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Wu W, Huang J, Xu Z. Antibiotic influx and efflux in Pseudomonas aeruginosa: Regulation and therapeutic implications. Microb Biotechnol 2024; 17:e14487. [PMID: 38801351 PMCID: PMC11129675 DOI: 10.1111/1751-7915.14487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/29/2024] Open
Abstract
Pseudomonas aeruginosa is a notorious multidrug-resistant pathogen that poses a serious and growing threat to the worldwide public health. The expression of resistance determinants is exquisitely modulated by the abundant regulatory proteins and the intricate signal sensing and transduction systems in this pathogen. Downregulation of antibiotic influx porin proteins and upregulation of antibiotic efflux pump systems owing to mutational changes in their regulators or the presence of distinct inducing molecular signals represent two of the most efficient mechanisms that restrict intracellular antibiotic accumulation and enable P. aeruginosa to resist multiple antibiotics. Treatment of P. aeruginosa infections is extremely challenging due to the highly inducible mechanism of antibiotic resistance. This review comprehensively summarizes the regulatory networks of the major porin proteins (OprD and OprH) and efflux pumps (MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY) that play critical roles in antibiotic influx and efflux in P. aeruginosa. It also discusses promising therapeutic approaches using safe and efficient adjuvants to enhance the efficacy of conventional antibiotics to combat multidrug-resistant P. aeruginosa by controlling the expression levels of porins and efflux pumps. This review not only highlights the complexity of the regulatory network that induces antibiotic resistance in P. aeruginosa but also provides important therapeutic implications in targeting the inducible mechanism of resistance.
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Affiliation(s)
- Weiyan Wu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| | - Jiahui Huang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| | - Zeling Xu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
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Kristensen R, Andersen JB, Rybtke M, Jansen CU, Fritz BG, Kiilerich RO, Uhd J, Bjarnsholt T, Qvortrup K, Tolker-Nielsen T, Givskov M, Jakobsen TH. Inhibition of Pseudomonas aeruginosa quorum sensing by chemical induction of the MexEF-oprN efflux pump. Antimicrob Agents Chemother 2024; 68:e0138723. [PMID: 38189278 PMCID: PMC10848761 DOI: 10.1128/aac.01387-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 11/17/2023] [Indexed: 01/09/2024] Open
Abstract
The cell-to-cell communication system quorum sensing (QS), used by various pathogenic bacteria to synchronize gene expression and increase host invasion potentials, is studied as a potential target for persistent infection control. To search for novel molecules targeting the QS system in the Gram-negative opportunistic pathogen Pseudomonas aeruginosa, a chemical library consisting of 3,280 small compounds from LifeArc was screened. A series of 10 conjugated phenones that have not previously been reported to target bacteria were identified as inhibitors of QS in P. aeruginosa. Two lead compounds (ethylthio enynone and propylthio enynone) were re-synthesized for verification of activity and further elucidation of the mode of action. The isomeric pure Z-ethylthio enynone was used for RNA sequencing, revealing a strong inhibitor of QS-regulated genes, and the QS-regulated virulence factors rhamnolipid and pyocyanin were significantly decreased by treatment with the compounds. A transposon mutagenesis screen performed in a newly constructed lasB-gfp monitor strain identified the target of Z-ethylthio enynone in P. aeruginosa to be the MexEF-OprN efflux pump, which was further established using defined mex knockout mutants. Our data indicate that the QS inhibitory capabilities of Z-ethylthio enynone were caused by the drainage of intracellular signal molecules as a response to chemical-induced stimulation of the MexEF-oprN efflux pump, thereby inhibiting the autogenerated positive feedback and its enhanced signal-molecule synthesis.
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Affiliation(s)
- Rasmus Kristensen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Morten Rybtke
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | | | - Blaine Gabriel Fritz
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Rikke Overgaard Kiilerich
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Uhd
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Lyngby, Denmark
| | - Tim Tolker-Nielsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Michael Givskov
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Tim Holm Jakobsen
- Department of Immunology and Microbiology, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
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Liu JL, Yao J, Zhou DL, Liu B, Liu H, Li M, Zhao C, Sunahara G, Duran R. Mining-related multi-resistance genes in sulfate-reducing bacteria treatment of typical karst nonferrous metal(loid) mine tailings in China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:104753-104766. [PMID: 37707732 DOI: 10.1007/s11356-023-29203-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/02/2023] [Indexed: 09/15/2023]
Abstract
Management of tailings at metal mine smelter sites can reduce the potential hazards associated with exposure to toxic metal(loid)s and residual organic flotation reagents. In addition, microbes in the tailings harboring multi-resistance genes (e.g., tolerance to multiple antimicrobial agents) can cause high rates of morbidity and global economic problems. The potential co-selection mechanisms of antibiotic resistance genes (ARGs) and metal(loid) resistance genes (MRGs) during tailings sulfate-reducing bacteria (SRB) treatment have been poorly investigated. Samples were collected from a nonferrous metal mine tailing site treated with an established SRB protocol and were analyzed for selected geochemical properties and high throughput sequencing of 16S rRNA gene barcoding. Based on the shotgun metagenomic analysis, the bacterial domain was dominant in nonferrous metal(loid)-rich tailings treated with SRB for 12 months. KEGGs related to ARGs and MRGs were detected. Thiobacillus and Sphingomonas were the main genera carrying the bacA and mexEF resistance operons, along with Sulfuricella which were also found as the main genera carrying MRGs. The SRB treatment may mediate the distribution of numerous resistance genes. KOs based on the metagenomic database indicated that ARGs (mexNW, merD, sul, and bla) and MRGs (czcABCR and copRS genes) were found on the same contig. The SRB strains (Desulfosporosinus and Desulfotomaculum), and the acidophilic strain Acidiphilium significantly contributed to the distribution of sul genes. The functional metabolic pathways related to siderophores metabolism were largely from anaerobic genera of Streptomyces and Microbacterium. The presence of arsenate reductase, metal efflux pump, and Fe transport genes indicated that SRB treatment plays a key role in the metal(loid)s transformation. Overall, our findings show that bio-treatment is an effective tool for managing ARGs/MRGs and metals in tailings that contain numerous metal(loid) contaminants.
