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da Rosa EEB, Kremer FS. The mobilome landscape of biocide-resistance in Brazilian ESKAPE isolates. Braz J Microbiol 2024:10.1007/s42770-024-01450-7. [PMID: 39028534 DOI: 10.1007/s42770-024-01450-7] [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: 05/13/2024] [Accepted: 07/03/2024] [Indexed: 07/20/2024] Open
Abstract
The increasing frequency of antibiotic-resistant bacteria is a constant threat to global human health. Therefore, the pathogens of the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Enterobacter spp.) are among the most relevant causes of hospital infections responsible for millions of deaths every year. However, little has been explored about the danger of microorganisms resistant to biocides such as antiseptics and disinfectants. Widely used in domestic, industrial, and hospital environments, these substances reach the environment and can cause selective pressure for resistance genes and induce cross-resistance to antibiotics, further aggravating the problem. Therefore, it is necessary to use innovative and efficient strategies to monitor the spread of genes related to resistance to biocides. Whole genome sequencing and bioinformatics analysis aiming to search for sequences encoding resistance mechanisms are essential to help monitor and combat these pathogens. Thus, this work describes the construction of a bioinformatics tool that integrates different databases to identify gene sequences that may confer some resistance advantage about biocides. Furthermore, the tool analyzed all the genomes of Brazilian ESKAPE isolates deposited at NCBI and found a series of different genes related to resistance to benzalkonium chloride, chlorhexidine, and triclosan, which were the focus of this work. As a result, the presence of resistance genes was identified in different types of biological samples, environments, and hosts. Regarding mobile genetic elements (MGEs), around 52% of isolates containing genes related to resistance to these compounds had their genes identified in plasmids, and 48.7% in prophages. These data show that resistance to biocides can be a silent, underestimated danger spreading across different environments and, therefore, requires greater attention.
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Affiliation(s)
- Elias Eduardo Barbosa da Rosa
- Laboratório de Bioinformática (Omixlab), Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Rio Grande Do Sul, Brazil
| | - Frederico Schmitt Kremer
- Laboratório de Bioinformática (Omixlab), Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Rio Grande Do Sul, Brazil.
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2
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Pereira AP, Antunes P, Peixe L, Freitas AR, Novais C. Current insights into the effects of cationic biocides exposure on Enterococcus spp. Front Microbiol 2024; 15:1392018. [PMID: 39006755 PMCID: PMC11242571 DOI: 10.3389/fmicb.2024.1392018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 06/04/2024] [Indexed: 07/16/2024] Open
Abstract
Cationic biocides (CBs), such as quaternary ammonium compounds and biguanides, are critical for controlling the spread of bacterial pathogens like Enterococcus spp., a leading cause of multidrug-resistant healthcare-associated infections. The widespread use of CBs in recent decades has prompted concerns about the potential emergence of Enterococcus spp. populations exhibiting resistance to both biocides and antibiotics. Such concerns arise from their frequent exposure to subinhibitory concentrations of CBs in clinical, food chain and diverse environmental settings. This comprehensive narrative review aimed to explore the complexity of the Enterococcus' response to CBs and of their possible evolution toward resistance. To that end, CBs' activity against diverse Enterococcus spp. collections, the prevalence and roles of genes associated with decreased susceptibility to CBs, and the potential for co- and cross-resistance between CBs and antibiotics are reviewed. Significant methodological and knowledge gaps are identified, highlighting areas that future studies should address to enhance our comprehension of the impact of exposure to CBs on Enterococcus spp. populations' epidemiology. This knowledge is essential for developing effective One Health strategies that ensure the continued efficacy of these critical agents in safeguarding Public Health.
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Affiliation(s)
- Ana P Pereira
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Patrícia Antunes
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal
| | - Luísa Peixe
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Ana R Freitas
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
- 1H-TOXRUN, One Health Toxicology Research Unit, University Institute of Health Sciences, CESPU CRL, Gandra, Portugal
| | - Carla Novais
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
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3
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George NL, Bennett EC, Orlando BJ. Guarding the walls: the multifaceted roles of Bce modules in cell envelope stress sensing and antimicrobial resistance. J Bacteriol 2024:e0012324. [PMID: 38869304 DOI: 10.1128/jb.00123-24] [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: 06/14/2024] Open
Abstract
Bacteria have developed diverse strategies for defending their cell envelopes from external threats. In Firmicutes, one widespread strategy is to use Bce modules-membrane protein complexes that unite a peptide-detoxifying ABC transporter with a stress response coordinating two-component system. These modules provide specific, front-line defense for a wide variety of antimicrobial peptides and small molecule antibiotics as well as coordinate responses for heat, acid, and oxidative stress. Because of these abilities, Bce modules play important roles in virulence and the development of antibiotic resistance in a variety of pathogens, including Staphylococcus, Streptococcus, and Enterococcus species. Despite their importance, Bce modules are still poorly understood, with scattered functional data in only a small number of species. In this review, we will discuss Bce module structure in light of recent cryo-electron microscopy structures of the B. subtilis BceABRS module and explore the common threads and variations-on-a-theme in Bce module mechanisms across species. We also highlight the many remaining questions about Bce module function. Understanding these multifunctional membrane complexes will enhance our understanding of bacterial stress sensing and may point toward new therapeutic targets for highly resistant pathogens.
