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1.
Microb Drug Resist ; 28(3): 267-273, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34748415

ABSTRACT

Vancomycin is widely used for treatment of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) leading to an increasing appearance of low-level vancomycin-resistant isolates called heterogeneous vancomycin-intermediate S. aureus (hVISA). The mechanism of vancomycin tolerance in hVISA is still unclear. This study aimed to investigate the fatty acid compositions of S. aureus isolates under the stress environment with vancomycin. The different responses of hVISA and vancomycin-susceptible S. aureus (VSSA) may lead to more understanding the mechanism. The bacterial lipid profiles were tested three times from three extractions of each isolate cultured on tryptic soy agar (TSA) and TSA with vancomycin. Of the 30 MRSA isolates studied, 13, 12, and 5 isolates were VSSA, hVISA, and VISA, respectively. The analysis of bacterial lipid profiles showed that under vancomycin stress, there was a reduction of straight chain fatty acids (SCFAs) in VSSA isolates but an increase in branched chain fatty acids (BCFAs). In contrast, the hVISA group exhibited an increase only in the BCFAs but not in SCFAs. Of interest, vancomycin had no effect on either BCFAs or SCFAs of the VISA cells. This study provided information of bacterial adaptation during stress with vancomycin that may be helpful to overcome the resistant bacteria.


Subject(s)
Fatty Acids/biosynthesis , Methicillin-Resistant Staphylococcus aureus/drug effects , Staphylococcus aureus/drug effects , Vancomycin Resistance/physiology , Vancomycin/pharmacology
3.
PLoS One ; 14(12): e0226101, 2019.
Article in English | MEDLINE | ID: mdl-31830083

ABSTRACT

Vancomycin resistant enterococci (VRE) belong to the most common causes of nosocomial infections worldwide. It has been reported that use of the glycopeptide growth promoter avoparcin selected for a significant livestock-reservoir of VRE in many European countries, including Norway. However, although avoparcin was banned as a feed-additive in 1995, VRE have for unknown reasons consistently been reported in samples from Norwegian broilers. When avoparcin was banned, broiler-feed was supplemented with the polyether ionophore narasin in order to control the diseases coccidiosis and the frequent sequela necrotic enteritis. A potential link between transferrable vancomycin resistance and reduced susceptibility to narasin was recently reported. The use of narasin as a feed additive was abolished by the Norwegian broiler industry in 2016 and since then, broilers have been reared without in-feed antibacterial supplements. In this study, we demonstrate that all VRE isolates from Norwegian broilers collected in 2006-2014 displayed reduced susceptibility to narasin. Surveillance data collected two years after the narasin abolishment show a significant reduction in VRE, below the detection limit of the surveillance method, and a concurrent marked reduction in Enterococcus faecium with reduced susceptibility to narasin. The significant decline of E. faecium with reduced susceptibility to these antimicrobial compounds also coincided with an increased focus on cleaning and disinfection between broiler flocks. Furthermore, data from a controlled in vivo experiment using Ross 308 broilers indicate that the proportion of E. faecium with reduced susceptibility to narasin was heavily reduced in broilers fed a narasin-free diet compared to a diet supplemented with narasin. Our results are consistent with that the abolishment of this feed additive, possibly in combination with the increased focus on cleaning and disinfection, has had a substantial impact on the occurrence of VRE in the Norwegian broiler population.


Subject(s)
Chickens/microbiology , Drug Resistance, Multiple, Bacterial , Enterococcus faecium , Food Industry/organization & administration , Gram-Positive Bacterial Infections/epidemiology , Infection Control/organization & administration , Vancomycin-Resistant Enterococci , Animals , Anti-Bacterial Agents/pharmacology , Antimicrobial Stewardship/organization & administration , Antimicrobial Stewardship/standards , Enterococcus faecium/isolation & purification , Food Industry/standards , Food Industry/trends , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/prevention & control , Gram-Positive Bacterial Infections/veterinary , Infection Control/standards , Infection Control/trends , Microbial Sensitivity Tests , Norway/epidemiology , Poultry Diseases/epidemiology , Poultry Diseases/microbiology , Poultry Diseases/prevention & control , Pyrans/pharmacology , Vancomycin Resistance/physiology , Vancomycin-Resistant Enterococci/isolation & purification
4.
BMC Geriatr ; 19(1): 377, 2019 12 27.
Article in English | MEDLINE | ID: mdl-31881861

