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Wan J, Gao X, Liu F. Regulatory role of the Cpx ESR in bacterial behaviours. Virulence 2024; 15:2404951. [PMID: 39292643 DOI: 10.1080/21505594.2024.2404951] [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: 06/04/2024] [Revised: 08/08/2024] [Accepted: 09/05/2024] [Indexed: 09/20/2024] Open
Abstract
The envelope demarcates the boundary between bacterial cell and its environment, providing a place for bacteria to transport nutrients and excrete metabolic waste, while buffering external environmental stress. Envelope stress responses (ESRs) are important tools for bacteria to sense and repair envelope damage. In this review, we discussed evidence that indicates the important role of the Cpx ESR in pathogen-host interactions, including environmental stress sensing and responses, modulation of bacterial virulence, antimicrobial resistance, and inter-kingdom signaling.
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Affiliation(s)
- Jiajia Wan
- College of Animal Sciences, Yangtze University, Jingzhou, Hubei, China
| | - Xuejun Gao
- College of Animal Sciences, Yangtze University, Jingzhou, Hubei, China
| | - Feng Liu
- College of Animal Sciences, Yangtze University, Jingzhou, Hubei, China
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2
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Zhang Y, Cai Y, Zhang B, Zhang YHPJ. Spatially structured exchange of metabolites enhances bacterial survival and resilience in biofilms. Nat Commun 2024; 15:7575. [PMID: 39217184 PMCID: PMC11366000 DOI: 10.1038/s41467-024-51940-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Abstract
Biofilm formation enhances bacterial survival and antibiotic tolerance, but the underlying mechanisms are incompletely understood. Here, we show that biofilm growth is accompanied by a reduction in bacterial energy metabolism and membrane potential, together with metabolic exchanges between the inner and outer regions in biofilms. More specifically, nutrient-starved cells in the interior supply amino acids to cells in the periphery, while peripheral cells experience a decrease in membrane potential and provide fatty acids to interior cells. Fatty acids facilitate the repair of starvation-induced membrane damage in inner cells and enhance their survival in the presence of antibiotics. Thus, metabolic exchanges between inner and outer cells contribute to survival of the nutrient-starved inner cells and contribute to antibiotic tolerance within the biofilm.
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Affiliation(s)
- Yuzhen Zhang
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, In Vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
| | - Yukmi Cai
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, In Vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Bing Zhang
- School of Information Science and Engineering, Yanshan University, Qinhuangdao, China
| | - Yi-Heng P Job Zhang
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, In Vitro Synthetic Biology Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
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3
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Calcagno A, Coppola N, Sarmati L, Tadolini M, Parrella R, Matteelli A, Riccardi N, Trezzi M, Di Biagio A, Pirriatore V, Russo A, Gualano G, Pontali E, Surace L, Falbo E, Mencarini J, Palmieri F, Gori A, Schiuma M, Lapadula G, Goletti D. Drugs for treating infections caused by non-tubercular mycobacteria: a narrative review from the study group on mycobacteria of the Italian Society of Infectious Diseases and Tropical Medicine. Infection 2024; 52:737-765. [PMID: 38329686 PMCID: PMC11142973 DOI: 10.1007/s15010-024-02183-3] [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: 10/30/2023] [Accepted: 01/12/2024] [Indexed: 02/09/2024]
Abstract
BACKGROUND Non-tuberculous mycobacteria (NTM) are generally free-living organism, widely distributed in the environment, with sporadic potential to infect. In recent years, there has been a significant increase in the global incidence of NTM-related disease, spanning across all continents and an increased mortality after the diagnosis has been reported. The decisions on whether to treat or not and which drugs to use are complex and require a multidisciplinary approach as well as patients' involvement in the decision process. METHODS AND RESULTS This review aims at describing the drugs used for treating NTM-associated diseases emphasizing the efficacy, tolerability, optimization strategies as well as possible drugs that might be used in case of intolerance or resistance. We also reviewed data on newer compounds highlighting the lack of randomised clinical trials for many drugs but also encouraging preliminary data for others. We also focused on non-pharmacological interventions that need to be adopted during care of individuals with NTM-associated diseases CONCLUSIONS: Despite insufficient efficacy and poor tolerability this review emphasizes the improvement in patients' care and the needs for future studies in the field of anti-NTM treatments.
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Affiliation(s)
- A Calcagno
- Unit of Infectious Diseases, Department of Medical Sciences, University of Turin, Turin, Italy.
- Stop TB Italy, Milan, Italy.
| | - N Coppola
- Infectious Diseases Unit, Section of Infectious Diseases, Department of Mental Health and Public Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - L Sarmati
- Department of System Medicine, Tor Vergata University and Infectious Disease Clinic, Policlinico Tor Vergata, Rome, Italy
| | - M Tadolini
- Stop TB Italy, Milan, Italy
- Infectious Diseases Unit, IRCCS Azienda Ospedaliero-Universitaria Di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - R Parrella
- Stop TB Italy, Milan, Italy
- Respiratory Infectious Diseases Unit, Cotugno Hospital, A. O. R. N. dei Colli, Naples, Italy
| | - A Matteelli
- Institute of Infectious and Tropical Diseases, WHO Collaborating Centre for TB Prevention, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - N Riccardi
- Stop TB Italy, Milan, Italy
- Infectious Diseases Unit, Department of Clinical and Experimental Medicine, Azienda Ospedaliero Universitaria Pisana, University of Pisa, Pisa, Italy
| | - M Trezzi
- Stop TB Italy, Milan, Italy
- Infectious and Tropical Diseases Unit, Department of Medical Sciences, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - A Di Biagio
- Infectious Diseases Unit, San Martino Policlinico Hospital-IRCCS for Oncology and Neurosciences, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - V Pirriatore
- Stop TB Italy, Milan, Italy
- Unit of Infectious Diseases, "DivisioneA", Ospedale Amedeo di Savoia, ASL CIttà di Torino, Turin, Italy
| | - A Russo
- Infectious Diseases Unit, Section of Infectious Diseases, Department of Mental Health and Public Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - G Gualano
- Stop TB Italy, Milan, Italy
- Respiratory Infectious Diseases Unit, National Institute for Infectious Diseases Lazzaro Spallanzani-IRCCS, Rome, Italy
| | - E Pontali
- Department of Infectious Diseases, Galliera Hospital, Genoa, Italy
| | - L Surace
- Stop TB Italy, Milan, Italy
- Dipartimento Di Prevenzione, Azienda Sanitaria Provinciale di Catanzaro, Centro di Medicina del Viaggiatore e delle Migrazioni, P. O. Giovanni Paolo II, Lamezia Terme, CZ, Italy
| | - E Falbo
- Stop TB Italy, Milan, Italy
- Dipartimento Di Prevenzione, Azienda Sanitaria Provinciale di Catanzaro, Centro di Medicina del Viaggiatore e delle Migrazioni, P. O. Giovanni Paolo II, Lamezia Terme, CZ, Italy
| | - J Mencarini
- Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy
| | - F Palmieri
- Respiratory Infectious Diseases Unit, National Institute for Infectious Diseases Lazzaro Spallanzani-IRCCS, Rome, Italy
| | - A Gori
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, ASST Fatebenefratelli Sacco-Ospedale Luigi Sacco-Polo Universitario and Università Degli Studi di Milano, Milano, Italy
| | - M Schiuma
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, ASST Fatebenefratelli Sacco-Ospedale Luigi Sacco-Polo Universitario and Università Degli Studi di Milano, Milano, Italy
| | - G Lapadula
- Infectious Diseases Unit, Fondazione IRCCS San Gerardo dei Tintori, University of Milano-Bicocca, Monza, Italy
| | - D Goletti
- Stop TB Italy, Milan, Italy
- Translational Research Unit, Epidemiology Department, National Institute for Infectious Diseases-IRCCS L. Spallanzani, Rome, Italy
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4
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Khan MM, Sidorczuk K, Becker J, Aleksandrowicz A, Baraniewicz K, Ludwig C, Ali A, Kingsley RA, Schierack P, Kolenda R. Characterization of clumpy adhesion of Escherichia coli to human cells and associated factors influencing antibiotic sensitivity. Microbiol Spectr 2024; 12:e0260623. [PMID: 38530058 PMCID: PMC11064533 DOI: 10.1128/spectrum.02606-23] [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: 06/24/2023] [Accepted: 03/12/2024] [Indexed: 03/27/2024] Open
Abstract
Escherichia coli intestinal infection pathotypes are characterized by distinct adhesion patterns, including the recently described clumpy adhesion phenotype. Here, we identify and characterize the genetic factors contributing to the clumpy adhesion of E. coli strain 4972. In this strain, the transcriptome and proteome of adhered bacteria were found to be distinct from planktonic bacteria in the supernatant. A total of 622 genes in the transcriptome were differentially expressed in bacteria present in clumps relative to the planktonic bacteria. Seven genes targeted for disruption had variable distribution in different pathotypes and nonpathogenic E. coli, with the pilV and spnT genes being the least frequent or absent from most groups. Deletion (Δ) of five differentially expressed genes, flgH, ffp, pilV, spnT, and yggT, affected motility, adhesion, or antibiotic stress. ΔflgH exhibited 80% decrease and ΔyggT depicted 184% increase in adhesion, and upon complementation, adhesion was significantly reduced to 13%. ΔflgH lost motility and was regenerated when complemented, whereas Δffp had significantly increased motility, and reintroduction of the same gene reduced it to the wild-type level. The clumps produced by Δffp and ΔspnT were more resistant and protected the bacteria, with ΔspnT showing the best clump formation in terms of ampicillin stress protection. ΔyggT had the lowest tolerance to gentamicin, where the antibiotic stress completely eliminated the bacteria. Overall, we were able to investigate the influence of clump formation on cell surface adhesion and antimicrobial tolerance, with the contribution of several factors crucial to clump formation on susceptibility to the selected antibiotics. IMPORTANCE The study explores a biofilm-like clumpy adhesion phenotype in Escherichia coli, along with various factors and implications for antibiotic susceptibility. The phenotype permitted the bacteria to survive the onslaught of high antibiotic concentrations. Profiles of the transcriptome and proteome allowed the differentiation between adhered bacteria in clumps and planktonic bacteria in the supernatant. The deletion mutants of genes differentially expressed between adhered and planktonic bacteria, i.e., flgH, ffp, pilV, spnT, and yggT, and respective complementations in trans cemented their roles in multiple capacities. ffp, an uncharacterized gene, is involved in motility and resistance to ampicillin in a clumpy state. The work also affirms for the first time the role of the yggT gene in adhesion and its involvement in susceptibility against another aminoglycoside antibiotic, i.e., gentamicin. Overall, the study contributes to the mechanisms of biofilm-like adhesion phenotype and understanding of the antimicrobial therapy failures and infections of E. coli.
