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Alatawneh N, Thangaraj M, Meijler MM. Inhibition of Acinetobacter nosocomialis twitching motility by quinolones produced by Pseudomonas aeruginosa. Chem Commun (Camb) 2024; 60:12533-12536. [PMID: 39380548 DOI: 10.1039/d4cc04270k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2024]
Abstract
Twitching motility in A. nosocomialis is a key virulence factor linked to antibiotic resistance and pathogenicity. This study revealed that the Pseudomonas quinolone signal (PQS) and hydroxy-containing quinolones significantly inhibit motility without affecting bacterial growth, highlighting their potential as targets for controlling bacterial virulence.
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Affiliation(s)
- Nadeem Alatawneh
- Department of Chemistry and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
| | - Manikandan Thangaraj
- Department of Chemistry and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
| | - Michael M Meijler
- Department of Chemistry and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Be'er Sheva, Israel.
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2
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Ren J, Wang M, Zhou W, Liu Z. Efflux pumps as potential targets for biofilm inhibition. Front Microbiol 2024; 15:1315238. [PMID: 38596384 PMCID: PMC11002903 DOI: 10.3389/fmicb.2024.1315238] [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] [Received: 10/10/2023] [Accepted: 01/26/2024] [Indexed: 04/11/2024] Open
Abstract
Biofilms account for a great deal of infectious diseases and contribute significantly to antimicrobial resistance. Efflux pumps confer antimicrobial resistance to microorganisms and involve multiple processes of biofilm formation. Efflux pump inhibitors (EPIs) are attracting considerable attention as a biofilm inhibition strategy. The regulatory functions of efflux pumps in biofilm formation such as mediating adherence, quorum sensing (QS) systems, and the expression of biofilm-associated genes have been increasingly identified. The versatile properties confer efflux pumps both positive and negative effects on biofilm formation. Furthermore, the expression and function of efflux pumps in biofilm formation are species-specific. Therefore, this review aims to detail the double-edged sword role of efflux pumps in biofilm formation to provide potential inhibition targets and give an overview of the effects of EPIs on biofilm formation.
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Affiliation(s)
| | | | - Wenjuan Zhou
- Department of Implantology, Yantai Stomatological Hospital Affiliated to Binzhou Medical University, Yantai, China
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3
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Guo Z, Liu M, Zhang D. Potential of phage depolymerase for the treatment of bacterial biofilms. Virulence 2023; 14:2273567. [PMID: 37872768 PMCID: PMC10621286 DOI: 10.1080/21505594.2023.2273567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/30/2023] [Indexed: 10/25/2023] Open
Abstract
Resistance of bacteria to antibiotics is a major concern in medicine and veterinary science. The bacterial biofilm structures not only prevent the penetration of drugs into cells within the biofilm's interior but also aid in evasion of the host immune system. Hence, there is an urgent need to develop novel therapeutic approaches against bacterial biofilms. One potential strategy to counter biofilms is to use phage depolymerases that degrade the matrix structure of the bacteria and enable access to bacterial cells. This review mainly discusses the methods by which phage depolymerases enhance the efficacy of the human immune system and the therapeutic applications of some phage depolymerases, such as single phage depolymerase application, combined therapy with phage depolymerase and antibiotics, and phage depolymerase cocktails, for treating bacterial biofilms. This review also summarizes the relationship between bacterial biofilms and antibiotic resistance.
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Affiliation(s)
- Zhimin Guo
- Department of Laboratory Medicine, Infectious Diseases and Pathogen Biology Center, The First Hospital of Jilin University, Changchun, China
| | - Mengmeng Liu
- Department of Laboratory Medicine, The First Hospital of Jilin University, Changchun, China
| | - Dan Zhang
- Department of Hepatological Surgery, The First Hospital of Jilin University, Changchun, China
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4
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Li Y, Ni M. Regulation of biofilm formation in Klebsiella pneumoniae. Front Microbiol 2023; 14:1238482. [PMID: 37744914 PMCID: PMC10513181 DOI: 10.3389/fmicb.2023.1238482] [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] [Received: 06/11/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023] Open
Abstract
Klebsiella pneumoniae is an important Gram-negative opportunistic pathogen that is responsible for a variety of nosocomial and community-acquired infections. Klebsiella pneumoniae has become a major public health issue owing to the rapid global spread of extensively-drug resistant (XDR) and hypervirulent strains. Biofilm formation is an important virulence trait of K. pneumoniae. A biofilm is an aggregate of microorganisms attached to an inert or living surface by a self-produced exo-polymeric matrix that includes proteins, polysaccharides and extracellular DNA. Bacteria within the biofilm are shielded from antibiotics treatments and host immune responses, making it more difficult to eradicate K. pneumoniae-induced infection. However, the detailed mechanisms of biofilm formation in K. pneumoniae are still not clear. Here, we review the factors involved in the biofilm formation of K. pneumoniae, which might provide new clues to address this clinical challenge.
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Affiliation(s)
| | - Ming Ni
- Department and Institute of Infectious Disease, Tongji Hospital, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Disease, Huazhong University of Science and Technology, Wuhan, China
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Naidu V, Bartczak A, Brzoska AJ, Lewis P, Eijkelkamp BA, Paulsen IT, Elbourne LDH, Hassan KA. Evolution of RND efflux pumps in the development of a successful pathogen. Drug Resist Updat 2023; 66:100911. [PMID: 36592567 DOI: 10.1016/j.drup.2022.100911] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
AIMS This study examined the origins and evolution of the AdeABC, AdeFGH and AdeIJK efflux pumps in the Acinetobacter genus, including human and animal pathogens and species from non-clinical environments. METHODS Comparative genome analyses were performed using the reference sequences for 70 Acinetobacter species to identify putative orthologs of AdeABC, AdeFGH and AdeIJK and their regulators. Sequence similarities and the genomic locations of coding sequences were correlated with phylogeny to infer modes of evolution. Intraspecies variation was assessed in species of interest using up to 236 complete genome sequences. Mutants overproducing adeIJK in A. baylyi were examined to identify regulators of this system in a non A. baumannii species. RESULTS The results indicate that adeIJK has been a stable part of Acinetobacter genomes since the genesis of this genus, whereas adeABC and adeFGH were carried by less than half of the species, but showed some lineage specificity. The organisation and local genetic contexts of adeABC loci were particularly variable to the sub-species level, suggesting frequent recombination. Cognate regulatory systems were almost always found in the genomes of species encoding pumps. Mutations in adeN, which encodes a repressor of adeIJK, were selected by antibiotic exposure in A. baylyi, similar to previous findings in pathogenic lineages. CONCLUSIONS The multidrug efflux capacity of clinical Acinetobacter strains stems from accessory and core genetic features. AdeIJK is likely to have ancient core function(s) that have promoted its maintenance, whereas recent antibiotic use may be driving the evolution of the AdeABC pump.
