Does vancomycin prescribing intervention affect vancomycin-resistant enterococcus infection and colonization in hospitals? A systematic review

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Riley Lee W

2007-04-01

Full Text Available Abstract Background Vancomycin resistant enterococcus (VRE is a major cause of nosocomial infections in the United States and may be associated with greater morbidity, mortality, and healthcare costs than vancomycin-susceptible enterococcus. Current guidelines for the control of VRE include prudent use of vancomycin. While vancomycin exposure appears to be a risk factor for VRE acquisition in individual patients, the effect of vancomycin usage at the population level is not known. We conducted a systematic review to determine the impact of reducing vancomycin use through prescribing interventions on the prevalence and incidence of VRE colonization and infection in hospitals within the United States. Methods To identify relevant studies, we searched three electronic databases, and hand searched selected journals. Thirteen studies from 12 articles met our inclusion criteria. Data were extracted and summarized for study setting, design, patient characteristics, types of intervention(s, and outcome measures. The relative risk, 95% confidence interval, and p-value associated with change in VRE acquisition pre- and post-vancomycin prescription interventions were calculated and compared. Heterogeneity in study results was formally explored by stratified analysis. Results No randomized clinical trials on this topic were found. Each of the 13 included studies used a quasi-experimental design of low hierarchy. Seven of the 13 studies reported statistically significant reductions in VRE acquisition following interventions, three studies reported no significant change, and three studies reported increases in VRE acquisition, one of which reported statistical significance. Results ranged from a reduction of 82.5% to an increase of 475%. Studies of specific wards, which included sicker patients, were more likely to report positive results than studies of an entire hospital including general inpatients (Fisher's exact test 0.029. The type of intervention

Prevalence and distribution of VRE (vancomycin resistant enterococci and VSE (vancomycin susceptible enterococci strains in the breeding environment

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Krzysztof Skowron

2016-06-01

Full Text Available [b]Introduction.[/b] Intensive animal production causes numerous problems. Facilities connected with animal maintenance not only cause environmental pollution, but also pose a great sanitary and epidemiological threat. Long-term use of antibiotics in animal production lead animal-borne microorganisms to develop multiple resistance mechanisms, transferred to the typical environmental bacteria. [b]Objective. [/b]The aim of this study was assessment of E. faecalis, E. faecium, E. durans and E. hirae prevalence in samples gathered from swine production sectors, and determination of the contribution of VRE (vancomycin resistant enterococci strains and their resistance. The degree of relationship between isolates of each species from genus Enterococcus was also determined. [b]Materials and method.[/b] 195 isolates were obtained, from which DNA was isolated. Genus identification was conducted with the primers specific to the 16S rRNA region, and identification of the species with primers specific to sequence of gene sodA in Multiplex PCR reaction. Resistance to vancomycin (6 μg×ml -1 was tested using a screening method on Muller Hinton Agar. To assess resistance type Multiplex PCR, amplifying products corresponding to genes VanA, VanB and VanC, was conducted. Genotyping was conducted using the PCR-RAPD method. [b]Results. [/b]Among the 195 isolates, 133 (68% belonged to E. hirae. The other species contributions were respectively: E. faecalis – 21%, E. durans – 8% and E. faecium – 3%. Only 2 isolates of E. hirae, being different strains, were resistant to vancomycin. Both were representing phenotype VanC1. 60 genetically different strains were defined. The possible contamination paths involved animal feed and spreading of excrements by slaughtered individuals or on personnel’s footwear. [b]Conclusions. [/b]The obtained results indicate a very low percentage of VRE strains in the tested piggery, resulting in a low health risk to piggery

Derivatives of a vancomycin-resistant Staphylococcus aureus strain isolated at Hershey Medical Center.

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Bozdogan, Bülent; Ednie, Lois; Credito, Kim; Kosowska, Klaudia; Appelbaum, Peter C

2004-12-01

Antimicrobial susceptibilities and genetic relatedness of the vancomycin-resistant Staphylococcus aureus strain (VRSA) isolated at Hershey, Pa. (VRSA Hershey), and its vancomycin-susceptible and high-level-resistant derivatives were studied and compared to 32 methicillin-resistant S. aureus strains (MRSA) isolated from patients and medical staff in contact with the VRSA patient. Derivatives of VRSA were obtained by subculturing six VRSA colonies from the original culture with or without vancomycin. Ten days of drug-free subculture caused the loss of vanA in two vancomycin-susceptible derivatives for which vancomycin MICs were 1 to 4 microg/ml. Multistep selection of three VRSA clones with vancomycin for 10 days increased vancomycin MICs from 32 to 1,024 to 2,048 microg/ml. MICs of teicoplanin, dalbavancin, and oritavancin were also increased from 4, 0.5, and 0.12 to 64, 1, and 32 microg/ml, respectively. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing analysis indicated that VRSA Hershey was the vanA-acquired variety of a common MRSA clone in our hospital with sequence type 5 (ST5). Three of five vancomycin-intermediate S. aureus strains tested from geographically different areas were also ST5, and the Michigan VRSA was ST371, a one-allele variant of ST5. Derivatives of VRSA Hershey had differences in PFGE profiles and the size of SmaI fragment that carries the vanA gene cluster, indicating instability of this cluster in VRSA Hershey. However induction with vancomycin increased glycopeptide MICs and stabilized the resistance.

Is the mazEF toxin-antitoxin system responsible for vancomycin resistance in clinical isolates of Enterococcus faecalis?

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Sadeghifard, Nourkhoda

2014-03-01

Full Text Available [english] The current study was conducted to investigate the relationship between vancomycin-resistant (VRE and the presence of toxin-antitoxin (TA system, which may be useful as target for novel antimicrobial therapy concepts. The susceptibility of was determined by MIC, and the presence of the TA system was evaluated by PCR. Among 200 isolates 39.5% showed resistance to vancomycin (VRE, while 60.5% were susceptible strains (VSE. The TA system was positive in all VRE isolates (100%, but less prevalent (38/121, 31.4% among the 121 VSE strains. In conclusion, our study demonstrated a positive relationship between the presence of vancomycin resistance and TA system. This observation may introduce therapeutic options against a novel antimicrobial target in enterococci.

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics

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Rathe, Mathias; Lise, Kristensen,; Ellermann-Eriksen, Svend

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics......Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics...

Our experiences with vancomycin-resistant enterococci in Jesenice General hospital

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Helena Ribič

2007-11-01

Full Text Available Background: Vancomycin-resistant enterococci (VRE present a great problem in health care, especially because of their resistance to many groups of antibiotics and because of the way of their spreading in health care and long-term care institutions. Genes responsible for resistance to vancomycin can be transmitted to other species of enterococci and also to other grampositive cocci, for example Staphylococcus aureus. Experts anticipate that failure to control methicilin-resistant S. aureus and VRE may make control of vancomycin-resistant S. aureus impossible.Methods: In the medical microbiology laboratory of Institute Public Health Kranj we perform microbiology diagnosis for Jesenice General Hospital, where surveillance culturing for VRE started in May 2007. Until 15th June, 364 surveillance samples for VRE were taken from 92 patients. We also analysed the results of enterococci that were isolated in our laboratory during routine work in the period from 2004 to 2006.Results: In the three-year period we isolated 1593 strains of enterococci and among them 7 strains were VRE. In the Jesenice General Hospital, the first strain of vancomycin-resistant Enterococcus faecium was isolated in May 2007 in a patient, treated in internal intensive care unit. Nine strains of VRE with the same resistance type in nine patients followed the first case. The first four patients with VRE were moved from the same hospital. Among next six patients the common risk factor was contact with VRE positive patient.Conclusions: Control of VRE strains claims for intensive action. Active surveillance of colonised and infected patients, contact precautions with barrier isolation, intensive hand hygiene measures, aggressive environmental decontamination and prudent use of antimicrobials are needed.

Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

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Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

2015-12-01

Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Is the mazEF toxin-antitoxin system responsible for vancomycin resistance in clinical isolates of Enterococcus faecalis?

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Sadeghifard, Nourkhoda; Soheili, Sara; Sekawi, Zamberi; Ghafourian, Sobhan

2014-01-01

The current study was conducted to investigate the relationship between vancomycin-resistant Enterococcus faecalis (VRE) and the presence of mazEF toxin-antitoxin (TA) system, which may be useful as target for novel antimicrobial therapy concepts. The susceptibility of E. faecalis was determined by MIC, and the presence of the mazEF TA system was evaluated by PCR. Among 200 E. faecalis isolates 39.5% showed resistance to vancomycin (VRE), while 60.5% were susceptible strains (VSE). The mazEF TA system was positive in all VRE isolates (100%), but less prevalent (38/121, 31.4%) among the 121 VSE strains. In conclusion, our study demonstrated a positive relationship between the presence of vancomycin resistance and mazEF TA system. This observation may introduce therapeutic options against a novel antimicrobial target in enterococci.

Antibiotic Resistance Patterns of Enterococci and Occurrence of Vancomycin-Resistant Enterococci in Raw Minced Beef and Pork in Germany

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Klein, Günter; Pack, Alexander; Reuter, Gerhard

1998-01-01

The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings. PMID:9572958

Assessing outcomes of adult oncology patients treated with linezolid versus daptomycin for bacteremia due to vancomycin-resistant Enterococcus.

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Patel, Khilna; Kabir, Rubiya; Ahmad, Samrah; Allen, Steven L

2016-04-01

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. 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. 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. 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. © The Author(s) 2014.

[Vancomycin-resistant enterococci - the nature of resistance and risk of transmission from animals to humans].

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Hermanovská, Lýdia; Bardoň, Jan; Čermák, Pavel

2016-06-01

Enterococci are part of the normal intestinal flora of humans and animals. Under certain circumstances, they are capable of extraintestinal conversion to opportunistic pathogens. They cause endogenous as well as exogenous community and nosocomial infections. The gastrointestinal tract of mammals provides them with favorable conditions for acquisition and spread of resistance genes, for example to vancomycin (van), from other symbiotic bacteria. Thus, vancomycin-resistant enterococci (VRE) become potential reservoirs and vectors of the van genes. Their occurrence in the population of the Czech Republic was first reported by Kolář et al. in 1997. Some variants of the vanA gene cluster carried on Tn1546 which encode resistance to vancomycin are identical in humans and in animals. It means that animals, especially cattle, poultry and pigs, could be an important reservoir of VRE for humans. Kolář and Bardoň detected VRE in animals in the Czech Republic for the first time in 2000. In Europe, the glycopeptide antibiotic avoparcin, used as a growth stimulator, is responsible for selection of VRE strains in animals. Strains of Enterococcus faecium from animals may offer genes of antimicrobial resistance to other enterococci or they can be directly dangerous to human. This is demonstrated by finding isolates of E. faecalis from human patients and from pigs having very similar profiles of resistance and virulence genes. The goal of the paper was to point out the similarity between isolates of human and animal strains of enterococci resistant to vancomycin, and the possibility of their bilateral transfer between humans and animals.

Recovery of vancomycin-resistant gram-positive cocci from children.

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Green, M; Wadowsky, R M; Barbadora, K

1990-03-01

A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium. Plates were incubated at 35 degrees C with 5% carbon dioxide and examined at 24, 48, and 72 h. Susceptibilities were determined by broth microdilution. A total of 14 isolates from 11 of 48 (22%) children were recovered. The density of growth ranged from a single colony to 2+. The VRGPC were identified as Leuconostoc lactis (n = 2), Lactobacillus confusus (n = 4), Enterococcus species (n = 5), and Lactococcus lactis (n = 3). One strain of Lactobacillus confusus was recovered from both the stool and the blood of one of these patients. The MICs of vancomycin were 4 micrograms/ml for one of the isolates, 8 micrograms/ml for four of the isolates, and more than 16 micrograms/ml for the remaining eight isolates. All isolates were susceptible to both penicillin and ampicillin. Only 1 of the 11 children had received prior treatment with vancomycin. We conclude that low concentrations of VRGPC may be common in the gastrointestinal tracts of children.

Cell Wall Remodeling by a Synthetic Analog Reveals Metabolic Adaptation in Vancomycin Resistant Enterococci.

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Pidgeon, Sean E; Pires, Marcos M

2017-07-21

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.

Structural and Functional Adaptation of Vancomycin Resistance VanT Serine Racemases.

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Meziane-Cherif, Djalal; Stogios, Peter J; Evdokimova, Elena; Egorova, Olga; Savchenko, Alexei; Courvalin, Patrice

2015-08-11

Vancomycin resistance in Gram-positive bacteria results from the replacement of the D-alanyl-D-alanine target of peptidoglycan precursors with D-alanyl-D-lactate or D-alanyl-D-serine (D-Ala-D-Ser), to which vancomycin has low binding affinity. VanT is one of the proteins required for the production of D-Ala-D-Ser-terminating precursors by converting L-Ser to D-Ser. VanT is composed of two domains, an N-terminal membrane-bound domain, likely involved in L-Ser uptake, and a C-terminal cytoplasmic catalytic domain which is related to bacterial alanine racemases. To gain insight into the molecular function of VanT, the crystal structure of the catalytic domain of VanTG from VanG-type resistant Enterococcus faecalis BM4518 was determined. The structure showed significant similarity to type III pyridoxal 5'-phosphate (PLP)-dependent alanine racemases, which are essential for peptidoglycan synthesis. Comparative structural analysis between VanTG and alanine racemases as well as site-directed mutagenesis identified three specific active site positions centered around Asn696 which are responsible for the L-amino acid specificity. This analysis also suggested that VanT racemases evolved from regular alanine racemases by acquiring additional selectivity toward serine while preserving that for alanine. The 4-fold-lower relative catalytic efficiency of VanTG against L-Ser versus L-Ala implied that this enzyme relies on its membrane-bound domain for L-Ser transport to increase the overall rate of d-Ser production. These findings illustrate how vancomycin pressure selected for molecular adaptation of a housekeeping enzyme to a bifunctional enzyme to allow for peptidoglycan remodeling, a strategy increasingly observed in antibiotic-resistant bacteria. Vancomycin is one of the drugs of last resort against Gram-positive antibiotic-resistant pathogens. However, bacteria have evolved a sophisticated mechanism which remodels the drug target, the D-alanine ending precursors in cell wall

Vancomycin-resistant Staphylococcus aureus (VRSA) in hepatic cirrhosis patient: a case report

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Ramazoni, M.; Siregar, M. L.; Jamil, K. F.

2018-03-01

The irrational use of vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) infections result in the emergence of vancomycin-resistant Staphylococcus aureus (VRSA) pathogen, which can pose a threat to the world healthcare. A 32-year-old male with hepatic cirrhosis patient admitted with recurrent gastrointestinal bleeding with a wound in his left leg since 6 months ago; the result microbiological culture showed a VRSA with minimum inhibitory concentration (MIC) vancomycin ≥32μg/mL The patient was treated with trimethoprim/sulfamethoxazole combination according to cultural sensitivity. The second microbiological culture showed thesame result. VRSA is a rare and difficult condition to handle. The success of therapy for this VRSA case warn us how important to cut the S. aureus distribution chain with a high level of resistance.

Recovery of vancomycin-resistant gram-positive cocci from children.

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Green, M; Wadowsky, R M; Barbadora, K

1990-01-01

A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium....

Minimum inhibitory concentration of vancomycin to methicillin resistant Staphylococcus aureus isolated from different clinical samples at a tertiary care hospital in Nepal

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Arjun Ojha Kshetry

2016-07-01

Full Text Available Abstract Background Methicillin resistant Staphylococcus aureus (MRSA has evolved as a serious threat to public health. It has capability to cause infections not only in health care settings but also in community. Due to the multidrug resistance shown by MRSA, there are limited treatment options for the infections caused by this superbug. Vancomycin is used as the drug of choice for the treatment of infections caused by MRSA. Different studies from all around the world have documented the emergence of strains of S. aureus those are intermediate sensitive or resistant to vancomycin. And recently, there have been reports of reduced susceptibility of MRSA to vancomycin, from Nepal also. So the main purpose of this study was to determine the minimum inhibitory concentration (MIC of vancomycin to methicillin resistant S. aureus isolated from different clinical specimens. Methods Total 125 strains of S. aureus isolated from different clinical samples at KIST Medical College and Teaching Hospital, Lalitpur, Nepal from Nov 2012 to June 2013, were subjected to MRSA detection by cefoxitin disc diffusion method. The minimum inhibitory concentrations of vancomycin to confirmed MRSA strains were determined by agar dilution method. Yellow colored colonies in mannitol salt agar, which were gram positive cocci, catalase positive and coagulase positive were confirmed to be S. aureus. Results Among, total 125 S. aureus strains isolated; 47(37.6% were MRSA. Minimum inhibitory concentrations of vancomycin to the strains of MRSA ranged from 0.125 μg/ml to 1 μg/ml. Conclusion From our findings we concluded that the rate of isolation of MRSA among all the strains of S. aureus isolated from clinical samples was very high. However, none of the MRSA strains were found to be vancomycin intermediate-sensitive or vancomycin-resistant.

Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycin

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Rathe, Mathias; Kristensen, Lise; Ellermann-Eriksen, Svend

2010-01-01

Vancomycin-resistant enterococci (VRE) have emerged to become a significant nosocomial pathogen. However, detection may be challenging and treatment possibilities are limited. Reports of resistance to linezolide, daptomycin and tigecycline underline the need for reliable susceptibility testing wi...

Iterative Chemical Engineering of Vancomycin Leads to Novel Vancomycin Analogs With a High in Vitro Therapeutic Index

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Nigam M. Mishra

2018-06-01

Full Text Available Vancomycin is a glycopeptide antibiotic that inhibits transpeptidation during cell wall synthesis by binding to the D-Ala-D-Ala termini of lipid II. For long, it has been used as a last resort antibiotic. However, since the emergence of the first vancomycin-resistant enterococci in 1987, vancomycin resistance has become widespread, especially in hospitals. We have synthesized and evaluated 110 vancomycin analogs modified at the C-terminal carboxyl group of the heptapeptide moiety with R2NHR1NH2 substituents. Through iterative optimizations of the substituents, we identified vancomycin analogs that fully restore (or even exceed the original inhibitory activity against vancomycin-resistant enterococci (VRE, vancomycin-intermediate (VISA and vancomycin-resistant Staphylococcus aureus (VRSA strains. The best analogs have improved growth inhibitory activity and in vitro therapeutic indices against a broad set of VRE and methicillin-resistant S. aureus (MRSA isolates. They also exceed the activity of vancomycin against Clostridium difficile ribotypes. Vanc-39 and Vanc-42 have a low probability to provoke antibiotic resistance, and overcome different vancomycin resistance mechanisms (VanA, VanB, and VanC1.

Determination of antimicrobial resistance to extended-spectrum cephalosporin, quinolones, and vancomycin in selected human enteric pathogens from Prince Edward Island, Canada.

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Awosile, Babafela; German, Gregory; Rodriguez-Lecompte, Juan Carlos; Saab, Matthew E; Heider, Luke C; McClure, J Trenton

2018-04-05

The aim of this study was to determine the frequency of fecal carriage of vancomycin-resistant Enterococcus spp. and Escherichia coli with reduced susceptibilities to extended-spectrum cephalosporins (ESCs) and quinolones in humans on Prince Edward Island, Canada. Convenience fecal samples from individuals on Prince Edward Island were screened phenotypically using selective culture and genotypically using multiplex polymerase chain reactions to detect E. coli and Enterococcus spp. resistant to critically important antimicrobials. Twenty-six (5.3%) of 489 individuals had E. coli with reduced susceptibility to ESCs. Twenty-five (96.2%) of the 26 isolates harbored bla TEM , 18 (69.2%) harbored bla CMY-2 , 16 (61.5%) harbored bla CTX-M groups, 2 (7.7%) harbored bla SHV genes. None of the ESC-resistant E. coli was positive for carbapenem resistance. Twenty-one (8.3%) of 253 individuals had E. coli isolates with reduced quinolone susceptibility. All 21 isolates were positive for at least 1 qnr gene, with 3 (14.3%) isolates positive for qnrB, 5 (23.8%) positive for qnrS, and 13 (61.9%) positive for both qnrB and qnrS genes. All the enterococci isolates were vancomycin-susceptible. Higher susceptibility to the critically important antimicrobials was found in this study. This study can serve as a baseline for future antimicrobial resistance surveillance within this region.

Characterisation of the selective binding of antibiotics vancomycin and teicoplanin by the VanS receptor regulating type A vancomycin resistance in the enterococci.

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Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R

2017-08-01

A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.

Prevalence study of enterococus and staphylococci resistance to vancomycin isolated from urinary tract infections

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Mohammad Kazem Sharifi Yazdi

2013-07-01

Full Text Available Background: The role of gram-positive cocci especially Staphylococci species in causing urinary tract infection are well known. Among the Staphylococci species Methicillin Resistance Staphylococcus aureus (MRSA is the most important. The rate of MRSA is increasing worldwide. This is alarming because the danger of these organism in public health. Therefore the aim of this study was to determine the sensitivity of gram-positive cocci, as well as MRSA to vancomycin and other antibiotics.Methods: This was a descriptive study, and were carried out on 300 patients with urinary tract infections (UTI caused by gram-positive cocci, referred to Imam Khomeini hospital during eight months. Prior to the antibiotic sensitivity testing all the isolates were identified according to the standard conventional biochemical procedure, and then the antibiotic susceptibility test were carried out according to Bauer-Kirby method. Results: Among the gram positive cocci causing UTI, the most abundant were Staphylococcus saprophyticus (37.7%, followed by Staphylococcus epidermidis (22.3% and Staphylococcus aureus (18% respectivley. The sex distribution of patients were 163 female (54.3% and 137 male (45.7% respectively, and the prevalence rate of urinary tract infections in female was (8.6% higher than male. The rate of sensitivity of isolated Staphylococci were as followed, sensitive to vancomycine (100%, Ciprofloxacin (89.2%, rifampin (87.6%, and amikacin (71.8% respectivley, but were resistant to penicillin and amoxicillin (100%. The antibiotic sensitivity rate of isolated  Streptococci was to vancomycine (85.1%, ciprofloxacin (50.7% and penicillin (79.1% respectively.Conclusion: Vancomycin is still a suitable antibiotic for the treatment of Staphyloco-ccus infections. Although 6% rate of enterococci resistance to vancomycin is alarming, and use of this antibiotic in the treatment of other gram-positive bacteria should be done with precaution.

Identification of VanN-type vancomycin resistance in an Enterococcus faecium isolate from chicken meat in Japan.

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Nomura, Takahiro; Tanimoto, Koichi; Shibayama, Keigo; Arakawa, Yoshichika; Fujimoto, Shuhei; Ike, Yasuyoshi; Tomita, Haruyoshi

2012-12-01

Five VanN-type vancomycin-resistant Enterococcus faecium strains were isolated from a sample of domestic chicken meat in Japan. All isolates showed low-level resistance to vancomycin (MIC, 12 mg/liter) and had the same pulsed-field gel electrophoresis profile. The vancomycin resistance was encoded on a large plasmid (160 kbp) and was expressed constitutively. The VanN-type resistance operon was identical to the first resistance operon to be reported, with the exception of a 1-bp deletion in vanT(N) and a 1-bp substitution in vanS(N).

Meningitis associated with Vancomycin resistant Enterococcus casseliflavus: First report

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Nilay Sefa Uçar

2011-12-01

Full Text Available Enterococci are present in the gastrointestinal system as normal floral components. In the past two decades membersof the genus Enterococcus have emerged as important nosocomial pathogens worldwide. Enterococci may cause arange of different disorders such as urinary tract, intraabdominal, and wound infections, as well as endocarditis, meningitisand bacteraemia. Nosocomial enterococcal meningitis is most commonly observed following ventriculoperitonealshunt operations. Vancomycin resistant enterococcus (VRE represents 30% of all enterococci infections.This report presents a vancomycin-resistant Enterococcus casseliflavus meningitis case in a 66-year-old patient withventriculoperitoneal shunt, which has not been reported in the literature before. Successful outcomes were obtainedwith daptomycin plus linezolid combined treatment in VRE meningitis. Treatment recommendations in VRE meningitisare also discussed in this article. J Microbiol Infect Dis 2011;1 (3:138-140

Wounds, Functional Disability, and Indwelling Devices Are Associated With Cocolonization by Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci in Southeast Michigan

OpenAIRE

Flannery, Erika L.; Wang, Linda; Zöllner, Sebastian; Foxman, Betsy; Mobley, Harry L. T.; Mody, Lona

2011-01-01

Cocolonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) is a precursor to vancomycin-resistant S. aureus emergence. MRSA/VRE cocolonization incidence is higher among skilled nursing facility residents with functional disability and indwelling devices and occurs more frequently in wounds than other anatomical sites.

Determining vancomycin clearance in an overweight and obese population.

Science.gov (United States)

Leong, Julie V B; Boro, Maureen S; Winter, Michaele

2011-04-01

Two methods of calculating vancomycin clearance were compared to determine the best body weight measure to use when dosing vancomycin for overweight and obese patients. Hospitalized veterans weighing more than 120% of their ideal body weight (IBW) with serum vancomycin concentrations (SVCs) drawn between January 1, 2003, and June 30, 2005, were eligible for study inclusion. Exclusion criteria included weight of more than 300% the IBW, unstable renal function, dialysis, uncertain vancomycin dosing or sampling times, and distribution-phase sampling. Data from January 1 through December 31, 2003 (phase 1) determined the best-fit weight for vancomycin clearance for the Leonard and Boro method. The bias and precision of the modified Leonard and Boro method using the best-fit weight for vancomycin clearance were then compared with those of the Rushing and Ambrose method for predicting SVCs from January 1, 2004, through June 30, 2005 (phase 2). Forty-eight patients were included in phase 1, with 67 SVCs for analysis. During phase 1, adjusted body weight (ABW), using the Leonard and Boro method, was superior in predicting vancomycin clearance and the resultant SVCs. A total of 96 patients were included in phase 2 of the study, with 160 SVCs for analysis. The modified Leonard and Boro method was significantly more precise than the Rushing and Ambrose method in predicting vancomycin clearance. Use of ABW proved to be superior compared with total body weight when estimating vancomycin clearance in overweight and obese patients. While there was no difference in bias between methods, the modified Leonard and Boro method was significantly more precise than the Rushing and Ambrose method in predicting SVCs when dosing vancomycin for obese patients.

Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA strain of clonal type USA300.

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Susana Gardete

2012-02-01

Full Text Available An isolate of the methicillin-resistant Staphylococcus aureus (MRSA clone USA300 with reduced susceptibility to vancomycin (SG-R (i.e, vancomycin-intermediate S. aureus, VISA and its susceptible "parental" strain (SG-S were recovered from a patient at the end and at the beginning of an unsuccessful vancomycin therapy. The VISA phenotype was unstable in vitro generating a susceptible revertant strain (SG-rev. The availability of these 3 isogenic strains allowed us to explore genetic correlates of antibiotic resistance as it emerged in vivo. Compared to the susceptible isolate, both the VISA and revertant strains carried the same point mutations in yycH, vraG, yvqF and lspA genes and a substantial deletion within an intergenic region. The revertant strain carried a single additional frameshift mutation in vraS which is part of two component regulatory system VraSR. VISA isolate SG-R showed complex alterations in phenotype: decreased susceptibility to other antibiotics, slow autolysis, abnormal cell division and increased thickness of cell wall. There was also altered expression of 239 genes including down-regulation of major virulence determinants. All phenotypic properties and gene expression profile returned to parental levels in the revertant strain. Introduction of wild type yvqF on a multicopy plasmid into the VISA strain caused loss of resistance along with loss of all the associated phenotypic changes. Introduction of the wild type vraSR into the revertant strain caused recovery of VISA type resistance. The yvqF/vraSR operon seems to function as an on/off switch: mutation in yvqF in strain SG-R turns on the vraSR system, which leads to increase in vancomycin resistance and down-regulation of virulence determinants. Mutation in vraS in the revertant strain turns off this regulatory system accompanied by loss of resistance and normal expression of virulence genes. Down-regulation of virulence genes may provide VISA strains with a "stealth

Detection of vancomycin resistances in enterococci within 3 1/2 hours

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Schröder, U. -Ch.; Beleites, C.; Assmann, C.; Glaser, U.; Hübner, U.; Pfister, W.; Fritzsche, W.; Popp, J.; Neugebauer, U.

2015-02-01

Vancomycin resistant enterococci (VRE) constitute a challenging problem in health care institutions worldwide. Novel methods to rapidly identify resistances are highly required to ensure an early start of tailored therapy and to prevent further spread of the bacteria. Here, a spectroscopy-based rapid test is presented that reveals resistances of enterococci towards vancomycin within 3.5 hours. Without any specific knowledge on the strain, VRE can be recognized with high accuracy in two different enterococci species. By means of dielectrophoresis, bacteria are directly captured from dilute suspensions, making sample preparation very easy. Raman spectroscopic analysis of the trapped bacteria over a time span of two hours in absence and presence of antibiotics reveals characteristic differences in the molecular response of sensitive as well as resistant Enterococcus faecalis and Enterococcus faecium. Furthermore, the spectroscopic fingerprints provide an indication on the mechanisms of induced resistance in VRE.

Antimicrobial growth promoter ban and resistance to macrolides and vancomycin in enterococci from pigs

DEFF Research Database (Denmark)

Boerlin, P.; Wissing, A.; Aarestrup, Frank Møller

2001-01-01

Ninety-six enterococcus isolates from fecal samples of pigs receiving tylosin as an antimicrobial growth promoter and 59 isolates obtained in the same farms 5 to 6 months after the ban of antimicrobial growth promoters in Switzerland were tested for susceptibility to nine antimicrobial agents....... A clear decrease in resistance to macrolides, lincosamides, and tetracycline was visible after the ban. Vancomycin-resistant Enterococcus faecium belonged to the same clonal lineage as vancomycin-resistant isolates previously isolated from Danish pigs....

Review on Usage of Vancomycin in Livestock and Humans: Maintaining Its Efficacy, Prevention of Resistance and Alternative Therapy

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Panditharathnalage Nishantha Kumara Wijesekara

2017-01-01

Full Text Available Vancomycin is one of the “last-line” classes of antibiotics used in the treatment of life-threatening infections caused by Gram-positive bacteria. Even though vancomycin was discovered in the 1950s, it was widely used after the 1980s for the treatment of infections caused by methicillin-resistant Staphylococci, as the prevalence of these strains were increased. However, it is currently evident that vancomycin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci have developed for various reasons, including the use of avaparcin—an analog of vancomycin—as a feed additive in livestock. Therefore, prophylactic and empiric use of antibiotics and their analogues need to be minimized. Herein we discuss the rational use of vancomycin in treating humans, horses, farm animals, and pet animals such as dogs, cats, and rabbits. In present day context, more attention should be paid to the prevention of the emergence of resistance to antibiotics in order to maintain their efficacy. In order to prevent emergence of resistance, proper guidance for the responsible use of antimicrobials is indispensable. Therefore, almost all stakeholders who use antibiotics should have an in-depth understanding of the antibiotic that they use. As such, it is imperative to be aware of the important aspects of vancomycin. In the present review, efforts have been made to discuss the pharmacokinetics and pharmacodynamics, indications, emergence of resistance, control of resistance, adverse effects, and alternative therapy for vancomycin.

Characterization of vancomycin-resistant and vancomycin-susceptible Enterococcus faecium isolates from humans, chickens and pigs by RiboPrinting and pulsed-field gel electrophoresis

DEFF Research Database (Denmark)

Hammerum, Anette Marie; Fussing, Vivian; Aarestrup, Frank Møller

2000-01-01

Forty-eight vancomycin-resistant and 35 vancomycin-sensitive Danish Enterococcus faecium isolates obtained from pigs, chickens and humans, as well as the human vanA reference isolate BM4147, were characterized by EcoRI RiboPrinting and Smal pulsed-field gel electrophoresis. RiboPrinting of the 84...

vanI: a novel d-Ala-d-Lac vancomycin resistance gene cluster found in Desulfitobacterium hafniense

NARCIS (Netherlands)

Kruse, T.; Levisson, M.; Vos, de W.M.; Smidt, H.

2014-01-01

The glycopeptide vancomycin was until recently considered a drug of last resort against Gram-positive bacteria. Increasing numbers of bacteria, however, are found to carry genes that confer resistance to this antibiotic. So far, 10 different vancomycin resistance clusters have been described. A

Molecular characterization of vancomycin-resistant Enterococcus faecium isolates from Bermuda.

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Patrick Eberechi Akpaka

Full Text Available Molecular characteristics of vancomycin resistant enterococci isolates from Bermuda Island is currently unknown. This study was conducted to investigate phenotypic and genotypic characteristics of VRE isolates from Bermuda Island using the chromogenic agar, E-tests, polymerase chain reaction (PCR, pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. Eighteen E. faecium isolates were completely analyzed and were all resistant to vancomycin, susceptible to linezolid and quinupristin/dalfopristin, positive for vanA and esp genes. The MLST analysis confirmed most isolates were of the sequence types linked to clonal complex 17 (CC17 that is widely associated with outbreaks in hospitals. Infection control measures, antibiotic stewardship, and surveillance activities will continue to be a priority in hospital on the Island.

[Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis].

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León, Jorge; Aponte, Juan José; Rojas, Rosario; Cuadra, D'Lourdes; Ayala, Nathaly; Tomás, Gloria; Guerrero, Marco

2011-06-01

To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound. Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85% for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99% similarity with the marine species Streptomyces erythrogriseus. Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drug-resistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.

Vancomycin-Resistant Enterococci and Bacterial Community Structure following a Sewage Spill into an Aquatic Environment

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Young, Suzanne; Nayak, Bina; Sun, Shan; Badgley, Brian D.; Rohr, Jason R.

2016-01-01

ABSTRACT Sewage spills can release antibiotic-resistant bacteria into surface waters, contributing to environmental reservoirs and potentially impacting human health. Vancomycin-resistant enterococci (VRE) are nosocomial pathogens that have been detected in environmental habitats, including soil, water, and beach sands, as well as wildlife feces. However, VRE harboring vanA genes that confer high-level resistance have infrequently been found outside clinical settings in the United States. This study found culturable Enterococcus faecium harboring the vanA gene in water and sediment for up to 3 days after a sewage spill, and the quantitative PCR (qPCR) signal for vanA persisted for an additional week. Culturable levels of enterococci in water exceeded recreational water guidelines for 2 weeks following the spill, declining about five orders of magnitude in sediments and two orders of magnitude in the water column over 6 weeks. Analysis of bacterial taxa via 16S rRNA gene sequencing showed changes in community structure through time following the sewage spill in sediment and water. The spread of opportunistic pathogens harboring high-level vancomycin resistance genes beyond hospitals and into the broader community and associated habitats is a potential threat to public health, requiring further studies that examine the persistence, occurrence, and survival of VRE in different environmental matrices. IMPORTANCE Vancomycin-resistant enterococci (VRE) are harmful bacteria that are resistant to the powerful antibiotic vancomycin, which is used as a last resort against many infections. This study followed the release of VRE in a major sewage spill and their persistence over time. Such events can act as a means of spreading vancomycin-resistant bacteria in the environment, which can eventually impact human health. PMID:27422829

Clinical Outcome with Oral Linezolid and Rifampin Following Recurrent Methicillin-Resistant Staphylococcus aureus Bacteremia Despite Prolonged Vancomycin Treatment

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Jon-David Schwalm

2004-01-01

Full Text Available Drug-resistant Gram-positive bacteria, especially Staphylococcus aureus, are emerging as the predominant organisms involved in both nosocomial and community-acquired infections. Since the 1980s, vancomycin has been the first-line antibiotic used to treat methicillin-resistant S aureus. However, allergy and intolerance to vancomycin, the increasing number of vancomycin clinical failures and the existence of vancomycin intermediate-susceptible isolates of S aureus suggest that new antibiotics are needed. This paper reports the only known case of a successful clinical outcome with long term oral linezolid and rifampin therapy in the management of recurrent and persistent methicillin-resistant S aureus bacteremia with metastatic infections despite prolonged vancomycin use. More than two years since the initiation of linezolid and rifampin, the study patient has been clinically well with no evidence of adverse drug reactions including cytopenia and hepatic toxicities. Physicians must be aware of the novel developments in antibiotic therapy to treat drug-resistant bacterial infections.

Occurrence of vancomycin-resistant Staphylococcus aureus in the oral cavity of patients with dental caries.

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Vellappally, Sajith; Divakar, Darshan Devang; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Alqahtani, Amer; Dalati, M H N; Anil, Sukumaran; Khan, Aftab Ahmed; Harikrishna Varma, P R

2017-09-01

Oral streptococci are the major group of microbes isolated from oral microflora. They represent frequent pathogens of infective endocarditis (IE), and it is assumed that in most of the cases oral streptococci are acquired via mucosa layer of oral cavity. Staphylococcus aureus is also frequently isolated from IE as it accounts for 20%-30% of all cases. Vancomycin has been the most reliable therapeutic agent against infections caused by methicillin-resistant S. aureus (MRSA). The main objective of this study was to examine the occurrence of S. aureus species in dental caries specimens. Antimicrobial susceptibility testing of S. aureus to four antibiotics namely vancomycin, linezolid, teicoplanin, and daptomycin was performed. Detection of vancomycin resistance was conducted using polymerase chain reaction. Among the tested 150 strains, 98 were MRSA and of that 54 were vancomycin sensitive and 27 were resistant. All 98 MRSA strains were positive for mecA and 36 yielded pvl, whereas 13 carried vanA and only 2 were positive for vanB. Majority of the isolates showed sensitivity toward daptomycin and linezolid. Strains of S. aureus exhibiting decreased susceptibility to different antibiotics like vancomycin, daptomycin, and linezolid severely compromise the therapeutic alternatives and require a considerable amount of time, public awareness, and integrative health-care strategies to prevent the emergence of resistance to these compounds.

Increasing Incidence of Linezolid-Intermediate or -Resistant, Vancomycin-Resistant Enterococcus faecium Strains Parallels Increasing Linezolid Consumption▿

OpenAIRE

Scheetz, Marc H.; Knechtel, Stephanie A.; Malczynski, Michael; Postelnick, Michael J.; Qi, Chao

2008-01-01

Clinical enterococcal resistance to linezolid is defined by the presence of the G2576T mutation. We evaluated the incidence of genetically proven linezolid resistance among vancomycin-resistant Enterococcus faecium strains and linezolid consumption for a possible association. A relationship was found (r2 = 0.73, P = 0.03) and predicts increasing resistance with current trends of linezolid use.

Success of linezolid therapy for postneurosurgical ventriculitis due to vancomycin-resistant Enterococcus faecium: case report and literature review

Institute of Scientific and Technical Information of China (English)

JiaJi Qiu; Jie Tang; DeLing Li

2016-01-01

Background:Vancomycin-resistant Enterococcus faecium ventriculitis is one of the most severe events in postneurosurgical intracranial infections.There are no guidelines recommending an appropriate treatment before.Case presentation:This case presents a successful linezolid treatment for post-neurosurgical vancomycin-resistant Enterococcus faecium ventriculitis of a 24-year-old man in the department of neurosurgery,Beijing Tiantan Hospital.Conclusions:Linezolid should be considered as one of the important methods for the treatment of postneurosurgical intracranial infections caused by vancomycin-resistant Enterococcus.

Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia.