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Affiliation(s)
- Jian-Li Liu
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China.
| | - Jun Yao
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
| | - De-Liang Zhou
- Beijing Zhongdianyida Technology Co., Ltd, Beijing, 100190, China
| | - Bang Liu
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Houquan Liu
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Miaomiao Li
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Chenchen Zhao
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
| | - Geoffrey Sunahara
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, H9X3V9, Canada
| | - Robert Duran
- School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, Beijing Key Laboratory of Water Resources & Environmental Engineering, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, Beijing, 100083, China
- Université de Pau et des Pays de l'Adour/E2S UPPA, IPREM UMR CNRS 5254, BP 1155, 64013, Pau Cedex, France
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Cai W, Lu M, Dai W. Novel antibiotic susceptibility of an RNA polymerase α-subunit mutant in Pseudomonas aeruginosa. J Antimicrob Chemother 2023; 78:2162-2169. [PMID: 37428003 DOI: 10.1093/jac/dkad207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 06/14/2023] [Indexed: 07/11/2023] Open
Abstract
BACKGROUND RNA polymerase (RNAP) is highly conserved and essential for prokaryotic housekeeping activities, making it an important target for the development of new antibiotics. The rpoB gene, encoding a β-subunit of bacterial RNAP, has a well-known association with rifampicin resistance. However, the roles of other RNAP component genes such as rpoA, encoding an α-subunit of RNAP, in antibiotic resistance remain unexplored. OBJECTIVES To characterize the antibiotic resistance-related role of RpoA. METHODS We measured the expression of the MexEF-OprN efflux pump in an RpoA mutant using a transcriptional reporter. The MICs of various antibiotics for this RpoA mutant were determined. RESULTS We uncover a novel role of antibiotic susceptibility for an RpoA mutant in Pseudomonas aeruginosa. We found that a single amino acid substitution in RpoA resulted in reduced activity of the MexEF-OprN efflux pump, which is responsible for the exportation of various antibiotics, including ciprofloxacin, chloramphenicol, ofloxacin and norfloxacin. This attenuated efflux pump activity, caused by the RpoA mutation, conferred the bacteria further susceptibility to antibiotics regulated by MexEF-OprN. Our work further revealed that certain clinical P. aeruginosa isolates also contained the same RpoA mutation, providing clinical relevance to our findings. Our results elucidate why this new antibiotic-susceptible function of RpoA mutants would have remained undetected in conventional screens for mutants involving antibiotic resistance. CONCLUSIONS The discovery of antibiotic susceptibility in an RpoA mutant implicates a new therapeutic approach for treating clinical isolates of P. aeruginosa with RpoA mutations, using specific antibiotics regulated by MexEF-OprN. More generally, our work suggests that RpoA could serve as a promising candidate target for anti-pathogen therapeutic purposes.
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Affiliation(s)
- Wenjie Cai
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
- College of Plant Protection, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
| | - Mingqi Lu
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
- College of Plant Protection, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
| | - Weijun Dai
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China
- College of Plant Protection, Integrative Microbiology Research Center, South China Agricultural University, Guangzhou, 510642, China
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Zhao Y, Xu G, Xu Z, Guo B, Liu F. LexR Positively Regulates the LexABC Efflux Pump Involved in Self-Resistance to the Antimicrobial Di- N-Oxide Phenazine in Lysobacter antibioticus. Microbiol Spectr 2023; 11:e0487222. [PMID: 37166326 PMCID: PMC10269722 DOI: 10.1128/spectrum.04872-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 04/21/2023] [Indexed: 05/12/2023] Open
Abstract
Myxin, a di-N-oxide phenazine isolated from the soil bacterium Lysobacter antibioticus, exhibits potent activity against various microorganisms and has the potential to be developed as an agrochemical. Antibiotic-producing microorganisms have developed self-resistance mechanisms to protect themselves from autotoxicity. Antibiotic efflux is vital for such protection. Recently, we identified a resistance-nodulation-division (RND) efflux pump, LexABC, involved in self-resistance against myxin in L. antibioticus. Expression of its genes, lexABC, was induced by myxin and was positively regulated by the LysR family transcriptional regulator LexR. The molecular mechanisms, however, have not been clear. Here, LexR was found to bind to the lexABC promoter region to directly regulate expression. Moreover, myxin enhanced this binding. Molecular docking and surface plasmon resonance analysis showed that myxin bound LexR with valine and lysine residues at positions 146 (V146) and 195 (K195), respectively. Furthermore, mutation of K195 in vivo led to downregulation of the gene lexA. These results indicated that LexR sensed and bound with myxin, thereby directly activating the expression of the LexABC efflux pump and increasing L. antibioticus resistance against myxin. IMPORTANCE Antibiotic-producing bacteria exhibit various sophisticated mechanisms for self-protection against their own secondary metabolites. RND efflux pumps that eliminate antibiotics from cells are ubiquitous in Gram-negative bacteria. Myxin is a heterocyclic N-oxide phenazine with potent antimicrobial and antitumor activities produced by the soil bacterium L. antibioticus. The RND pump LexABC contributes to the self-resistance of L. antibioticus against myxin. Herein, we report a mechanism involving the LysR family regulator LexR that binds to myxin and directly activates the LexABC pump. Further study on self-resistance mechanisms could help the investigation of strategies to deal with increasing bacterial antibiotic resistance and enable the discovery of novel natural products with resistance genes as selective markers.
