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Xu L, Wu Y, Yang X, Pang X, Wu Y, Li X, Liu X, Zhao Y, Yu L, Wang P, Ye B, Jiang S, Ma J, Zhang X. The Fe-S cluster biosynthesis in Enterococcus faecium is essential for anaerobic growth and gastrointestinal colonization. Gut Microbes 2024; 16:2359665. [PMID: 38831611 DOI: 10.1080/19490976.2024.2359665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 05/21/2024] [Indexed: 06/05/2024] Open
Abstract
The facultative anaerobic Gram-positive bacterium Enterococcus faecium is a ubiquitous member of the human gut microbiota. However, it has gradually evolved into a pathogenic and multidrug resistant lineage that causes nosocomial infections. The establishment of high-level intestinal colonization by enterococci represents a critical step of infection. The majority of current research on Enterococcus has been conducted under aerobic conditions, while limited attention has been given to its physiological characteristics in anaerobic environments, which reflects its natural colonization niche in the gut. In this study, a high-density transposon mutant library containing 26,620 distinct insertion sites was constructed. Tn-seq analysis identified six genes that significantly contribute to growth under anaerobic conditions. Under anaerobic conditions, deletion of sufB (encoding Fe-S cluster assembly protein B) results in more extensive and significant impairments on carbohydrate metabolism compared to aerobic conditions. Consistently, the pathways involved in this utilization-restricted carbohydrates were mostly expressed at significantly lower levels in mutant compared to wild-type under anaerobic conditions. Moreover, deletion of sufB or pflA (encoding pyruvate formate lyase-activating protein A) led to failure of gastrointestinal colonization in mice. These findings contribute to our understanding of the mechanisms by which E. faecium maintains proliferation under anaerobic conditions and establishes colonization in the gut.
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Affiliation(s)
- Linan Xu
- College of Agriculture and Forestry, Linyi University, Linyi, China
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Yajing Wu
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
| | - Xiangpeng Yang
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Xinxin Pang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yansha Wu
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Xingshuai Li
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Xiayu Liu
- Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
| | - Yuzhong Zhao
- College of Agriculture and Forestry, Linyi University, Linyi, China
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Lumin Yu
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Peikun Wang
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Bin Ye
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Shijin Jiang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - Junfei Ma
- College of Agriculture and Forestry, Linyi University, Linyi, China
| | - Xinglin Zhang
- College of Agriculture and Forestry, Linyi University, Linyi, China
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2
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Weng PL, Ramli R, Hamat RA. Antibiotic Susceptibility Patterns, Biofilm Formation and esp Gene among Clinical Enterococci: Is There Any Association? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16183439. [PMID: 31533204 PMCID: PMC6765802 DOI: 10.3390/ijerph16183439] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/14/2022]
Abstract
Enterococci are commonly found in humans, animals and environments. Their highly adaptive mechanisms are related to several virulent determinants and their ability to resist antibiotics. Data on the relationship between the esp gene, biofilm formation and antibiotic susceptibility profiles may differ between countries. This cross-sectional study was conducted to determine the proportion of esp gene and biofilm formation among Enterococcus faecalis and Enterococcus faecium clinical isolates. We also investigated the possible association between the esp gene with antibiotic susceptibility patterns and biofilm formation. The isolates were collected from clinical samples and identified using biochemical tests and 16SRNA. Antibiotic susceptibility patterns and a biofilm assay were conducted according to the established guidelines. Molecular detection by PCR was used to identify the esp gene using established primers. In total, 52 and 28 of E. faecalis and E. faecium were identified, respectively. E. faecium exhibited higher resistance rates compared to E. faecalis as follows: piperacillin/tazobactam (100% versus 1.9%), ampicillin (92.8% versus 1.9%), high-level gentamicin resistance (HLGR) (89.3% versus 25.0%) and penicillin (82.1% versus 7.7%). E. faecium produced more biofilms than E. faecalis (59.3% versus 49.0%). E. faecium acquired the esp gene more frequently than E. faecalis (78.6% versus 46.2%). Interestingly, the associations between ampicillin and tazobactam/piperacillin resistance with the esp gene were statistically significant (X2 = 4.581, p = 0.027; and X2 = 6.276, p = 0.012, respectively). Our results demonstrate that E. faecium exhibits high rates of antimicrobial resistance, esp gene acquisition and biofilm formation. These peculiar traits of E. faecium may have implications for the management of enterococcal infections in hospitals. Thus, concerted efforts by all parties in establishing appropriate treatment and effective control measures are warranted in future.