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Affiliation(s)
- Muhammad Moman Khan
- Institute for Biotechnology, Brandenburg University of Technology (BTU) Cottbus-Senftenberg, Senftenberg, Germany
| | - Katarzyna Sidorczuk
- Department of Bioinformatics and Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Juliane Becker
- Institute for Biotechnology, Brandenburg University of Technology (BTU) Cottbus-Senftenberg, Senftenberg, Germany
| | - Adrianna Aleksandrowicz
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Karolina Baraniewicz
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Wrocław, Poland
| | - Christina Ludwig
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), School of Life Sciences, Technical University Munich (TUM), Munich, Germany
| | - Aamir Ali
- National Institute for Biotechnology and Genetic Engineering College, Pakistan Institute of Engineering and Applied Sciences (NIBGE-C, PIEAS), Faisalabad, Pakistan
| | - Robert A. Kingsley
- Quadram Institute Biosciences, Norwich Research Park, Norwich, United Kingdom
| | - Peter Schierack
- Institute for Biotechnology, Brandenburg University of Technology (BTU) Cottbus-Senftenberg, Senftenberg, Germany
| | - Rafał Kolenda
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
- Quadram Institute Biosciences, Norwich Research Park, Norwich, United Kingdom
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5
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Islam MM, Saha S, Sahoo P, Mandal S. Endophytic Streptomyces sp. MSARE05 isolated from roots of Peanut plant produces a novel antimicrobial compound. J Appl Microbiol 2024; 135:lxae051. [PMID: 38419296 DOI: 10.1093/jambio/lxae051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/18/2024] [Accepted: 02/27/2024] [Indexed: 03/02/2024]
Abstract
AIM This study aimed to isolate, endophytic Streptomyces sp. MSARE05 isolated from root of a peanut (Arachis hypogaea) inhibits the growth of other bacteria. The research focused on characterizing the strain and the antimicrobial compound. METHODS AND RESULTS The surface-sterilized peanut roots were used to isolate the endophytic bacterium Streptomyces sp. MSARE05. A small-scale fermentation was done to get the antimicrobial compound SM05 produced in highest amount in ISP-2 medium (pH 7) for 7 days at 30°C in shaking (180 rpm) condition. Extraction, purification, and chemical analysis of the antibacterial component revealed a novel class of antibiotics with a 485.54 Dalton molecular weight. The MIC was 0.4-0.8 µg ml-1 against the tested pathogens. It also inhibits multidrug-resistant (MDR) pathogens and Mycobacterium with 0.8-3.2 µg ml-1 MIC. SM05 was found to disrupt cell membrane of target pathogen as evident by significant leakage of intracellular proteins and nucleic acids. It showed synergistic activity with ampicillin, chloramphenicol, streptomycin, and kanamycin. CONCLUSIONS The new-class antimicrobial SM05 consisting naphthalene core moiety was effective against drug-resistant pathogens but non-cytotoxic to human cells. This study underscores the significance of endophytic Streptomyces as a source of innovative antibiotics, contributing to the ongoing efforts to combat antibiotic resistance.
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Affiliation(s)
- Md Majharul Islam
- Laboratory of Molecular Bacteriology, Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India
| | - Shrabani Saha
- The Molecular Recognition Laboratory, Department of Chemistry, Visva-Bharati University, Siksha Bhavana, Santiniketan, Birbhum 731235, India
| | - Prithidipa Sahoo
- The Molecular Recognition Laboratory, Department of Chemistry, Visva-Bharati University, Siksha Bhavana, Santiniketan, Birbhum 731235, India
| | - Sukhendu Mandal
- Laboratory of Molecular Bacteriology, Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India
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6
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Heidarian S, Guliaev A, Nicoloff H, Hjort K, Andersson DI. High prevalence of heteroresistance in Staphylococcus aureus is caused by a multitude of mutations in core genes. PLoS Biol 2024; 22:e3002457. [PMID: 38175839 PMCID: PMC10766187 DOI: 10.1371/journal.pbio.3002457] [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: 09/11/2023] [Accepted: 11/30/2023] [Indexed: 01/06/2024] Open
Abstract
Heteroresistance (HR) is an enigmatic phenotype where, in a main population of susceptible cells, small subpopulations of resistant cells exist. This is a cause for concern, as this small subpopulation is difficult to detect by standard antibiotic susceptibility tests, and upon antibiotic exposure the resistant subpopulation may increase in frequency and potentially lead to treatment complications or failure. Here, we determined the prevalence and mechanisms of HR for 40 clinical Staphylococcus aureus isolates, against 6 clinically important antibiotics: daptomycin, gentamicin, linezolid, oxacillin, teicoplanin, and vancomycin. High frequencies of HR were observed for gentamicin (69.2%), oxacillin (27%), daptomycin (25.6%), and teicoplanin (15.4%) while none of the isolates showed HR toward linezolid or vancomycin. Point mutations in various chromosomal core genes, including those involved in membrane and peptidoglycan/teichoic acid biosynthesis and transport, tRNA charging, menaquinone and chorismite biosynthesis and cyclic-di-AMP biosynthesis, were the mechanisms responsible for generating the resistant subpopulations. This finding is in contrast to gram-negative bacteria, where increased copy number of bona fide resistance genes via tandem gene amplification is the most prevalent mechanism. This difference can be explained by the observation that S. aureus has a low content of resistance genes and absence of the repeat sequences that allow tandem gene amplification of these genes as compared to gram-negative species.
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Affiliation(s)
- Sheida Heidarian
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Andrei Guliaev
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Hervé Nicoloff
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Karin Hjort
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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7
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Lang M, Carvalho A, Baharoglu Z, Mazel D. Aminoglycoside uptake, stress, and potentiation in Gram-negative bacteria: new therapies with old molecules. Microbiol Mol Biol Rev 2023; 87:e0003622. [PMID: 38047635 PMCID: PMC10732077 DOI: 10.1128/mmbr.00036-22] [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] [Indexed: 12/05/2023] Open
Abstract
SUMMARYAminoglycosides (AGs) are long-known molecules successfully used against Gram-negative pathogens. While their use declined with the discovery of new antibiotics, they are now classified as critically important molecules because of their effectiveness against multidrug-resistant bacteria. While they can efficiently cross the Gram-negative envelope, the mechanism of AG entry is still incompletely understood, although this comprehension is essential for the development of new therapies in the face of the alarming increase in antibiotic resistance. Increasing antibiotic uptake in bacteria is one strategy to enhance effective treatments. This review aims, first, to consolidate old and recent knowledge about AG uptake; second, to explore the connection between AG-dependent bacterial stress and drug uptake; and finally, to present new strategies of potentiation of AG uptake for more efficient antibiotic therapies. In particular, we emphasize on the connection between sugar transport and AG potentiation.
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Affiliation(s)
- Manon Lang
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - André Carvalho
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Zeynep Baharoglu
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Didier Mazel
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
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8
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Choi JS, Ahn YJ, Lee S, Park DJ, Park J, Ha SM, Seo YJ. Role of Kir4.1 Channels in Aminoglycoside-Induced Ototoxicity of Hair Cells. BIOMED RESEARCH INTERNATIONAL 2023; 2023:4191999. [PMID: 38143588 PMCID: PMC10748730 DOI: 10.1155/2023/4191999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/27/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023]
Abstract
The Kir4.1 channel, an inwardly rectifying potassium ion (K+) channel, is located in the hair cells of the organ of Corti as well as the intermediate cells of the stria vascularis. The Kir4.1 channel has a crucial role in the generation of endolymphatic potential and maintenance of the resting membrane potential. However, the role and functions of the Kir4.1 channel in the progenitor remain undescribed. To observe the role of Kir4.1 in the progenitor treated with the one-shot ototoxic drugs (kanamycin and furosemide), we set the proper condition in culturing Immortomouse-derived HEI-OC1 cells to express the potassium-related channels well. And also, that was reproduced in mice experiments to show the important role of Kir4.1 in the survival of hair cells after treating the ototoxicity drugs. In our results, when kanamycin and furosemide drugs were cotreated with HEI-OC1 cells, the Kir4.1 channel did not change, but the expression levels of the NKCC1 cotransporter and KCNQ4 channel are decreased. This shows that inward and outward channels were blocked by the two drugs (kanamycin and furosemide). However, noteworthy here is that the expression level of Kir4.1 channel increased when kanamycin was treated alone. This shows that Kir4.1, an inwardly rectifying potassium channel, acts as an outward channel in place of the corresponding channel when the KCNQ4 channel, an outward channel, is blocked. These results suggest that the Kir4.1 channel has a role in maintaining K+ homeostasis in supporting cells, with K+ concentration compensator when the NKCC1 cotransporter and Kv7.4 (KCNQ4) channels are deficient.
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Affiliation(s)
- Jin Sil Choi
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Ye Ji Ahn
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - SuHoon Lee
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Dong Jun Park
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - JeongEun Park
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Sun Mok Ha
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Young Joon Seo
- Research Institute of Hearing Enhancement, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
- Department of Otorhinolaryngology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
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9
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Krin E, Carvalho A, Lang M, Babosan A, Mazel D, Baharoglu Z. RavA-ViaA antibiotic response is linked to Cpx and Zra2 envelope stress systems in Vibrio cholerae. Microbiol Spectr 2023; 11:e0173023. [PMID: 37861314 PMCID: PMC10848872 DOI: 10.1128/spectrum.01730-23] [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: 04/25/2023] [Accepted: 09/08/2023] [Indexed: 10/21/2023] Open
Abstract
IMPORTANCE The RavA-ViaA complex was previously found to sensitize Escherichia coli to aminoglycosides (AGs) in anaerobic conditions, but the mechanism is unknown. AGs are antibiotics known for their high efficiency against Gram-negative bacteria. In order to elucidate how the expression of the ravA-viaA genes increases bacterial susceptibility to aminoglycosides, we aimed at identifying partner functions necessary for increased tolerance in the absence of RavA-ViaA, in Vibrio cholerae. We show that membrane stress response systems Cpx and Zra2 are required in the absence of RavA-ViaA, for the tolerance to AGs and for outer membrane integrity. In the absence of these systems, the ∆ravvia strain's membrane becomes permeable to external agents such as the antibiotic vancomycin.