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Affiliation(s)
- Yangyang Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
- School of Plant Protection, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, Hainan University, Haikou, China
| | - Gaoge Xu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Zhizhou Xu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
- College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Nanjing Agricultural University, Nanjing, China
| | - Baodian Guo
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
| | - Fengquan Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety, State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, China
- School of Plant Protection, Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education, Hainan University, Haikou, China
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Yamasaki S, Zwama M, Yoneda T, Hayashi-Nishino M, Nishino K. Drug resistance and physiological roles of RND multidrug efflux pumps in Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001322. [PMID: 37319001 PMCID: PMC10333786 DOI: 10.1099/mic.0.001322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/18/2023] [Indexed: 06/17/2023]
Abstract
Drug efflux pumps transport antimicrobial agents out of bacteria, thereby reducing the intracellular antimicrobial concentration, which is associated with intrinsic and acquired bacterial resistance to these antimicrobials. As genome analysis has advanced, many drug efflux pump genes have been detected in the genomes of bacterial species. In addition to drug resistance, these pumps are involved in various essential physiological functions, such as bacterial adaptation to hostile environments, toxin and metabolite efflux, biofilm formation and quorum sensing. In Gram-negative bacteria, efflux pumps in the resistance–nodulation–division (RND) superfamily play a clinically important role. In this review, we focus on Gram-negative bacteria, including Salmonella enterica , Escherichia coli and Pseudomonas aeruginosa , and discuss the role of RND efflux pumps in drug resistance and physiological functions.
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Affiliation(s)
- Seiji Yamasaki
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Martijn Zwama
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Tomohiro Yoneda
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mitsuko Hayashi-Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kunihiko Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research, 2-8 Yamadaoka, Osaka University, Suita, Osaka 565-0871, Japan
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Virulence Induction in Pseudomonas aeruginosa under Inorganic Phosphate Limitation: a Proteomics Perspective. Microbiol Spectr 2022; 10:e0259022. [PMID: 36354317 PMCID: PMC9769906 DOI: 10.1128/spectrum.02590-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Inorganic phosphate (Pi) is a central nutrient and signal molecule for bacteria. Pi limitation was shown to increase the virulence of several phylogenetically diverse pathogenic bacteria with different lifestyles. Hypophosphatemia enhances the risk of death in patients due to general bacteremia and was observed after surgical injury in humans. Phosphate therapy, or the reduction of bacterial virulence by the administration of Pi or phosphate-containing compounds, is a promising anti-infective therapy approach that will not cause cytotoxicity or the emergence of antibiotic-resistant strains. The proof of concept of phosphate therapy has been obtained using primarily Pseudomonas aeruginosa (PA). However, a detailed understanding of Pi-induced changes at protein levels is missing. Using pyocyanin production as proxy, we show that the Pi-mediated induction of virulence is a highly cooperative process that occurs between 0.2 to 0.6 mM Pi. We present a proteomics study of PA grown in minimal medium supplemented with either 0.2 mM or 1 mM Pi and rich medium. About half of the predicted PA proteins could be quantified. Among the 1,471 dysregulated proteins comparing growth in 0.2 mM to 1 mM Pi, 1,100 were depleted under Pi-deficient conditions. Most of these proteins are involved in general and energy metabolism, different biosynthetic and catabolic routes, or transport. Pi depletion caused accumulation of proteins that belong to all major families of virulence factors, including pyocyanin synthesis, secretion systems, quorum sensing, chemosensory signaling, and the secretion of proteases, phospholipases, and phosphatases, which correlated with an increase in exoenzyme production and antibacterial activity. IMPORTANCE Antibiotics are our main weapons to fight pathogenic bacteria, but the increase in antibiotic-resistant strains and their consequences represents a major global health challenge, revealing the necessity to develop alternative antimicrobial strategies that do not involve the bacterial killing or growth inhibition. P. aeruginosa has been placed second on the global priority list to guide research on the development of new antibiotics. One of the most promising alternative strategies is the phosphate therapy for which the proof of concept has been obtained for P. aeruginosa. This article reports the detailed changes at the protein levels comparing P. aeruginosa grown under Pi-abundant and Pi-depleted conditions. These data describe in detail the molecular mechanisms underlying phosphate therapy. Apart from Pi, several other phosphate-containing compounds have been used for phosphate therapy and this study will serve as a reference for comparative studies aimed at evaluating the effect of alternative compounds.
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Transcriptional Response of Candida auris to the Mrr1 Inducers Methylglyoxal and Benomyl. mSphere 2022; 7:e0012422. [PMID: 35473297 PMCID: PMC9241502 DOI: 10.1128/msphere.00124-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida auris is an urgent threat to human health due to its rapid spread in health care settings and its repeated development of multidrug resistance. Diseases that increase risk for C. auris infection, such as diabetes, kidney failure, or immunocompromising conditions, are associated with elevated levels of methylglyoxal (MG), a reactive dicarbonyl compound derived from several metabolic processes. In other Candida species, expression of MG reductase enzymes that catabolize and detoxify MG are controlled by Mrr1, a multidrug resistance-associated transcription factor, and MG induces Mrr1 activity. Here, we used transcriptomics and genetic assays to determine that C. aurisMRR1a contributes to MG resistance, and that the main Mrr1a targets are an MG reductase and MDR1, which encodes a drug efflux protein. The C. auris Mrr1a regulon is smaller than Mrr1 regulons described in other species. In addition to MG, benomyl (BEN), a known Mrr1 stimulus, induces C. auris Mrr1 activity, and characterization of the MRR1a-dependent and -independent transcriptional responses revealed substantial overlap in genes that were differentially expressed in response to each compound. Additionally, we found that an MRR1 allele specific to one C. auris phylogenetic clade, clade III, encodes a hyperactive Mrr1 variant, and this activity correlated with higher MG resistance. C. aurisMRR1a alleles were functional in Candida lusitaniae and were inducible by BEN, but not by MG, suggesting that the two Mrr1 inducers act via different mechanisms. Together, the data presented in this work contribute to the understanding of Mrr1 activity and MG resistance in C. auris. IMPORTANCECandida auris is a fungal pathogen that has spread since its identification in 2009 and is of concern due to its high incidence of resistance against multiple classes of antifungal drugs. In other Candida species, the transcription factor Mrr1 plays a major role in resistance against azole antifungals and other toxins. More recently, Mrr1 has been recognized to contribute to resistance to methylglyoxal (MG), a toxic metabolic product that is often elevated in different disease states. MG can activate Mrr1 and its induction of Mdr1 which can protect against diverse challenges. The significance of this work lies in showing that MG is also an inducer of Mrr1 in C. auris, and that one of the major pathogenic C. auris lineages has an activating Mrr1 mutation that confers protection against MG.