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Affiliation(s)
- Natasha L George
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing, Michigan, USA
| | - Ellen C Bennett
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology, Genetics, and Immunology, Michigan State University, East Lansing, Michigan, USA
| | - Benjamin J Orlando
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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Zhang J, Xu Z, Chu W, Ju F, Jin W, Li P, Xiao R. Residual chlorine persistently changes antibiotic resistance gene composition and increases the risk of antibiotic resistance in sewer systems. WATER RESEARCH 2023; 245:120635. [PMID: 37738943 DOI: 10.1016/j.watres.2023.120635] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/24/2023]
Abstract
During the COVID-19 pandemic, excessive amounts of disinfectants and their transformation products entered sewer systems worldwide, which was an extremely rare occurrence before. The stress of residual chlorine and disinfection by-products is not only likely to promote the spread of antibiotic resistance genes (ARGs), but also leads to the enrichment of chlorine-resistant bacteria that may also be resistant to antibiotics. Therefore, the potential impact of such discharge on ARG composition should be studied and the health risks should be assessed. Thus, this study combined high-throughput 16S rRNA gene amplicon sequencing and metagenomic analysis with long-term batch tests that involved two stages of stress and recovery to comprehensively evaluate the impact of residual chlorine on the microbial community and ARG compositions in sewer systems. The tests demonstrated that the disturbance of the microbial community structure by residual chlorine was reversible, but the change in ARG composition was persistent. This study found that vertical propagation and horizontal gene transfer jointly drove ARG composition succession in the biofilm, while the driving force was mainly horizontal gene transfer in the sediment. In this process, the biocide resistance gene (BRG) subtype chtR played an important role in promoting co-selection with ARGs through plasmids and integrative and conjugative elements. Moreover, it was further shown that the addition of sodium hypochlorite increased the risk of ARGs to human health, even after discontinuation of dosing, signifying that the impact was persistent. In general, this study strengthens the co-selection theory of ARGs and BRGs, and calls for improved disinfection strategies and more environmentally friendly disinfectants.
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Affiliation(s)
- Jingyi Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Zuxin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, Zhejiang 310030, China
| | - Wei Jin
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Peng Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; College of Resources and Environmental Engineering, Shandong Agriculture and Engineering University, Jinan, Shandong 250100, China
| | - Rong Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Chegene Lorestani R, Shojaeian A, Rostamian M. Phenotypic, genotypic, and metabolic resistance mechanisms of ESKAPE bacteria to chemical disinfectants: a systematic review and meta-analysis. Expert Rev Anti Infect Ther 2023; 21:1097-1123. [PMID: 37674347 DOI: 10.1080/14787210.2023.2256975] [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: 12/31/2022] [Revised: 07/31/2023] [Accepted: 09/01/2023] [Indexed: 09/08/2023]
Abstract
BACKGROUND The presence of resistant ESKAPE pathogens to antimicrobials including chemical disinfectants (ChDs) is a serious threat to public health worldwide. In the present study, we systematically reviewed published reports on mechanisms beyond ChD resistance of ESKAPE bacteria. RESEARCH DESIGN AND METHODS Several databases without date limitations were searched. Studies focused on the ChD resistance/tolerance mechanisms of ESKAPE bacteria were included. Meta-analysis was done to assess the frequency of tolerance and genes in ESKAPE clinical isolates. By screening of initial 6733 records, finally, 41 studies were included. RESULTS The overall tolerance to at least one ChD was 48.6%. Pseudomonas aeruginosa and Acinetobacter baumannii were highly ChD-resistant. In several studies, phenotypic changes including changes in general morphology, pump function, cell surface, and membrane, as well as metabolic changes were observed after ChD addition. The resistance gene frequency was 70.2% for norfloxacin efflux pump genes, 40.6% for qac major facilitator superfamily genes, and 22.2% for qac small multidrug resistance genes. CONCLUSION We systematically reviewed the effect of various mechanisms in the resistance process of ESKAPE bacteria to ChDs. However, except for the impact of genes, the numbers of studies investigating other mechanisms were very limited, demanding carrying out more studies in this field.
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Affiliation(s)
- Roya Chegene Lorestani
- Infectious Diseases Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ali Shojaeian
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mosayeb Rostamian
- Infectious Diseases Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
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6
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Leigh RJ, McKenna C, McWade R, Lynch B, Walsh F. Comparative genomics and pangenomics of vancomycin-resistant and susceptible Enterococcus faecium from Irish hospitals. J Med Microbiol 2022; 71. [DOI: 10.1099/jmm.0.001590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction.
Enterococcus faecium
has emerged as an important nosocomial pathogen, which is increasingly difficult to treat due to the genetic acquisition of vancomycin resistance. Ireland has a recalcitrant vancomycin-resistant bloodstream infection rate compared to other developed countries.
Hypothesis/Gap statement. Vancomycin resistance rates persist amongst
E. faecium
isolates from Irish hospitals. The evolutionary genomics governing these trends have not been fully elucidated.
Methodology. A set of 28 vancomycin-resistant isolates was sequenced to construct a dataset alongside 61 other publicly available Irish genomes. This dataset was extensively analysed using in silico methodologies (comparative genomics, pangenomics, phylogenetics, genotypics and comparative functional analyses) to uncover distinct evolutionary, coevolutionary and clinically relevant population trends.
Results. These results suggest that a stable (in terms of genome size, GC% and number of genes), yet genetically diverse population (in terms of gene content) of
E. faecium
persists in Ireland with acquired resistance arising via plasmid acquisition (vanA) or, to a lesser extent, chromosomal recombination (vanB). Population analysis revealed five clusters with one cluster partitioned into four clades which transcend isolation dates. Pangenomic and recombination analyses revealed an open (whole genome and chromosomal specific) pangenome illustrating a rampant evolutionary pattern. Comparative resistomics and virulomics uncovered distinct chromosomal and mobilomal propensity for multidrug resistance, widespread chromosomal point-mutation-mediated resistance and chromosomally harboured arsenals of virulence factors. Interestingly, a potential difference in biofilm formation strategies was highlighted by coevolutionary analysis, suggesting differential biofilm genotypes between vanA and vanB isolates.
Conclusions. These results highlight the evolutionary history of Irish
E. faecium
isolates and may provide insight into underlying infection dynamics in a clinical setting. Due to the apparent ease of vancomycin resistance acquisition over time, susceptible
E. faecium
should be concurrently reduced in Irish hospitals to mitigate potential resistant infections.
