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Bhardwaj SB, Mehta M, Sood S, Sharma J. Isolation of a Novel Phage and Targeting Biofilms of Drug-Resistant Oral Enterococci. J Glob Infect Dis 2020; 12:11-15. [PMID: 32165796 PMCID: PMC7045759 DOI: 10.4103/jgid.jgid_110_19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/03/2019] [Accepted: 12/19/2019] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION Enterococci are now recognized as the second most cause of nosocomial infections worldwide. The emergence of multidrug-resistant strains in the organism has given rise to alternative strategies such as phage therapy. In this study, an Enterococcus faecalis infecting phage was isolated and its efficiency against biofilms formed by drug-resistant enterococci obtained from chronic periodontitis was evaluated. MATERIALS AND METHODS Bacteriophage against E. faecalis was isolated from sewage sample. The phage was propagated and identified using transmission electron microscope (TEM). In vitro biofilm formation was assessed. RESULTS TEM microscopy showed that the phage belonged to Siphoviridae family. In the presence of the novel phage, the metabolic activity of enterococci biofilm was reduced at 48 h of contact. A difference of at least 5 log CFU/ml was seen in the live cells of the control biofilm, and the phage treated biofilm of enterococci isolates. CONCLUSION The study shows that the novel phage inhibits biofilm production in oral enterococci isolates from periodontitis patients but has a narrow host range. The role of bacteriophages as strong biotechnological and natural therapeutic agents for E. faecalis in chronic periodontitis can be considered.
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Affiliation(s)
- Sonia Bhonchal Bhardwaj
- Departments of Microbiology, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India
| | - Manjula Mehta
- Departments of Microbiology, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India
| | - Shaveta Sood
- Department of Periodontics, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India
| | - Jyoti Sharma
- Departments of Microbiology, Dr. Harvansh Singh Judge Institute of Dental Sciences and Hospital, Panjab University, Chandigarh, India
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Rello J, Campogiani L, Eshwara VK. Understanding resistance in enterococcal infections. Intensive Care Med 2019; 46:353-356. [PMID: 31792686 DOI: 10.1007/s00134-019-05875-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/17/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Jordi Rello
- Centro de Investigacion Biomedica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Barcelona, Spain.,Clinical Research/Epidemiology In Pneumonia and Sepsis (CRIPS), Vall d'Hebron Institut of Research (VHIR), Barcelona, Spain.,Clinical Research in ICU, Anesthesiology Department, CHU Nîmes, University Montpellier, Nîmes, France
| | - Laura Campogiani
- Clinical Infectious Diseases, Department of System Medicine, Tor Vergata University, Rome, Italy.
| | - Vandana Kalwaje Eshwara
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
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Deshpande LM, Castanheira M, Flamm RK, Mendes RE. Evolving oxazolidinone resistance mechanisms in a worldwide collection of enterococcal clinical isolates: results from the SENTRY Antimicrobial Surveillance Program. J Antimicrob Chemother 2019; 73:2314-2322. [PMID: 29878213 DOI: 10.1093/jac/dky188] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/18/2018] [Indexed: 01/28/2023] Open
Abstract
Objectives This study evaluated the oxazolidinone resistance mechanisms among a global collection of enterococcal clinical isolates. The epidemiology of optrA-carrying isolates and the optrA genetic context were determined. Methods Enterococcal isolates (26 648) from the SENTRY Antimicrobial Surveillance Program (2008-16) were identified by MALDI-TOF MS and MICs were determined by broth microdilution. Isolates with linezolid MICs of ≥4 mg/L were screened for resistance mechanisms. Isolates carrying optrA had their genome sequenced for genetic context and epidemiology information. Results Thirty-six Enterococcus faecalis and 66 Enterococcus faecium had linezolid MICs of ≥4 mg/L (0.38% of surveillance enterococci). E. faecalis had a linezolid MIC range of 4-16 mg/L, while E. faecium displayed higher values (4-64 mg/L). Nine E. faecalis had G2576T mutations and optrA was detected in 26 (72.2%) isolates from the Asia-Pacific region, North America, Latin America and Europe; 3 isolates also produced Cfr [Thailand (1)] or Cfr(B) [Panama (2)]. All E. faecium isolates had G2576T alterations, while three isolates from the USA had concomitant presence of cfr(B). The optrA gene was plasmid- and chromosome-located in 22 and 3 E. faecalis, respectively. One isolate signalled hybridization on plasmid and chromosome. The genetic context of optrA varied. E. faecalis belonging to the same clonal complex were detected in distinct geographical regions. Also, genetically distinct isolates from Ireland had an identical optrA context, indicating plasmid dissemination. Conclusions Alterations in 23S rRNA remained the main oxazolidinone resistance mechanism in E. faecium, while optrA prevailed in E. faecalis. These results demonstrate global dissemination of optrA and warrant surveillance for monitoring.
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Affiliation(s)
| | | | - R K Flamm
- JMI Laboratories, North Liberty, IA, USA
| | - R E Mendes
- JMI Laboratories, North Liberty, IA, USA
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Environment Shapes the Accessible Daptomycin Resistance Mechanisms in Enterococcus faecium. Antimicrob Agents Chemother 2019; 63:AAC.00790-19. [PMID: 31332078 DOI: 10.1128/aac.00790-19] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/16/2019] [Indexed: 02/07/2023] Open
Abstract
Daptomycin binds to bacterial cell membranes and disrupts essential cell envelope processes, leading to cell death. Bacteria respond to daptomycin by altering their cell envelopes to either decrease antibiotic binding to the membrane or by diverting binding away from septal targets. In Enterococcus faecalis, daptomycin resistance is typically coordinated by the three-component cell envelope stress response system, LiaFSR. Here, studying a clinical strain of multidrug-resistant Enterococcus faecium containing alleles associated with activation of the LiaFSR signaling pathway, we found that specific environments selected for different evolutionary trajectories, leading to high-level daptomycin resistance. Planktonic environments favored pathways that increased cell surface charge via yvcRS upregulation of dltABCD and mprF, causing a reduction in daptomycin binding. Alternatively, environments favoring complex structured communities, including biofilms, evolved both diversion and repulsion strategies via divIVA and oatA mutations, respectively. Both environments subsequently converged on cardiolipin synthase (cls) mutations, suggesting the importance of membrane modification across strategies. Our findings indicate that E. faecium can evolve diverse evolutionary trajectories to daptomycin resistance that are shaped by the environment to produce a combination of resistance strategies. The accessibility of multiple and different biochemical pathways simultaneously suggests that the outcome of daptomycin exposure results in a polymorphic population of resistant phenotypes, making E. faecium a recalcitrant nosocomial pathogen.