Science.gov (United States)

Soriano, Alex; Marco, Francesc; Martínez, José A; Pisos, Elena; Almela, Manel; Dimova, Veselka P; Alamo, Dolores; Ortega, Mar; Lopez, Josefina; Mensa, Josep

2008-01-15

Vancomycin treatment failure in methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is not uncommon, even when MRSA is susceptible to vancomycin. The aim of our study was to evaluate whether vancomycin minimum inhibitory concentration has any influence on the mortality associated with MRSA bacteremia. A total of 414 episodes of MRSA bacteremia were prospectively followed-up from 1991 through 2005. MIC of vancomycin for the first isolate was determined by E-test. Clinical variables recorded were age, comorbidity, prior administration of vancomycin, use of corticosteroids, prognosis of underlying disease, source of bacteremia, the need for mechanical ventilation, shock, and mortality. A "treatment group" variable was created and defined as follows: (1) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1 microg/mL (38 episodes), (2) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 1.5 microg/mL (90 episodes), (3) receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (40 episodes), and (4) receipt of inappropriate empirical therapy (246 episodes). Univariate and multivariate analyses were performed. Episodes caused by strains with a vancomycin MIC of 2 microg/mL were independently associated with a lower risk of shock (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.15-0.75). Multivariate analysis selected receipt of empirical vancomycin and an isolate with a vancomycin MIC of 2 microg/mL (OR, 6.39; 95% CI, 1.68-24.3), receipt of inappropriate empirical therapy (OR, 3.62; 95% CI, 1.20-10.9), increasing age (OR, 1.02; 95% CI, 1.00-1.04), use of corticosteroids (OR, 1.85; 95% CI, 1.04-3.29), an ultimately (OR, 10.2; 95% CI, 2.85-36.8) or rapidly (OR, 1.81; 95% CI, 1.06-3.10) fatal underlying disease, high-risk (OR, 3.60; 95% CI, 1.89-6.88) and intermediate-risk (OR, 2.18; 95% CI, 1.17-4.04) sources of bacteremia, and shock (OR, 7.38; 95% CI, 4.11-13.3) as the best predictors of

Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin-resistant Enterococci.

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McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J

2016-02-01

Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.

Contamination of the Clinical Microbiology Laboratory with Vancomycin-Resistant Enterococci and Multidrug- Resistant Enterobacteriaceae: Implications for Hospital and Laboratory Workers

Science.gov (United States)

Collins, Susan M.; Hacek, Donna M.; Degen, Lisa A.; Wright, Marc O.; Noskin, Gary A.; Peterson, Lance R.

2001-01-01

We surveyed environmental surfaces in our clinical microbiology laboratory to determine the prevalence of vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) during a routine working day. From a total of 193 surfaces, VRE were present on 20 (10%) and MDRE were present on 4 (2%) of the surfaces tested. In a subsequent survey after routine cleaning, all of the 24 prior positive surfaces were found to be negative. Thus, those in the laboratory should recognize that many surfaces may be contaminated by resistant organisms during routine processing of patient specimens. PMID:11574615

Presence of virulence factors in Enterococcus faecalis and Enterococcus faecium susceptible and resistant to vancomycin

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Carolina Baldisserotto Comerlato

2013-08-01

Full Text Available Despite the increasing importance of Enterococcus as opportunistic pathogens, their virulence factors are still poorly understood. This study determines the frequency of virulence factors in clinical and commensal Enterococcus isolates from inpatients in Porto Alegre, Brazil. Fifty Enterococcus isolates were analysed and the presence of the gelE, asa1 and esp genes was determined. Gelatinase activity and biofilm formation were also tested. The clonal relationships among the isolates were evaluated using pulsed-field gel electrophoresis. The asa1, gelE and esp genes were identified in 38%, 60% and 76% of all isolates, respectively. The first two genes were more prevalent in Enterococcus faecalis than in Enterococcus faecium, as was biofilm formation, which was associated with gelE and asa1 genes, but not with the esp gene. The presence of gelE and the activity of gelatinase were not fully concordant. No relationship was observed among any virulence factors and specific subclones of E. faecalis or E. faecium resistant to vancomycin. In conclusion, E. faecalis and E. faecium isolates showed significantly different patterns of virulence determinants. Neither the source of isolation nor the clonal relationship or vancomycin resistance influenced their distribution.

Infection dynamics of vancomycin and inducible clindamycin resistant Enterococcus faecalis in an Indian teaching hospital

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Debasmita Dubey

2015-06-01

Full Text Available Objective: To do surveillance for vancomycin and inducible clindamycin resistance of Enterococcus faecalis (E. faecalis, a Gram-positive bacterium in a teaching hospital. Methods: E. faecalis strains isolated from clinical samples were screened for vancomycin and inducible clindamycin resistance, i.e., D-test positivity, using vancomycin screen agar and blood agar plates, respectively. For the D-test screening, erythromycin resistant (Er-r and clindamycin sensitive (Cd-s strain were used. Results: Of 265 isolated E. faecalis strains, 159 (60% were vancomycin resistant Enterococcus (VRE and 106 were vancomycin sensitive Enterococcus (VSE. Of 265 strains, 42 were constitutively resistant to clindamycin and erythromycin and of 148 Er-r and Cd-s strains, 87 (32.83% had D-test positivity, while the rest 61 strains were D-test negatives. D-test results examined with 6 hospital factors as bivalents, only 2 factors, the VSE/VRE and the presence/absence of prior antibiotic use > 90 days bivalent were statistically significant. A VRE strain with D-test positivity would be picked up 0.570 2 times more frequently than a strain with VSE and D-test positivity. Also, patients with prior antibiotic use > 90 days had 3.737 5 times more chance of picking up D-test positive strains than patients without any prior antibiotic use. Resistance pattern of E. faecalis strains to individual 14 antibiotics were recorded; the maximum values of resistance were against ampicillin 10 μg/disc and linezolid 30 μg/disc. Student’s t-test for hospital acquired and community acquired data revealed that drug resistant strains were equally prevalent in both sources. Conclusions: Prevalence of 60% VRE in both hospital and adjoining community creates consternation. In total 87 (32.83% strains had D-test positivity; patients who had used antibiotics within the last 90 days have got an ample chance of picking of D-test positive E. faecalis. D-test protocol should be followed with

Presence of the resistance genes vanC1 and pbp5 in phenotypically vancomycin and ampicillin susceptible Enterococcus faecalis.

Science.gov (United States)

Schwaiger, Karin; Bauer, Johann; Hörmansdorfer, Stefan; Mölle, Gabriele; Preikschat, Petra; Kämpf, Peter; Bauer-Unkauf, Ilse; Bischoff, Meike; Hölzel, Christina

2012-08-01

Ampicillin and vancomycin are important antibiotics for the therapy of Enterococcus faecalis infections. The ampicillin resistance gene pbp5 is intrinsic in Enterococcus faecium. The vanC1 gene confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Both genes are chromosomally located. Resistance to ampicillin and vancomycin was determined in 484 E. faecalis of human and porcine origin by microdilution. Since E. faecalis are highly skilled to acquire resistance genes, all strains were investigated for the presence of pbp5 (and, in positive strains, for the penicillin-binding protein synthesis repressor gene psr) and vanC1 (and, in positive strains, for vanXYc and vanT) by using polymerase chain reaction (PCR). One porcine and one human isolate were phenotypically resistant to ampicillin; no strain was vancomycin resistant. Four E. faecalis (3/1 of porcine/human origin) carried pbp5 (MIC=1 mg/L), and four porcine strains were vanC1 positive (minimum inhibitory concentration [MIC]=1 mg/L). Real-time reverse transcriptase (RT)-PCR revealed that the genes were not expressed. The psr gene was absent in the four pbp5-positive strains; the vanXYc gene was absent in the four vanC1-positive strains. However, vanT of the vanC gene cluster was detected in two vanC1-positive strains. To our knowledge, this is the first report on the presence of pbp5, identical with the "E. faecium pbp5 gene," and of vanC1/vanT in E. faecalis. Even if resistance is not expressed in these strains, this study shows that E. faecalis have a strong ability to acquire resistance genes-and potentially to spread them to other bacteria. Therefore, close monitoring of this species should be continued.

Novel Inhibitors of Staphyloxanthin Virulence Factor in Comparison with Linezolid and Vancomycin versus Methicillin-Resistant, Linezolid-Resistant, and Vancomycin-Intermediate Staphylococcus aureus Infections in Vivo.

Science.gov (United States)

Ni, Shuaishuai; Wei, Hanwen; Li, Baoli; Chen, Feifei; Liu, Yifu; Chen, Wenhua; Xu, Yixiang; Qiu, Xiaoxia; Li, Xiaokang; Lu, Yanli; Liu, Wenwen; Hu, Linhao; Lin, Dazheng; Wang, Manjiong; Zheng, Xinyu; Mao, Fei; Zhu, Jin; Lan, Lefu; Li, Jian

2017-10-12

Our previous work ( Wang et al. J. Med. Chem. 2016 , 59 , 4831 - 4848 ) revealed that effective benzocycloalkane-derived staphyloxanthin inhibitors against methicillin-resistant Staphylococcus aureus (S. aureus) infections were accompanied by poor water solubility and high hERG inhibition and dosages (preadministration). In this study, 92 chroman and coumaran derivatives as novel inhibitors have been addressed for overcoming deficiencies above. Derivatives 69 and 105 displayed excellent pigment inhibitory activities and low hERG inhibition, along with improvement of solubility by salt type selection. The broad and significantly potent antibacterial spectra of 69 and 105 were displayed first with normal administration in the livers and hearts in mice against pigmented S. aureus Newman, Mu50 (vancomycin-intermediate S. aureus), and NRS271 (linezolid-resistant S. aureus), compared with linezolid and vancomycin. In summary, both 69 and 105 have the potential to be developed as good antibacterial candidates targeting virulence factors.

Evaluation of vancomycin MIC creep in methicillin-resistant Staphylococcus aureus infections-a systematic review and meta-analysis.

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Diaz, R; Afreixo, V; Ramalheira, E; Rodrigues, C; Gago, B

2018-02-01

Vancomycin is currently the primary option treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing number of MRSA isolates with high MICs, within the susceptible range (vancomycin MIC creep), are being reported worldwide. Resorting to a meta-analysis approach, this study aims to assess the evidence of vancomycin MIC creep. We searched for studies in the PubMed database. The inclusion criteria for study eligibility included the possibility of retrieving the reported data values of vancomycin MIC and information concerning the applied MIC methodology. The mean values of vancomycin MICs, of all 29 234 S. aureus isolates reported in the 55 studies included in the meta-analysis, were 1.23 mg/L (95% CI 1.13-1.33) and 1.20 mg/L (95% CI 1.13-1.28) determined by Etest and broth microdilution method, respectively. No significant differences were observed between these two methodologies. We found negative correlation between pooled mean/pooled proportion and time strata. We have found no evidence of the MIC creep phenomenon. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

High-Level Vancomycin-Resistant Staphylococcus aureus (VRSA in Iran: A Systematic Review

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Emran Askari

2015-10-01

Full Text Available Background: Staphylococcus aureus is a major human pathogen world- wide. Vancomycin has been used for decades to treat multidrug resistant S. aureus. Ten years has passed since the first report of vancomycin re- sistant S. aureus (VRSA. The objective of this systematic review was to determine  the total number of VRSA isolates that have been reported from Iran.Methods:  Search terms reflected “Iran”, “vancomycin” and “S. aureus” were  searched  in the ISI web  of knowledge,  PubMed,  SciVerse,  and Google scholar. Also two Persian scientific databases and 13 recent na- tional congresses  were investigated.  Articles / abstracts working on S. aureus in Iran, evaluating vancomycin MIC and / or PCR of vanA/B were included in this systematic review.Results: Out of the 3484 records found in mentioned resources, 13 re-lated studies were included in the final analysis. The result showed that at least 24 VRSA isolates which have been reported from Iran up to Sep- tember 2012.Conclusion: It seems that many Iranian researchers did not follow a spe- cific guideline for reporting and confirming VRSA. Establishing an Ira- nian reference center where studies on VRSA can be registered, evaluat- ed and confirmed is strongly recommended.

Ceftaroline-Resistant, Daptomycin-Tolerant, and Heterogeneous Vancomycin-Intermediate Methicillin-Resistant Staphylococcus aureus Causing Infective Endocarditis.

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Nigo, Masayuki; Diaz, Lorena; Carvajal, Lina P; Tran, Truc T; Rios, Rafael; Panesso, Diana; Garavito, Juan D; Miller, William R; Wanger, Audrey; Weinstock, George; Munita, Jose M; Arias, Cesar A; Chambers, Henry F

2017-03-01

We report a case of infective endocarditis (IE) caused by ceftaroline-resistant, daptomycin-tolerant, and heterogeneous vancomycin-intermediate methicillin-resistant S. aureus (MRSA). Resistance to ceftaroline emerged in the absence of drug exposure, and the E447K substitution in the active site of PBP2a previously associated with ceftaroline resistance was identified. Additionally, we present evidence of patient-to-patient transmission of the strain within the same unit. This case illustrates the difficulties in treating MRSA IE in the setting of a multidrug-resistant phenotype. Copyright © 2017 American Society for Microbiology.

An optimal method for generating stable vancomycin heteroresistance and intermediate susceptibility in methicillin-resistant Staphylococcus aureusblood isolates under in-vitro vancomycin pressure

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Riad Khatib

2012-12-01

Full Text Available Objectives: The relevance of vancomycin intermediately-susceptible (VISA and hetero-resistant (hVISA methicillin-resistantStaphylococcus aureus (MRSA remains uncertain because of their low frequency. In vitro attempts to generate reducedsusceptibility have been inconsistent. We describe a simple method for generating VISA/hVISA.Materials and methods: Twenty-four SCCmec type II and IV MRSA blood isolates plus USA100 and USA300 controls werecultured (107 CFU/ml in BHI broth with 0, 2 and 3 mg/L vancomycin for 10 days followed by 10 days vancomycin-freepassage.We monitored vancomycin minimum inhibitory concentration (MIC; Etest and population analysis profile-areaunder the curve (PAP-AUC ratios of tested isolate-Mu3 during and after vancomycin pressure (VP. PAP-AUC ratios 1.3 were considered consistent with susceptible, hVISA and VISA, respectively.Results: VP at 2 mg/L (VP-2 increased MIC to 3 mg/L in 20 (83.3% isolates and raised PAP-AUC ratio to hVISA (n=18; 75.0%and VISA (six; 25.0% ranges. VP-3 increased MIC to 3 and 4 mg/L in 19 (79.2% and three (12.5% isolates, respectively andraised PAP-AUC ratio to hVISA (n=3; 12.5% and VISA (n=19; 79.2% ranges. SCCmec IV isolates had lower pre-exposurePAP-AUC ratios (0.48±0.14 vs. 0.69±0.10; p<0.001 and lower MIC (1.6±0.2 vs. 1.8±0.2 mg/L; p=0.1 but MIC rise and VISA/hVISA emergence was comparable. MIC and PAP-AUC ratio rises were stable in 20/22 isolates during drug-free passages.Conclusions: VISA/hVISA readily emerges among MRSA SCCmec type II and IV isolates under VP. VP at the MIC level generateshVISA while pressure at slightly higher level results in the VISA phenotype. J Microbiol Infect Dis 2012; 2(4: 129-134Key words: Staphylococcus aureus; heteroresistance; glycopeptides; resistance; bacteremia.

High Glucose Concentration Promotes Vancomycin-Enhanced Biofilm Formation of Vancomycin-Non-Susceptible Staphylococcus aureus in Diabetic Mice.

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Chi-Yu Hsu

Full Text Available We previously demonstrated that vancomycin treatment increased acquisition of eDNA and enhanced biofilm formation of drug-resistant Staphylococcus aureus through a cidA-mediated autolysis mechanism. Recently we found that such enhancement became more significant under a higher glucose concentration in vitro. We propose that besides improper antibiotic treatment, increased glucose concentration environment in diabetic animals may further enhance biofilm formation of drug-resistant S. aureus. To address this question, the diabetic mouse model infected by vancomycin-resistant S. aureus (VRSA was used under vancomycin treatment. The capacity to form biofilms was evaluated through a catheter-associated biofilm assay. A 10- and 1000-fold increase in biofilm-bound bacterial colony forming units was observed in samples from diabetic mice without and with vancomycin treatment, respectively, compared to healthy mice. By contrast, in the absence of glucose vancomycin reduced propensity to form biofilms in vitro through the increased production of proteases and DNases from VRSA. Our study highlights the potentially important role of increased glucose concentration in enhancing biofilm formation in vancomycin-treated diabetic mice infected by drug-resistant S. aureus.

In vitro antimicrobial activity of linezolid tested against vancomycin-resistant enterococci isolated in Brazilian hospitals

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Reis Adriana O.

2001-01-01

Full Text Available The emergence of vancomycin-resistant enterococci (VRE has been described recently in Brazil. This is in contrast to the USA and Europe, where the VRE appeared in the late 1980s. The progressive increase in VRE isolation poses important problems in the antimicrobial therapy of nosocomial infections. Treatment options and effective antimicrobial agents for VRE are often limited and the possibility of transfer of vancomycin genes to other Gram-positive microorganisms continues. In the search for antimicrobial agents for multiresistant Gram-positive cocci, compounds such as linezolid and quinupristin/dalfopristin have been evaluated. The present study was conducted to evaluate the in vitro activity of the oxazolidinone linezolid and 10 other antimicrobial agents, including quinupristin-dalfopristin, against multiresistant enterococci isolated in Brazilian hospitals. Thirty-three vancomycin resistant isolates (17 Enterococcus faecium and 16 E. faecalis, were analyzed. Strains were isolated from patients at São Paulo Hospital, Oswaldo Cruz Hospital, Hospital do Servidor Público Estadual, Santa Marcelina Hospital, Santa Casa de Misericórdia de São Paulo, and Hospital de Clínicas do Paraná. The samples were tested by a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS recommendations. All isolates were molecular typed using pulsed-field gel electrophoresis (PFGE. Linezolid was the most active compound against these multiresistant enterococci, showing 100% inhibition at the susceptible breakpoints. Quinupristin/dalfopristin and teicoplanin showed poor activity against both species. The molecular typing results suggest that there has been interhospital spread of vancomycin resistant E. faecium and E. faecalis among Brazilian hospitals. The results of this study indicate that linezolid is an appropriate therapeutic option for the treatment of vancomycin-resistant enterococci infections in Brazil.

Vancomycin Utilization Evaluation: Are We Dosing Appropriately?

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Ladan Ayazkhoo

2015-10-01

Full Text Available Background: Inappropriate use of vancomycin not only increase health care costs but also contribute to the emergence of resistant organisms. Higher trough serum vancomycin concentrations (>10mg/L has been recommended for avoidance of development of resistance. We aim to compare the administered dose with recommended doses based on guideline-recommended weight-based dosing.Methods: In a cross sectional study, all patients who received vancomycin between July and October 2013, in infectious disease, internal medicine wards and emergency department of a teaching hospital in Tehran, Iran were entered to the study. Indication of vancomycin and necessary data for dose calculation including height and serum creatinine were recorded. Prescribed doses were compared with recommended doses in guidelines and calculated Glomerular filtration rate (GFR for each patient.Results: One hundred and four patients (45 females and 59 males recruited in the study. Our results indicated that, from all administered doses of vancomycin, 64.4% and 88.8% differs significantly (more than 20% based on American Pharmacist Association (AphA vancomycin monograph and guideline-recommended, weight-based vancomycin dosing (for adults, respectively.Conclusion: Underdosing of vancomycin is a major risk factor for developing resistance of gram positive organisms to this glycopeptide. Our results showed that more than half of patients receiving vancomycin are in the risk of low drug levels based on guidelines. So, having a comprehensive plan for the proper use of this drug especially designing effective internal guidelines can prevent emergence of resistance to vancomycin in future.

Persistence of vancomycin-resistant enterococci (VRE) in broiler houses after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Jensen, Lars Bogø

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in the EU in 1997 due to concern for the spread of vancomycin-resistant enterococci (VRE) from food animals to humans. In recent Norwegian and Danish studies, extensive occurrence of VRE on broiler farms and in broiler......, and disinfection of the houses between rotations, and two consecutive broiler flocks from each house were sampled by taking cloacal swabs from the broilers at the time of slaughter. A total of 69 vancomycin-resistant Enterococcus faecium isolates obtained from broiler flocks and broiler houses were subjected......-isolates from different broiler houses and from flocks reared in different houses appeared to be genetically unrelated. These findings indicated that VRE was transmitted between consecutive broiler flocks by clones of resistant. bacteria surviving in the broiler houses despite cleaning and disinfection between...

Frequency of Reduced Vancomycin Susceptibility among Clinical Staphylococcus aureus Isolated in Ahvaz Iran

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Mojtaba Moosavian

2015-11-01

Full Text Available Introduction:   One   of   the   most   important   agents   in   hospital-acquired   infections   is Staphylococcus aureus. Treatment of methicillin-resistant S. aureus (MRSA infections with decreased susceptibility to vancomycin has recently been more difficult. The aim of this study was to evaluate the possible presence of vancomycin intermediate S. aureus (VISA and vancomycin- resistant S. aureus (VRSA and also to determine the frequency of MRSA in clinical specimens.Methods: In this study, 195 S. aureus isolates were collected from the patients were examined. All of the isolates were identified using standard biochemical tests.  Susceptibility of S. aureus isolates against 10 antibiotics was detected by disk diffusion method and was followed by E-test and vancomycin screen agar methods. Minimum inhibitory concentration (MIC of vancomycin was determined according to the CLSI guidelines.  Also, detection of mecA gene was performed by PCR and finally, the results were compared.Results: All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was between 0.25-2 µg/ml. Out of 195 S. aureus isolates, 99 isolates (50.8% were resistant to methicillin, and mecA gene was detected in 96 isolates. These results also showed that the highest and lowest resistance rate of isolates was to penicillin (96.9% and chloramphenicol (0%, respectively.Conclusion: Our findings showed that vancomycin can still be used as a valuable drug for treatment of S. aureus infections in our region. However, periodic evaluation of vancomycin MIC of S. aureus isolates is critical for monitoring MRSA and preventing the spread of VISA or VRSA among patients.

Vancomycin-resistant enterococcus outbreak in a pediatric intensive care unit: report of successful interventions for control and prevention

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F. Carmona

2012-02-01

Full Text Available The objective of this study is to retrospectively report the results of interventions for controlling a vancomycin-resistant enterococcus (VRE outbreak in a tertiary-care pediatric intensive care unit (PICU of a University Hospital. After identification of the outbreak, interventions were made at the following levels: patient care, microbiological surveillance, and medical and nursing staff training. Data were collected from computer-based databases and from the electronic prescription system. Vancomycin use progressively increased after March 2008, peaking in August 2009. Five cases of VRE infection were identified, with 3 deaths. After the interventions, we noted a significant reduction in vancomycin prescription and use (75% reduction, and the last case of VRE infection was identified 4 months later. The survivors remained colonized until hospital discharge. After interventions there was a transient increase in PICU length-of-stay and mortality. Since then, the use of vancomycin has remained relatively constant and strict, no other cases of VRE infection or colonization have been identified and length-of-stay and mortality returned to baseline. In conclusion, we showed that a bundle intervention aiming at a strict control of vancomycin use and full compliance with the Hospital Infection Control Practices Advisory Committee guidelines, along with contact precautions and hand-hygiene promotion, can be effective in reducing vancomycin use and the emergence and spread of vancomycin-resistant bacteria in a tertiary-care PICU.

Evaluation of vancomycin MIC creep in Staphylococcus aureus.

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Diaz, Raquel; Ramalheira, Elmano; Afreixo, Vera; Gago, Bruno

2017-09-01

Vancomycin is the primary treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing proportion of MRSA isolates with high minimum inhibitory concentrations (MICs) within the susceptible range (vancomycin 'MIC creep') is being observed. The aim of this study was to assess the vancomycin MIC distribution for S. aureus isolates over a period of 4 years in Centro Hospitalar Baixo Vouga (Aveiro, Portugal) and to identify differences in vancomycin MIC determined by different susceptibility testing methods. For each S. aureus isolate, the vancomycin MIC was assayed by the VITEK ® 2 automated system and the broth microdilution testing method. The results showed significant differences in vancomycin MIC by different methods (P=0.021, sign test) and did not suggest the presence of vancomycin MIC creep during the study period. Vancomycin MIC creep is a regional problem, therefore it can only be assessed through the evaluation of local susceptibility profiles, and antibiogram based on real MIC assay should be an essential element in local MRSA infection clinical management. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Identification and molecular characterization of Van A-type vancomycin-resistant Enterococcus faecalis in Northeast of Brazil

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Marinalda Anselmo Vilela

2006-11-01

Full Text Available The isolation of vancomycin resistant enterococci (VRE in Brazil has rapidly increased, following the world wide tendency. We report in the present study the first isolation of vancomycin resistant Enterococcus faecalis (VRE in the Northeast of Brazil. The four VRE isolates were characterized for antimicrobial susceptibility, genotypic typing by macro restriction of chromosomal DNA followed by pulsed-field gel electrophoresis and for characterization of the Tn1546-like element and plasmid contents. The isolates showed resistance to multiple antibiotics and a single genotype profile, suggesting the dissemination of a single clone among the patients. Tn1546 associated to genetic elements as plasmids shows the importance of infection control measures to avoid the spreading of glycopetide resistance by conjugative transfer of VanA elements.

In Vitro Synergistic Effects of Double and Triple Combinations of β-Lactams, Vancomycin, and Netilmicin against Methicillin-Resistant Staphylococcus aureus Strains

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Rochon-Edouard, Stéphanie; Pestel-Caron, Martine; Lemeland, Jean-François; Caron, François

2000-01-01

Several studies have previously reported synergistic effects between vancomycin and a given β-lactam or a given aminoglycoside against methicillin-resistant Staphylococcus aureus (MRSA) strains. The aim of our study was to exhaustively compare the effects of different combinations of a β-lactam, vancomycin, and/or an aminoglycoside against 32 clinical MRSA strains with different aminoglycoside susceptibility patterns. The effects of 26 different β-lactam–vancomycin and 8 different aminoglycoside-vancomycin combinations were first studied using a disk diffusion screening method. The best interactions with vancomycin were observed with either imipenem, cefazolin, or netilmicin. By checkerboard studies, imipenem-vancomycin and cefazolin-vancomycin each provided a synergistic bacteriostatic effect against 22 strains; the mean fractional inhibitory concentration (FIC) indexes were 0.35 and 0.46 for imipenem-vancomycin and cefazolin-vancomycin, respectively. The vancomycin-netilmicin combination provided an indifferent effect against all of the 32 strains tested; the mean of FIC index was 1.096. The mean concentrations of imipenem, cefazolin, netilmicin, and vancomycin at which FIC indexes were calculated were clinically achievable. Killing experiments were then performed using imipenem, cefazolin, netilmicin, and vancomycin at one-half of the MIC, alone and in different combinations, against 10 strains. The vancomycin-netilmicin regimen was rarely bactericidal, even against strains susceptible to netilmicin. The imipenem-vancomycin and cefazolin-vancomycin combinations were strongly bactericidal against six and five strains, respectively. The addition of netilmicin markedly enhanced the killing activity of the combination of cefazolin or imipenem plus vancomycin, but only for the MRSA strains against which the β-lactam–vancomycin combinations had no bactericidal effect. It is noteworthy that the latter strains were both susceptible to netilmicin and

Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

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Rehm, Susan J; Tice, Alan

2010-09-15

The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

Dispersion of the vancomycin resistance genes vanA and vanC of Enterococcus isolated from Nile tilapia on retail sale: A public health hazard

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Kamelia Mahmoud Osman

2016-08-01

Full Text Available Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC as well as the presence of enterococcal surface protein (esp using conventional and molecular methods. The cultural, biochemical (Vitek 2 system and PCR results revealed eight Enterococcus isolates from the 80 fish samples (10% to be further identified as E. faecalis (6/8, 75% and E gallinarum (2/8, 25%. Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70% within 3 days and 100% mortality at 6 days post injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasise the potential role

Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis

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Sadeghifard, Nourkhoda

2015-07-01

Full Text Available Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of and O157H7 in ground meat in Ilam, Iran. Both index organisms were identified following standard food microbiological methods. For , the susceptibility to vancomycin was tested, and PCR was used to check for the gene. was present in all 24 ground meat samples, with no O157H7 detected in samples. The analysis showed the presence of the gene in 5/24 vancomycin resistant enterococci. In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future.

Delayed-Onset Post-Keratoplasty Endophthalmitis Caused by Vancomycin-Resistant Enterococcus faecium

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Julio C. Hernandez-Camarena

2012-10-01

Full Text Available Background: Vancomycin-resistant Enterococcus (VRE endophthalmitis after penetrating keratoplasty (PKP is very rare, the management is a challenge due to both the pattern of antibiotic resistance and the aggressive nature of the infectious process. We report the first delayed-onset case of VRE endophthalmitis after PKP. Materials and Methods: Case report of a 51-year-old female with a 7-week history of PKP who arrived at the emergency room with signs and symptoms of endophthalmitis. Initial visual acuity was light perception, and a posterior pole exam was not possible due to the intense vitreous reaction. Mode B ultrasound was used to assess the posterior pole. The patient underwent pars plana vitrectomy and received intravitreous antibiotics. Results: Vitreous stains and cultures were positive for Enterococcus faecium resistant to vancomycin. Donor rim cultures and viral PCR were negative. Treatment was carried out by repeated intravitreal antibiotics and systemic linezolid. Clinical improvement was seen after the second dose of intravitreous antibiotics and systemic linezolid, but visual acuity remained at light perception consistent with the ischemic changes observed in the posterior pole. Conclusion: VRE endophthalmitis might be associated with positive donor rim cultures. Prompt use of systemic linezolid in addition to intravitreous antibiotics is recommendable, but even with prompt treatment, visual prognosis is guarded.

Healthcare-associated vancomycin resistant Enterococcus faecium infections in the Mansoura University Hospitals intensive care units, Egypt

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Dalia Moemen

2015-09-01

Full Text Available 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.

Weissella confusa: a rare cause of vancomycin-resistant Gram-positive bacteraemia.

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Kumar, Anil; Augustine, Deepthi; Sudhindran, S; Kurian, Anu M; Dinesh, Kavitha R; Karim, Shamsul; Philip, Rosamma

2011-10-01

We describe a case of bacteraemia caused by Weissella confusa in a 48-year-old male who was operated on for adenocarcinoma of the gastro-oesophageal junction and maintained on total parenteral nutrition. Blood cultures were positive for a vancomycin-resistant streptococcus-like organism which was identified as W. confusa by 16S rRNA gene sequencing.

Nurses' experience with vancomycin-resistant enterococci (VRE).

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Mitchell, Ann; Cummins, Teresa; Spearing, Natalie; Adams, June; Gilroy, Lisa

2002-01-01

The emergence and spread of resistant organisms, in particular vancomycin-resistant enterococci (VRE), is an issue facing all staff in acute hospitals. This study explored how nurses coped with the responsibility of halting further spread of this organism during an outbreak. VRE-positive patients were cohorted with nurses who cared for them in an endeavour to contain the spread of VRE. The majority of nurses found the situation extremely stressful because of the need to act as 'gatekeepers' responsible for educating and monitoring the practices of staff and visitors. The nurses reported that they felt they were inadequately supported, were blamed for the outbreak, and that they had an increased workload as they took on duties of other staff. The results reinforce the need for a multidisciplinary team approach to education and control of VRE, more support for nursing staff cohorted with VRE-positive patients, and stringent adherence to infection control measures by all hospital staff.

Role of the transmembrane domain of the VanT serine racemase in resistance to vancomycin in Enterococcus gallinarum BM4174.

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Arias, C A; Peña, J; Panesso, D; Reynolds, P

2003-03-01

Enterococcus gallinarum BM4175 (a vancomycin-susceptible derivative of BM4174 obtained by insertional inactivation of vanC-1) was transformed with plasmid constructs pCA10 (containing the genes necessary for resistance, vanC-1-XYc-T), pJP1 (with a fragment lacking the DNA encoding the transmembrane region of VanT, -vanC-1-XYc-T((Delta))(2-322)-) and with plasmids containing fragments encoding either the transmembrane (mvanT(1-322)) or racemase (svanT(323-698)) domains of VanT under the control of a constitutive promoter. Accumulated peptidoglycan precursors were measured in all strains in the presence of L-Ser, D-Ser (50 mM) or in the absence of any growth supplement. Uptake of 0.1 mM L-[(14)C]serine was also determined in BM4174, BM4175 and BM4175/pCA10. Vancomycin resistance was restored in BM4175 transformed with pCA10(C-1-XYc-T), and the profile of peptidoglycan precursors was similar to wild-type E. gallinarum BM4174. Transformation of E. gallinarum BM4175 with plasmid pJP1(vanC-1-XYc-T((Delta))(2-322)) resulted in: (i) vancomycin MICs remaining within susceptible levels (VanT is likely to be involved in the transport of L-Ser, and that in its absence the resistance phenotype is compromised.

Vancomycin-resistant enterococci (VRE) in broiler flocks 5 years after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in Denmark in 1995. In this study, we investigated the occurrence of vancomycin-resistant enterococci (VRE) in broiler flocks in the absence of the selective pressure exerted by the use of avoparcin. One hundred sixty...

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

Energy Technology Data Exchange (ETDEWEB)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); Gibbs, Shawn G. [Department of Environmental Health, School of Public Health-Bloomington, Indiana University, Bloomington, IN (United States); Claye, Emma [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); He, Xin [Department of Epidemiology and Biostatistics, University of Maryland School of Public Health, College Park, MD (United States); Sapkota, Amy R., E-mail: ars@umd.edu [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States)

2016-05-15

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

International Nuclear Information System (INIS)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg; Gibbs, Shawn G.; Claye, Emma; He, Xin; Sapkota, Amy R.

2016-01-01

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

Stimulated phase-shift acoustic nanodroplets enhance vancomycin efficacy against methicillin-resistant Staphylococcus aureus biofilms

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Guo H

2017-06-01

Full Text Available Hao Guo,1 Ziming Wang,1 Quanyin Du,1 Pan Li,2 Zhigang Wang,2 Aimin Wang1 1Department of Orthopedics, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China; 2Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China Purpose: Bacterial biofilms on the surface of prostheses are becoming a rising concern in managing prosthetic joint infections. The inherent resistant features of biofilms render traditional antimicrobial therapy unproductive and revision surgery outcomes uncertain. This situation has prompted the exploration of novel antimicrobial strategies. The synergy of ultrasound microbubbles and vancomycin has been proposed as an efficient alternative for biofilm eradication. The purpose of this study was to evaluate the anti-biofilm effect of stimulated phase-shift acoustic nanodroplets (NDs combined with vancomycin.Materials and methods: We fabricated lipid phase-shift NDs with a core of liquid perfluoropentane. A new phase change mode for NDs incorporating an initial unfocused low-intensity pulsed ultrasound for 5 minutes and a subsequent incubation at 37°C into a 24-hour duration was developed. Methicillin-resistant Staphylococcus aureus (MRSA biofilms were incubated with vancomycin and NDs under the hybrid stimulation. Biofilm morphology following treatment was determined using confocal laser scanning microscopy and scanning electron microscopy. Resazurin assay was used to quantify bactericidal efficacy against MRSA biofilm bacteria.Results: NDs treated sequentially with ultrasound and heating at 37°C achieved gradual and substantial ND vaporization and cavitation in a successive process. NDs after stimulation were capable of generating stronger destruction on biofilm structure which was best characterized by residual circular arc margins and more dead bacteria. Furthermore, NDs

Synergy of β-Lactams with Vancomycin against Methicillin-Resistant Staphylococcus aureus: Correlation of Disk Diffusion and Checkerboard Methods.

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Sy, Cheng Len; Huang, Tsi-Shu; Chen, Chii Shiang; Chen, Yao-Shen; Tsai, Hung-Chin; Wann, Shue-Renn; Wu, Kuan-Sheng; Chen, Jui-Kuang; Lee, Susan Shin-Jung; Liu, Yung-Ching

2016-03-01

Modified disk diffusion (MDD) and checkerboard tests were employed to assess the synergy of combinations of vancomycin and β-lactam antibiotics for 59 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Mu50 (ATCC 700699). Bacterial inocula equivalent to 0.5 and 2.0 McFarland standard were inoculated on agar plates containing 0, 0.5, 1, and 2 μg/ml of vancomycin. Oxacillin-, cefazolin-, and cefoxitin-impregnated disks were applied to the surface, and the zones of inhibition were measured at 24 h. The CLSI-recommended checkerboard method was used as a reference to detect synergy. The MICs for vancomycin were determined using the Etest method, broth microdilution, and the Vitek 2 automated system. Synergy was observed with the checkerboard method in 51% to 60% of the isolates when vancomycin was combined with any β-lactam. The fractional inhibitory concentration indices were significantly lower in MRSA isolates with higher vancomycin MIC combinations (P synergy in MRSA isolates with bacterial inocula equivalent to McFarland standard 0.5 were 33.0% and 62.5% for oxacillin, 45.1% and 52.4% for cefazolin, and 43.1% and 52.4% for cefoxitin when combined with 0.5 and 2 μg/ml of vancomycin, respectively. Based on our study, the simple MDD method is not recommended as a replacement for the checkerboard method to detect synergy. However, it may serve as an initial screening method for the detection of potential synergy when it is not feasible to perform other labor-intensive synergy tests. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Short communication: β-Lactam resistance and vancomycin heteroresistance in Staphylococcus spp. isolated from bovine subclinical mastitis.

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Mello, Priscila Luiza; Pinheiro, Luiza; Martins, Lisiane de Almeida; Brito, Maria Aparecida Vasconcelos Paiva; Ribeiro de Souza da Cunha, Maria de Lourdes

2017-08-01

The use of antimicrobial agents has led to the emergence of resistant bacterial strains over a relatively short period. Furthermore, Staphylococcus spp. can produce β-lactamase, which explains the survival of these strains in a focus of infection despite the use of a β-lactam antibiotic. The aim of this study was to evaluate the resistance of Staphylococcus spp. isolated from bovine subclinical mastitis to oxacillin and vancomycin (by minimum inhibitory concentration) and to detect vancomycin heteroresistance by a screening method. We also evaluated β-lactamase production and resistance due to hyperproduction of this enzyme and investigated the mecA and mecC genes and performed staphylococcal cassette chromosome mec typing. For this purpose, 181 Staphylococcus spp. isolated from mastitis subclinical bovine were analyzed. Using the phenotypic method, 33 (18.2%) of Staphylococcus spp. were resistant to oxacillin. In contrast, all isolates were susceptible to vancomycin, and heteroresistance was detected by the screening method in 13 isolates. Production of β-lactamase was observed in 174 (96%) of the Staphylococcus spp. isolates. The mecA gene was detected in 8 isolates, all of them belonging to the species Staphylococcus epidermidis, and staphylococcal cassette chromosome mec typing revealed the presence of type I and type IV isolates. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Cross-transmission of vancomycin-resistant Enterococcus in patients undergoing dialysis and kidney transplant

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D. Fram

2010-01-01

Full Text Available The objective of this study was to investigate the occurrence of vancomycin-resistant Enterococcus (VRE cross-transmission between two patient groups (long-term dialysis and kidney transplant patients. Molecular typing, by automated ribotyping with the RiboPrinter Microbial Characterization System (Qualicon, USA, was used to analyze VRE isolates from 31 fecal samples of 320 dialysis patients and 38 fecal samples of 280 kidney transplant patients. Clonal spread of E. faecalis and E. casseliflavus was observed intragroup, but not between the two groups of patients. In turn, transmission of E. gallinarum and E. faecium between the groups was suggested by the finding of vancomycin-resistant isolates belonging to the same ribogroup in both dialysis and transplant patients. The fact that these patients were colonized by VRE from the same ribogroup in the same health care facility provides evidence for cross-transmission and supports the adoption of stringent infection control measures to prevent dissemination of these bacteria.

Indications for vancomycin in dialysis patients.

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Golper, T A; Schulman, G; D'Agata, E M

2000-01-01

Resistance to vancomycin has emerged among Staphylococcus aureus, coagulase-negative staphylococci (CNS), and enterococci, and this emergence has particular prevalence in dialysis units. It has therefore become imperative that physicians use vancomycin judiciously. General recommendations regarding the appropriate use of vancomycin have been developed. Although in theory implementation of these guidelines should not be difficult, the medical community may be unable or unwilling to make the necessary adjustments in practice. The onslaught of cost constraints and bureaucratic encumbrance has occurred simultaneously with the increase in vancomycin resistance among pathogens commonly isolated among the dialysis population. When a patient responds to empiric antibiotic therapy and susceptibility data indicate that an antibiotic other than vancomycin would be appropriate, the clinician far too often does not make the change to this alternative. Previously there was no biological imperative to change the antibiotic. That complacency has infected an entire generation of physicians, and especially nephrologists. Furthermore, there is an active movement against change, driven by concerns such as malpractice accusations and frank errors in the interpretation of medical facts.