ABSTRACT

BACKGROUND: In the context of an aging population, identifying risk factors for Vancomycin-resistant enterococci (VRE), specific to older people, is important. However, if age is a known risk factor for VRE infection, a limited number of studies have focused on older patients. This study aimed to identify potential risk factors for VRE acquisition in a population aged 65 years and older, during a large VRE outbreak that occurred in a teaching hospital in Lyon, France, from December 2013 to July 2014. METHODS: The present retrospective, multi-center, descriptive, and analytical study used part of a previous cohort, and included only a sub-group of patients aged 65 years and older. The analysis of the factors included in the original study was completed with factors more specific to geriatric patients. Inclusion criteria were patients aged 65 years and older, in contact with a VRE index patient. Patients were screened by rectal swabs. Univariate and multivariate logistic regression analyses were performed. RESULTS: A total of 180 VRE contacts were included and 18 patients became carriers. Multivariate analysis showed that risk factors for VRE acquisition in older people included major contact type (RR: 5.31, 95%CI [1.33; 21.19]), number of antibiotics used (RR: 1.36, 95%CI [1.04; 1.76]), a score of McCabe = 2 (RR: 116.39, 95%CI [5.52; 2455.98]), ethylism (RR: 5.50, 95%CI [1.49; 20.25]), and dementia (RR: 7.50, 95%CI [1.89; 29.80]). CONCLUSIONS: This study was able to demonstrate risk factors for VRE acquisition in older people. These risk factors should be taken into account when in the presence of older people in a VRE infected unit.


Subject(s)
Aging/drug effects , Aging/physiology , Disease Outbreaks/prevention & control , Vancomycin-Resistant Enterococci/drug effects , Vancomycin-Resistant Enterococci/physiology , Vancomycin/pharmacology , Aged , Aged, 80 and over , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cohort Studies , Cross Infection/epidemiology , Female , France/epidemiology , Gram-Positive Bacterial Infections , Humans , Male , Retrospective Studies , Risk Factors , Vancomycin/therapeutic use , Vancomycin Resistance/drug effects , Vancomycin Resistance/physiology
5.
BMC Microbiol ; 19(1): 153, 2019 07 05.
Article in English | MEDLINE | ID: mdl-31277575

ABSTRACT

BACKGROUND: Staphylococcus aureus remains a medical challenge in the treatment of bacterial infections. It has acquired resistance to commonly used antibiotics, and to those considered to be the last weapons in treating staphylococcal infections, such as vancomycin. Studies have revealed that S. aureus is capable of mounting a rapid response to antibiotics that target cell wall peptidoglycan biosynthesis, such as ß-lactams and vancomycin. The two-component system VraSR has been linked to the coordination of this response. VraS is a histidine kinase that undergoes autophosphorylation in the presence of signals elicited upon cell wall damage and it then transfers its phosphoryl group to VraR. VraR is a response regulator protein that functions as a transcription factor. Phosphorylation of VraR leads to its dimerization, which is required for optimum binding to its target promoters. Two-component systems have been targeted for the development of antibacterial agents. Deletion of the vraS or vraR gene has been shown to re-sensitize S. aureus to ß-lactams and vancomycin. RESULTS: In this study, we explored perturbation of the VraR phosphorylation-induced activation as a means to inhibit the VraSR-mediated signal transduction pathway. We show that dimerization of VraR is essential for the phosphorylation-induced activation of VraR. A single point mutation in the dimerization interface of VraR, in which Met13 was replaced by Ala, led to the inability of VraR to dimerize and to bind optimally to the target promoter. The consequences of these in vitro molecular deficiencies are equally dramatic in vivo. Complementation of a vraR deletion S. aureus strain with the vraRM13Ala mutant gene failed to induce the cell wall stress response. CONCLUSIONS: This study highlights the potential of targeting the phosphorylation-induced dimerization of VraR to disrupt the S. aureus cell wall stress response and in turn to re-sensitize S. aureus to ß-lactams and vancomycin.