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Sheikh AF, Hamidi H, Shahin M, Shahmohammadi S. The prevalence of phenotypic and genotypic glycopeptides resistance among clinical isolates of enterococci in Ahvaz, southwestern Iran. GENE REPORTS 2019. [DOI: 10.1016/j.genrep.2019.100415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Molecular analysis and epidemiological typing of Vancomycin-resistant Enterococcus outbreak strains. Sci Rep 2019; 9:11917. [PMID: 31417140 PMCID: PMC6695431 DOI: 10.1038/s41598-019-48436-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 08/05/2019] [Indexed: 12/14/2022] Open
Abstract
Outbreaks of multidrug resistant bacteria including vancomycin-resistant enterococci (VRE) in healthcare institutions are increasing in Norway, despite a low level of resistance compared to other European countries. In this study, we describe epidemiological relatedness of vancomycin-resistant Enterococcus faecium isolated during an outbreak at a Norwegian hospital in 2012–2013. During the outbreak, 9454 fecal samples were screened for VRE by culture and/or PCR. Isolates from 86 patients carrying the vanA resistance gene were characterized using pulsed-field gel electrophoresis (PFGE), MALDI-TOF mass spectrometry and single nucleotide polymorphism typing. PFGE revealed two main clusters, the first comprised 56 isolates related to an initial outbreak strain, and the second comprised 21 isolates originating from a later introduced strain, together causing two partly overlapping outbreaks. Nine isolates, including the index case were not related to the two outbreak clusters. In conclusion, the epidemiological analyses show that the outbreak was discovered by coincidence, and that infection control measures were successful. All typing methods identified the two outbreak clusters, and the experiment congruence between the MALDI-TOF and the PFGE clustering was 63.2%, with a strong correlation (r = 72.4%). Despite lower resolution compared to PFGE, MALDI-TOF may provide an efficient mean for real-time monitoring spread of infection.
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Coupri D, Budin-Verneuil A, Hartke A, Benachour A, Léger L, Lequeux T, Pfund E, Verneuil N. Genetic and pharmacological inactivation of d-alanylation of teichoic acids sensitizes pathogenic enterococci to β-lactams. J Antimicrob Chemother 2019; 74:3162-3169. [DOI: 10.1093/jac/dkz322] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/20/2019] [Accepted: 06/28/2019] [Indexed: 01/23/2023] Open
Abstract
AbstractBackgroundEnterococci intrinsically resistant to cephalosporins represent a major cause of healthcare-associated infections, and the emergence of MDR makes therapeutic approaches particularly challenging.ObjectivesTeichoic acids are cell wall glycopolymers present in Gram-positive bacteria. Teichoic acids can be modified by d-alanylation, which requires four proteins encoded by the dltABCD operon. Our objective was to evaluate the Dlt system as a druggable target to treat enterococcal infections.MethodsThe susceptibility of a d-alanylation-deficient strain of Enterococcus faecalis to β-lactam antibiotics individually and/or in combination was analysed. Moreover, a DltA inhibitor was synthesized to test pharmacological inhibition of d-alanylation in vivo and in host using the animal model Galleria mellonella with different clinical isolates of E. faecalis and Enterococcus faecium.ResultsMost cephalosporins used as mono treatment had no impact on survival of the parental strain, but were slightly lethal for the dltA mutant of E. faecalis. Addition of a very low concentration of amoxicillin significantly increased killing of the dltA mutant under these conditions. The most spectacular effect was obtained with a combination of cefotaxime (1 mg/L) and amoxicillin (0.03 mg/L). In the presence of the inhibitor, the WT strain was as susceptible to this combination treatment as the dltA mutant. This molecule associated with the antibiotics was also effective in killing other E. faecalis clinical isolates and successfully prevented death of Galleria infected with either E. faecalis or E. faecium.ConclusionsThe combined results support the potential usefulness of the Dlt system as a target to potentiate antibiotic combination therapies for the treatment of drug-resistant enterococci.
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Affiliation(s)
| | | | - Axel Hartke
- Normandie Université, UNICAEN, U2RM, Caen, France
| | | | - Loïc Léger
- Normandie Université, UNICAEN, U2RM, Caen, France
| | - Thierry Lequeux
- Normandie Université, Laboratoire de Chimie Moléculaire et Thioorganique UMR 6507, ENSICAEN, UNICAEN, CNRS, 6 Bd du Maréchal Juin, Caen, France
| | - Emmanuel Pfund
- Normandie Université, Laboratoire de Chimie Moléculaire et Thioorganique UMR 6507, ENSICAEN, UNICAEN, CNRS, 6 Bd du Maréchal Juin, Caen, France
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Bayjanov JR, Baan J, Rogers MRC, Troelstra A, Willems RJL, van Schaik W. Enterococcus faecium genome dynamics during long-term asymptomatic patient gut colonization. Microb Genom 2019; 5:e000277. [PMID: 31166888 PMCID: PMC6700664 DOI: 10.1099/mgen.0.000277] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/24/2019] [Indexed: 11/18/2022] Open
Abstract
Enterococcus faecium is a gut commensal of humans and animals. In addition, it has recently emerged as an important nosocomial pathogen through the acquisition of genetic elements that confer resistance to antibiotics and virulence. We performed a whole-genome sequencing-based study on 96 multidrug-resistant E. faecium strains that asymptomatically colonized five patients with the aim of describing the genome dynamics of this species. The patients were hospitalized on multiple occasions and isolates were collected over periods ranging from 15 months to 6.5 years. Ninety-five of the sequenced isolates belonged to E. faecium clade A1, which was previously determined to be responsible for the vast majority of clinical infections. The clade A1 strains clustered into six clonal groups of highly similar isolates, three of which consisted entirely of isolates from a single patient. We also found evidence of concurrent colonization of patients by multiple distinct lineages and transfer of strains between patients during hospitalization. We estimated the evolutionary rate of two clonal groups that each colonized single patients at 12.6 and 25.2 single-nucleotide polymorphisms (SNPs)/genome/year. A detailed analysis of the accessory genome of one of the clonal groups revealed considerable variation due to gene gain and loss events, including the chromosomal acquisition of a 37 kbp prophage and the loss of an element containing carbohydrate metabolism-related genes. We determined the presence and location of 12 different insertion sequence (IS) elements, with ISEfa5 showing a unique pattern of location in 24 of the 25 isolates, suggesting widespread ISEfa5 excision and insertion into the genome during gut colonization. Our findings show that the E. faecium genome is highly dynamic during asymptomatic colonization of the human gut. We observed considerable genomic flexibility due to frequent horizontal gene transfer and recombination, which can contribute to the generation of genetic diversity within the species and, ultimately, can contribute to its success as a nosocomial pathogen.