Typing of vancomycin-resistant enterococci from Danish hospitals

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Lester, C H; Olsen, S S; Schønheyder, Henrik Carl

2009-01-01

locus sequence typing (MLST) was performed on the vancomycin-resistant E. faecium isolates. Results: The collection consisted of 45 E. faecium and 16 E. faecalis isolates which originated from 12 different hospitals. Thirty three of 45 E. faecium isolates were vanA positive and the remaining 12 isolates...... were vanB positive. All but one of the E. faecalis isolates contained the vanB gene (n = 15) and the remaining isolate contained the vanA gene. MLST of the 45 E. faecium isolates revealed 10 different sequence types (ST). The STs were ST18 (n = 21), ST203 (n = 8), ST78 (n = 3), ST192 (n = 3), ST412 (n...

Nanoconjugated vancomycin: new opportunities for the development of anti-VRSA agents

International Nuclear Information System (INIS)

Chakraborty, Subhankari Prasad; Mahapatra, Santanu Kar; Roy, Somenath; Sahu, Sumanta Kumar; Santra, Susmita; Pramanik, Panchanan; Bal, Manjusri

2010-01-01

More than 90% of Staphylococcus strains are resistant to penicillin. In 1961 S. aureus developed resistance to methicillin (MRSA), invalidating almost all antibiotics, including the most potent β-lactams. Vancomycin, a glycopeptide antibiotic, was used for the treatment of MRSA in 1980. Vancomycin inhibits the bio-synthesis of peptidoglycan and the assembly of NAM-NAG-polypeptide into the growing peptidoglycan chain. Vancomycin resistant S. aureus (VRSA) first appeared in the USA in 2002. Folic acid tagged chitosan nanoparticles are used as Trojan horses to deliver vancomycin into bacterial cells. These nanoparticles are biocompatible and biodegradable semisynthetic polymers. These nanosized vehicles enhance the transport of vancomycin across epithelial surfaces and show its efficient drug action, which has been understood from studies of the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles of a chitosan derivative loaded with vancomycin. Tolerance values distinctly show that vancomycin loaded into nanoconjugate is very effective and has a strong bactericidal effect on VRSA.

Nanoconjugated vancomycin: new opportunities for the development of anti-VRSA agents

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Chakraborty, Subhankari Prasad; Mahapatra, Santanu Kar; Roy, Somenath [Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore-721102 (India); Sahu, Sumanta Kumar; Santra, Susmita; Pramanik, Panchanan [Nanomaterials Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur, Pin-721302 (India); Bal, Manjusri, E-mail: panchanan_123@yahoo.com [Department of Human Physiology, Calcutta University, Kolkata (India)

2010-03-12

More than 90% of Staphylococcus strains are resistant to penicillin. In 1961 S. aureus developed resistance to methicillin (MRSA), invalidating almost all antibiotics, including the most potent {beta}-lactams. Vancomycin, a glycopeptide antibiotic, was used for the treatment of MRSA in 1980. Vancomycin inhibits the bio-synthesis of peptidoglycan and the assembly of NAM-NAG-polypeptide into the growing peptidoglycan chain. Vancomycin resistant S. aureus (VRSA) first appeared in the USA in 2002. Folic acid tagged chitosan nanoparticles are used as Trojan horses to deliver vancomycin into bacterial cells. These nanoparticles are biocompatible and biodegradable semisynthetic polymers. These nanosized vehicles enhance the transport of vancomycin across epithelial surfaces and show its efficient drug action, which has been understood from studies of the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles of a chitosan derivative loaded with vancomycin. Tolerance values distinctly show that vancomycin loaded into nanoconjugate is very effective and has a strong bactericidal effect on VRSA.

Transposon characterization of vancomycin-resistant Enterococcus faecium (VREF) and dissemination of resistance associated with transferable plasmids

DEFF Research Database (Denmark)

Migura, Lourdes Garcia; Liebana, Ernesto; Jensen, Lars Bogø

2007-01-01

Objectives: VanA glycopeptide resistance has persisted on broiler farms in the UK despite the absence of the antimicrobial selective pressure, avoparcin. This study aimed to investigate the contribution of horizontal gene transfer of Tn 1546 versus clonal spread in the dissemination of the resist......Objectives: VanA glycopeptide resistance has persisted on broiler farms in the UK despite the absence of the antimicrobial selective pressure, avoparcin. This study aimed to investigate the contribution of horizontal gene transfer of Tn 1546 versus clonal spread in the dissemination...... plasmid replicons, associated with antimicrobial resistance on several unrelated farms. Conclusions: Horizontal transfer of vancomycin resistance may play a more important role in the persistence of antimicrobial resistance than clonal spread. The presence of different plasmid replicons, associated...... with antimicrobial resistance on several unrelated farms, illustrates the ability of these enterococci to acquire and disseminate mobile genetic elements within integrated livestock systems....

Vancomycin Molecular Interactions: Antibiotic and Enantioselective Mechanisms

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Ward, Timothy J.; Gilmore, Aprile; Ward, Karen; Vowell, Courtney

Medical studies established that vancomycin and other related macrocyclic antibiotics have an enhanced antimicrobial activity when they are associated as dimers. The carbohydrate units attached to the vancomycin basket have an essential role in the dimerization reaction. Covalently synthesized dimers were found active against vancomycin-resistant bacterial strains. A great similarity between antibiotic potential and enantioselectivity was established. A covalent vancomycin dimer was studied in capillary electrophoresis producing excellent chiral separation of dansyl amino acids. Balhimycin is a macrocyclic glycopeptide structurally similar to vancomycin. The small differences are, however, responsible for drastic differences in enantioselectivity in the same experimental conditions. Contributions from studies examining vancomycin's mechanism for antimicrobial activity have substantially aided our understanding of its mechanism in chiral recognition.

Phenotypic changes of methicillin-resistant Staphylococcus aureus during vancomycin therapy for persistent bacteraemia and related clinical outcome.

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Kim, T; Kim, E S; Park, S Y; Sung, H; Kim, M-N; Kim, S-H; Lee, S-O; Choi, S-H; Jeong, J-Y; Woo, J H; Chong, Y P; Kim, Y S

2017-08-01

Persistent bacteraemia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) that fails to respond to glycopeptide therapy is a well-documented clinical problem. There are limited data on changes in agr functionality, vancomycin susceptibility and heteroresistance during MRSA PB. Thus, the frequency of these changes and their clinical significance remain unclear. Only patients with MRSA PB (≥7 days) from a prospective cohort of S. aureus bacteraemia were included. We collected isogenic paired strains and compared vancomycin MIC, vancomycin heteroresistance, and agr functionality between initial and final blood isolates. We also assessed the clinical outcome. A total of 49 patients had MRSA PB over 22 months. Bacteraemia persisted for a median of 13 days and most patients (98%) received glycopeptide as initial therapy. Among 49 isogenic pairs, only one pair showed a vancomycin MIC increase ≥2-fold by broth microdilution method, and only seven (14%) by E-test. Significant portions of initial isolates had vancomycin heteroresistance (49%) and agr dysfunction (76%). Development of vancomycin heteroresistance during PB occurred in four (16%) among 25 initial vancomycin-susceptible isolates, and acquisition of agr dysfunction occurred in two (16%) among 12 initial agr-functional isolates. Changes in the opposite direction occasionally occurred. These phenotypic changes during PB were not associated with mortality, whereas agr dysfunction of the initial isolates was significantly associated with mortality. During MRSA PB, phenotypic changes of MRSA isolates occurred occasionally under prolonged vancomycin exposure but were not significantly associated with clinical outcome. In contrast, initial agr dysfunction could be a predictor for mortality in MRSA PB.

Typing of vancomycin-resistant enterococci with MALDI-TOF mass spectrometry in a nosocomial outbreak setting

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Holzknecht, B J; Dargis, R; Pedersen, M

2018-01-01

OBJECTIVES: To investigate the usefulness of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) typing as a first-line epidemiological tool in a nosocomial outbreak of vancomycin-resistant Enterococcus faecium (VREfm). METHODS: Fifty-five VREfm isolates...

Annual Surveillance Summary: Vancomycin-Resistant Enterococci (VRE) Infections in the Military Health System (MHS), 2015

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2017-03-01

Oregon, Washington, Idaho, Montana, Wyoming, Colorado, New Mexico , Arizona, Utah, Nevada, Alaska, Hawaii. • South: Texas, Oklahoma, Arkansas, Louisiana... Diabetes and Digestive and Kidney Diseases. Washington, DC. 2007; 587–620. 27. Milburn E, Chukwuma U. Vancomycin-resistant Enterococci infections in

Evaluation of risk factors for vancomycin-induced nephrotoxicity.

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Park, So Jin; Lim, Na Ri; Park, Hyo Jung; Yang, Jae Wook; Kim, Min-Ji; Kim, Kyunga; In, Yong Won; Lee, Young Mee

2018-05-09

Background Vancomycin is a glycopeptide antibiotic of choice for the treatment of serious infections caused by multi-resistant Gram-positive bacteria. However, vancomycin-associated nephrotoxicity (VAN) often limits its use. Previous data suggested a few risk factors of VAN, including higher mean vancomycin trough level, higher daily doses, old age, long duration of vancomycin therapy, and concomitant nephrotoxins. Objective To evaluate the incidence and risk factors of VAN and determine whether higher vancomycin trough concentrations were associated with a greater risk for VAN. Settings A retrospective, observational, single-center study at the 1960-bed university-affiliated tertiary care hospital (Samsung Medical Center), Seoul, Korea. Method A retrospective analysis of adult patients who received vancomycin parenterally in a tertiary care medical center from March 1, 2013 to June 30, 2013 was performed. We excluded patients with a baseline serum creatinine level > 2 mg/dL and those who had a history of end-stage renal disease and dialysis at baseline. The clinical characteristics were compared between patients with nephrotoxicity and those without nephrotoxicity to identify the risk factors associated with VAN. Main outcome measure Incidence of VAN and VAN-associated risk factors were analyzed. Results Of the 315 vancomycin-treated patients, nephrotoxicity occurred in 15.2% of the patients. In multivariate analysis, higher vancomycin trough concentrations of > 20 mg∕L (OR 9.57, 95% CI 2.49-36.83, p < 0.01) and intensive care unit (ICU) residence (OR 2.86, 95% CI 1.41-5.82, p < 0.01) were independently associated with VAN. Conclusion Our findings suggest that higher vancomycin trough levels and ICU residence might be associated with a greater risk for VAN. More careful monitoring of vancomycin serum trough levels and patient status might facilitate the timely prevention of VAN.

Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

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Erginkaya, Z; Turhan, E U; Tatlı, D

2018-01-01

In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

Vancomycin resistant enterococci (VRE in Swedish sewage sludge

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Aspan Anna

2009-05-01

Full Text Available Abstract Background Antimicrobial resistance is a serious threat in veterinary medicine and human healthcare. Resistance genes can spread from animals, through the food-chain, and back to humans. Sewage sludge may act as the link back from humans to animals. The main aims of this study were to investigate the occurrence of vancomycin resistant enterococci (VRE in treated sewage sludge, in a Swedish waste water treatment plant (WWTP, and to compare VRE isolates from sewage sludge with isolates from humans and chickens. Methods During a four month long study, sewage sludge was collected weekly and cultured for VRE. The VRE isolates from sewage sludge were analysed and compared to each other and to human and chicken VRE isolates by biochemical typing (PhenePlate, PFGE and antibiograms. Results Biochemical typing (PhenePlate-FS and pulsed field gel electrophoresis (PFGE revealed prevalence of specific VRE strains in sewage sludge for up to 16 weeks. No connection was found between the VRE strains isolated from sludge, chickens and humans, indicating that human VRE did not originate from Swedish chicken. Conclusion This study demonstrated widespread occurrence of VRE in sewage sludge in the studied WWTP. This implies a risk of antimicrobial resistance being spread to new farms and to the society via the environment if the sewage sludge is used on arable land.

Emergence in Asian Countries of Staphylococcus aureus with Reduced Susceptibility to Vancomycin

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Song, Jae-Hoon; Hiramatsu, Keiichi; Suh, Ji Yoeun; Ko, Kwan Soo; Ito, Teruyo; Kapi, Maria; Kiem, Sungmin; Kim, Yeon-Sook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2004-01-01

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediately resistant to vancomycin (hVISA) was confirmed by population analysis. Of 347 (25.6%) MRSA isolates that grew on the screening agar plates, 58 isolates (4.3%) were hVISA. hVISA strains were found in India, South Korea, Japan, the Philippines, Singapore, Thailand, and Vietnam. However, neither vancomycin-intermediate S. aureus nor vancomycin-resistant S. aureus isolates were found among MRSA isolates from Asian countries in this survey. PMID:15561884

Vancomycin-Resistance Enterococci Infections in the Department of the Defense: Annual Report 2013

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2014-08-01

str.r.:lioos, S€’ £l "r:’hi fl!’:: lil<i~lin ,:l ddc ~o.r-c.;s, !]:l:ho:>r rr:, aY. nflinttlirir~ :he !::f;, ·nod c ol ’ HO: Io ~:·rnhlir’U ;;· ;d ro...16. Morris JG, et al. Enterococci resistant to multiple antimicrobial agents, including vancomycin: establishment of endemicity in a university

Molecular characterization of vancomycin-intermediate Staphylococcus aureus isolates from Tehran

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Shahin Najar-Peerayeh

2016-09-01

Full Text Available Objective: To determine the prevalence and some genetic characteristics of clinical isolates of Staphylococcus aureus (S. aureus with reduced susceptibility to vancomycin. Methods: A total of 414 isolates of S. aureus were collected from clinical specimens from hospitals in Tehran. Vancomycin-intermediate S. aureus (VISA was determined by brain heart infusion agar containing 4 μg/mL vancomycin screening plate and confirmed via E-test. VISA isolates were analysed for vanA, vanB, mecA, staphylococcal cassette chromosome mec types, surface protein A (Spa types and agr specific groups. Results: Brain heart infusion agar containing 4 μg/mL vancomycin screening tests revealed that 17.14% (n = 71 of S. aureus isolates were VISA phenotype. Ten of the 71 isolates were confirmed by E-test method (minimal inhibitory concentration was 4 to 8 μg/mL. All VISA isolates were susceptible to linezolid and 6 isolates (60% were methicillin-resistant S. aureus. Five isolates belonged to agr Group II, 4 belonged to agr Group I and 1 belonged to agr Group III. Spa type t030, and staphylococcal cassette chromosome mec Type III were dominant among VISA isolates. Conclusions: This study provides further evidence of the global dissemination of VISA isolates and emphasizes to vancomycin susceptibility testing prior to antibiotic therapy.

Crystallization and preliminary X-ray analysis of a d-Ala:d-Ser ligase associated with VanG-type vancomycin resistance

International Nuclear Information System (INIS)

Weber, Patrick; Meziane-Cherif, Djalal; Haouz, Ahmed; Saul, Frederick A.; Courvalin, Patrice

2009-01-01

The VanG d-alanine:d-serine ligase was crystallized in complex with ADP and diffraction data were collected at 2.35 Å resolution. Acquired VanG-type resistance to vancomycin in Enterococcus faecalis BM4518 arises from inducible synthesis of peptidoglycan precursors ending in d-alanyl-d-serine, to which vancomycin exhibits low binding affinity. VanG, a d-alanine:d-serine ligase, catalyzes the ATP-dependent synthesis of the d-Ala-d-Ser dipeptide, which is incorporated into the peptidoglycan synthesis of VanG-type vancomycin-resistant strains. Here, the purification, crystallization and preliminary crystallographic analysis of VanG in complex with ADP are reported. The crystal belonged to space group P3 1 21, with unit-cell parameters a = b = 116.1, c = 177.2 Å, and contained two molecules in the asymmetric unit. A complete data set has been collected to 2.35 Å resolution from a single crystal under cryogenic conditions using synchrotron radiation

Empiric guideline-recommended weight-based vancomycin dosing and mortality in methicillin-resistant Staphylococcus aureus bacteremia: a retrospective cohort study

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Hall Ronald G

2012-04-01

Full Text Available Abstract Background No studies have evaluated the effect of guideline-recommended weight-based dosing on in-hospital mortality of patients with methicillin-resistant Staphylococcus aureus bacteremia. Methods This was a multicenter, retrospective, cohort study of patients with methicillin-resistant Staphylococcus aureus bacteremia receiving at least 48 hours of empiric vancomycin therapy between 01/07/2002 and 30/06/2008. We compared in-hospital mortality for patients treated empirically with weight-based, guideline-recommended vancomycin doses (at least 15 mg/kg/dose to those treated with less than 15 mg/kg/dose. We used a general linear mixed multivariable model analysis with variables identified a priori through a conceptual framework based on the literature. Results A total of 337 patients who were admitted to the three hospitals were included in the cohort. One-third of patients received vancomycin empirically at the guideline-recommended dose. Guideline-recommended dosing was not associated with in-hospital mortality in the univariable (16% vs. 13%, OR 1.26 [95%CI 0.67-2.39] or multivariable (OR 0.71, 95%CI 0.33-1.55 analysis. Independent predictors of in-hospital mortality were ICU admission, Pitt bacteremia score of 4 or greater, age 53 years or greater, and nephrotoxicity. Conclusions Empiric use of weight-based, guideline-recommended empiric vancomycin dosing was not associated with reduced mortality in this multicenter study.

Prevalence of Methicillin and Vancomycin resistant Staphylococcus aureus colonization in nasopharynx; Amir-Alam hospital, 2005

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Hasibi M

2007-07-01

Full Text Available Background: Staphylococcus aureus is one of the most common causes of nosocomial infections with high morbidity and mortality rate. Traditionally, methicillin resistant staphylococcus aureus has been considered a major nosocomial pathogen in healthcare facilities, but in the past decade, it has been observed emerging in the community as well. Informations regarding hospital microbial colonization could be an important step for prevention of nosocomial infections. Our objective was clarifying the prevalence of methicillin resistant and vancomycin resistant staphylococcus aureus colonization in nasopharynx. Methods: A descriptive cross sectional study was carried on 106 patients and nursing staff of surgery and hemodialysis wards in Amir-Alam hospital from April 2005 to July 2005. The samples were collected from nasal region of cases using cotton swab by two experienced technician and were sent to laboratory for culture and antibiogram. Results: Twenty six (29.5% out of 106 cases were nasopharyngeal carriers of staphylococcus aureus. Eight cases (7.5% had methicillin resistant staphylococcus aureus. The most frequent colonization rate was seen in hemodialysis nursing staff and in all of them methicillin resistant staphylococcus aureus was reported. Carrier rates in hemodialysis patients were twice compared to surgery ward patients. The interesting point was that no sample of vancomycin resistant staphylococcus aureus was isolated. Conclusion: Prevalence of methicillin resistant staphylococcus aureus colonization seems to be increased; therefore proper management for controlling this problem is mandatory. The results of the present study suggest that the prevalence of methicillin resistant staphylococcus aureus infections is higher than was expected in Iran and vigorous preventive strategies should therefore be taken to stop the growth of this major health problem.

Phenotypic and genotypic characterization of vancomycin-resistant Enterococcus faecium clinical isolates from two hospitals in Mexico: First detection of VanB phenotype-vanA genotype.

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Bocanegra-Ibarias, Paola; Flores-Treviño, Samantha; Camacho-Ortiz, Adrián; Morfin-Otero, Rayo; Villarreal-Treviño, Licet; Llaca-Díaz, Jorge; Martínez-Landeros, Erik Alan; Rodríguez-Noriega, Eduardo; Calzada-Güereca, Andrés; Maldonado-Garza, Héctor Jesús; Garza-González, Elvira

2016-01-01

Enterococcus faecium has emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. Our aim was to determine the antimicrobial susceptibility, biofilm production, and clonal relatedness of vancomycin-resistant E. faecium (VREF) clinical isolates from two hospitals in Mexico. Consecutive clinical isolates (n=56) were collected in two tertiary care hospitals in Mexico from 2011 to 2014. VREF isolates were characterized by phenotypic and molecular methods including pulsed-field gel electrophoresis (PFGE). VREF isolates were highly resistant to vancomycin, erythromycin, norfloxacin, high-level streptomycin, and teicoplanin, and showed lower resistance to tetracycline, nitrofurantoin and quinupristin-dalfopristin. None of the isolates were resistant to linezolid. The vanA gene was detected in all isolates. Two VanB phenotype-vanA genotype isolates, highly resistant to vancomycin and susceptible to teicoplanin, were detected. Furthermore, 17.9% of the isolates were classified as biofilm producers, and the espfm gene was found in 98.2% of the isolates. A total of 37 distinct PFGE patterns and 6 clones (25% of the isolates as clone A, 5.4% as clone B, and 3.6% each as clone C, D, E, and F) were detected. Clone A was detected in 5 different wards of the same hospital during 14 months of surveillance. The high resistance to most antimicrobial agents and the moderate cross-transmission of VREF detected accentuates the need for continuous surveillance of E. faecium in the hospital setting. This is also the first reported incidence of the E. faecium VanB phenotype-vanA genotype in the Americas. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Observed Antagonistic Effect of Linezolid on Daptomycin or Vancomycin Activity against Biofilm-Forming Methicillin-Resistant Staphylococcus aureus in an In Vitro Pharmacodynamic Model

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Luther, Megan K.

2015-01-01

Pharmacodynamic activity in antibiotic combinations of daptomycin, vancomycin, and linezolid was investigated in a 48-h in vitro pharmacodynamic model. Using human-simulated free drug concentrations, activity against clinical biofilm-forming methicillin-resistant Staphylococcus aureus isolates was evaluated. Linezolid antagonized vancomycin activity at 24 and 48 h. Linezolid antagonized daptomycin at 24 and 48 h depending on dose and strain. Adding daptomycin increased vancomycin activity at 48 h (P < 0.03). These results may be strain dependent and require further clinical investigation. PMID:26369963

Vancomycin resistant Enterococcus spp. from crows and their environment in metropolitan Washington State, USA: Is there a correlation between VRE positive crows and the environment?

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Roberts, Marilyn C; No, David B; Marzluff, John M; Delap, Jack H; Turner, Robert

2016-10-15

Vancomycin-resistant enterococci [VRE] have been isolated from municipal, hospital and agricultural wastewater, recreational beaches, wild animals, birds and food animals around the world. In this study, American crows (Corvus brachyrhynchos) from sewage treatment plants (WWTP), dairy farms, and a large roost in a restored wetland with corresponding environmental samples were cultured for VRE. A total of 245 samples [156 crows, 89 environmental] were collected and screened for acquired vanA, vanB and/or intrinsic vanC1 genes. Samples were enriched overnight in BHI supplemented with 20μg/mL aztreonam, 4μg/mL vancomycin and plated on m-Enterococcus agar media supplemented with 6μg/mL vancomycin. Selected colonies were grown on BHI media supplemented with 18μg/mL vancomycin. Of these, 24.5% of the crow and 55% the environmental/cow samples were VRE positive as defined by Enterococcus spp. able to grow on media supplemented with 18μg/mL vancomycin. A total of 122 VRE isolates, 43 crow and 79 environmental isolates were screened, identified to species level using 16S sequencing and further characterized. Four vanA E. faecium and multiple vanC1 E. gallinarum were identified from crows isolated from three sites. E. faecium vanA and E. gallinarum vanC1 along with other Enterococcus spp. carrying vanA, vanB, vanC1 were isolated from three environments. All enterococci were multidrug resistant. Crows were more likely to carry vanA E. faecium than either the cow feces or wetland waters/soils. Comparing E. gallinarum vanC1 from crows and their environment would be useful in determining whether crows share VRE strains with their environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparative effectiveness of linezolid versus vancomycin as definitive antibiotic therapy for heterogeneously resistant vancomycin-intermediate coagulase-negative staphylococcal central-line-associated bloodstream infections in a neonatal intensive care unit.

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Blanchard, A C; Fortin, E; Laferrière, C; Goyer, I; Moussa, A; Autmizguine, J; Quach, C

2017-06-01

Heterogeneously resistant vancomycin-intermediate coagulase-negative staphylococci (hVICoNS) are emerging pathogens causing central-line-associated bloodstream infections (CLABSIs) in neonatal intensive care unit (NICU) patients. Given the burden of disease associated with CLABSI and the current lack of therapeutic guidelines, we aimed to compare the effectiveness of linezolid versus vancomycin used as the definitive antibiotic therapy for hVICoNS CLABSI. We performed a retrospective cohort study of infants with hVICoNS CLABSI from a single NICU between 2009 and 2014, treated with either linezolid or vancomycin as definitive antibiotic therapy. CLABSI duration, early and late recurrence and in-hospital mortality were compared using propensity score-adjusted proportional hazards and logistic regression models. Of 89 infants with hVICoNS CLABSI, 33 (37.1%) treated with linezolid were compared with 56 (62.9%) treated with vancomycin. The median duration of CLABSI was 5 (range 1-12) versus 4 days (range 0-14) ( P  =   0.11), early recurrences were 3.0% versus 7.1% ( P  =   0.42), late recurrences 0% versus 14.3% ( P  =   0.02) and mortality 27.3% versus 28.6% ( P  =   0.90), when treated with linezolid versus vancomycin, respectively. When adjusting using a continuous propensity score, linezolid had an HR of 0.78 (95% CI 0.48-1.27) for CLABSI duration, an OR of 0.23 (95% CI 0.02-2.56) for early recurrence and an OR of 0.9 (95% CI 0.3-2.67) for mortality, relative to vancomycin. There was no statistically significant difference between linezolid and vancomycin when used as definitive treatment for hVICoNS CLABSI in NICU patients, in terms of CLABSI duration, recurrence or all-cause mortality. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The cost effectiveness of vancomycin for preventing infections after shoulder arthroplasty: a break-even analysis.

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Hatch, M Daniel; Daniels, Stephen D; Glerum, Kimberly M; Higgins, Laurence D

2017-03-01

Increasing methicillin resistance and recognition of Propionibacterium acnes as a cause of infection in shoulder arthroplasty has led to the adoption of local vancomycin powder application as a more effective method to prevent expensive periprosthetic infections. However, no study has analyzed the cost effectiveness of vancomycin powder for preventing infection after shoulder replacement. Cost data for infection-related care of 16 patients treated for deep periprosthetic shoulder infection was collected from our institution for the break-even analysis. An equation was developed and applied to the data to determine how effective vancomycin powder would need to be at reducing a baseline infection rate to make prophylactic use cost effective. The efficacy of vancomycin (absolute risk reduction [ARR]) was evaluated at different unit costs, baseline infection rates, and average costs of treating infection. We determined vancomycin to be cost effective if the initial infection rate decreased by 0.04% (ARR). Using the current costs of vancomycin reported in the literature (range: $2.50/1000 mg to $44/1000 mg), we determined vancomycin to be cost effective with an ARR range of 0.01% at a cost of $2.50/1000 mg to 0.19% at $44/1000 mg. Baseline infection rate does not influence the ARR obtained at any specific cost of vancomycin or the cost of treating infection. We have derived and used a break-even equation to assess efficacy of prophylactic antibiotics during shoulder surgery. We further demonstrated the prophylactic administration of local vancomycin powder during shoulder arthroplasty to be a highly cost-effective practice. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Enviromnental contamination during a vancomycin-resistant Enterococci outbreak at a hospital in Argentina

OpenAIRE

Zarate, Mariela Soledad; Gales, Ana [UNIFESP; Jordd-Vargas, L'fiana; Yahni, Diego; RelloSo, Silvia; Bonvehi, Pablo; Monteiro, Jussimara [UNIFESP; Campos-Pignatari, Antonio [UNIFESP; Smayevsky, Jorgelina [UNIFESP

2007-01-01

INTRODUCTION. Vancomycin-resistant enterococci isolates (VRE) have caused numerous outbreaks in intensive care units (ICUs). A contaminated hospital environment, the hands of health care workers (HCW), and carrier patients may play important roles in perpetuating the chain of transmission in these outbreaks. the aims of this study were to report the first VRE outbreak in our center and assess the role of environmental contamination and HCW hands in the spread of new cases of enterococcal infe...

Analysis of the world epidemiological situation among vancomycin-resistant Enterococcus faecium infections and the current situation in Poland

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Talaga-Ćwiertnia, Katarzyna; Bulanda, Małgorzata

2018-01-01

Vancomycin-resistant Enterococcus faecium (VREfm) strains have become an important hospital pathogen due to their rapid spread, high mortality rate associated with infections and limited therapeutic options. Vancomycin resistance is predominantly mediated by VanA or VanB phenotypes, which differ as regards maintaining sensitivity to teicoplanin in the VanB phenotype. The majority of VREfm cases in the United States, Europe, Korea, South America and Africa are currently caused by the VanA phenotype. However, the epidemics in Australia and Singapore are chiefly brought about by the VanB phenotype. The rate of VREfm isolate spread varies greatly. The greatest percentage of VREfm is now recorded in the USA, Ireland and Australia. Supervision of VRE is implemented to varying degrees. Therefore, the epidemiological situation in some countries is difficult to assess due to limited data or lack thereof.

Study on the susceptibility of Enterococcus faecalis from infectious processes to ciprofloxacin and vancomycin

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A. Genaro

2005-09-01

Full Text Available Enterococcus faecalis is considered a pathogen responsible for hospital infections and, due to its frequent multi-resistant profile, has caused preoccupations among many medical authorities. The objective of this study was to determine the antimicrobial susceptibility of 74 strains isolated from blood cultures and purulent secretions to vancomycin and ciprofloxacin through the Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC by using the Microdilution test. The results showed a greater efficacy of vancomycin compared to ciprofloxacin (98.6% of the strains were inhibited by vancomycin at lower concentrations: 0.06 - 1 µg/ml. However, in the MBC analysis 73% of the strains showed a MBC of vancomycin only at high concentrations (equal to or higher than 64 µg/ml. For ciprofloxacin, the strains showed a broad sensitivity with MICs and MBCs distributed along all the MIC classes. Results also revealed a probability that some strains are tolerant to vancomycin, which indicates the need of other tests to confirm this characteristic.

Identification of putative drug targets in Vancomycin-resistant Staphylococcus aureus (VRSA) using computer aided protein data analysis.

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Hasan, Md Anayet; Khan, Md Arif; Sharmin, Tahmina; Hasan Mazumder, Md Habibul; Chowdhury, Afrin Sultana

2016-01-01

Vancomycin-resistant Staphylococcus aureus (VRSA) is a Gram-positive, facultative aerobic bacterium which is evolved from the extensive exposure of Vancomycin to Methicillin resistant S. aureus (MRSA) that had become the most common cause of hospital and community-acquired infections. Due to the emergence of different antibiotic resistance strains, there is an exigency to develop novel drug targets to address the provocation of multidrug-resistant bacteria. In this study, in-silico genome subtraction methodology was used to design potential and pathogen specific drug targets against VRSA. Our study divulged 1987 proteins from the proteome of 34,549 proteins, which have no homologues in human genome after sequential analysis through CD-HIT and BLASTp. The high stringency analysis of the remaining proteins against database of essential genes (DEG) resulted in 169 proteins which are essential for S. aureus. Metabolic pathway analysis of human host and pathogen by KAAS at the KEGG server sorted out 19 proteins involved in unique metabolic pathways. 26 human non-homologous membrane-bound essential proteins including 4 which were also involved in unique metabolic pathway were deduced through PSORTb, CELLO v.2.5, ngLOC. Functional classification of uncharacterized proteins through SVMprot derived 7 human non-homologous membrane-bound hypothetical essential proteins. Study of potential drug target against Drug Bank revealed pbpA-penicillin-binding protein 1 and hypothetical protein MQW_01796 as the best drug target candidate. 2D structure was predicted by PRED-TMBB, 3D structure and functional analysis was also performed. Protein-protein interaction network of potential drug target proteins was analyzed by using STRING. The identified drug targets are expected to have great potential for designing novel drugs against VRSA infections and further screening of the compounds against these new targets may result in the discovery of novel therapeutic compounds that can be

Tedizolid susceptibility in linezolid- and vancomycin-resistant Enterococcus faecium isolates.

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Klupp, E-M; Both, A; Belmar Campos, C; Büttner, H; König, C; Christopeit, M; Christner, M; Aepfelbacher, M; Rohde, H

2016-12-01

Vancomycin-resistant enterococci (VRE) are of ever-increasing importance, most notably in high-risk patient populations. Therapy options are often limited for these isolates, and apart from tigecycline and daptomycin, oxazolidinone linezolid is frequently administered. The broad usage of linezolid, however, has driven the emergence of linezolid-resistant VRE strains (LR-VRE), further shortening therapeutic options. Second-generation oxazolidinone tedizolid has the advantage of being active against a specific subset of LR-VRE, i.e. isolates expressing the plasmid-encoded chloramphenicol-florfenicol resistance (cfr) gene. Here we tested tedizolid activity in a collection of 30 LR Enterococcus faecium VRE (MIC range 32-256 mg/l) isolated between 2012 and 2015 from clinical and screening specimens. By pulsed field gel electrophoresis (PFGE) isolates were assigned to 16 clonal lineages. In three cases, linezolid-susceptible progenitor isolates of LR-VRE were isolated, thus demonstrating the de-novo emergence of the linezolid-resistant phenotype. PCR did not detect cfr, cfr(B) or novel oxazolidinone resistance gene optrA in LR-VRE. All isolates, however, carried mutations within the 23S rDNA. Compared to linezolid, tedizolid MICs were lower in all isolates (MIC range 2-32 mg/l), but remained above the FDA tedizolid breakpoint for E. faecalis at 0.5 mg/l. Thus, related to the predominant resistance mechanism, tedizolid is of limited value for treatment of most LR-VRE and represents a therapeutic option only for a limited subset of isolates.

Prevalence and Removal Efficiency of Enterococcal Species and Vancomycin-resistant Enterococci of a Hospital Wastewater Treatment Plant

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Fatemeh Karimi

2016-12-01

Full Text Available Simultaneous presence of various antibiotics and bacteria in hospital wastewaters creates a suitable environment, in which the bacteria, such as ‎enterococci become resistant to the antibiotics. The aim of this study was to evaluate the performance of different units of the hospital wastewater treatment plant (HWTP to remove Enterococcus spp and Vancomycin-resistant Enterococcus (VRE. The study was performed on the 27 samples collected from HWTP in Hamedan, Iran during December 2014 to August 2015. Enterococcus spp and VRE were identified by biochemical tests and then the isolates were confirmed by PCR. Finally, the antibiotic susceptibility test was performed using disk diffusion methods. Of the 27 samples examined, 315 a total of enterococcal isolates were obtained. Of the 315 isolates of enterococci investigated, 162 (51.42% were identified as E. faecium, 87 (27.61% as E. hirae, 35 (11.11% as E. faecalis, 11 (3.5% as E. gallinarum, 7 (2.22% as E. casseliflavus, 4 (1.26% E. avium, and 9 (2.85% isolates VR E. faecium.The results of antibiotic susceptibility testing showed that of the total 315 isolates, 146 (46.34% were resistance to tetracycline, 9 (2.85% were resistance to vancomycin and Teicoplanin. Lower antibiotic resistance was seen with Nitrofurantoin 2 (1.26%. This study indicates a high prevalence of multidrug resistance among E. faecium isolated from HWTP, thus, it could be considered as a threat to the health and safety of ‎wastewater workers and even public health.

Endophthalmitis caused by gram-positive bacteria resistant to vancomycin: Clinical settings, causative organisms, antimicrobial susceptibilities, and treatment outcomes

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Hegde Sharat Shivaramaiah

2018-06-01

Full Text Available Purpose: To report the clinical settings, causative organisms, antimicrobial susceptibilities, and treatment outcomes of patients with endophthalmitis caused by gram-positive bacteria resistant to vancomycin. Methods: Retrospective case series of all patients with culture-proven endophthalmitis caused by gram-positive bacteria resistant to vancomycin between January 2010 and December 2016 in LV Prasad Eye Institute, Visakhapatnam, India. Results: The current study included 14 patients. The clinical settings were post-cataract surgery in 8/14 (57.1% and open globe injury in 6/14 (42.8%. Primary intervention for all patients included tap and intravitreal antibiotic injection. During subsequent follow-up, pars plana vitrectomy was performed in 6 patients and one patient underwent penetrating keratoplasty. Mean number of intravitreal antibiotic injections performed were 3.4 per patient. The most common organisms isolated were coagulase-negative Staphylococci in 6/14 (42.8%, Staphylococcus aureus in 5/14 (35.7%, Streptococcus sp in 2/14 (14.2% and Bacillus sp in 1/14 (7.14%. In addition to vancomycin, resistance to multiple drugs (three or more groups of antibiotics was found in all 14 cases. Antimicrobial susceptibility results showed susceptibility to amikacin in 7/14 (50.0%, gatifloxacin in 6/14 (42.8%, moxifloxacin in 3/13 (23.0%, cefazoline in 5/14 (35.7%, cefuroxime in 3/14 (21.4%, ciprofloxacin in 2/14 (14.2% and linezolid in 5/5 (100%. The mean duration of follow-up was 30.7 weeks (6 weeks–90 weeks. At last follow-up, visual acuity (VA of 20/200 or better was recorded in 7/14 (50% and VA < 5/200 occurred in 7/14 (50%. Conclusion and importance: Antimicrobial susceptibility testing may help in selection of suitable antimicrobial agents for repeat intravitreal injection. Inspite of retreatment with intravitreal antibiotics, these patients generally had poor VA outcomes. Keywords: Coagulase-negative Staphylococci, Endophthalmitis

Intestinal Microbiota Containing Barnesiella Species Cures Vancomycin-Resistant Enterococcus faecium Colonization

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Bucci, Vanni; Caballero, Silvia; Djukovic, Ana; Toussaint, Nora C.; Equinda, Michele; Lipuma, Lauren; Ling, Lilan; Gobourne, Asia; No, Daniel; Taur, Ying; Jenq, Robert R.; van den Brink, Marcel R. M.; Xavier, Joao B.

2013-01-01

Bacteria causing infections in hospitalized patients are increasingly antibiotic resistant. Classical infection control practices are only partially effective at preventing spread of antibiotic-resistant bacteria within hospitals. Because the density of intestinal colonization by the highly antibiotic-resistant bacterium vancomycin-resistant Enterococcus (VRE) can exceed 109 organisms per gram of feces, even optimally implemented hygiene protocols often fail. Decreasing the density of intestinal colonization, therefore, represents an important approach to limit VRE transmission. We demonstrate that reintroduction of a diverse intestinal microbiota to densely VRE-colonized mice eliminates VRE from the intestinal tract. While oxygen-tolerant members of the microbiota are ineffective at eliminating VRE, administration of obligate anaerobic commensal bacteria to mice results in a billionfold reduction in the density of intestinal VRE colonization. 16S rRNA gene sequence analysis of intestinal bacterial populations isolated from mice that cleared VRE following microbiota reconstitution revealed that recolonization with a microbiota that contains Barnesiella correlates with VRE elimination. Characterization of the fecal microbiota of patients undergoing allogeneic hematopoietic stem cell transplantation demonstrated that intestinal colonization with Barnesiella confers resistance to intestinal domination and bloodstream infection with VRE. Our studies indicate that obligate anaerobic bacteria belonging to the Barnesiella genus enable clearance of intestinal VRE colonization and may provide novel approaches to prevent the spread of highly antibiotic-resistant bacteria. PMID:23319552

AUC-Guided Vancomycin Dosing in Adolescent Patients With Suspected Sepsis.

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Lanke, Shankar; Yu, Tian; Rower, Joseph E; Balch, Alfred H; Korgenski, E Kent; Sherwin, Catherine M

2017-01-01

Vancomycin is a first-line treatment for β-lactam-resistant Gram-positive bacterial infections. Understanding the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of vancomycin in an adolescent population is of clinical importance in this often overlooked pediatric population. This retrospective study investigated vancomycin PK-PD in an adolescent cohort (12 to 18 years of age) of 463 patients (57% male, 81% white) admitted to the Intermountain Healthcare System between January 2006 and December 2013. Population PK modeling was performed in NONMEM 7.3. Vancomycin PK was well described with a 1-compartment model that identified both body weight (WT) and creatinine clearance (CRCL) as covariates significantly impacting vancomycin disposition. The model was then utilized to determine dosing strategies that achieved the targeted area under the 24-hour time curve vs minimum inhibitory concentration (AUC 0-24 /MIC) ratio of ≥400. Additionally, these data were correlated with minimum steady-state concentrations (C ss,min ) to find an acceptable target trough concentration range in adolescents. This analysis demonstrated that C ss,min ranging from 10 to 12.5 mg/L were highly predictive of achieving an AUC 0-24 /MIC ≥400 when the MIC was ≤1 mg/L. These results suggest that the target trough concentration for adolescents may be lower than that for adults. © 2016, The American College of Clinical Pharmacology.