Subject(s)
Bacterial Proteins/physiology , Cell Wall/metabolism , DNA-Binding Proteins/physiology , Staphylococcal Infections/microbiology , Staphylococcus aureus/pathogenicity , Phosphorylation , Protein Multimerization , Stress, Physiological , Vancomycin Resistance/physiology
6.
Anal Biochem ; 578: 29-35, 2019 08 01.
Article in English | MEDLINE | ID: mdl-31071297

ABSTRACT

The d,d-dipeptidase enzyme VanX is the main cause of vancomycin resistance in gram-positive bacteria because of hydrolysis of the D-Ala-D-Ala dipeptide used in cell-wall biosynthesis. Continuous assay of VanX has proven challenging due to lack of a chromophoric substrate. Here, we report a direct approach for continuous assay of VanX in vitro and in vivo from hydrolysis of D-Ala-D-Ala, based on the heat-rate changes measured with isothermal titration calorimetry (ITC). With the ITC approach, determination of kinetic parameters of VanX hydrolyzing D-Ala-D-Ala and the inhibition constant of d-cysteine inhibitor yielded KM of 0.10 mM, kcat of 11.5 s-1, and Ki of 18.8 µM, which are consistent with the data from ninhydrin/Cd(II) assays. Cell-based ITC studies demonstrated that the VanX expressed in E. coli and in clinical strain VRE was inhibited by d-cysteine with IC50 values of 29.8 and 28.6 µM, respectively. Also, the total heat from D-Ala-D-Ala (4 mM) hydrolysis decreases strongly (in absolute value) from 1.26 mJ for VRE to 0.031 mJ for E. faecalis, which is consistent with the large MIC value of vancomycin of 512 µg/mL for VRE and the much smaller value of 4 µg/mL for E. faecalis. The ITC approach proposed here could be applied to screen and evaluate small molecule inhibitors of VanX or to identify drug resistant bacteria.


Subject(s)
Bacterial Proteins , Calorimetry/methods , Enterococcus faecalis/metabolism , Escherichia coli/metabolism , Serine-Type D-Ala-D-Ala Carboxypeptidase , Vancomycin Resistance/physiology , Vancomycin-Resistant Enterococci/metabolism , Bacterial Proteins/analysis , Bacterial Proteins/metabolism , Hydrolysis , Kinetics , Serine-Type D-Ala-D-Ala Carboxypeptidase/analysis , Serine-Type D-Ala-D-Ala Carboxypeptidase/metabolism , Substrate Specificity
7.
Sci Rep ; 8(1): 8353, 2018 05 29.
Article in English | MEDLINE | ID: mdl-29844350

ABSTRACT

Multidrug-resistant enterococcal pathogens, especially vancomycin-resistant enterococci (VRE), are among the pathogens that require new antibiotic innovation. The colonization of the gut represents a major pathway by which VRE can cause infection and spread to other patients. In the current study, auranofin (FDA-approved rheumatoid arthritis drug) is evaluated for its potential use as a decolonizing agent for VRE. Auranofin was found to exert potent antimicrobial activity against a wide range of enterococcal clinical isolates with a minimum inhibitory concentration of 1 µg/mL. No resistant mutants could be developed against auranofin over the course of 14 passages. Auranofin was also found to exert potent anti-biofilm activity against VRE. Auranofin was superior to linezolid, the drug of choice for VRE infection treatment, in the in vivo mouse model. Auranofin significantly reduced the VRE burden in feces, cecum, and ileum contents after 8 days of treatment. Accordingly, this study provides valuable evidence that auranofin has significant promise as a novel gastrointestinal decolonizing agent for VRE.


Subject(s)
Auranofin/pharmacology , Vancomycin-Resistant Enterococci/drug effects , Animals , Anti-Bacterial Agents/pharmacology , Auranofin/therapeutic use , Biofilms/drug effects , Drug Repositioning/methods , Drug Resistance, Bacterial/physiology , Enterococcus/drug effects , Female , Intestines/drug effects , Linezolid/pharmacology , Mice , Mice, Inbred C57BL , Microbial Sensitivity Tests , Vancomycin/pharmacology , Vancomycin Resistance/physiology
8.
Article in English | MEDLINE | ID: mdl-29109158

ABSTRACT

Staphylococcus aureus is a major human pathogen whose infections are increasingly difficult to treat due to increased antibiotic resistance, including resistance to vancomycin. Vancomycin-intermediate S. aureus (VISA) strains develop resistance to vancomycin through adaptive changes that are incompletely understood. Central to this adaptation are metabolic changes that permit growth in the presence of vancomycin. To define the metabolic changes associated with adaptive resistance to vancomycin in S. aureus, the metabolomes of a vancomycin-sensitive and VISA strain pair isolated from the same patient shortly after vancomycin therapy began and following vancomycin treatment failure were analyzed. The metabolic adaptations included increases in acetogenesis, carbon flow through the pentose phosphate pathway, wall teichoic acid and peptidoglycan precursor biosynthesis, purine biosynthesis, and decreased tricarboxylic acid (TCA) cycle activity. The significance of these metabolic pathways for vancomycin-intermediate susceptibility was determined by assessing the synergistic potential of human-use-approved inhibitors of these pathways in combination with vancomycin against VISA strains. Importantly, inhibitors of amino sugar and purine biosynthesis acted synergistically with vancomycin to kill a diverse set of VISA strains, suggesting that combinatorial therapy could augment the efficacy of vancomycin even in patients infected with VISA strains.


