ddcP, pstB, and excess D-lactate impact synergism between vancomycin and chlorhexidine against Enterococcus faecium 1,231,410

AbstractVancomycin-resistant enterococci (VRE) are important nosocomial pathogens that cause life-threatening infections. To control hospital-associated infections, skin antisepsis and bathing utilizing chlorhexidine is recommended for VRE patients in acute care hospitals. Previously, we reported that exposure to inhibitory chlorhexidine levels induced the expression of vancomycin resistance genes in VanA-type Enterococcus faecium. However, vancomycin susceptibility actually increased for VanA-type E. faecium in the presence of chlorhexidine. Hence, a synergistic effect of the two antimicrobials was observed. In this study, we used multiple approaches to investigate the mechanism of synergism between chlorhexidine and vancomycin in the VanA-type VRE strain E. faecium 1,231,410. We generated clean deletions of 7 of 11 pbp, transpeptidase, and carboxypeptidase genes in this strain (ponA, pbpF, pbpZ, pbpA, ddcP, ldtfm, and vanY). Deletion of ddcP, encoding a membrane-bound carboxypeptidase, altered the synergism phenotype. Furthermore, using in vitro evolution, we isolated a spontaneous synergy escaper mutant and utilized whole genome sequencing to determine that a mutation in pstB, encoding an ATPase of phosphate-specific transporters, also altered synergism. Finally, addition of excess D-lactate, but not D-alanine, enhanced synergism. Overall, our work identified factors that alter chlorhexidine-induced vancomycin resensitization in a model VanA-type VRE strain.

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ddcP, pstB, and excess D-lactate impact synergism between vancomycin and chlorhexidine against Enterococcus faecium 1,231,410

PLoS ONE ◽

10.1371/journal.pone.0249631 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0249631

Author(s):

Pooja Bhardwaj ◽

Moutusee Z. Islam ◽

Christi Kim ◽

Uyen Thy Nguyen ◽

Kelli L. Palmer

Keyword(s):

Enterococcus Faecium ◽

Whole Genome ◽

Vancomycin Resistant Enterococci ◽

Control Hospital ◽

Skin Antisepsis ◽

Life Threatening ◽

Membrane Bound ◽

Vancomycin Resistant ◽

Hospital Associated Infections

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that cause life-threatening infections. To control hospital-associated infections, skin antisepsis and bathing utilizing chlorhexidine is recommended for VRE patients in acute care hospitals. Previously, we reported that exposure to inhibitory chlorhexidine levels induced the expression of vancomycin resistance genes in VanA-type Enterococcus faecium. However, vancomycin susceptibility actually increased for VanA-type E. faecium in the presence of chlorhexidine. Hence, a synergistic effect of the two antimicrobials was observed. In this study, we used multiple approaches to investigate the mechanism of synergism between chlorhexidine and vancomycin in the VanA-type VRE strain E. faecium 1,231,410. We generated clean deletions of 7 of 11 pbp, transpeptidase, and carboxypeptidase genes in this strain (ponA, pbpF, pbpZ, pbpA, ddcP, ldtfm, and vanY). Deletion of ddcP, encoding a membrane-bound carboxypeptidase, altered the synergism phenotype. Furthermore, using in vitro evolution, we isolated a spontaneous synergy escaper mutant and utilized whole genome sequencing to determine that a mutation in pstB, encoding an ATPase of phosphate-specific transporters, also altered synergism. Finally, addition of excess D-lactate, but not D-alanine, enhanced synergism to reduce vancomycin MIC levels. Overall, our work identified factors that alter chlorhexidine and vancomycin synergism in a model VanA-type VRE strain.

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Impact of Daptomycin Dose Exposure Alone or in Combination with β-Lactams or Rifampin against Vancomycin-Resistant Enterococci in an In Vitro Biofilm Model

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02074-19 ◽

2020 ◽

Vol 64 (5) ◽

Cited By ~ 1

Author(s):

Seyedehameneh Jahanbakhsh ◽

Nivedita B. Singh ◽

Juwon Yim ◽

Razieh Kebriaei ◽

Jordan R. Smith ◽

...