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Affiliation(s)
- Poh Leng Weng
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
| | - Ramliza Ramli
- Department of Medical Microbiology and Immunology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaakob Latif, Bandar Tun Razak, Kuala Lumpur 56000, Malaysia.
| | - Rukman Awang Hamat
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia.
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3
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Tedim AP, Ruíz-Garbajosa P, Rodríguez MC, Rodríguez-Baños M, Lanza VF, Derdoy L, Cárdenas Zurita G, Loza E, Cantón R, Baquero F, Coque TM. Long-term clonal dynamics of Enterococcus faecium strains causing bloodstream infections (1995-2015) in Spain. J Antimicrob Chemother 2016; 72:48-55. [PMID: 27655856 DOI: 10.1093/jac/dkw366] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 07/26/2016] [Accepted: 08/02/2016] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To investigate the population structure of Enterococcus faecium causing bloodstream infections (BSIs) in a tertiary Spanish hospital with low glycopeptide resistance, and to enhance our knowledge of the dynamics of emergence and spread of high-risk clonal complexes. METHODS All available E. faecium causing BSIs (n = 413) in our hospital (January 1995-May 2015) were analysed for antibiotic susceptibility (CLSI), putative virulence traits (PCR, esp, hylEfm) and clonal relationship (SmaI-PFGE, MLST evaluated by goeBURST and BAPS). RESULTS The increased incidence of BSIs caused by enterococci [2.3‰ of attended patients (inpatients and outpatients) in 1996 to 3.0‰ in 2014] significantly correlated with the increase in BSIs caused by E. faecium (0.33‰ of attended patients in 1996 to 1.3‰ in 2014). The BSIs Enterococcus faecalis:E. faecium ratio changed from 5:1 in 1996 to 1:1 in 2014. During the last decade an increase in E. faecium BSIs episodes in cancer patients (10.9% in 1995-2005 and 37.1% in 2006-15) was detected. Ampicillin-susceptible E. faecium (ASEfm; different STs/BAPS) and ampicillin-resistant E. faecium (AREfm; ST18/ST17-BAPS 3.3a) isolates were recovered throughout the study. Successive waves of BAPS 2.1a-AREfm (ST117, ST203 and ST80) partially replaced ASEfm and ST18-AREfm since 2006. CONCLUSIONS Different AREfm clones (belonging to BAPS 2.1a and BAPS 3.3a) consistently isolated during the last decade from BSIs might be explained by a continuous and dense colonization (favouring both invasion and cross-transmission) of hospitalized patients. High-density colonization by these clones is probably enhanced in elderly patients by heavy and prolonged antibiotic exposure, particularly in oncological patients.
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Affiliation(s)
- Ana P Tedim
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
| | - Patricia Ruíz-Garbajosa
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Spanish Network for Research in Infectious Diseases (REIPI), Seville, Spain
| | - Maria Concepción Rodríguez
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Mercedes Rodríguez-Baños
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Val F Lanza
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
| | - Laura Derdoy
- Microbiology Department, Laboratory Division, Hospital General de Agudos Ramos Mejía, Ciudad Autónoma de Buenos Aires, Argentina
| | - Gonzalo Cárdenas Zurita
- Clinical Laboratory, Microbiology and Infectious Diseases Department, Clinica San Francisco, Quito, Ecuador
| | - Elena Loza
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Rafael Cantón
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Spanish Network for Research in Infectious Diseases (REIPI), Seville, Spain
| | - Fernando Baquero
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
| | - Teresa M Coque
- Microbiology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain .,Unidad de Resistencia a Antibióticos y Virulencia Bacteriana asociada al Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
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4
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Infecciones causadas por bacterias grampositivas multirresistentes (Staphylococcus aureus y Enterococcus spp.). Enferm Infecc Microbiol Clin 2013; 31:543-51. [DOI: 10.1016/j.eimc.2013.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 08/05/2013] [Indexed: 11/24/2022]
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5
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Miller WR, Murray BE, Arias CA. Emergence and management of drug-resistant enterococcal infections. Microb Drug Resist 2013. [DOI: 10.2217/ebo.12.357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- William R Miller