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Huang L, Wu C, Gao H, Xu C, Dai M, Huang L, Hao H, Wang X, Cheng G. Bacterial Multidrug Efflux Pumps at the Frontline of Antimicrobial Resistance: An Overview. Antibiotics (Basel) 2022; 11:antibiotics11040520. [PMID: 35453271 PMCID: PMC9032748 DOI: 10.3390/antibiotics11040520] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/01/2022] [Accepted: 04/08/2022] [Indexed: 02/06/2023] Open
Abstract
Multidrug efflux pumps function at the frontline to protect bacteria against antimicrobials by decreasing the intracellular concentration of drugs. This protective barrier consists of a series of transporter proteins, which are located in the bacterial cell membrane and periplasm and remove diverse extraneous substrates, including antimicrobials, organic solvents, toxic heavy metals, etc., from bacterial cells. This review systematically and comprehensively summarizes the functions of multiple efflux pumps families and discusses their potential applications. The biological functions of efflux pumps including their promotion of multidrug resistance, biofilm formation, quorum sensing, and survival and pathogenicity of bacteria are elucidated. The potential applications of efflux pump-related genes/proteins for the detection of antibiotic residues and antimicrobial resistance are also analyzed. Last but not least, efflux pump inhibitors, especially those of plant origin, are discussed.
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10
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Duncan D, Auclair K. Itaconate: an antimicrobial metabolite of macrophages. CAN J CHEM 2022. [DOI: 10.1139/cjc-2021-0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Itaconate is a conjugated 1,4-dicarboxylate produced by macrophages. This small molecule has recently received increasing attention due to its role in modulating the immune response of macrophages upon exposure to pathogens. Itaconate has also been proposed to play an antimicrobial function; however, this has not been explored as intensively. Consistent with the latter, itaconate is known to show antibacterial activity in vitro and was reported to inhibit isocitrate lyase, an enzyme required for survival of bacterial pathogens in mammalian systems. Recent studies have revealed bacterial growth inhibition under biologically relevant conditions. In addition, an antimicrobial role for itaconate is substantiated by the high concentration of itaconate found in bacteria-containing vacuoles, and by the production of itaconate-degrading enzymes in pathogens such as Salmonella enterica ser. Typhimurium, Pseudomonas aeruginosa, and Yersinia pestis. This review describes the current state of literature in understanding the role of itaconate as an antimicrobial agent in host–pathogen interactions.
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Affiliation(s)
- Dustin Duncan
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
| | - Karine Auclair
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
- Department of Chemistry, McGill University, Montreal, QC H3A 0B8, Canada
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11
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Kotecka K, Kawalek A, Kobylecki K, Bartosik AA. The AraC-Type Transcriptional Regulator GliR (PA3027) Activates Genes of Glycerolipid Metabolism in Pseudomonas aeruginosa. Int J Mol Sci 2021; 22:5066. [PMID: 34064685 PMCID: PMC8151288 DOI: 10.3390/ijms22105066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/04/2021] [Accepted: 05/06/2021] [Indexed: 12/13/2022] Open
Abstract
Pseudomonas aeruginosa encodes a large set of transcriptional regulators (TRs) that modulate and manage cellular metabolism to survive in variable environmental conditions including that of the human body. The AraC family regulators are an abundant group of TRs in bacteria, mostly acting as gene expression activators, controlling diverse cellular functions (e.g., carbon metabolism, stress response, and virulence). The PA3027 protein from P. aeruginosa has been classified in silico as a putative AraC-type TR. Transcriptional profiling of P. aeruginosa PAO1161 overexpressing PA3027 revealed a spectacular increase in the mRNA levels of PA3026-PA3024 (divergent to PA3027), PA3464, and PA3342 genes encoding proteins potentially involved in glycerolipid metabolism. Concomitantly, chromatin immunoprecipitation-sequencing (ChIP-seq) analysis revealed that at least 22 regions are bound by PA3027 in the PAO1161 genome. These encompass promoter regions of PA3026, PA3464, and PA3342, showing the major increase in expression in response to PA3027 excess. In Vitro DNA binding assay confirmed interactions of PA3027 with these regions. Furthermore, promoter-reporter assays in a heterologous host showed the PA3027-dependent activation of the promoter of the PA3026-PA3024 operon. Two motifs representing the preferred binding sites for PA3027, one localized upstream and one overlapping with the -35 promoter sequence, were identified in PA3026p and our data indicate that both motifs are required for full activation of this promoter by PA3027. Overall, the presented data show that PA3027 acts as a transcriptional regulator in P. aeruginosa, activating genes likely engaged in glycerolipid metabolism. The GliR name, from a glycerolipid metabolism regulator, is proposed for PA3027 of P. aeruginosa.
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Affiliation(s)
| | | | | | - Aneta Agnieszka Bartosik
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland; (K.K.); (A.K.); (K.K.)