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Affiliation(s)
- Robert J. Leigh
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
| | - Chloe McKenna
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
| | - Robert McWade
- Department of Microbiology, Mater Misericordiae University Hospital, Eccles St., Dublin 7, D07 R2WY, Ireland
| | - Breda Lynch
- Department of Microbiology, Mater Misericordiae University Hospital, Eccles St., Dublin 7, D07 R2WY, Ireland
| | - Fiona Walsh
- Department of Biology, Maynooth University, Mariavilla, Maynooth, Co. Kildare, Ireland
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7
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Pereira AP, Antunes P, Willems R, Corander J, Coque TM, Peixe L, Freitas AR, Novais C. Evolution of Chlorhexidine Susceptibility and of the EfrEF Operon among Enterococcus faecalis from Diverse Environments, Clones, and Time Spans. Microbiol Spectr 2022; 10:e0117622. [PMID: 35862993 PMCID: PMC9430118 DOI: 10.1128/spectrum.01176-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/17/2022] [Indexed: 11/20/2022] Open
Abstract
Chlorhexidine (CHX) is widely used to control the spread of pathogens (e.g., human/animal clinical settings, ambulatory care, food industry). Enterococcus faecalis, a major nosocomial pathogen, is broadly distributed in diverse hosts and environments facilitating its exposure to CHX over the years. Nevertheless, CHX activity against E. faecalis is understudied. Our goal was to assess CHX activity and the variability of ChlR-EfrEF proteins (associated with CHX tolerance) among 673 field isolates and 1,784 E. faecalis genomes from the PATRIC database from different sources, time spans, clonal lineages, and antibiotic-resistance profiles. The CHX MIC (MICCHX) and minimum bactericidal concentration (MBCCHX) against E. faecalis presented normal distributions (0.5 to 64 mg/L). However, more CHX-tolerant isolates were detected in the food chain and recent human infections, suggesting an adaptability of E. faecalis populations in settings where CHX is heavily used. Heterogeneity in ChlR-EfrEF sequences was identified, with isolates harboring incomplete ChlR-EfrEF proteins, particularly the EfrE identified in the ST40 clonal lineage, showing low MICCHX (≤1mg/L). Distinct ST40-E. faecalis subpopulations carrying truncated and nontruncated EfrE were detected, with the former being predominant in human isolates. This study provides a new insight about CHX susceptibility and ChlR-EfrEF variability within diverse E. faecalis populations. The MICCHX/MBCCHX of more tolerant E. faecalis (MICCHX = 8 mg/L; MBCCHX = 64 mg/L) remain lower than in-use concentrations of CHX (≥500 mg/L). However, increased CHX use, combined with concentration gradients occurring in diverse environments, potentially selecting multidrug-resistant strains with different CHX susceptibilities, signals the importance of monitoring the trends of E. faecalis CHX tolerance within a One Health approach. IMPORTANCE Chlorhexidine (CHX) is a disinfectant and antiseptic used since the 1950s and included in the World Health Organization's list of essential medicines. It has been widely applied in hospitals, the community, the food industry, animal husbandry and pets. CHX tolerance in Enterococcus faecalis, a ubiquitous bacterium and one of the leading causes of human hospital-acquired infections, remains underexplored. Our study provides novel and comprehensive insights about CHX susceptibility within the E. faecalis population structure context, revealing more CHX-tolerant subpopulations from the food chain and recent human infections. We further show a detailed analysis of the genetic diversity of the efrEF operon (previously associated with E. faecalis CHX tolerance) and its correlation with CHX phenotypes. The recent strains with a higher tolerance to CHX and the multiple sources where bacteria are exposed to this biocide alert us to the need for the continuous monitoring of E. faecalis adaptation toward CHX tolerance within a One Health approach.
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Affiliation(s)
- Ana P. Pereira
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Patrícia Antunes
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal
| | - Rob Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jukka Corander
- Department of Biostatistics, Faculty of Medicine, University of Oslo, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, United Kingdom
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - Teresa M. Coque
- Servicio de Microbiologia, Hospital Universitario Ramón y Cajal, Madrid, Spain
- Centro de Investigación Biomédica en Enfermedades Infecciosas (CIBER-EII), Madrid, Spain
| | - Luísa Peixe
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Ana R. Freitas
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
- TOXRUN, Toxicology Research Unit, University Institute of Health Sciences, CESPU, CRL, Gandra, Portugal
| | - Carla Novais
- UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
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Hill DL, Pinger C, Noland EL, Morton K, Hunt AMA, Pensler E, Cantu S, Attar PS, Siddiqi A. A novel activated-zinc antiseptic solution effective against MRSA and Pseudomonas aeruginosa: a pig model. J Wound Care 2022; 31:S41-S50. [PMID: 35797249 DOI: 10.12968/jowc.2022.31.sup7.s41] [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: 11/11/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate the antimicrobial efficacy of a novel activated zinc solution against meticillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa after one hour, and to evaluate any untoward effect of the solution on local wound tissue at 24 hours after solution exposure in a pig wound model. METHOD A pathogen-free, commercially raised, Yorkshire-cross female pig was acquired 12 days prior to the procedure. Within one week prior to the procedure, a small loopful of test bacteria, Pseudomonas aeruginosa (pig-isolate) and MRSA (ATCC-6538), were streaked and cultured on a non-selective agar. Full-thickness wounds (n=24) were created and evenly divided into three groups: control wounds (exposed to bacteria but untreated, n=8); wounds treated with Compound 1 (n=8), and wounds treated with Compound 2 (n=8). All wounds were dressed and monitored for one hour and 24 hours. RESULTS After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable total bacteria of 2.8 log colony forming units (CFUs) and 3.5 logCFUs, respectively. After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable MRSA of 2.3 logCFUs and 1.6 logCFUs, respectively (p=0.009). After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable Pseudomonas aeruginosa of 0.3 logCFUs and 0.0 logCFUs, respectively (p=0.000). After 24 hours of exposure to Compound 1 and Compound 2, there was no statistically significant increased necrosis (p=0.12, p=0.31, respectively) or neutrophilic infiltrate (Compound 2, p=0.12) when compared with control wounds. CONCLUSION The novel activated-zinc compound used in this study demonstrated a 99.5-99.9% reduction in total bacteria, a 99.9-99.98% reduction in MRSA, and 100% eradication of Pseudomonas aeruginosa one hour after exposure. This novel solution may provide another significant tool to treat and/or prevent wound infections.