- William R Miller is a graduate of the University of Texas Medical School (TX, USA) where he was named to the Alpha Omega Alpha Medical Honor Society. He is currently completing his residency training in combined internal medicine–pediatrics and plans to pursue a fellowship in infectious diseases
| | - Barbara E Murray
- Barbara E Murray graduated top of her class from the University of Texas Southwestern Medical School (TX, USA), and completed her training in internal medicine and infectious diseases at the Massachusetts General Hospital, Harvard Medical School (MA, USA). She is the JJ Ralph Meadows Professor and Director of the Division of Infectious Diseases and Laboratory for Enterococcal Research at the Center for the Study of Emerging and Re-Emerging Pathogens at the University of Texas Medical School. Her main
| | - Cesar A Arias
- Cesar A Arias received his MD from the Universidad El Bosque (Bogotá, Colombia), his MSc in clinical microbiology from the University of London (UK) and his PhD in molecular microbiology from the University of Cambridge (UK). He completed his residency in internal medicine and fellowship in infectious diseases at the University of Texas Medical School at Houston, and the University of Texas MD Anderson Cancer Center (TX, USA). He is currently Associate Professor of Medicine and Director of the Laboratory
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6
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Zhang X, Top J, de Been M, Bierschenk D, Rogers M, Leendertse M, Bonten MJM, van der Poll T, Willems RJL, van Schaik W. Identification of a genetic determinant in clinical Enterococcus faecium strains that contributes to intestinal colonization during antibiotic treatment. J Infect Dis 2013; 207:1780-6. [PMID: 23447698 DOI: 10.1093/infdis/jit076] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Intestinal colonization by antibiotic-resistant Enterococcus faecium is the first step in a process that can lead to infections in hospitalized patients. By comparative genome analysis and subsequent polymerase chain reaction screening, we identified a locus that encodes a putative phosphotransferase system (PTS). The PTS locus was widespread in isolates from hospital outbreaks of infection (84.2%) and nonoutbreak clinical infections (66.0%) but absent from human commensal isolates. Deletion of pstD, which is predicted to encode the enzyme IID subunit of this PTS, significantly impaired the ability of E. faecium to colonize the murine intestinal tract during antibiotic treatment. This is the first description of a determinant that contributes to intestinal colonization in clinical E. faecium strains.
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Affiliation(s)
- Xinglin Zhang
- Department of Medical Microbiology, University Medical Center Utrecht, The Netherlands
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7
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Resistance patterns and occurrence of virulence determinants among GRE strains in southwestern Poland. Adv Med Sci 2012; 56:304-10. [PMID: 21940270 DOI: 10.2478/v10039-011-0022-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE The aim of this study was to determine the antimicrobial resistance and the occurrence of virulence determinants among glycopeptide-resistant enterococci (GRE) isolated in 2007-2009 from patients hospitalized in southwestern Poland. MATERIAL AND METHODS The minimal inhibitory concentrations (MICs) of antibiotics were determined by agar dilution method or by E-test®. The presence of vanA - vanG resistance and virulence genes (agg, esp, gelE and cylA, cylB, cylM) was investigated using PCR. The ability to form biofilm and the activity of gelatinase, hemolysins, lipase and DNase were tested. RESULTS All the GRE strains were susceptible to linezolid, daptomycin, and tigecycline and resistant to norfloxacin. In the Enterococcus faecium group, 17 strains carried the vanA gene and 20 the vanB gene. In the Enterococcu faecalis group, 4 strains carried the vanA gene and 1 the vanB gene. There were differences in tetracycline susceptibility between the VanA (70%) and the VanB (55%) phenotypes. Only linezolid had high activity against both the VanA and the VanB phenotypes. The esp gene was present in most of the GRE strains, but only 3 E. faecalis strains produced biofilm. Lipase was produced by 10/42 examined strains, gelatinase by 4/42 and hemolysin by 3/42 isolates. CONCLUSIONS Linezolid seems to be the optimal option in empirical therapy of infections caused by GRE strains because of the relationship between its activity (MIC value) and susceptibility breakpoint. There was no correlation between the prevalence of different virulence genes and resistance to the antibiotics tested.