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Affiliation(s)
- Varsha Naidu
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW, Australia; ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, NSW, Australia
| | - Amelia Bartczak
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Anthony J Brzoska
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW, Australia
| | - Peter Lewis
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia; Hunter Biological Solutions, Newcastle, NSW, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Ian T Paulsen
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, NSW, Australia; School of Natural Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Liam D H Elbourne
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, NSW, Australia; School of Natural Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Karl A Hassan
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW, Australia; ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, NSW, Australia.
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Discovery of Two Inhibitors of the Type IV Pilus Assembly ATPase PilB as Potential Antivirulence Compounds. Microbiol Spectr 2022; 10:e0387722. [PMID: 36377931 PMCID: PMC9769694 DOI: 10.1128/spectrum.03877-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
With the pressing antibiotic resistance pandemic, antivirulence has been increasingly explored as an alternative strategy against bacterial infections. The bacterial type IV pilus (T4P) is a well-documented virulence factor and an attractive target for small molecules for antivirulence purposes. The PilB ATPase is essential for T4P biogenesis because it catalyzes the assembly of monomeric pilins into the polymeric pilus filament. Here, we describe the identification of two PilB inhibitors by a high-throughput screen (HTS) in vitro and their validation as effective inhibitors of T4P assembly in vivo. We used Chloracidobacterium thermophilum PilB as a model enzyme to optimize an ATPase assay for the HTS. From a library of 2,320 compounds, benserazide and levodopa, two approved drugs for Parkinson's disease, were identified and confirmed biochemically to be PilB inhibitors. We demonstrate that both compounds inhibited the T4P-dependent motility of the bacteria Myxoccocus xanthus and Acinetobacter nosocomialis. Additionally, benserazide and levodopa were shown to inhibit A. nosocomialis biofilm formation, a T4P-dependent process. Using M. xanthus as a model, we showed that both compounds inhibited T4P assembly in a dose-dependent manner. These results suggest that these two compounds are effective against the PilB protein in vivo. The potency of benserazide and levodopa as PilB inhibitors both in vitro and in vivo demonstrate potentials of the HTS and its two hits here for the development of anti-T4P chemotherapeutics. IMPORTANCE Many bacterial pathogens use their type IV pilus (T4P) to facilitate and maintain an infection in a human host. Small-molecule inhibitors of the production or assembly of the T4P are promising for the treatment and prevention of infections by these bacteria, especially in our fight against antibiotic-resistant pathogens. Here, we report the development and implementation of a method to identify anti-T4P chemicals from compound libraries by high-throughput screen. This led to the identification and validation of two T4P inhibitors both in the test tubes and in bacteria. The discovery and validation pipeline reported here as well as the confirmation of two anti-T4P inhibitors provide new venues and leads for the development of chemotherapeutics against antibiotic-resistant infections.
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Chai WC, Whittall JJ, Polyak SW, Foo K, Li X, Dutschke CJ, Ogunniyi AD, Ma S, Sykes MJ, Semple SJ, Venter H. Cinnamaldehyde derivatives act as antimicrobial agents against Acinetobacter baumannii through the inhibition of cell division. Front Microbiol 2022; 13:967949. [PMID: 36106080 PMCID: PMC9465178 DOI: 10.3389/fmicb.2022.967949] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell division protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents. We have previously reported limited activity of cinnamaldehyde analogs against Escherichia coli. In this study, we have determined the antimicrobial activity of six cinnamaldehyde analogs for antimicrobial activity against A. baumannii. Microscopic analysis was performed to determine if the compounds inhibit cell division. The on-target effect of the compounds was assessed by analyzing their effect on polymerization and on the GTPase activity of purified FtsZ from A. baumannii. In silico docking was used to assess the binding of cinnamaldehyde analogs. Finally, in vivo and in vitro safety assays were performed. All six compounds displayed antibacterial activity against the critical priority pathogen A. baumannii, with 4-bromophenyl-substituted 4 displaying the most potent antimicrobial activity (MIC 32 μg/mL). Bioactivity was significantly increased in the presence of an efflux pump inhibitor for A. baumannii ATCC 19606 (up to 32-fold) and significantly, for extensively drug resistant UW 5075 (greater than 4-fold), suggesting that efflux contributes to the intrinsic resistance of A. baumannii against these agents. The compounds inhibited cell division in A. baumannii as observed by the elongated phenotype and targeted the FtsZ protein as seen from the inhibition of polymerization and GTPase activity. In silico docking predicted that the compounds bind in the interdomain cleft adjacent to the H7 core helix. Di-chlorinated 6 was devoid of hemolytic activity and cytotoxicity against mammalian cells in vitro, as well as adverse activity in a Caenorhabditis elegans nematode model in vivo. Together, these findings present halogenated analogs 4 and 6 as promising candidates for further development as antimicrobial agents aimed at combating A. baumannii. This is also the first report of FtsZ-targeting compounds with activity against an XDR A. baumannii strain.
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Affiliation(s)
- Wern Chern Chai
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Jonathan J. Whittall
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Steven W. Polyak
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Klyie Foo
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Xin Li
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Cameron J. Dutschke
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Abiodun D. Ogunniyi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Matthew J. Sykes
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Susan J. Semple
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
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Liu PX, Zhang XY, Wang Q, Li YY, Sun WD, Qi Y, Zhou K, Han XG, Chen ZG, Fang WH, Jiang W. Biological and transcriptional studies reveal VmeL is involved in motility, biofilm formation and virulence in Vibrio parahaemolyticus. Front Microbiol 2022; 13:976334. [PMID: 36016795 PMCID: PMC9397117 DOI: 10.3389/fmicb.2022.976334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022] Open
Abstract
Vibrio parahaemolyticus is a marine pathogen thought to be the leading cause of seafood-borne gastroenteritis globally, urgently requiring efficient management methods. V. parahaemolyticus encodes 12 resistance/nodulation/division (RND) efflux systems. However, research on these systems is still in its infancy. In this study, we discovered that the inactivation of VmeL, a membrane fusion protein within the RND efflux systems, led to reduction of the ability of biofilm formation. Further results displayed that the decreased capacity of Congo red binding and the colony of ΔvmeL is more translucent compared with wild type strains, suggested reduced biofilm formation due to decreased production of biofilm exopolysaccharide upon vmeL deletion. In addition, the deletion of vmeL abolished surface swarming and swimming motility of V. parahaemolyticus. Additionally, deletion of vmeL weakened the cytotoxicity of V. parahaemolyticus towards HeLa cells, and impaired its virulence in a murine intraperitoneal infection assay. Finally, through RNA-sequencing, we ascertained that there were 716 upregulated genes and 247 downregulated genes in ΔvmeL strain. KEGG enrichment analysis revealed that quorum sensing, bacterial secretion systems, ATP-binding cassette transporters, and various amino acid metabolism pathways were altered due to the inactivation of vmeL. qRT-PCR further confirmed that genes accountable to the type III secretion system (T3SS1) and lateral flagella were negatively affected by vmeL deletion. Taken together, our results suggest that VmeL plays an important role in pathogenicity, making it a good target for managing infection with V. parahaemolyticus.