Leuconostoc garlicum: an unusual pathogen in the era of vancomycin therapy.

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Kumar, Anil; Augustine, Deepthi; Mehta, Asmita; Dinesh, Kavitha R; Viswam, Darsana; Philip, Rosamma

2012-01-01

Leuconostoc garlicum, belonging to the family of Leuconostocaceae, is a catalase-negative, Gram-positive ovoid cocci, intrinsically resistant to vancomycin. Clinical infection by Leuconostoc garlicum is rare. We report a case of respiratory tract infection subsequent to vancomycin therapy.

Controlled Delivery of Vancomycin via Charged Hydrogels.

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Carl T Gustafson

Full Text Available Surgical site infection (SSI remains a significant risk for any clean orthopedic surgical procedure. Complications resulting from an SSI often require a second surgery and lengthen patient recovery time. The efficacy of antimicrobial agents delivered to combat SSI is diminished by systemic toxicity, bacterial resistance, and patient compliance to dosing schedules. We submit that development of localized, controlled release formulations for antimicrobial compounds would improve the effectiveness of prophylactic surgical wound antibiotic treatment while decreasing systemic side effects. Our research group developed and characterized oligo(poly(ethylene glycolfumarate/sodium methacrylate (OPF/SMA charged copolymers as biocompatible hydrogel matrices. Here, we report the engineering of this copolymer for use as an antibiotic delivery vehicle in surgical applications. We demonstrate that these hydrogels can be efficiently loaded with vancomycin (over 500 μg drug per mg hydrogel and this loading mechanism is both time- and charge-dependent. Vancomycin release kinetics are shown to be dependent on copolymer negative charge. In the first 6 hours, we achieved as low as 33.7% release. In the first 24 hours, under 80% of total loaded drug was released. Further, vancomycin release from this system can be extended past four days. Finally, we show that the antimicrobial activity of released vancomycin is equivalent to stock vancomycin in inhibiting the growth of colonies of a clinically derived strain of methicillin-resistant Staphylococcus aureus. In summary, our work demonstrates that OPF/SMA hydrogels are appropriate candidates to deliver local antibiotic therapy for prophylaxis of surgical site infection.

Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

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Raghabendra Adhikari

2017-01-01

Full Text Available The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA, taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47% S. aureus isolates were recovered, of which 39 (35.50% isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%, both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

Comparative Effectiveness of Vancomycin Versus Daptomycin for MRSA Bacteremia With Vancomycin MIC >1 mg/L: A Multicenter Evaluation.

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Moise, Pamela A; Culshaw, Darren L; Wong-Beringer, Annie; Bensman, Joyce; Lamp, Kenneth C; Smith, Winter J; Bauer, Karri; Goff, Debra A; Adamson, Robert; Leuthner, Kimberly; Virata, Michael D; McKinnell, James A; Chaudhry, Saira B; Eskandarian, Romic; Lodise, Thomas; Reyes, Katherine; Zervos, Marcus J

2016-01-01

Clinical studies comparing vancomycin with alternative therapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia are limited. The objective of this study was to compare outcomes of early daptomycin versus vancomycin treatment for MRSA bacteremia with high vancomycin MICs in a geographically diverse multicenter evaluation. This nationwide, retrospective, multicenter (N = 11), matched, cohort study compared outcomes of early daptomycin with vancomycin for MRSA bloodstream infection (BSI) with vancomycin MICs 1.5 to 2 µg/mL. Matching variables, based on propensity regression analysis, included age, intensive care unit (ICU), and type of BSI. Outcomes were as follows: (1) composite failure (60-day all-cause mortality, 7-day clinical or microbiologic failure, 30-day BSI relapse, or end-of-treatment failure (EOT; discontinue/change daptomycin or vancomycin because of treatment failure or adverse event]); (2) nephrotoxicity; and (2) day 4 BSI clearance. A total of 170 patients were included. The median (interquartile range) age was 60 years (50-74); the median (range) Acute Physiology and Chronic Health Evaluation II score was 15 (10-18); 31% were in an ICU; and 92% had an infectious disease consultation. BSI types included endocarditis/endovascular (39%), extravascular (55%), and central catheter (6%). The median daptomycin dose was 6 mg/kg, and the vancomycin trough level was 17 mg/L. Overall composite failure was 35% (59 of 170): 15% due to 60-day all-cause mortality, 14% for lack of clinical or microbiologic response by 7 days, and 17% due to failure at end of therapy (discontinue/change because of treatment failure or adverse event). Predictors of composite failure according to multivariate analysis were age >60 years (odds ratio, 3.7; P day 4 bacteremia clearance rates for immunocompromised patients (n = 26) (94% vs 56% for daptomycin vs vancomycin; P = 0.035). Results from this multicenter study provide, for the first time, a geographically diverse

Annual Surveillance Summary: Vancomycin-Resistant Enterococci (VRE) Infections in the Military Health System (MHS), 2016

Science.gov (United States)

2017-06-01

policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government . i i VRE in the MHS: Annual Summary 2016 Prepared...continually increased from 1.16 infections per 100,000 persons in 2013 to 1.60 infections per 100,000 persons in 2015. A recent meta -analysis of VRE...associated with infections caused by vancomycin-resistant enterococci in the United States: systematic literature review and meta -analysis. Infect

Outbreak of vancomycin-resistant Enterococcus faecium in a haematology unit: risk factor assessment and successful control of the epidemic

NARCIS (Netherlands)

Timmers, Gert Jan; van der Zwet, Wil C.; Simoons-Smit, Ina M.; Savelkoul, Paul H. M.; Meester, Helena H. M.; Vandenbroucke-Grauls, Christina M. J. E.; Huijgens, Peter C.

2002-01-01

We describe an outbreak of vancomycin-resistant Enterococcus faecium (VRE) on the haematology ward of a Dutch university hospital. After the occurrence of three consecutive cases of bacteraemia with VRE, strains were genotyped and found to be identical. During the next 4 months an intensive

Association between Vancomycin Day 1 Exposure Profile and Outcomes among Patients with Methicillin-Resistant Staphylococcus aureus Infective Endocarditis

Science.gov (United States)

Casapao, Anthony M.; Lodise, Thomas P.; Davis, Susan L.; Claeys, Kimberly C.; Kullar, Ravina; Levine, Donald P.

2015-01-01

Given the critical importance of early appropriate therapy, a retrospective cohort (2002 to 2013) was performed at the Detroit Medical Center to evaluate the association between the day 1 vancomycin exposure profile and outcomes among patients with MRSA infective endocarditis (IE). The day 1 vancomycin area under the concentration-time curve (AUC0–24) and the minimum concentration at 24 h (Cmin 24) was estimated for each patient using the Bayesian procedure in ADAPT 5, an approach shown to accurately predict the vancomycin exposure with low bias and high precision with limited pharmacokinetic sampling. Initial MRSA isolates were collected and vancomycin MIC was determined by broth microdilution (BMD) and Etest. The primary outcome was failure, defined as persistent bacteremia (≥7 days) or 30-day attributable mortality. Classification and regression tree analysis (CART) was used to determine the vancomycin exposure variables associated with an increased probability of failure. In total, 139 patients met study criteria; 76.3% had right-sided IE, 16.5% had left-sided IE, and 7.2% had both left and right-sided IE. A total of 89/139 (64%) experienced failure by composite definition. In the CART analysis, failure was more pronounced in patients with an AUC0–24/MIC as determined by BMD of ≤600 relative to those with AUC0–24/MIC as determined by BMD of >600 (69.8% versus 54.7%, respectively, P = 0.073). In the logistic regression analysis, an AUC/MIC as determined by BMD of ≤600 (adjusted odds ratio, 2.3; 95% confidence interval, 1.01 to 5.37; P = 0.047) was independently associated with failure. Given the retrospective nature of the present study, further prospective studies are required but these data suggest that patients with an AUC0–24/MIC as determined by BMD of ≤600 present an increased risk of failure. PMID:25753631

Frecuencia de aislamiento de Staphylococcus spp meticilina resistentes y Enterococcus spp vancomicina resistentes en hospitales de Cuba Frequency of methicilline-resistant Staphylococcus spp and vancomycin-resistant Enterococcus spp isolates in Cuban hospitals

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Leonora González Mesa

2005-12-01

Full Text Available La resistencia a meticilina en el género Staphylococcus spp es un problema creciente en el ámbito mundial. La producción de una PBP alterada (PBP2a con baja afinidad a betalactámicos, mediada por el gen mec A, es la responsable de esta resistencia. Mientras que los Staphylococcus spp todavía permanecen sensibles a vancomicina, algunos Enterococcus spp han adquirido la capacidad de neutralizar esta droga. En nuestro país no se conocen datos actualizados sobre la tasa de infección por S. aureus meticilina resistente (SAMR, ni sobre la circulación de este germen en la comunidad, tampoco existen reportes de Enterococcus spp vancomicina resistente (EVR. En este estudio fueron analizadas 774 cepas, colectadas en hospitales del país. Se determinó el mecanismo de resistencia utilizando métodos sugeridos por las guías NCCLS. El 9.3 % (23 de los S. aureus aislados en los hospitales y 4.0% (7 S. aureus aislados en la comunidad, fueron SAMR, portadores del gen mec A, el 69.9 % (72 de Staphylococcus coagulasa negativo, fueron resistentes a oxacilina. En la detección del Enterococcus spp vancomicina resistente (EVR, se encontró una cepa portadora de este fenotipo. Nuestros resultados revelan que en nuestro país los SAMR no son un problema en los hospitales, ni en el ambiente comunitario, a pesar de que se reporta por primera vez la circulación de estos en la comunidad y la circulación de EVR en el ambiente hospitalario, su frecuencia es muy baja lo que refleja los avances obtenidos en la aplicación de políticas encaminadas a racionalizar el uso y consumo de antibióticos.Resistance to methicilline in Staphylococcus spp genus is a growing problem worldwide. The production of an altered penicillin-fixing protein with low mecA gen-mediated affinity to beta-lactams is responsible for this resistance. Although Staphylococcus spp still remain susceptible to vancomycin, some Enterococcus spp have acquired the capacity of neutralizing this drug. In

Vancomycin gene selection in the microbiome of urban Rattus norvegicus from hospital environment

DEFF Research Database (Denmark)

Arn Hansen, Thomas; Joshi, Tejal; Larsen, Anders Rhod

2016-01-01

for the presence of antibiotic resistance genes. We show that despite the shared resistome within samples from the same geographic locations, samples from hospital area carry significantly abundant vancomycin resistance genes. The observed pattern is consistent with a selection for vancomycin genes in the R...

Evaluation of vancomycin therapy in the adult ICUs of a teaching hospital in southern Iran

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Vazin A

2018-04-01

Full Text Available Afsaneh Vazin, Motahare Mahi Birjand, Masoud Darake Department of Clinical Pharmacy, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran Background: Vancomycin resistance in intensive care units (ICUs accounts for significant morbidity and excess costs. The objective of the present study was to determine the appropriateness of vancomycin use in the various ICUs of Nemazee Hospital, Shiraz, Iran. Methods: This prospective study was performed on 95 critically ill patients (48 males and 47 females who were treated with vancomycin for at least 3 subsequent doses in 6 ICUs during 12 months. Required demographic, clinical, and paraclinical data were collected by a pharmacist. Fifteen indexes were considered for evaluation of vancomycin use. Results: Ventilator-associated hospital-acquired pneumonia (22.6%, sepsis (22.1% and CNS infection (12.6% were found to be the most important indications for vancomycin prescription. Vancomycin was prescribed empirically in 81% of patients. None of the patients received loading dose, and most of the patients received fixed dose. The rate of prolonged empiric antibiotic therapy was 68.5% in patients who received vancomycin. The mean score of vancomycin use in the ICUs of Nemazee Hospital was 7.1±0.6 out of 15, implying that the rate of vancomycin use was in accordance with the guideline proposed by the Department of Clinical Pharmacy of Nemazee Hospital based on Infectious Diseases Society of America by 47.3%. Conclusion: Based on our results, the weakness in using vancomycin was related to not administering loading dose, the practice of prescribing fixed-dose vancomycin and prolonged duration of empiric therapy. Efforts to improve the pattern of vancomycin prescription and utilization in these ICUs should be undertaken. Keywords: vancomycin, drug utilization, intensive care units

Occurrence of airborne vancomycin- and gentamicin-resistant bacteria in various hospital wards in Isfahan, Iran.

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Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmad, Hossein; Hassanzadeh, Akbar

2016-01-01

Airborne transmission of pathogenic resistant bacteria is well recognized as an important route for the acquisition of a wide range of nosocomial infections in hospitals. The aim of this study was to determine the prevalence of airborne vancomycin and gentamicin (VM and GM) resistant bacteria in different wards of four educational hospitals. A total of 64 air samples were collected from operating theater (OT), Intensive Care Unit (ICU), surgery ward, and internal medicine ward of four educational hospitals in Isfahan, Iran. Airborne culturable bacteria were collected using all glass impingers. Samples were analyzed for the detection of VM- and GM-resistant bacteria. The average level of bacteria ranged from 99 to 1079 CFU/m(3). The highest level of airborne bacteria was observed in hospital 4 (628 CFU/m(3)) and the highest average concentration of GM- and VM-resistant airborne bacteria were found in hospital 3 (22 CFU/m(3)). The mean concentration of airborne bacteria was the lowest in OT wards and GM- and VM-resistant airborne bacteria were not detected in this ward of hospitals. The highest prevalence of antibiotic-resistant airborne bacteria was observed in ICU ward. There was a statistically significant difference for the prevalence of VM-resistant bacteria between hospital wards (P = 0.012). Our finding showed that the relatively high prevalence of VM- and GM-resistant airborne bacteria in ICUs could be a great concern from the point of view of patients' health. These results confirm the necessity of application of effective control measures which significantly decrease the exposure of high-risk patients to potentially airborne nosocomial infections.

[Microbiological and epidemiological characteristics of vancomycin-dependent enterococci].

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Hwang, Keumrock; Sung, Heungsup; Namgoong, Seung; Yoon, Nam Surp; Kim, Mi-Na

2009-08-01

Vancomycin-dependent enterococci (VDE) are clinically equivalent to vancomycin-resistant enterococci (VRE), but more difficult to detect. This study was purposed to characterize VDE microbiologically and epidemiologically. The patients from whom VDE were detected from April 2007 to March 2008 were investigated. For available isolates, minimal inhibitory concentrations (MICs) of and the levels of dependence on vancomycin and teicoplanin were measured by E test (AB Biodisk, Sweden), and a test for reversion of VDE to non-dependent VRE (NDVRE) and pulsed field gel electrophoresis (PFGE) were performed. Patients' demographic and clinical findings were reviewed via electronic medical records. VDE were recovered from 6 (2.2%) of 272 patients carrying VRE during this study period. All patients were already colonized or infected by VRE and treated with vancomycin for 13 to 107 days. VDE were isolated from pleural fluid (one), urine (four), and stool (one). All isolates carried vanA with vancomycin MICs of >256 microg/mL, but two of them had intermediate susceptibilities to teicoplanin. Because 4 VDE isolates were reverted to NDVRE with single passage, vancomycin dependence was measurable for only two isolates as equal and above 0.064 and 0.5 microg/mL respectively, and was reverted after 5 and 7 passages, respectively. Six VDE isolates showed no related clones in PFGE analysis, and 3 of 4 available pairs of initial VRE isolates and subsequent VDE isolates were identical clones. VDE were not rare and seemed to emerge independently from VRE with a prolonged use of vancomycin. Vancomycin-dependence was reverted within several passages.

An Outbreak of Vancomycin-Resistant Enterococcus faecium in an Acute Care Pediatric Hospital: Lessons from Environmental Screening and a Case-Control Study

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Steven J Drews

2008-01-01

Full Text Available BACKGROUND: The present study describes a vancomycin-resistant enterococci (VRE outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital.

Efficacy of linezolid, teicoplanin, and vancomycin in prevention of an experimental polytetrafluoroethylene graft infection model caused by methicillin-resistant Staphylococcus aureus.

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Mese, Bulent; Bozoglan, Orhan; Elveren, Serdal; Eroglu, Erdinc; Gul, Mustafa; Celik, Ahmet; Ciralik, Harun; Yildirimdemir, Halil Ibrahim; Yasim, Alptekin

2015-03-27

The aim of this study was to evaluate the effectiveness of linezolid, teicoplanin, and vancomycin in prevention of prosthetic vascular graft infections in a vascular graft infection model. Fifty rats were divided into 5 groups. A polytetrafluoroethylene graft was implanted on the back of each rat. Methicillin-resistant Staphylococcus aureus (MRSA) strain was inoculated into all rats except Group 1. Group 2 was not given any treatment, Group 3 received linezolid, Group 4 received vancomycin, and Group 5 received teicoplanin. The grafts were removed for microbiological and histological examinations on the 7th day. In addition, C-reactive protein and prealbumin levels and leukocyte counts in obtained blood specimens were determined. Group 1 did not have infection. Group 2 had bacteria 5.7 × 10(4) CFU/cm(2). Group 3 and Group 4 had less bacterial growth. Group 5 had no bacterial growth. The number of bacteria was significantly higher in Group 2 than in the other experimental groups and the control group (pprevention of prosthetic vascular graft infections.

Optimization of a Laboratory-Developed Test Utilizing Roche Analyte-Specific Reagents for Detection of Staphylococcus aureus, Methicillin-Resistant S. aureus, and Vancomycin-Resistant Enterococcus Species▿

OpenAIRE

Mehta, Maitry S.; Paule, Suzanne M.; Hacek, Donna M.; Thomson, Richard B.; Kaul, Karen L.; Peterson, Lance R.

2008-01-01

Nasal and perianal swab specimens were tested for detection of Staphylococcus aureus and vancomycin-resistant Enterococcus species (VRE) using a laboratory-developed real-time PCR test and microbiological cultures. The real-time PCR and culture results for S. aureus were similar. PCR had adequate sensitivity, but culture was more specific for the detection of VRE.

Activity of vancomycin, linezolid, and daptomycin against staphylococci and enterococci isolated in 5 Greek hospitals during a 5-year period (2008-2012).

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Papadimitriou-Olivgeris, Matthaios; Kolonitsiou, Fevronia; Zerva, Loukia; Lebessi, Evangelia; Koutsia, Chryssa; Drougka, Eleanna; Sarrou, Styliani; Giormezis, Nikolaos; Vourli, Sofia; Doudoulakakis, Anastassios; Konsolakis, Christos; Marangos, Markos; Anastassiou, Evangelos D; Petinaki, Efthimia; Spiliopoulou, Iris

2015-12-01

The tendency of vancomycin, linezolid, and daptomycin MICs was investigated among 6920 staphylococci and enterococci during a 5-year period. Antimicrobial consumption was determined. Decrease of vancomycin MIC was detected associated with reduction in consumption. Linezolid and daptomycin remained active. An upward trend of linezolid MIC for methicillin-resistant staphylococci was observed. Copyright © 2015 Elsevier Inc. All rights reserved.

An investigation of vancomycin minimum inhibitory concentration creep among methicillin-resistant Staphylococcus aureus strains isolated from pediatric patients and healthy children in Northern Taiwan.

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Chang, Chia-Ning; Lo, Wen-Tsung; Chan, Ming-Chin; Yu, Ching-Mei; Wang, Chih-Chien

2017-06-01

The phenomenon of vancomycin minimum inhibitory concentration (MIC) creep is an increasingly serious problem in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. In this study, we investigated the vancomycin and daptomycin MIC values of MRSA strains isolated from pediatric patients and MRSA colonized healthy children. Then, we assessed whether there was evidence of clonal dissemination for strains with an MIC to vancomycin of ≥ 1.5 μg/mL. We collected clinical MRSA isolates from pediatric patients and from healthy children colonized with MRSA during 2008-2012 at a tertiary medical center in northern Taiwan and obtained vancomycin and daptomycin MIC values using the Etest method. Pulse-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome (SCCmec) typing were used to assess clonal dissemination for strains with an MIC to vancomycin of ≥ 1.5 μg/mL. A total 195 MRSA strains were included in this study; 87 were isolated patients with a clinical MRSA infection, and the other 108 strains from nasally colonized healthy children. Vancomycin MIC≥1.5 μg/mL was seen in more clinical isolates (60/87, 69%) than colonized isolates (32/108, 29.6%), p < 0.001. The PFGE typing of both strains revealed multiple pulsotypes. Vancomycin MIC creeps existed in both clinical MRSA isolates and colonized MRSA strains. Great diversity of PFGE typing was in both strains collected. There was no association between the clinical and colonized MRSA isolates with vancomycin MIC creep. Copyright © 2016. Published by Elsevier B.V.

Comparison of Linezolid and Vancomycin for Methicillin-Resistant Staphylococcus aureus Pneumonia: Institutional Implications.

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Tong, ManShan C; Wisniewski, Christopher S; Wolf, Bethany; Bosso, John A

2016-07-01

Recent studies suggesting clinical superiority of linezolid over vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia led to a change in our institution's clinical pathway/order form for hospital-acquired pneumonia, positioning linezolid as the preferred agent. Our objective was to assess the impact of this change within our institution. Retrospective electronic medical records review. The analysis for this observational study included eligible patients admitted to our medical center between May 1, 2011, and August 31, 2014, with ICD-9 codes for MRSA and pneumonia. Included patients were at least 18 years of age and had vancomycin or linezolid initiated at least 2 days after admission and continued for at least 2 consecutive days. The primary end points were extent of antibiotic use before and after order form change and length of stay (LOS) and hospital charges in the two treatment groups. A secondary aim was to detect any gross discrepancies in patient outcomes such as treatment duration, mechanical ventilation duration, all-cause mortality rate, nephrotoxicity, and 30-day readmission between the two treatment groups. Outcomes in 227 patients were assessed. Linezolid use increased 16.2% subsequent to the change in the order form. Although not statistically significant, the median hospital admission charge was $6200 lower in patients treated with linezolid compared with those treated with vancomycin ($25,900 vs $32,100). Hospital LOS was significantly associated with Charlson Comorbidity Index score (plinezolid treatment, and these patients were more likely to be discharged (shorter LOS). Although linezolid use increased markedly with this pathway/order form change, no negative institutional consequences or unfavorable patient outcomes were detected, justifying the change in policy from these perspectives. © 2016 Pharmacotherapy Publications, Inc.

Persistence of Vancomycin Resistance in Multiple Clones of Enterococcus faecium Isolated from Danish Broilers 15 Years after the Ban of Avoparcin

DEFF Research Database (Denmark)

Bortolaia, Valeria; Mander, Manuela; Jensen, Lars Bogø

2015-01-01

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....

Modeling the economic impact of linezolid versus vancomycin in confirmed nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus.

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Patel, Dipen A; Shorr, Andrew F; Chastre, Jean; Niederman, Michael; Simor, Andrew; Stephens, Jennifer M; Charbonneau, Claudie; Gao, Xin; Nathwani, Dilip

2014-07-22

We compared the economic impacts of linezolid and vancomycin for the treatment of hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA)-confirmed nosocomial pneumonia. We used a 4-week decision tree model incorporating published data and expert opinion on clinical parameters, resource use and costs (in 2012 US dollars), such as efficacy, mortality, serious adverse events, treatment duration and length of hospital stay. The results presented are from a US payer perspective. The base case first-line treatment duration for patients with MRSA-confirmed nosocomial pneumonia was 10 days. Clinical treatment success (used for the cost-effectiveness ratio) and failure due to lack of efficacy, serious adverse events or mortality were possible clinical outcomes that could impact costs. Cost of treatment and incremental cost-effectiveness per successfully treated patient were calculated for linezolid versus vancomycin. Univariate (one-way) and probabilistic sensitivity analyses were conducted. The model allowed us to calculate the total base case inpatient costs as $46,168 (linezolid) and $46,992 (vancomycin). The incremental cost-effectiveness ratio favored linezolid (versus vancomycin), with lower costs ($824 less) and greater efficacy (+2.7% absolute difference in the proportion of patients successfully treated for MRSA nosocomial pneumonia). Approximately 80% of the total treatment costs were attributed to hospital stay (primarily in the intensive care unit). The results of our probabilistic sensitivity analysis indicated that linezolid is the cost-effective alternative under varying willingness to pay thresholds. These model results show that linezolid has a favorable incremental cost-effectiveness ratio compared to vancomycin for MRSA-confirmed nosocomial pneumonia, largely attributable to the higher clinical trial response rate of patients treated with linezolid. The higher drug acquisition cost of linezolid was offset by lower treatment failure

Antibiotics in animal feed and their role in resistance development

DEFF Research Database (Denmark)

Wegener, Henrik Caspar

2003-01-01

Animals and humans constitute overlapping reservoirs of resistance, and consequently use of antimicrobials in animals can impact on public health. For example, the occurrence of vancomycin-resistant enterococci in food-animals is associated with the use of avoparcin, a glycopeptide antibiotic used...... as a feed additive for the growth promotion of animals. Vancomycin-resistant enterococci and vancomycin resistance determinants can therefore spread from animals to humans. The bans on avoparcin and other antibiotics as growth promoters in the EU have provided scientists with a unique opportunity......, the effects on animal health and productivity have been very minor....

Prevalence of methicillin-resistant staphylococci isolated from different biological samples at Policlinico Umberto I of Rome: correlation with vancomycin susceptibility

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Maria Teresa Mascellino

2011-03-01

Full Text Available The methicillin-resistance is increasing all over the world in the last decade. It is more frequent among coagulase-negative staphylococci (MRCoNS; infact the 52% of S. epidermidis strains results to be resistant to methicillin.The methicillin-resistant strains also show a reduced sensitivity towards the first-line agents such as glycopeptides and other antibiotics commonly used in therapy such as trimethoprim-sulphamethoxazole, imipenem, gentamycin, fosfomycin and chlarytromicin. Unlike MRSA (Methicillin-resistant S. aureus, MRCoNS resistance to glycopeptides generally concerns teicoplanin. Although vancomycin resistance is rare in Staphylococcus isolates, the detected shift towards higher values of MICs might affect patient’s clinical outcome.

CLINICAL ISOLATES OF MECA, METHICILLIN, VANCOMYCIN RESISTANCE S. AUREUS; ESBLs PRODUCING K.PNEUMONIA, E.COLI, P. AUREGENOSA FROM VARIOUS CLINICAL SOURCE AND ITS ANTIMICROBIAL RESISTANCE PATTERNS

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Ismail Mahmud Ali, Amirthalingam R

2015-01-01

Full Text Available Background and Objective: Antimicrobial resistance has turned into a key medical and public health crisis globally since the injudicious use of magic bullets (drugs. Aim of this study is focused on the clinical isolate and their percentages of resistant to antibiotics in gram positive bacteria such as MRSA, VRSA, and MSSA are common causes of nosocomical, skin structure infections, bacteremia and infection of other systems; ESBLs producing Enterobacteriaceae (E. coli, Klebsiella spp. is common agent of urinary tract, bloodstream, pulmonary and intra-abdominal infections and carbapenem resistant P. aeruginosa with its complete antimicrobial patterns which are currently practiced in this population. Methods: There are one hundred and fourteen (114 various clinical isolates, isolated from various clinical samples like throat swab, urine, pus, sputum, and blood culture, identified as specific isolate with resistance patterns were analyzed by BD phoenix-100 the auto analyzer. Results: Off 114 clinical isolate, 6 mecA-mediated resistance (cefoxitin>8mgc/ml, 11 methicillin resistance, 18 β lactam/βlactamase inhibitor, 12 methicillin sensitive and 3 vancomycin (>16µg/ml resistance S. aureus have been isolated from overall 50 isolate of S.aureus. In addition, there are 27 P.aeruginosa, 15 ESBLs from overall of 25 K. pneumoniae and 7 ESBLs out of 12 Escherichia coli species have been isolated. The resistance and susceptibility pattern percentages have been graphically represented for each isolates. Conclusion: Current study revealed that the drug classes of β lactam/βlactamase inhibitor having high resistance rate with S.aureus, P.aureginosa, K. pneumoniae and E. coli isolate. Also, some of other drug classes such as cepham and tetracycline having higher resistance rate with P.aureginosa and K.pneumoniae. In addition, the vancomycin resistances S. aureus have been isolated and reported as first time in this population.

Beta-Lactams combinations with Vancomycin provide synergy against VSSA, hVISA, and VISA.

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Tran, Kieu-Nhi; Rybak, Michael J

2018-03-19

Background: Increasing utilization of vancomycin due to the high prevalence of methicillin-resistant S. aureus (MRSA) infections has lead to the emergence of vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA). In vitro data suggest the potential for potent synergy between several beta-lactams and vancomycin. The objective of this study is to evaluate the synergy between beta-lactams and vancomycin against MRSA that is vancomycin susceptible, vancomycin susceptible Staphylococcus aureus (VSSA), hVISA, and VISA. Methods: Fifty randomly selected clinical MRSA strains with varying susceptibility to vancomycin were evaluated for vancomycin alone and vancomycin in combination with varying concentrations of cefazolin (CFZ), cefepime (FEP), ceftaroline (CPT), and nafcillin (NAF) minimum inhibitory concentration (MIC). The potential for synergy was assessed by 24h time-kills. Results: Beta-lactams reduced vancomycin MIC values against all strains (4-16 fold reduction). In time-kill studies against MRSA, CFZ, FEP, CPT, and NAF all demonstrated a similar extent of killing at 24h, and all showed synergistic activity with vancomycin against VSSA, hVISA, and VISA. Each of these combinations was also superior to any single agent against isolates of all three phenotypes, and each was bactericidal (P synergy of vancomycin against these Staphylococcus strains. Copyright © 2018 American Society for Microbiology.

Epidemiology of Extended-Spectrum beta-Lactamase-Producing E-coli and Vancomycin-Resistant Enterococci in the Northern Dutch-German Cross-Border Region

NARCIS (Netherlands)

Zhou, Xuewei; Garcia-Cobos, Silvia; Ruijs, Gijs J. H. M.; Kampinga, Greetje A.; Arends, Jan P.; Borst, Dirk M.; Moller, Lieke V.; Holman, Nicole D.; Schuurs, Theo A.; van Coppenraet, Lesla E. Bruijnesteijn; Weel, Jan F.; van Zeijl, Jan H.; Koeck, Robin; Rossen, John W. A.; Friedrich, Alexander W.

2017-01-01

Objectives: To reveal the prevalence and epidemiology of extended-spectrum β-lactamase (ESBL)- and/or plasmid AmpC (pAmpC)- and carbapenemase (CP) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) across the Northern Dutch-German border region. Methods: A point-prevalence study

Screening municipal wastewater effluent and surface water used for drinking water production for the presence of ampicillin and vancomycin resistant enterococci

NARCIS (Netherlands)

Taucer-Kapteijn, M.; Hoogenboezem, Wim; Heiliegers, Laura; de Bolster, Danny; Medema, G.

2016-01-01

The emergence of clinical enterococcal isolates that are resistant to both ampicillin and vancomycin is a cause of great concern, as therapeutic alternatives for the treatment of infections caused by such organisms are becoming limited. Aquatic environments could play a role in the dissemination

Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

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Vindel Ana

2011-04-01

Full Text Available Abstract Background Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. Case Presentation We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2 was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1 was fully vancomycin susceptible (VSSA. Although MRSA SaB2 was vancomycin susceptible (≤2 μg/ml by MIC (agar and broth dilution, E-test and VITEK 2, a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET and by GRD E-test] and confirmed by population analysis profile-(PAP. In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL genes and had indistinguishable PFGE patterns (subtype I2, thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I detected in our country. Conclusions This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to

Pediatric vancomycin use in 421 hospitals in the United States, 2008.

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Tamar Lasky

Full Text Available Recommendations to prevent the spread of vancomycin resistance have been in place since 1995 and include guidelines for inpatient pediatric use of vancomycin. The emergence of large databases allows us to describe variation in pediatric vancomycin across hospitals. We analyzed a database with hospitalizations for children under 18 at 421 hospitals in 2008.The Premier hospital 2008 database, consisting of records for 877,201 pediatric hospitalizations in 421 hospitals, was analyzed. Stratified analyses and logistic mixed effects models were used to calculate the probability of vancomycin use while considering random effects of hospital variation, hospital fixed effects and patient effects, and the hierarchical structure of the data. Most hospitals (221 had fewer than 10 hospitalizations with vancomycin use in the study period, and 47 hospitals reported no vancomycin use in 17,271 pediatric hospitalizations. At the other end of the continuum, 21 hospitals (5.6% of hospitals each had over 200 hospitalizations with vancomycin use, and together, accounted for more than 50% of the pediatric hospitalizations with vancomycin use. The mixed effects modeling showed hospital variation in the probability of vancomycin use that was statistically significant after controlling for teaching status, urban or rural location, size, region of the country, patient ethnic group, payor status, and APR-mortality and severity codes.The number and percentage of pediatric hospitalizations with vancomycin use varied greatly across hospitals and was not explained by hospital or patient characteristics in our logistic models. Public health efforts to reduce vancomycin use should be intensified at hospitals with highest use.

Surveillance and endemic vancomycin-resistant enterococci: some success in control is possible.

LENUS (Irish Health Repository)

Morris-Downes, M

2010-07-01

Vancomycin-resistant enterococci (VRE) are prevalent in many Irish hospitals. We analysed surveillance data from 2001 to 2008 in a centre where VRE is endemic. All clinically significant enterococci were tested for susceptibility to vancomycin. All intensive care unit admissions were screened on admission and weekly thereafter. Interventions included isolating\\/cohorting VRE patients, monthly prevalence surveys of VRE patients, the introduction of an electronic alert system, programmes to improve hand and environmental hygiene, and the appointment of an antibiotic pharmacist. There was a significant increase in the number of positive VRE screening samples from 2001 (1.96 patients with positive VRE screens per 10 000 bed-days) to 2006 (4.98 per 10 000 bed-days) (P < or = 0.001) with a decrease in 2007 (3.18 per 10 000 bed-days) (P < or = 0.01). The number of VRE bloodstream infections (BSI) increased from 0.09 BSI per 10 000 bed-days in 2001 to 0.78 per 10 000 bed-days in 2005 (P < or = 0.001) but decreased subsequently. Linear regression analysis indicated a significant association between new cases of VRE and non-isolated VRE patients, especially between May 2005 and December 2006 [P=0.009; 95% confidence interval (CI): 0.08-0.46] and between May 2005 and December 2008 (P = 0.008; 95% CI: 0.06-0.46). Routine surveillance for VRE together with other measures can control VRE BSI and colonisation, even where VRE is endemic, and where facilities are constrained.

In vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, bacitracin, and four other antimicrobials against intestinal anaerobic bacteria.

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Citron, D M; Merriam, C V; Tyrrell, K L; Warren, Y A; Fernandez, H; Goldstein, E J C

2003-07-01

By using an agar dilution method, the in vitro activities of ramoplanin, teicoplanin, vancomycin, linezolid, and five other agents were determined against 300 gram-positive and 54 gram-negative strains of intestinal anaerobes. Ramoplanin was active at Eubacterium, Actinomyces, Propionibacterium, and Peptostreptococcus spp. were inhibited by spp. were >or=256 microg/ml. Ramoplanin displays excellent activity against C. difficile and other gram-positive enteric anaerobes, including vancomycin-resistant strains; however, it has poor activity against most gram-negative anaerobes and thus potentially has a lesser effect on the ecological balance of normal fecal flora.

In vitro activity of flomoxef and cefazolin in combination with vancomycin.

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Simon, C; Simon, M

1991-01-01

207 clinical isolates from strains of patients from the University Children's Hospital of Kiel were investigated for their in vitro activity with the agar dilution method against flomoxef and cefazolin (alone and partially in combination with vancomycin). Staphylococci were also tested with other cephalosporins (cefoxitin, cefamandole, cefotaxime, cefotetan and latamoxef). Flomoxef and cefazolin always acted more vigorously on staphylococci than the other cephalosporins. Resistance of Staphylococcus aureus strains against flomoxef and cefazolin did not occur but was found in 15 and 5 of 98 Staphylococcus epidermidis strains, respectively. Enterococcus faecalis strains were always resistant against both drugs; Streptococcus faecium strains were only moderately sensitive. Combined testing of flomoxef or cefazolin with vancomycin showed synergism in almost all staphylococcal strains. Synergism was stronger when S. epidermidis strains were only weakly sensitive to or resistant against flomoxef and cefazolin in comparison to highly sensitive strains. Flomoxef (or cefazolin) acted synergistically in combination with vancomycin on E. faecalis and S. faecium with the exception of two strains of E. faecalis which showed an additive effect of both drugs.

The Impact of AUC-Based Monitoring on Pharmacist-Directed Vancomycin Dose Adjustments in Complicated Methicillin-Resistant Staphylococcus aureus Infection.

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Stoessel, Andrew M; Hale, Cory M; Seabury, Robert W; Miller, Christopher D; Steele, Jeffrey M

2018-01-01

This study aimed to assess the impact of area under the curve (AUC)-based vancomycin monitoring on pharmacist-initiated dose adjustments after transitioning from a trough-only to an AUC-based monitoring method at our institution. A retrospective cohort study of patients treated with vancomycin for complicated methicillin-resistant Staphylococcus aureus (MRSA) infection between November 2013 and December 2016 was conducted. The frequency of pharmacist-initiated dose adjustments was assessed for patients monitored via trough-only and AUC-based approaches for trough ranges: 10 to 14.9 mg/L and 15 to 20 mg/L. Fifty patients were included: 36 in the trough-based monitoring and 14 in the AUC-based-monitoring group. The vancomycin dose was increased in 71.4% of patients when troughs were 10 to 14.9 mg/L when a trough-only approach was used and in only 25% of patients when using AUC estimation ( P = .048). In the AUC group, the dose was increased only when AUC/minimum inhibitory concentration (MIC) AUC/MIC ≥400. The AUC-based monitoring did not significantly increase the frequency of dose reductions when trough concentrations were 15 to 20 mg/L (AUC: 33.3% vs trough: 4.6%; P = .107). The AUC-based monitoring resulted in fewer patients with dose adjustments when trough levels were 10 to 14.9 mg/L. The AUC-based monitoring has the potential to reduce unnecessary vancomycin exposure and warrants further investigation.

Is Vancomycine Still a Choice for Chronic Osteomyelitis Empirical Therapy in Iran?

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Izadi, Morteza; Zamani, Mohammad Mahdi; Mousavi, Seyed Ahmad; Sadat, Seyed Mir Mostafa; Siami, Zeinab; Vais Ahmadi, Noushin; Jonaidi Jafari, Nematollah; Shirvani, Shahram; Majidi Fard, Mojgan; Imani Fooladi, Abbas Ali

2012-01-01

Background Pyogenic bacteria and especially Staphylococcus aurous (S. aurous) are the most common cause of chronic osteomyelitis. Not only treatment protocol of chronic osteomyelitis occasionally is amiss but also this malady responds to treatment difficultly. Objectives This study investigates antibiotic resistance pattern of S. aurous isolated from Iranian patients who suffer from chronic osteomyelitis by two methods: disk diffusion (Kirby bauyer) and E-test (Epsilometer test) to find Vancomycin susceptibility and MIC (Minimum inhibitory concentration). Patients and Methods One hundred and thirty one patients who suffer from chronic osteomyelitis which have been referred to both governmental and private hospitals at 2010 were tried out for culturing of osteomyelitis site (sites). Antibiotic susceptibility and MIC of isolated bacteria were investigated by Kirby bauyer and E-test respectively. Results Samples were collected from bone (73.4%), surrounding tissue (14.6%) and wound discharge (12%). S. aureus was isolated from 49.6% of the samples. According to disc diffusion, methicillin resistance S. aureus (MRSA) was 75% and Vancomycin resistance S. aurous (VRSA) was 0% and based on MIC, MRSA was 68.5% and VRSA was 0%. According to MIC experiments, maximum sensitivity was against to Vancomycin (90.2%) and ciprofloxacin (54.4%) respectively but based on disc diffusion, maximum sensitivity was against to Vancomycin (97.7%) and ciprofloxacin (43.2%), respectively (P = 0.001). E-test (9.8%) in comparison with Disc diffusion (2.3%) showed higher percent of intermediate susceptibility to Vancomycin (P = 0.017). Conclusions Comparison of antibiograms and MICs showed that Kirby bauyer technique especially for detection of VISA strains is not reliable comparison with E-test. Already VRSA strains have not detected in Iranian chronic osteomyelitis, Thus Vancomycin is the first choice for chronic osteomyelitis empirical therapy in Iran yet. PMID:23483042

Clostridium difficile Infection and Patient-Specific Antimicrobial Resistance Testing Reveals a High Metronidazole Resistance Rate.