Subject(s)
Adaptation, Physiological/physiology , Anti-Bacterial Agents/pharmacology , Fosfomycin/pharmacology , Mercaptopurine/pharmacology , Staphylococcus aureus/drug effects , Vancomycin Resistance/physiology , Vancomycin/pharmacology , Citric Acid Cycle/physiology , Drug Combinations , Drug Synergism , Humans , Microbial Sensitivity Tests , Pentose Phosphate Pathway/physiology , Staphylococcus aureus/isolation & purification
9.
Intern Med J ; 47(12): 1341-1351, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29224205

ABSTRACT

Healthcare-acquired infections (HAI) impact on patient care and have cost implications for the Australian healthcare system. The management of HAI is exacerbated by rising rates of antimicrobial resistance (AMR). Health-care workers and a contaminated hospital environment are increasingly implicated in the transmission and persistence of multi-resistant organisms (MRO), as well as other pathogens, such as Clostridium difficile. This has resulted in a timely focus on a range of HAI prevention actions. Core components include antimicrobial stewardship, to reduce overuse and ensure evidence-based antimicrobial use; infection prevention strategies, to control MRO - particularly methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus spp. (VRE) and, more recently, multi-resistant Gram-negative bacteria; enhanced institutional investment in hand hygiene; hospital cleaning and disinfection; and the development of prescribing guidelines and standards of care. AMR surveillance and comparisons of prescribing are useful feedback activities once effectively communicated to end users. Successful implementation of these strategies requires cultural shifts at local hospital level and, to tackle the serious threat posed by AMR, greater co-ordination at a national level. HAI prevention needs to be multi-modal, requires broad healthcare collaboration, and the strong support and accountability of all medical staff.


Subject(s)
Cross Infection/epidemiology , Cross Infection/prevention & control , Hospitals/standards , Infection Control/methods , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Australia/epidemiology , Clostridioides difficile/drug effects , Clostridioides difficile/physiology , Humans , Infection Control/standards , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/physiology , Staphylococcal Infections/epidemiology , Staphylococcal Infections/prevention & control , Vancomycin Resistance/drug effects , Vancomycin Resistance/physiology
10.
Article in English | MEDLINE | ID: mdl-28784674

ABSTRACT

There are limited therapeutic options to treat infections caused by vancomycin-resistant Enterococcus faecium (VREfm). The lipoglycopeptide oritavancin exhibits in vitro activity against this pathogen, although its utility against infections caused by VREfm has not been clinically established. In this study, the pharmacodynamic activity of free-drug levels associated with 12 mg/kg/day of daptomycin and a single 1,200-mg dose of oritavancin were determined against three VanA VREfm isolates in an in vitro pharmacokinetic/pharmacodynamic model.


Subject(s)
Anti-Bacterial Agents/pharmacology , Enterococcus faecium/drug effects , Glycopeptides/pharmacology , Glycopeptides/pharmacokinetics , Gram-Positive Bacterial Infections/drug therapy , Vancomycin-Resistant Enterococci/drug effects , Anti-Bacterial Agents/pharmacokinetics , Daptomycin/pharmacokinetics , Daptomycin/pharmacology , Enterococcus faecium/isolation & purification , Humans , Lipoglycopeptides , Microbial Sensitivity Tests , Vancomycin Resistance/physiology , Vancomycin-Resistant Enterococci/isolation & purification
11.
ACS Chem Biol ; 12(7): 1913-1918, 2017 07 21.
Article in English | MEDLINE | ID: mdl-28574692

ABSTRACT

Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.