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12
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Kusumawardhani H, Furtwängler B, Blommestijn M, Kaltenytė A, van der Poel J, Kolk J, Hosseini R, de Winde JH. Adaptive Laboratory Evolution Restores Solvent Tolerance in Plasmid-Cured Pseudomonas putida S12: a Molecular Analysis. Appl Environ Microbiol 2021; 87:e00041-21. [PMID: 33674430 PMCID: PMC8091024 DOI: 10.1128/aem.00041-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/24/2021] [Indexed: 11/23/2022] Open
Abstract
Pseudomonas putida S12 is inherently solvent tolerant and constitutes a promising platform for biobased production of aromatic compounds and biopolymers. The megaplasmid pTTS12 of P. putida S12 carries several gene clusters involved in solvent tolerance, and the removal of this megaplasmid caused a significant reduction in solvent tolerance. In this study, we succeeded in restoring solvent tolerance in plasmid-cured P. putida S12 using adaptive laboratory evolution (ALE), underscoring the innate solvent tolerance of this strain. Whole-genome sequencing identified several single nucleotide polymorphisms (SNPs) and a mobile element insertion enabling ALE-derived strains to survive and sustain growth in the presence of a high toluene concentration (10% [vol/vol]). We identified mutations in an RND efflux pump regulator, arpR, that resulted in constitutive upregulation of the multifunctional efflux pump ArpABC. SNPs were also found in the intergenic region and subunits of ATP synthase, RNA polymerase subunit β', a global two-component regulatory system (GacA/GacS), and a putative AraC family transcriptional regulator, Afr. Transcriptomic analysis further revealed a constitutive downregulation of energy-consuming activities in ALE-derived strains, such as flagellar assembly, FoF1 ATP synthase, and membrane transport proteins. In summary, constitutive expression of a solvent extrusion pump in combination with high metabolic flexibility enabled the restoration of the solvent tolerance trait in P. putida S12 lacking its megaplasmid.IMPORTANCE Sustainable production of high-value chemicals can be achieved by bacterial biocatalysis. However, bioproduction of biopolymers and aromatic compounds may exert stress on the microbial production host and limit the resulting yield. Having a solvent tolerance trait is highly advantageous for microbial hosts used in the biobased production of aromatics. The presence of a megaplasmid has been linked to the solvent tolerance trait of Pseudomonas putida; however, the extent of innate, intrinsic solvent tolerance in this bacterium remained unclear. Using adaptive laboratory evolution, we successfully adapted the plasmid-cured P. putida S12 strain to regain its solvent tolerance. Through these adapted strains, we began to clarify the causes, origins, limitations, and trade-offs of the intrinsic solvent tolerance in P. putida This work sheds light on the possible genetic engineering targets to enhance solvent tolerance in Pseudomonas putida as well as other bacteria.
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Affiliation(s)
| | | | | | - Adelė Kaltenytė
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Jaap van der Poel
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Jan Kolk
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Rohola Hosseini
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
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13
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Ngoepe MP, Moeno S. Evaluation of Pipemidic Acid Derivatives for Potential Antimicrobial Activity Application: In silico Studies on Bioactivity. LETT DRUG DES DISCOV 2021. [DOI: 10.2174/1570180817999200730165219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Pipemidic acid is a broad-spectrum quinolone antibacterial agent for the
treatment of chronic urinary tract infections against both gram-positive and gram-negative bacteria.
Both quinolone and fluoroquinolone antibiotics have been useful in combating bacterial infections.
However, patients suffer severe side effects when they stop taking the medication. The piperazinyl
region of pipemidic acid is highly responsible for the side effects.
Objective:
The objective of this study is to design new compounds in which the piperazinyl region is
masked by way of conjugation to benzoic acid derivatives.
Methods:
In silico studies were conducted using AutoDockTools software for ligand-protein
docking. The docking scores were compared to the parent pipemidic acid docked to Bacterial DNA
(deoxyribonucleic acid) gyrase and GABA (gamma-Aminobutyric acid) receptor from the PDB
(Protein Data Bank) database. Sites of metabolism, biological activity, quantum chemical
descriptors, and ADME (absorption, distribution, metabolism, and excretion) property predictions
for each designed ligand were also evaluated.
Results:
The docking studies and biological activity predictions showed good anti-infective properties
(ligand PAR03) whilst also suggesting a reduction in GABA receptor agonist activity. The performance
of PAR03 correlates with its electronic properties showing electrophilic character (can
generate Reactive Electrophilic Species (RES)).
Conclusion:
The results from this study indicate that modification of the piperazinyl region of pipemidic
acid can be an effective way to improve the drug potency whilst also ensuring reduction of
the associated side effects.
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Affiliation(s)
- Mpho Phehello Ngoepe
- Department of Oral Biological Sciences, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
| | - Sharon Moeno
- Department of Oral Biological Sciences, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
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Xu C, Liu H, Pan X, Ma Z, Wang D, Zhang X, Zhu G, Bai F, Cheng Z, Wu W, Jin Y. Mechanisms for Development of Ciprofloxacin Resistance in a Clinical Isolate of Pseudomonas aeruginosa. Front Microbiol 2021; 11:598291. [PMID: 33488544 PMCID: PMC7819972 DOI: 10.3389/fmicb.2020.598291] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/24/2020] [Indexed: 12/21/2022] Open
Abstract
Treatment of infections by Pseudomonas aeruginosa is difficult due to its high intrinsic and acquired antibiotic resistance. Upon colonization in the human hosts, P. aeruginosa accumulates genetic mutations that confer the bacterium antibiotic resistance and ability to better live in the host environment. Characterizing the evolutionary traits would provide important insights into the development of effective combinatory antibiotic therapies to cure P. aeruginosa infections. In this work, we performed a detailed analysis of the molecular mechanisms by which a clinical isolate (CSP18) yields a ciprofloxacin-resistant derivative (CRP42). Genomic DNA re-sequencing and RNAseq were carried out to compare the genomic mutational signature and transcriptional profiles between the two isolates. The results indicated that D87G mutation in GyrA, together with MexEF-OprN hyper-expression caused by F7S mutation in MexS, was responsible for the increased resistance to ciprofloxacin in the isolate CRP42. Further simulation of CRP42 by gene editing in CSP18 demonstrated that D87G mutation in GyrA rendered CSP18 a fourfold increase in minimum inhibitory concentration against ciprofloxacin, while F7S mutation in MexS conferred an additional eightfold increase. Our experimental results demonstrate for the first time that the clinically relevant F7S point mutation in MexS results in hyper-expression of the mexEF-oprN and thus confers P. aeruginosa resistance to ciprofloxacin.