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Affiliation(s)
- Evelyne Krin
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - André Carvalho
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, Collège doctoral, Paris, France
| | - Manon Lang
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, Collège doctoral, Paris, France
| | - Anamaria Babosan
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Didier Mazel
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Zeynep Baharoglu
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
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10
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Magaña AJ, Sklenicka J, Pinilla C, Giulianotti M, Chapagain P, Santos R, Ramirez MS, Tolmasky ME. Restoring susceptibility to aminoglycosides: identifying small molecule inhibitors of enzymatic inactivation. RSC Med Chem 2023; 14:1591-1602. [PMID: 37731693 PMCID: PMC10507813 DOI: 10.1039/d3md00226h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/21/2023] [Indexed: 09/22/2023] Open
Abstract
Growing resistance to antimicrobial medicines is a critical health problem that must be urgently addressed. Adding to the increasing number of patients that succumb to infections, there are other consequences to the rise in resistance like the compromise of several medical procedures and dental work that are heavily dependent on infection prevention. Since their introduction in the clinics, aminoglycoside antibiotics have been a critical component of the armamentarium to treat infections. Still, the increase in resistance and their side effects led to a decline in their utilization. However, numerous current factors, like the urgent need for antimicrobials and their favorable properties, led to renewed interest in these drugs. While efforts to design new classes of aminoglycosides refractory to resistance mechanisms and with fewer toxic effects are starting to yield new promising molecules, extending the useful life of those already in use is essential. For this, numerous research projects are underway to counter resistance from different angles, like inhibition of expression or activity of resistance components. This review focuses on selected examples of one aspect of this quest, the design or identification of small molecule inhibitors of resistance caused by enzymatic modification of the aminoglycoside. These compounds could be developed as aminoglycoside adjuvants to overcome resistant infections.
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Affiliation(s)
- Angel J Magaña
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton Fullerton CA 92831 USA
| | - Jan Sklenicka
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton Fullerton CA 92831 USA
| | - Clemencia Pinilla
- Center for Translational Science, Florida International University Port St. Lucie FL 34987 USA
| | - Marc Giulianotti
- Center for Translational Science, Florida International University Port St. Lucie FL 34987 USA
| | - Prem Chapagain
- Department of Physics, Florida International University Miami FL 33199 USA
- Biomolecular Sciences Institute, Florida International University Miami FL 33199 USA
| | - Radleigh Santos
- Department of Mathematics, Nova Southeastern University Fort Lauderdale FL 33314 USA
| | - Maria Soledad Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton Fullerton CA 92831 USA
| | - Marcelo E Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton Fullerton CA 92831 USA
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11
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Golparian D, Jacobsson S, Holley CL, Shafer WM, Unemo M. High-level in vitro resistance to gentamicin acquired in a stepwise manner in Neisseria gonorrhoeae. J Antimicrob Chemother 2023; 78:1769-1778. [PMID: 37253051 PMCID: PMC10517096 DOI: 10.1093/jac/dkad168] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 05/10/2023] [Indexed: 06/01/2023] Open
Abstract
OBJECTIVES Gentamicin is used in several alternative treatments for gonorrhoea. Verified clinical Neisseria gonorrhoeae isolates with gentamicin resistance are mainly lacking and understanding the mechanisms for gonococcal gentamicin resistance is imperative. We selected gentamicin resistance in gonococci in vitro, identified the novel gentamicin-resistance mutations, and examined the biofitness of a high-level gentamicin-resistant mutant. METHODS Low- and high-level gentamicin resistance was selected in WHO X (gentamicin MIC = 4 mg/L) on gentamicin-gradient agar plates. Selected mutants were whole-genome sequenced. Potential gentamicin-resistance fusA mutations were transformed into WT strains to verify their impact on gentamicin MICs. The biofitness of high-level gentamicin-resistant mutants was examined using a competitive assay in a hollow-fibre infection model. RESULTS WHO X mutants with gentamicin MICs of up to 128 mg/L were selected. Primarily selected fusA mutations were further investigated, and fusAR635L and fusAM520I + R635L were particularly interesting. Different mutations in fusA and ubiM were found in low-level gentamicin-resistant mutants, while fusAM520I was associated with high-level gentamicin resistance. Protein structure predictions showed that fusAM520I is located in domain IV of the elongation factor-G (EF-G). The high-level gentamicin-resistant WHO X mutant was outcompeted by the gentamicin-susceptible WHO X parental strain, suggesting lower biofitness. CONCLUSIONS We describe the first high-level gentamicin-resistant gonococcal isolate (MIC = 128 mg/L), which was selected in vitro through experimental evolution. The most substantial increases of the gentamicin MICs were caused by mutations in fusA (G1560A and G1904T encoding EF-G M520I and R635L, respectively) and ubiM (D186N). The high-level gentamicin-resistant N. gonorrhoeae mutant showed impaired biofitness.
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Affiliation(s)
- Daniel Golparian
- Department of Laboratory Medicine, Microbiology, Faculty of Medicine and Health, WHO Collaborating Centre for Gonorrhoea and Other Sexually Transmitted Infections, Örebro University, Örebro, Sweden
| | - Susanne Jacobsson
- Department of Laboratory Medicine, Microbiology, Faculty of Medicine and Health, WHO Collaborating Centre for Gonorrhoea and Other Sexually Transmitted Infections, Örebro University, Örebro, Sweden
| | - Concerta L Holley
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- The Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center, Decatur, GA, USA
| | - Magnus Unemo
- Department of Laboratory Medicine, Microbiology, Faculty of Medicine and Health, WHO Collaborating Centre for Gonorrhoea and Other Sexually Transmitted Infections, Örebro University, Örebro, Sweden
- Institute for Global Health, University College London (UCL), London, UK
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12
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Yong M, Kok ZY, Koh CH, Zhong W, Ng JT, Mu Y, Chan-Park MB, Gan YH. Membrane Potential-Dependent Uptake of Cationic Oligoimidazolium Mediates Bacterial DNA Damage and Death. Antimicrob Agents Chemother 2023; 67:e0035523. [PMID: 37125913 DOI: 10.1128/aac.00355-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
The treatment of bacterial infections is becoming increasingly challenging with the emergence of antimicrobial resistance. Thus, the development of antimicrobials with novel mechanisms of action is much needed. Previously, we designed several cationic main-chain imidazolium compounds and identified the polyimidazolium PIM1 as a potent antibacterial against a wide panel of multidrug-resistant nosocomial pathogens, and it had relatively low toxicity against mammalian epithelial cells. However, little is known about the mechanism of action of PIM1. Using an oligomeric version of PIM1 with precisely six repeating units (OIM1-6) to control for consistency, we showed that OIM1-6 relies on an intact membrane potential for entry into the bacterial cytoplasm, as resistant mutants to OIM1-6 have mutations in their electron transport chains. These mutants demonstrate reduced uptake of the compound, which can be circumvented through the addition of a sub-MIC dose of colistin. Once taken up intracellularly, OIM1-6 exerts double-stranded DNA breaks. Its potency and ability to kill represents a promising class of drugs that can be combined with membrane-penetrating drugs to potentiate activity and hedge against the rise of resistant mutants. In summary, we discovered that cationic antimicrobial OIM1-6 exhibits an antimicrobial property that is dissimilar to the conventional cationic antimicrobial compounds. Its killing mechanism does not involve membrane disruption but instead depends on the membrane potential for uptake into bacterial cells so that it can exert its antibacterial effect intracellularly.
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Affiliation(s)
- Melvin Yong
- Department of Biochemistry, Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Zhi Y Kok
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Centre for Antimicrobial Bioengineering, Nanyang Technological University, Singapore, Singapore
| | - Chong H Koh
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Centre for Antimicrobial Bioengineering, Nanyang Technological University, Singapore, Singapore
| | - Wenbin Zhong
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Centre for Antimicrobial Bioengineering, Nanyang Technological University, Singapore, Singapore
| | - Justin Ty Ng
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yuguang Mu
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Mary B Chan-Park
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, Singapore
- Centre for Antimicrobial Bioengineering, Nanyang Technological University, Singapore, Singapore
| | - Yunn-Hwen Gan
- Department of Biochemistry, Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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13
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Abstract
Aminoglycosides (AG) have been used against Gram-negative bacteria for decades. Yet, how bacterial metabolism and environmental conditions modify AG toxicity is poorly understood. Here, we show that the level of AG susceptibility varies depending on the nature of the respiratory chain that Escherichia coli uses for growth, i.e., oxygen, nitrate, or fumarate. We show that all components of the fumarate respiratory chain, namely, hydrogenases 2 and 3, the formate hydrogenlyase complex, menaquinone, and fumarate reductase are required for AG-mediated killing under fumarate respiratory conditions. In addition, we show that the AAA+ ATPase RavA and its Von Wildebrand domain-containing partner, ViaA, are essential for AG to act under fumarate respiratory conditions. This effect was true for all AG that were tested but not for antibiotics from other classes. In addition, we show that the sensitizing effect of RavA-ViaA is due to increased gentamicin uptake in a proton motive force-dependent manner. Interestingly, the sensitizing effect of RavA-ViaA was prominent in poor energy conservation conditions, i.e., with fumarate, but dispensable under high energy conservation conditions, i.e., in the presence of nitrate or oxygen. We propose that RavA-ViaA can facilitate uptake of AG across the membrane in low-energy cellular states. IMPORTANCE Antibiotic resistance is a major public health, social, and economic problem. Aminoglycosides (AG) are known to be highly effective against Gram-negative bacteria, but their use is limited to life-threatening infections because of their nephrotoxicity and ototoxicity at therapeutic dose. Elucidation of AG-sensitization mechanisms in bacteria would allow reduced effective doses of AG. Here, we have identified the molecular components involved in anaerobic fumarate respiration that are required for AG to kill. In addition to oxidoreductases and menaquinone, this includes new molecular players, RavA, an AAA+ ATPase, and ViaA, its partner that has the VWA motif. Remarkably, the influence of RavA-ViaA on AG susceptibility varies according to the type of bioenergetic metabolism used by E. coli. This is a significant advance because anaerobiosis is well known to reduce the antibacterial activity of AG. This study highlights the critical importance of the relationship between culture conditions, metabolism, and antibiotic susceptibility.