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Affiliation(s)
- Peng-xuan Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiao-yun Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Quan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Yang-yang Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Wei-dong Sun
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yu Qi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Kai Zhou
- Shenzhen Institute of Respiratory Diseases, The First Affiliated Hospital (Shenzhen People’s Hospital), Shenzhen, China
| | - Xian-gan Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Zhao-guo Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Wei-huan Fang
- Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, China
| | - Wei Jiang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
- *Correspondence: Wei Jiang,
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Abatedaga I, Perez Mora B, Tuttobene M, Müller G, Biancotti D, Borsarelli CD, Valle L, Mussi MA. Characterization of BLUF-photoreceptors present in Acinetobacter nosocomialis. PLoS One 2022; 17:e0254291. [PMID: 35442978 PMCID: PMC9020721 DOI: 10.1371/journal.pone.0254291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 03/01/2022] [Indexed: 11/18/2022] Open
Abstract
Acinetobacter nosocomialis is a Gram-negative opportunistic pathogen, whose ability to cause disease in humans is well recognized. Blue light has been shown to modulate important physiological traits related to persistence and virulence in this microorganism. In this work, we characterized the three Blue Light sensing Using FAD (BLUF) domain-containing proteins encoded in the A. nosocomialis genome, which account for the only canonical light sensors present in this microorganism. By focusing on a light-modulated bacterial process such as motility, the temperature dependence of light regulation was studied, as well as the expression pattern and spectroscopic characteristics of the different A. nosocomialis BLUFs. Our results show that the BLUF-containing proteins AnBLUF65 and AnBLUF46 encode active photoreceptors in the light-regulatory temperature range when expressed recombinantly. In fact, AnBLUF65 is an active photoreceptor in the temperature range from 15°C to 37°C, while AnBLUF46 between 15°C to 32°C, in vitro. In vivo, only the Acinetobacter baumannii BlsA’s ortholog AnBLUF65 was expressed in A. nosocomialis cells recovered from motility plates. Moreover, complementation assays showed that AnBLUF65 is able to mediate light regulation of motility in A. baumannii ΔblsA strain at 30°C, confirming its role as photoreceptor and in modulation of motility by light. Intra-protein interactions analyzed using 3D models built based on A. baumannii´s BlsA photoreceptor, show that hydrophobic/aromatic intra-protein interactions may contribute to the stability of dark/light- adapted states of the studied proteins, reinforcing the previous notion on the importance of these interactions in BLUF photoreceptors. Overall, the results presented here reveal the presence of BLUF photoreceptors in A. nosocomialis with idiosyncratic characteristics respect to the previously characterized A. baumannii’s BlsA, both regarding the photoactivity temperature-dependency as well as expression patterns, contributing thus to broaden our knowledge on the BLUF family.
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Affiliation(s)
- Inés Abatedaga
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
| | - Bárbara Perez Mora
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Marisel Tuttobene
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Gabriela Müller
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Daiana Biancotti
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Claudio D. Borsarelli
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
- Instituto de Ciencias Químicas (ICQ), Facultad de Agronomía y Agroindustrias (FAyA), UNSE, Santiago del Estero, Argentina
| | - Lorena Valle
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
- Instituto de Ciencias Químicas (ICQ), Facultad de Agronomía y Agroindustrias (FAyA), UNSE, Santiago del Estero, Argentina
- * E-mail: (MAM); (LV)
| | - Maria A. Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
- * E-mail: (MAM); (LV)
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Hinkel LA, Willsey GG, Lenahan SM, Eckstrom K, Schutz KC, Wargo MJ. Creatine utilization as a sole nitrogen source in Pseudomonas putida KT2440 is transcriptionally regulated by CahR. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35266867 DOI: 10.1099/mic.0.001145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Glutamine amidotransferase-1 domain-containing AraC-family transcriptional regulators (GATRs) are present in the genomes of many bacteria, including all Pseudomonas species. The involvement of several characterized GATRs in amine-containing compound metabolism has been determined, but the full scope of GATR ligands and regulatory networks are still unknown. Here, we characterize Pseudomonas putida's detection of the animal-derived amine compound creatine, a compound particularly enriched in muscle and ciliated cells by a creatine-specific GATR, PP_3665, here named CahR (Creatine amidohydrolase Regulator). cahR is necessary for transcription of the gene encoding creatinase (PP_3667/creA) in the presence of creatine and is critical for P. putida's ability to utilize creatine as a sole source of nitrogen. The CahR/creatine regulon is small, and an electrophoretic mobility shift assay demonstrates strong and specific CahR binding only at the creA promoter, supporting the conclusion that much of the regulon is dependent on downstream metabolites. Phylogenetic analysis of creA orthologues associated with cahR orthologues highlights a strain distribution and organization supporting probable horizontal gene transfer, particularly evident within the genus Acinetobacter. This study identifies and characterizes the GATR that transcriptionally controls P. putida's metabolism of creatine, broadening the scope of known GATR ligands and suggesting GATR diversification during evolution of metabolism for aliphatic nitrogen compounds.