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Affiliation(s)
- Jumamurat R. Bayjanov
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Jery Baan
- 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
| | - Annet Troelstra
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - 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, University of Birmingham, Birmingham, UK
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59
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Zalipour M, Esfahani BN, Havaei SA. Phenotypic and genotypic characterization of glycopeptide, aminoglycoside and macrolide resistance among clinical isolates of Enterococcus faecalis: a multicenter based study. BMC Res Notes 2019; 12:292. [PMID: 31133071 PMCID: PMC6537152 DOI: 10.1186/s13104-019-4339-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/22/2019] [Indexed: 11/12/2022] Open
Abstract
Objectives Enterococcus faecalis as part of the normal floras of human gastrointestinal and genitourinary tracts are an important cause of nosocomial infections. The present study aimed to investigate the prevalence of genes encoding antimicrobial resistance and genetic relatedness of clinical isolates of E. faecalis among Iranian hospitalized patients. Results Antibiotic susceptibility testing results indicated that 53 (22.8%) out of 232 E. faecalis isolates were vancomycin resistant (MIC ≥ 256 μg/ml). All of the 53 vancomycin-resistant E. faecalis isolates carried the vanA and ermB genes; whereas aac (6′)-Ie aph (2″), msrA, and ermA gene were found in 96.2%, 30.2% and 3.8% of vancomycin-resistant isolates, respectively. ERIC-PCR typing revealed that 53 vancomycin-resistant isolates were classified into 14 ERIC types. In our results, the high level of resistance to gentamicin, erythromycin and vancomycin in enterococci isolates were mainly related to the presence of aac (6′)-Ie aph (2″), ermB and vanA genes, respectively. Meanwhile, ERIC-PCR analysis demonstrated that most of the evaluated isolates have a close genetic relatedness.
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Affiliation(s)
- Mehrdad Zalipour
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar Jarib St, Isfahan, Iran
| | - Bahram Nasr Esfahani
- Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyed Asghar Havaei
- Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Hezar Jarib St, Isfahan, Iran. .,Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
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Avery LM, Kuti JL, Weisser M, Egli A, Rybak MJ, Zasowski EJ, Arias CA, Contreras GA, Chong PP, Aitken SL, DiPippo AJ, Wang JT, Britt NS, Nicolau DP. Pharmacodynamic Analysis of Daptomycin-treated Enterococcal Bacteremia: It Is Time to Change the Breakpoint. Clin Infect Dis 2019. [PMID: 30188976 DOI: 10.1093/cid/ciy749.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Currently, there is debate over whether the daptomycin susceptibility breakpoint for enterococci (ie, minimum inhibitory concentration [MIC] ≤4 mg/L) is appropriate. In bacteremia, observational data support prescription of high doses (>8 mg/kg). However, pharmacodynamic targets associated with positive patient outcomes are undefined. METHODS Data were pooled from observational studies that assessed outcomes in daptomycin-treated enterococcal bacteremia. Patients who received an additional antienterococcal antibiotic and/or a β-lactam antibiotic at any time during treatment were excluded. Daptomycin exposures were calculated using a published population pharmacokinetic model. The free drug area under the concentration-time curve to MIC ratio (fAUC/MIC) threshold predictive of survival at 30 days was identified by classification and regression tree analysis and confirmed with multivariable logistic regression. Monte Carlo simulations determined the probability of target attainment (PTA) at clinically relevant MICs. RESULTS Of 114 patients who received daptomycin monotherapy, 67 (58.8%) were alive at 30 days. A fAUC/MIC >27.43 was associated with survival in low-acuity (n = 77) patients (68.9 vs 37.5%, P = .006), which remained significant after adjusting for infection source and immunosuppression (P = .026). The PTA for a 6-mg/kg/day (every 24 hours) dose was 1.5%-5.5% when the MIC was 4 mg/L (ie, daptomycin-susceptible) and 91.0%-97.9% when the MIC was 1 mg/L. CONCLUSIONS For enterococcal bacteremia, a daptomycin fAUC/MIC >27.43 was associated with 30-day survival among low-acuity patients. As pharmacodynamics for the approved dose are optimized only when MIC ≤1 mg/L, these data continue to stress the importance of reevaluation of the susceptibility breakpoint.
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Affiliation(s)
- Lindsay M Avery
- Center for Anti-infective Research and Development, Hartford Hospital, Connecticut
| | - Joseph L Kuti
- Center for Anti-infective Research and Development, Hartford Hospital, Connecticut
| | - Maja Weisser
- Division of Infectious Diseases and Hospital Epidemiology
| | - Adrian Egli
- Division of Clinical Microbiology, University Hospital Basel.,Applied Microbiology Research, University of Basel, Switzerland
| | - Michael J Rybak
- Anti-infective Research Laboratory, College of Pharmacy, School of Medicine, Division of Infectious Diseases, Wayne State University, Detroit, Michigan
| | - Evan J Zasowski
- Anti-infective Research Laboratory, College of Pharmacy, School of Medicine, Division of Infectious Diseases, Wayne State University, Detroit, Michigan.,Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy
| | - Cesar A Arias
- Center for Antimicrobial Resistance and Microbial Genomics and Division of Infectious Diseases, University of Texas Health Science Center, McGovern Medical School at Houston.,Center for Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston.,Molecular Genetics and Antimicrobial Resistance Unit, International Center for Microbial Genomics, Universidad El Bosque, Colombia
| | - German A Contreras
- Center for Antimicrobial Resistance and Microbial Genomics and Division of Infectious Diseases, University of Texas Health Science Center, McGovern Medical School at Houston
| | - Pearlie P Chong
- Division of Infectious Diseases, University of Texas Southwestern Medical Center, Dallas
| | - Samuel L Aitken
- Division of Pharmacy, University of Texas MD Anderson Cancer Center, Houston
| | - Adam J DiPippo
- Division of Pharmacy, University of Texas MD Anderson Cancer Center, Houston
| | - Jann-Tay Wang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei
| | - Nicholas S Britt
- Research Department, Dwight D. Eisenhower Veterans Affairs Medical Center, Leavenworth.,Department of Pharmacy Practice, University of Kansas School of Pharmacy
| | - David P Nicolau
- Center for Anti-infective Research and Development, Hartford Hospital, Connecticut.,Division of Infectious Diseases, Hartford Hospital, Connecticut
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Sacramento AG, Fernandes MR, Sellera FP, Dolabella SS, Zanella RC, Cerdeira L, Lincopan N. VanA-type vancomycin-resistant Enterococcus faecium ST1336 isolated from mussels in an anthropogenically impacted ecosystem. MARINE POLLUTION BULLETIN 2019; 142:533-536. [PMID: 31232334 DOI: 10.1016/j.marpolbul.2019.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/28/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
We report the occurrence and genomic features of multidrug-resistant vancomycin-resistant Enterococcus faecium vanA belonging to a novel sequence type (designated ST1336), carrying a Tn1546-like element, in marine brown mussels (Perna perna) from anthropogenically affected coastal waters of the Atlantic coast of Brazil, highlighting a potential source of dissemination for related ecosystems, with additional consequences for seafood safety and quality.