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14
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Das P, Kundu S, Maiti PK, Mandal S, Sahoo P, Mandal S. An antibacterial compound pyrimidomycin produced by Streptomyces sp. PSAA01 isolated from soil of Eastern Himalayan foothill. Sci Rep 2022; 12:10176. [PMID: 35715695 PMCID: PMC9206078 DOI: 10.1038/s41598-022-14549-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
Selective isolation of soil Actinobacteria was undertaken to isolate a new class of antibiotics and bioactive molecules. A Streptomyces sp. PSAA01 (= MTCC 13,157), isolated from soil of Eastern Himalaya foothill was cultivated on a large scale for the production of the antimicrobial SM02. It has been found that the maximum amount of SM02 produced while PSAA01 was grown in ISP-2 medium (pH 7.0) for 7 days at 30 °C in shaking (180 rpm) condition. A significant zone of inhibition against Staphylococcus aureus MTCC 96 has been found with the crude cell-free culture media (50 µL) of 7 days grown PSAA01. After the purification and chemical structural characterization, we found that SM02 is a new antimicrobial having 746 dalton molecular weight. The compound SM02 contains pyrimidine moiety in it and is produced by a species of Streptomyces and thus we have named this antibiotic pyrimidomycin. The antimicrobial spectrum of pyrimidomycin has been found to be restricted in Gram-positive organisms with a MIC of 12 µg/mL. SM02 was found active against Mycobacterium sp. and also multi-drug resistant Gram-positive bacteria with similar potency and found to disrupt the bacterial cell wall. Pyrimidomycin also showed significant impairment in the biofilm formation by S. aureus. Furthermore, pyrimidomycin showed synergy with the most used antibiotic like ampicillin, vancomycin and chloramphenicol. Pyrimidomycin did not have cytotoxicity towards human cell lines indicating its limited activity within bacteria.
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Affiliation(s)
- Prasenjit Das
- Laboratory of Molecular Bacteriology, Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India
| | - Shampa Kundu
- The Molecular Recognition Laboratory, Department of Chemistry, Visva-Bharati University, Siksha Bhavana, Santiniketan, Birbhum, West Bengal, 731235, India
| | - Pulak Kumar Maiti
- Laboratory of Molecular Bacteriology, Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India
| | - Saurodeep Mandal
- The Molecular Recognition Laboratory, Department of Chemistry, Visva-Bharati University, Siksha Bhavana, Santiniketan, Birbhum, West Bengal, 731235, India
| | - Prithidipa Sahoo
- The Molecular Recognition Laboratory, Department of Chemistry, Visva-Bharati University, Siksha Bhavana, Santiniketan, Birbhum, West Bengal, 731235, India.
| | - Sukhendu Mandal
- Laboratory of Molecular Bacteriology, Department of Microbiology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.
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15
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Kim J, Hemachandran S, Cheng AG, Ricci AJ. Identifying targets to prevent aminoglycoside ototoxicity. Mol Cell Neurosci 2022; 120:103722. [PMID: 35341941 PMCID: PMC9177639 DOI: 10.1016/j.mcn.2022.103722] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/14/2022] [Accepted: 03/19/2022] [Indexed: 12/21/2022] Open
Abstract
Aminoglycosides are potent antibiotics that are commonly prescribed worldwide. Their use carries significant risks of ototoxicity by directly causing inner ear hair cell degeneration. Despite their ototoxic side effects, there are currently no approved antidotes. Here we review recent advances in our understanding of aminoglycoside ototoxicity, mechanisms of drug transport, and promising sites for intervention to prevent ototoxicity.
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Affiliation(s)
- Jinkyung Kim
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sriram Hemachandran
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alan G Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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16
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Darlow CA, da Costa RMA, Ellis S, Franceschi F, Sharland M, Piddock L, Das S, Hope W. Potential Antibiotics for the Treatment of Neonatal Sepsis Caused by Multidrug-Resistant Bacteria. Paediatr Drugs 2021; 23:465-484. [PMID: 34435316 PMCID: PMC8418595 DOI: 10.1007/s40272-021-00465-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/04/2021] [Indexed: 01/26/2023]
Abstract
Neonatal sepsis causes up to an estimated 680,000 deaths annually worldwide, predominantly in low- and middle-income countries (LMICs). A significant and growing proportion of bacteria causing neonatal sepsis are resistant to multiple antibiotics, including the World Health Organization-recommended empiric neonatal sepsis regimen of ampicillin/gentamicin. The Global Antibiotic Research and Development Partnership is aiming to develop alternative empiric antibiotic regimens that fulfil several criteria: (1) affordable in LMIC settings; (2) activity against neonatal bacterial pathogens, including extended-spectrum β-lactamase producers, gentamicin-resistant Gram-negative bacteria, and methicillin-resistant Staphylococcus aureus (MRSA); (3) a licence for neonatal use or extensive experience of use in neonates; and (4) minimal toxicities. In this review, we identify five antibiotics that fulfil these criteria: amikacin, tobramycin, fosfomycin, flomoxef, and cefepime. We describe the available characteristics of each in terms of mechanism of action, resistance mechanisms, clinical pharmacokinetics, pharmacodynamics, and toxicity profile. We also identify some knowledge gaps: (1) the neonatal pharmacokinetics of cefepime is reliant on relatively small and limited datasets, and the pharmacokinetics of flomoxef are also reliant on data from a limited demographic range and (2) for all reviewed agents, the pharmacodynamic index and target has not been definitively established for both bactericidal effect and emergence of resistance, with many assumed to have an identical index/target to similar class molecules. These five agents have the potential to be used in novel combination empiric regimens for neonatal sepsis. However, the data gaps need addressing by pharmacokinetic trials and pharmacodynamic characterisation.
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Affiliation(s)
- Christopher A Darlow
- Antimicrobial Pharmacodynamics and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool Health Partners, William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK.
| | | | - Sally Ellis
- Global Antibiotic Research and Development Partnership, Geneva, Switzerland
| | | | - Mike Sharland
- Paediatric Infectious Diseases Research Group, St George's University of London, London, UK
| | - Laura Piddock
- Global Antibiotic Research and Development Partnership, Geneva, Switzerland
- Antimicrobials Research Group, Institute for Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Shampa Das
- Antimicrobial Pharmacodynamics and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool Health Partners, William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
| | - William Hope
- Antimicrobial Pharmacodynamics and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool Health Partners, William Henry Duncan Building, 6 West Derby Street, Liverpool, L7 8TX, UK
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17
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Raaijmakers J, Schildkraut JA, Hoefsloot W, van Ingen J. The role of amikacin in the treatment of nontuberculous mycobacterial disease. Expert Opin Pharmacother 2021; 22:1961-1974. [PMID: 34292097 DOI: 10.1080/14656566.2021.1953472] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Introduction: Guidelines recommend the use of amikacin in the treatment of nontuberculous mycobacterial (NTM) disease. The authors have evaluated the evidence for the position of amikacin in NTM disease treatment.Areas covered: The authors performed a literature search for original research on amikacin in NTM disease, including its mechanism of action, emergence of resistance, pre-clinical and clinical investigations.Expert opinion: Amikacin shows moderate in vitro activity against the clinically most relevant NTM species (M. avium complex and M. abscessus). It is synergistic with ethambutol, clofazimine, and macrolides and these combinations are effective in animal models. Liposomal encapsulation increases amikacin efficacy. Clinically, the recommended dose of 15 mg/kg intravenous amikacin does not lead to PK/PD target attainment in all patients and a positive impact on long-term treatment outcomes remains unproven in both M. avium complex and M. abscessus disease. Adding the amikacin liposome inhalation suspension did prove to be effective in short and long term in patients not responding to recommended treatment for M. avium complex pulmonary disease. Its optimal use in M. avium complex and M. abscessus pulmonary disease warrants further evaluation.
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Affiliation(s)
- Jelmer Raaijmakers
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jodie Anne Schildkraut
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wouter Hoefsloot
- Radboudumc Center for Infectious Diseases, Department of Pulmonary Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jakko van Ingen
- Radboudumc Center for Infectious Diseases, Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
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18
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Hörömpöli D, Ciglia C, Glüsenkamp KH, Haustedt LO, Falkenstein-Paul H, Bendas G, Berscheid A, Brötz-Oesterhelt H. The Antibiotic Negamycin Crosses the Bacterial Cytoplasmic Membrane by Multiple Routes. Antimicrob Agents Chemother 2021; 65:e00986-20. [PMID: 33468467 PMCID: PMC8097410 DOI: 10.1128/aac.00986-20] [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: 05/15/2020] [Accepted: 01/12/2021] [Indexed: 11/26/2022] Open
Abstract
Negamycin is a natural pseudodipeptide antibiotic with promising activity against Gram-negative and Gram-positive bacteria, including Enterobacteriaceae, Pseudomonas aeruginosa, and Staphylococcus aureus, and good efficacy in infection models. It binds to ribosomes with a novel binding mode, stimulating miscoding and inhibiting ribosome translocation. We were particularly interested in studying how the small, positively charged natural product reaches its cytoplasmic target in Escherichia coli Negamycin crosses the cytoplasmic membrane by multiple routes depending on environmental conditions. In a peptide-free medium, negamycin uses endogenous peptide transporters for active translocation, preferentially the dipeptide permease Dpp. However, in the absence of functional Dpp or in the presence of outcompeting nutrient peptides, negamycin can still enter the cytoplasm. We observed a contribution of the DppA homologs SapA and OppA, as well as of the proton-dependent oligopeptide transporter DtpD. Calcium strongly improves the activity of negamycin against both Gram-negative and Gram-positive bacteria, especially at concentrations around 2.5 mM, reflecting human blood levels. Calcium forms a complex with negamycin and facilitates its interaction with negatively charged phospholipids in bacterial membranes. Moreover, decreased activity at acidic pH and under anaerobic conditions points to a role of the membrane potential in negamycin uptake. Accordingly, improved activity at alkaline pH could be linked to increased uptake of [3H]negamycin. The diversity of options for membrane translocation is reflected by low resistance rates. The example of negamycin demonstrates that membrane passage of antibiotics can be multifaceted and that for cytoplasmic anti-Gram-negative drugs, understanding of permeation and target interaction are equally important.
