https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 The Acinetobacter baumannii disinfectant resistance protein, AmvA, is a spermidine and spermine efflux pump https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39776 Wed 22 Jun 2022 12:26:08 AEST ]]> Characterizing the mechanism of action of an ancient antimicrobial, Manuka honey, against Pseudomonas aeruginosa using modern transcriptomics https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38597 Pseudomonas aeruginosa We show that no single component of honey can account for its total antimicrobial action, and that honey affects the expression of genes in the SOS response, oxidative damage, and quorum sensing. Manuka honey uniquely affects genes involved in the explosive cell lysis process and in maintaining the electron transport chain, causing protons to leak across membranes and collapsing the proton motive force, and it induces membrane depolarization and permeabilization in P. aeruginosa. These data indicate that the activity of manuka honey comes from multiple mechanisms of action that do not engender bacterial resistance. Importance: The threat of antimicrobial resistance to human health has prompted interest in complex, natural products with antimicrobial activity. Honey has been an effective topical wound treatment throughout history, predominantly due to its broad-spectrum antimicrobial activity. Unlike traditional antibiotics, honey-resistant bacteria have not been reported; however, honey remains underutilized in the clinic in part due to a lack of understanding of its mechanism of action. Here, we demonstrate that honey affects multiple processes in bacteria, and this is not explained by its major antibacterial components. Honey also uniquely affects bacterial membranes, and this can be exploited for combination therapy with antibiotics that are otherwise ineffective on their own. We argue that honey should be included as part of the current array of wound treatments due to its effective antibacterial activity that does not promote resistance in bacteria.]]> Tue 16 Nov 2021 15:46:30 AEDT ]]> Systematic analyses identify modes of action of ten clinically relevant biocides and antibiotic antagonism in Acinetobacter baumannii https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:54509 Tue 12 Mar 2024 17:50:03 AEDT ]]> Pacing across the membrane: the novel PACE family of efflux pumps is widespread in Gram-negative pathogens https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35003 Tue 03 Sep 2019 17:52:20 AEST ]]> Short-chain diamines are the physiological substrates of PACE family efflux pumps https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37182 Acinetobacter baumannii has rapidly emerged as a major cause of gram-negative hospital infections worldwide. A. baumannii encodes for the transport protein AceI, which confers resistance to chlorhexidine, a widely used antiseptic. AceI is also the prototype for the recently discovered proteobacterial antimicrobial compound efflux (PACE) family of transport proteins that confer resistance to a range of antibiotics and antiseptics in many gram-negative bacteria, including pathogens. The gene encoding AceI is conserved in the core genome of A. baumannii, suggesting that it has an important primordial function. This is incongruous with the sole characterized substrate of AceI, chlorhexidine, an entirely synthetic biocide produced only during the last century. Here we investigated a potential primordial function of AceI and other members of the PACE family in the transport of naturally occurring polyamines. Polyamines are abundant in living cells, where they have physiologically important functions and play multifaceted roles in bacterial infection. Gene expression studies revealed that the aceI gene is induced in A. baumannii by the short-chain diamines cadaverine and putrescine. Membrane transport experiments conducted in whole cells of A. baumannii and Escherichia coli and also in proteoliposomes showed that AceI mediates the efflux of these short-chain diamines when energized by an electrochemical gradient. Assays conducted using 8 additional diverse PACE family proteins identified 3 that also catalyze cadaverine transport. Taken together, these results demonstrate that short-chain diamines are common substrates for the PACE family of transport proteins, adding to their broad significance as a novel family of efflux pumps.]]> Thu 27 Aug 2020 12:47:49 AEST ]]> The Transcriptomic Signature of Tigecycline in Acinetobacter baumannii https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40912 Mon 25 Jul 2022 12:09:49 AEST ]]> Identification of a novel LysR family transcriptional regulator controlling acquisition of sulfur sources in Acinetobacter baumannii https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50201 Fri 07 Jul 2023 09:49:40 AEST ]]>