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Barkin, Jodie A; Sussman, Daniel A; Fifadara, Nimita; Barkin, Jamie S

2017-04-01

Clostridium difficile (CD) infection (CDI) causes marked morbidity and mortality, accounting for large healthcare expenditures annually. Current CDI treatment guidelines focus on clinical markers of patient severity to determine the preferred antibiotic regimen of metronidazole versus vancomycin. The antimicrobial resistance patterns for patients with CD are currently unknown. The aim of this study was to define the antimicrobial resistance patterns for CD. This study included all patients with stools sent for CD testing to a private laboratory (DRG Laboratory, Alpharetta, Georgia) in a 6-month period from across the USA. Patient data was de-identified, with only age, gender, and zip-code available per laboratory protocol. All samples underwent PCR testing followed by hybridization for CD toxin regions A and B. Only patients with CD-positive PCR were analyzed. Antimicrobial resistance testing using stool genomic DNA evaluated presence of imidazole- and vancomycin-resistant genes using multiplex PCR gene detection. Of 2743, 288 (10.5%) stool samples were positive for CD. Six were excluded per protocol. Of 282, 193 (69.4%) were women, and average age was 49.4 ± 18.7 years. Of 282, 62 were PCR positive for toxins A and B, 160 for toxin A positive alone, and 60 for toxin B positive alone. Antimicrobial resistance testing revealed 134/282 (47.5%) patients resistant to imidazole, 17 (6.1%) resistant to vancomycin, and 9 (3.2%) resistant to imidazole and vancomycin. CD-positive patients with presence of imidazole-resistant genes from stool DNA extract was a common phenomenon, while vancomycin resistance was uncommon. Similar to treatment of other infections, antimicrobial resistance testing should play a role in CDI clinical decision-making algorithms to enable more expedited and cost-effective delivery of patient care.

Evaluation of contact precautions for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus.

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Bardossy, Ana Cecilia; Alsafadi, Muhammad Yasser; Starr, Patricia; Chami, Eman; Pietsch, Jennifer; Moreno, Daniela; Johnson, Laura; Alangaden, George; Zervos, Marcus; Reyes, Katherine

2017-12-01

There are limited controlled data demonstrating contact precautions (CPs) prevent methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) infections in endemic settings. We evaluated changes in hospital-acquired MRSA and VRE infections after discontinuing CPs for these organisms. This is a retrospective study done at an 800-bed teaching hospital in urban Detroit. CPs for MRSA and VRE were discontinued hospital-wide in 2013. Data on MRSA and VRE catheter-associated urinary tract infections (CAUTIs), ventilator-associated pneumonia (VAP), central line-associated bloodstream infections (CLABSIs), surgical site infections (SSIs), and hospital-acquired MRSA bacteremia (HA-MRSAB) rates were compared before and after CPs discontinuation. There were 36,907 and 40,439 patients hospitalized during the two 12-month periods: CPs and no CPs. Infection rates in the CPs and no-CPs periods were as follows: (1) MRSA infections: VAP, 0.13 versus 0.11 (P = .84); CLABSI, 0.11 versus 0.19 (P = .45); SSI, 0 versus 0.14 (P = .50); and CAUTI, 0.025 versus 0.033 (P = .84); (2) VRE infections: CAUTI, 0.27 versus 0.13 (P = .19) and CLABSI, 0.29 versus 0.3 (P = .94); and (3) HA-MRSAB rates: 0.14 versus 0.11 (P = .55), respectively. Discontinuation of CPs did not adversely impact endemic MRSA and VRE infection rates. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Reconsidering contact precautions for endemic methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus.

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Morgan, Daniel J; Murthy, Rekha; Munoz-Price, L Silvia; Barnden, Marsha; Camins, Bernard C; Johnston, B Lynn; Rubin, Zachary; Sullivan, Kaede V; Shane, Andi L; Dellinger, E Patchen; Rupp, Mark E; Bearman, Gonzalo

2015-10-01

Whether contact precautions (CP) are required to control the endemic transmission of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in acute care hospitals is controversial in light of improvements in hand hygiene, MRSA decolonization, environmental cleaning and disinfection, fomite elimination, and chlorhexidine bathing. To provide a framework for decision making around use of CP for endemic MRSA and VRE based on a summary of evidence related to use of CP, including impact on patients and patient care processes, and current practices in use of CP for MRSA and VRE in US hospitals. A literature review, a survey of Society for Healthcare Epidemiology of America Research Network members on use of CP, and a detailed examination of the experience of a convenience sample of hospitals not using CP for MRSA or VRE. Hospital epidemiologists and infection prevention experts. No high quality data support or reject use of CP for endemic MRSA or VRE. Our survey found more than 90% of responding hospitals currently use CP for MRSA and VRE, but approximately 60% are interested in using CP in a different manner. More than 30 US hospitals do not use CP for control of endemic MRSA or VRE. Higher quality research on the benefits and harms of CP in the control of endemic MRSA and VRE is needed. Until more definitive data are available, the use of CP for endemic MRSA or VRE in acute care hospitals should be guided by local needs and resources.

Successful prevention of the transmission of vancomycin-resistant enterococci in a Brazilian public teaching hospital

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Flávia Alves Ferreira Rossini

2012-04-01

Full Text Available INTRODUCTION: Vancomycin-resistant enterococci (VRE can colonize or cause infections in high-risk patients and contaminate the environment. Our objective was to describe theepidemiological investigation of an outbreak of VRE, the interventions made, and their impact on its control. METHODS: We conducted a retrospective, descriptive, non-comparative study by reviewing the charts of patients with a VRE-positive culture in the University Hospital of Campinas State University, comprising 380 beds, 40 of which were in intensive care units (ICUs, who were admitted from February 2008-January 2009. Interventions were divided into educational activity, reviewing the workflow processes, engineering measures, and administrative procedures. RESULTS: There were 150 patients, 139 (92.7% colonized and 11 (7.3% infected. Seventy-three percent were cared for in non-ICUs (p = 0.028. Infection was more frequent in patients with a central-line (p = 0.043, mechanical ventilation (p = 0.013, urinary catheter (p = 0.049, or surgical drain (p = 0.049. Vancomycin, metronidazole, ciprofloxacin, and third-generation cephalosporin were previously used by 47 (31.3%, 31 (20.7%, 24 (16%, and 24 (16% patients, respectively. Death was more frequent in infected (73% than in colonized (17% patients (p < 0.001. After the interventions, the attack rate fell from 1.49 to 0.33 (p < 0.001. CONCLUSIONS: Classical risk factors for VRE colonization or infection, e.g., being cared for in an ICU and previous use of vancomycin, were not found in this study. The conjunction of an educational program, strict adhesion to contact precautions, and reinforcement of environmental cleaning were able to prevent the dissemination of VRE.

An economic model to compare linezolid and vancomycin for the treatment of confirmed methicillin-resistant Staphylococcus aureus nosocomial pneumonia in Germany

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Patel DA

2014-10-01

Full Text Available Dipen A Patel,1 Andre Michel,2 Jennifer Stephens,1 Bertram Weber,3 Christian Petrik,4 Claudie Charbonneau5 1Health Economic and Outcomes Research, Pharmerit International, Bethesda, MD, USA; 2Klinikum Hanau GmbH, Hanau, Germany; 3Health Technology Assessment and Outcomes Research, 4Anti-infectives, Pfizer, Berlin, Germany; 5Pfizer International Operations, Pfizer France, Paris, France Background: Across Europe, methicillin-resistant Staphylococcus aureus (MRSA is considered to be the primary cause of nosocomial pneumonia (NP. In Germany alone, approximately 14,000 cases of MRSA-associated NP occur annually, which may have a significant impact on health care resource use and associated economic costs. The objective of this study was to investigate the economic impact of linezolid compared with that of vancomycin in the treatment of hospitalized patients with MRSA-confirmed NP in the German health care system. Methods: A 4-week decision tree model incorporated published data and expert opinion on clinical parameters, resource use, and costs (2012 euros was constructed. The base case first-line treatment duration for patients with MRSA-confirmed NP was 10 days. Treatment success (survival, failure due to lack of efficacy, serious adverse events, and mortality were possible outcomes that could impact costs. Alternate scenarios were analyzed, such as varying treatment duration (7 or 14 days or treatment switch due to a serious adverse event/treatment failure (at day 5 or 10. Results: The model calculated total base case inpatient costs of €15,116 for linezolid and €15,239 for vancomycin. The incremental cost-effectiveness ratio favored linezolid (versus vancomycin, with marginally lower costs (by €123 and greater efficacy (+2.7% absolute difference in the proportion of patients successfully treated for MRSA NP. Approximately 85%–87% of the total treatment costs were attributed to hospital stay (primarily in the intensive care unit

Plectranthus amboinicus essential oil and carvacrol bioactive against planktonic and biofilm of oxacillin- and vancomycin-resistant Staphylococcus aureus.

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Vasconcelos, Sara Edwirgens Costa Benício; Melo, Hider Machado; Cavalcante, Theodora Thays Arruda; Júnior, Francisco Eduardo Aragão Catunda; de Carvalho, Mário Geraldo; Menezes, Francisca Gleire Rodrigues; de Sousa, Oscarina Viana; Costa, Renata Albuquerque

2017-09-16

The emergence of multidrug-resistant bacteria is a worldwide concern and in order to find an alternative to this problem, the occurrence of antimicrobial compounds in Plectranthus amboinicus essential oil was investigated. Thus, this study aims to determine susceptibility of Staphylococcus aureus isolated from food to antibiotics, P. amboinicus essential oil (PAEO) and carvacrol. Leaves and stem of P. amboinicus were used for extraction of essential oil (PAEO) by hydrodistillation technique and EO chemical analysis was performed by gas chromatography coupled to a mass spectrometer. S. aureus strains (n = 35) isolated from food and S. aureus ATCC 6538 were used to evaluate the antimicrobial and antibiofilm activity of PAEO and carvacrol. All strains (n = 35) were submitted to antimicrobial susceptibility profile by disk diffusion method. Determination of MIC and MBC was performed by microdilution technique and antibiofilm activity was determined by microtiter-plate technique with crystal violet assay and counting viable cells in Colony Forming Units (CFU). Carvacrol (88.17%) was the major component in the PAEO. Antibiotic resistance was detected in 28 S. aureus strains (80%) and 12 strains (34.3%) were oxacillin and vancomycin-resistant (OVRSA). From the 28 resistant strains, 7 (25%) showed resistance plasmid of 12,000 bp. All strains (n = 35) were sensitive to PAEO and carvacrol, with inhibition zones ranging from 16 to 38 mm and 23 to 42 mm, respectively. The lowest MIC (0.25 mg mL -1 ) and MBC (0.5 mg mL -1 ) values were observed when carvacrol was used against OVRSA. When a 0.5 mg mL -1 concentration of PAEO and carvacrol was used, no viable cells were found on S. aureus biofilm. The antibacterial effect of carvacrol and PAEO proves to be a possible alternative against planktonic forms and staphylococcal biofilm.

Efficacy of linezolid compared to vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus in ventilated pigs.

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Martinez-Olondris, Pilar; Rigol, Montserrat; Soy, Dolors; Guerrero, Laura; Agusti, Carlos; Quera, Maria Angels; Li Bassi, Gianluigi; Esperatti, Mariano; Luque, Nestor; Liapikou, Manto; Filella, Xavier; Marco, Francesc; de la Bellacasa, Jordi Puig; Torres, Antoni

2012-01-01

To assess the efficacy of linezolid compared with vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) in ventilated pigs. Forty pigs (30 kg) were intubated and challenged via bronchoscopy with a suspension of 106 colony forming units of MRSA into every lobe. Afterwards, pigs were ventilated up to 96 hours. Twelve hours after bacterial inoculation, the animals were randomized into 4 groups of treatment: group 1, control; group 2, vancomycin twice daily; group 3, continuous infusion of vancomycin; and group 4, linezolid. Clinical and laboratory parameters were monitored throughout the study. Bacterial cultures of bronchoalveolar lavage fluid and lung tissue samples were performed at the end of the study. Measurements of histopathology derangements of lung samples and studies of intrapulmonary drug penetration were performed. A total of 34 animals completed the study. No differences in clinical and laboratory parameters were observed. The percentage of bronchoalveolar lavage fluid and lung tissue samples with positive cultures for MRSA in controls and groups 2, 3, and 4 was respectively 75%, 11%, 11%, and 0% (p pneumonia in 95%, 69%, 58%, and 57% and signs of severe pneumonia in 48%, 29%, 22%, and 0% of controls and groups 2, 3, and 4, respectively (p treatments. In this animal model of MRSA pneumonia, linezolid showed a better efficacy than vancomycin showed because of a better pharmacokinetics/pharmacodynamics index.

Isolation of vancomycin resistant Enterococcus faecium from food

DEFF Research Database (Denmark)

Wegener, Henrik Caspar; Madsen, Mogens; Nielsen, Niels

1997-01-01

was not detected in 124 samples of pork and 128 samples of beef from retail outlets by the direct plating method. An additional enrichment step in nutrient broth supplemented with vancomycin enhanced the detection rate of VREF by approximately three times compared to the direct plating method when investigating...... the same 160 samples of broilers by the two methods. The implications and public health aspects of VREF in food is discussed....

In vitro synergy of baicalein and gentamicin against vancomycin-resistant Enterococcus.

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Chang, Ping Chin; Li, Hua Yu; Tang, Hung Jen; Liu, Jien Wei; Wang, Jhi Joung; Chuang, Yin Ching

2007-02-01

Little is known about the possible synergism of baicalein, a bioactive flavone of Scutellariae radix (a Chinese herb), when used in conjunction with other antimicrobial agents against vancomycin-resistant Enterococcus (VRE). This in vitro study examined the possible synergism of the combination of baicalein and gentamicin against VRE. Minimal inhibitory concentrations (MICs) of baicalein as well as gentamicin were determined against 39 clinical isolates of VRE by the agar dilution method. Synergistic activities were determined using the checkerboard method based on the fractional inhibitory concentration indices and also the time-kill method. Further time-kill studies were conducted with these two agents against one randomly chosen clinical isolate, VRE-096. Minimal concentrations inhibiting 50% (MIC(50)) and 90% (MIC(90)) of isolates for baicalein and gentamicin were all >256 microg/mL. Synergism between baicalein and gentamicin was demonstrated against four clinical isolates of VRE (VRE-70, VRE-940, VRE-096 and VRE-721). When approximately 5 x 10(5) colony-forming units/mL of VRE-096 was incubated with both baicalein at a concentration of 32 microg/mL (1/8 x MIC) and gentamicin at a concentration of 128 microg/mL (1/2 x MIC), there was an inhibitory effect against VRE that persisted for 48 h. At 48 h, the combination of baicalein and gentamicin at these respective concentrations resulted in a reduction of growth by approximately 2 orders of magnitude compared to that for the starting inoculum and by 3 orders of magnitude compared to that for baicalein alone, the more active single agent. This study demonstrated that baicalein and gentamicin can act synergistically in inhibiting VRE in vitro.

In Vitro Assessment of Electric Currents Increasing the Effectiveness of Vancomycin Against Staphylococcus epidermidis Biofilms.

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Haddad, Peter A; Mah, Thien-Fah; Mussivand, Tofy

2016-08-01

Biofilms are communities of bacteria that can cause infections which are resistant to the immune system and antimicrobial treatments, posing a significant threat for patients with implantable and indwelling medical devices. The purpose of our research was to determine if utilizing specific parameters for electric currents in conjunction with antibiotics could effectively treat a highly resistant biofilm. Our study evaluated the impact of 16 μg/mL of vancomycin with or without 22 or 333 μA of direct electric current (DC) generated by stainless steel electrodes against 24-, 48-, and 72-h-old Staphylococcus epidermidis biofilms formed on titanium coupons. An increase in effectiveness of vancomycin was observed with the combination of 333 μA of electric current against 48-h-old biofilms (P value = 0.01) as well as in combination with 22 μA of electric current against 72-h-old biofilms (P value = 0.04); 333 μA of electric current showed the most significant impact on the effectiveness of vancomycin against S. epidermidis biofilms demonstrating a bioelectric effect previously not observed against this strain of bacteria. © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Modulating activity of vancomycin and daptomycin on the expression of autolysis cell-wall turnover and membrane charge genes in hVISA and VISA strains.

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Viviana Cafiso

Full Text Available Glycopeptides are still the gold standard to treat MRSA (Methicillin Resistant Staphylococcus aureus infections, but their widespread use has led to vancomycin-reduced susceptibility [heterogeneous Vancomycin-Intermediate-Staphylococcus aureus (hVISA and Vancomycin-Intermediate-Staphylococcus aureus (VISA], in which different genetic loci (regulatory, autolytic, cell-wall turnover and cell-envelope positive charge genes are involved. In addition, reduced susceptibility to vancomycin can influence the development of resistance to daptomycin. Although the phenotypic and molecular changes of hVISA/VISA have been the focus of different papers, the molecular mechanisms responsible for these different phenotypes and for the vancomycin and daptomycin cross-resistance are not clearly understood. The aim of our study was to investigate, by real time RT-PCR, the relative quantitative expression of genes involved in autolysis (atl-lytM, cell-wall turnover (sceD, membrane charges (mprF-dltA and regulatory mechanisms (agr-locus-graRS-walKR, in hVISA and VISA cultured with or without vancomycin and daptomycin, in order to better understand the molecular basis of vancomycin-reduced susceptibility and the modulating activity of vancomycin and daptomycin on the expression of genes implicated in their reduced susceptibility mechanisms. Our results show that hVISA and VISA present common features that distinguish them from Vancomycin-Susceptible Staphylococcus aureus (VSSA, responsible for the intermediate glycopeptide resistance i.e. an increased cell-wall turnover, an increased positive cell-wall charge responsible for a repulsion mechanism towards vancomycin and daptomycin, and reduced agr-functionality. Indeed, VISA emerges from hVISA when VISA acquires a reduced autolysis caused by a down-regulation of autolysin genes, atl/lytM, and a reduction of the net negative cell-envelope charge via dltA over-expression. Vancomycin and daptomycin, acting in a similar

Phenotypic and genomic comparisons of highly vancomycin-resistant Staphylococcus aureus strains developed from multiple clinical MRSA strains by in vitro mutagenesis.

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Ishii, Kenichi; Tabuchi, Fumiaki; Matsuo, Miki; Tatsuno, Keita; Sato, Tomoaki; Okazaki, Mitsuhiro; Hamamoto, Hiroshi; Matsumoto, Yasuhiko; Kaito, Chikara; Aoyagi, Tetsuji; Hiramatsu, Keiichi; Kaku, Mitsuo; Moriya, Kyoji; Sekimizu, Kazuhisa

2015-11-25

The development of vancomycin (VCM) resistance in Staphylococcus aureus threatens global health. Studies of the VCM-resistance mechanism and alternative therapeutic strategies are urgently needed. We mutagenized S. aureus laboratory strains and methicillin-resistant S. aureus (MRSA) with ethyl methanesulfonate, and isolated mutants that exhibited high resistance to VCM (minimum inhibitory concentration = 32 μg/ml). These VCM-resistant strains were sensitive to linezolid and rifampicin, and partly to arbekacin and daptomycin. Beta-lactams had synergistic effects with VCM against these mutants. VCM-resistant strains exhibited a 2-fold increase in the cell wall thickness. Several genes were commonly mutated among the highly VCM-resistant mutants. These findings suggest that MRSA has a potential to develop high VCM resistance with cell wall thickening by the accumulation of mutations.

Characterization and modelling of VanT: a novel, membrane-bound, serine racemase from vancomycin-resistant Enterococcus gallinarum BM4174.

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Arias, C A; Martín-Martinez, M; Blundell, T L; Arthur, M; Courvalin, P; Reynolds, P E

1999-03-01

Sequence determination of a region downstream from the vanXYc gene in Enterococcus gallinarum BM4174 revealed an open reading frame, designated vanT, that encodes a 698-amino-acid polypeptide with an amino-terminal domain containing 10 predicted transmembrane segments. The protein contained a highly conserved pyridoxal phosphate attachment site in the C-terminal domain, typical of alanine racemases. The protein was overexpressed in Escherichia coli, and serine racemase activity was detected in the membrane but not in the cytoplasmic fraction after centrifugation of sonicated cells, whereas alanine racemase activity was located almost exclusively in the cytoplasm. When the protein was overexpressed as a polypeptide lacking the predicted transmembrane domain, serine racemase activity was detected in the cytoplasm. The serine racemase activity was partially (64%) inhibited by D-cycloserine, whereas host alanine racemase activity was almost totally inhibited (97%). Serine racemase activity was also detected in membrane preparations of constitutively vancomycin-resistant E. gallinarum BM4174 but not in BM4175, in which insertional inactivation of the vanC-1 D-Ala:D-Ser ligase gene probably had a polar effect on expression of the vanXYc and vanT genes. Comparative modelling of the deduced C-terminal domain was based on the alignment of VanT with the Air alanine racemase from Bacillus stearothermophilus. The model revealed that almost all critical amino acids in the active site of Air were conserved in VanT, indicating that the C-terminal domain of VanT is likely to adopt a three-dimensional structure similar to that of Air and that the protein could exist as a dimer. These results indicate that the source of D-serine for peptidoglycan synthesis in vancomycin-resistant enterococci expressing the VanC phenotype involves racemization of L- to D-serine by a membrane-bound serine racemase.

Investigation of the potential for mutational resistance to XF-73, retapamulin, mupirocin, fusidic acid, daptomycin, and vancomycin in methicillin-resistant Staphylococcus aureus isolates during a 55-passage study.

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Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

2011-03-01

XF-73 is a dicationic porphyrin drug with rapid Gram-positive antibacterial activity currently undergoing clinical trials for the nasal decolonization of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). In multistep (55-passage) resistance selection studies in the presence of subinhibitory concentrations of XF-73, retapamulin, mupirocin, fusidic acid, and vancomycin against four Network on Antimicrobial Resistance in Staphylococcus aureus MRSA strains, there was no >4-fold increase in the MIC for XF-73 after 55 passages. In contrast, there was an increase in the MICs for retapamulin (from 0.25 μg/ml to 4 to 8 μg/ml), for mupirocin (from 0.12 μg/ml to 16 to 512 μg/ml), for fusidic acid (from 0.12 μg/ml to 256 μg/ml), and for vancomycin (from 1 μg/ml to 8 μg/ml in two of the four strains tested). Further investigations using S. aureus NRS384 (USA300) and daptomycin demonstrated a 64-fold increase in the MIC after 55 passages (from 0.5 μg/ml to 32 μg/ml) with a >4-fold increase in the MIC obtained after only five passages. Sequencing analysis of selected isolates confirmed previously reported point mutations associated with daptomycin resistance. No cross-resistance to XF-73 was observed with the daptomycin-resistant strains, suggesting that whereas the two drugs act on the bacterial cell membrane, their specific site of action differs. XF-73 thus represents the first in a new class of antibacterial drugs, which (unlike the comparator antibiotics) after 55 passages exhibited a ≤4-fold increase in MIC against the strains tested. Antibacterial drugs with a low propensity for inducing bacterial resistance are much needed for the prevention and treatment of multidrug-resistant bacteria both within and outside the hospital setting.

Antimicrobial susceptibility against penicillin, ampicillin and vancomycin of viridans group Streptococcus in oral microbiota of patients at risk of infective endocarditis.

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Süzük, Serap; Kaşkatepe, Banu; Çetin, Mustafa

2016-09-01

The viridans group Streptococci (VGS) are most abundant in the mouth; in some instances they might emerge as pathogens particularly in infective endocarditis (IE). In this study, we aimed to define and determine the susceptibility against antibiotics of VGS that are members of the oral microbiota of patients exhibiting a risk of developing IE. Forty-nine patients at risk of infective endocarditis were included in the study. Identification of the bacteria was performed using API STREP (bioMérieux, France). Gradient test strips (E-Test, France) were used to determine MIC of the bacteria against penicillin, ampicillin, and vancomycin. The distribution of the isolated VGS groups was determined as follows: Streptococcus mitis 32.6% and anginosus group - 32.6%, S. sanguinis group - 16.3%, S. mutans group - 12.2%, and S. salivarius group - 6.1%. The rates of resistance and reduced sensitivity of the isolates for penicillin and ampicillin were determined at 61.2% and 55.1%, respectively. However, all isolates were found to be susceptible to vancomycin. We conclude that the antimicrobial resistance of VGS should be determined on a regular basis locally, and decisions on therapeutic and prophylactic interventions should be given taking this resistance into consideration.

Comparing the ocular surface effects of topical vancomycin and linezolid for treating bacterial keratitis.

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Akova Budak, Berna; Baykara, Mehmet; Kıvanç, Sertaç Argun; Yilmaz, Hakan; Cicek, Serhat

2016-01-01

Vancomycin is the gold standard in combination therapy for severe and resistant gram-positive keratitis and in particular for Methicillin-resistant Staphylococcus aureus (MRSA) infections. The aim of this study was to report the ocular surface toxicity and scoring in patients whose treatment shifted to topical linezolid/ceftazidime from topical vancomycin/ceftazidime due to their vancomycin intolerance. A retrospective, interventional case series of bacterial keratitis was treated with topical linezolid (one drop of 0.2% solution per eye), administered hourly until epithelization and then gradually decreased. The number and extent of punctate epithelial erosions were noted across the entire surface of the cornea. Ocular discomfort was assessed by means of (a) patient-reported pain upon instillation of the medication (vancomycin/linezolid), (b) reported burning sensation between doses and (c) reported foreign-body sensation. No ocular surface toxicity related to linezolid use was noted. Patients were followed for at least 2 months after treatment between April and December 2013. Of the seven patients included in the study (age range: 2-88 years; five females, two males), complete epithelization and resolution was achieved in five patients. One patient was treated with linezolid after penetrating keratoplasty. The second culture of another patient with impending perforation despite linezolid/ceftazidime therapy yielded Fusarium spp., so he underwent tectonic keratoplasty. The mean ocular surface score was 9.4 ± 1.6 during vancomycin treatment and 5.9 ± 1.3 during linezolid treatment after discontinuation of vancomycin. The topical linezolid score was significantly lower (p = 0.027). Topical linezolid may be better tolerated, according to the mean ocular surface score, than topical vancomycin by some patients and can be considered an alternative for patients who do not well tolerate vancomycin.

Gene Expression Analysis Reveals New Possible Mechanisms of Vancomycin-Induced Nephrotoxicity and Identifies Gene Markers Candidates

OpenAIRE

Dieterich, Christine; Puey, Angela; Lyn, Sylvia; Swezey, Robert; Furimsky, Anna; Fairchild, David; Mirsalis, Jon C.; Ng, Hanna H.

2008-01-01

Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip administration. Groups of six female BALB/c mice were treated with seven daily iv or ip doses of vancomycin (50, 200, and 400 mg/kg) or saline, and...

Balancing vancomycin efficacy and nephrotoxicity: should we be aiming for trough or AUC/MIC?

Science.gov (United States)

Patel, Karisma; Crumby, Ashley S; Maples, Holly D

2015-04-01

Sixty years later, the question that still remains is how to appropriately utilize vancomycin in the pediatric population. The Infectious Diseases Society of America published guidelines in 2011 that provide guidance for dosing and monitoring of vancomycin in adults and pediatrics. However, goal vancomycin trough concentrations of 15-20 μg/mL for invasive infections caused by methicillin-resistant Staphylococcus aureus were based primarily on adult pharmacokinetic and pharmacodynamic data that achieved an area under the curve to minimum inhibitory concentration ratio (AUC/MIC) of ≥400. Recent pediatric literature shows that vancomycin trough concentrations needed to achieve the target AUC/MIC are different than the adult goal troughs cited in the guidelines. This paper addresses several thoughts, including the role of vancomycin AUC/MIC in dosing strategies and safety monitoring, consistency in laboratory reporting, and future directions for calculating AUC/MIC in pediatrics.

Human and Swine Hosts Share Vancomycin-Resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 Clonal Clusters Harboring Tn1546 on Indistinguishable Plasmids

DEFF Research Database (Denmark)

Freitas, Ana R.; Coque, Teresa M.; Novais, Carla

2011-01-01

clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST...... comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn1546 (encoding...... resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep(pLG1)). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep(Inc18) plus rep...

Vancomycin, linezolid and daptomycin susceptibility pattern among clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA from Sub- Himalyan Center

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Afzal Husain

2018-01-01

CONCLUSION: MIC creep was observed with vancomycin. Although linezolid MIC was within the susceptible zone, more than 40% strains showing MIC 3 μg/ml may herald the future development of either resistant or heteroresistant. Daptomycin showed good sensitivity against MRSA isolates. Therefore, it could be considered as an alternative agent for the treatment of infections caused by MRSA. However, it should be reserved where this class has a clear therapeutic advantage over other anti-MRSA drugs.

A specially tailored vancomycin continuous infusion regimen for renally impaired critically ill patients

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Eman Mohamed Bahgat Eldemiry

2013-10-01

Full Text Available Background: Vancomycin remains the gold standard for treatment of methicillin-resistant Staphylococcus aureus. Specially designed continuous infusion of vancomycin leads to better therapy. Methodology: A total of 40 critically ill patients who suffered from pneumonia susceptible to vancomycin, had serum creatinine >1.4 mg%, and oliguria <0.5 mL/kg/h for 6 h were included in the study with respiratory culture sensitivity to vancomycin ≤2 mg/L. Patients’ clinical, microbiological, and biological data were obtained by retrospective analysis of the corresponding medical files before and after vancomycin treatment. Patients with serum creatinine level ≥4 mg% and patients who received renal replacement therapy during the treatment period were excluded. The patients were divided into two groups—group 1 (intermittent dosing and group 2 (continuous infusion based on the following formula: rate of vancomycin continuous infusion (g/day = [0.0205 creatinine clearance (mL/min + 3.47] × [target vancomycin concentration at steady state (µg/mL] × (24/1000. Trough vancomycin serum levels were also assessed using high-performance liquid chromatographic technique. Patients’ outcomes such as clinical improvement, adverse events, and 15-day mortality were reported. Results: Group 2 showed significant reduction in blood urea nitrogen, creatinine serum levels, white blood cells, partial carbon dioxide pressure, body temperature, and Sequential Organ Failure Assessment score, while significant increase in partial oxygen pressure and saturated oxygen was also observed. A significantly shorter duration of treatment with a comparable vancomycin serum levels was also reported with group 2. Conclusion: After treatment, comparison in patients’ criteria supports the superiority of using continuous infusion of vancomycin according to this equation in renally impaired patients.

Vancomycin-induced thrombocytopenia in a 60-year-old man: a case report

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Shah Ravish A

2009-06-01

Full Text Available Abstract Introduction Vancomycin, a glycopeptide antibiotic, is used to treat resistant gram-positive infections. There has been a 10- to 20-fold increase in its use over the past 25 years. Although ototoxicity and nephrotoxicity are well known side effects of vancomycin, it can also induce platelet reactive antibodies leading to life-threatening thrombocytopenia. Vancomycin is often clinically overlooked as a cause of thrombocytopenia, especially in a scenario of sepsis or when there is use of heparin. We report a proven case of vancomycin-induced thrombocytopenia and its reversal after discontinuation of vancomycin. Case presentation A 60-year-old man with a history of hypertension, congestive heart failure and dyslipidemia was admitted for a right shoulder rotator cuff tear. He underwent right-shoulder arthroscopy and rotator cuff repair. About three weeks later, he developed pain, swelling and purulent drainage from his right shoulder. Arthroscopic irrigation and drainage was then performed. Intraoperative fluid revealed the presence of Methicillin susceptible Staphylococcus aureus, vancomycin-sensitive Enterococcus spp. and Serratia marcescens. The patient had no known allergies. After reviewing his antimicrobial susceptibility, he was started on vancomycin 1500 mgs intravenously every 12 hours (to treat both Staphylococcus aureus and Enterococcus spp and ciprofloxacin 750 mgs by oral induction every 12 hours. The patient's condition improved following antibiotic treatment. He was discharged and allowed to go home on IV vancomycin and oral ciprofloxacin. The patient's platelet count on the day of starting vancomycin therapy was 253 × 103/mm3. At weeks one, two and three, the counts were 231 × 103/mm3, 272 × 103/mm and 6 × 103/mm3, respectively. The patient was admitted for further work-up of the thrombocytopenia. He was later shown to have vancomycin-induced platelet-reactive antibodies, causing significant thrombocytopenia, and then

Auditory function after application of ototopical vancomycin and mupirocin solutions in a murine model.

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Rutherford, Kimberley D; Kavanagh, Katherine; Parham, Kourosh

2011-03-01

To determine whether mupirocin (440 µg/mL) and vancomycin otic drops (25 mg/mL) show evidence of ototoxicity in CBA/J mice immediately following a 7-day course of daily intratympanic (IT) injections and 1 month following treatment. Nonrandomized controlled trial. Academic hospital laboratory. Twenty CBA/J mice. Mean auditory brainstem response (ABR) thresholds increased in all drug- and saline-treated ears immediately after 7 days of IT injections but returned to baseline for most stimulus frequencies by 30 days later. This finding appeared to be correlated with the presence and subsequent resolution of tympanic membrane (TM) perforations and granulation tissue at the injection sites. Mupirocin-treated ears showed no significant difference in ABR thresholds compared to saline-treated ears. No significant differences were noted between vancomycin- and saline-treated ears, but there was a significant interaction between testing day and stimulus frequency (P injections (95% confidence interval, -13.5 to -5.5, P application of mupirocin solution (440 µg/mL) caused no significant change in the ABR thresholds in a murine model, vancomycin solution (25 mg/mL) resulted in high-frequency threshold elevations in both the ear directly injected and the contralateral ear. Mupirocin solution may be beneficial in managing otitis externa and media caused by resistant pathogens. Further studies of ototopical vancomycin are needed to define parameters governing its safe use.

The potential of vancomycin-resistant enterococci to persist in fermented and pasteurised meat products.

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Houben, J H

2003-11-15

Experiments with 148 isolates of vancomycin-resistant enterococci (VRE) were performed to assess their potential to persist and grow in fermented sausages and pasteurised meat products. All strains were meat isolates and Van-type A, except a single VanC1 strain. In total, 143 strains of Enterococcus faecium were involved. Eight selected strains were examined for their potential to grow at high salt and nitrite levels and at reduced pH. The same isolates were used in experiments with fermented sausages. All available strains were subjected to heating tests in meat suspensions with added curing ingredients. All but one of the eight tested isolates grew at pH 4.0 in tryptone soya broth (TSB). With the combination of 8% w/w NaCl, 400 ppm NaNO2 and 0.5% w/w glucose in the meat suspension, all isolates grew at 37 degrees C, whereas none grew at 7 degrees C even after 56 days. With the addition of 10% w/w NaCl, 200 ppm NaNO2 and 0.5% w/w glucose, still one E. faecium isolate grew at 37 degrees C, although very slowly. Overall, the strains tolerated high salt and nitrite concentrations and reduced pH very well, even beyond levels applied in the regular production of fermented and/or pasteurised meat products. The tested strains could be isolated after the fermentation and further ripening of "boerenmetworst" and "snijworst". Overall, their colony counts decreased on average about 1 log-unit over a period of 60 days after batter manufacture. All 148 isolates demonstrated a relatively weak thermal resistance compared to results for selected vancomycin-sensitive enterococci strains reported in the literature and to results collected under identical experimental conditions in this laboratory. None of the strains (log inoculation level about 5-6 ml(-1) for each isolate) could be cultured after heating at 70 degrees C for 10 min.

Controlling for endogeneity in attributable costs of vancomycin-resistant enterococci from a Canadian hospital.

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Lloyd-Smith, Patrick

2017-12-01

Decisions regarding the optimal provision of infection prevention and control resources depend on accurate estimates of the attributable costs of health care-associated infections. This is challenging given the skewed nature of health care cost data and the endogeneity of health care-associated infections. The objective of this study is to determine the hospital costs attributable to vancomycin-resistant enterococci (VRE) while accounting for endogeneity. This study builds on an attributable cost model conducted by a retrospective cohort study including 1,292 patients admitted to an urban hospital in Vancouver, Canada. Attributable hospital costs were estimated with multivariate generalized linear models (GLMs). To account for endogeneity, a control function approach was used. The analysis sample included 217 patients with health care-associated VRE. In the standard GLM, the costs attributable to VRE are $17,949 (SEM, $2,993). However, accounting for endogeneity, the attributable costs were estimated to range from $14,706 (SEM, $7,612) to $42,101 (SEM, $15,533). Across all model specifications, attributable costs are 76% higher on average when controlling for endogeneity. VRE was independently associated with increased hospital costs, and controlling for endogeneity lead to higher attributable cost estimates. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Molecular Analysis of Vancomycin-Resistant Enterococci Isolated from Regional Hospitals in Trinidad and Tobago

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Patrick E. Akpaka

2016-01-01

Full Text Available Geographic spread of vancomycin-resistant enterococci (VRE clones in cities, countries, or even continents has been identified by molecular techniques. This study aimed at characterizing virulent genes and determining genetic relatedness of 45 VRE isolates from Trinidad and Tobago using molecular tools, including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE, and Random Amplification Polymorphic DNA (RAPD. The majority (84% of the isolates were Enterococcus faecium possessing vanA gene while the rest (16% were Enterococcus faecalis possessing vanB. The esp gene was found in all 45 VRE isolates while hyl genes were found only in E. faecium species. The E. faecium species expressed five distinct PFGE patterns. The predominant clones with similar or common patterns belonged to clones one and three, and each had 11 (29% of the VRE isolates. Plasmid content was identified in representative isolates from each clonal group. By contrast, the E. faecalis species had one PFGE pattern suggesting the presence of an occult and limited clonal spread. The emergence of VRE in the country seems to be related to intra/interhospital dissemination of an epidemic clone carrying the vanA element. Therefore, infection control measures will be warranted to prevent any potential outbreak and spread of VRE in the country.

Rapid and easy detection of low-level resistance to vancomycin in methicillin-resistant Staphylococcus aureus by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

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Asakura, Kota; Azechi, Takuya; Sasano, Hiroshi; Matsui, Hidehito; Hanaki, Hideaki; Miyazaki, Motoyasu; Takata, Tohru; Sekine, Miwa; Takaku, Tomoiku; Ochiai, Tomonori; Komatsu, Norio; Shibayama, Keigo; Katayama, Yuki; Yahara, Koji

2018-01-01

Vancomycin-intermediately resistant Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are associated with treatment failure. hVISA contains only a subpopulation of cells with increased minimal inhibitory concentrations, and its detection is problematic because it is classified as vancomycin-susceptible by standard susceptibility testing and the gold-standard method for its detection is impractical in clinical microbiology laboratories. Recently, a research group developed a machine-learning classifier to distinguish VISA and hVISA from vancomycin-susceptible S. aureus (VSSA) according to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) data. Nonetheless, the sensitivity of hVISA classification was found to be 76%, and the program was not completely automated with a graphical user interface. Here, we developed a more accurate machine-learning classifier for discrimination of hVISA from VSSA and VISA among MRSA isolates in Japanese hospitals by means of MALDI-TOF MS data. The classifier showed 99% sensitivity of hVISA classification. Furthermore, we clarified the procedures for preparing samples and obtaining MALDI-TOF MS data and developed all-in-one software, hVISA Classifier, with a graphical user interface that automates the classification and is easy for medical workers to use; it is publicly available at https://github.com/bioprojects/hVISAclassifier. This system is useful and practical for screening MRSA isolates for the hVISA phenotype in clinical microbiology laboratories and thus should improve treatment of MRSA infections.