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Affiliation(s)
- Andrey G Sacramento
- Department of Morphology, Federal University of Sergipe, São Cristóvão, Brazil.
| | - Miriam R Fernandes
- Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Fábio P Sellera
- Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Silvio S Dolabella
- Department of Morphology, Federal University of Sergipe, São Cristóvão, Brazil
| | | | - Louise Cerdeira
- Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Nilton Lincopan
- Department of Clinical Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil; Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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An epidemiological and molecular study regarding the spread of vancomycin-resistant Enterococcus faecium in a teaching hospital in Bogotá, Colombia 2016. BMC Infect Dis 2019; 19:258. [PMID: 30876395 PMCID: PMC6419805 DOI: 10.1186/s12879-019-3877-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 03/05/2019] [Indexed: 11/10/2022] Open
Abstract
Background Enterococcus faecium is ranked worldwide as one of the top ten pathogens identified in healthcare-associated infections (HAI) and is classified as one of the high priority pathogens for research and development of new antibiotics worldwide. Due to molecular biology techniques’ higher costs, the approach for identifying and controlling infectious diseases in developing countries has been based on clinical and epidemiological perspectives. Nevertheless, after an abrupt vancomycin-resistant Enterococcus faecium dissemination in the Méderi teaching hospital, ending up in an outbreak, further measures needed to be taken into consideration. The present study describes the vancomycin-resistant Enterococcus faecium pattern within Colombian’s largest installed-bed capacity hospital in 2016. Methods Thirty-three vancomycin-resistant Enterococcus faecium isolates were recovered during a 5-month period in 2016. Multilocus variable-number tandem-repeat analysis was used for molecular typing to determine clonality amongst strains. A modified time-place-sequence algorithm was used to trace VREfm spread patterns during the outbreak period and estimate transmission routes. Results Four clonal profiles were identified. Chronological clonal profile follow-up suggested a transitional spread from profile “A” to profile “B”, returning to a higher prevalence of “A” by the end of the study. Antibiotic susceptibility indicated high-level vancomycin-resistance in most isolates frequently matching vanA gene identification. Discussion Transmission analysis suggested cross-contamination via healthcare workers. Despite epidemiological control of the outbreak, post-outbreak isolates were still being identified as having outbreak-related clonal profile (A), indicating reduction but not eradication of this clonality. This study supports the use of combined molecular and epidemiological strategies in an approach to controlling infectious diseases. It contributes towards a more accurate evaluation of the effectiveness of the epidemiological measures taken regarding outbreak control and estimates the main cause related to the spread of this microorganism. Electronic supplementary material The online version of this article (10.1186/s12879-019-3877-7) contains supplementary material, which is available to authorized users.
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Comparative Epidemiology of Vancomycin-Resistant Enterococci Colonization in an Acute-Care Hospital and Its Affiliated Intermediate- and Long-Term Care Facilities in Singapore. Antimicrob Agents Chemother 2018; 62:AAC.01507-18. [PMID: 30224534 DOI: 10.1128/aac.01507-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 09/07/2018] [Indexed: 12/27/2022] Open
Abstract
Vancomycin-resistant enterococci (VRE) are an important cause of nosocomial infections in acute-care hospitals (ACHs), intermediate-care facilities (ITCFs), and long-term care facilities (LTCFs). This study contemporaneously compared the epidemiology and risk factors for VRE colonization in different care settings in a health care network. We conducted a serial cross-sectional study in a 1,700-bed ACH and its six closely affiliated ITCFs and LTCFs in June and July of 2014 to 2016. Rectal swab or stool specimens were cultured for VRE. Multivariable logistic regression was used to assess for independent risk factors associated with VRE colonization. Of 5,357 participants, 523 (9.8%) were VRE colonized. VRE prevalence was higher in ACHs (14.2%) than in ITCFs (7.6%) and LTCFs (0.8%). Common risk factors between ACHs and ITCFs included prior VRE carriage, a longer duration of antibiotic therapy, surgery in the preceding 90 days, and the presence of a skin ulcer. Independent risk factors specific to ACH-admitted patients were prior methicillin-resistant Staphylococcus aureus carriage, a higher number of beds per room, prior proton pump inhibitor use, and a length of stay of >14 days. For ITCFs, a length of stay of >14 days was inversely associated with VRE colonization. Similarities and differences in risk factors for VRE colonization were observed between health care settings. VRE prevention efforts should target the respective high-risk patients.
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Proteomic Signatures of Clostridium difficile Stressed with Metronidazole, Vancomycin, or Fidaxomicin. Cells 2018; 7:cells7110213. [PMID: 30445773 PMCID: PMC6262375 DOI: 10.3390/cells7110213] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 12/12/2022] Open
Abstract
The anaerobic pathogen Clostridium difficile is of growing significance for the health care system due to its increasing incidence and mortality. As C. difficile infection is both supported and treated by antibiotics, a deeper knowledge on how antimicrobial agents affect the physiology of this important pathogen may help to understand and prevent the development and spreading of antibiotic resistant strains. As the proteomic response of a cell to stress aims at counteracting the harmful effects of this stress, it can be expected that the pattern of a pathogen’s responses to antibiotic treatment will be dependent on the antibiotic mechanism of action. Hence, every antibiotic treatment is expected to result in a specific proteomic signature characterizing its mode of action. In the study presented here, the proteomic response of C. difficile 630∆erm to vancomycin, metronidazole, and fidaxomicin stress was investigated on the level of protein abundance and protein synthesis based on 2D PAGE. The quantification of 425 proteins of C. difficile allowed the deduction of proteomic signatures specific for each drug treatment. Indeed, these proteomic signatures indicate very specific cellular responses to each antibiotic with only little overlap of the responses. Whereas signature proteins for vancomycin stress fulfil various cellular functions, the proteomic signature of metronidazole stress is characterized by alterations of proteins involved in protein biosynthesis and protein degradation as well as in DNA replication, recombination, and repair. In contrast, proteins differentially expressed after fidaxomicin treatment can be assigned to amino acid biosynthesis, transcription, cell motility, and the cell envelope functions. Notably, the data provided by this study hint also at so far unknown antibiotic detoxification mechanisms.