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Affiliation(s)
- Lauren A Hinkel
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405, USA
- Present address: Department of Biology, Rutgers Camden, Camden, NJ 08182, USA
| | - Graham G Willsey
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405, USA
- Present address: Division of Infectious Diseases, Department of Health, Wadsworth Center, New York State, Albany, NY 12208, USA
| | - Sean M Lenahan
- Cellular, Molecular and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT 05405, USA
| | - Korin Eckstrom
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA
| | - Kristin C Schutz
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA
| | - Matthew J Wargo
- Department of Microbiology and Molecular Genetics, University of Vermont Larner College of Medicine, Burlington, VT 05405, USA
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11
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Bocatti CR, Ferreira E, Ribeiro RA, de Oliveira Chueire LM, Delamuta JRM, Kobayashi RKT, Hungria M, Nogueira MA. Microbiological quality analysis of inoculants based on Bradyrhizobium spp. and Azospirillum brasilense produced "on farm" reveals high contamination with non-target microorganisms. Braz J Microbiol 2022; 53:267-280. [PMID: 34984661 PMCID: PMC8882540 DOI: 10.1007/s42770-021-00649-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 11/01/2021] [Indexed: 11/24/2022] Open
Abstract
The use of inoculants carrying diazotrophic and other plant growth-promoting bacteria plays an essential role in the Brazilian agriculture, with a growing use of microorganism-based bioproducts. However, in the last few years, some farmers have multiplied microorganisms in the farm, known as "on farm" production, including inoculants of Bradyrhizobium spp. for soybean (Glycine max L. Merrill.) and Azospirillum brasilense for corn (Zea mays L.) or co-inoculation in soybean. The objective was to assess the microbiological quality of such inoculants concerning the target microorganisms and contaminants. In the laboratory, 18 samples taken in five states were serial diluted and spread on culture media for obtaining pure and morphologically distinct colonies of bacteria, totaling 85 isolates. Molecular analysis based on partial sequencing of the 16S rRNA gene revealed 25 genera of which 44% harbor species potentially pathogenic to humans; only one of the isolates was identified as Azospirillum brasilense, whereas no isolate was identified as Bradyrhizobium. Among 34 isolates belonging to genera harboring species potentially pathogenic to humans, 12 had no resistance to antibiotics, six presented intrinsic resistance, and 18 presented non-intrinsic resistance to at least one antibiotic. One of the samples analyzed with a shotgun-based metagenomics approach to check for the microbial diversity showed several genera of microorganisms, mainly Acetobacter (~ 32% of sequences) but not the target microorganism. The samples of inoculants produced on farm were highly contaminated with non-target microorganisms, some of them carrying multiple resistances to antibiotics.
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Affiliation(s)
- Camila Rafaeli Bocatti
- Department of Microbiology, Universidade Estadual de Londrina, C. Postal 10.011, Londrina, PR, 86057-970, Brazil
| | - Eduara Ferreira
- Embrapa Soja, C. Postal 4006, Londrina, PR, 86081-981, Brazil
| | - Renan Augusto Ribeiro
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brasília, DF, Brazil
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12
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Abstract
The bacterial pathogen Acinetobacter baumannii has emerged as an urgent threat to health care systems. The prevalence of multidrug resistance in this critical human pathogen is closely associated with difficulties in its eradication from the hospital environment and its recalcitrance to treatment during infection. The development of resistance in A. baumannii is in part due to substantial plasticity of its genome, facilitating spontaneous genomic evolution. Many studies have investigated selective pressures imposed by antibiotics on genomic evolution, but the influence of high-abundance bioactive molecules at the host-pathogen interface on mutation and rates of evolution is poorly understood. Here, we studied the roles of host fatty acids in the gain in resistance to common antibiotics. We defined the impact of the polyunsaturated fatty acids arachidonic acid and docosahexaenoic acid on the development of resistance to erythromycin in A. baumannii strain AB5075_UW using a microevolutionary approach. We employed whole-genome sequencing and various phenotypic analyses to characterize microbe-lipid-antibiotic interactions. Cells exposed to erythromycin in the presence of the fatty acids displayed significantly lower rates of development of resistance to erythromycin and, importantly, tetracycline. Subsequent analyses defined diverse means by which host fatty acids influence the mutation rates. This work has highlighted the critical need to consider the roles of host fatty acids in A. baumannii physiology and antimicrobial resistance. Collectively, we have identified a novel means to curb the development of resistance in this critical human pathogen. IMPORTANCE The global distribution of multidrug resistance in A. baumannii has necessitated seeking not only alternative therapeutic approaches but also the means to limit the development of resistance in clinical settings. Highly abundant host bioactive compounds, such as polyunsaturated fatty acids, are readily acquired by A. baumannii during infection and have been illustrated to impact the bacterium's membrane composition and antibiotic resistance. In this work, we show that in vitro supplementation with host polyunsaturated fatty acids reduces the rate at which A. baumannii gains resistance to erythromycin and tetracycline. Furthermore, we discover that the impact on resistance development is closely associated with the primary antimicrobial efflux systems of A. baumannii, which represent one of the major drivers of clinical resistance. Overall, this study emphasizes the potential of host macromolecules in novel approaches to circumvent the difficulties of multidrug resistance during A. baumannii treatment, with fatty acid supplements such as fish oil providing safe and cost-effective ways to enhance host tolerance to bacterial infections.
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13
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Corral J, Pérez-Varela M, Sánchez-Osuna M, Cortés P, Barbé J, Aranda J. Importance of twitching and surface-associated motility in the virulence of Acinetobacter baumannii. Virulence 2021; 12:2201-2213. [PMID: 34515614 PMCID: PMC8451467 DOI: 10.1080/21505594.2021.1950268] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Acinetobacter baumannii is a pathogen of increasing clinical importance worldwide, especially given its ability to readily acquire resistance determinants. Motile strains of this bacterium can move by either or both of two types of motility: (i) twitching, driven by type IV pili, and (ii) surface-associated motility, an appendage-independent form of movement. A. baumannii strain MAR002 possesses both twitching and surface-associated motility. In this study, we isolated spontaneous rifampin-resistant mutants of strain MAR002 in which point mutations in the rpoB gene were identified that resulted in an altered motility pattern. Transcriptomic analysis of mutants lacking twitching, surface-associated motility, or both led to the identification of deregulated genes within each motility phenotype, based on their level of expression and their biological function. Investigations of the corresponding knockout mutants revealed several genes involved in the motility of A. baumannii strain MAR002, including two involved in twitching (encoding a minor pilin subunit and an RND [resistance nodulation division] component), one in surface-associated motility (encoding an amino acid permease), and eight in both (encoding RND and ABC components, the energy transducer TonB, the porin OprD, the T6SS component TagF, an IclR transcriptional regulator, a PQQ-dependent sugar dehydrogenase, and a putative pectate lyase). Virulence assays showed the reduced pathogenicity of mutants with impairments in both types of motility or in surface-associated motility alone. By contrast, the virulence of twitching-affected mutants was not affected. These results shed light on the key role of surface-associated motility and the limited role of twitching in the pathogenicity of A. baumannii.