Cost Comparison of Linezolid Versus Vancomycin for Treatment of Complicated Skin and Skin-Structure Infection Caused by Methicillin-Resistant Staphylococcus aureus in Quebec

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Martine Pettigrew

2012-01-01

Full Text Available BACKGROUND: In Canada, complicated skin and skin-structure infection (cSSSI caused by methicillin-resistant Staphylococcus aureus (MRSA is usually treated with antibiotics in hospital, with a follow-up course at home for stable patients. The cost implications of using intravenous and oral linezolid instead of intravenous vancomycin in Canadian clinical practice have not been examined.

The Relationship Between Vancomycin Trough Concentrations and AUC/MIC Ratios in Pediatric Patients: A Qualitative Systematic Review.

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Tkachuk, Stacey; Collins, Kyle; Ensom, Mary H H

2018-04-01

In adults, the area under the concentration-time curve (AUC) divided by the minimum inhibitory concentration (MIC) is associated with better clinical and bacteriological response to vancomycin in patients with methicillin-resistant Staphylococcus aureus who achieve target AUC/MIC ≥ 400. This target is often extrapolated to pediatric patients despite the lack of similar evidence. The impracticalities of calculating the AUC in practice means vancomycin trough concentrations are used to predict the AUC/MIC. This review aimed to determine the relationship between vancomycin trough concentrations and AUC/MIC in pediatric patients. We searched the MEDLINE and Embase databases, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials using the medical subject heading (MeSH) terms vancomycin and AUC and pediatric* or paediatric*. Articles were included if they were published in English and reported a relationship between vancomycin trough concentrations and AUC/MIC. Of 122 articles retrieved, 11 met the inclusion criteria. One trial reported a relationship between vancomycin trough concentrations, AUC/MIC, and clinical outcomes but was likely underpowered. Five studies found troughs 6-10 mg/l were sufficient to attain an AUC/MIC > 400 in most general hospitalized pediatric patients. One study in patients undergoing cardiothoracic surgery found a trough of 18.4 mg/l achieved an AUC/MIC > 400. Two oncology studies reported troughs ≥ 15 mg/l likely attained an AUC/MIC ≥ 400. In critical care patients: one study found a trough of 9 mg/l did not attain the AUC/MIC target; another found 7 mg/l corresponded to an AUC/MIC of 400. Potential vancomycin targets varied based on the population studied but, for general hospitalized pediatric patients, troughs of 6-10 mg/l are likely sufficient to achieve AUC/MIC ≥ 400. For MIC ≥ 2 mg/l, higher troughs are likely necessary to achieve an AUC/MIC ≥ 400. More

Antimicrobial susceptibility and glycopeptide-resistance of enterococci in vegetables

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Ida Torre

2010-03-01

Full Text Available

Background: Vancomycin-resistant enterococci (VRE, often responsible for nosocomial infections, have frequently been isolated from animal and vegetable foods. In our study we evaluated the antibiotic susceptibility of enterococci isolated from eight types of vegetables randomly selected from grocery stores in Naples.

Methods: From July to November 2008, we analyzed 150 samples: the bacteria were isolated with standardized methods and antibiotic susceptibility was determined using the disc diffusion method. The resistance to vancomycin versus other antibiotics was assessed by the Kappa test.

Results: 70% of the samples, mainly parsley (96.2%, showed enterococci. Of these, 59.1% belonged to the species Enterococcus faecium. Strains resistant to vancomycin and teicoplanin were isolated respectively in 47.6% and 49.5% of the samples: the first one mainly in curly endive (72.7% and the second one in parsley (76.9%. Almost all the isolated strains showed resistance to methicillin (89%, kanamycin (82% and cephalothin (68%. The Kappa test showed statistically significant associations between resistance to vancomycin and resistance to teicoplanin, erythromycin, methicillin, tetracycline and chloramphenicol.

Conclusions: Because of the possible involvement of food in the transmission of resistant micro-organisms to human intestinal microbiota, our data may provide the basis for future studies.

Comparative effectiveness of nafcillin or cefazolin versus vancomycin in methicillin-susceptible Staphylococcus aureus bacteremia

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McGregor Jessina C

2011-10-01

Full Text Available Abstract Background The high prevalence of methicillin-resistant S. aureus (MRSA has led clinicians to select antibiotics that have coverage against MRSA, usually vancomycin, for empiric therapy for suspected staphylococcal infections. Clinicians often continue vancomycin started empirically even when methicillin-susceptible S. aureus (MSSA strains are identified by culture. However, vancomycin has been associated with poor outcomes such as nephrotoxicity, persistent bacteremia and treatment failure. The objective of this study was to compare the effectiveness of vancomycin versus the beta-lactam antibiotics nafcillin and cefazolin among patients with MSSA bacteremia. The outcome of interest for this study was 30-day in-hospital mortality. Methods This retrospective cohort study included all adult in-patients admitted to a tertiary-care facility between January 1, 2003 and June 30, 2007 who had a positive blood culture for MSSA and received nafcillin, cefazolin or vancomycin. Cox proportional hazard models were used to assess independent mortality hazards comparing nafcillin or cefazolin versus vancomycin. Similar methods were used to estimate the survival benefits of switching from vancomycin to nafcillin or cefazolin versus leaving patients on vancomycin. Each model included statistical adjustment using propensity scores which contained variables associated with an increased propensity to receive vancomycin. Results 267 patients were included; 14% (38/267 received nafcillin or cefazolin, 51% (135/267 received both vancomycin and either nafcillin or cefazolin, and 35% (94/267 received vancomycin. Thirty (11% died within 30 days. Those receiving nafcillin or cefazolin had 79% lower mortality hazards compared with those who received vancomycin alone (adjusted hazard ratio (HR: 0.21; 95% confidence interval (CI: 0.09, 0.47. Among the 122 patients who initially received vancomycin empirically, those who were switched to nafcillin or cefazolin (66

AUC/MIC Pharmacodynamic Target Is Not a Good Predictor of Vancomycin Efficacy in Methicillin-Resistant Staphylococcus aureus Experimental Endocarditis.

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Castañeda, Ximena; García-de-la-Mària, Cristina; Gasch, Oriol; Pericas, Juan M; Armero, Yolanda; Soy, Dolors; García-González, Javier; Falces, Carlos; Ninot, Salvador; Almela, Manel; Ambrosioni, Juan; Quintana, Eduardo; Vidal, Barbara; Fuster, David; Llopis, Jaume; Soto, Sara; Moreno, Asuncion; Marco, Francesc; Miró, Jose M

2017-06-01

The aim of this in vivo study was to compare the efficacy of vancomycin at standard doses (VAN-SD) to that of VAN at adjusted doses (VAN-AD) in achieving a VAN area under the curve/MIC ratio (AUC/MIC) of ≥400 against three methicillin-resistant Staphylococcus aureus (MRSA) strains with different microdilution VAN MICs in an experimental endocarditis model. The valve vegetation bacterial counts after 48 h of VAN therapy were compared, and no differences were observed between the two treatment groups for any of the three strains tested. Overall, for VAN-SD and VAN-AD, the rates of sterile vegetations were 15/45 (33.3%) and 21/49 (42.8%) ( P = 0.343), while the medians (interquartile ranges [IQRs]) for log 10 CFU/g of vegetation were 2 (0 to 6.9) and 2 (0 to 4.5) ( P = 0.384), respectively. In conclusion, this VAN AUC/MIC pharmacodynamic target was not a good predictor of vancomycin efficacy in MRSA experimental endocarditis. Copyright © 2017 American Society for Microbiology.

DRESS with delayed onset acute interstitial nephritis and profound refractory eosinophilia secondary to Vancomycin

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O'Meara Paloma

2011-10-01

Full Text Available Abstract Background Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS is a relatively rare clinical entity; even more so in response to vancomycin. Methods Case report. Results We present a severe case of vancomycin-induced DRESS syndrome, which on presentation included only skin, hematological and mild liver involvement. The patient further developed severe acute interstitial nephritis, eosinophilic pneumonitis, central nervous system (CNS involvement and worsening hematological abnormalities despite immediate discontinuation of vancomycin and parenteral corticosteroids. High-dose corticosteroids for a prolonged period were necessary and tapering of steroids a challenge due to rebound-eosinophilia and skin involvement. Conclusion Patients with DRESS who are relatively resistant to corticosteroids with delayed onset of certain organ involvement should be treated with a more prolonged corticosteroid tapering schedule. Vancomycin is increasingly being recognized as a culprit agent in this syndrome.

Biofilm-Forming Staphylococcus epidermidis Expressing Vancomycin Resistance Early after Adhesion to a Metal Surface

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Toshiyuki Sakimura

2015-01-01

Full Text Available We investigated biofilm formation and time of vancomycin (VCM resistance expression after adhesion to a metal surface in Staphylococcus epidermidis. Biofilm-forming Staphylococcus epidermidis with a VCM MIC of 1 μg/mL was used. The bacteria were made to adhere to a stainless steel washer and treated with VCM at different times and concentrations. VCM was administered 0, 2, 4, and 8 hours after adhesion. The amount of biofilm formed was evaluated based on the biofilm coverage rates (BCRs before and after VCM administration, bacterial viability in biofilm was visually observed using the fluorescence staining method, and the viable bacterial count in biofilm was measured. The VCM concentration required to decrease BCR significantly compared with that of VCM-untreated bacteria was 4 μg/mL, even in the 0 hr group. In the 4 and 8 hr groups, VCM could not inhibit biofilm growth even at 1,024 μg/mL. In the 8 hr group, viable bacteria remained in biofilm at a count of 104 CFU even at a high VCM concentration (1,024 μg/mL. It was suggested that biofilm-forming Staphylococcus epidermidis expresses resistance to VCM early after adhesion to a metal surface. Resistance increased over time after adhesion as the biofilm formed, and strong resistance was expressed 4–8 hours after adhesion.

Vancomycin intoxication in a patient with inappropriate antidiuretic hormone syndrome and diarrhea

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Patricia Hidalgo-Collazos

2015-07-01

Full Text Available Vancomycin is an antibiotic used for infections by gram-positive bacteria with a two-compartment pharmacokinetic model. Its monitoring has an established therapeutic range (10-20 mg/L to prevent nephrotoxicity and ototoxicity due to supratherapeutic levels, and inefficiency and development of resistance by subtherapeutic levels. Nephrotoxicity for vancomycin monotherapy at standard doses according to pathogen and typical regimens (usual dose: 15-20 mg/kg/12 h is rare and usually reversible. Moreover, monitoring plasma concentrations allows to achieve concentrations within therapeutic range to allow safe and effective drug use. The renal hypoperfusion can cause pre-renal damage, resulting in elevated levels of serum creatinine, resulting in decreased antibiotic elimination and nephrotoxicity. We report a case of unexpected vancomycin nephrotoxicity in a patient with syndrome Inappropriate antidiuretic hormone secretion associated paraneoplastic

Characterization of Vancomycin Reactions and Linezolid Utilization in the Pediatric Population.

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Lin, Samantha K; Mulieri, Kevin M; Ishmael, Faoud T

Red man syndrome (RMS) occurs because of non-IgE-mediated histamine release. Unlike vancomycin allergy, which necessitates the use of an alternative drug (often linezolid), RMS does not typically preclude further vancomycin use. Care should be taken to differentiate these reaction types from one another to prevent unnecessary vancomycin avoidance. To characterize vancomycin reaction types in our population, and to determine whether having a reaction consistent with RMS is associated with otherwise unexplained vancomycin avoidance and linezolid use. We retrospectively reviewed charts for children with documented vancomycin reactions. We classified the in-hospital reactions via an objective analysis and estimated the prevalence of different reaction types. We then identified children who received linezolid over 3 years, and investigated reasons for linezolid use instead of vancomycin. Of the 78 in-hospital reactions we characterized, 72 (92%) were objectively consistent with RMS, 5 we could not objectively classify (2 most likely RMS, 3 more suspicious for possible IgE-mediated allergy), and 1 was a non-RMS/non-IgE reaction. Of 60 children who received linezolid, 19 had previous reactions consistent with RMS, which should not preclude further vancomycin. Nevertheless, only 7 of 19 (37%) had a clear explanation for receiving linezolid instead of vancomycin compared with 32 of 39 (82%) children without previous vancomycin reactions (P linezolid utilization. We propose that this may be related to how reactions appear in the electronic medical record. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Clinical outcomes of linezolid and vancomycin in patients with nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus stratified by baseline renal function: a retrospective, cohort analysis.

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Liu, Ping; Capitano, Blair; Stein, Amy; El-Solh, Ali A

2017-05-22

The primary objective of this study is to assess whether baseline renal function impacts treatment outcomes of linezolid and vancomycin (with a dose-optimized regimen) for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. We conducted a retrospective cohort analysis of data generated from a prospective, randomized, controlled clinical trial (NCT 00084266). The analysis included 405 patients with culture-proven MRSA pneumonia. Baseline renal function was stratified based on creatinine clearance. Clinical and microbiological success rates and presence of nephrotoxicity were assessed at the end of treatment (EOT) and end of study (EOS). Multivariate logistic regression analyses of baseline patient characteristics, including treatment, were performed to identify independent predictors of efficacy. Vancomycin concentrations were analyzed using a nonlinear mixed-effects modeling approach. The relationships between vancomycin exposures, pharmacokinetic-pharmacodynamic index (trough concentration, area under the curve over a 24-h interval [AUC 0-24 ], and AUC 0-24 /MIC) and efficacy/nephrotoxicity were assessed in MRSA pneumonia patients using univariate logistic regression or Cox proportional hazards regression analysis approach. After controlling for use of vasoactive agents, choice of antibiotic therapy and bacteremia, baseline renal function was not correlated with clinical and microbiological successes in MRSA pneumonia at either end of treatment or at end of study for both treatment groups. No positive association was identified between vancomycin exposures and efficacy in these patients. Higher vancomycin exposures were correlated with an increased risk of nephrotoxicity (e.g., hazards ratio [95% confidence interval] for a 5 μg/ml increase in trough concentration: 1.42 [1.10, 1.82]). In non-dialysis patients, baseline renal function did not impact the differences in efficacy or nephrotoxicity with treatment of linezolid versus vancomycin in MRSA

Synthesis and biodistribution of 99mTc-Vancomycin in a model of bacterial infection

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Roohi, S.; Mushtaq, A.; Malik, S.A.

2005-01-01

Vancomycin Hydrochloride is an antibiotic produced by the growth of certain strains of Streptomyces orientalis. As vancomycin hydrochloride is poorly absorbed after oral administration; it is given intravenously for therapy of systemic infections. Vancomycin was labeled with technetium-99m pertechnetate using SnCl 2 . 2H 2 O as reducing agent. The labeling efficiency depends on ligand/reductant ratio, pH, and volume of reaction mixture. Radiochemical purity and stability of 99m Tc-Vancomycin was determined by thin layer chromatography. Biodistribution studies of 99m Tc-Vancomycin were performed in a model of bacterial infection in Sprague-Dawley rats. A significantly higher accumulation of 99m Tc-Vancomycin was seen at sites of S. aureus infected animals. Whereas uptake of 99m Tc-Vancomycin in turpentine inflamed rats were quite low. (orig.)

High-throughput determination of vancomycin in human plasma by a cost-effective system of two-dimensional liquid chromatography.

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Sheng, Yanghao; Zhou, Boting

2017-05-26

Therapeutic drug monitoring (TDM) is one of the most important services of clinical laboratories. Two main techniques are commonly used: the immunoassay and chromatography method. We have developed a cost-effective system of two-dimensional liquid chromatography with ultraviolet detection (2D-LC-UV) for high-throughput determination of vancomycin in human plasma that combines the automation and low start-up costs of the immunoassay with the high selectivity and sensitivity of the liquid chromatography coupled with mass spectrometric detection without incurring their disadvantages, achieving high cost-effectiveness. This 2D-LC system offers a large volume injection to provide sufficient sensitivity and uses simulated gradient peak compression technology to control peak broadening and to improve peak shape. A middle column was added to reduce the analysis cycle time and make it suitable for high-throughput routine clinical assays. The analysis cycle time was 4min and the peak width was 0.8min. Compared with other chromatographic methods that have been developed, the analysis cycle time and peak width for vancomycin was reduced significantly. The lower limit of quantification was 0.20μg/mL for vancomycin, which is the same as certain LC-MS/MS methods that have been recently developed and validated. The method is rapid, automated, and low-cost and has high selectivity and sensitivity for the quantification of vancomycin in human plasma, thus making it well-suited for use in hospital clinical laboratories. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous determination of vancomycin and ceftazidime in cerebrospinal fluid in craniotomy patients by high-performance liquid chromatography.

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Ye, Guangming; Cai, Xuejian; Wang, Biao; Zhou, Zhongxian; Yu, Xiaohua; Wang, Weibin; Zhang, Jiandong; Wang, Yuhai; Dong, Jierong; Jiang, Yunyun

2008-11-04

A simple, accurate and rapid method for simultaneous analysis of vancomycin and ceftazidime in cerebrospinal fluid (CSF), utilizing high-performance liquid chromatography (HPLC), has been developed and thoroughly validated to satisfy strict FDA guidelines for bioanalytical methods. Protein precipitation was used as the sample pretreatment method. In order to increase the accuracy, tinidazole was chosen as the internal standard. Separation was achieved on a Diamonsil C18 column (200 mm x 4.6mm I.D., 5 microm) using a mobile phase composed of acetonitrile and acetate buffer (pH 3.5) (8:92, v/v) at room temperature (25 degrees C), and the detection wavelength was 240 nm. All the validation data, such as accuracy, precision, and inter-day repeatability, were within the required limits. The method was applied to determine vancomycin and ceftazidime concentrations in CSF in five craniotomy patients.

Misidentification of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Tripoli, Libya

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Ahmed, Mohamed O.; Abuzweda, Abdulbaset R.; Alghazali, Mohamed H.; Elramalli, Asma K.; Amri, Samira G.; Aghila, Ezzeddin Sh.; Abouzeed, Yousef M.

2010-01-01

Background Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial (hospital-acquired) pathogen of exceptional concern. It is responsible for life-threatening infections in both the hospital and the community. Aims To determine the frequency of MRSA misidentification in hospitals in Tripoli, Libya using current testing methods. Methods One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 Staph System and retested for resistance to methicillin using the cefoxitin disk diffusion susceptibility test and PBP2a. D-tests and vancomycin E-tests (Van-E-tests) were also performed for vancomycin-resistant isolates. Results Of the 170 isolates examined, 86 (51%) were confirmed as MRSA (i.e. 49% were misidentified as MRSA). Fifteen (17%) of the confirmed MRSA strains exhibited inducible clindamycin resistance. Of the 86 confirmed MRSA isolates, 13 (15%) were resistant to mupirocin, 53 (62%) were resistant to ciprofloxacin, 41 (48%) were resistant to trimethoprim-sulfamethoxazole, and none were resistant to linezolid. Although disc-diffusion testing indicated that 23 (27%) of the isolates were resistant to vancomycin, none of the isolates were vancomycin-resistant by Van-E-test. Conclusions Misidentification of nosocomial S. aureus as MRSA is a serious problem in Libyan hospitals. There is an urgent need for the proper training of microbiology laboratory technicians in standard antimicrobial susceptibility procedures and the implementation of quality control programs in microbiology laboratories of Libyan hospitals. PMID:21483574

Protective Effects of Cilastatin against Vancomycin-Induced Nephrotoxicity

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Blanca Humanes

2015-01-01

Full Text Available Vancomycin is a very effective antibiotic for treatment of severe infections. However, its use in clinical practice is limited by nephrotoxicity. Cilastatin is a dehydropeptidase I inhibitor that acts on the brush border membrane of the proximal tubule to prevent accumulation of imipenem and toxicity. The aim of this study was to investigate the potential protective effect of cilastatin on vancomycin-induced apoptosis and toxicity in cultured renal proximal tubular epithelial cells (RPTECs. Porcine RPTECs were cultured in the presence of vancomycin with and without cilastatin. Vancomycin induced dose-dependent apoptosis in cultured RPTECs, with DNA fragmentation, cell detachment, and a significant decrease in mitochondrial activity. Cilastatin prevented apoptotic events and diminished the antiproliferative effect and severe morphological changes induced by vancomycin. Cilastatin also improved the long-term recovery and survival of RPTECs exposed to vancomycin and partially attenuated vancomycin uptake by RPTECs. On the other hand, cilastatin had no effects on vancomycin-induced necrosis or the bactericidal effect of the antibiotic. This study indicates that cilastatin protects against vancomycin-induced proximal tubule apoptosis and increases cell viability, without compromising the antimicrobial effect of vancomycin. The beneficial effect could be attributed, at least in part, to decreased accumulation of vancomycin in RPTECs.

Retrospective Analysis of Clinical and Cost Outcomes Associated with Methicillin-Resistant Staphylococcus aureus Complicated Skin and Skin Structure Infections Treated with Daptomycin, Vancomycin, or Linezolid

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Bradley M. Wright

2011-01-01

Full Text Available Objective. The objective of this analysis was to compare clinical and cost outcomes associated with patients who had suspected or documented methicillin-resistant Staphylococcus aureus (MRSA infections treated with daptomycin, vancomycin, or linezolid in complicated skin and skin structure infections (cSSSIs. Design. This was a retrospective analysis conducted from February to June of 2007. Appropriate data was collected, collated, and subsequently evaluated with the purpose of quantifying length of stay, antibiotic therapy duration, clinical cure rates, adverse drug events, and cost of hospitalization. Results. All 82 patients included in the analysis experienced clinical cure. The duration of antibiotic therapy was similar among the three groups yet the length of hospitalization was slightly shorter in the daptomycin group. Conclusions. The incidence of resistant staphylococcal infections is increasing; therefore, judicious use of MRSA active agents is paramount. Future studies are necessary to determine if MRSA treatment options can be stratified based on the severity of the infectious process.

Nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus treated with linezolid or vancomycin: A secondary economic analysis of resource use from a Spanish perspective.

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Rello, J; Nieto, M; Solé-Violán, J; Wan, Y; Gao, X; Solem, C T; De Salas-Cansado, M; Mesa, F; Charbonneau, C; Chastre, J

2016-11-01

Adopting a unique Spanish perspective, this study aims to assess healthcare resource utilization (HCRU) and the costs of treating nosocomial pneumonia (NP) produced by methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized adults using linezolid or vancomycin. An evaluation is also made of the renal failure rate and related economic outcomes between study groups. An economic post hoc evaluation of a randomized, double-blind, multicenter phase 4 study was carried out. Nosocomial pneumonia due to MRSA in hospitalized adults. The modified intent to treat (mITT) population comprised 224 linezolid- and 224 vancomycin-treated patients. Costs and HCRU were evaluated between patients administered either linezolid or vancomycin, and between patients who developed renal failure and those who did not. Analysis of HCRU outcomes and costs. Total costs were similar between the linezolid- (€17,782±€9,615) and vancomycin-treated patients (€17,423±€9,460) (P=.69). The renal failure rate was significantly lower in the linezolid-treated patients (4% vs. 15%; Prenal failure (€19,626±€10,840 vs. €17,388±€9,369; P=.14). Among the patients who developed renal failure, HCRU (days on mechanical ventilation: 13.2±10.7 vs. 7.6±3.6 days; P=.21; ICU stay: 14.4±10.5 vs. 9.9±6.6 days; P=.30; hospital stay: 19.5±9.5 vs. 16.1±11.0 days; P=.26) and cost (€17,219±€8,792 vs. €20,263±€11,350; P=.51) tended to be lower in the linezolid- vs. vancomycin-treated patients. There were no statistically significant differences in costs per patient-day between cohorts after correcting for mortality (€1000 vs. €1,010; P=.98). From a Spanish perspective, there were no statistically significant differences in total costs between the linezolid and vancomycin pneumonia cohorts. The drug cost corresponding to linezolid was partially offset by fewer renal failure adverse events. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Internalization of Staphylococcus aureus in Lymphocytes Induces Oxidative Stress and DNA Fragmentation: Possible Ameliorative Role of Nanoconjugated Vancomycin

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Subhankari Prasad Chakraborty

2011-01-01

Full Text Available Staphylococcus aureus is the most frequently isolated pathogen causing bloodstream infections, skin and soft tissue infections and pneumonia. Lymphocyte is an important immune cell. The aim of the present paper was to test the ameliorative role of nanoconjugated vancomycin against Vancomycin-sensitive Staphylococcus aureus (VSSA and vancomycin-resistant Staphylococcus aureus (VRSA infection-induced oxidative stress in lymphocytes. VSSA and VRSA infections were developed in Swiss mice by intraperitoneal injection of 5×106 CFU/mL bacterial solutions. Nanoconjugated vancomycin was adminstrated to VSSA- and VRSA-infected mice at its effective dose for 10 days. Vancomycin was adminstrated to VSSA- and VRSA-infected mice at a similar dose, respectively, for 10 days. Vancomycin and nanoconjugated vancomycin were adminstrated to normal mice at their effective doses for 10 days. The result of this study reveals that in vivo VSSA and VRSA infection significantly increases the level of lipid peroxidation, protein oxidation, oxidized glutathione level, nitrite generation, nitrite release, and DNA damage and decreases the level of reduced glutathione, antioxidant enzyme status, and glutathione-dependent enzymes as compared to control group, which were increased or decreased significantly near to normal in nanoconjugated vancomycin-treated group. These findings suggest the potential use and beneficial role of nanoconjugated vancomycin against VSSA and VRSA infection-induced oxidative stress in lymphocytes.

Ultra high performance liquid chromatography-tandem mass spectrometry vs. commercial immunoassay for determination of vancomycin plasma concentration in children. Possible implications for everyday clinical practice.

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Barco, Sebastiano; Castagnola, Elio; Gennai, Iulian; Barbagallo, Laura; Loy, Anna; Tripodi, Gino; Cangemi, Giuliana

2016-10-01

Vancomycin therapeutic drug monitoring (TDM) is necessary for effective and safetherapy. The aim of the this paper was to develop a specific and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for vancomycin quantification starting from low plasma volumes to be applied for the routine TDM in children. Samples from children receiving intravenous vancomycin were analysed using a TSQ Quantum Access MAX Triple Quadrupole system coupled with an Accela 1250 UHPLC system after a rapid protein precipitation. Gradient separation chromatography was carried out using a Hypersil GOLD aQ C18 column (50 × 2.1 mm, particle size 1.9 μm). Method performance was validated following international guidelines. UHPLC-MS/MS allowed a rapid and specific quantification of vancomycin over the range 0.1-128 μg/mL from 50 μL of plasma with high reproducibility and accuracy in the absence of matrix effect. The comparison with the commercial immunoassay performed on 138 samples demonstrated the presence of a proportional bias. The concentrations of vancomycin measured with immunoassay were found to be 4.5% (95% CI: 1.3-7.7) higher than those determined with UHPLC-MS/MS. Importantly, a clinical discordance was found in about 10% of samples analysed. This new UHPLC-MS/MS method is accurate and specific for the measurement of vancomycin starting from small (50 μL) plasma volumes. The use of UHPLC-MS/MS is recommended to prevent a misclassification of therapeutic or toxic vancomycin levels in paediatrics.

Vancomycin

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... is in a class of medications called glycopeptide antibiotics. It works by killling bacteria in the intestines. Vancomycin will ... part of the body when taken by mouth. Antibiotics will not work for colds, flu, or other viral infections.

Vancomycin treatment of infective endocarditis is linked with recently acquired obesity.

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Franck Thuny

Full Text Available BACKGROUND: Gut microbiota play a major role in digestion and energy conversion of nutrients. Antibiotics, such as avoparcin (a vancomycin analogue, and probiotics, such as Lactobacillus species, have been used to increase weight in farm animals. We tested the effect of antibiotics given for infective endocarditis (IE on weight gain (WG. METHODOLOGY/PRINCIPAL FINDINGS: Forty-eight adults with a definite diagnosis of bacterial IE (antibiotic group were compared with forty-eight age-matched controls without IE. Their body mass index (BMI was collected at one month before the first symptoms and one year after hospital discharge. The BMI increased significantly and strongly in vancomycin-plus-gentamycin-treated patients (mean [+/-SE] kg/m(2, +2.3 [0.9], p = 0.03, but not in controls or in patients treated with other antibiotics. Seventeen patients had a BMI increase of >or=10%, and five of the antibiotic group developed obesity. The treatment by vancomycin-plus-gentamycin was an independent predictor of BMI increase of >or=10% (adjusted OR, 6.7; 95% CI, 1.37-33.0; p = 0.02, but not treatment with other antibiotics. Weight gain was particularly high in male patients older than 65 who did not undergo cardiac surgery. Indeed, all three vancomycin-treated patients with these characteristics developed obesity. CONCLUSIONS/SIGNIFICANCE: A major and significant weight gain can occur after a six-week intravenous treatment by vancomycin plus gentamycin for IE with a risk of obesity, especially in males older than 65 who have not undergone surgery. We speculate on the role of the gut colonization by Lactobacillus sp, a microorganism intrinsically resistant to vancomycin, used as a growth promoter in animals, and found at a high concentration in the feces of obese patients. Thus, nutritional programs and weight follow-up should be utilized in patients under such treatment.

AUC versus peak-trough dosing of vancomycin: applying new pharmacokinetic paradigms to an old drug.

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Brown, Daniel L; Lalla, Christina D; Masselink, Andrew J

2013-08-01

To compare and contrast the pharmacokinetic/pharmacodynamic foundations of traditional "peak-trough" vancomycin dosing methods versus newer "area under the curve" (AUC) strategies. To propose a new AUC-based dosing chart for empirically determining an initial vancomycin dosing regimen designed to achieve a desired AUC24 using the minimum inhibitory concentration (MIC), creatinine clearance (CrCl), and vancomycin clearance (ClVanco). Peak-trough vancomycin dosing is designed to achieve a Cpeak of 20-40 mg/L and a Ctrough of 10-15 or 15-20 mg/L, depending on the severity of the infection and the nature of the pathogen. New treatment guidelines for vancomycin suggest that therapy should achieve an AUC24/MIC of ≥400. AUC-based vancomycin dosing derives the daily dose from ClVanco, MIC, and the desired AUC24/MIC, without consideration of the patient's weight. A vancomycin dosing chart is proposed that estimates ClVanco using the following formula developed by Matzke et al: ClVanco in L/h = [(CrClmL/min × 0.689) + 3.66] × 0.06, which simplifies to (CrClmL/min × 0.41) + 0.22. Two levels of dosing are included-high dose (Ctrough: 15-20 mg/L) and moderate dose (Ctrough: 10-15 mg/L). Although the chart has not been validated clinically, it represents the product of standard dosing equations that are used to determine a starting dosing regimen based on well-established vancomycin pharmacokinetic parameters. An understanding of pharmacokinetic and pharmacodynamic principles, including the relevance of AUC in relation to MIC, enables clinicians to make the best use of vancomycin dosing options. The proposed dosing chart is pharmacokinetically valid but has yet to be applied clinically. It provides a foundation for further study of how clinicians can determine an optimal AUC-based starting vancomycin dosing regimen without having to derive ClVanco or AUC24.

DETERMINATION OF THE SPECTRUM OF ANTIBIOTIC RESISTANCE GENES HAVE PHENOTYPIC RESISTANT STRAINS OF PARIETAL INTESTINAL MICROBIOTA IN RATS BY RT-PCR

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Bukina Y.V.

2016-06-01

Full Text Available Introduction. The problem of formation of bacterial resistance to glycopeptides and beta-lactam antibiotics (cephalosporins and carbapenems are used worldwide for the treatment of severe community acquired and nosocomial infections, especially caused by polymicrobial flora has become global and is a major factor limiting the effectiveness of antibiotic therapy. In this regard, the study of genetic microbial resistance determinants allows not only to carry out an effective antibiotic therapy, but also to identify two main processes leading to the development of epidemiologically significant events: the introduction of the agent in the risk population from the outside and in situ pathogen (spontaneous genetic drift targeted restructuring of the population. Therefore, the aim of our study was to investigate the resistance genes to carbapenems, cephalosporins, glycopeptides have clinically important phenotype of resistant strains of microorganisms families Enterobacteriaceae, Pseudomonadaceae, Bacteroidaceae, Enterococcaceae, Peptostreptococcaceae. Materials and methods. As a material for PCR studies 712 phenotypically resistant strains of microorganisms isolated from 80 rats "Wistar" line in microbiological study microflora of the wall were used. During the investigation 474 isolates of bacteria of the family Enterobacteriaceae, 39 - Pseudomonadaceae, 71 - Bacteroidaceae, 96 - Enterococcaceae, 32 - Peptostreptococcaceae were studied. Isolation of DNA from bacteria in the study was performed using reagents "DNA-Express" ("Litekh", Russia. For the detection of resistance genes by PCR in real time (RT-PCR reagent kits "FLUOROPOL-RV" ("Litekh", Russia were used. During the experiment, the VIM genes, OXA-48, NDM, KPC, responsible for the resistance of microorganisms to carbapenems, CTX-M - resistance to cephalosporins, as well as genes Van A and van B, the development of resistance to glycopeptides (vancomycin and teicoplanin were determined. Analysis

Vancomycin gene selection in the microbiome of urban Rattus norvegicus from hospital environment

DEFF Research Database (Denmark)

Arn Hansen, Thomas; Joshi, Tejal; Larsen, Anders Rhod

2016-01-01

Widespread use of antibiotics has resulted in selection pressure on genes that make bacteria non-responsive to antibiotics. These antibiotic-resistant bacteria are currently a major threat to global health. There are various possibilities for the transfer of antibiotic resistance genes. It has be....... norvegicus microbiome, potentially driven by the outflow of antibiotics and antibiotic-resistant bacteria into the wastewater systems. Carriage of vancomycin resistance may suggest that R. norvegicus is acting as a reservoir for possible transmission to the human population....

Presence of the vancomycin resistance gene cluster vanC1, vanXYc, and vanT in Enterococcus casseliflavus.

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Hölzel, Christina; Bauer, Johann; Stegherr, Eva-Maria; Schwaiger, Karin

2014-04-01

The three chromosomally located clustered genes vanC1, vanXYc, and vanT confer intrinsic resistance to vancomycin and are used for species identification of Enterococcus gallinarum. In this study, 28 strains belonging to the E. gallinarum/casseliflavus group isolated from cloacal swabs from laying hens were screened for the presence of vanC1. As confirmed by species-specific multiplex PCR, 11 vanC1-positive strains were identified as E. gallinarum. Surprisingly, one yellow pigmented strain, verified as E. casseliflavus by species-specific multiplex PCR, was also vanC1 positive; vanXYc and vanT were additionally detectable in this strain. To our knowledge, this is the first report of vanC1, vanXYc, and vanT in E. casseliflavus. The minimum inhibitory concentration of vancomycin was 4 mg/L. Real-time reverse transcription-PCR revealed that none of the clustered genes was expressed in this strain. Even if the genes seem not to be active, there is a certain risk that they will be transferred to other bacteria where they might be functionally expressed. Therefore, it may be advisable to expand the search for vanC1, vanXYc, and vanT from E. gallinarum to other (enterococcal) species. This study confirms that enterococci live up to their name as being reservoir bacteria and should therefore always be closely monitored.

Reduction in hospital-associated methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus with daily chlorhexidine gluconate bathing for medical inpatients.

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Lowe, Christopher F; Lloyd-Smith, Elisa; Sidhu, Baljinder; Ritchie, Gordon; Sharma, Azra; Jang, Willson; Wong, Anna; Bilawka, Jennifer; Richards, Danielle; Kind, Thomas; Puddicombe, David; Champagne, Sylvie; Leung, Victor; Romney, Marc G

2017-03-01

Daily bathing with chlorhexidine gluconate (CHG) is increasingly used in intensive care units to prevent hospital-associated infections, but limited evidence exists for noncritical care settings. A prospective crossover study was conducted on 4 medical inpatient units in an urban, academic Canadian hospital from May 1, 2014-August 10, 2015. Intervention units used CHG over a 7-month period, including a 1-month wash-in phase, while control units used nonmedicated soap and water bathing. Rates of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) colonization or infection were the primary end point. Hospital-associated S. aureus were investigated for CHG resistance with a qacA/B and smr polymerase chain reaction (PCR) and agar dilution. Compliance with daily CHG bathing was 58%. Hospital-associated MRSA and VRE was decreased by 55% (5.1 vs 11.4 cases per 10,000 inpatient days, P = .04) and 36% (23.2 vs 36.0 cases per 10,000 inpatient days, P = .03), respectively, compared with control cohorts. There was no significant difference in rates of hospital-associated Clostridium difficile. Chlorhexidine resistance testing identified 1 isolate with an elevated minimum inhibitory concentration (8 µg/mL), but it was PCR negative. This prospective pragmatic study to assess daily bathing for CHG on inpatient medical units was effective in reducing hospital-associated MRSA and VRE. A critical component of CHG bathing on medical units is sustained and appropriate application, which can be a challenge to accurately assess and needs to be considered before systematic implementation. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

ANTIBIOTIC RESISTANCE IN LACTIC ACID BACTERIA ISOLATED FROM FERMENTED DAIRY PRODUCTS AND BOZA

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Gamze Başbülbül

2015-06-01

Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.

Comparison of vancomycin and linezolid in patients with peripheral vascular disease and/or diabetes in an observational European study of complicated skin and soft-tissue infections due to methicillin-resistant Staphylococcus aureus.

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Eckmann, C; Nathwani, D; Lawson, W; Corman, S; Solem, C; Stephens, J; Macahilig, C; Li, J; Charbonneau, C; Baillon-Plot, N; Haider, S

2015-09-01

Suboptimal antibiotic penetration into soft tissues can occur in patients with poor circulation due to peripheral vascular disease (PVD) or diabetes. We conducted a real-world analysis of antibiotic treatment, hospital resource use and clinical outcomes in patients with PVD and/or diabetes receiving linezolid or vancomycin for the treatment of methicillin-resistant Staphylococcus aureus complicated skin and soft-tissue infections (MRSA cSSTIs) across Europe. This subgroup analysis evaluated data obtained from a retrospective, observational medical chart review study that captured patient data from 12 European countries. Data were obtained from the medical records of patients ≥ 18 years of age, hospitalized with an MRSA cSSTI between 1 July 2010 and 30 June 2011 and discharged alive by 31 July 2011. Hospital length of stay and length of treatment were compared between the treatment groups using inverse probability of treatment weights to adjust for clinical and demographic differences. A total of 485 patients had PVD or diabetes and received treatment with either vancomycin (n = 258) or linezolid (n = 227). After adjustment, patients treated with linezolid compared with vancomycin respectively had significantly shorter hospital stays (17.9 ± 13.6 vs. 22.6 ± 13.6 days; p linezolid and vancomycin groups, respectively (p linezolid compared with vancomycin. Copyright © 2015. Published by Elsevier Ltd.

Vancomycin Injection

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... is in a class of medications called glycopeptide antibiotics. It works by killing bacteria that cause infections.Antibiotics such as vancomycin injection will not work for colds, flu, or other viral infections. Taking ...

Typing of vancomycin-resistant enterococci with MALDI-TOF mass spectrometry in a nosocomial outbreak setting.

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Holzknecht, B J; Dargis, R; Pedersen, M; Pinholt, M; Christensen, J J

2018-03-23

To investigate the usefulness of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) typing as a first-line epidemiological tool in a nosocomial outbreak of vancomycin-resistant Enterococcus faecium (VREfm). Fifty-five VREfm isolates, previously characterized by whole-genome sequencing (WGS), were included and analysed by MALDI-TOF MS. To take peak reproducibility into account, ethanol/formic acid extraction and other steps of the protocol were conducted in triplicate. Twenty-seven spectra were generated per isolate, and spectra were visually inspected to determine discriminatory peaks. The presence or absence of these was recorded in a peak scheme. Nine discriminatory peaks were identified. A characteristic pattern of these could distinguish between the three major WGS groups: WGS I, WGS II and WGS III. Only one of 38 isolates belonging to WGS I, WGS II or WGS III was misclassified. However, ten of the 17 isolates not belonging to WGS I, II or III displayed peak patterns indistinguishable from those of the outbreak strain. Using visual inspection of spectra, MALDI-TOF MS typing proved to be useful in differentiating three VREfm outbreak clones from each other. However, as non-outbreak isolates could not be reliably differentiated from outbreak clones, the practical value of this typing method for VREfm outbreak management was limited in our setting. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Continuous infusion of vancomycin : Effective, efficient and safe

NARCIS (Netherlands)

Van Maarseveen, E.; Touw, D.; Bouma, A.; Van Zanten, A.