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Abstract
Enterococcus faecium has a highly variable genome prone to recombination and horizontal gene transfer. Here, we have identified a novel genetic island with an insertion locus and mobilization genes similar to those of staphylococcus cassette chromosome elements SCCmec This novel element termed the enterococcus cassette chromosome (ECC) element was located in the 3' region of rlmH and encoded large serine recombinases ccrAB similar to SCCmec Horizontal transfer of an ECC element termed ECC::cat containing a knock-in cat chloramphenicol resistance determinant occurred in the presence of a conjugative rep pLG1 plasmid. We determined the ECC::cat insertion site in the 3' region of rlmH in the E. faecium recipient by long-read sequencing. ECC::cat also mobilized by homologous recombination through sequence identity between flanking insertion sequence (IS) elements in ECC::cat and the conjugative plasmid. The ccrABEnt genes were found in 69 of 516 E. faecium genomes in GenBank. Full-length ECC elements were retrieved from 32 of these genomes. ECCs were flanked by attR and attL sites of approximately 50 bp. The attECC sequences were found by PCR and sequencing of circularized ECCs in three strains. The genes in ECCs contained an amalgam of common and rare E. faecium genes. Taken together, our data imply that ECC elements act as hot spots for genetic exchange and contribute to the large variation of accessory genes found in E. faecium IMPORTANCE Enterococcus faecium is a bacterium found in a great variety of environments, ranging from the clinic as a nosocomial pathogen to natural habitats such as mammalian intestines, water, and soil. They are known to exchange genetic material through horizontal gene transfer and recombination, leading to great variability of accessory genes and aiding environmental adaptation. Identifying mobile genetic elements causing sequence variation is important to understand how genetic content variation occurs. Here, a novel genetic island, the enterococcus cassette chromosome, is shown to contain a wealth of genes, which may aid E. faecium in adapting to new environments. The transmission mechanism involves the only two conserved genes within ECC, ccrAB Ent, large serine recombinases that insert ECC into the host genome similarly to SCC elements found in staphylococci.
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Uchiyama S, Dahesh S, Nizet V, Kessler J. Enhanced topical delivery of non-complexed molecular iodine for Methicillin-resistant Staphylococcus aureus decolonization. Int J Pharm 2018; 554:81-86. [PMID: 30395958 DOI: 10.1016/j.ijpharm.2018.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 10/29/2018] [Accepted: 11/02/2018] [Indexed: 02/05/2023]
Abstract
Staphylococcus aureus, a leading cause of serious human infections in both healthcare and community settings, is increasingly difficult to control due to expanding resistance to multiple antibiotic classes. Methicillin-resistant S. aureus (MRSA) strains have disseminated on a global scale and are associated with adverse patient outcomes, increased hospital stays, and significant economic costs to the healthcare system. A proximal step in S. aureus infection is colonization of the nasal mucosa, and effective strategies to decolonize high risk patients to reduce the risk of invasive infection and nosocomial spread represent an important clinical priority. With rising resistance to mupirocin, the most common antibiotic utilized for nasal MRSA decontamination, we are examining the use of pure molecular iodine (I2)-based formulations for this indication. Recently, an iodophor formulation of povidone-iodine (PVP-I) has shown significant promise for nasal MRSA decontamination by swabbing the anterior nares of patients in hospital settings, but the I2 concentration in this treatment is less than 0.01% of total iodine species present and like all providone-iodine formulations causes skin staining. Here we determine that a novel non-staining formulation of I2 combined with the safe organic emollient glycerin delivers high local concentrations of the active antimicrobial entity (I2) with minimal evaporative loss, exhibits activity at ∼1 part per million against MRSA and other important Gram-positive and -negative human pathogens. This formulation for I2 topical delivery produced similar reductions in mean bacterial burden and was associated with fewer treatment failures (<2-logfold reduction) than PVP-I in a murine model of MRSA nasal decontamination. Formulations of I2 in glycerin emollient merit further exploration as topical disinfectants for human medical indications.
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Affiliation(s)
- Satoshi Uchiyama
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0760, USA
| | - Samira Dahesh
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0760, USA
| | - Victor Nizet
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0760, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093-0760, USA.
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O'Gorman MA, Michaels MG, Kaplan SL, Otley A, Kociolek LK, Hoffenberg EJ, Kim KS, Nachman S, Pfefferkorn MD, Sentongo T, Sullivan JE, Sears P. Safety and Pharmacokinetic Study of Fidaxomicin in Children With Clostridium difficile-Associated Diarrhea: A Phase 2a Multicenter Clinical Trial. J Pediatric Infect Dis Soc 2018; 7:210-218. [PMID: 28575523 DOI: 10.1093/jpids/pix037] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/18/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Fidaxomicin is an approved therapy for Clostridium difficile-associated diarrhea (CDAD) in adults. The safety of fidaxomicin in children has not been reported. METHODS In this study (ClinicalTrials.gov identifier NCT01591863), pediatric patients with CDAD received twice-daily oral fidaxomicin at a dose of 16 mg/kg per day (up to 200 mg) for 10 days in an open-label study. Plasma and fecal samples were collected for pharmacokinetic assessments. The primary outcome measure was safety, which was assessed by adverse-event (AE), laboratory, and physical examination/vital-sign monitoring. Efficacy was determined through early and sustained clinical response rates (clinical response without recurrence of CDAD). RESULTS The study enrolled 40 patients (11 months to 17 years of age), many with underlying comorbidity, including neoplasm (23.7%), gastrointestinal disorder (78.9%), and history of CDAD (60.5%). Plasma fidaxomicin and OP-1118 (the major fidaxomicin metabolite) 3- to 5-hour postdose concentrations were 0.6 to 87.4 and 2.4 to 882.0 ng/mL, respectively, and no age-related trends were seen. Fecal fidaxomicin concentrations within 24 hours of the last dose averaged 3228 µg/g, and higher concentrations and greater variability in the youngest age group were found. AEs were reported in 73.7% of the patients; most of them were mild (44.7%) to moderate (21.1%) and were considered treatment-related in 15.8% of the patients. Overall, the early clinical response rate was 92.1%. The rate of sustained clinical response (clinical response without recurrence through 28 days after treatment) was 65.8% overall. CONCLUSIONS Fidaxomicin was well tolerated in children with CDAD and has a pharmacokinetic profile in children similar to that in adults. The clinical response rate was high.