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Affiliation(s)
- Daniel Hörömpöli
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Microbial Bioactive Compounds, University of Tuebingen, Tuebingen, Germany
- German Center of Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
| | - Catherine Ciglia
- Institute of Pharmaceutical Biology, University of Duesseldorf, Duesseldorf, Germany
| | | | | | - Hildegard Falkenstein-Paul
- Pharmaceutical Institute, Department of Pharmaceutical & Cell Biological Chemistry, University of Bonn, Bonn, Germany
| | - Gerd Bendas
- Pharmaceutical Institute, Department of Pharmaceutical & Cell Biological Chemistry, University of Bonn, Bonn, Germany
| | - Anne Berscheid
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Microbial Bioactive Compounds, University of Tuebingen, Tuebingen, Germany
- German Center of Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
- Institute of Pharmaceutical Biology, University of Duesseldorf, Duesseldorf, Germany
| | - Heike Brötz-Oesterhelt
- Interfaculty Institute of Microbiology and Infection Medicine, Department of Microbial Bioactive Compounds, University of Tuebingen, Tuebingen, Germany
- German Center of Infection Research (DZIF), Partner Site Tuebingen, Tuebingen, Germany
- Institute of Pharmaceutical Biology, University of Duesseldorf, Duesseldorf, Germany
- Cluster of Excellence 2124: Controlling Microbes to Fight Infection, Tuebingen, Germany
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19
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Bruni GN, Kralj JM. Membrane voltage dysregulation driven by metabolic dysfunction underlies bactericidal activity of aminoglycosides. eLife 2020; 9:58706. [PMID: 32748785 PMCID: PMC7406350 DOI: 10.7554/elife.58706] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022] Open
Abstract
Aminoglycosides are broad-spectrum antibiotics whose mechanism of action is under debate. It is widely accepted that membrane voltage potentiates aminoglycoside activity, which is ascribed to voltage-dependent drug uptake. In this paper, we measured the response of Escherichia coli treated with aminoglycosides and discovered that the bactericidal action arises not from the downstream effects of voltage-dependent drug uptake, but rather directly from dysregulated membrane potential. In the absence of voltage, aminoglycosides are taken into cells and exert bacteriostatic effects by inhibiting translation. However, cell killing was immediate upon re-polarization. The hyperpolarization arose from altered ATP flux, which induced a reversal of the F1Fo-ATPase to hydrolyze ATP and generated the deleterious voltage. Heterologous expression of an ATPase inhibitor completely eliminated bactericidal activity, while loss of the F-ATPase reduced the electrophysiological response to aminoglycosides. Our data support a model of voltage-induced death, and separates aminoglycoside bacteriostasis and bactericide in E. coli.
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Affiliation(s)
- Giancarlo Noe Bruni
- BioFrontiers Institute and the Department of Molecular, Cellular, Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Joel M Kralj
- BioFrontiers Institute and the Department of Molecular, Cellular, Developmental Biology, University of Colorado Boulder, Boulder, United States
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20
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Li Q, Tan L, Wang H, Kou Y, Shi X, Zhang S, Pan Y. Fusobacterium nucleatum Interaction with Pseudomonas aeruginosa Induces Biofilm-Associated Antibiotic Tolerance via Fusobacterium Adhesin A. ACS Infect Dis 2020; 6:1686-1696. [PMID: 32320601 DOI: 10.1021/acsinfecdis.9b00402] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Respiratory infections with Pseudomonas aeruginosa or Fusobacterium nucleatum are associated with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and failure in antibiotic treatment. However, the impact of these dual-species interactions on the severity of chronic obstructive pulmonary disease (COPD) and biofilm antibiotic susceptibility remains poorly understood. This study demonstrated that F. nucleatum frequently coexisted with P. aeruginosa in the respiratory tract, and the number of F. nucleatum was negatively correlated with the lung function of AECOPD patients. The coculture of P. aeruginosa and F. nucleatum promoted bacterial proliferation and induced antibiotic tolerance through the formation of a dense biofilm surrounded by excessive Pel and Psl polysaccharides. Moreover, Fusobacterium adhesin A (FadA), rather than F. nucleatum spent medium, induced antibiotic tolerance of the P. aeruginosa biofilm. These results indicate that F. nucleatum is a biomarker of lung function decline in AECOPD patients and interacts with P. aeruginosa in vitro to resist antibiotics via FadA, which would be a potential anti-infective target of these dual-species infection.
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Affiliation(s)
- Qian Li
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Oral Biology, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Lisi Tan
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Hongyan Wang
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Yurong Kou
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Oral Biology, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Xiaoting Shi
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Shuwei Zhang
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
| | - Yaping Pan
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Oral Biology, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
- Liaoning Provincial Key Laboratory of Oral Diseases, Department of Periodontics, School and Hospital of Stomatology, China Medical University, Nanjing North Street 117, Shenyang, Liaoning 110002, China
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21
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Aminoglycoside Revival: Review of a Historically Important Class of Antimicrobials Undergoing Rejuvenation. EcoSal Plus 2019; 8. [PMID: 30447062 DOI: 10.1128/ecosalplus.esp-0002-2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Aminoglycosides are cidal inhibitors of bacterial protein synthesis that have been utilized for the treatment of serious bacterial infections for almost 80 years. There have been approximately 15 members of this class approved worldwide for the treatment of a variety of infections, many serious and life threatening. While aminoglycoside use declined due to the introduction of other antibiotic classes such as cephalosporins, fluoroquinolones, and carbapenems, there has been a resurgence of interest in the class as multidrug-resistant pathogens have spread globally. Furthermore, aminoglycosides are recommended as part of combination therapy for empiric treatment of certain difficult-to-treat infections. The development of semisynthetic aminoglycosides designed to overcome common aminoglycoside resistance mechanisms, and the shift to once-daily dosing, has spurred renewed interest in the class. Plazomicin is the first new aminoglycoside to be approved by the FDA in nearly 40 years, marking the successful start of a new campaign to rejuvenate the class.
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Interplay of Nitric Oxide Synthase (NOS) and SrrAB in Modulation of Staphylococcus aureus Metabolism and Virulence. Infect Immun 2019; 87:IAI.00570-18. [PMID: 30420450 DOI: 10.1128/iai.00570-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/26/2018] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus nitric oxide synthase (saNOS) is a major contributor to virulence, stress resistance, and physiology, yet the specific mechanism(s) by which saNOS intersects with other known regulatory circuits is largely unknown. The SrrAB two-component system, which modulates gene expression in response to the reduced state of respiratory menaquinones, is a positive regulator of nos expression. Several SrrAB-regulated genes were also previously shown to be induced in an aerobically respiring nos mutant, suggesting a potential interplay between saNOS and SrrAB. Therefore, a combination of genetic, molecular, and physiological approaches was employed to characterize a nos srrAB mutant, which had significant reductions in the maximum specific growth rate and oxygen consumption when cultured under conditions promoting aerobic respiration. The nos srrAB mutant secreted elevated lactate levels, correlating with the increased transcription of lactate dehydrogenases. Expression of nitrate and nitrite reductase genes was also significantly enhanced in the nos srrAB double mutant, and its aerobic growth defect could be partially rescued with supplementation with nitrate, nitrite, or ammonia. Furthermore, elevated ornithine and citrulline levels and highly upregulated expression of arginine deiminase genes were observed in the double mutant. These data suggest that a dual deficiency in saNOS and SrrAB limits S. aureus to fermentative metabolism, with a reliance on nitrate assimilation and the urea cycle to help fuel energy production. The nos, srrAB, and nos srrAB mutants showed comparable defects in endothelial intracellular survival, whereas the srrAB and nos srrAB mutants were highly attenuated during murine sepsis, suggesting that SrrAB-mediated metabolic versatility is dominant in vivo.
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Stebegg R, Schmetterer G, Rompel A. Transport of organic substances through the cytoplasmic membrane of cyanobacteria. PHYTOCHEMISTRY 2019; 157:206-218. [PMID: 30447471 DOI: 10.1016/j.phytochem.2018.08.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 07/25/2018] [Accepted: 08/17/2018] [Indexed: 06/09/2023]
Abstract
Cyanobacteria are mainly known to incorporate inorganic molecules like carbon dioxide and ammonia from the environment into organic material within the cell. Nevertheless cyanobacteria do import and export organic substances through the cytoplasmic membrane and these processes are essential for all cyanobacteria. In addition understanding the mechanisms of transport of organic molecules through the cytoplasmic membrane might become very important. Genetically modified strains of cyanobacteria could serve as producers and exporters of commercially important substances. In this review we attempt to present all data of transport of organic molecules through the cytoplasmic membrane of cyanobacteria that are currently available with the transported molecules ordered according to their chemical classes.
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Affiliation(s)
- Ronald Stebegg
- Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, Althanstraße 14, 1090 Wien, Austria(1).
| | - Georg Schmetterer
- Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, Althanstraße 14, 1090 Wien, Austria(1).
| | - Annette Rompel
- Universität Wien, Fakultät für Chemie, Institut für Biophysikalische Chemie, Althanstraße 14, 1090 Wien, Austria(1).
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Amikacin: Uses, Resistance, and Prospects for Inhibition. Molecules 2017; 22:molecules22122267. [PMID: 29257114 PMCID: PMC5889950 DOI: 10.3390/molecules22122267] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 12/16/2022] Open
Abstract
Aminoglycosides are a group of antibiotics used since the 1940s to primarily treat a broad spectrum of bacterial infections. The primary resistance mechanism against these antibiotics is enzymatic modification by aminoglycoside-modifying enzymes that are divided into acetyl-transferases, phosphotransferases, and nucleotidyltransferases. To overcome this problem, new semisynthetic aminoglycosides were developed in the 70s. The most widely used semisynthetic aminoglycoside is amikacin, which is refractory to most aminoglycoside modifying enzymes. Amikacin was synthesized by acylation with the l-(-)-γ-amino-α-hydroxybutyryl side chain at the C-1 amino group of the deoxystreptamine moiety of kanamycin A. The main amikacin resistance mechanism found in the clinics is acetylation by the aminoglycoside 6'-N-acetyltransferase type Ib [AAC(6')-Ib], an enzyme coded for by a gene found in integrons, transposons, plasmids, and chromosomes of Gram-negative bacteria. Numerous efforts are focused on finding strategies to neutralize the action of AAC(6')-Ib and extend the useful life of amikacin. Small molecules as well as complexes ionophore-Zn+2 or Cu+2 were found to inhibit the acetylation reaction and induced phenotypic conversion to susceptibility in bacteria harboring the aac(6')-Ib gene. A new semisynthetic aminoglycoside, plazomicin, is in advance stage of development and will contribute to renewed interest in this kind of antibiotics.
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Radlinski L, Conlon BP. Antibiotic efficacy in the complex infection environment. Curr Opin Microbiol 2017; 42:19-24. [PMID: 28988156 DOI: 10.1016/j.mib.2017.09.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/06/2017] [Accepted: 09/14/2017] [Indexed: 11/26/2022]
Abstract
Accurate prediction of antimicrobial efficacy is essential for successful treatment of bacterial infection. Beyond genetically encoded mechanisms of antibiotic resistance, the determinants of antibiotic susceptibility during infection remain poorly understood, and treatment failure is common. Traditional antibiotic susceptibility testing fails to account for extrinsic determinants of antibiotic susceptibility present in the complex infection environment and is therefore a poor predictor of antibiotic treatment outcome. Here we discuss how host-pathogen interaction, microbial interspecies interaction, and metabolic heterogeneity contribute to the success or failure of antibiotic therapy. Consideration of these factors during the treatment of disease will improve our ability to successfully resolve recalcitrant bacterial infection and improve patient health.