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8
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Rice LB. Mechanisms of resistance and clinical relevance of resistance to β-lactams, glycopeptides, and fluoroquinolones. Mayo Clin Proc 2012; 87:198-208. [PMID: 22305032 PMCID: PMC3498059 DOI: 10.1016/j.mayocp.2011.12.003] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 12/09/2011] [Accepted: 12/14/2011] [Indexed: 11/15/2022]
Abstract
The widespread use of antibiotics has resulted in a growing problem of antimicrobial resistance in the community and hospital settings. Antimicrobial classes for which resistance has become a major problem include the β-lactams, the glycopeptides, and the fluoroquinolones. In gram-positive bacteria, β-lactam resistance most commonly results from expression of intrinsic low-affinity penicillin-binding proteins. In gram-negative bacteria, expression of acquired β-lactamases presents a particular challenge owing to some natural spectra that include virtually all β-lactam classes. Glycopeptide resistance has been largely restricted to nosocomial Enterococcus faecium strains, the spread of which is promoted by ineffective infection control mechanisms for fecal organisms and the widespread use of colonization-promoting antimicrobials (especially cephalosporins and antianaerobic antibiotics). Fluoroquinolone resistance in community-associated strains of Escherichia coli, many of which also express β-lactamases that confer cephalosporin resistance, is increasingly prevalent. Economic and regulatory forces have served to discourage large pharmaceutical companies from developing new antibiotics, suggesting that the antibiotics currently on the market may be all that will be available for the coming decade. As such, it is critical that we devise, test, and implement antimicrobial stewardship strategies that are effective at constraining and, ideally, reducing resistance in human pathogenic bacteria.
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Affiliation(s)
- Louis B Rice
- Department of Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA.
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9
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Tosh PK, McDonald LC. Infection Control in the Multidrug-Resistant Era: Tending the Human Microbiome. Clin Infect Dis 2011; 54:707-13. [DOI: 10.1093/cid/cir899] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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10
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Reygaert WC. Antibiotic optimization in the difficult-to-treat patient with complicated intra-abdominal or complicated skin and skin structure infections: focus on tigecycline. Ther Clin Risk Manag 2010; 6:419-30. [PMID: 20856688 PMCID: PMC2940750 DOI: 10.2147/tcrm.s9117] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Indexed: 01/22/2023] Open
Abstract
Complicated intra-abdominal and skin and skin structure infections are widely varied in presentation. These infections very often lead to an increase in length of hospital stay, with a resulting increase in costs and mortality. In addition, these infections may be caused by a wide variety of bacteria and are often polymicrobial with the possibility of the presence of antimicrobial-resistant strains, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase strains (Escherichia coli, Klebsiella pneumoniae), and K. pneumoniae carbapenemase-producing strains. In combination with patients’ immunosuppression or comorbidities, the treatment and management options for initial therapy success are few. Tigecycline, a new glycylcyline antimicrobial from the tetracycline drug class, represents a viable option for the successful treatment of these infections. It has been shown to have activity against a wide variety of bacteria, including the antimicrobial-resistant strains. As with all tetracycline drugs, it is not recommended for pregnant or nursing women. The potential side effects are those typical of tetracycline drugs: nausea, vomiting, and headaches. Drug–drug interactions are not expected, and renal function monitoring is not necessary.
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Affiliation(s)
- Wanda C Reygaert
- Department of Biomedical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, USA
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11
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Lye DJ. A mouse model for characterization of gastrointestinal colonization rates among environmental Aeromonas isolates. Curr Microbiol 2009; 58:454-8. [PMID: 19130126 DOI: 10.1007/s00284-008-9342-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 12/01/2008] [Accepted: 12/02/2008] [Indexed: 12/01/2022]
Abstract
The colonization rates of 10 different environmental Aeromonas isolates were determined using a novel mouse-streptomycin pretreatment method. As demonstrated, alterations to the colon flora of mice pretreated with streptomycin allowed transient colonization by bacterial species normally excluded by host competition. A novel procedure is described for determining the colonization abilities of Aeromonas isolates under these conditions. The colonization rates of A. salmonicida, A. encheleia, and A. allosaccharophila were either negative or occurred randomly at low levels with respect to concentrations of the dosage consumed by the animals. In contrast, A. hydrophila, A. veronii biovar sobria, and A. caviae exhibited relatively high rates of mouse colon tissue colonization.