Subject(s)
Adaptation, Physiological , Drug Resistance, Bacterial , Vancomycin-Resistant Enterococci/cytology , Vancomycin-Resistant Enterococci/drug effects , Vancomycin-Resistant Enterococci/metabolism , Vancomycin/pharmacology , Anti-Bacterial Agents/pharmacology , Artificial Cells/chemistry , Cell Wall/metabolism , Phenotype , Vancomycin/analogs & derivatives , Vancomycin Resistance/physiology
12.
Microb Pathog ; 109: 280-286, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28546117

ABSTRACT

Cronobacter sakazakii is an opportunistic pathogen responsible for necrotizing enterocolitis, meningitis and septicaemia especially to infant and neonate, with high lethality ranging in 40%-80%. This strain is able to survive in infant milk formula and possesses capability of pathogenicity and virulence, biofilm formation, and high resistance to elevated osmotic, low pH, heat, oxidation, and desiccasion. This study is aims to investigate the molecular characteristics of Cronobacter sakazakii BAA 894, including mechanisms of its invasion and adherence, biofilm formation, unusual resistance to environmental stress employing whole genome sequencing and comparative genomics. Results in this study suggest that numerous genes and pathways, such as LysM, Cyx system, luxS, vancomycin resistance pathway, insulin resistance pathway, and sod encoding superoxide dismutase for the survival of C. sakazakii in macrophages, contribute to pathogenicity and resistance to stressful environment of C. sakazakii BAA 894.


Subject(s)
Cronobacter sakazakii/genetics , Cronobacter sakazakii/pathogenicity , Genome, Bacterial/genetics , Virulence/genetics , Whole Genome Sequencing , Adhesins, Bacterial , Animals , Bacterial Outer Membrane Proteins/genetics , Bacterial Outer Membrane Proteins/metabolism , Biofilms/growth & development , Cronobacter sakazakii/metabolism , DNA, Bacterial , Enterobacteriaceae Infections/genetics , Enterobacteriaceae Infections/microbiology , Humans , Infant , Insulin Resistance/genetics , Insulin Resistance/physiology , Macrophages/microbiology , Milk , Peptide Hydrolases/genetics , Stress, Physiological/genetics , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Vancomycin Resistance/genetics , Vancomycin Resistance/physiology , Virulence Factors/genetics
13.
J Med Microbiol ; 66(4): 542-550, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28463660

ABSTRACT

PURPOSE: Meticillin-resistant Staphylococcus aureus (MRSA) biofilm formation in humans is of serious clinical concern. Previous in vitro studies have been performed with biofilms grown only on inorganic substrates; therefore, we investigated the vancomycin (VCM) resistance of MRSA biofilms grown on skin tissue. METHODOLOGY: We established a novel tissue substrate model, namely MRSA grown on segments of mouse skin tissue (dermal chips, DCs), and compared its resistance capacity against VCM with that of MRSA biofilms grown on plastic chips (PCs).Results/Key findings. For one MRSA isolate, we found that the VCM MIC was identical (1.56 µg ml-1) for planktonic cultures and for biofilms-formed on PCs (PC-BF), although the minimum bactericidal concentration (MBC) increased to 6.25 µg ml-1 in PC-BF. On the contrary, the MIC and MBC for biofilms formed on DCs (DC-BF) significantly increased (25 and 50 µg ml-1, respectively). Furthermore, the minimum biofilm-eradicating concentration was higher for DC-BF (100 µg ml-1) than for PC-BF (25 µg ml-1). Using six MRSA strains, we found that in PC-BF, the c.f.u. number decreased with increasing VCM concentration, whereas in DC-BF, it greatly increased until the MIC was reached, accompanied by the formation of large colonies, thicker bacterial walls and the presence of many mitotic cells. CONCLUSION: Our results indicate that the VCM resistance of MRSA was greater in DC-BF. We conclude that DCs may provide a specific environment for MRSA that enhances bacterial growth under cytotoxic VCM concentrations, and might be useful for the study of skin wound infections and the effects of antimicrobial drugs.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Methicillin-Resistant Staphylococcus aureus/drug effects , Vancomycin Resistance/physiology , Vancomycin/pharmacology , Animals , Female , Methicillin-Resistant Staphylococcus aureus/growth & development , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Mice , Mice, Inbred C57BL , Microbial Sensitivity Tests , Organ Culture Techniques , Skin/microbiology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology
14.
Neurosurgery ; 80(5): 746-753, 2017 May 01.
Article in English | MEDLINE | ID: mdl-28387851