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Affiliation(s)
- Molly A O'Gorman
- University of Utah School of Medicine, Primary Children's Hospital, Salt Lake City, Utah
| | - Marian G Michaels
- University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh of UPMC, Pennsylvania
| | | | | | | | | | - Kwang Sik Kim
- Johns Hopkins University, School of Medicine, Baltimore, Maryland
| | | | - Marian D Pfefferkorn
- Indiana University School of Medicine, Riley Hospital for Children, Indianapolis
| | - Timothy Sentongo
- University of Chicago Medicine, Comer Children's Hospital, Illinois
| | - Janice E Sullivan
- Kosair Charities Pediatric Clinical Research Unit, University of Louisville and Kosair Children's Hospital, Kentucky
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Morfin-Otero R, Perez-Gomez HR, Gonzalez-Diaz E, Esparza-Ahumada S, Rodriguez-Noriega E. Enterococci as Increasing Bacteria in Hospitals: Why Are Infection Control Measures Challenging for This Bacteria? CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2018. [DOI: 10.1007/s40506-018-0166-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gelman D, Beyth S, Lerer V, Adler K, Poradosu-Cohen R, Coppenhagen-Glazer S, Hazan R. Combined bacteriophages and antibiotics as an efficient therapy against VRE Enterococcus faecalis in a mouse model. Res Microbiol 2018; 169:531-539. [PMID: 29777835 DOI: 10.1016/j.resmic.2018.04.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/06/2018] [Accepted: 04/17/2018] [Indexed: 10/16/2022]
Abstract
Clinical applications of bacteriophage therapy have been recently gathering significant attention worldwide, used mostly as rescue therapy in cases of near-fatal antibiotic failure. Thus, clinically relevant in-vivo models presenting both short- and long-term implications of phage therapy given as rescue treatment for fulminant infections are of highest importance. In this study, a cocktail consisting of two lytic bacteriophages was used to evaluate the therapeutic efficacy of phage therapy as a rescue treatment for severe septic peritonitis in a mouse model. We established that a single injection of the bacteriophage cocktail was sufficient to completely reverse a 100% mortality trend caused by Vancomycin-Resistant Enterococcus faecalis, with significant improvement in both the clinical state and laboratory test results, and without harmful effects on the microbiome. The combination of bacteriophages with a suboptimal antibiotic regimen imparts an additional beneficial effect on the treatment success.
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Affiliation(s)
- Daniel Gelman
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel; The Military Track of Medicine, Faculty of Medicine, The Hebrew University - Hadassah School of Medicine, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel.
| | - Shaul Beyth
- Orthopedic Surgery Department, Hadassah Medical Center, Hadassah University Hospital, P.O.B 12000, Jerusalem, 91120, Israel.
| | - Vanda Lerer
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel.
| | - Karen Adler
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel.
| | - Ronit Poradosu-Cohen
- Department of Infectious Diseases of Sourasky Medical Center and Tel-Aviv University, Tel-Aviv, Israel.
| | - Shunit Coppenhagen-Glazer
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel.
| | - Ronen Hazan
- Institute of Dental Sciences, Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Campus, P.O.B 12272, Jerusalem, 91120, Israel.
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Oritavancin in vitro activity against gram-positive organisms from European and United States medical centers: results from the SENTRY Antimicrobial Surveillance Program for 2010-2014. Diagn Microbiol Infect Dis 2018; 91:199-204. [PMID: 29567128 DOI: 10.1016/j.diagmicrobio.2018.01.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 12/17/2022]
Abstract
The in vitro activity of oritavancin was assessed against 44,715 gram-positive pathogens causing infections in European and United States (US) hospitals (2010-2014). There were no substantive differences (>±2-fold dilution) in oritavancin MIC50 or MIC90 values for different species/organism groups over time or by region. Oritavancin (99.9% susceptible) showed modal MIC, MIC50, and MIC90 results of 0.03, 0.03, and 0.06-0.12 mg/L when tested against Staphylococcus aureus, regardless of methicillin susceptibility, year, or region. Coagulase-negative staphylococci from the US and Europe demonstrated equal MIC50 values for oritavancin (MIC50, 0.03 mg/L). Oritavancin inhibited 99.9% of Enterococcus faecalis and all E. faecium at ≤0.5 mg/L, including vancomycin-resistant isolates. Oritavancin exhibited MIC50 results of 0.03 and ≤0.008 mg/L when tested against β-hemolytic and viridans group streptococci isolates, respectively, regardless of geographical region. Oritavancin maintained potent activity in vitro against this contemporary collection of European and US gram-positive isolates over 5 years (2010-2014).
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Monticelli J, Knezevich A, Luzzati R, Di Bella S. Clinical management of non-faecium non-faecalis vancomycin-resistant enterococci infection. Focus on Enterococcus gallinarum and Enterococcus casseliflavus/flavescens. J Infect Chemother 2018; 24:237-246. [PMID: 29396199 DOI: 10.1016/j.jiac.2018.01.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 01/09/2018] [Indexed: 02/07/2023]
Abstract
Enterococcus gallinarum and Enterococcus casseliflavus/flavescens are enterococci intrinsically resistant to vancomycin belonging to the E. gallinarum group. They are responsible mainly for healthcare-associated infections, in particular bloodstream, urinary tract and surgical wound infections. Diseases due to these bacteria are significantly increasing worldwide, as they are prone to cause infection in patients with concurrent hepatobiliary or oncohematological disorders. Along with their distinguishing vancomycin resistance, due to a chromosomally-encoded VanC operon, their additional intrinsic resistance to many antibiotics other than glycopeptides limits the therapeutic choices. In addition, their intrinsic vancomycin resistance, unlike the vancomycin resistance of Enterococcus faecalis and Enterococcus faecium caused by transmissible plasmids, poses different infection control issues. We focused on the therapeutic and infection control issues of clinical syndromes caused by E. gallinarum and E. casseliflavus/flavescens. We propose therapeutic algorithms on bloodstream infections, endocarditis, central nervous system infections, endophthalmitis and urinary tract infections. The implementation of infection control measures in cases of E. gallinarum and E. casseliflavus/flavescens infection or colonization should be evaluated on a case-by-case basis, especially for epidemic outbreaks or for isolates supposed to harbor a potential transmissible vancomycin-resistance phenotype.
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Affiliation(s)
- Jacopo Monticelli
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
| | - Anna Knezevich
- Microbiology Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Strada di Fiume 447, 34149, Trieste, Italy.
| | - Roberto Luzzati
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
| | - Stefano Di Bella
- Infectious Diseases Division, Azienda Sanitaria Universitaria Integrata di Trieste (ASUITS), Piazza dell'Ospitale 1, 34129, Trieste, Italy.