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Affiliation(s)
- Derek L Hill
- Michigan State University College of Osteopathic Medicine Hill Orthopedics, US
| | - Cody Pinger
- Institute for Quantitative Health Science and Engineering Michigan State University, US
| | - Erica L Noland
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, US
| | - Kevin Morton
- Ascension Macomb-Oakland, Michigan State University College of Osteopathic Medicine, US
| | | | | | | | | | - Ahmed Siddiqi
- Cleveland Clinic Foundation, Orthopaedic and Rheumatologic Institute, Cleveland, OH, US
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9
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Enterococcus Virulence and Resistant Traits Associated with Its Permanence in the Hospital Environment. Antibiotics (Basel) 2022; 11:antibiotics11070857. [PMID: 35884110 PMCID: PMC9311936 DOI: 10.3390/antibiotics11070857] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
Enterococcus are opportunistic pathogens that have been gaining importance in the clinical setting, especially in terms of hospital-acquired infections. This problem has mainly been associated with the fact that these bacteria are able to present intrinsic and extrinsic resistance to different classes of antibiotics, with a great deal of importance being attributed to vancomycin-resistant enterococci. However, other aspects, such as the expression of different virulence factors including biofilm-forming ability, and its capacity of trading genetic information, makes this bacterial genus more capable of surviving harsh environmental conditions. All these characteristics, associated with some reports of decreased susceptibility to some biocides, all described in this literary review, allow enterococci to present a longer survival ability in the hospital environment, consequently giving them more opportunities to disseminate in these settings and be responsible for difficult-to-treat infections.
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10
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Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
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11
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Abstract
Serious infections owing to vancomycin-resistant enterococci have historically proven to be difficult clinical cases, requiring combination therapy and management of treatment-related toxicity. Despite the introduction of new antibiotics with activity against vancomycin-resistant enterococci to the therapeutic armamentarium, significant challenges remain. An understanding of the factors driving the emergence of resistance in vancomycin-resistant enterococci, the dynamics of gastrointestinal colonization and microbiota-mediated colonization resistance, and the mechanisms of resistance to the currently available therapeutics will permit clinicians to be better prepared to tackle these challenging hospital-associated pathogens.
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Affiliation(s)
- William R Miller
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG)
| | - Barbara E Murray
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG); Department of Microbiology and Molecular Genetics, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA
| | - Louis B Rice
- Department of Internal Medicine, Brown University, 593 Eddy Street, Providence, RI 02903, USA
| | - Cesar A Arias
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas Health Science Center at Houston, McGovern Medical School, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics (CARMiG); Department of Microbiology and Molecular Genetics, 6431 Fannin St. MSB 2.112, Houston, TX 77030, USA; University of Texas Health Science Center at Houston, School of Public Health, Houston, TX, USA; Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogota, Colombia.
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12
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Quantifying acquisition and transmission of Enterococcus faecium using genomic surveillance. Nat Microbiol 2020; 6:103-111. [PMID: 33106672 PMCID: PMC7610418 DOI: 10.1038/s41564-020-00806-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 09/30/2020] [Indexed: 12/15/2022]
Abstract
Nosocomial acquisition and transmission of vancomycin-resistant Enterococcus faecium (VREfm) is the driver for E. faecium carriage in hospitalized patients, which, in turn, is a risk factor for invasive infection in immunocompromised patients. In the present study, we provide a comprehensive picture of E. faecium transmission in an entire sampled patient population using a sequence-driven approach. We prospectively identified and followed 149 haematology patients admitted to a hospital in England for 6 months. Patient stools (n = 376) and environmental swabs (n = 922) were taken at intervals and cultured for E. faecium. We sequenced 1,560 isolates (1,001 stool, 559 environment) and focused our genomic analyses on 1,477 isolates (95%) in the hospital-adapted clade A1. Of 101 patients who provided two or more stool samples, 40 (40%) developed E. faecium carriage after admission based on culture, compared with 64 patients (63%) based on genomic analysis (73% VREfm). Half of 922 environmental swabs (447, 48%) were positive for VREfm. Network analysis showed that, of 111 patients positive for the A1 clade, 67 had strong epidemiological and genomic links with at least one other patient and/or their direct environment, supporting nosocomial transmission. Six patients (3.4%) developed an invasive E. faecium infection from their own gut-colonizing strain, which was preceded by nosocomial acquisition of the infecting isolate in half of these. Two informatics approaches (subtype categorization to define phylogenetic clusters and the development of an SNP cut-off for transmission) were central to our analyses, both of which will inform the future translation of E. faecium sequencing into routine outbreak detection and investigation. In conclusion, we showed that carriage and environmental contamination by the hospital-adapted E. faecium lineage were hyperendemic in our study population and that improved infection control measures will be needed to reduce hospital acquisition rates.
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13
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Addressing the challenges in antisepsis: focus on povidone iodine. Int J Antimicrob Agents 2020; 56:106064. [DOI: 10.1016/j.ijantimicag.2020.106064] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/21/2020] [Accepted: 06/21/2020] [Indexed: 12/15/2022]
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14
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Roedel A, Dieckmann R, Makarewicz O, Hartung A, Noll M, Pletz MW, Dahouk SA, Vincze S. Evaluation of a Newly Developed Vacuum Dried Microtiter Plate for Rapid Biocide Susceptibility Testing of Clinical Enterococcus Faecium Isolates. Microorganisms 2020; 8:E551. [PMID: 32290364 PMCID: PMC7232460 DOI: 10.3390/microorganisms8040551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/27/2022] Open
Abstract
We investigated the suitability of a newly developed biocide susceptibility test system based on microtiter plates containing vacuum dried biocides as a fast and reliable screening method. The evaluated substances included the cationic biocides benzalkonium chloride (BAC), chlorhexidine dihydrochloride (CHX), cetylpyridinium chloride, didecyldimethylammonium chloride, and octenidine dihydrochloride. Testing a selection of Escherichia coli and enterococci, the biocide microtiter plates provided results comparable to those obtained from broth microdilution according to ISO 20776-1. Broad MIC ranges allowed for testing gram-positive and gram-negative species with the same plate design. In the second part of our study, we applied the established method to analyze the susceptibility of 90 clinical Enterococcus faecium isolates from a German university hospital, as previous studies have indicated a link between reduced susceptibility to substances such as CHX and BAC and vancomycin resistance. We therefore determined MIC and minimum bactericidal concentrations (MBC) for 48 non-clonal vancomycin susceptible and 42 non-clonal vancomycin resistant isolates, but MIC95 and MBC95 were quite similar in both groups. Our easy to handle and ready to use test system enables the routine surveillance of bacterial tolerance towards disinfectants in hospitals. As a result, hygiene measures can be adapted and nosocomial infections controlled despite increasing prevalence of antibiotic-resistant bacteria.