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Affiliation(s)
- L Radlinski
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, NC, USA
| | - B P Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, NC, USA; Marsico Lung Institute, University of North Carolina at Chapel Hill, NC, USA.
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26
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Das S, Baker AB. Biomaterials and Nanotherapeutics for Enhancing Skin Wound Healing. Front Bioeng Biotechnol 2016; 4:82. [PMID: 27843895 PMCID: PMC5087310 DOI: 10.3389/fbioe.2016.00082] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/11/2016] [Indexed: 02/06/2023] Open
Abstract
Wound healing is an intricate process that requires complex coordination between many cell types and an appropriate extracellular microenvironment. Chronic wounds often suffer from high protease activity, persistent infection, excess inflammation, and hypoxia. While there has been intense investigation to find new methods to improve cutaneous wound care, the management of chronic wounds, burns, and skin wound infection remain challenging clinical problems. Ideally, advanced wound dressings can provide enhanced healing and bridge the gaps in the healing processes that prevent chronic wounds from healing. These technologies have great potential for improving outcomes in patients with poorly healing wounds but face significant barriers in addressing the heterogeneity and clinical complexity of chronic or severe wounds. Active wound dressings aim to enhance the natural healing process and work to counter many aspects that plague poorly healing wounds, including excessive inflammation, ischemia, scarring, and wound infection. This review paper discusses recent advances in the development of biomaterials and nanoparticle therapeutics to enhance wound healing. In particular, this review focuses on the novel cutaneous wound treatments that have undergone significant preclinical development or are currently used in clinical practice.
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Affiliation(s)
- Subhamoy Das
- Department of Biomedical Engineering, University of Texas at Austin , Austin, TX , USA
| | - Aaron B Baker
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA; Institute for Biomaterials, Drug Delivery and Regenerative Medicine, University of Texas at Austin, Austin, TX, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA; Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX, USA
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Multidrug Intrinsic Resistance Factors in Staphylococcus aureus Identified by Profiling Fitness within High-Diversity Transposon Libraries. mBio 2016; 7:mBio.00950-16. [PMID: 27531908 PMCID: PMC4992970 DOI: 10.1128/mbio.00950-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Staphylococcus aureus is a leading cause of life-threatening infections worldwide. The MIC of an antibiotic against S. aureus, as well as other microbes, is determined by the affinity of the antibiotic for its target in addition to a complex interplay of many other cellular factors. Identifying nontarget factors impacting resistance to multiple antibiotics could inform the design of new compounds and lead to more-effective antimicrobial strategies. We examined large collections of transposon insertion mutants in S. aureus using transposon sequencing (Tn-Seq) to detect transposon mutants with reduced fitness in the presence of six clinically important antibiotics—ciprofloxacin, daptomycin, gentamicin, linezolid, oxacillin, and vancomycin. This approach allowed us to assess the relative fitness of many mutants simultaneously within these libraries. We identified pathways/genes previously known to be involved in resistance to individual antibiotics, including graRS and vraFG (graRS/vraFG), mprF, and fmtA, validating the approach, and found several to be important across multiple classes of antibiotics. We also identified two new, previously uncharacterized genes, SAOUHSC_01025 and SAOUHSC_01050, encoding polytopic membrane proteins, as important in limiting the effectiveness of multiple antibiotics. Machine learning identified similarities in the fitness profiles of graXRS/vraFG, SAOUHSC_01025, and SAOUHSC_01050 mutants upon antibiotic treatment, connecting these genes of unknown function to modulation of crucial cell envelope properties. Therapeutic strategies that combine a known antibiotic with a compound that targets these or other intrinsic resistance factors may be of value for enhancing the activity of existing antibiotics for treating otherwise-resistant S. aureus strains. Bacterial resistance to every major class of antibiotics has emerged, and we are entering a “post-antibiotic era” where relatively minor infections can lead to serious complications or even death. The utility of an antibiotic for a specific pathogen is limited by both intrinsic and acquired factors. Identifying the repertoire of intrinsic resistance factors of an antibiotic for Staphylococcus aureus, a leading cause of community- and hospital-acquired infections, would inform the design of new drugs as well as the identification of compounds that enhance the activity of existing drugs. To identify factors that limit the activity of antibiotics against S. aureus, we used Tn-Seq to simultaneously assess fitness of transposon mutants in every nonessential gene in the presence of six clinically important antibiotics. This work provides an efficient approach for identifying promising targets for drugs that can enhance susceptibility or restore sensitivity to existing antibiotics.
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Nguyen AT, Oglesby-Sherrouse AG. Interactions between Pseudomonas aeruginosa and Staphylococcus aureus during co-cultivations and polymicrobial infections. Appl Microbiol Biotechnol 2016; 100:6141-6148. [PMID: 27236810 DOI: 10.1007/s00253-016-7596-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 02/06/2023]
Abstract
Pseudomonas aeruginosa and Staphylococcus aureus are versatile bacterial pathogens and common etiological agents in polymicrobial infections. Microbial communities containing both of these pathogens are shaped by interactions ranging from parasitic to mutualistic, with the net impact of these interactions in many cases resulting in enhanced virulence. Polymicrobial communities of these organisms are further defined by multiple aspects of the host environment, with important implications for disease progression and therapeutic outcomes. This mini-review highlights the impact of these interactions on the host and individual pathogens, the molecular mechanisms that underlie these interactions, and host-specific factors that drive interactions between these two important pathogens.
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Affiliation(s)
- Angela T Nguyen
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA
| | - Amanda G Oglesby-Sherrouse
- School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA. .,School of Medicine, Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, 21201, USA.
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29
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Lin YH, Lin JH, Li TS, Wang SH, Yao CH, Chung WY, Ko TH. Dressing with epigallocatechin gallate nanoparticles for wound regeneration. Wound Repair Regen 2015; 24:287-301. [PMID: 26472668 DOI: 10.1111/wrr.12372] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 10/10/2015] [Indexed: 12/21/2022]
Abstract
Several reagents have been studied to overcome the problems encountered with antiseptic use, such as moderate cutaneous wound cytotoxicity and skin thinning. We successfully prepared a gelatin/chitosan/epigallocatechin gallate nanoparticle incorporated in a poly(γ-glutamic acid)/gelatin hydrogel, which comprised activated carbon fibers with gentamicin, to fabricate a sandwiched dressing to enhance wound regeneration. The inner layer of activated carbon fibers with gentamicin was designed to prevent bacterial infection, and the outer layer of gelatin/chitosan/epigallocatechin gallate nanoparticles incorporated in a poly(γ-glutamic acid)/gelatin hydrogel was designed to prevent inflammation and facilitate reepithelialization. An in vitro study demonstrated that the dressing effectively inhibited target microorganisms, and scanning electron microscope and confocal laser scanning microscope indicated that the nanoparticles were homogeneously dispersed and migrated into the hydrogel. The in vivo study reported that the sandwiched dressing, comprising the poly(γ-glutamic acid)/gelatin hydrogel, was easy to remove from the wound and facilitated wound tissue regeneration and accelerated healing process.
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Affiliation(s)
- Yu-Hsin Lin
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Jui-Hsiang Lin
- Bio-Medical Carbon Technology Co., Ltd., Taichung, Taiwan
| | - Tzong-Shiun Li
- Department of Plastic Surgery, China Medical University Hospital, Taichung, Taiwan.,School of Medicine, China Medical University, Taichung, Taiwan.,Department of Plastic Surgery, Tainan Municipal An-Nan Hospital, Tainan, Taiwan
| | - Shih-Hao Wang
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Chun-Hsu Yao
- Lab of Biomaterials, School of Chinese Medicine, China Medical University, Taichung, Taiwan.,Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Wan-Yu Chung
- Bio-Medical Carbon Technology Co., Ltd., Taichung, Taiwan
| | - Tse-Hao Ko
- Department of Materials Science and Engineering, Feng Chia University, Taichung, Taiwan
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Dai J, Suh SJ, Hamon M, Hong JW. Determination of antibiotic EC50 using a zero-flow microfluidic chip based growth phenotype assay. Biotechnol J 2015; 10:1783-91. [PMID: 26110969 DOI: 10.1002/biot.201500037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 04/30/2015] [Accepted: 06/24/2015] [Indexed: 01/30/2023]
Abstract
Current existing assay systems for evaluating antimicrobial activity suffer from several limitations including excess reagent consumption and inaccurate concentration gradient preparation. Recently, microfluidic systems have been developed to provide miniaturized platforms for antimicrobial susceptibility assays. However, some of current microfluidic based assays require continuous flows of reagents or elaborate preparation steps during concentration preparation. In this study, we introduce a novel microfluidic chip based growth phenotype assay that automatically generates a logarithmic concentration gradient and allows observing the growth of pathogenic bacteria under different concentrations of antibiotics in nanoliter batch culture reactors. We chose pathogen bacterium Pseudomonas aeruginosa as a model strain and evaluated the inhibitory effects of gentamicin and ciprofloxacin. We determined the EC50 values and confirmed the validity of the present system by comparing the EC50 values obtained through conventional test tube method. We demonstrated that the EC50 values acquired from present assay are comparable to those obtained from conventional test tube cultures. The potential application of present assay system for investigating combinatorial effects of antibiotics on multidrug resistant pathogenic bacteria is discussed and it can be further used for systematic evaluation of antifungal or antiviral agents.
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Affiliation(s)
- Jing Dai
- Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL, USA
| | - Sang-Jin Suh
- Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Morgan Hamon
- Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL, USA
| | - Jong Wook Hong
- Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, Auburn, AL, USA. .,Department of Bionano Engineering, Hanyang University, Ansan, Korea.
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31
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Pericás JM, Zboromyrska Y, Cervera C, Castañeda X, Almela M, Garcia-de-la-Maria C, Mestres C, Falces C, Quintana E, Ninot S, Llopis J, Marco F, Moreno A, Miró JM. Enterococcal endocarditis revisited. Future Microbiol 2015; 10:1215-40. [PMID: 26118390 DOI: 10.2217/fmb.15.46] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The Enterococcus species is the third main cause of infective endocarditis (IE) worldwide, and it is gaining relevance, especially among healthcare-associated cases. Patients with enterococcal IE are older and have more comorbidities than other types of IE. Classical treatment options are limited due to the emergence of high-level aminoglycosides resistance (HLAR), vancomycin resistance and multidrug resistance in some cases. Besides, few new antimicrobial alternatives have shown real efficacy, despite some of them being recommended by major guidelines (including linezolid and daptomycin). Ampicillin plus ceftriaxone 2 g iv./12 h is a good option for Enterococcus faecalis IE caused by HLAR strains, but randomized clinical trials are essential to demonstrate its efficacy for non-HLAR EFIE and to compare it with ampicillin plus short-course gentamicin. The main mechanisms of resistance and treatment options are also reviewed for other enterococcal species.