Keyword(s):

Bactericidal Activity ◽

Enterococcus Faecium ◽

Biofilm Reactor ◽

Content Type ◽

Biofilm Model ◽

Vancomycin Resistant Enterococci ◽

Dosing Regimens ◽

Vancomycin Resistant ◽

Reactor Models

ABSTRACT Enterococcus faecium strains are commonly resistant to vancomycin and β-lactams. In addition, E. faecium often causes biofilm-associated infections and these infections are difficult to treat. In this context, we investigated the activity of dosing regimens using daptomycin (DAP) (8, 10, 12, and 14 mg/kg of body weight/day) alone and in combination with ceftaroline (CPT), ampicillin (AMP), ertapenem (ERT), and rifampin (RIF) against 2 clinical strains of biofilm-producing vancomycin-resistant Enterococcus faecium (VREfm), namely, strains S447 and HOU503, in an in vitro biofilm model. HOU503 harbors common LiaS and LiaR substitutions, whereas S447 lacks mutations associated with the LiaFSR pathway. MIC results demonstrated that both strains were susceptible to DAP and resistant to CPT, AMP, ERT, and RIF. The 168-h pharmacokinetic/pharmacodynamic (PK/PD) CDC biofilm reactor models (simulating human antibiotic exposures) were used with titanium and polyurethane coupons to evaluate the efficacy of antibiotic combinations. DAP 12 and 14 achieved bactericidal activity against S447 but lacked such effect against HOU503. Addition of ERT and RIF enhanced DAP activity, allowing DAP 8 and 10 plus ERT or RIF to produce bactericidal activity against both strains at 168 h. While DAP 8 and 10 plus CPT improved killing, they did not reach bactericidal reduction against S447. Combination of AMP, CPT, ERT, or RIF resulted in enhanced and bactericidal activity for DAP against HOU503 at 168 h. Our data provide further support for the use of combinations of DAP with AMP, ERT, CPT, and RIF in infections caused by biofilm producing VREfm. Further research involving DAP combinations against biofilm-producing enterococci is warranted.

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In Vitro Activities of LY333328 and Comparative Agents against Nosocomial Gram-Positive Pathogens Collected in a 1997 Global Surveillance Study

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.5.1370-1374.2000 ◽

2000 ◽

Vol 44 (5) ◽

pp. 1370-1374 ◽

Cited By ~ 41

Author(s):

Michael L. Zeckel ◽

David A. Preston ◽

Bradley S. Allen

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Enterococcus Faecalis ◽

Enterococcus Faecium ◽

Vitro Activity ◽

In Vitro Activity ◽

Gram Positive ◽

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant

ABSTRACT The in vitro activity of LY333328 was evaluated for 1,479 nosocomial gram-positive pathogens isolated in 12 countries during 1997. LY333328 MICs at which 90% of the isolates tested were inhibited for Enterococcus faecalis (n = 351),Enterococcus faecium (n = 100),Staphylococcus aureus (n = 593), coagulase-negative Staphylococcus species (n = 325), and Streptococcus pneumoniae(n = 110) were 1, 1, 2, 2, and 0.015 μg/ml, respectively. LY333328 demonstrated potent activity against isolates of vancomycin-resistant enterococci, oxacillin-resistant staphylococci, and penicillin-resistant pneumococci.

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Efficacy of hand disinfectants against vancomycin-resistant enterococci in vitro

Journal of Hospital Infection ◽

10.1053/jhin.1998.0559 ◽

1999 ◽

Vol 42 (2) ◽

pp. 143-150 ◽

Cited By ~ 54

Author(s):

G. Kampf ◽

M. Höfer ◽

C. Wendt

Keyword(s):

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant

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In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.6.2498-2500.2005 ◽

2005 ◽

Vol 49 (6) ◽

pp. 2498-2500 ◽

Cited By ~ 7

Author(s):

Eun Jeong Yoon ◽

Yeong Woo Jo ◽

Sung Hak Choi ◽

Tae Ho Lee ◽

Jae Keol Rhee ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Streptococcus Pneumoniae ◽

