 ). Therefore, two-component systems have been highlighted to potentially serve as an effective drug target, especially by targeting the response regulator ( 16 , 20 ).…”