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Affiliation(s)
- Congjuan Xu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Huimin Liu
- Tianjin Union Medical Center, Nankai University Affiliated Hospital, Tianjin, China
| | - Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhenzhen Ma
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Dan Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xinxin Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Guangbo Zhu
- Tianjin Union Medical Center, Nankai University Affiliated Hospital, Tianjin, China
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
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15
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Biermann AR, Demers EG, Hogan DA. Mrr1 regulation of methylglyoxal catabolism and methylglyoxal-induced fluconazole resistance in Candida lusitaniae. Mol Microbiol 2020; 115:116-130. [PMID: 33319423 DOI: 10.1111/mmi.14604] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/26/2020] [Accepted: 09/05/2020] [Indexed: 12/11/2022]
Abstract
Transcription factor Mrr1, best known for its regulation of Candida azole resistance genes such as MDR1, regulates other genes that are poorly characterized. Among the other Mrr1-regulated genes are putative methylglyoxal reductases. Methylglyoxal (MG) is a toxic metabolite that is elevated in diabetes, uremia, and sepsis, which are diseases that increase the risk for candidiasis, and MG serves as a regulatory signal in diverse organisms. Our studies in Clavispora lusitaniae, also known as Candida lusitaniae, showed that Mrr1 regulates expression of two paralogous MG reductases, MGD1 and MGD2, and that both participate in MG resistance and MG catabolism. Exogenous MG increased Mrr1-dependent expression of MGD1 and MGD2 as well as expression of MDR1, which encodes an efflux pump that exports fluconazole. MG improved growth in the presence of fluconazole and this was largely Mrr1-dependent with contributions from a secondary transcription factor, Cap1. Increased fluconazole resistance was also observed in mutants lacking Glo1, a Mrr1-independent MG catabolic enzyme. Isolates from other Candida species displayed heterogeneity in MG resistance and MG stimulation of azole resistance. We propose endogenous and host-derived MG can induce MDR1 and other Mrr1-regulated genes causing increased drug resistance, which may contribute to some instances of fungal treatment failure.
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Affiliation(s)
- Amy R Biermann
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Elora G Demers
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Deborah A Hogan
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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16
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Riquelme SA, Liimatta K, Wong Fok Lung T, Fields B, Ahn D, Chen D, Lozano C, Sáenz Y, Uhlemann AC, Kahl BC, Britto CJ, DiMango E, Prince A. Pseudomonas aeruginosa Utilizes Host-Derived Itaconate to Redirect Its Metabolism to Promote Biofilm Formation. Cell Metab 2020; 31:1091-1106.e6. [PMID: 32428444 PMCID: PMC7272298 DOI: 10.1016/j.cmet.2020.04.017] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/31/2020] [Accepted: 04/21/2020] [Indexed: 01/23/2023]
Abstract
The bacterium Pseudomonas aeruginosa is especially pathogenic, often being associated with intractable pneumonia and high mortality. How P. aeruginosa avoids immune clearance and persists in the inflamed human airway remains poorly understood. In this study, we show that P. aeruginosa can exploit the host immune response to maintain infection. Notably, unlike other opportunistic bacteria, we found that P. aeruginosa alters its metabolic and immunostimulatory properties in response to itaconate, an abundant host-derived immunometabolite in the infected lung. Itaconate induces bacterial membrane stress, resulting in downregulation of lipopolysaccharides (LPS) and upregulation of extracellular polysaccharides (EPS). These itaconate-adapted P. aeruginosa accumulate lptD mutations, which favor itaconate assimilation and biofilm formation. EPS, in turn, induces itaconate production by myeloid cells, both in the airway and systemically, skewing the host immune response to one permissive of chronic infection. Thus, the metabolic versatility of P. aeruginosa needs to be taken into account when designing therapies.
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Affiliation(s)
| | - Kalle Liimatta
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | | | - Blanche Fields
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Danielle Ahn
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - David Chen
- Department of Pediatrics, Columbia University, New York, NY 10032, USA
| | - Carmen Lozano
- Area de Microbiología Molecular, Centro de Investigación Biomédica de la Rioja (CIBIR), Microbiología Molecular, Logroño, LG 26006, Spain
| | - Yolanda Sáenz
- Area de Microbiología Molecular, Centro de Investigación Biomédica de la Rioja (CIBIR), Microbiología Molecular, Logroño, LG 26006, Spain
| | - Anne-Catrin Uhlemann
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Barbara C Kahl
- Institute of Medical Microbiology, University Hospital Münster, Münster 48149, Germany
| | - Clemente J Britto
- Section of Pulmonary, Critical Care, and Sleep Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Emily DiMango
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Alice Prince
- Department of Pediatrics, Columbia University, New York, NY 10032, USA.
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17
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Kim S, Kim SH, Ahn J, Jo I, Lee ZW, Choi SH, Ha NC. Crystal Structure of the Regulatory Domain of MexT, a Transcriptional Activator of the MexEFOprN Efflux Pump in Pseudomonas aeruginosa. Mol Cells 2019; 42:850-857. [PMID: 31722511 PMCID: PMC6939650 DOI: 10.14348/molcells.2019.0168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/06/2019] [Accepted: 10/07/2019] [Indexed: 12/02/2022] Open
Abstract
The Gram-negative opportunistic pathogen, Pseudomonas aeruginosa , has multiple multidrug efflux pumps. MexT, a LysR-type transcriptional regulator, functions as a transcriptional activator of the MexEF-OprN efflux system. MexT consists of an N-terminal DNA-binding domain and a C-terminal regulatory domain (RD). Little is known regarding MexT ligands and its mechanism of activation. We elucidated the crystal structure of the MexT RD at 2.0 Å resolution. The structure comprised two protomer chains in a dimeric arrangement. MexT possessed an arginine-rich region and a hydrophobic patch lined by a variable loop, both of which are putative ligand-binding sites. The three-dimensional structure of MexT provided clues to the interacting ligand structure. A DNase I footprinting assay of full-length MexT identified two MexT-binding sequence in the mexEF oprN promoter. Our findings enhance the understanding of the regulation of MexT-dependent activation of efflux pumps.