Gram Positive ◽

Methicillin Resistant ◽

Gram Positive Bacteria ◽

Vancomycin Resistant Enterococci ◽

Infection Models ◽

Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

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The in-Vitro Activity of LY333328, a New Glycopeptide, against Clinical Isolates of Vancomycin-Resistant Enterococci

Streptococci and the Host - Advances in Experimental Medicine and Biology ◽

10.1007/978-1-4899-1825-3_115 ◽

1997 ◽

pp. 483-485

Author(s):

Monica Kirk ◽

Robert L. R. Hill ◽

Mark W. Casewell ◽

David Beighton

Keyword(s):

Vitro Activity ◽

Clinical Isolates ◽

In Vitro Activity ◽

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant

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Rapid in vivo development of resistance to daptomycin in vancomycin-resistant Enterococcus faecium due to genomic rearrangements

10.1101/2021.09.24.461763 ◽

2021 ◽

Author(s):

Sarah Mollerup ◽

Christine Elmeskov ◽

Heidi Gumpert ◽

Mette Pinholt ◽

Tobias Steen Sejersen ◽

...

Keyword(s):

Cell Wall ◽

Enterococcus Faecium ◽

Chromosomal Rearrangements ◽

Resistance Mechanisms ◽

Resistant Isolate ◽

Wall Structure ◽

Whole Genome ◽

Cyclic Lipopeptide ◽

Vancomycin Resistant

AbstractBackgroundDaptomycin is a cyclic lipopeptide used in the treatment of vancomycin-resistant Enterococcus faecium (VREfm). However, the development of daptomycin-resistant VREfm challenges the treatment of nosocomial VREfm infections. Resistance mechanisms of daptomycin are not fully understood. Here we analysed the genomic changes leading to a daptomycin-susceptible VREfm isolate becoming resistant after 40 days of daptomycin and linezolid combination therapy.MethodsThe two isogenic VREfm isolates (daptomycin-susceptible and daptomycin-resistant) were analysed using whole genome sequencing with Illumina and Nanopore.ResultsWhole genome comparative analysis identified the loss of a 46.5 kb fragment and duplication of a 29.7 kb fragment in the daptomycin-resistant isolate, with many implicated genes involved in cell wall synthesis. Two plasmids of the daptomycin-susceptible isolate were also found integrated in the chromosome of the resistant isolate. One nonsynonymous SNP in the rpoC gene was identified in the daptomycin-resistant isolate.ConclusionsDaptomycin resistance developed through chromosomal rearrangements leading to altered cell wall structure. Such novel types of resistance mechanisms can only be identified by comparing closed genomes of isogenic isolates.

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Evaluation of a vanA-Specific PCR Assay for Detection of Vancomycin-Resistant Enterococcus faecium during a Hospital Outbreak

Journal of Clinical Microbiology ◽

10.1128/jcm.37.10.3348-3349.1999 ◽

1999 ◽

Vol 37 (10) ◽

pp. 3348-3349 ◽

Cited By ~ 16

Author(s):

Michel Roger ◽

Marie-Claude Faucher ◽

Pierre Forest ◽

Pierre St-Antoine ◽

François Coutlée

Keyword(s):

Enterococcus Faecium ◽

Pcr Assay ◽

Culture Methods ◽

Agar Culture ◽

Enrichment Broth ◽

Specific Pcr ◽

Hospital Outbreak ◽

Vancomycin Resistant Enterococci ◽

Vancomycin Resistant ◽

Specific Pcr Assay

We investigated the use of PCR as an alternative to culture of fecal samples for detection of vanA-containingEnterococcus faecium during a recent hospital outbreak. Rectal swabs collected consecutively from 223 patients were analyzed by culture with and without enrichment broth and byvanA-specific PCR of enrichment broth samples. Fifty-five specimens were positive for vanA-containing E. faecium by at least one method. The sensitivities of thevanA-specific PCR assay and agar culture with and without enrichment broth were 94.5, 98, and 89%, respectively. All three methods were 100% specific. Final results were obtained much more rapidly by PCR (within 24 to 30 h of specimen submission) than by the culture methods (4 to 5 days). Thus, PCR is an accurate and rapid alternative to culture for detection of vancomycin-resistant enterococci during hospital outbreaks.

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