ABSTRACT

BACKGROUND: Surgical site infection (SSI) following spine surgery is a morbid and expensive complication. The use of intrawound vancomycin is emerging as a solution to reduce SSI. The development of vancomycin-resistant pathogens is an understandable concern. OBJECTIVE: To determine the occurrence of vancomycin-resistant SSI in patients with and without use of intrawound vancomycin. METHODS: Patients undergoing elective spine surgery were dichotomized based on whether intrawound vancomycin was applied. Outcome was occurrence of SSI requiring return to the operating room within postoperative 90 days. The intrawound culture and vancomycin minimal inhibitory concentrations (MIC) were reviewed. Analyses were conducted to compare the pathogen profile and MIC for vancomycin in patients who received vancomycin and those who did not. RESULTS: Of the total 2802 patients, 43% (n = 1215) had intrawound vancomycin application during the index surgery. The use of vancomycin was associated with significantly lower deep SSI rates (1.6% [n = 20] vs 2.5% [n = 40], P = .02). The occurrence of Staphylococcus aureus SSI was significantly lower in the patients who had application of intrawound vancomycin (32% vs 65%, P = .003). None of the patients who had application of intrawound vancomycin powder, and subsequently developed an S aureus SSI, demonstrated pathogens with resistance to vancomycin. All patients had MIC < 2 µg/mL, the vancomycin susceptibility threshold. The occurrence of gram-negative SSI (28% vs 7%) and culture negative fluid collection (16% vs 5%) was higher in the vancomycin cohort. CONCLUSIONS: The use of intrawound vancomycin during the index spine surgery was protective against SSI following spine surgery. The application of intrawound vancomycin during index surgery does not appear to create vancomycin-resistant organisms in the event of an SSI.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Antibiotic Prophylaxis , Spinal Diseases/surgery , Surgical Wound Infection/drug therapy , Vancomycin Resistance/drug effects , Vancomycin/administration & dosage , Adult , Aged , Anti-Bacterial Agents/adverse effects , Antibiotic Prophylaxis/adverse effects , Elective Surgical Procedures/methods , Female , Humans , Male , Middle Aged , Spinal Diseases/diagnosis , Staphylococcal Infections/diagnosis , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Surgical Wound Infection/diagnosis , Vancomycin/adverse effects , Vancomycin Resistance/physiology
15.
Pharmacotherapy ; 37(5): 579-592, 2017 May.
Article in English | MEDLINE | ID: mdl-28273381

ABSTRACT

Enterococcus species are the second most common cause of nosocomial infections in the United States and are particularly concerning in critically ill patients with preexisting comorbid conditions. Rising resistance to antimicrobials that were historically used as front-line agents for treatment of enterococcal infections, such as ampicillin, vancomycin, and aminoglycosides, further complicates the treatment of these infections. Of particular concern are Enterococcus faecium strains that are associated with the highest rate of vancomycin resistance. The introduction of antimicrobial agents with specific activity against vancomycin-resistant Enterococcus (VRE) faecium including daptomycin, linezolid, quinupristin-dalfopristin, and tigecycline did not completely resolve this clinical dilemma. In this review, the mechanisms of action and resistance to currently available anti-VRE antimicrobial agents including newer agents such as oritavancin and dalbavancin will be presented. In addition, novel combination therapies including ß-lactams and fosfomycin, and the promising results from in vitro, animal studies, and clinical experience in the treatment of VRE faecium will be discussed.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/drug therapy , Vancomycin Resistance/drug effects , Vancomycin/administration & dosage , Animals , Cross Infection/diagnosis , Cross Infection/drug therapy , Cross Infection/epidemiology , Drug Therapy, Combination , Enterococcus faecium/isolation & purification , Gram-Positive Bacterial Infections/diagnosis , Gram-Positive Bacterial Infections/epidemiology , Humans , Teicoplanin/administration & dosage , Teicoplanin/analogs & derivatives , Vancomycin Resistance/physiology , Virginiamycin/administration & dosage
16.
J Oncol Pharm Pract ; 22(2): 212-8, 2016 Apr.
Article in English | MEDLINE | ID: mdl-25326010