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Affiliation(s)
- J M Pericás
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
| | - Y Zboromyrska
- Clinical Microbiology Service, Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - C Cervera
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
| | - X Castañeda
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
| | - M Almela
- Clinical Microbiology Service, Hospital Clínic, University of Barcelona, Barcelona, Spain
| | - C Garcia-de-la-Maria
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
| | - C Mestres
- Cardiovascular Surgery Service, Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - C Falces
- Cardiology Service, Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - E Quintana
- Cardiovascular Surgery Service, Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - S Ninot
- Cardiovascular Surgery Service, Hospital Clínic-IDIBAPS, University of Barcelona, Barcelona, Spain
| | - J Llopis
- Department of Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - F Marco
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Microbiology Service, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - A Moreno
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
| | - J M Miró
- Infectious Diseases Service, Hospital Clínic-IDIBAPS (Institut d'Investigacions Biomèdiques Pi i Sunyer), University of Barcelona, Barcelona, Spain
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McKinney DC, Bezdenejnih-Snyder N, Farrington K, Guo J, McLaughlin RE, Ruvinsky AM, Singh R, Basarab GS, Narayan S, Buurman ET. Illicit Transport via Dipeptide Transporter Dpp is Irrelevant to the Efficacy of Negamycin in Mouse Thigh Models of Escherichia coli Infection. ACS Infect Dis 2015; 1:222-30. [PMID: 27622650 DOI: 10.1021/acsinfecdis.5b00027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Negamycin is a hydrophilic antimicrobial translation inhibitor that crosses the lipophilic inner membrane of Escherichia coli via at least two transport routes to reach its intracellular target. In a minimal salts medium, negamycin's peptidic nature allows illicit entry via a high-affinity route by hijacking the Dpp dipeptide transporter. Transport via a second, low-affinity route is energetically driven by the membrane potential, seemingly without the direct involvement of a transport protein. In mouse thigh models of E. coli infection, no evidence for Dpp-mediated transport of negamycin was found. The implication is that for the design of new negamycin-based analogs, the physicochemical properties required for cell entry via the low-affinity route need to be retained to achieve clinical success in the treatment of infectious diseases. Furthermore, clinical resistance to such analogs due to mutations affecting their ribosomal target or transport is expected to be rare and similar to that of aminoglycosides.
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Affiliation(s)
- David C. McKinney
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Natascha Bezdenejnih-Snyder
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Krista Farrington
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Jian Guo
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Robert E. McLaughlin
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Anatoly M. Ruvinsky
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Renu Singh
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Gregory S. Basarab
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Sridhar Narayan
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
| | - Ed T. Buurman
- Departments of Chemistry, ‡Biosciences, and §Drug Metabolism and Pharmacokinetics, Infection Innovative Medicines Unit, AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, Massachusetts 02451, United States
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Abstract
Persisters are dormant variants that form a subpopulation of drug-tolerant cells largely responsible for the recalcitrance of chronic infections. However, our understanding of the genetic basis of antibiotic tolerance remains incomplete. In this study, we applied transposon sequencing (Tn-Seq) to systematically investigate the mechanism of aminoglycoside tolerance in Escherichia coli. We constructed a highly saturated transposon library that covered the majority of E. coli genes and promoter regions and exposed a stationary-phase culture to a lethal dose of gentamicin. Tn-Seq was performed to evaluate the survival of each mutant to gentamicin exposure. We found that the disruption of several distinct pathways affected gentamicin tolerance. We identified 105 disrupted gene/promoter regions with a more than 5-fold reduction in gentamicin tolerance and 37 genes with a more than 5-fold increased tolerance. Functional cluster analysis suggests that deficiency in motility and amino acid synthesis significantly diminished persisters tolerant to gentamicin, without changing the MIC. Amino acid auxotrophs, including serine, threonine, glutamine, and tryptophan auxotrophs, exhibit strongly decreased tolerance to gentamicin, which cannot be restored by supplying the corresponding amino acids to the culture. Interestingly, supplying these amino acids to wild-type E. coli sensitizes stationary-phase cells to gentamicin, possibly through the inhibition of amino acid synthesis. In addition, we found that the deletion of amino acid synthesis genes significantly increases gentamicin uptake in stationary phase, while the deletion of flagellar genes does not affect gentamicin uptake. We conclude that activation of motility and amino acid biosynthesis contributes to the formation of persisters tolerant to gentamicin. Persisters are responsible for the recalcitrance of chronic infections to antibiotics. The pathways of persister formation in E. coli are redundant, and our understanding of the mechanism of persister formation is incomplete. Using a highly saturated transposon insertion library, we systematically analyzed the contribution of different cellular processes to the formation of persisters tolerant to aminoglycosides. Unexpectedly, we found that activation of amino acid synthesis and motility strongly contributes to persister formation. The approach used in this study leads to an understanding of aminoglycoside tolerance and provides a general method to identify genes affecting persister formation.
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Optimization of a Solid-Phase Extraction Method for the Determination of 12 Aminoglycosides in Water Samples Using LC–ESI–MS/MS. Chromatographia 2015. [DOI: 10.1007/s10337-015-2877-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Abstract
The metabolic state of a bacterial cell influences its susceptibility to antibiotics. In this issue, Peng et al. (2015) show that resistant bacteria can be sensitized to antibiotic treatment through the addition of exogenous metabolites that stimulate central metabolic pathways and increase drug uptake.
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Affiliation(s)
- Prerna Bhargava
- Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - James J Collins
- Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.
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36
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Cars O, Craig WA. Pharmacodynamics of Antibiotics-Consequences for Dosing: Proceedings of a Symposium Held in Stockholm, June 7–9, 1990. ACTA ACUST UNITED AC 2015. [DOI: 10.3109/inf.1990.22.suppl-74.01] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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37
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Lonergan N, Britt L, Sullivan C. Immobilizing live Escherichia coli for AFM studies of surface dynamics. Ultramicroscopy 2014; 137:30-9. [DOI: 10.1016/j.ultramic.2013.10.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 10/23/2013] [Accepted: 10/25/2013] [Indexed: 11/25/2022]
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Aussel L, Pierrel F, Loiseau L, Lombard M, Fontecave M, Barras F. Biosynthesis and physiology of coenzyme Q in bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1004-11. [PMID: 24480387 DOI: 10.1016/j.bbabio.2014.01.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 11/24/2022]
Abstract
Ubiquinone, also called coenzyme Q, is a lipid subject to oxido-reduction cycles. It functions in the respiratory electron transport chain and plays a pivotal role in energy generating processes. In this review, we focus on the biosynthetic pathway and physiological role of ubiquinone in bacteria. We present the studies which, within a period of five decades, led to the identification and characterization of the genes named ubi and involved in ubiquinone production in Escherichia coli. When available, the structures of the corresponding enzymes are shown and their biological function is detailed. The phenotypes observed in mutants deficient in ubiquinone biosynthesis are presented, either in model bacteria or in pathogens. A particular attention is given to the role of ubiquinone in respiration, modulation of two-component activity and bacterial virulence. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Laurent Aussel
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France
| | - Fabien Pierrel
- Laboratoire de Chimie et Biologie des Métaux, UMR 5249 CEA - Université Grenoble I - CNRS, 17 Rue des Martyrs, 38054 Grenoble Cedex France
| | - Laurent Loiseau
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC, Collège de France, 11 Place Marcellin Berthelot, 75231 Paris Cedex 05 France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC, Collège de France, 11 Place Marcellin Berthelot, 75231 Paris Cedex 05 France
| | - Frédéric Barras
- Laboratoire de Chimie Bactérienne, UMR 7283 Aix-Marseille Université - CNRS, Institut de Microbiologie de la Méditerranée, 31 Chemin Joseph Aiguier 13009 Marseille, France.
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Raivio TL. Everything old is new again: an update on current research on the Cpx envelope stress response. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:1529-41. [PMID: 24184210 DOI: 10.1016/j.bbamcr.2013.10.018] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 10/26/2022]
Abstract
The Cpx envelope stress response (ESR) has been linked to proteins that are integrated into and secreted across the inner membrane for several decades. Initial studies of the cpx locus linked it to alterations in the protein content of both the inner and outer membrane, together with changes in proton motive driven transport and conjugation. Since the mid 1990s, the predominant view of the Cpx envelope stress response has been that it serves to detect and respond to secreted, misfolded proteins in the periplasm. Recent studies in Escherichia coli and other Gram negative organisms highlight a role for the Cpx ESR in specifically responding to perturbations that occur at the inner membrane (IM). It is clear that Cpx adaptation involves a broad suite of changes that encompass many functions in addition to protein folding. Interestingly, recent studies have refocused attention on Cpx-regulated phenotypes that were initially published over 30years ago, including antibiotic resistance and transport across the IM. In this review I will focus on the insights and models that have arisen from recent studies and that may help explain some of the originally published Cpx phenotypes. Although the molecular nature of the inducing signal for the Cpx ESR remains enigmatic, recently solved structures of signaling proteins are yielding testable models concerning the molecular mechanisms behind signaling. The identification of connections between the Cpx ESR and other stress responses in the cell reveals a complex web of interactions that involves Cpx-regulated expression of other regulators as well as small proteins and sRNAs. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Tracy L Raivio
- Department of Biological Sciences, Centennial Centre for Interdisciplinary Science, University of Alberta, Edmonton, AB T6G 2E9, Canada
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Buckley LM, McEwan NA, Nuttall T. Tris-EDTA significantly enhances antibiotic efficacy against multidrug-resistantPseudomonas aeruginosa in vitro. Vet Dermatol 2013; 24:519-e122. [DOI: 10.1111/vde.12071] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Laura M. Buckley
- School of Veterinary Science; The University of Liverpool; Leahurst Campus; Neston; Cheshire; CH64 7TE; UK
| | - Neil A. McEwan
- School of Veterinary Science; The University of Liverpool; Leahurst Campus; Neston; Cheshire; CH64 7TE; UK
| | - Tim Nuttall
- The Royal (Dick) School of Veterinary Studies; Easter Bush Veterinary Centre; The University of Edinburgh; Roslin; Midlothian; EH25 9RG; UK
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Abstract
Aminoglycoside antibiotics were among the first antibiotics discovered and used clinically. Although they have never completely fallen out of favor, their importance has waned due to the emergence of other broad-spectrum antibiotics with fewer side effects. Today, with the dramatically increasing rate of infections caused by multidrug-resistant bacteria, focus has returned to aminoglycoside antibiotics as one of the few remaining treatment options, particularly for Gram-negative pathogens. Although the mechanisms of resistance are reasonably well understood, our knowledge about the mode of action of aminoglycosides is still far from comprehensive. In the face of emerging bacterial infections that are virtually untreatable, it is time to have a fresh look at this old class to reinvigorate the struggle against multidrug-resistant pathogens.