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Affiliation(s)
- Jordi Corral
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - María Pérez-Varela
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Miquel Sánchez-Osuna
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Pilar Cortés
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Jordi Barbé
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Jesús Aranda
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
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14
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Adewoyin MA, Ebomah KE, Okoh AI. Antibiogram Profile of Acinetobacterbaumannii Recovered from Selected Freshwater Resources in the Eastern Cape Province, South Africa. Pathogens 2021; 10:pathogens10091110. [PMID: 34578143 PMCID: PMC8466806 DOI: 10.3390/pathogens10091110] [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] [Received: 05/11/2021] [Revised: 07/04/2021] [Accepted: 07/16/2021] [Indexed: 11/25/2022] Open
Abstract
Acinetobacter species have been found in a variety of environments, including soil, food, plants, hospital environments and water. Acinetobacter baumannii is an opportunistic and emerging waterborne pathogen. It has been implicated in several nosocomial infections that demonstrate resistance to commonly administered antibiotics. We investigated phenotypic antibiotic resistance (PAR) and relevant antibiotic resistance genes (ARGs) in A. baumannii isolated from three freshwater resources in the Eastern Cape Province, South Africa; A. baumannii (410) was confirmed by the recA and gyrB genes of 844 suspected Acinetobacter species in the water samples. The PAR of the confirmed isolates was assessed using a panel of 11 antibiotics by the disc diffusion method, while ARGs were investigated in isolates exhibiting PAR. The A. baumannii isolates were resistant to piperacillin-tazobactam (11.2%), ceftazidime (12%), cefotaxime (18.8%), cefepime (8.8%), imipenem (2.7%), meropenem (4.15%), amikacin (2.4%), gentamicin (8.8%), tetracycline (16.8%), ciprofloxacin (11%) and trimethoprim/sulfamethoxazole (20.5%). For multidrug resistance (MDR), two isolates were resistant to all antibiotics and 28 isolates were resistant to imipenem and meropenem. Moreover, β-lactamases blaTEM (64.4%) and blaOXA-51 (28.70%) as well as sulphonamides sul1 (37.1%) and sul2 (49.4%) were common ARGs. Overall, PAR and ARGs had positive correlations (r) in all rivers. Detection of MDR-A. baumannii in freshwater resources could be linked to possible wastewater discharge from the nearby animal farms, indicating potential implications for public health.
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Affiliation(s)
- Mary Ayobami Adewoyin
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, South Africa; (K.E.E.); (A.I.O.)
- Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa
- Correspondence: ; Tel.: +27-730-809-512
| | - Kingsley Ehi Ebomah
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, South Africa; (K.E.E.); (A.I.O.)
- Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa
| | - Anthony Ifeanyi Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, South Africa; (K.E.E.); (A.I.O.)
- Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa
- Department of Environmental Health Sciences, College of Health Sciences, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates
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15
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Sanz-García F, Gil-Gil T, Laborda P, Ochoa-Sánchez LE, Martínez JL, Hernando-Amado S. Coming from the Wild: Multidrug Resistant Opportunistic Pathogens Presenting a Primary, Not Human-Linked, Environmental Habitat. Int J Mol Sci 2021; 22:8080. [PMID: 34360847 PMCID: PMC8347278 DOI: 10.3390/ijms22158080] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/24/2022] Open
Abstract
The use and misuse of antibiotics have made antibiotic-resistant bacteria widespread nowadays, constituting one of the most relevant challenges for human health at present. Among these bacteria, opportunistic pathogens with an environmental, non-clinical, primary habitat stand as an increasing matter of concern at hospitals. These organisms usually present low susceptibility to antibiotics currently used for therapy. They are also proficient in acquiring increased resistance levels, a situation that limits the therapeutic options for treating the infections they cause. In this article, we analyse the most predominant opportunistic pathogens with an environmental origin, focusing on the mechanisms of antibiotic resistance they present. Further, we discuss the functions, beyond antibiotic resistance, that these determinants may have in the natural ecosystems that these bacteria usually colonize. Given the capacity of these organisms for colonizing different habitats, from clinical settings to natural environments, and for infecting different hosts, from plants to humans, deciphering their population structure, their mechanisms of resistance and the role that these mechanisms may play in natural ecosystems is of relevance for understanding the dissemination of antibiotic resistance under a One-Health point of view.
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Affiliation(s)
| | | | | | | | - José L. Martínez
- Centro Nacional de Biotecnología, CSIC, 28049 Madrid, Spain; (F.S.-G.); (T.G.-G.); (P.L.); (L.E.O.-S.); (S.H.-A.)
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16
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Çimen M, Düzgün AÖ. Antibiotic induced biofilm formation of novel multidrug resistant Acinetobacter baumannii ST2121 clone. Acta Microbiol Immunol Hung 2021; 68:80-86. [PMID: 33180031 DOI: 10.1556/030.2020.01240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/01/2020] [Indexed: 12/14/2022]
Abstract
The aim of this study was to identify antimicrobial resistance and virulence factor genes exhibited by multidrug resistant (MDR) Acinetobacter baumannii, to analyze biofilm formation and to investigate clonal subtypes of isolate. Whole genome sequencing was done by Illumina NovaSeq 6,000 platform and multilocus sequence typing (MLST) was performed by Oxford and Pasteur typing schemes. Influence of imipenem and levofloxacin on biofilm formation was investigated in 96-well plates at 3 replicates. The strain was found to carry OXA-23, OXA-51-like, AmpC and TEM-1 beta-lactamases. The sequence of the blaOXA-51-like gene has been identified as a blaOXA-66. According to Pasteur MLST scheme the strain displayed ST2 allelic profile. However, based on Oxford MLST scheme this strain represents the new ST2121, as the gdhB gene has a single allelic mutation namely, the gdhB-227. It was determined that MDR isolate carried bap, basABCDFGHIJ, csuA/BABCDE, bauABCDEF, plcD, pgaABCD, entE, barAB, ompA, abaIR, piT2EAFTE/AUBl, fimADT, cvaC, bfmR, bfmS virulence genes. In our study imipenem induced the highest biofilm formation at a concentration of 32 µg/ml and levofloxacin at a concentration of 16 µg/ml. In conclusion, we detected a new MDR A. baumannii ST2121 clone harboring blaOXA-66 gene that has been reported for the first time in Turkey.