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Affiliation(s)
- Alice Roedel
- German Federal Institute for Risk Assessment, Department of Biological Safety, 10589 Berlin, Germany
| | - Ralf Dieckmann
- German Federal Institute for Risk Assessment, Department of Biological Safety, 10589 Berlin, Germany
| | - Oliwia Makarewicz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, 07747 Jena, Germany
- Research Campus Infectognostics, 07743 Jena, Germany
| | - Anita Hartung
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, 07747 Jena, Germany
- Research Campus Infectognostics, 07743 Jena, Germany
| | - Matthias Noll
- Institute for Bioanalysis, University of Applied Sciences and Arts, 96450 Coburg, Germany
| | - Mathias W Pletz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, 07747 Jena, Germany
- Research Campus Infectognostics, 07743 Jena, Germany
| | - Sascha Al Dahouk
- German Federal Institute for Risk Assessment, Department of Biological Safety, 10589 Berlin, Germany
- Department of Internal Medicine, RWTH Aachen University Hospital, 52074 Aachen, Germany
| | - Szilvia Vincze
- German Federal Institute for Risk Assessment, Department of Biological Safety, 10589 Berlin, Germany
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15
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2CS-CHX T Operon Signature of Chlorhexidine Tolerance among Enterococcus faecium Isolates. Appl Environ Microbiol 2019; 85:AEM.01589-19. [PMID: 31562170 DOI: 10.1128/aem.01589-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/20/2019] [Indexed: 11/20/2022] Open
Abstract
Chlorhexidine (CHX) is a broad-spectrum antiseptic widely used in community and clinical contexts for many years that has recently acquired higher relevance in nosocomial infection control worldwide. Despite this, CHX tolerance among Enterococcus faecium bacteria, representing one of the leading agents causing nosocomial infections, has been poorly understood. This study provides new phenotypic and molecular data for better identification of CHX-tolerant E. faecium subpopulations in community and clinical contexts. The chlorhexidine MIC (MICCHX) distribution of 106 E. faecium isolates suggested the occurrence of tolerant subpopulations in diverse sources (human, animal, food, environment) and phylogenomic backgrounds (clades A1/A2/B), with predominance in clade A1. They carried a specific variant of the 2CS-CHXT operon, identified here. It encodes glucose and amino acid-polyamine-organocation family transporters, besides the DNA-binding response regulator ChtR, with a P102H mutation previously described only in CHX-tolerant clade A1 E. faecium, and the ChtS sensor. 2CS-CHXT seems to be associated with three regulons modulating diverse bacterial biological functions. Combined data from normal MIC distribution and 2CS-CHXT operon characterization support a tentative epidemiological cutoff (ECOFF) of 8 mg/liter to CHX, which is useful to detect tolerant E. faecium populations in future surveillance studies. The spread of tolerant E. faecium in diverse epidemiological backgrounds calls for the prudent use of CHX in multiple contexts.IMPORTANCE Chlorhexidine is one of the substances included in the World Health Organization's list of essential medicines, which comprises the safest and most effective medicines needed in global health systems. Although it has been widely applied as a disinfectant and antiseptic in health care (skin, hands, mouthwashes, eye drops) since the 1950s, its use in hospitals to prevent nosocomial infections has increased worldwide in recent years. Here, we provide a comprehensive study on chlorhexidine tolerance among strains of Enterococcus faecium, one of the leading nosocomial agents worldwide, and identify a novel 2CS-CHXT operon as a signature of tolerant strains occurring in diverse phylogenomic groups. Our data allowed for the proposal of a tentative epidemiological cutoff of 8 mg/liter, which is useful to detect tolerant E. faecium populations in surveillance studies in community and clinical contexts. The prediction of 2CS-CHXT regulons will also facilitate the design of future experimental studies to better uncover chlorhexidine tolerance among E. faecium bacteria.
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16
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Pidot SJ, Gao W, Buultjens AH, Monk IR, Guerillot R, Carter GP, Lee JYH, Lam MMC, Grayson ML, Ballard SA, Mahony AA, Grabsch EA, Kotsanas D, Korman TM, Coombs GW, Robinson JO, Gonçalves da Silva A, Seemann T, Howden BP, Johnson PDR, Stinear TP. Increasing tolerance of hospital Enterococcus faecium to handwash alcohols. Sci Transl Med 2019; 10:10/452/eaar6115. [PMID: 30068573 DOI: 10.1126/scitranslmed.aar6115] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 02/10/2018] [Accepted: 04/03/2018] [Indexed: 11/03/2022]
Abstract
Alcohol-based disinfectants and particularly hand rubs are a key way to control hospital infections worldwide. Such disinfectants restrict transmission of pathogens, such as multidrug-resistant Staphylococcus aureus and Enterococcus faecium Despite this success, health care infections caused by E. faecium are increasing. We tested alcohol tolerance of 139 hospital isolates of E. faecium obtained between 1997 and 2015 and found that E. faecium isolates after 2010 were 10-fold more tolerant to killing by alcohol than were older isolates. Using a mouse gut colonization model of E. faecium transmission, we showed that alcohol-tolerant E. faecium resisted standard 70% isopropanol surface disinfection, resulting in greater mouse gut colonization compared to alcohol-sensitive E. faecium We next looked for bacterial genomic signatures of adaptation. Alcohol-tolerant E. faecium accumulated mutations in genes involved in carbohydrate uptake and metabolism. Mutagenesis confirmed the roles of these genes in the tolerance of E. faecium to isopropanol. These findings suggest that bacterial adaptation is complicating infection control recommendations, necessitating additional procedures to prevent E. faecium from spreading in hospital settings.