Aims: Vancomycin is an antibiotic which is used in (suspected or proven) bacteriaemia, peritonitis or osteomyelitis with grampositive micro-organisms. Currently in most Dutch hospitals vancomycin is administered as an intermittent infusion. As the killing of vancomycin is dependent of the AUC/MIC

Vancomycin analogues containing monosaccharides exhibit improved antibiotic activity: a combined one-pot enzymatic glycosylation and chemical diversification strategy.

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Thayer, Desiree A; Wong, Chi-Huey

2006-09-18

Many natural products contain carbohydrate moieties that contribute to their biological activity. Manipulation of the carbohydrate domain of natural products through multiple glycosylations to identify new derivatives with novel biological activities has been a difficult and impractical process. We report a practical one-pot enzymatic approach with regeneration of cosubstrates to synthesize analogues of vancomycin that contain an N-alkyl glucosamine, which exhibited marked improvement in antibiotic activity against a vancomycin-resistant strain of Enterococcus.

Uncommon vancomycin: induced side effects

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Rocha Jaime Luís Lopes

2002-01-01

Full Text Available Vancomycin has been used with increased frequency during the past 15 years and the most common toxicity with this drug is the "red man syndrome". Other adverse effects include neutropenia, fever, phlebitis, nephrotoxicity, ototoxicity, thrombocytopenia, interstitial nephritis, lacrimation, linear IgA bullous dermatosis, necrotizing cutaneous vasculitis and toxic epidermal necrolysis. Only two cases of vancomycin-induced Stevens-Johnson syndrome and one case of pancytopenia have been reported in the medical literature. The treatment for both situations is based on cessation of the vancomycin therapy; in cases of Stevens-Johnson syndrome, antihistamine and/or steroid agents can be used. This article reports a case of pancytopenia and a case of erythema major associated with neutropenia.

The effect of diabetes mellitus on outcomes of patients with nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus: data from a prospective double-blind clinical trial comparing treatment with linezolid versus vancomycin.

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Equils, Ozlem; da Costa, Christopher; Wible, Michele; Lipsky, Benjamin A

2016-09-06

The presence of diabetes mellitus increases the risk of several severe infections, but data on its effect on treatment outcomes in patients with nosocomial pneumonia (NP) caused by methicillin-resistant Staphylococcus aureus (MRSA) are limited. We retrospectively analyzed data from a double-blind, randomized, multi-center, international clinical trial of culture-confirmed MRSA NP that compared treatment with linezolid to vancomycin. Specifically, we evaluated the clinical and microbiologic outcomes of patients with and without diabetes in the modified intent to treat population at end-of-treatment (EOT) and end-of-study (EOS, 7-30 days post-EOT). Among 448 enrolled patients 183 (40.8 %) had diabetes mellitus, 87 (47.5 %) of whom received linezolid and 96 (52.5 %) vancomycin. Baseline demographic and clinical characteristics were similar for the two treatment groups. Clinical success rates at EOS were 57.6 % with linezolid and 39.3 % with vancomycin, while microbiological success rates were 58.9 % with linezolid and 41.1 % with vancomycin. Among diabetic patients, rates of mortality and study drug-related adverse effects were similar between the treatment groups. Overall day 28 mortality rates were higher among diabetic patients compared to non-diabetic patients (23.5 vs 14.7 %, respectively: RD = 8.8 %, 95 % CI [1.4, 16.3]). Among diabetic patients with MRSA NP, treatment with linezolid, compared to vancomycin, was associated with higher clinical and microbiologic success rates, and comparable adverse event rates. NCT00084266 .

Prophylactic intracameral vancomycin: efficacy in preventing endophthalmitis after cataract surgery

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Manash Kumar Goswami

2016-01-01

Full Text Available Background and objective: Post Operative endophthalmitis is rare but devastating complication in ocular surgery. The present study determined the efficacy of intracameral vancomycin after phaco-emusification cataract surgery to prevent endophthalmitis. Method: A total of 768 cases who had undergone phaco-emusification cataract surgery were included in the study. Every alternate patient received 0.5 ml injection of vancomycin (1mg in 0.1 ml in the anterior chamber after completion of phaco-emulcification and formation of anterior chamber. All the patients were examined for symptoms and signs of bacterial endophthalmitis at 24 hrs, 7 days, 15 days and subsequently at 1, 3 and 6 months following surgery. Results: No endophthalmitis case was recorded at any time period during 6 month follow up in either group. However, significantly higher number of cases in vancomycin group had cells in anterior chamber and disturbances in visual acuity at day 15 following surgery. Conclusion: Vancomycin did not have any prophylactic role in preventing endophthalmitis. Proper aseptic measures are important to prevent any infection in ocular surgery. IMC J Med Sci 2016; 10(1: 24-28

Determination of Serotypes and Antibiotic Resistance in Streptococcus Pneumoniae

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Deniz Akgun Karapinar

2016-01-01

Full Text Available Aim: In this study, the distribution of serogroup/serotype and antibiotic susceptibility testing of Streptococcus pneumoniae strains, recovered from pediatric and adult patients were evaluated. Material and Method: A total of 80 clinical isolates recovered from 19 pediatric and 61 adult patients were performed by latex aglutination method and antibiotic susceptibility tests in Istanbul University, Istanbul Faculty of Medicine, Medical Microbiology Laboratories. Results: Sixty-two strains (76 %, were serogroup/serotyped and 18 (23 % strains couldn%u2019t serogroup/serotyped. The most frequent identified serogroups were 19, 14, 23, 6, 4 in pediatrics, and 3, 19, 23 and 9 in adults. In adults, serogroups 3, 9, 5, 8, 18, 1, 15 were determined, but these serogroups weren%u2019t found in pediatrics. Vaccine serotypes rates were found as 53 % in pediatric and as 85 % in adults. The serogroups 2, 7, 10, 11, 12, 17, 20, 22, 33 were not detected, which are available in vaccine serotypes. Only 1 (1 % strain was found to exhibit low level resistance to penicillin and high level resistance wasn%u2019t found in any strain. Resistant results for trimethoprim-sulfamethoxazole, erythromycin, chloramphenicol and ofloxacin were found as 45 (56 %, 22 (27.5 %, 7 (9 %, 2 (2.5 %, respectively. All strains were found susceptible to vancomycin, linezolid and levofloxacin. The most resistant serogroups were 19, 23, 9 and 14 in the tested antibiotics. Multidrug resistance was found in 9 (11 % strains and these strains were found as serogroups 19, 23, 9, 6 and 14. Discussion: The epidemiological studies are important that the distribution of serotype and antibiotic resistance vary depending on many factors like age, and geographic region.

Evaluation of body weight-based vancomycin therapy and the incidence of nephrotoxicity: a retrospective study in the northwest of China.

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Dong, Mo-Han; Wang, Jing-Wen; Wu, Yin; Chen, Bei-Yu; Yu, Min; Wen, Ai-Dong

2015-08-01

To identify specific risk factors of vancomycin-induced nephrotoxicity in China, as the relationship between vancomycin therapy (dosing and trough concentration monitoring) and nephrotoxicity has been the subject of critical debate. The cases of 90 critically ill patients who received vancomycin therapy in Xijing Hospital in the northwest of China between March 2014 and January 2015 were reviewed retrospectively. Vancomycin dosing, blood serum trough concentration, and other independent risk factors associated with nephrotoxicity were evaluated in a multivariable model. Among the 90 critically ill patients, 59 were males; mean age was 46.3 years. The indications for vancomycin use were methicillin-resistant Staphylococcus aureus-associated pneumonia, central nervous system infection, and bacteremia. Clinical pharmacists prescribed weight-based dosing, ranging from 20 to 45mg/kg/day. Fourteen (15.6%) patients developed nephrotoxicity, with serum creatinine elevated significantly from a mean (standard deviation) of 90.0 (18.8) μmol/l to 133.8 (63.2) μmol/l (p = 0.015). It was found that those with a vancomycin dosage >38mg/kg/day (50.0% vs. 11.3%, p = 0.004) and a vancomycin serum trough concentration >20mg/l (57.1% vs. 12.0%, p = 0.01) were more likely to develop nephrotoxicity. The data from this study indicate that a vancomycin dosage >38mg/kg/day and a serum trough level >20mg/l are both independent factors associated with the development of nephrotoxicity, suggesting that renal function should be monitored closely during vancomycin treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Avaliação da tolerância à vancomicina em 395 cepas hospitalares de Staphylococcus aureus resistentes à oxacilina Evaluation of the tolerance to vancomycin in 395 oxacillin-resistant Staphylococcus aureus strains isolated from Brazilian hospitals

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Geraldo A. Oliveira

2001-01-01

Full Text Available O objetivo deste estudo foi avaliar a presença de tolerância à vancomicina em cepas de Staphylococcus aureus resistentes à oxacilina (Orsa isoladas de quatro hospitais da cidade de São Paulo. Foram estudadas 395 cepas Orsa isoladas de pacientes hospitalizados entre outubro de 1998 e maio de 2000. A determinação da concentração inibitória mínima (CIM e da concentração bactericida mínima (CBM para vancomicina foi realizada conforme padronizado pelo National Committee for Clinical Laboratory Standards (NCCLS. A tolerância à vancomicina foi definida como a razão CBM/CIM > ou = 32. Do total de cepas estudadas, 10,4% apresentaram CIM de 0,5µg/ml para vancomicina; 41,3%, CIM de 1µg/ml; 42,2%, CIM de 2µg/ml; e 6,1%, CIM de 4µg/ml. Em média, 49,1% dos Orsa apresentaram tolerância à vancomicina. Em conclusão, a tolerância à vancomicina entre as cepas Orsa foi considerada elevada. Conseqüentemente, aumentam as chances de falhas no tratamento com vancomicina, além de aumentar o risco da emergência de Staphylococcus aureus vancomicina-intermediário.The objective of this study was to evaluate the presence of tolerance to vancomycin in oxacillin-resistant Staphylococcus aureus (Orsa strains isolated from four hospitals in the city of São Paulo. From October/1998 to May/2000 we analysed 395 Orsa strains isolated from hospitalized patients. MIC and MBC to vancomycin were determined as standardised by National Committee for Clinical Laboratory Standards (NCCLS. Tolerance was defined as the ratio MBC/MIC > or = 32. The results showed that 10.4% of the Orsa strains presented a MIC of 0.5µg/mL for vancomycin, 41.3% presented a MIC of 1µg/mL, 42.2% a MIC of 2µg/mL and 6.1% a MIC of 4µg/mL. On average, 49,1% of the Orsa presented tolerance to vancomycin. We conclude that the tolerance to vancomycin amongst the Orsa strains was considered high. These high levels of tolerance augment the chances of failure in the treatment with

Are Vancomycin Trough Concentrations of 15 to 20 mg/L Associated With Increased Attainment of an AUC/MIC ≥ 400 in Patients With Presumed MRSA Infection?

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Hale, Cory M; Seabury, Robert W; Steele, Jeffrey M; Darko, William; Miller, Christopher D

2017-06-01

To determine whether there is an association between higher vancomycin trough concentrations and attainment of a calculated area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) ≥400. A retrospective analysis was conducted among vancomycin-treated adult patients with a positive methicillin-resistant Staphylococcus aureus (MRSA) culture. Attainment of a calculated AUC/MIC ≥400 was compared between patients with troughs in the reference range of 15 to 20 mg/L and those with troughs in the following ranges: 20 mg/L. Nephrotoxicity was assessed as a secondary outcome based on corrected average vancomycin troughs over 10 days of treatment. Overall, 226 patients were reviewed and 100 included. Relative to troughs ≥10, patients with vancomycin troughs AUC/MIC ≥400 (odds ratio [OR] 0.27, 95% confidence interval [CI]: 0.01-0.75). No difference was found in the attainment of an AUC/MIC ≥400 in patients with troughs of 10 to 14.9 mg/L and >20 mg/L when compared to patients with troughs of 15 to 20 mg/L. The mean corrected average vancomycin trough was higher in patients developing nephrotoxicity compared to those who did not (19.5 vs 14.5 mg/L, P AUC/MIC target relative to troughs of 10 to 14.9 mg/L but may increase nephrotoxicity risk.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

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Lívia Viganor da Silva

2011-02-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative Staphylococcus spp (CNS are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT, VAN plus rifampin (RIF and VAN plus imipenem (IPM in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.

Treatment of Clostridium difficile infection in mice with vancomycin alone is as effective as treatment with vancomycin and metronidazole in combination

DEFF Research Database (Denmark)

Erikstrup, Lise Tornvig; Aarup, Mie; Hagemann-Madsen, Rikke

2015-01-01

OBJECTIVE: Clostridium difficile is a major cause of nosocomial infectious diarrhoea. Treatment of C. difficile infection (CDI) depends on disease severity. A combination of vancomycin and metronidazole is often recommended in severe cases. The aim of this study was to examine, in a murine model....... difficile toxins. RESULTS: None of the mice in the vancomycin-treated group died during the treatment phase compared to a mortality of 17%, 33% and 55% in the combination, metronidazole and infected control group, respectively. Mice treated with vancomycin alone or in combination with metronidazole...... of CDI, if mice treated with a combination of vancomycin and metronidazole had a better clinical outcome than mice treated with vancomycin or metronidazole alone. DESIGN: C57BL/6J mice pretreated with an antimicrobial mixture were challenged with C. difficile VPI 10463 or phosphate-buffered saline...

Characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolate from a dog with mastitis: further evidence of a clonal lineage of VREF in New Zealand.

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Manson, Janet M; Keis, Stefanie; Smith, John M B; Cook, Gregory M

2003-07-01

We report here on the characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolated from a dog with mastitis. The isolate was positive for the vanA, ermB, and tet(M) genes, with vanA and ermB carried on the same transferable plasmid. Comparison of this isolate with VREF from poultry and human sources in New Zealand demonstrated identical SmaI macrorestriction patterns and Tn1546-like elements. This is further evidence of a clonal lineage of VREF in New Zealand.

Antibiotic Resistance Pattern of Staphylococcus aureus Strains Isolated from Personnel of Jahrom Hospitals in 2012

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S Saadat

2014-01-01

Undo edits Methods: In this cross - sectional study, 397 of the anterior nasal samples of medical personnel and hospital services were collected by swab. The identification of S.aureus was determined by biochemical tests and microbiology, and the antibiotic resistances of isolates were determined by disk diffusion method for 13 antibiotics. In this method, the inhibition zone for methicillin-resistant strains was ≤ 10 mm the minimum inhibitory concentrations (MIC against antibiotic vancomycin, ticoplanin, linezolid and synercid were determined by E-test method. Results: In the present study, 11.3% of personals carried S. aureus in the nose. Among them, 90% were health care workers and 10% were health service workers. The most sensitivity was observed resistance to Ciprofloxacin, rifampin, linezolid and synercid (91.1%, but the lowest sensitivity was to penicillin (4.7%. of 9 MRSA strains, 1 strain was resistance to vancomycin and 2 strains were resistant to teicoplanin and linezolid. Conclusion: Because of S. aureus strains isolated from hospital staffs were resistant to most common antibiotics, identification and treatment of health care and health service workers can prevent nosocomial infections. Key words: Staphylococcu aureus carriers, hospital personnel, antibiotic resistance.

A dirty cause of vancomycin-mediated Henoch-Schonlein purpura: oxygen tubing is not a foley.

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Shah, Nikhil H; Kline, Kristopher P; Shukla, Manas K

2017-06-20

A 59-year-old male presented with methicillin-resistant Staphylococcus aureus bacteraemia from a prostatic abscess and was treated with vancomycin. Two weeks into his treatment course, he developed severe joint pains, abdominal pain with bloody, mucinous stools and a diffuse palpable purpuric rash on his extremities. Biopsy of the rash showed IgA immune-complex deposition consistent with Henoch-Schönlein purpura. After treatment with glucocorticoids, his symptoms resolved completely. Vancomycin is an extremely commonly used antibiotic with certain well-known adverse effects. Henoch-Schönlein purpura, a vasculitis involving abdominal pain, arthralgias and palpable purpura, is a much less common side effect, as seen in this patient. Given that vancomycin is widely used internationally, clinicians should be aware of the risks entailed by its use. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria

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Talei, Gholam-Reza; Mohammadi, Mohsen; Bahmani, Mahmoud; Kopaei, Mahmoud Rafieian

2017-01-01

Background: Infectious diseases have always been an important health issue in human communities. In the recent years, much research has been conducted on antimicrobial effects of nature-based compounds because of increased prevalence of antibiotic resistance. The present study was conducted to investigate synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria. Materials and Methods: In this experimental study, the synergistic effects of C. copticum and M. piperita essential oils with antibiotics on Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus epidermidis (ATCC 14990), and Listeria monocytogenes (ATCC 7644) were studied according to broth microdilution and the MIC and fractional inhibitory concentration (FIC) of these two essential oils determined. Results: C. copticum essential oil at 30 μg/ml could inhibit S. aureus, and in combination with vancomycin, decreased MIC from 0.5 to 0.12 μg/ml. Moreover, the FIC was derived 0.24 μg/ml which represents a potent synergistic effect with vancomycin against S. aureus growth. C. copticum essential oil alone or combined with other antibiotics is effective in treating bacterial infections. Conclusions: In addition, C. copticum essential oil can strengthen the activities of certain antibiotics, which makes it possible to use this essential oil, especially in drug resistance or to lower dosage or toxicity of the drugs. PMID:28929050

The role of side stream dark field microvasculature imaging in a rare case of vancomycin-resistant enterococcal endocarditis complicated by heparin-induced thrombocytopenia

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Janak Bechar

2016-01-01

Full Text Available Sidestream dark field (SDF imaging allows direct visualization of microvascular architecture and function. We examine the role of an SDF imaging device in visualizing the sub-lingual microvasculature as a surrogate for splanchnic microperfusion. We demonstrate good correlation between current monitoring techniques and the SDF imaging device in a rare case of vancomycin-resistant enterococcal (VRE sepsis along with heparin-induced thrombocytopenia (HIT. To the best of our knowledge, VRE endocarditis with concurrent HIT has not been described in literature. The role of SDF imaging may predict the earlier need for escalation of care, improving morbidity and mortality.

Population pharmacokinetics of vancomycin in Jordanian patients

African Journals Online (AJOL)

predictors of vancomycin clearance include: weight, serum creatinine, chronic renal ... (http://www.budapestopenaccessinitiative.org/read), which permit ... reproduction in any medium, provided the original work is properly credited. ... fluid balance; and albumin levels]); (3) .... vancomycin half-life is prolonged in patients with.

Red man syndrome caused by vancomycin powder.

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Nagahama, Yasunori; VanBeek, Marta J; Greenlee, Jeremy D W

2018-04-01

Red man syndrome (RMS) is a well-known hypersensitivity reaction caused by intravenous administration of vancomycin, with symptoms ranging from flushing, erythematous rash, pruritus, mild to profound hypotension, and even cardiac arrest. RMS has not previously been described from local application of vancomycin powder in a surgical wound, a technique increasingly utilized for infection prophylaxis in many surgical disciplines including neurosurgery. We describe the first reported case of RMS as a result of local intra-wound application of vancomycin powder for infection prophylaxis. A 73-year-old male with a history of Parkinson's disease underwent 2-stage deep brain stimulation implantation surgeries. Vancomycin powder was applied locally in the surgical wounds for infection prophylaxis during both of the surgeries. The patient developed a well-demarcated, geometric erythematous pruritic rash following the second surgery that was clinically diagnosed as RMS and resolved without sequelae. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effectiveness of local vancomycin powder to decrease surgical site infections: a meta-analysis.

Science.gov (United States)

Chiang, Hsiu-Yin; Herwaldt, Loreen A; Blevins, Amy E; Cho, Edward; Schweizer, Marin L

2014-03-01

Some surgeons use systemic vancomycin to prevent surgical site infections (SSIs), but patients who do not carry methicillin-resistant Staphylococcus aureus have an increased risk of SSIs when given vancomycin alone for intravenous prophylaxis. Applying vancomycin powder to the wound before closure could increase the local tissue vancomycin level without significant systemic levels. However, the effectiveness of local vancomycin powder application for preventing SSIs has not been established. Our objective was to systematically review and evaluate studies on the effectiveness of local vancomycin powder for decreasing SSIs. Meta-analysis. We included observational studies, quasi-experimental studies, and randomized controlled trials of patients undergoing surgical procedures that involved vancomycin powder application to surgical wounds, reported SSI rates, and had a comparison group that did not use local vancomycin powder. The primary outcome was postoperative SSIs. The secondary outcomes included deep incisional SSIs and S. aureus SSIs. We performed systematic literature searches in PubMed, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, the Cochrane Central Register of Controlled Trials via Wiley, Scopus (including EMBASE abstracts), Web of Science, ClinicalTrials.gov, BMC Proceedings, ProQuest Dissertation, and Thesis in Health and Medicine, and conference abstracts from IDWeek, the Interscience Conference on Antimicrobial Agents and Chemotherapy, the Society for Healthcare Epidemiology of America, and the American Academy of Orthopedic Surgeons annual meetings, and also the Scoliosis Research Society Annual Meeting and Course. We ran the searches from inception on May 9, 2013 with no limits on date or language. After reviewing 373 titles or abstracts and 22 articles in detail, we included 10 independent studies and used a random-effects model when pooling risk estimates to assess the effectiveness of local

Gene expression analysis reveals new possible mechanisms of vancomycin-induced nephrotoxicity and identifies gene markers candidates.

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Dieterich, Christine; Puey, Angela; Lin, Sylvia; Lyn, Sylvia; Swezey, Robert; Furimsky, Anna; Fairchild, David; Mirsalis, Jon C; Ng, Hanna H

2009-01-01

Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip administration. Groups of six female BALB/c mice were treated with seven daily iv or ip doses of vancomycin (50, 200, and 400 mg/kg) or saline, and sacrificed on day 8. Clinical chemistry and histopathology demonstrated kidney injury at 400 mg/kg only. Hierarchical clustering analysis revealed that kidney gene expression profiles of all mice treated at 400 mg/kg clustered with those of mice administered 200 mg/kg iv. Transcriptional profiling might thus be more sensitive than current clinical markers for detecting kidney damage, though the profiles can differ with the route of administration. Analysis of transcripts whose expression was changed by at least twofold compared with vehicle saline after high iv and ip doses of vancomycin suggested the possibility of oxidative stress and mitochondrial damage in vancomycin-induced toxicity. In addition, our data showed changes in expression of several transcripts from the complement and inflammatory pathways. Such expression changes were confirmed by relative real-time reverse transcription-polymerase chain reaction. Finally, our results further substantiate the use of gene markers of kidney toxicity such as KIM-1/Havcr1, as indicators of renal injury.

Controlling antibiotic resistance in the ICU

NARCIS (Netherlands)

Derde, L.P.G.

2013-01-01

Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci

Therapeutic drug monitoring by radioimmunoassay: Determination of aminoglycoside antibiotics and vancomycin in plasma

International Nuclear Information System (INIS)

Glaubitt, D.; Drechsler, H.J.; Knoch, K.; Siafarikas, K.

1984-01-01

Radioimmunoassay of aminoglycoside antibiotics (gentamicin, tobramycin, netilmicin) or vancomycin in plasma may considerably aid to assess their appropriate dosage and, if necessary, to rapidly adjust it to the assumed requirement. Thus the dosage of the antibiotic is kept large enough as to lead to the desired therapeutic result but not as high as to cause side effects. (orig.)

Antimicrobial Resistance Profile of Planktonic and Biofilm Cells of Staphylococcus aureus and Coagulase-Negative Staphylococci

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Adilson de Oliveira

2016-09-01

Full Text Available The objective of the present study was to determine the antimicrobial resistance profile of planktonic and biofilm cells of Staphylococcus aureus and coagulase-negative staphylococci (CoNS. Two hundred Staphylococcus spp. strains were studied, including 50 S. aureus and 150 CoNS strains (50 S. epidermidis, 20 S. haemolyticus, 20 S. warneri, 20 S. hominis, 20 S. lugdunensis, and 20 S. saprophyticus. Biofilm formation was investigated by adherence to polystyrene plates. Positive strains were submitted to the broth microdilution method to determine the minimum inhibitory concentration (MIC for planktonic and biofilm cells and the minimal bactericidal concentration for biofilm cells (MBCB. Forty-nine Staphylococcus spp. strains (14 S. aureus, 13 S. epidermidis, 13 S. saprophyticus, 3 S. haemolyticus, 1 S. hominis, 3 S. warneri, and 2 S. lugdunensis were biofilm producers. These isolates were evaluated regarding their resistance profile. Determination of planktonic cell MIC identified three (21.4% S. aureus strains that were resistant to oxacillin and six (42.8% that were resistant to erythromycin. Among the CoNS, 31 (88.6% strains were resistant to oxacillin, 14 (40% to erythromycin, 18 (51.4% to gentamicin, and 8 (22.8% to sulfamethoxazole/trimethoprim. None of the planktonic isolates were resistant to vancomycin or linezolid. MICs were 2-, 4-, 8-, and up to 16-fold higher for biofilm cells than for planktonic cells. This observation was more common for vancomycin and erythromycin. The MBCB ranged from 8 to >256 µg/mL for oxacillin, 128 to >128 µg/mL for vancomycin, 256 to >256 µg/mL for erythromycin and gentamicin, >64 µg/mL for linezolid, and 32/608 to >32/608 µg/mL for sulfamethoxazole/trimethoprim. The results showed considerably higher MICs for S. aureus and CoNS biofilm cells compared to planktonic cells. Analysis of MBCM confirmed that even high concentrations of vancomycin were unable to eliminate the biofilms of S. aureus and Co

Vancomycin graft composite for infected bone defects

International Nuclear Information System (INIS)

Winkler, H.; Janata, O.; Georgopoulos, A.

1999-01-01

Reconstructive surgery under septic conditions represents a major challenge in orthopaedics. Local application of antibiotics can provide high drug levels at the site of infection without systemic effects. However, removal of non-resorbable implants and filling of defects usually requires additional operative procedures. An ideal antibiotic carrier should provide for : 1) Effective bactericidal activity, especially against staphylococci including MRSA; 2) High and long lasting levels at the site of infection without local or systemic toxicity; 3) Repair of defects without a second stage procedure. Allogeneic cancellous bone is proven to be effective in restoration of bone stock. Vancomycin is effective against all gram-positive populations and the agent of choice for infections with MRSA. The aim of our study is to investigate the efficacy of a combination of both components in bone infection. Cancellous bone of human origin was processed during several steps and incubated in 10% vancomycin solution. The antimicrobial activity of the vancomycin graft composite (VGC) was evaluated using an agar diffusion bioassay against staphylococcus aureus and high performance liquid chromatography (HPLC). The testing period was up to 9 weeks. Elution of vancomycin from the graft was evaluated in 2.5% human albumin solution, which was exchanged every 24 hours. Concentration of vancomycin in allograft-bone was between 6.653[tg/g and 23.194gg/g with an average of 15.250 [tg/g, which is equivalent to 10.000 times the minimum inhibitory concentration (MIC) for s. aureus. The initial activity decreased to approx. 50% during the first week and approx. 30% at the end of the 9th week. The lowest values measured exceeded the MIC by 2000 times. Concentration in surrounding fluid decreased from 24.395,80 to 18,43pg/ml after 11 complete exchanges. Human cancellous bone, processed in an adequate way, offers capability to store high quantities of vancomycin. Vancomycin graft composites are

Detection Antibiotic Resistance of Enviromental Bacterial Strains

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Huda Zuheir Majeed

2018-05-01

Full Text Available      Antibiotics are randomly prescribed  for veterinary and human medication. Antibiotics by little number are used by human , animals are digested uncompletely  in their digestive system and ended up in communal sewage and hospitals, eventually discharge in environmental water sources directly with no processing.     Water itself consider as major factor of dispersal of bacteria between different environmental components. Besides, bacteria had  transferable genetic mobile elements to different sites of soil, water and humans.       Environmental swabs were collected locally including 50 swabs of hospital environment , 15 samples of poultry feces and chicken guts , 20 sample of heavy water and 15 sample of fish tank to identify16 isolate of Staphylococcus (4 isolate of Staphylococus aureus and 12 isolate of coagulase –ve Staphylococcus , 19 isolate of Enterococcus spp. , 7 isolates of Pseudomonas and 5 environment isolates for each Shigella spp.  and Salmonella spp. .           Teicoplanin and Vancomycin sensitivity test of isolates was done , showing that 2out of 16 isolates of Staphylococcus (12.5% were Vancomycin-resistant , and 3out of 19 isolates of Enterococcus (15.7 % were Vancomycin-resistant, while the rest of isolates were Vancomycin- sensitive. From other side , all isolates was Teicoplanin- sensitive except only 1 Enterococcus spp. Isolate which was intermediate . The range of the Vancomycin MIC were (6-64 µg/ml . Vancomycin resistant isolates , showed that some isolates have one plasmid band after Extraction of their DNA.

Clinical and economic benefits of fidaxomicin compared to vancomycin for Clostridium difficile infection.

Science.gov (United States)

Gallagher, Jason C; Reilly, Joseph P; Navalkele, Bhagyashri; Downham, Gemma; Haynes, Kevin; Trivedi, Manish

2015-11-01

We studied the clinical and economic impact of a protocol encouraging the use of fidaxomicin as a first-line drug for treatment of Clostridium difficile infection (CDI) in patients hospitalized during a 2-year period. This study evaluated patients who received oral vancomycin or fidaxomicin for the treatment of CDI during a 2-year period. All included patients were eligible for administration of fidaxomicin via a protocol that encouraged its use for selected patients. The primary clinical endpoint was 90-day readmission with a diagnosis of CDI. Hospital charges and insurance reimbursements for readmissions were calculated along with the cost of CDI therapy to estimate the financial impact of the choice of therapy. Recurrences were seen in 10/49 (20.4%) fidaxomicin patients and 19/46 (41.3%) vancomycin patients (P = 0.027). In a multivariate analysis that included determinations of severity of CDI, serum creatinine increases, and concomitant antibiotic use, only fidaxomicin was significantly associated with decreased recurrence (adjusted odds ratio [aOR], 0.33; 95% confidence interval [CI], 0.12 to 0.93). The total lengths of stay of readmitted patients were 183 days for vancomycin and 87 days for fidaxomicin, with costs of $454,800 and $196,200, respectively. Readmissions for CDI were reimbursed on the basis of the severity of CDI, totaling $151,136 for vancomycin and $107,176 for fidaxomicin. Fidaxomicin drug costs totaled $62,112, and vancomycin drug costs were $6,646. We calculated that the hospital lost an average of $3,286 per fidaxomicin-treated patient and $6,333 per vancomycin-treated patient, thus saving $3,047 per patient with fidaxomicin. Fidaxomicin use for CDI treatment prevented readmission and decreased hospital costs compared to use of oral vancomycin. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

CORRELATION BETWEEN HYDROPHOBICITY AND RESISTANCE TO NONOXYNOL-9 AND VANCOMYCIN FOR UROGENITAL ISOLATES OF LACTOBACILLI

NARCIS (Netherlands)

TOMECZEK, L; REID, G; CUPERUS, PL; MCGROARTY, JA; VANDERMEI, HC; BRUCE, AW; KHOURY, AE; BUSSCHER, HJ

1992-01-01

Seven clinical isolates of lactobacilli were found to be relatively hydrophobic with a mean water-contact angle of 66 +/- 15 degrees, and to be susceptible to 1% nonoxynol-9 and vancomycin. However, seven other strains were relatively hydrophilic with a mean water-contact angle of 32 +/- 13 degrees,

Simultaneous and Direct Determination of Vancomycin and Cephalexin in Human Plasma by Using HPLC-DAD Coupled with Second-Order Calibration Algorithms

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Le-Qian Hu

2012-01-01

Full Text Available A simple, rapid, and sensitive method for the simultaneous determination of vancomycin and cephalexin in human plasma was developed by using HPLC-DAD with second-order calibration algorithms. Instead of a completely chromatographic separation, mathematical separation was performed by using two trilinear decomposition algorithms, that is, PARAFAC-alternative least squares (PARAFAC-ALSs and self-weight-alternative-trilinear-decomposition- (SWATLD- coupled high-performance liquid chromatography with DAD detection. The average recoveries attained from PARAFAC-ALS and SWATLD with the factor number of 4 (N=4 were 101±5% and 102±4% for vancomycin, and 96±3% and 97±3% for cephalexininde in real human samples, respectively. The statistical comparison between PARAFAC-ALS and SWATLD is demonstrated to be similar. The results indicated that the combination of HPLC-DAD detection with second-order calibration algorithms is a powerful tool to quantify the analytes of interest from overlapped chromatographic profiles for complex analysis of drugs in plasma.

Genome-wide identification of antimicrobial intrinsic resistance determinants in Staphylococcus aureus

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Martin Vestergaard

2016-12-01

Full Text Available The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin and gentamicin. 68 mutants were confirmed by E-test to display at least two-fold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.

Molecular characterization of van genes found in vancomycin-resistant Enterococcus spp. isolated from Hospital das Clínicas, FMUSP, São Paulo, Brazil

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H.H. Caiaffa Filho

Full Text Available Vancomycin-resistant enterococci strains (VRE is an important pathogen related with hospital infections in many countries, presenting limited or no therapeutic options for treating serious infections. VRE has presented some different genotypes been VanA and VanB considered to be the most important in hospital environments. In the present study the authors investigated the prevalence of van genes (A, B an C among clinical isolates of VRE in a five month period at a large tertiary hospital in Sao Paulo, Brazil. The results showed the presence of vanA, but not vanB or vanC in all 43 strains of E. faecalis and five E. faecium studied. The results bring an important issue, due to the possibility of resistance spread of vanA genes, to be monitored and solved by the hospital infection control team and the microbiology and molecular biology laboratories at tertiary Hospitals.

Hypogammaglobulinemia and Poor Performance Status are Predisposing Factors for Vancomycin-Resistant Enterococcus Colonization in Patients with Hematological Malignancies

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Elif Gülsüm Ümit

2017-03-01

Full Text Available Objective: Vancomycin-resistant enterococci (VRE are common pathogens of hospital-acquired infection. Long hospitalization periods, use of broadspectrum antibiotics, and immunosuppression are major risks for VRE colonization. We aimed to evaluate patients’ characteristics and factors that may contribute to VRE colonization. Materials and Methods: Data of 66 patients with colonization and 112 patients without colonization who were hospitalized in the hematology clinic were collected. Hematological malignancies, preexisting gastrointestinal complaints, the presence of hypogammaglobulinemia at the time of diagnosis, complications like neutropenic enterocolitis (NEC, and Eastern Cooperative Oncology Group (ECOG and Karnofsky performance statuses were recorded. Results: Ages of the patients ranged between 19 and 95 years (mean: 55.99. Karnofsky and ECOG scores were statistically related to VRE colonization (p7 days may also be accepted as a risk factor, independent of diagnosis or antibiotic use. Performance status is also an important factor for colonization, which may be related to poorer hygiene and increased external help.

Elimination of Routine Contact Precautions for Endemic Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus: A Retrospective Quasi-Experimental Study.

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Martin, Elise M; Russell, Dana; Rubin, Zachary; Humphries, Romney; Grogan, Tristan R; Elashoff, David; Uslan, Daniel Z

2016-11-01

OBJECTIVE To evaluate the impact of discontinuation of contact precautions (CP) for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) and expansion of chlorhexidine gluconate (CHG) use on the health system. DESIGN Retrospective, nonrandomized, observational, quasi-experimental study. SETTING Two California hospitals. PARTICIPANTS Inpatients. METHODS We compared hospital-wide laboratory-identified clinical culture rates (as a marker of healthcare-associated infections) 1 year before and after routine CP for endemic MRSA and VRE were discontinued and CHG bathing was expanded to all units. Culture data from patients and cost data on material utilization were collected. Nursing time spent donning personal protective equipment was assessed and quantified using time-driven activity-based costing. RESULTS Average positive culture rates before and after discontinuing CP were 0.40 and 0.32 cultures/100 admissions for MRSA (P=.09), and 0.48 and 0.40 cultures/100 admissions for VRE (P=.14). When combining isolation gown and CHG costs, the health system saved $643,776 in 1 year. Before the change, 28.5% intensive care unit and 19% medicine/surgery beds were on CP for MRSA/VRE. On the basis of average room entries and donning time, estimated nursing time spent donning personal protective equipment for MRSA/VRE before the change was 45,277 hours/year (estimated cost, $4.6 million). CONCLUSION Discontinuing routine CP for endemic MRSA and VRE did not result in increased rates of MRSA or VRE after 1 year. With cost savings on materials, decreased healthcare worker time, and no concomitant increase in possible infections, elimination of routine CP may add substantial value to inpatient care delivery. Infect Control Hosp Epidemiol 2016;1-8.

Pharmacist-led implementation of a vancomycin guideline across medical and surgical units: impact on clinical behavior and therapeutic drug monitoring outcomes

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Phillips CJ

2015-10-01

Full Text Available Cameron J Phillips,1–3 David L Gordon3,4 1Division of Pharmacy, SA Pharmacy, Flinders Medical Centre, Bedford Park, 2School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, 3Department of Microbiology and Infectious Diseases, School of Medicine, Flinders University, Adelaide, 4Department of Microbiology and Infectious Diseases, SA Pathology, Flinders Medical Centre, Bedford Park, SA, Australia Background: Vancomycin is the antibiotic of choice for the treatment of serious infections such as methicillin-resistant Staphylococcus aureus (MRSA. Inappropriate prescribing of vancomycin can lead to therapeutic failure, antibiotic resistance, and drug toxicity. Objective: To examine the effectiveness of pharmacist-led implementation of a clinical practice guideline for vancomycin dosing and monitoring in a teaching hospital. Methods: An observational pre–post study design was undertaken to evaluate the implementation of the vancomycin guideline. The implementation strategy principally involved education, clinical vignettes, and provision of pocket guidelines to accompany release of the guideline to the hospital Intranet. The target cohort for clinical behavioral change was junior medical officers, as they perform the majority of prescribing and monitoring of vancomycin in hospitals. Assessment measures were recorded for vancomycin prescribing, therapeutic drug monitoring, and patient outcomes. Results: Ninety-nine patients, 53 pre- and 46 post-implementation, were included in the study. Prescribing of a loading dose increased from 9% to 28% (P=0.02, and guideline adherence to starting maintenance dosing increased from 53% to 63% (P=0.32. Dose adjustment by doctors when blood concentrations were outside target increased from 53% to 71% (P=0.12, and correct timing of initial concentration measurement increased from 43% to 57% (P=0.23. Appropriately timed trough concentrations improved from 73% to 81% (P=0.08. Pre-dose (trough

Performance of the EUCAST disk diffusion method, the CLSI agar screen method, and the Vitek 2 automated antimicrobial susceptibility testing system for detection of clinical isolates of Enterococci with low- and medium-level VanB-type vancomycin resistance

DEFF Research Database (Denmark)

Hegstad, Kristin; Giske, Christian G; Haldorsen, Bjørg

2014-01-01

faecium (n=18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n=5), Norwegian (n=13), and Swedish (n=10) laboratories using the EUCAST disk diffusion method (n=28) and the CLSI agar screen (n=18) or the Vitek 2 system (bioMérieux) (n=5). The EUCAST disk diffusion...... method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P=0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME...... rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P

An investigation of vancomycin minimum inhibitory concentration creep among methicillin-resistant Staphylococcus aureus strains isolated from pediatric patients and healthy children in Northern Taiwan

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Chia-Ning Chang

2017-06-01

Conclusion: Vancomycin MIC creeps existed in both clinical MRSA isolates and colonized MRSA strains. Great diversity of PFGE typing was in both strains collected. There was no association between the clinical and colonized MRSA isolates with vancomycin MIC creep.

Implementation of the systems approach to improve a pharmacist-managed vancomycin dosing service.