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Affiliation(s)
- Dennis J Lye
- National Exposure Research Laboratory, Microbial and Chemical Exposure Assessment Research Division, USEPA, Cincinnati, OH 45268, USA.
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12
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Production of enterocins L50A, L50B, and IT, a new enterocin, by Enterococcus faecium IT62, a strain isolated from Italian ryegrass in Japan. Antimicrob Agents Chemother 2008; 52:1917-23. [PMID: 18391036 DOI: 10.1128/aac.01409-07] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus faecium IT62, isolated from ryegrass in Japan, was shown to produce three different bacteriocins, two of which had molecular masses and amino acid sequences that corresponded to those of enterocin L50A and enterocin L50B. These peptides existed, however, as chemically modified forms that were either N formylated or N formylated and oxidized at Met(24). The third bacteriocin, named enterocin IT, had a molecular mass of 6,390 Da, was made up of 54 amino acids, and did not correspond to any known bacteriocin. However, enterocin IT was identical to the C-terminal part of the 16-amino-acid-longer bacteriocin 32 (T. Inoue, H. Tomita, and Y. Ike, Antimicrob. Agents Chemother., 50:1202-1212, 2006). For the first time, the antimicrobial activity spectra for enterocins L50A and L50B were determined separately and included a wide range of gram-positive bacteria but also a few gram-negative strains that were weakly sensitive. Slight differences in the activities of enterocins L50A and L50B were observed, as gram-positive bacteria showed an overall higher level of sensitivity to L50A than to L50B, as opposed to gram-negative ones. Conversely, enterocin IT showed a very narrow antimicrobial spectrum that was limited to E. faecium strains, one strain of Bacillus subtilis, and one strain of Lactococcus lactis. This study showed that E. faecium IT62, a grass-borne strain, produces bacteriocins with very different activity features and structures that may be found in strains associated with food or those of clinical origin, which demonstrates that a particular enterocin structure may be widespread and not related to the producer's origin.
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13
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Simon A, Gröger N, Wilkesmann A, Hasan C, Wiszniewsky G, Engelhart S, Kramer MH, Bode U, Ammann RA, Fleischhack G. Restricted use of glycopeptides in paediatric cancer patients with fever and neutropenia. Int J Antimicrob Agents 2006; 28:417-22. [PMID: 17046210 DOI: 10.1016/j.ijantimicag.2006.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 06/25/2006] [Accepted: 06/27/2006] [Indexed: 10/24/2022]
Abstract
Until now, studies confirming the safety of glycopeptide restriction in the empirical treatment of prolonged fever and neutropenia included only nine children. In an open-label observational study, the use of teicoplanin in paediatric oncology patients was investigated. A period of unrestricted use (2001-2003) was compared with a second period (2004) following implementation of a restrictive treatment guideline. Empirical first-line treatment consisted of piperacillin/tazobactam; in 2004, fosfomycin was added after 72 h as the second-line combination instead of teicoplanin. In total, 213 episodes (n=163 in 2001-2003; n=50 in 2004) managed with teicoplanin or fosfomycin (only 2004) were eligible. Empirical treatment of fever of unknown origin with teicoplanin was reduced by 97%. In 2004, the mean length of stay was 0.4 days shorter, no infection-related death occurred and no vancomycin-resistant enterococci were detected. Restriction of empirical glycopeptides is safe in paediatric cancer patients after first-line treatment with piperacillin/tazobactam. Fosfomycin appears to offer a feasible and cost-saving alternative in second-line combination therapy.
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Affiliation(s)
- Arne Simon
- Department of Pediatric Hematology and Oncology, Children's Hospital Medical Center, University of Bonn, Adenauerallee 119, 53113 Bonn, Germany.
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14
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Moellering RC. The management of infections due to drug-resistant gram-positive bacteria. Eur J Clin Microbiol Infect Dis 2006; 24:777-9. [PMID: 16362382 DOI: 10.1007/s10096-005-0062-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R C Moellering
- Department of Medicine, Beth Israel Deaconess Medical Center, 110 Francis Street, Suite 6A, Boston, MA 02215, USA.
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