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Affiliation(s)
- Sacha J Pidot
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Wei Gao
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Andrew H Buultjens
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Ian R Monk
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Romain Guerillot
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Glen P Carter
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Jean Y H Lee
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Margaret M C Lam
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - M Lindsay Grayson
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia.,Department of Epidemiology and Preventive Medicine, Monash University, Victoria 3800, Australia
| | - Susan A Ballard
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Andrew A Mahony
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Elizabeth A Grabsch
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia
| | - Despina Kotsanas
- Monash Infectious Diseases, Monash Health, Clayton, Victoria 3168, Australia
| | - Tony M Korman
- Monash Infectious Diseases, Monash Health, Clayton, Victoria 3168, Australia
| | - Geoffrey W Coombs
- Antimicrobial Resistance and Infectious Diseases Research Laboratory, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.,Department of Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia 6150, Australia
| | - J Owen Robinson
- Antimicrobial Resistance and Infectious Diseases Research Laboratory, School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.,Department of Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia 6150, Australia
| | - Anders Gonçalves da Silva
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Torsten Seemann
- Melbourne Bioinformatics, University of Melbourne, Carlton, Victoria 3053, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia.,Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia.,Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia
| | - Paul D R Johnson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia. .,Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia.,Department of Medicine, University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Timothy P Stinear
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Victoria 3010, Australia.
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17
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Abstract
Vancomycin-resistant Enterococcus faecium (VREfm) is a globally significant public health threat and was listed on the World Health Organization's 2017 list of high-priority pathogens for which new treatments are urgently needed. Treatment options for invasive VREfm infections are very limited, and outcomes are often poor. Whole-genome sequencing is providing important new insights into VREfm evolution, drug resistance and hospital adaptation, and is increasingly being used to track VREfm transmission within hospitals to detect outbreaks and inform infection control practices. This mini-review provides an overview of recent data on the use of genomics to understand and respond to the global problem of VREfm.
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Affiliation(s)
- Claire Gorrie
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Charlie Higgs
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Glen Carter
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Timothy P Stinear
- Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Benjamin Howden
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.,Department of Infectious Diseases, Austin Health, Heidelberg, Australia.,Doherty Applied Microbial Genomics, Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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18
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Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
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19
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Fiore E, Van Tyne D, Gilmore MS. Pathogenicity of Enterococci. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0053-2018. [PMID: 31298205 PMCID: PMC6629438 DOI: 10.1128/microbiolspec.gpp3-0053-2018] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Indexed: 12/19/2022] Open
Abstract
Enterococci are unusually well adapted for survival and persistence in a variety of adverse environments, including on inanimate surfaces in the hospital environment and at sites of infection. This intrinsic ruggedness undoubtedly played a role in providing opportunities for enterococci to interact with other overtly drug-resistant microbes and acquire additional resistances on mobile elements. The rapid rise of antimicrobial resistance among hospital-adapted enterococci has rendered hospital-acquired infections a leading therapeutic challenge. With about a quarter of a genome of additional DNA conveyed by mobile elements, there are undoubtedly many more properties that have been acquired that help enterococci persist and spread in the hospital setting and cause diseases that have yet to be defined. Much remains to be learned about these ancient and rugged microbes, particularly in the area of pathogenic mechanisms involved with human diseases.
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Affiliation(s)
- Elizabeth Fiore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Daria Van Tyne
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Michael S Gilmore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
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20
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Spontaneously Arising Streptococcus mutans Variants with Reduced Susceptibility to Chlorhexidine Display Genetic Defects and Diminished Fitness. Antimicrob Agents Chemother 2019; 63:AAC.00161-19. [PMID: 31036688 DOI: 10.1128/aac.00161-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/20/2019] [Indexed: 01/10/2023] Open
Abstract
Chlorhexidine (CHX) has been used to control dental caries caused by acid-tolerant bacteria such as Streptococcus mutans since the 1970s. Repeat CHX exposure for other bacterial species results in the development of variants with reduced susceptibility that also become more resistant to other antimicrobials. It has not been tested if such variants arise when streptococci are exposed to CHX. Here, we passaged S. mutans in increasing concentrations of CHX and isolated spontaneously arising reduced susceptibility variants (RSVs) from separate lineages that have MICs that are up to 3-fold greater than the parental strain. The RSVs have increased growth rates at neutral pH and under acidic conditions in the presence of CHX but accumulate less biomass in biofilms. RSVs display higher MICs for daptomycin and clindamycin but increased sensitivity to dental-relevant antimicrobials triclosan and sodium fluoride. Plate-based assays for competition with health-associated oral streptococci revealed decreased bacteriocin production by the RSVs, increased sensitivity to hydrogen peroxide, and diminished competitive fitness in a human-derived ex vivo biofilm consortium. Whole-genome sequencing identified common single nucleotide polymorphisms (SNPs) within a diacylglycerol kinase homolog and a glycolipid synthesis enzyme, which could alter the accumulation of lipoteichoic acids and other envelope constituents, as well as a variety of mutations in other genes. Collectively, these findings confirm that S. mutans and likely other streptococci can develop tolerance to CHX but that increased tolerance comes at a fitness cost, such that CHX-induced variants that spontaneously arise in the human oral cavity may not persist.
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21
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Zhou L, Wang L, Tian P, Bao T, Li L, Zhao X. The LiaFSR and BsrXRS Systems Contribute to Bile Salt Resistance in Enterococcus faecium Isolates. Front Microbiol 2019; 10:1048. [PMID: 31134041 PMCID: PMC6522849 DOI: 10.3389/fmicb.2019.01048] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022] Open
Abstract
Two-component systems (TCSs) are dominant regulating components in bacteria for responding to environmental stimuli. However, little information is available on how TCSs in Enterococcus faecium respond to bile salts - an important environmental stimulus for intestinal bacteria. In this study, the gene expression of 2 TCSs, BsrXRS and LiaFSR, was positively correlated with survival rates of different E. faecium isolates during exposure to ox gall. Moreover, gene disruptions of bsrR, bsrS, liaS, and liaR significantly reduced the survival rates of E. faecium in the presence of ox gall. Finally, EMSA results indicated that BsrR functioned as a transcription regulator for expression of its own gene as well as lipoate-protein ligase A (lplA). Additional 27 potential target genes by BsrR were revealed through in silico analyses. These findings suggest that BsrXRS and LiaFSR systems play important roles in bile salt resistance in E. faecium.