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Affiliation(s)
- Bernd Becker
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, Brisbane,
Queensland 4072, Australia
| | - Matthew A. Cooper
- Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, Brisbane,
Queensland 4072, Australia
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Characterization of Escherichia coli D-cycloserine transport and resistant mutants. J Bacteriol 2013; 195:1389-99. [PMID: 23316042 DOI: 10.1128/jb.01598-12] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
d-Cycloserine (DCS) is a broad-spectrum antibiotic that inhibits d-alanine ligase and alanine racemase activity. When Escherichia coli K-12 or CFT073 is grown in minimal glucose or glycerol medium, CycA transports DCS into the cell. E. coli K-12 cycA and CFT073 cycA mutant strains display increased DCS resistance when grown in minimal medium. However, the cycA mutants exhibit no change in DCS sensitivity compared to their parental strains when grown in LB (CFT073 and K-12) or human urine (CFT073 only). These data suggest that cycA does not participate in DCS sensitivity when strains are grown in a non-minimal medium. The small RNA GvcB acts as a negative regulator of E. coli K-12 cycA expression when grown in LB. Three E. coli K-12 gcvB mutant strains failed to demonstrate a change in DCS sensitivity when grown in LB. This further suggests a limited role for cycA in DCS sensitivity. To aid in the identification of E. coli genes involved in DCS sensitivity when grown on complex media, the Keio K-12 mutant collection was screened for DCS-resistant strains. dadA, pnp, ubiE, ubiF, ubiG, ubiH, and ubiX mutant strains showed elevated DCS resistance. The phenotypes associated with these mutants were used to further define three previously characterized E. coli DCS-resistant strains (χ316, χ444, and χ453) isolated by Curtiss and colleagues (R. Curtiss, III, L. J. Charamella, C. M. Berg, and P. E. Harris, J. Bacteriol. 90:1238-1250, 1965). A dadA mutation was identified in both χ444 and χ453. In addition, results are presented that indicate for the first time that DCS can antagonize d-amino acid dehydrogenase (DadA) activity.
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Determinants of intrinsic aminoglycoside resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2012; 56:5591-602. [PMID: 22908149 DOI: 10.1128/aac.01446-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Screening of a transposon insertion mutant library of Pseudomonas aeruginosa for increased susceptibility to paromomycin identified a number of genes whose disruption enhanced susceptibility of this organism to multiple aminoglycosides, including tobramycin, amikacin, and gentamicin. These included genes associated with lipid biosynthesis or metabolism (lptA, faoA), phosphate uptake (pstB), and two-component regulators (amgRS, PA2797-PA2798) and a gene of unknown function (PA0392). Deletion mutants lacking these showed enhanced panaminoglycoside susceptibility that was reversed by the cloned genes, confirming their contribution to intrinsic panaminoglycoside resistance. None of these mutants showed increased aminoglycoside permeation of the cell envelope, indicating that increased susceptibility was not related to enhanced aminoglycoside uptake owing to a reduced envelope barrier function. Several mutants (pstB, faoA, PA0392, amgR) did, however, show increased cytoplasmic membrane depolarization relative to wild type following gentamicin exposure, consistent with the membranes of these mutants being more prone to perturbation, likely by gentamicin-generated mistranslated polypeptides. Mutants lacking any two of these resistance genes in various combinations invariably showed increased aminoglycoside susceptibility relative to single-deletion mutants, confirming their independent contribution to resistance and highlighting the complexity of the intrinsic aminoglycoside resistome in P. aeruginosa. Deletion of these genes also compromised the high-level panaminoglycoside resistance of clinical isolates, emphasizing their important contribution to acquired resistance.
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Huang WY, Yeh CL, Lin JH, Yang JS, Ko TH, Lin YH. Development of fibroblast culture in three-dimensional activated carbon fiber-based scaffold for wound healing. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1465-1478. [PMID: 22415364 DOI: 10.1007/s10856-012-4608-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 02/28/2012] [Indexed: 05/31/2023]
Abstract
This work developed a novel bi-layer wound dressing composed of 3D activated carbon fibers that allows facilitates fibroblast cell growth and migration to a wound site for tissue reconstruction, and the gentamicin is incorporated into a poly(γ-glutamic acid)/gelatin membrane to prevent bacterial infection. In an in vitro, field emission scanning electron microscopy shows that rat skin fibroblasts appeared and spread on the surface of activated carbon fibers, and penetrated the interior and exterior of the 3D activated carbon fiber construct to a depth of roughly 200 μm. An in vivo analysis shows that fibroblast cells containing the proposed 3D scaffold had the potential of a biologically functionalized dressing to accelerate wound closure. Additionally, fibroblasts migrated to the wound site in a bi-layer wound dressing containing fibroblasts, enhancing fibronectin and type I collagen expression, resulting in faster skin regeneration than that achieved with a Tegaderm™ hydrocolloid dressing or gauze.
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Affiliation(s)
- Wen-Ying Huang
- Department of Applied Cosmetology and Graduate Institute of Cosmetic Science, Hungkuang University, Taichung, Taiwan
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Gillanders LJ, Elborn JS, Gilpin DF, Schneiders T, Tunney MM. The airway microbiome in cystic fibrosis: challenges for therapy. ACTA ACUST UNITED AC 2011. [DOI: 10.2217/thy.11.81] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Mechanisms of aminoglycoside ototoxicity and targets of hair cell protection. Int J Otolaryngol 2011; 2011:937861. [PMID: 22121370 PMCID: PMC3202092 DOI: 10.1155/2011/937861] [Citation(s) in RCA: 267] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 08/18/2011] [Indexed: 01/14/2023] Open
Abstract
Aminoglycosides are commonly prescribed antibiotics with deleterious side effects to the inner ear. Due to their popular application as a result of their potent antimicrobial activities, many efforts have been undertaken to prevent aminoglycoside ototoxicity. Over the years, understanding of the antimicrobial as well as ototoxic mechanisms of aminoglycosides has increased. These mechanisms are reviewed in regard to established and potential future targets of hair cell protection.
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Sublethal triclosan exposure decreases susceptibility to gentamicin and other aminoglycosides in Listeria monocytogenes. Antimicrob Agents Chemother 2011; 55:4064-71. [PMID: 21746948 DOI: 10.1128/aac.00460-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human food-borne pathogen Listeria monocytogenes is capable of persisting in food processing plants despite cleaning and sanitation and is likely exposed to sublethal biocide concentrations. This could potentially affect susceptibility of the bacterium to biocides and other antimicrobial agents. The purpose of the present study was to determine if sublethal biocide concentrations affected antibiotic susceptibility in L. monocytogenes. Exposure of L. monocytogenes strains EGD and N53-1 to sublethal concentrations of Incimaxx DES (containing peroxy acids and hydrogen peroxide) and Triquart Super (containing quaternary ammonium compound) in four consecutive cultures did not alter the frequency of antibiotic-tolerant isolates, as determined by plating on 2× the MIC for a range of antibiotics. Exposure of eight strains of L. monocytogenes to 1 and 4 μg/ml triclosan did not alter triclosan sensitivity. However, all eight strains became resistant to gentamicin (up to 16-fold increase in MIC) after exposure to sublethal triclosan concentrations. Gentamicin-resistant isolates of strains N53-1 and 4446 were also resistant to other aminoglycosides, such as kanamycin, streptomycin, and tobramycin. Gentamicin resistance remained at a high level also after five subcultures without triclosan or gentamicin. Aminoglycoside resistance can be caused by mutations in the target site, the 16S rRNA gene. However, such mutations were not detected in the N53-1-resistant isolates. A combination of gentamicin and ampicillin is commonly used in listeriosis treatment. The triclosan-induced resistance is, hence, of great concern. Further investigations are needed to determine the molecular mechanisms underlying the effect of triclosan.
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Abstract
It is generally assumed that antibiotics and resistance determinants are the task forces of a biological warfare in which each resistance determinant counteracts the activity of a specific antibiotic. According to this view, antibiotic resistance might be considered as a specific response to an injury, not necessarily linked to bacterial metabolism, except for the burden that the acquisition of resistance might impose on the bacteria (fitness costs). Nevertheless, it is known that changes in bacterial metabolism, such as those associated with dormancy or biofilm formation, modulate bacterial susceptibility to antibiotics (phenotypic resistance), indicating that there exists a linkage between bacterial metabolism and antibiotic resistance. The analyses of the intrinsic resistomes of bacterial pathogens also demonstrate that the building up of intrinsic resistance requires the concerted action of many elements, several of which play a relevant role in the bacterial metabolism. In this article, we will review the current knowledge on the linkage between bacterial metabolism and antibiotic resistance and will discuss the role of global metabolic regulators such as Crc in bacterial susceptibility to antibiotics. Given that growing into the human host requires a metabolic adaptation, we will discuss whether this adaptation might trigger resistance even in the absence of selective pressure by antibiotics.
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Affiliation(s)
- José L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Madrid, Spain.
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Lin YH, Lin JH, Peng SF, Yeh CL, Chen WC, Chang TL, Liu MJ, Lai CH. Multifunctional gentamicin supplementation of poly(γ-glutamic acid)-based hydrogels for wound dressing application. J Appl Polym Sci 2010. [DOI: 10.1002/app.33249] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Abstract
Aminoglycosides have been an essential component of the armamentarium in the treatment of life-threatening infections. Unfortunately, their efficacy has been reduced by the surge and dissemination of resistance. In some cases the levels of resistance reached the point that rendered them virtually useless. Among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevalent in the clinical setting. Aminoglycoside modifying enzymes catalyze the modification at different -OH or -NH₂ groups of the 2-deoxystreptamine nucleus or the sugar moieties and can be nucleotidyltransferases, phosphotransferases, or acetyltransferases. The number of aminoglycoside modifying enzymes identified to date as well as the genetic environments where the coding genes are located is impressive and there is virtually no bacteria that is unable to support enzymatic resistance to aminoglycosides. Aside from the development of new aminoglycosides refractory to as many as possible modifying enzymes there are currently two main strategies being pursued to overcome the action of aminoglycoside modifying enzymes. Their successful development would extend the useful life of existing antibiotics that have proven effective in the treatment of infections. These strategies consist of the development of inhibitors of the enzymatic action or of the expression of the modifying enzymes.
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