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Affiliation(s)
- Müberra Çimen
- 1Department of Biotechnology, Institute of Natural Sciences, Gumushane University, Gümüşhane, Turkey
| | - Azer Özad Düzgün
- 2Department of Genetics and Bioengineering, Faculty of Engineering and Natural Sciences, Gumushane University, Gümüşhane, Turkey
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17
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Cabral BG, Brasiliense DM, Furlaneto IP, Rodrigues YC, Lima KVB. Surgical Site Infection Following Caesarean Section by Acinetobacter Species: A Report from a Hyperendemic Setting in the Brazilian Amazon Region. Microorganisms 2021; 9:microorganisms9040743. [PMID: 33918140 PMCID: PMC8067217 DOI: 10.3390/microorganisms9040743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 12/31/2022] Open
Abstract
Surgical site infection (SSI) following caesarean section is associated with increased morbidity, mortality, and significant health care costs. This study evaluated the epidemiological, clinical, and microbiological features of Acinetobacter spp. in women with SSIs who have undergone caesarean section at a referral hospital in the Brazilian Amazon region. This study included 69 women with post-caesarean SSI by Acinetobacter spp. admitted to the hospital between January 2012 and May 2015. The 69 Acinetobacter isolates were subjected to molecular species identification, antimicrobial susceptibility testing, detection of carbapenemase-encoding genes, and genotyping. The main complications of post-caesarean SSI by Acinetobacter were inadequate and prolonged antibiotic therapy, sepsis, prolonged hospitalization, and re-suture procedures. A. baumannii, A. nosocomialis and A. colistiniresistens species were identified among the isolates. Carbapenem resistance was associated with OXA-23-producing A. baumannii isolates and IMP-1-producing A. nosocomialis isolate. Patients with multidrug-resistant A. baumannii infection showed worse clinical courses. Dissemination of persistent epidemic clones was observed, and the main clonal complexes (CC) for A. baumannii were CC231 and CC236 (Oxford scheme) and CC1 and CC15 (Pasteur scheme). This is the first report of a long-term Acinetobacter spp. outbreak in women who underwent caesarean section at a Brazilian hospital. This study demonstrates the impact of multidrug resistance on the clinical course of post-caesarean infections.
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Affiliation(s)
- Blenda Gonçalves Cabral
- Parasitic Biology in the Amazon Region, Center of Biological and Health Sciences, State University of Pará, Belém 66087-662, PA, Brazil; (B.G.C.); (Y.C.R.); (K.V.B.L.)
| | - Danielle Murici Brasiliense
- Bacteriology and Mycology Section, Evandro Chagas Institute, Ananindeua 67030-000, PA, Brazil
- Correspondence: ; Tel.: +55-9132-1421-16
| | | | - Yan Corrêa Rodrigues
- Parasitic Biology in the Amazon Region, Center of Biological and Health Sciences, State University of Pará, Belém 66087-662, PA, Brazil; (B.G.C.); (Y.C.R.); (K.V.B.L.)
| | - Karla Valéria Batista Lima
- Parasitic Biology in the Amazon Region, Center of Biological and Health Sciences, State University of Pará, Belém 66087-662, PA, Brazil; (B.G.C.); (Y.C.R.); (K.V.B.L.)
- Bacteriology and Mycology Section, Evandro Chagas Institute, Ananindeua 67030-000, PA, Brazil
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18
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Chen L, Tan P, Zeng J, Yu X, Cai Y, Liao K, Guo P, Chen Y, Wu Z, Qu P, Cai R, Chen C, Huang B. Impact of an Intervention to Control Imipenem-Resistant Acinetobacter baumannii and Its Resistance Mechanisms: An 8-Year Survey. Front Microbiol 2021; 11:610109. [PMID: 33664711 PMCID: PMC7921317 DOI: 10.3389/fmicb.2020.610109] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/24/2020] [Indexed: 01/09/2023] Open
Abstract
Background This study aimed to examine the impact of an intervention carried out in 2011 to combat multi-drug resistance and outbreaks of imipenem-resistant Acinetobacter baumannii (IRAB), and to explore its resistance mechanism. Methods A total of 2572 isolates of A. baumannii, including 1673 IRAB isolates, were collected between 2007 and 2014. An intervention was implemented to control A. baumannii resistance and outbreaks. Antimicrobial susceptibility was tested by calculating minimal inhibitory concentrations (MICs), and outbreaks were typed using pulsed-field gel electrophoresis (PFGE). Resistance mechanisms were explored by polymerase chain reaction (PCR) and whole genome sequencing (WGS). Results Following the intervention in 2011, the resistance rates of A. baumannii to almost all tested antibiotics decreased, from 85.3 to 72.6% for imipenem, 100 to 80.8% for ceftriaxone, and 45.0 to 6.9% for tigecycline. The intervention resulted in a decrease in the number (seven to five), duration (8–3 months), and departments (five to three) affected by outbreaks; no outbreaks occurred in 2011. After the intervention, only blaAMPC (76.47 to 100%) and blaTEM–1 (75.74 to 96.92%) increased (P < 0.0001); whereas blaGES–1 (32.35 to 3.07%), blaPER–1 (21.32 to 1.54%), blaOXA–58 (60.29 to 1.54%), carO (37.50 to 7.69%), and adeB (9.56 to 3.08%) decreased (P < 0.0001). Interestingly, the frequency of class B β-lactamase genes decreased from 91.18% (blaSPM–1) and 61.03% (blaIMP–1) to 0%, while that of class D blaOXA–23 increased to 96.92% (P < 0.0001). WGS showed that the major PFGE types causing outbreaks each year (type 01, 11, 18, 23, 26, and 31) carried the same resistance genes (blaKPC–1, blaADC–25, blaOXA–66, and adeABC), AdeR-S mutations (G186V and A136V), and a partially blocked porin channel CarO. Meanwhile, plasmids harboring blaOXA–23 were found after the intervention. Conclusion The intervention was highly effective in reducing multi-drug resistance of A. baumannii and IRAB outbreaks in the long term. The resistance mechanisms of IRAB may involve genes encoding β-lactamases, efflux pump overexpression, outer membrane porin blockade, and plasmids; in particular, clonal spread of blaOXA–23 was the major cause of outbreaks. Similar interventions may also help reduce bacterial resistance rates and outbreaks in other hospitals.