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Niaz T, Shabbir S, Noor T, Abbasi R, Raza ZA, Imran M. Polyelectrolyte Multicomponent Colloidosomes Loaded with Nisin Z for Enhanced Antimicrobial Activity against Foodborne Resistant Pathogens. Front Microbiol 2018; 8:2700. [PMID: 29379490 PMCID: PMC5775282 DOI: 10.3389/fmicb.2017.02700] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 12/26/2017] [Indexed: 11/22/2022] Open
Abstract
Food grade micro- or nano-carrier systems (NCS) are being developed to improve the controlled release of antimicrobial agents. To augment the stability of liposomal NCS and to overcome the limitations associated with the use of free bacteriocin (nisin) in the food system, multi-component colloidosomes (MCCS) were developed by electrostatic interactions between anionic alginate and cationic chitosan (multilayer) around phospholipids based liposomes (core). Zeta-sizer results revealed the average diameter of 145 ± 2 nm, 596 ± 3 nm, and 643 ± 5 nm for nano-liposome (NL), chitosomes (chitosan coated NL) and MCCS, respectively. Zeta potential values of NCS varied from −4.37 ± 0.16 mV to 33.3 ± 6 mV, thus both chitosomes (CS) and MCCS were positively charged. Microstructure analysis by scanning electron microscope (SEM) revealed relatively higher size of MCCS with smooth and round morphology. TGA and DSC based experiments revealed that MCCS were thermally more stable than uncoated liposomes. Encapsulation efficiency of nisin in MCCS was observed to be 82.9 ± 4.1%, which was significantly higher than NL (56.5 ± 2.5%). FTIR analyses confirmed the cross-linking between sodium alginate and chitosan layer. Both qualitative (growth kinetics) and quantitative (colony forming unit) antimicrobial assays revealed that nisin loaded MCCS have superior potential to control resistant foodborne pathogens including Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis, (5.8, 5.4, and 6.1 Log CFUmL−1 reduction, respectively) as compared to free nisin, loaded NL or CS. Controlled release kinetics data fitted with Korsmeyer–Peppas model suggested that nisin release from MCCS followed Fickian diffusion. Cytotoxic studies on human blood cells and HepG2 cell lines revealed hemocompatibility and non-toxicity of MCCS. Thus, due to enhanced controlled release, stability and biocompatibility; these multi-component colloidosomes can be useful for incorporating antimicrobial agents into functional foods, beverages and pharmaceutical products to combat pathogenic and spoilage bacteria.
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Affiliation(s)
- Taskeen Niaz
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Saima Shabbir
- Department of Materials Science and Engineering, Institute of Space Technology, Islamabad, Pakistan
| | - Tayyaba Noor
- School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, Pakistan
| | - Rashda Abbasi
- Cancer Research, Institute of Biomedical and Genetic Engineering, Islamabad, Pakistan
| | - Zulfiqar A Raza
- Department of Applied Sciences, National Textile University, Faisalabad, Pakistan
| | - Muhammad Imran
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
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Pereira RVV, Carroll LM, Lima S, Foditsch C, Siler JD, Bicalho RC, Warnick LD. Impacts of feeding preweaned calves milk containing drug residues on the functional profile of the fecal microbiota. Sci Rep 2018; 8:554. [PMID: 29323259 PMCID: PMC5764986 DOI: 10.1038/s41598-017-19021-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/20/2017] [Indexed: 11/30/2022] Open
Abstract
Feeding drug residue-containing milk to calves is common worldwide and no information is currently available on the impact on the functional profile of the fecal microbiota. Our objective was to characterize the functional profile of the fecal microbiota of preweaned dairy calves fed raw milk with residual concentrations of antimicrobials commonly found in waste milk from birth to weaning. Calves were assigned to a controlled feeding trial being fed milk with no drug residues or milk with antibiotic residues. Fecal samples collected from each calf once a week starting at birth, prior to the first feeding in the trial, until 6 weeks of age. Antibiotic residues resulted in a significant difference in relative abundance of microbial cell functions, especially with genes linked with stress response, regulation and cell signaling, and nitrogen metabolism. These changes could directly impacts selection and dissemination of virulence and antimicrobial. Our data also identified a strong association between age in weeks and abundance of Resistance to Antibiotics and Toxic Compounds. Findings from this study support the hypothesis that drug residues, even at very low concentrations, impact the gut microbiota of calves and result in changes in the functional profile of microbial populations.
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Affiliation(s)
| | - Laura M Carroll
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Svetlana Lima
- College of Veterinary Medicine, University of California Davis, Davis, CA, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Carla Foditsch
- College of Veterinary Medicine, University of California Davis, Davis, CA, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Julie D Siler
- College of Veterinary Medicine, University of California Davis, Davis, CA, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Rodrigo Carvalho Bicalho
- College of Veterinary Medicine, University of California Davis, Davis, CA, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Lorin D Warnick
- College of Veterinary Medicine, University of California Davis, Davis, CA, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
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Maltezou HC, Elhadad D, Glikman D. Monitoring and managing antibiotic resistance in refugee children. Expert Rev Anti Infect Ther 2017; 15:1015-1025. [PMID: 29027495 DOI: 10.1080/14787210.2017.1392853] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The past decade the Middle East and Southeastern Europe have witnessed an enormous movement of refugees due to the Syrian war and conflicts in Asia and Africa. Although carriage of and infections with multi-drug resistant (MDR) pathogens in refugees have been reported, pediatric data are scarce. Areas covered: MDR bacterial carriage and infections, and MDR-tuberculosis (TB) in refugee children from 2010. Expert commentary: High MDR carriage rates in refugee children are attributed to high pre-civil war MDR rates, war-damaged infrastructure and healthcare systems, and poor hygiene conditions. Currently there are no international guidelines about MDR screening in refugee children. Given the medical importance of MDRs, challenging therapeutics and risk of importation in non/low-endemic countries, we recommend routine screening and contact isolation upon hospitalization of refugees. TB, including MDR-TB, is highly-endemic in many Asian and African countries, however, current data in refugee children are lacking. TB Screening in refugees is widely implemented but there is no consensus on methods and target populations. Coordinated TB detection and treatment, use of rapid molecular tests and drug-susceptibility testing, better access to healthcare, cross border TB care collaboration, and protection from deportation while on treatment should be integrated parts of TB control and prevention.