ABSTRACT

BACKGROUND: The incidence and severity of vancomycin-resistant Enterococcus blood stream infections continue to rise and is a significant burden in the healthcare setting. Literature thus far is minimal regarding treatment outcomes in patients with malignancy and vancomycin-resistant Enterococcus bacteremia. Appropriate antibiotic selection is vital to treatment success due to high rates of resistance, limited antimicrobials and mortality in this patient population. We conducted this study to determine whether treatment outcomes differed between cancer patients treated with linezolid and those treated with daptomycin for vancomycin-resistant Enterococcus bacteremia. METHODS: This single-center, retrospective study included adult patients hospitalized on the oncology service with documented vancomycin-resistant Enterococcus faecium or Enterococcus faecalis bacteremia who received at least 48 h of either linezolid or daptomycin as primary treatment. RESULTS: A total of 65 patients were included in the analysis. Thirty-two patients received daptomycin as primary treatment, and 33 patients received linezolid as primary treatment. Twenty-six (76.5%) patients in the linezolid cohort versus 22 (71%) patients in the daptomycin cohort achieved microbiological cure (p = 0.6141). Median length of stay in days (30 vs. 42, p = 0.0714) and mortality (7/32 (20.6%) vs. 8/33 (25.8%), p = 0.6180) were also similar between the linezolid and daptomycin treated patients, respectively. CONCLUSION: No differences in microbiological cure, length of stay or mortality were identified between the groups. This study suggests that linezolid and daptomycin are each reasonable options for treating vancomycin-resistant Enterococcus bacteremia in oncology patients. Further prospective, randomized controlled trials are needed to assess the optimal treatment for vancomycin-resistant Enterococcus bacteremia in this patient population.


Subject(s)
Bacteremia/drug therapy , Daptomycin/therapeutic use , Enterococcus/drug effects , Linezolid/therapeutic use , Neoplasms/drug therapy , Vancomycin Resistance/drug effects , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Bacteremia/diagnosis , Bacteremia/epidemiology , Cohort Studies , Daptomycin/pharmacology , Enterococcus/physiology , Female , Humans , Linezolid/pharmacology , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/epidemiology , Retrospective Studies , Treatment Outcome , Vancomycin/pharmacology , Vancomycin/therapeutic use , Vancomycin Resistance/physiology
17.
Braz J Microbiol ; 46(3): 777-83, 2015.
Article in English | MEDLINE | ID: mdl-26413060

ABSTRACT

Vancomycin resistant Enterococcus faecium (VREF) ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs) of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patients who were admitted to the ICUs of the Mansoura University Hospitals (MUHs), and fulfilled the healthcare-associated infection (HAI) criteria. Susceptibility testing was determined using the disk diffusion method. The clonal relationships were evaluated with pulsed field gel electrophoresis (PFGE). Out of 52 E. faecium isolates, 12 (23.1%) were vancomycin resistant. The significant risk factors for the VREF infections were: transfer to the ICU from a ward, renal failure, an extended ICU stay and use of third-generation cephalosporins, gentamicin, or ciprofloxacin. PFGE with the 12 isolates showed 9 different patterns; 3 belonged to the same pulsotype and another 2 carried a second pulsotypes. The similar pulsotypes isolates were isolated from ICUs of one hospital (EICUs); however, all of the isolates from the other ICUs had different patterns. Infection control policy, in conjunction with antibiotic stewardship, is important to combat VREF transmission in these high-risk patients.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Cross Infection/epidemiology , Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/epidemiology , Vancomycin Resistance/physiology , Vancomycin-Resistant Enterococci/isolation & purification , Vancomycin/therapeutic use , Cephalosporins/therapeutic use , Ciprofloxacin/therapeutic use , Cross Infection/microbiology , DNA, Bacterial/genetics , Egypt/epidemiology , Enterococcus faecium/isolation & purification , Gentamicins/therapeutic use , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/microbiology , Humans , Infection Control/methods , Intensive Care Units , Microbial Sensitivity Tests , Prospective Studies , Renal Insufficiency , Risk Factors , Vancomycin-Resistant Enterococci/drug effects
18.
Braz. j. microbiol ; 46(3): 777-783, July-Sept. 2015. tab, ilus
Article in English | LILACS | ID: lil-755813

ABSTRACT

Vancomycin resistant Enterococcus faecium (VREF) ia an emerging and challenging nosocomial pathogen. This study aimed to determine the prevalence, risk factors and clonal relationships between different VREF isolates in the intensive care units (ICUs) of the university hospitals in our geographic location. This prospective study was conducted from July, 2012 until September, 2013 on 781 patients who were admitted to the ICUs of the Mansoura University Hospitals (MUHs), and fulfilled the healthcare-associated infection (HAI) criteria. Susceptibility testing was determined using the disk diffusion method. The clonal relationships were evaluated with pulsed field gel electrophoresis (PFGE). Out of 52 E. faecium isolates, 12 (23.1%) were vancomycin resistant. The significant risk factors for the VREF infections were: transfer to the ICU from a ward, renal failure, an extended ICU stay and use of third-generation cephalosporins, gentamicin, or ciprofloxacin. PFGE with the 12 isolates showed 9 different patterns; 3 belonged to the same pulsotype and another 2 carried a second pulsotypes. The similar pulsotypes isolates were isolated from ICUs of one hospital (EICUs); however, all of the isolates from the other ICUs had different patterns. Infection control policy, in conjunction with antibiotic stewardship, is important to combat VREF transmission in these high-risk patients.