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Affiliation(s)
- Lida Chen
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Blood Transfusion, China-Japan Friendship Hospital, Beijing, China
| | - Pinghai Tan
- Department of Hematology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jianming Zeng
- Department of Laboratory Medicine, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Xuegao Yu
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yimei Cai
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Kang Liao
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Penghao Guo
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yili Chen
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zongwen Wu
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Pinghua Qu
- Department of Laboratory Medicine, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Renxin Cai
- Department of Laboratory Medicine, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Cha Chen
- Department of Laboratory Medicine, The Second Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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19
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Boyce JH, Dang B, Ary B, Edmondson Q, Craik CS, DeGrado WF, Seiple IB. Platform to Discover Protease-Activated Antibiotics and Application to Siderophore-Antibiotic Conjugates. J Am Chem Soc 2020; 142:21310-21321. [PMID: 33301681 DOI: 10.1021/jacs.0c06987] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Here we present a platform for discovery of protease-activated prodrugs and apply it to antibiotics that target Gram-negative bacteria. Because cleavable linkers for prodrugs had not been developed for bacterial proteases, we used substrate phage to discover substrates for proteases found in the bacterial periplasm. Rather than focusing on a single protease, we used a periplasmic extract of E. coli to find sequences with the greatest susceptibility to the endogenous mixture of periplasmic proteases. Using a fluorescence assay, candidate sequences were evaluated to identify substrates that release native amine-containing payloads. We next designed conjugates consisting of (1) an N-terminal siderophore to facilitate uptake, (2) a protease-cleavable linker, and (3) an amine-containing antibiotic. Using this strategy, we converted daptomycin-which by itself is active only against Gram-positive bacteria-into an antibiotic capable of targeting Gram-negative Acinetobacter species. We similarly demonstrated siderophore-facilitated delivery of oxazolidinone and macrolide antibiotics into a number of Gram-negative species. These results illustrate this platform's utility for development of protease-activated prodrugs, including Trojan horse antibiotics.
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Affiliation(s)
- Jonathan H Boyce
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States.,Cardiovascular Research Institute, University of California, San Francisco, California 94158, United States
| | - Bobo Dang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China.,Center for Infectious Disease Research, Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Beatrice Ary
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Quinn Edmondson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - William F DeGrado
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States.,Cardiovascular Research Institute, University of California, San Francisco, California 94158, United States
| | - Ian B Seiple
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States.,Cardiovascular Research Institute, University of California, San Francisco, California 94158, United States
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20
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Srinivasan VB, Rajamohan G. Protein phosphorylation mechanisms: a novel paradigm of antimicrobial resistance in 'critical threat' pathogens. Future Microbiol 2020; 15:837-840. [PMID: 32657616 DOI: 10.2217/fmb-2020-0009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Vijaya Bharathi Srinivasan
- Council of Scientific & Industrial Research- Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Govindan Rajamohan
- Council of Scientific & Industrial Research- Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
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21
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Holden ER, Webber MA. MarA, RamA, and SoxS as Mediators of the Stress Response: Survival at a Cost. Front Microbiol 2020. [PMID: 32431683 DOI: 10.3389/fmicb.2020.0082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
To survive and adapt to changing environments, bacteria have evolved mechanisms to express appropriate genes at appropriate times. Exposure to antimicrobials triggers a global stress response in Enterobacteriaceae, underpinned by activation of a family of transcriptional regulators, including MarA, RamA, and SoxS. These control a program of altered gene expression allowing a rapid and measured response to improve fitness in the presence of toxic drugs. Increased expression of marA, ramA, and soxS up regulates efflux activity to allow detoxification of the cell. However, this also results in trade-offs in other phenotypes, such as impaired growth rates, biofilm formation and virulence. Here, we review the current knowledge regarding the trade-offs that exist between drug survival and other phenotypes that result from induction of marA, ramA, and soxS. Additionally, we present some new findings linking expression of these regulators and biofilm formation in Enterobacteriaceae, thereby demonstrating the interconnected nature of regulatory networks within the cell and explaining how trade-offs can exist between important phenotypes. This has important implications for our understanding of how bacterial virulence and biofilms can be influenced by exposure to antimicrobials.
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Affiliation(s)
- Emma R Holden
- Quadram Institute Biosciences, Norwich, United Kingdom
| | - Mark A Webber
- Quadram Institute Biosciences, Norwich, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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22
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Holden ER, Webber MA. MarA, RamA, and SoxS as Mediators of the Stress Response: Survival at a Cost. Front Microbiol 2020; 11:828. [PMID: 32431683 PMCID: PMC7216687 DOI: 10.3389/fmicb.2020.00828] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/07/2020] [Indexed: 01/17/2023] Open
Abstract
To survive and adapt to changing environments, bacteria have evolved mechanisms to express appropriate genes at appropriate times. Exposure to antimicrobials triggers a global stress response in Enterobacteriaceae, underpinned by activation of a family of transcriptional regulators, including MarA, RamA, and SoxS. These control a program of altered gene expression allowing a rapid and measured response to improve fitness in the presence of toxic drugs. Increased expression of marA, ramA, and soxS up regulates efflux activity to allow detoxification of the cell. However, this also results in trade-offs in other phenotypes, such as impaired growth rates, biofilm formation and virulence. Here, we review the current knowledge regarding the trade-offs that exist between drug survival and other phenotypes that result from induction of marA, ramA, and soxS. Additionally, we present some new findings linking expression of these regulators and biofilm formation in Enterobacteriaceae, thereby demonstrating the interconnected nature of regulatory networks within the cell and explaining how trade-offs can exist between important phenotypes. This has important implications for our understanding of how bacterial virulence and biofilms can be influenced by exposure to antimicrobials.
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Affiliation(s)
- Emma R Holden
- Quadram Institute Biosciences, Norwich, United Kingdom
| | - Mark A Webber
- Quadram Institute Biosciences, Norwich, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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23
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Tang M, Wei X, Wan X, Ding Z, Ding Y, Liu J. The role and relationship with efflux pump of biofilm formation in Klebsiella pneumoniae. Microb Pathog 2020; 147:104244. [PMID: 32437832 DOI: 10.1016/j.micpath.2020.104244] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/04/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
This study aimed to identify the role and relationship with efflux pump of biofilm formation in Klebsiella pneumoniae. Sixty-one K. pneumoniae clinical isolates were collected between January and June of 2017 from the affiliated hospital of southwest medical university in Luzhou, China. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) were determined using broth microdilution method. Crystal violet (CV) staining and confocal laser scanning microscope (CLSM) were used to monitor biofilm formation. Efflux pump expression was investigated qualitatively and quantitatively by polymerase chain reaction (PCR) and reverse transcriptase quantitative PCR (RT-qPCR). Crystal violet staining was performed to evaluate the effect of efflux pump inhibitor carbonyl cyanide m-chlorophenyl hydrazine (CCCP) on K. pneumoniae biofilms. Our results showed that crystal violet staining and CLSM had good consistency in biofilm detection. Biofilm formation was an independent biological behavior of the strain and measured at 24 h was reasonable. Biofilms up-regulated antimicrobial resistance and expression of efflux pump gene acrA, emrB, oqxA, and qacEΔ1 in K. pneumoniae. CCCP inhibited biofilms but dose-dependent effect was obvious. Altogether, our data demonstrates that biofilm formation, as well as its interaction with efflux pump, promotes antimicrobial resistance in K. pneumoniae.