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Affiliation(s)
- Helena C Maltezou
- a Department for Interventions in Health Care Facilities , Hellenic Center for Disease Control and Prevention , Athens , Greece
| | - Dana Elhadad
- b The Faculty of Medicine in the Galilee , Bar-Ilan University , Safed , Israel
| | - Daniel Glikman
- b The Faculty of Medicine in the Galilee , Bar-Ilan University , Safed , Israel.,c Pediatric Infectious Diseases Unit , Galilee Medical Center , Nahariya , Israel
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Arhin FF, Seguin DL, Belley A, Moeck G. In vitro stepwise selection of reduced susceptibility to lipoglycopeptides in enterococci. Diagn Microbiol Infect Dis 2017; 89:168-171. [PMID: 28733126 DOI: 10.1016/j.diagmicrobio.2017.06.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/22/2017] [Accepted: 06/26/2017] [Indexed: 10/19/2022]
Abstract
The propensity of oritavancin to select for stably elevated oritavancin minimum inhibitory concentrations (MICs) was studied by serial passaging of strains in broth containing oritavancin for 20days. Seven clinical strains of Enterococcus faecalis and E. faecium were studied; they included vancomycin-susceptible and both VanA and VanB vancomycin-resistant isolates. Stepwise oritavancin selection yielded stably elevated oritavancin MICs in six of the seven strains, with MIC increases ranging from 4-32-fold. By comparison, stepwise selection with comparator agents dalbavancin (4- to >128-fold MIC increases), telavancin (4-8-fold MIC increases) and daptomycin (4-32-fold MIC increases) also yielded selectants with elevated MICs of the respective agents. Oritavancin selectants retained parental MICs of vancomycin, daptomycin, linezolid and rifampicin. Some, but not all of the oritavancin selectants also showed MIC increases to the lipoglycopeptides telavancin, dalbavancin and teicoplanin, suggesting that within the lipoglycopeptide class, different mechanisms of action may be elucidated.
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Affiliation(s)
- Francis F Arhin
- The Medicines Company, 7170 Frederick Banting, St. Laurent, Quebec, Canada, H4S 2A1.
| | - David Lalonde Seguin
- The Medicines Company, 7170 Frederick Banting, St. Laurent, Quebec, Canada, H4S 2A1
| | - Adam Belley
- The Medicines Company, 7170 Frederick Banting, St. Laurent, Quebec, Canada, H4S 2A1
| | - Gregory Moeck
- The Medicines Company, 7170 Frederick Banting, St. Laurent, Quebec, Canada, H4S 2A1
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Changed epidemiology during intra and interhospital spread of high-risk clones of vanA-containing Enterococcus in Brazilian hospitals. Diagn Microbiol Infect Dis 2017. [PMID: 28622949 DOI: 10.1016/j.diagmicrobio.2017.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We report changes in the molecular epidemiology of vanA-containing Enterococcus during the intra and interhospital spread of high-risk clones, in Southeastern Brazil. While VRE faecalis predominated during 1998 to 2006, a reversal has been observed in the last years, where VRE faecium belonging to ST114, ST203, ST412, ST478 and ST858 have become endemic.
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Agarwal V, Miles ZD, Winter JM, Eustáquio AS, El Gamal AA, Moore BS. Enzymatic Halogenation and Dehalogenation Reactions: Pervasive and Mechanistically Diverse. Chem Rev 2017; 117:5619-5674. [PMID: 28106994 PMCID: PMC5575885 DOI: 10.1021/acs.chemrev.6b00571] [Citation(s) in RCA: 246] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Naturally produced halogenated compounds are ubiquitous across all domains of life where they perform a multitude of biological functions and adopt a diversity of chemical structures. Accordingly, a diverse collection of enzyme catalysts to install and remove halogens from organic scaffolds has evolved in nature. Accounting for the different chemical properties of the four halogen atoms (fluorine, chlorine, bromine, and iodine) and the diversity and chemical reactivity of their organic substrates, enzymes performing biosynthetic and degradative halogenation chemistry utilize numerous mechanistic strategies involving oxidation, reduction, and substitution. Biosynthetic halogenation reactions range from simple aromatic substitutions to stereoselective C-H functionalizations on remote carbon centers and can initiate the formation of simple to complex ring structures. Dehalogenating enzymes, on the other hand, are best known for removing halogen atoms from man-made organohalogens, yet also function naturally, albeit rarely, in metabolic pathways. This review details the scope and mechanism of nature's halogenation and dehalogenation enzymatic strategies, highlights gaps in our understanding, and posits where new advances in the field might arise in the near future.
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Affiliation(s)
- Vinayak Agarwal
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
| | - Zachary D. Miles
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego
| | | | - Alessandra S. Eustáquio
- College of Pharmacy, Department of Medicinal Chemistry & Pharmacognosy and Center for Biomolecular Sciences, University of Illinois at Chicago
| | - Abrahim A. El Gamal
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
| | - Bradley S. Moore
- Center for Oceans and Human Health, Scripps Institution of Oceanography, University of California, San Diego
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego
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Khalifa L, Shlezinger M, Beyth S, Houri-Haddad Y, Coppenhagen-Glazer S, Beyth N, Hazan R. Phage therapy against Enterococcus faecalis in dental root canals. J Oral Microbiol 2016; 8:32157. [PMID: 27640530 PMCID: PMC5027333 DOI: 10.3402/jom.v8.32157] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/13/2016] [Accepted: 07/27/2016] [Indexed: 12/16/2022] Open
Abstract
Antibiotic resistance is an ever-growing problem faced by all major sectors of health care, including dentistry. Recurrent infections related to multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, and vancomycin-resistant enterococci (VRE) in hospitals are untreatable and question the effectiveness of notable drugs. Two major reasons for these recurrent infections are acquired antibiotic resistance genes and biofilm formation. None of the traditionally known effective techniques have been able to efficiently resolve these issues. Hence, development of a highly effective antibacterial practice has become inevitable. One example of a hard-to-eradicate pathogen in dentistry is Enterococcus faecalis, which is one of the most common threats observed in recurrent root canal treatment failures, of which the most problematic to treat are its biofilm-forming VRE strains. An effective response against such infections could be the use of bacteriophages (phages). Phage therapy was found to be highly effective against biofilm and multidrug-resistant bacteria and has other advantages like ease of isolation and possibilities for genetic manipulations. The potential of phage therapy in dentistry, in particular against E. faecalis biofilms in root canals, is almost unexplored. Here we review the efforts to develop phage therapy against biofilms. We also focus on the phages isolated against E. faecalis and discuss the possibility of using phages against E. faecalis biofilm in root canals.
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Affiliation(s)
- Leron Khalifa
- Institute of Dental Science, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Mor Shlezinger
- Department of Prosthodontics, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Shaul Beyth
- Orthopedic Surgery Complex, Hadassah University Hospital, Jerusalem, Israel
| | - Yael Houri-Haddad
- Department of Prosthodontics, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Shunit Coppenhagen-Glazer
- Institute of Dental Science, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Nurit Beyth
- Department of Prosthodontics, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel
| | - Ronen Hazan
- Institute of Dental Science, The Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel;
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