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Affiliation(s)
- Luoxiong Zhou
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Lihong Wang
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Ping Tian
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Tingting Bao
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Lianbin Li
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Xin Zhao
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
- Department of Animal Science, McGill University, Montreal, QC, Canada
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22
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Abstract
The study of the genetics of enterococci has focused heavily on mobile genetic elements present in these organisms, the complex regulatory circuits used to control their mobility, and the antibiotic resistance genes they frequently carry. Recently, more focus has been placed on the regulation of genes involved in the virulence of the opportunistic pathogenic species Enterococcus faecalis and Enterococcus faecium. Little information is available concerning fundamental aspects of DNA replication, partition, and division; this article begins with a brief overview of what little is known about these issues, primarily by comparison with better-studied model organisms. A variety of transcriptional and posttranscriptional mechanisms of regulation of gene expression are then discussed, including a section on the genetics and regulation of vancomycin resistance in enterococci. The article then provides extensive coverage of the pheromone-responsive conjugation plasmids, including sections on regulation of the pheromone response, the conjugative apparatus, and replication and stable inheritance. The article then focuses on conjugative transposons, now referred to as integrated, conjugative elements, or ICEs, and concludes with several smaller sections covering emerging areas of interest concerning the enterococcal mobilome, including nonpheromone plasmids of particular interest, toxin-antitoxin systems, pathogenicity islands, bacteriophages, and genome defense.
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23
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Miller WR, Tran TT, Diaz L, Rios R, Khan A, Reyes J, Prater AG, Panesso D, Shamoo Y, Arias CA. LiaR-independent pathways to daptomycin resistance in Enterococcus faecalis reveal a multilayer defense against cell envelope antibiotics. Mol Microbiol 2019; 111:811-824. [PMID: 30582877 PMCID: PMC6417935 DOI: 10.1111/mmi.14193] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2018] [Indexed: 12/17/2022]
Abstract
The lipopeptide antibiotic daptomycin (DAP) is a key drug against serious enterococcal infections, but the emergence of resistance in the clinical setting is a major concern. The LiaFSR system plays a prominent role in the development of DAP resistance (DAP-R) in enterococci, and blocking this stress response system has been proposed as a novel therapeutic strategy. In this work, we identify LiaR-independent pathways in Enterococcus faecalis that regulate cell membrane adaptation in response to antibiotics. We adapted E. faecalis OG1RF (a laboratory strain) and S613TM (a clinical strain) lacking liaR to increasing concentrations of DAP, leading to the development of DAP-R and elevated MICs to bacitracin and ceftriaxone. Whole genome sequencing identified changes in the YxdJK two-component regulatory system and a putative fatty acid kinase (dak) in both DAP-R strains. Deletion of the gene encoding the YxdJ response regulator in both the DAP-R mutant and wild-type OG1RF decreased MICs to DAP, even when a functional LiaFSR system was present. Mutations in dak were associated with slower growth, decreased membrane fluidity and alterations of cell morphology. These findings suggest that overlapping stress response pathways can provide protection against antimicrobial peptides in E. faecalis at a significant cost in bacterial fitness.
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Affiliation(s)
- William R. Miller
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Truc T. Tran
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Lorena Diaz
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Rafael Rios
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Ayesha Khan
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
| | - Jinnethe Reyes
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Amy G. Prater
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Diana Panesso
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
| | - Yousif Shamoo
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Cesar A. Arias
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Division of Infectious Diseases, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA
- Center for Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, TX, USA
- Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Bogotá, Colombia
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24
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Abstract
INTRODUCTION Aspirin (acetylsalicylic acid, ASA) is often co-administered during the treatment of infections. Salicylic acid (SAL), the active metabolite of ASA, has significant effects on bacteria that might improve or (more likely) compromise the effectiveness of antibiotics. Areas covered: In this review, we summarize the interactions between SAL and antibiotics, and describe the underlying mechanisms involved. Expert opinion: In an era of rapidly increasing antibiotic resistance and lack of new antibiotic development, it is important to explore ways to optimize the effectiveness of antimicrobial treatment. This includes a better understanding of the interactions between commonly co-administered drugs. SAL might compromise the effectiveness of antibiotic treatment by inducing phenotypic resistance in bacteria. It can induce phenotypic resistance by up- or downregulating outer membrane proteins or efflux pumps, by upregulating antibiotic targets and by inducing enzymes with degrading activity. Moreover, SAL can increase the frequency of mutations leading to antibiotic resistance.
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Affiliation(s)
- Petra Zimmermann
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia.,d Infectious Diseases Unit , University of Basel Children's Hospital , Basel , Switzerland
| | - Nigel Curtis
- a Department of Paediatrics , The University of Melbourne , Parkville , Australia.,b Infectious Diseases & Microbiology Research Group , Murdoch Children's Research Institute , Parkville , Australia.,c Infectious Diseases Unit , The Royal Children's Hospital Melbourne , Parkville , Australia
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25
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Hygienemaßnahmen zur Prävention der Infektion durch Enterokokken mit speziellen Antibiotikaresistenzen. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2018; 61:1310-1361. [DOI: 10.1007/s00103-018-2811-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Reduced Chlorhexidine and Daptomycin Susceptibility in Vancomycin-Resistant Enterococcus faecium after Serial Chlorhexidine Exposure. Antimicrob Agents Chemother 2017; 62:AAC.01235-17. [PMID: 29038276 PMCID: PMC5740357 DOI: 10.1128/aac.01235-17] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022] Open
Abstract
Vancomycin-resistant Enterococcus faecium strains (VREfm) are critical public health concerns because they are among the leading causes of hospital-acquired bloodstream infections. Chlorhexidine (CHX) is a bisbiguanide cationic antiseptic that is routinely used for patient bathing and other infection control practices. VREfm are likely frequently exposed to CHX; however, the long-term effects of CHX exposure have not been studied in enterococci. In this study, we serially exposed VREfm to increasing concentrations of CHX for a period of 21 days in two independent experimental evolution trials. Reduced CHX susceptibility emerged (4-fold shift in CHX MIC). Subpopulations with reduced daptomycin (DAP) susceptibility were detected, which were further analyzed by genome sequencing and lipidomic analysis. Across the trials, we identified adaptive changes in genes with predicted or experimentally confirmed roles in chlorhexidine susceptibility (efrE), global nutritional stress response (relA), nucleotide metabolism (cmk), phosphate acquisition (phoU), and glycolipid biosynthesis (bgsB), among others. Moreover, significant alterations in membrane phospholipids were identified for some populations with reduced DAP susceptibility. Our results are clinically significant because they identify a link between serial subinhibitory CHX exposure and reduced DAP susceptibility. In addition, the CHX-induced genetic and lipidomic changes described in this study offer new insights into the mechanisms underlying the emergence of antibiotic resistance in VREfm.