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Affiliation(s)
- Miran Tang
- Affiliated Hospital of Southwest Medical University, Luzhou City, 646000, Sichuan Province, China; Santai County People's Hospital, Mianyang City, 621100, Sichuan Province, China
| | - Xing Wei
- Pidu District People's Hospital, Chengdu City, 611730, Sichuan Province, China
| | - Xue Wan
- Affiliated Hospital of Southwest Medical University, Luzhou City, 646000, Sichuan Province, China
| | - Zixuan Ding
- Affiliated Hospital of Southwest Medical University, Luzhou City, 646000, Sichuan Province, China
| | - Yinhuan Ding
- Affiliated Hospital of Southwest Medical University, Luzhou City, 646000, Sichuan Province, China
| | - Jinbo Liu
- Affiliated Hospital of Southwest Medical University, Luzhou City, 646000, Sichuan Province, China.
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24
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Behdad R, Pargol M, Mirzaie A, Karizi SZ, Noorbazargan H, Akbarzadeh I. Efflux pump inhibitory activity of biologically synthesized silver nanoparticles against multidrug-resistant Acinetobacter baumannii
clinical isolates. J Basic Microbiol 2020; 60:494-507. [DOI: 10.1002/jobm.201900712] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/16/2020] [Accepted: 03/21/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Reyhaneh Behdad
- Department of Biology; Varamin-Pishva Branch, Islamic Azad University; Varamin Iran
| | - Minoo Pargol
- Department of Biology; Varamin-Pishva Branch, Islamic Azad University; Varamin Iran
| | - Amir Mirzaie
- Department of Biology; Roudehen Branch, Islamic Azad University; Roudehen Iran
| | - Shohreh Zare Karizi
- Department of Biology; Varamin-Pishva Branch, Islamic Azad University; Varamin Iran
| | - Hassan Noorbazargan
- Department of Biotechnology; School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences; Tehran Iran
| | - Iman Akbarzadeh
- Department of Chemical and Petrochemical Engineering; Sharif University of Technology; Tehran Iran
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25
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Complete Genome Sequence of the Nosocomial Pathogen Acinetobacter nosocomialis Strain M2. Microbiol Resour Announc 2019; 8:8/44/e00538-19. [PMID: 31672736 PMCID: PMC6953502 DOI: 10.1128/mra.00538-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter nosocomialis is an opportunistic human pathogen that is part of the Acinetobacter calcoaceticus/Acinetobacter baumannii (ACB) complex. Here, we report the complete genome sequence of Acinetobacter nosocomialis strain M2. Acinetobacter nosocomialis is an opportunistic human pathogen that is part of the Acinetobacter calcoaceticus/Acinetobacter baumannii (ACB) complex. Here, we report the complete genome sequence of Acinetobacter nosocomialis strain M2.
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26
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Roles of Efflux Pumps from Different Superfamilies in the Surface-Associated Motility and Virulence of Acinetobacter baumannii ATCC 17978. Antimicrob Agents Chemother 2019; 63:AAC.02190-18. [PMID: 30642939 DOI: 10.1128/aac.02190-18] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/07/2019] [Indexed: 02/06/2023] Open
Abstract
Although the relationship between Acinetobacter baumannii efflux pumps and antimicrobial resistance is well documented, less is known about the involvement of these proteins in the pathogenicity of this nosocomial pathogen. In previous work, we identified the AbaQ major facilitator superfamily (MFS) efflux pump and demonstrated its participation in the motility and virulence of A. baumannii In the present study, we examined the role in these processes of A. baumannii transporters belonging to different superfamilies of efflux pumps. Genes encoding known or putative permeases belonging to efflux pump superfamilies other than the MFS were selected, and the corresponding knockouts were constructed. The antimicrobial susceptibilities of these mutants were consistent with previously reported data. In mutants of A. baumannii strain ATCC 17978 carrying inactivated genes encoding the efflux pumps A1S_2736 (resistance nodulation division [RND]), A1S_3371 (multidrug and toxic compound extrusion [MATE]), and A1S_0710 (small multidrug resistance [SMR]), as well as the newly described ATP-binding cassette (ABC) permeases A1S_1242 and A1S_2622, both surface-associated motility and virulence were reduced compared to the parental strain. However, inactivation of the genes encoding the known ABC permeases A1S_0536 and A1S_1535, the newly identified putative ABC permeases A1S_0027 and A1S_1057, or the proteobacterial antimicrobial compound efflux (PACE) transporters A1S_1503 and A1S_2063 had no effects on bacterial motility or virulence. Our results demonstrate the involvement of antimicrobial transporters belonging at least to five of the six known efflux pump superfamilies in both surface-associated motility and virulence in A. baumannii ATCC 17978.
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27
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Abstract
A shift in the Western diet since the industrial revolution has resulted in a dramatic increase in the consumption of omega-6 fatty acids, with a concurrent decrease in the consumption of omega-3 fatty acids. This decrease in omega-3 fatty acid consumption has been associated with significant disease burden, including increased susceptibility to infectious diseases. Here we provide evidence that DHA, an omega-3 fatty acid, has superior antimicrobial effects upon the highly drug-resistant pathogen Acinetobacter baumannii, thereby providing insights into one of the potential health benefits of omega-3 fatty acids. The identification and characterization of two novel bacterial membrane protective mechanisms against host fatty acids provide important insights into A. baumannii adaptation during disease. Furthermore, we describe a novel role for the major multidrug efflux system AdeIJK in A. baumannii membrane maintenance and lipid transport. This core function, beyond drug efflux, increases the appeal of AdeIJK as a therapeutic target. Free fatty acids hold important immune-modulatory roles during infection. However, the host’s long-chain polyunsaturated fatty acids, not commonly found in the membranes of bacterial pathogens, also have significant broad-spectrum antibacterial potential. Of these, the omega-6 fatty acid arachidonic acid (AA) and the omega-3 fatty acid decosahexaenoic acid (DHA) are highly abundant; hence, we investigated their effects on the multidrug-resistant human pathogen Acinetobacter baumannii. Our analyses reveal that AA and DHA incorporate into the A. baumannii bacterial membrane and impact bacterial fitness and membrane integrity, with DHA having a more pronounced effect. Through transcriptional profiling and mutant analyses, we show that the A. baumannii β-oxidation pathway plays a protective role against AA and DHA, by limiting their incorporation into the phospholipids of the bacterial membrane. Furthermore, our study identified a second bacterial membrane protection system mediated by the AdeIJK efflux system, which modulates the lipid content of the membrane via direct efflux of lipids other than AA and DHA, thereby providing a novel function for this major efflux system in A. baumannii. This is the first study to examine the antimicrobial effects of host fatty acids on A. baumannii and highlights the potential of AA and DHA to protect against A. baumannii infections.
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