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Subject(s)
Humans , Anti-Bacterial Agents/therapeutic use , Cross Infection/epidemiology , Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/epidemiology , Vancomycin Resistance/physiology , Vancomycin-Resistant Enterococci/isolation & purification , Vancomycin/therapeutic use , Cephalosporins/therapeutic use , Ciprofloxacin/therapeutic use , Cross Infection/microbiology , DNA, Bacterial/genetics , Egypt/epidemiology , Enterococcus faecium/isolation & purification , Gentamicins/therapeutic use , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/microbiology , Intensive Care Units , Infection Control/methods , Microbial Sensitivity Tests , Prospective Studies , Renal Insufficiency , Risk Factors , Vancomycin-Resistant Enterococci/drug effects
19.
Antimicrob Agents Chemother ; 59(5): 2926-9, 2015 May.
Article in English | MEDLINE | ID: mdl-25712360

ABSTRACT

The occurrence and diversity of vancomycin-resistant Enterococcus faecium (VREF) were investigated in 100 Danish broiler flocks 15 years after the avoparcin ban. VREF occurred in 47 flocks at low fecal concentrations detectable only by selective enrichment. Vancomycin resistance was prevalently associated with a transferable nontypeable plasmid lineage occurring in multiple E. faecium clones. Coselection of sequence type 842 by tetracycline use only partly explained the persistence of vancomycin resistance in the absence of detectable plasmid coresistance and toxin-antitoxin systems.


Subject(s)
Anti-Bacterial Agents/pharmacology , Enterococcus faecium/drug effects , Glycopeptides/pharmacology , Vancomycin Resistance/physiology , Animals , Chickens/microbiology , Enterococcus faecium/genetics , Plasmids/genetics , Vancomycin Resistance/genetics
20.
mBio ; 5(4): e01386-14, 2014 Jul 22.
Article in English | MEDLINE | ID: mdl-25053786

ABSTRACT

Three vancomycin-resistant streptococcal strains carrying vanG elements (two invasive Streptococcus agalactiae isolates [GBS-NY and GBS-NM, both serotype II and multilocus sequence type 22] and one Streptococcus anginosus [Sa]) were examined. The 45,585-bp elements found within Sa and GBS-NY were nearly identical (together designated vanG-1) and shared near-identity over an ~15-kb overlap with a previously described vanG element from Enterococcus faecalis. Unexpectedly, vanG-1 shared much less homology with the 49,321-bp vanG-2 element from GBS-NM, with widely different levels (50% to 99%) of sequence identity shared among 44 related open reading frames. Immediately adjacent to both vanG-1 and vanG-2 were 44,670-bp and 44,680-bp integrative conjugative element (ICE)-like sequences, designated ICE-r, that were nearly identical in the two group B streptococcal (GBS) strains. The dual vanG and ICE-r elements from both GBS strains were inserted at the same position, between bases 1328 and 1329, within the identical RNA methyltransferase (rumA) genes. A GenBank search revealed that although most GBS strains contained insertions within this specific site, only sequence type 22 (ST22) GBS strains contained highly related ICE-r derivatives. The vanG-1 element in Sa was also inserted within this position corresponding to its rumA homolog adjacent to an ICE-r derivative. vanG-1 insertions were previously reported within the same relative position in the E. faecalis rumA homolog. An ICE-r sequence perfectly conserved with respect to its counterpart in GBS-NY was apparent within the same site of the rumA homolog of a Streptococcus dysgalactiae subsp. equisimilis strain. Additionally, homologous vanG-like elements within the conserved rumA target site were evident in Roseburia intestinalis. Importance: These three streptococcal strains represent the first known vancomycin-resistant strains of their species. The collective observations made from these strains reveal a specific hot spot for insertional elements that is conserved between streptococci and different Gram-positive species. The two GBS strains potentially represent a GBS lineage that is predisposed to insertion of vanG elements.


Subject(s)
Bacterial Proteins/metabolism , Chromosomes, Bacterial/genetics , Streptococcus agalactiae/drug effects , Streptococcus agalactiae/genetics , Streptococcus anginosus/drug effects , Streptococcus anginosus/genetics , Bacterial Proteins/genetics , Molecular Sequence Data , Vancomycin Resistance/genetics , Vancomycin Resistance/physiology
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