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Affiliation(s)
- Suhyeon Kim
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Songhee H. Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826,
Korea
| | - Jinsook Ahn
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Inseong Jo
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Zee-Won Lee
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Sang Ho Choi
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
| | - Nam-Chul Ha
- Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826,
Korea
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18
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Morrison JM, Chojnacki M, Fadrowski JJ, Bauza C, Dunman PM, Dudas RA, Goldenberg NA, Berman DM. Serum-Associated Antibiotic Tolerance in Pediatric Clinical Isolates of Pseudomonas aeruginosa. J Pediatric Infect Dis Soc 2019; 9:671-679. [PMID: 31886511 PMCID: PMC7974018 DOI: 10.1093/jpids/piz094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND When grown in human serum, laboratory isolates of Pseudomonas aeruginosa exhibit tolerance to antibiotics at inhibitory concentrations. This phenomenon, known as serum-associated antibiotic tolerance (SAT), could lead to clinical treatment failure of pseudomonal infections. Our purpose in this study was to determine the prevalence and clinical impact of SAT in Pseudomonas isolates in hospitalized children. METHODS The SAT phenotype was assessed in patients aged <18 years admitted with respiratory or blood cultures positive for P. aeruginosa. The SAT phenotype was a priori defined as a ≥2-log increase in colony-forming units when grown in human serum compared with Luria-Bertani medium in the presence of minocycline or tobramycin. RESULTS SAT was detected in 29 (64%) patients. Fourteen patients each (34%) had cystic fibrosis (CF) and tracheostomies. Patient demographics and comorbidities did not differ by SAT status. Among CF patients, SAT was associated with longer duration of intravenous antibiotics (10 days vs 5 days; P < .01). CONCLUSIONS This study establishes that SAT exists in P. aeruginosa from human serum and may be a novel factor that contributes to differences in clinical outcomes. Future research should investigate the mechanisms that contribute to SAT in order to identify novel targets for adjunctive antimicrobial therapies.
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Affiliation(s)
- John M Morrison
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA,Department of Medicine, Division of Hospital Medicine, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA,Correspondence: John M. Morrison, 601 Fifth Street South Suite 501, Saint Petersburg, FL 33701 ()
| | - Michaelle Chojnacki
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Jeffrey J Fadrowski
- Department of Pediatrics, Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Colleen Bauza
- Department of Health Informatics, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
| | - Paul M Dunman
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Robert A Dudas
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA,Department of Medicine, Division of Hospital Medicine, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
| | - Neil A Goldenberg
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA, and All Children’s Research Institute, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
| | - David M Berman
- Department of Medicine, Division of Infectious Diseases, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, USA
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Hill IT, Tallo T, Dorman MJ, Dove SL. Loss of RNA Chaperone Hfq Unveils a Toxic Pathway in Pseudomonas aeruginosa. J Bacteriol 2019; 201:e00232-19. [PMID: 31358608 PMCID: PMC6755729 DOI: 10.1128/jb.00232-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/22/2019] [Indexed: 12/17/2022] Open
Abstract
Hfq is an RNA chaperone that serves as a master regulator of bacterial physiology. Here we show that in the opportunistic pathogen Pseudomonas aeruginosa, the loss of Hfq can result in a dramatic reduction in growth in a manner that is dependent upon MexT, a transcription regulator that governs antibiotic resistance in this organism. Using a combination of chromatin immunoprecipitation with high-throughput sequencing and transposon insertion sequencing, we identify the MexT-activated genes responsible for mediating the growth defect of hfq mutant cells. These include a newly identified MexT-controlled gene that we call hilR We demonstrate that hilR encodes a small protein that is acutely toxic to wild-type cells when produced ectopically. Furthermore, we show that hilR expression is negatively regulated by Hfq, offering a possible explanation for the growth defect of hfq mutant cells. Finally, we present evidence that the expression of MexT-activated genes is dependent upon GshA, an enzyme involved in the synthesis of glutathione. Our findings suggest that Hfq can influence the growth of P. aeruginosa by limiting the toxic effects of specific MexT-regulated genes. Moreover, our results identify glutathione to be a factor important for the in vivo activity of MexT.IMPORTANCE Here we show that the conserved RNA chaperone Hfq is important for the growth of the opportunistic pathogen Pseudomonas aeruginosa We found that the growth defect of hfq mutant cells is dependent upon the expression of genes that are under the control of the transcription regulator MexT. These include a gene that we refer to as hilR, which we show is negatively regulated by Hfq and encodes a small protein that can be toxic when ectopically produced in wild-type cells. Thus, Hfq can influence the growth of P. aeruginosa by limiting the toxic effects of MexT-regulated genes, including one encoding a previously unrecognized small protein. We also show that MexT activity depends on an enzyme that synthesizes glutathione.
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Affiliation(s)
- Ian T Hill
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas Tallo
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew J Dorman
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Simon L Dove
- Division of Infectious Diseases, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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20
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Cinnamaldehyde Induces Expression of Efflux Pumps and Multidrug Resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2019; 63:AAC.01081-19. [PMID: 31383658 DOI: 10.1128/aac.01081-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/27/2019] [Indexed: 01/23/2023] Open
Abstract
Essential oils or their components are increasingly used to fight bacterial infections. Cinnamaldehyde (CNA), the main constituent of cinnamon bark oil, has demonstrated interesting properties in vitro against various pathogens, including Pseudomonas aeruginosa In the present study, we investigated the mechanisms and possible therapeutic consequences of P. aeruginosa adaptation to CNA. Exposure of P. aeruginosa PA14 to subinhibitory concentrations of CNA caused a strong albeit transient increase in the expression of operons that encode the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY/OprM. This multipump activation enhanced from 2- to 8-fold the resistance (MIC) of PA14 to various antipseudomonal antibiotics, including meropenem, ceftazidime, tobramycin, and ciprofloxacin. CNA-induced production of pump MexAB-OprM was found to play a major role in the adaption of P. aeruginosa to the electrophilic biocide, through the NalC regulatory pathway. CNA was progressively transformed by bacteria into the less toxic metabolite cinnamic alcohol (CN-OH), via yet undetermined detoxifying mechanisms. In conclusion, the use of cinnamon bark oil or cinnamaldehyde as adjunctive therapy to treat P. aeruginosa infections may potentially have antagonistic effects if combined with antibiotics because of Mex pump activation.