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27
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Zhang X, de Maat V, Guzmán Prieto AM, Prajsnar TK, Bayjanov JR, de Been M, Rogers MRC, Bonten MJM, Mesnage S, Willems RJL, van Schaik W. RNA-seq and Tn-seq reveal fitness determinants of vancomycin-resistant Enterococcus faecium during growth in human serum. BMC Genomics 2017; 18:893. [PMID: 29162049 PMCID: PMC5699109 DOI: 10.1186/s12864-017-4299-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022] Open
Abstract
Background The Gram-positive bacterium Enterococcus faecium is a commensal of the human gastrointestinal tract and a frequent cause of bloodstream infections in hospitalized patients. The mechanisms by which E. faecium can survive and grow in blood during an infection have not yet been characterized. Here, we identify genes that contribute to growth of E. faecium in human serum through transcriptome profiling (RNA-seq) and a high-throughput transposon mutant library sequencing approach (Tn-seq). Results We first sequenced the genome of E. faecium E745, a vancomycin-resistant clinical isolate, using a combination of short- and long read sequencing, revealing a 2,765,010 nt chromosome and 6 plasmids, with sizes ranging between 9.3 kbp and 223.7 kbp. We then compared the transcriptome of E. faecium E745 during exponential growth in rich medium and in human serum by RNA-seq. This analysis revealed that 27.8% of genes on the E. faecium E745 genome were differentially expressed in these two conditions. A gene cluster with a role in purine biosynthesis was among the most upregulated genes in E. faecium E745 upon growth in serum. The E. faecium E745 transposon mutant library was then used to identify genes that were specifically required for growth of E. faecium in serum. Genes involved in de novo nucleotide biosynthesis (including pyrK_2, pyrF, purD, purH) and a gene encoding a phosphotransferase system subunit (manY_2) were thus identified to be contributing to E. faecium growth in human serum. Transposon mutants in pyrK_2, pyrF, purD, purH and manY_2 were isolated from the library and their impaired growth in human serum was confirmed. In addition, the pyrK_2 and manY_2 mutants were tested for their virulence in an intravenous zebrafish infection model and exhibited significantly attenuated virulence compared to E. faecium E745. Conclusions Genes involved in carbohydrate metabolism and nucleotide biosynthesis of E. faecium are essential for growth in human serum and contribute to the pathogenesis of this organism. These genes may serve as targets for the development of novel anti-infectives for the treatment of E. faecium bloodstream infections. Electronic supplementary material The online version of this article (10.1186/s12864-017-4299-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xinglin Zhang
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China.,Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Vincent de Maat
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Ana M Guzmán Prieto
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Tomasz K Prajsnar
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Jumamurat R Bayjanov
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Mark de Been
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Malbert R C Rogers
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Stéphane Mesnage
- Krebs Institute, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX, Utrecht, the Netherlands. .,Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, B15 2TT, United Kingdom.
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28
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Alotaibi SMI, Ayibiekea A, Pedersen AF, Jakobsen L, Pinholt M, Gumpert H, Hammerum AM, Westh H, Ingmer H. Susceptibility of vancomycin-resistant and -sensitive Enterococcus faecium obtained from Danish hospitals to benzalkonium chloride, chlorhexidine and hydrogen peroxide biocides. J Med Microbiol 2017; 66:1744-1751. [PMID: 29134935 DOI: 10.1099/jmm.0.000642] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE In Danish hospitals, the number of infections caused by vancomycin-resistant Enterococcus faecium (VRE faecium) has dramatically increased in recent years. Hospital disinfectants are essential in eliminating pathogenic microorganisms, and reduced susceptibility may contribute to hospital-associated infections. We have addressed whether clinical VRE faecium display decreased biocide susceptibility when compared to vancomycin-sensitive Enterococcus faecium (VSE faecium) isolates. METHODOLOGY In total 12 VSE faecium and 37 VRE faecium isolates obtained from Danish hospitals over an extended time period were tested for susceptibility towards three commonly applied biocides, namely benzalkonium chloride, chlorhexidine and hydrogen peroxide. RESULTS For benzalkonium chloride, 89 % of VRE faecium strains had a minimal inhibitory concentration (MIC) of 8 mg l-1, whereas for VSE faecium, only 25 % of the strains had an MIC of 8 mg l-1. For chlorhexidine, the MIC of 95 % of VRE faecium strains was 4 mg l-1 or higher, while only 33 % of VSE faecium strains displayed MIC values at the same level. In contrast, both VRE and VSE faecium displayed equal susceptibility to hydrogen peroxide, but a higher minimal bactericidal concentration (MBC) was found for the former. The efflux activity was also assessed, and this was generally higher for the VRE faecium strains compared to VSE faecium. CONCLUSION VRE faecium from Danish hospitals demonstrated decreased susceptibility towards benzalkonium chloride and chlorhexidine compared to VSE faecium, where the use of chlorhexidine is particularly heavy in the hospital environment. These findings suggest that biocide tolerance may characterize VRE faecium isolated in Danish hospitals.
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Affiliation(s)
- Sulaiman M I Alotaibi
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.,Foodborne Diseases Surveillance Center, Executive Department of Surveillance Centers & Crisis Management, Saudi Food & Drug Authority, Riyadh, Saudi Arabia
| | - Alafate Ayibiekea
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Annemette Frøling Pedersen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Lotte Jakobsen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Mette Pinholt
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Heidi Gumpert
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Anette M Hammerum
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Henrik Westh
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark.,Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
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