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21
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Seven-Year Trend of Antimicrobial Resistance of Acinetobacter and Pseudomonas spp. Causing Bloodstream Infections: A Retrospective Study from Shiraz, Southern Iran. Jundishapur J Microbiol 2019. [DOI: 10.5812/jjm.85819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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22
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High-resolution in situ transcriptomics of Pseudomonas aeruginosa unveils genotype independent patho-phenotypes in cystic fibrosis lungs. Nat Commun 2018; 9:3459. [PMID: 30150613 PMCID: PMC6110831 DOI: 10.1038/s41467-018-05944-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/30/2018] [Indexed: 12/30/2022] Open
Abstract
Life-long bacterial infections in cystic fibrosis (CF) airways constitute an excellent model both for persistent infections and for microbial adaptive evolution in complex dynamic environments. Using high-resolution transcriptomics applied on CF sputum, we profile transcriptional phenotypes of Pseudomonas aeruginosa populations in patho-physiological conditions. Here we show that the soft-core genome of genetically distinct populations, while maintaining transcriptional flexibility, shares a common expression program tied to the lungs environment. We identify genetically independent traits defining P. aeruginosa physiology in vivo, documenting the connection between several previously identified mutations in CF isolates and some of the convergent phenotypes known to develop in later stages of the infection. In addition, our data highlight to what extent this organism can exploit its extensive repertoire of physiological pathways to acclimate to a new niche and suggest how alternative nutrients produced in the lungs may be utilized in unexpected metabolic contexts.
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Housseini B Issa K, Phan G, Broutin I. Functional Mechanism of the Efflux Pumps Transcription Regulators From Pseudomonas aeruginosa Based on 3D Structures. Front Mol Biosci 2018; 5:57. [PMID: 29971236 PMCID: PMC6018408 DOI: 10.3389/fmolb.2018.00057] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/31/2018] [Indexed: 01/19/2023] Open
Abstract
Bacterial antibiotic resistance is a worldwide health problem that deserves important research attention in order to develop new therapeutic strategies. Recently, the World Health Organization (WHO) classified Pseudomonas aeruginosa as one of the priority bacteria for which new antibiotics are urgently needed. In this opportunistic pathogen, antibiotics efflux is one of the most prevalent mechanisms where the drug is efficiently expulsed through the cell-wall. This resistance mechanism is highly correlated to the expression level of efflux pumps of the resistance-nodulation-cell division (RND) family, which is finely tuned by gene regulators. Thus, it is worthwhile considering the efflux pump regulators of P. aeruginosa as promising therapeutical targets alternative. Several families of regulators have been identified, including activators and repressors that control the genetic expression of the pumps in response to an extracellular signal, such as the presence of the antibiotic or other environmental modifications. In this review, based on different crystallographic structures solved from archetypal bacteria, we will first focus on the molecular mechanism of the regulator families involved in the RND efflux pump expression in P. aeruginosa, which are TetR, LysR, MarR, AraC, and the two-components system (TCS). Finally, the regulators of known structure from P. aeruginosa will be presented.
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Affiliation(s)
- Karim Housseini B Issa
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Gilles Phan
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Isabelle Broutin
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
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Neuberger A, Du D, Luisi BF. Structure and mechanism of bacterial tripartite efflux pumps. Res Microbiol 2018; 169:401-413. [PMID: 29787834 DOI: 10.1016/j.resmic.2018.05.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 02/20/2018] [Accepted: 05/14/2018] [Indexed: 12/22/2022]
Abstract
Efflux pumps are membrane proteins which contribute to multi-drug resistance. In Gram-negative bacteria, some of these pumps form complex tripartite assemblies in association with an outer membrane channel and a periplasmic membrane fusion protein. These tripartite machineries span both membranes and the periplasmic space, and they extrude from the bacterium chemically diverse toxic substrates. In this chapter, we summarise current understanding of the structural architecture, functionality, and regulation of tripartite multi-drug efflux assemblies.
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Affiliation(s)
- Arthur Neuberger
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Dijun Du
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
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López-Causapé C, Cabot G, Del Barrio-Tofiño E, Oliver A. The Versatile Mutational Resistome of Pseudomonas aeruginosa. Front Microbiol 2018; 9:685. [PMID: 29681898 PMCID: PMC5897538 DOI: 10.3389/fmicb.2018.00685] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/23/2018] [Indexed: 12/11/2022] Open
Abstract
One of the most striking features of Pseudomonas aeruginosa is its outstanding capacity for developing antimicrobial resistance to nearly all available antipseudomonal agents through the selection of chromosomal mutations, leading to the failure of the treatment of severe hospital-acquired or chronic infections. Recent whole-genome sequencing (WGS) data obtained from in vitro assays on the evolution of antibiotic resistance, in vivo monitoring of antimicrobial resistance development, analysis of sequential cystic fibrosis isolates, and characterization of widespread epidemic high-risk clones have provided new insights into the evolutionary dynamics and mechanisms of P. aeruginosa antibiotic resistance, thus motivating this review. Indeed, the analysis of the WGS mutational resistome has proven to be useful for understanding the evolutionary dynamics of classical resistance pathways and to describe new mechanisms for the majority of antipseudomonal classes, including β-lactams, aminoglycosides, fluoroquinolones, or polymixins. Beyond addressing a relevant scientific question, the analysis of the P. aeruginosa mutational resistome is expected to be useful, together with the analysis of the horizontally-acquired resistance determinants, for establishing the antibiotic resistance genotype, which should correlate with the antibiotic resistance phenotype and as such, it should be useful for the design of therapeutic strategies and for monitoring the efficacy of administered antibiotic treatments. However, further experimental research and new bioinformatics tools are still needed to overcome the interpretation limitations imposed by the complex interactions (including those leading to collateral resistance or susceptibility) between the 100s of genes involved in the mutational resistome, as well as the frequent difficulties for differentiating relevant mutations from simple natural polymorphisms.
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Affiliation(s)
- Carla López-Causapé
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Gabriel Cabot
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Ester Del Barrio-Tofiño
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Antonio Oliver
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
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