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Gagnon, David J; Roberts, Russel; Sylvia, Lynne

2014-12-01

Quality improvements achieved by applying the systems approach to assess the clinical effectiveness, operational efficiency, and financial feasibility of a pharmacist-managed vancomycin dosing service are described. Faced with increased patient volumes and resource demands, the pharmacy department at Tufts Medical Center conducted an evaluation of its adult inpatient vancomycin dosing service using the systems approach, which emphasizes multidisciplinary assessment of system inputs, processes, and outcomes and consensus-building methods to identify needed changes and recommended action steps. A multidisciplinary committee composed of representatives of the medical center's pharmacy, internal medicine, infectious diseases, nursing, phlebotomy, and clinical laboratory services was assembled; in a series of three moderated monthly sessions, committee members deliberated and ultimately reached consensus on a list of action items. Relative to a concurrent intradepartmental assessment of the vancomycin dosing service based solely on pharmacist feedback, the systems approach identified a greater number and wider array of needed improvements in key program areas. Quality improvements implemented as a direct result of the systems-based analysis included a policy change authorizing pharmacists to order serum vancomycin determinations without physician cosignature and inclusion of a vancomycin dosing algorithm in the institutional antibiotic dosing guide. Future changes based on deliverable action items will result in a structured process to help direct program resources toward the patients most in need of pharmacist-managed vancomycin dosing services. The systems approach allowed for a comprehensive multidisciplinary evaluation of the service, as indicated by the identification of process improvements not identified by the department of pharmacy alone. Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Preparation and biodistribution of [201Tl](III)vancomycin complex in normal rats

International Nuclear Information System (INIS)

Jalilian, A.R.; Hosseini, M.A.; Karimian, A.; Saddadi, F.; Sadeghi, M.

2006-01-01

Thallium-201 (T 1/2 = 3.04 days) in Tl + form was converted to Tl 3+ cation in presence of O 3 in 6 M HCl controlled by RTLC/gel electrophoresis methods. The final evaporated activity was reacted with vancomycin (VAN) in water to yield [ 201 Tl](III)VAN. The best results were obtained at room temperature in water after 30 min with a radiochemical yield >99%, after mixing the reactants followed by SPE purification using Si Sep-Pak. The studies showed that thallic ion is mostly incorporated into vancomycin with a radiochemical purity of more than 98 ± 1% by RTLC. A specific activity of about 4.14·10 10 Bq/mmol was obtained. Radiochemical purity and stability of 201 Tl-VAN in the preparation and in presence of human serum was determined up to 5.5 days. Biodistribution study of 201 Tl(III)-vancomycin in normal rats was performed up to 52 h. (authors)

A Rare Case of Vancomycin-Induced Linear Immunoglobulin A Bullous Dermatosis

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Pinky Jha

2017-01-01

Full Text Available Linear IgA bullous dermatosis (LABD is an autoimmune vesiculobullous disease, which is typically idiopathic but can also rarely be caused by medications or infections. Vancomycin is the most common drug associated with LABD. Lesions typically appear 24 hours to 15 days after the first dose of vancomycin. It is best characterized pathologically by subepidermal bulla (blister formation with linear IgA deposition at the dermoepidermal junction. Here we report an 86-year-old male with a history of left knee osteoarthritis who underwent a left knee arthroplasty and subsequently developed a prosthetic joint infection. This infection was treated with intravenous vancomycin as well as placement of a vancomycin impregnated joint spacer. Five days following initiation of antibiotic therapy, he presented with a vesiculobullous eruption on an erythematous base over his trunk, extremities, and oral mucosa. The eruption resolved completely when intravenous vancomycin was discontinued and colchicine treatment was begun. Curiously, complete resolution occurred despite the presence of the vancomycin containing joint spacer. The diagnosis of vancomycin-induced linear IgA bullous dermatosis was made based on characteristic clinical and histopathologic presentations.

Product quality of parenteral vancomycin products in the United States.

Science.gov (United States)

Nambiar, S; Madurawe, R D; Zuk, S M; Khan, S R; Ellison, C D; Faustino, P J; Mans, D J; Trehy, M L; Hadwiger, M E; Boyne, M T; Biswas, K; Cox, E M

2012-06-01

In response to concerns raised about the quality of parenteral vancomycin products, the U.S. Food and Drug Administration (FDA) is investigating the product quality of all FDA-approved parenteral vancomycin products available in the United States. Product quality was evaluated independently at two FDA Office of Testing and Research (FDA-OTR) sites. In the next phase of the investigation, being done in collaboration with the National Institute of Allergy and Infectious Diseases, the in vivo activity of these products will be evaluated in an appropriate animal model. This paper summarizes results of the FDA investigation completed thus far. One site used a validated ultrahigh-pressure liquid chromatography method (OTR-UPLC), and the second site used the high-performance liquid chromatography (HPLC) method for related substances provided in the British Pharmacopeia (BP) monograph for vancomycin intravenous infusion. Similar results were obtained by the two FDA-OTR laboratories using two different analytical methods. The products tested had 90 to 95% vancomycin B (active component of vancomycin) by the BP-HPLC method and 89 to 94% vancomycin by OTR-UPLC methods. Total impurities were 5 to 10% by BP-HPLC and 6 to 11% by OTR-UPLC methods. No single impurity was >2.0%, and the CDP-1 level was ≤ 2.0% across all products. Some variability in impurity profiles of the various products was observed. No adverse product quality issues were identified with the six U.S. vancomycin parenteral products. The quality parameters of all parenteral vancomycin products tested surpassed the United States Pharmacopeia acceptance criteria. Additional testing will characterize in vivo performance characteristics of these products.

An Approach to Optimise Therapeutic Vancomycin Dosage in a Haemodialysis Population

LENUS (Irish Health Repository)

Gunning, H

2016-10-01

Haemodialysis patients are at risk of gram-positive bacteraemia and commonly require intravenous vancomycin. Intravenously administered vancomycin is primarily excreted by the kidney and exhibits complex pharmacokinetics in haemodialysis patients; achieving therapeutic levels can be challenging. An audit in our unit showed current practises of vancomycin administration resulted in a high proportion of sub-therapeutic levels. A new protocol was developed with fixed weight-based loading and subsequent dosing guided by pre-dialysis levels, target levels were 10-20mg\\/L. Its effectiveness was prospectively evaluated between 24th September 2012, and 8th February 2013. During this period 25 patients commenced vancomycin, 15 were included. In total, 112 vancomycin levels were taken, 94 (84%) were therapeutic, this was a significant improvement compared to previous practise (odds ratio 5.4, CI 3.1-9.4, p < 0.0001). In conclusion, our study shows this protocol can consistently and reliably achieve therapeutic vancomycin levels

Evaluating guideline adherence regarding empirical vancomycin use in patients with neutropenic fever

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Daniel B. Chastain

2018-04-01

Full Text Available Objective: The purpose of this study was to evaluate the use of empirical vancomycin for patients with neutropenic fever (NF with regard to adherence to treatment guidelines. Methods: Adult patients with a diagnosis of neutropenia, who met the definition of NF as per treatment guidelines, were identified. Use of vancomycin was evaluated as part of empirical therapy and again after 72 h. Outcomes were assessed using descriptive statistics, the Chi-square or Fisher’s exact test, and univariate exact logistic regression analyses. Results: Sixty-four patients were included. Overall, inappropriate empirical vancomycin use was observed in more than 30% of patients. Of 35 patients with indications for empirical vancomycin, only 68% received it. At 72 h, appropriate vancomycin continuation, de-escalation, or discontinuation occurred in 21 of 33 patients. On univariate regression, hematological malignancy was associated with appropriate empirical vancomycin prescribing, whether initiating or withholding (odds ratio 4.0, 95% confidence interval 1.31–12.1. No variable was independently associated with inappropriate continuation at 72 h. Conclusions: There is poor guideline adherence to vancomycin prescribing as empirical therapy and at 72-h reassessment in patients with NF. Further efforts are needed to foster a more rational use of vancomycin in patients with NF. Keywords: Antibiotics, Neutropenia, Neutropenic fever, Vancomycin

Proactive infection control measures to prevent nosocomial transmission of vancomycin-resistant enterococci in Hong Kong.

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Cheng, Vincent Chi-Chung; Tai, Josepha Wai-Ming; Chen, Jonathan Hon-Kwan; So, Simon Yung-Chun; Ng, Wing-Chun; Hung, Ivan Fan-Ngan; Leung, Sally Sau-Man; Wong, Sally Cheuk-Ying; Chan, Tuen-Ching; Chan, Felix Hon-Wai; Ho, Pak-Leung; Yuen, Kwok-Yung

2014-10-01

The study describes a proactive infection control approach to prevent nosocomial transmission of vancomycin-resistant enterococci (VRE) and tests if this approach is effective for controlling multiple-drug resistant organisms in a nonendemic setting. In response to the increasing prevalence of VRE in Hong Kong since 2011, we adopted a multifaceted assertive approach in our health care network. This included active surveillance culture, extensive contact tracing, directly observed hand hygiene in conscious patients before they received meals and medications, stringent hand hygiene and environmental cleanliness, and an immediate feedback antimicrobial stewardship program. We report the occurrence of VRE outbreaks in our hospital after institution of these measures and compared with the concurrent occurrence in other public hospitals in Hong Kong. Between July 1, 2011 and November 13, 2013, VRE was identified in 0.32% (50/15,851) of admission episodes by active surveillance culture. The risk of VRE carriage was three times higher in patients with a history of hospitalization outside our hospital networks in the past 3 months (0.56% vs. 0.17%; p = 0.001) compared with those who were not. Extensive contact tracing involving 3277 patient episodes was performed in the investigation for the 25 VRE index patients upon whom implementation of contact precautions was delayed (more than 48 hours of hospitalization). One episode of VRE outbreak was identified in our hospital network, compared with the 77 VRE outbreaks reported in the other hospital networks (controls) without these proactive infection control measures. Our multifaceted assertive proactive infection control approach can minimize the nosocomial transmission and outbreak of VRE in a nonendemic area. Copyright © 2014. Published by Elsevier B.V.

Trough Concentrations of Vancomycin in Patients Undergoing Extracorporeal Membrane Oxygenation.

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So Jin Park

Full Text Available To investigate the appropriateness of the current vancomycin dosing strategy in adult patients with extracorporeal membrane oxygenation (ECMO, between March 2013 and November 2013, patients who were treated with vancomycin while on ECMO were enrolled. Control group consisted of 60 patients on vancomycin without ECMO, stayed in medical intensive care unit during the same study period and with the same exclusion criteria. Early trough levels were obtained within the fourth dosing, and maintenance levels were measured at steady state. A total of 20 patients were included in the analysis in ECMO group. Sixteen patients received an initial intravenous dose of 1.0 g vancomycin followed by 1.0 g every 12 hours. The non-steady state trough level of vancomycin after starting administration was subtherapeutic in 19 patients (95.00% in ECMO group as compared with 40 patients (66.67% in the control group (p = 0.013. Vancomycin clearance was 1.27±0.51 mL/min/kg, vancomycin clearance/creatinine clearance ratio was 0.90 ± 0.37, and elimination rate constant was 0.12 ± 0.04 h-1. Vancomycin dosingfrequency and total daily dose were significantly increased after clinical pharmacokinetic services of the pharmacist based on calculated pharmacokinetic parameters (from 2.10 ± 0.72 to 2.90 ± 0.97 times/day, p = 0.002 and from 32.54 ± 8.43 to 42.24 ± 14.62mg/kg, p = 0.014 in ECMO group in contrast with those (from 2.11 ± 0.69 to 2.37 ± 0.86 times/day, p = 0.071 and from 33.91 ± 11.85 to 31.61 ± 17.50 mg/kg, p = 0.350 in the control group.Although the elimination rate for vancomycin was similar with population parameter of non ECMO patients, the current dosing strategy of our institution for vancomycinin our ICU was not sufficient to achieve the target trough in the initial period in most patients receiving ECMO.

Antimicrobial Resistance

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... past two decades due to the increase in immunocompromised and elderly patients, increasing use of invasive indwelling ... aureus developing resistance to vancomycin, a very powerful antibiotic prescribed for the most intractable bacterial infections. In ...

Glycopeptide resistance in Enterococcus faecium from broilers and pigs following discontinued use of avoparcin

DEFF Research Database (Denmark)

Bager, Flemming; Aarestrup, Frank Møller; Madsen, Mogens

1999-01-01

The use of the glycopeptide growth promoter avoparcin was discontinued in Denmark in 1995 following concerns that vancomycin-resistant Enterococcus faecium occurring as a result of its use could be transferred to humans via food. The present study is an analysis of results obtained by the continu......The use of the glycopeptide growth promoter avoparcin was discontinued in Denmark in 1995 following concerns that vancomycin-resistant Enterococcus faecium occurring as a result of its use could be transferred to humans via food. The present study is an analysis of results obtained...... by the continuous surveillance of an antimicrobial resistance in Denmark (DANMAP) with the aim of determining the effect of the ban on the occurrence of glycopeptide resistance among E, faecium isolated from broilers and pigs, Among isolates from broilers, the proportion that were resistant to glycopeptides has....... Alternatively, the results indicate that the different outcomes may result from different co-selection patterns in pigs and broilers. In pigs, the antimicrobials most commonly used favored co-selection of glycopeptide-resistant strains of E. faecium while in broilers the antimicrobials most widely used selected...

Vancomycin-Resistant Enterococci (VRE):Overview

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... Prevention. In 1984, enterococci was given its own genus identity. In 1986, the first VRE strains appeared ... on March 9, 2009 Antimicrobial (Drug) Resistance NIAID's Role Goals Accomplishments Basic Research Translating Basic Knowledge Research ...

Molecular Characterization of Glycopeptide-Resistant Enterococci from Hospitals of the Picardy Region (France

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M. Biendo

2010-01-01

Full Text Available We studied 138 glycopeptide-resistant enterococci (GRE strains, consisting of 131 glycopeptide-resistant Enterococcus faecium (GREfm and 7 glycopeptide-resistant Enterococcus faecalis (GREfs. The GREfm strains were resistant to penicillin, ampicillin, vancomycin, and teicoplanin, while the GREfs strains were only resistant to vancomycin and teicoplanin. The van A gene was the only glycopeptide determinant present in all GRE isolates investigated. Genes coding for Hyl and Hyl+ Esp were detected in 39 (29.8% and 92 (70.2% of the 131 GREfm isolates, respectively. Three of the 7 GREfs were positive for gelE+asa 1 genes, 3 for gel E gene, and 1 for asa 1 gene. The genetic relationship between the 138 GRE was analyzed by pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. GREfm isolates were clustered in a single genogroup (pulsotype A, and GREfs were clustered in six genogroups (pulsotypes B-G. Among the isolates investigated by MLST, only 18 PCR products were sequenced (12 E. faecium and 6 E. faecalis, and 9 sequence types (STs were identified.

Evaluating guideline adherence regarding empirical vancomycin use in patients with neutropenic fever.

Science.gov (United States)

Chastain, Daniel B; Wheeler, Sarah; Franco-Paredes, Carlos; Olubajo, Babatunde; Hawkins, W Anthony

2018-04-01

The purpose of this study was to evaluate the use of empirical vancomycin for patients with neutropenic fever (NF) with regard to adherence to treatment guidelines. Adult patients with a diagnosis of neutropenia, who met the definition of NF as per treatment guidelines, were identified. Use of vancomycin was evaluated as part of empirical therapy and again after 72h. Outcomes were assessed using descriptive statistics, the Chi-square or Fisher's exact test, and univariate exact logistic regression analyses. Sixty-four patients were included. Overall, inappropriate empirical vancomycin use was observed in more than 30% of patients. Of 35 patients with indications for empirical vancomycin, only 68% received it. At 72h, appropriate vancomycin continuation, de-escalation, or discontinuation occurred in 21 of 33 patients. On univariate regression, hematological malignancy was associated with appropriate empirical vancomycin prescribing, whether initiating or withholding (odds ratio 4.0, 95% confidence interval 1.31-12.1). No variable was independently associated with inappropriate continuation at 72h. There is poor guideline adherence to vancomycin prescribing as empirical therapy and at 72-h reassessment in patients with NF. Further efforts are needed to foster a more rational use of vancomycin in patients with NF. Copyright © 2018. Published by Elsevier Ltd.

ISOLATION AND PURIFICATION OF STREPTOMYCES SPP. PRODUCING VANCOMYCIN

International Nuclear Information System (INIS)

EL-KABBANY, H.M.I.

2008-01-01

Soil samples obtained from different governments in Egypt were analyzed to determine the presence of types of antibiotic producing actinomycetes using starch-nitrite agar, starch-casein nitrate agar and Czapek's Dox agar as culture media. Different Streptomyces spp. were isolated. The Streptomyces (S.) isolates encountered were S. violochromogens, S. violaceus-nigar and S. orientalis and known as standard Vancomycin producers. The optimum conditions of S. orientalis; incubation period, initial pH and incubation temperature, were determined. In addition, physical properties; appearance, melting point, solubility, mass spectrophotometer of ultra violet (UV) and the effect of gamma rays, were also determined

Vancomycin AUC/MIC and Corresponding Troughs in a Pediatric Population.

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Kishk, Omayma A; Lardieri, Allison B; Heil, Emily L; Morgan, Jill A

2017-01-01

Adult guidelines suggest an area under the curve/minimum inhibitory concentration (AUC/MIC) > 400 corresponds to a vancomycin trough serum concentration of 15 to 20 mg/L for methicillin-resistant Staphylococcus aureus infections, but obtaining these troughs in children are difficult. The primary objective of this study was to assess the likelihood that 15 mg/kg of vancomycin every 6 hours in a child achieves an AUC/MIC > 400. This retrospective chart review included pediatric patients >2 months to AUCs were calculated four times using three pharmacokinetic methods. A total of 36 patients with 99 vancomycin trough serum concentrations were assessed. Baseline characteristics were similar between groups. For troughs in group 1 (n = 55), the probability of achieving an AUC/MIC > 400 ranged from 16.4% to 90.9% with a median trough concentration of 11.4 mg/L, while in group 2 (n = 44) the probability of achieving AUC/MIC > 400 ranged from 15.9% to 54.5% with mean trough concentration of 9.2 mg/L. The AUC/MICs were not similar between the different pharmacokinetic methods used; however, a trapezoidal equation (Method A) yielded the highest correlation coefficient (r 2 = 0.59). When dosing every 6 hours, an AUC/MIC of 400 correlated to a trough serum concentration of 11 mg/L. The probability of achieving an AUC/MIC > 400 using only a trough serum concentration and an MIC with patients receiving 15 mg/kg every 6 hours is variable based on the method used to calculate the AUC. An AUC/MIC of 400 in children correlated to a trough concentration of 11 mg/L using a trapezoidal Method to calculate AUC.

Evaluating the Relationship between Vancomycin Trough Concentration and 24-Hour Area under the Concentration-Time Curve in Neonates.

Science.gov (United States)

Tseng, Sheng-Hsuan; Lim, Chuan Poh; Chen, Qi; Tang, Cheng Cai; Kong, Sing Teang; Ho, Paul Chi-Lui

2018-04-01

Bacterial sepsis is a major cause of morbidity and mortality in neonates, especially those involving methicillin-resistant Staphylococcus aureus (MRSA). Guidelines by the Infectious Diseases Society of America recommend the vancomycin 24-h area under the concentration-time curve to MIC ratio (AUC 24 /MIC) of >400 as the best predictor of successful treatment against MRSA infections when the MIC is ≤1 mg/liter. The relationship between steady-state vancomycin trough concentrations and AUC 24 values (mg·h/liter) has not been studied in an Asian neonatal population. We conducted a retrospective chart review in Singapore hospitals and collected patient characteristics and therapeutic drug monitoring data from neonates on vancomycin therapy over a 5-year period. A one-compartment population pharmacokinetic model was built from the collected data, internally validated, and then used to assess the relationship between steady-state trough concentrations and AUC 24 A Monte Carlo simulation sensitivity analysis was also conducted. A total of 76 neonates with 429 vancomycin concentrations were included for analysis. Median (interquartile range) was 30 weeks (28 to 36 weeks) for postmenstrual age (PMA) and 1,043 g (811 to 1,919 g) for weight at the initiation of treatment. Vancomycin clearance was predicted by weight, PMA, and serum creatinine. For MRSA isolates with a vancomycin MIC of ≤1, our major finding was that the minimum steady-state trough concentration range predictive of achieving an AUC 24 /MIC of >400 was 8 to 8.9 mg/liter. Steady-state troughs within 15 to 20 mg/liter are unlikely to be necessary to achieve an AUC 24 /MIC of >400, whereas troughs within 10 to 14.9 mg/liter may be more appropriate. Copyright © 2018 American Society for Microbiology.

Novel antiseptic compound OPB-2045G shows potent bactericidal activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus both in vitro and in vivo: a pilot study in animals.

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Inoue, Yasuhide; Hagi, Akifumi; Nii, Takuya; Tsubotani, Yoshie; Nakata, Hikaru; Iwata, Koushi

2015-01-01

There is a need for new compounds to effectively treat methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). The novel monobiguanide compound 1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate (OPB-2045G) has potential bactericidal activity. We sought to elucidate the potency of OPB-2045G bactericidal activity against MRSA and VRE compared to those of chlorhexidine digluconate (CHG) and povidone iodine (PVP-I). In vitro bactericidal activity was analysed using minimum bactericidal concentration (MBC) as the index. The in vivo bactericidal efficacy of OPB-2045G was examined by determining MRSA and VRE contamination of the normal dorsal skin of mice following removal of hair. After a 3 min treatment period, the MBC of OPB-2045G was lower than that of CHG and PVP-I against standard strains and clinical isolates. Additionally, in our in vivo mouse model, the in vivo bactericidal activity of 1.5 % OPB-2045G (a clinically relevant dose) was higher than that of 0.5 % CHG and equivalent to that of 10 % PVP-I against MRSA. Similarly, the in vivo bactericidal activity of OPB-2045G was higher than that of 0.5 % CHG and 10 % PVP-I against VRE. OPB-2045G showed more potent bactericidal activity against MRSA and VRE both in vitro and in vivo compared to CHG and PVP-I, indicating that OPB-2045G may provide better protection against health care-associated infections caused by these pathogens. © 2015 The Authors.

Estudio de actinomicetos marinos aislados de la costa central del Perú y su actividad antibacteriana frente a Staphylococcus aureus Meticilina Resistentes y Enterococcus faecalis Vancomicina Resistentes Study of marine actinomycetes isolated from the central coast of Peru and their antibacterial activity against Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococcus faecalis

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Jorge León

2011-06-01

Full Text Available Objetivos. Determinar el potencial antimicrobiano de actinomicetos marinos frente a cepas S. aureus meticilino-resistentes (MRSA y E. faecalis vancomicina-resistentes (VRE. Materiales y métodos. En dos medios de cultivo se sembraron 29 cepas de actinomicetos aislados de sedimento marino. Se evaluó la capacidad inhibitoria mediante pruebas de antagonismo in vitro para MRSA y VRE. Se procesó los extractos orgánicos de tres actinomicetos seleccionados para determinar la Concentración Mínima Inhibitoria (CMI del compuesto activo. Resultados. La mayoría de los actinomicetos aislados correspondieron a un grupo homogéneo de blanco-grisáceos (62% con buen nivel de crecimiento en agar marino. Los porcentajes inhibitorios fueron superiores a 85% para ambos patógenos con halos de inhibición mayores a 69 y 78 mm de diámetro para MRSA y VRE respectivamente. Los extractos diclorometánicos de tres de los actinomicetos aislados (I-400A, B1-T61, M10-77 mostraron gran potencial inhibitorio de ambos patógenos, siendo M10-77 la cepa de actinomiceto de mayor actividad antibiótica frente a S. aureus ATCC 43300 resistente a meticilina y E. faecalis ATCC 51299 resistente a vancomicina con una Concentración Mínima Inhibitoria (CMI de 7,9 y 31,7 μg/ mL respectivamente. El análisis filogenético de la cepa M10- 77 presenta un 99% de similaridad con la especie marina Streptomyces erythrogriseus. Conclusiones. El sedimento marino de la costa central del Perú es fuente promisorio de cepas de actinomicetos con gran capacidad de producir compuestos bioactivos capaces de inhibir patógenos tipificados como multidrogo-resistentes tales como S. aureus meticilino resistentes y E. faecalis vancomicina resistentes.Objectives. To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus faecalis (VRE. Materials and

An outbreak of vancomycin-resistant Enterococcus faecium in an acute care pediatric hospital: Lessons from environmental screening and a case-control study

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Drews, Steven J; Richardson, Susan E; Wray, Rick; Freeman, Renee; Goldman, Carol; Streitenberger, Laurie; Stevens, Derek; Goia, Cristina; Kovach, Danuta; Brophy, Jason; Matlow, Anne G

2008-01-01

BACKGROUND The present study describes a vancomycin-resistant enterococci (VRE) outbreak investigation and a case-control study to identify risk factors for VRE acquisition in a tertiary care pediatric hospital. OBJECTIVE To report an outbreak investigation and a case-control study to identify risk factors for VRE colonization or infection in hospitalized children. METHODS Screening for VRE cases was performed by culture or polymerase chain reaction. A case-control study of VRE-colonized patients was undertaken. Environmental screening was performed using standard culture and susceptibility methods, with pulsed-field gel electrophoresis to determine relationships between VRE isolates. Statistical analysis was performed using SAS version 9.0 (SAS Institute Inc, USA). RESULTS Thirty-four VRE-positive cases were identified on 10 wards between February 28, 2005, and May 27, 2005. Pulsed-field gel electrophoresis analysis confirmed a single outbreak strain that was also isolated from a video game found on one affected ward. Multivariate analysis identified cephalosporin use as the major risk factor for VRE colonization. CONCLUSIONS In the present study outbreak, VRE colonization was significantly associated with cephalosporin use. Because shared recreational items and environmental surfaces may be colonized by VRE, they warrant particular attention in housekeeping protocols, particularly in pediatric institutions. PMID:19412380

Antibacterial susceptibility patterns and cross-resistance of methicillin resistant and sensitive Staphyloccus aureus isolated from the hospitalized patients in Shiraz, Iran

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Aziz Japoni

2010-10-01

Full Text Available Nosocomial infections caused by methicillin-resistant staphylococci (MRSA pose a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus including 200, 137 and 19 corresponding to MSSA, MRSA, and intermediate MRSA strains, respectively were isolated. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates (137+19 to the other tested antibiotics were also determined. S.aureus with high frequencies were isolated from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were evident. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the eight tested antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinical practices. To preserve the effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.

Linezolid Versus Vancomycin in the Empiric Treatment of Nosocomial Pneumonia: A Cost-Utility Analysis Incorporating Results from the ZEPHyR Trial.

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Collins, Curtis D; Schwemm, Ann K

2015-07-01

To examine the cost-effectiveness of vancomycin versus linezolid in the empiric treatment of nosocomial pneumonias incorporating results from a recent prospective, double-blind, multicenter, controlled trial in adults with suspected methicillin-resistant Staphylococcus aureus (MRSA) nosocomial pneumonia. A decision-analytic model examining the cost-effectiveness of linezolid versus vancomycin for the empiric treatment of nosocomial pneumonia was created. Publicly available cost, efficacy, and utility data populated relevant model variables. A probabilistic sensitivity analysis varied parameters in 10,000 Monte-Carlo simulations, and univariate sensitivity analyses assessed the impact of model uncertainties and the robustness of our conclusions. Results indicated that the cost per quality-adjusted life-year (QALY) increased 6% ($22,594 vs. $23,860) by using linezolid versus vancomycin for nosocomial pneumonia. The incremental cost per QALY gained by using linezolid over vancomycin was $6,089, and the incremental cost per life saved was $68,615 with the use of linezolid. Vancomycin dominated linezolid in the subset of patients with documented MRSA. The incremental cost per QALY gained using linezolid if no mortality benefit exists between agents or a 60-day time horizon was analyzed was $19,608,688 and $443,662, respectively. Linezolid may be a cost-effective alternative to vancomycin in the empiric treatment of patients with suspected MRSA nosocomial pneumonia; however, results of our model were highly variable on a number of important variables and assumptions including mortality differences and time frame analyzed. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Release of Gentamicin and Vancomycin from Preformed Spacers in Infected Total Hip Arthroplasties: Measurement of Concentrations and Inhibitory Activity in Patients’ Drainage Fluids and Serum

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Dario Regis

2013-01-01

Full Text Available Gentamicin (G and vancomycin (V concentrations in drainage fluids obtained from patients during the first 24 hours after implantation of antibiotic-loaded polymethylmethacrylate (PMMA spacers in two-stage revision of infected total hip arthroplasty were studied. The inhibitory activity of drainage fluids against different multiresistant clinical isolates was investigated as well. Seven hips were treated by implantation of industrial G-loaded spacers. Vancomycin was added by manually mixing with PMMA bone cement. Serum and drainage fluid samples were collected 1, 4, and 24 hours after spacer implantation. Antibiotics concentrations and drains bactericidal titer of combination were determined against multiresistant staphylococcal strains. The release of G and V from PMMA cement at the site of infection was prompt and effective. Serum levels were below the limit of detection. The local release kinetics of G and V from PMMA cement was similar, exerting a pronounced, combined inhibitory effect in the implant site. The inhibitory activity of drainage fluids showed substantial intersubject variability related to antibiotic concentrations and differed according to the pathogens tested. Gentamicin and vancomycin were released from temporary hip spacers at bactericidal concentrations, and their use in combination exerted strong inhibition against methicillin-resistant S. aureus and Coagulase Negative Staphylococci strains.

Vancomycin Dosing in Obese Patients: Special Considerations and Novel Dosing Strategies.

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Durand, Cheryl; Bylo, Mary; Howard, Brian; Belliveau, Paul

2018-06-01

To review the literature regarding vancomycin pharmacokinetics in obese patients and strategies used to improve dosing in this population. PubMed, EMBASE (1974 to November 2017), and Google Scholar searches were conducted using the search terms vancomycin, obese, obesity, pharmacokinetics, strategy, and dosing. Additional articles were selected from reference lists of selected studies. Included articles were those published in English with a primary focus on vancomycin pharmacokinetic parameters in obese patients and practical vancomycin dosing strategies, clinical experiences, or challenges of dosing vancomycin in this population. Volume of distribution and clearance are the pharmacokinetic parameters that most often affect vancomycin dosing in obese patients; both are increased in this population. Challenges with dosing in obese patients include inconsistent and inadequate dosing, observations that the obese population may not be homogeneous, and reports of an increased likelihood of supratherapeutic trough concentrations. Investigators have revised and developed dosing and monitoring protocols to address these challenges. These approaches improved target trough attainment to varying degrees. Some of the vancomycin dosing approaches provided promising results in obese patients, but there were notable differences in methods used to develop these approaches, and sample sizes were small. Although some approaches can be considered for validation in individual institutions, further research is warranted. This may include validating approaches in larger populations with narrower obesity severity ranges, investigating target attainment in indication-specific target ranges, and evaluating the impact of different dosing weights and methods of creatinine clearance calculation.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolated from clinical samples at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.

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Dilnessa, Tebelay; Bitew, Adane

2016-08-09

Staphylococcus aureus particularly MRSA strains are one of the major causes of community and hospital acquired bacterial infections. They are also becoming increasingly multi-drug resistant and have recently developed resistance to vancomycin, which has been used successfully to treat MRSA for many years. In-vitro determination of drug resistance patterns of S. aureus is critical for the selection of effective drugs for the treatment of staphylococci infections. The main aim of this study was to determine the prevalence of methicillin resistant S. aureus strains from different clinical specimens from patients referred for routine culture and sensitivity testing. A cross sectional study was conducted among 1360 participants at Yekatit 12 Hospital Medical College in Ethiopia from September 2013 to April 2014. Clinical samples from various anatomical sites of study participants were cultured on blood agar and mannitol salt agar and identified to be S. aureus by using catalase, coagulase and DNAse tests. S. aureus isolates then were screened for MRSA using 30 μg cefoxitin disc and other 11 antimicrobial drugs by disc diffusion procedure, and agar dilution and E tests for vancomycin. All S. aureus isolates examined for beta-lactamase production by employing nitrocefin. Data were analyzed using SPSS version 20 software and logistic regressions were applied to assess any association between dependent and independent variables. Of 1360 clinical specimens analyzed S. aureus was recovered from (194, 14.3 %). Rate of isolation of S. aureus with regard to clinical specimens was the highest in pus (118, 55.4 %).No S. aureus was isolated from CSF and urethral discharge. Out of 194 S. aureus isolates, (34, 17.5 %) were found out to be MRSA and the remaining (160, 82.5 %) were MSSA. Ninety eight (50.5 %) S. aureus were multi drug resistant and the highest isolates were resistant to penicillin (187, 96.4 %) and least resistant for clindamycin (23, 11.9 %) and vancomycin

The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002

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Mirović Veljko

2004-01-01

Full Text Available The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%, during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%. In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA fenotype. Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1% during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001. Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

From penicillin-streptomycin to amikacin-vancomycin: antibiotic decontamination of cardiovascular homografts in Singapore.

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Wee Ling Heng

Full Text Available BACKGROUND: In February 2012, the National Cardiovascular Homograft Bank (NCHB became the first tissue bank outside of North America to receive accreditation from the American Association of Tissue Banks. From 2008 to 2009, NCHB had been decontaminating its cardiovascular homografts with penicillin and streptomycin. The antibiotic decontamination protocol was changed in January 2010 as amikacin and vancomycin were recommended, in order to cover bacteria isolated from post-recovery and post- antibiotic incubation tissue cultures. AIM: The objective of this study is to determine the optimal incubation conditions for decontamination of homografts by evaluating the potencies of amikacin and vancomycin in different incubation conditions. Retrospective reviews of microbiological results were also performed for homografts recovered from 2008 to 2012, to compare the effectiveness of penicillin-streptomycin versus the amikacin-vancomycin regimens. METHODS: Based on microbiological assays stated in United States Pharmacopeia 31, potency of amikacin was evaluated by turbidimetric assay using Staphylococcus aureus, while vancomycin was by diffusion assay using Bacillus subtilis sporulate. Experiments were performed to investigate the potencies of individual antibiotic 6-hours post incubation at 4°C and 37°C and 4°C for 24 hours, after the results suggested that amikacin was more potent at lower temperature. FINDINGS: Tissue incubation at 4°C for 24 hours is optimal for both antibiotics, especially for amikacin, as its potency falls drastically at 37°C. CONCLUSION: The decontamination regimen of amikacin-vancomycin at 4°C for 24 hours is effective. Nevertheless, it is imperative to monitor microbiological trends closely and evaluate the efficacy of current antibiotics regimen against emerging strains of micro-organisms.

Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

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Cynthia Annes Rubião

2017-08-01

Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

Stoma-Closure-Induced Fulminant Pseudomembranous Colitis Recovered by Adjunctive Intracolic Vancomycin with Postural Change

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Yozo Suzuki

2010-05-01

Full Text Available A 67-year-old man with a history of low anterior resection and diverting loop transverse colostomy for rectal carcinoma developed fulminant pseudomembranous colitis after stoma closure. Oral administration of vancomycin at 0.5 g every 6 h and colonoscopy with intracolic vancomycin administration was unsuccessful, but continuation of intracolic vancomycin with postural change resulted in dramatic recovery. Postural change may extend the efficacy of intracolic vancomycin, and intracolic vancomycin should be considered as an option between conventional therapy and surgical intervention for pseudomembranous colitis.

EFFECT OF LINEZOLID ALONE AND IN COMBINATION WITH OTHER ANTIBIOTICS, ON METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS.

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Yehia, Hoda; El Said, Manal; Azmy, Magda; Badawy, Moushira; Mansy, Soheir; Gohar, Hamida; Madany, Nadia

2016-04-01

The prevalence of methicillin-resistant Staphyloccoccus aureus (MRSA) strains has presented a new challenge in antimicrobial medication. Linezolid is a new drug with potent activity on Gram-positive pathogens such as MRSA. The aim of the study was to investigate the in vitro activity of linezolid alone and in combination with imipenem, vancomycin or rifampicin to determine the most active therapy against MRSA strains. Twenty clinical MRSA strains were isolated from patients admitted to inpatient departments and outpatient clinics of Theodor Bilharz Research Institute. Standard strain MRSA ATCC 43300 was included as a control. The MICs of MRSA strains to linezolid, vancomycin, imipenem and rifampicin were evaluated using E test. Time-kill curve were used to assess the in vitro activity of linezolid (at 8x MIC) alone and in combination with imipenem (at 32x MIC), vancomycin or rifampicin (at 8x MIC). Scanning and transmission electron microscopy were performed to compare bacterial morphological alterations owing to the different combi- nations. Time-kill studies showed synergistic effect when linezolid combined with imipenem was tested against all the MRSA strains. Linezolid plus vancomycin or rifampicin combinations did not display any synergism or antagonism. Scanning and transmission electron microscopy observations confirmed the interactions observed in time kill experiments. Linezolid in combination with subinhibitory concentrations of imipenem can be bactericidal against MRSA strains and appears to be a promising combination for the treatment of MRSA infections. No synergistic activity was seen when the linezolid and vancomycin or rifampicin were combined. Linezolid could prevent the emergence of mutants resistant to rifampicin

Vancomycin Powder Regimen for Prevention of Surgical Site Infection in Complex Spine Surgeries.

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Van Hal, Michael; Lee, Joon; Laudermilch, Dann; Nwasike, Chinedu; Kang, James

2017-10-01

In total, 496 patients of a single surgeon cohort examining the surgical-site infection (SSI) rates with the addition of vancomycin powder in both diabetic and revision spine surgery cases. A historical control group of 652 patients were compared from the same surgeon over an earlier time period before the inception of using vancomycin powder prophylaxis. The objective of this study was to describe and compare the rates of infection in high-risk patient populations while using vancomycin powder. Vancomycin powder may not decrease an already low rate of infection. Therefore, use of vancomycin powder in high-risk patients with a higher rate of infection would potentially show benefit of vancomycin powder. In total, 496 patient charts were collected from a database of cases. Patients were included in the cohort if they had revision spinal operation or if they were diabetic. Patients in the time period July 2010 to August 2013 were included in the vancomycin protocol where 1 g of vancomycin powder was added to the wound before wound closure. Cases were considered positive if there was a positive culture or if there was sufficient clinical suspicion to treat. As a control to this cohort, 692 charts were reviewed from a earlier time period of the same surgeon and institution. In total, 28 patients of 496 (5.6%) patients in the cohort returned to the operating room for seroma, hematoma, draining wound, or infection. Sixteen of these patients (16/496, 3.2%) had a culture positive infection or were treated as an infection. This rate was significantly lower than the historical rate before the protocol. Although vancomycin does seem to be useful in decreasing SSIs, it is not a panacea. SSIs in high-risk patients were not completely eliminated by the vancomycin protocol.

Single-Dose Bone Pharmacokinetics of Vancomycin in a Porcine Implant-Associated Osteomyelitis Model

DEFF Research Database (Denmark)

Bue, Mats; Hanberg, Pelle; Koch, Janne

2018-01-01

, vancomycin bone and soft tissue penetration during infection remains unclear. In eight pigs, implant-associated osteomyelitis was induced on day 0, using a Staphylococcus aureus strain. Following administration of 1,000 mg of vancomycin on day 5, vancomycin concentrations were obtained with microdialysis...

Design and Implementation of a Novel Web-Based E-Learning Tool for Education of Health Professionals on the Antibiotic Vancomycin.

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Bond, Stuart Evan; Crowther, Shelley P; Adhikari, Suman; Chubaty, Adriana J; Yu, Ping; Borchard, Jay P; Boutlis, Craig Steven; Yeo, Wilfred Winston; Miyakis, Spiros

2017-03-30

Traditional approaches to health professional education are being challenged by increased clinical demands and decreased available time. Web-based e-learning tools offer a convenient and effective method of delivering education, particularly across multiple health care facilities. The effectiveness of this model for health professional education needs to be explored in context. The study aimed to (1) determine health professionals' experience and knowledge of clinical use of vancomycin, an antibiotic used for treatment of serious infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and (2) describe the design and implementation of a Web-based e-learning tool created to improve knowledge in this area. We conducted a study on the design and implementation of a video-enhanced, Web-based e-learning tool between April 2014 and January 2016. A Web-based survey was developed to determine prior experience and knowledge of vancomycin use among nurses, doctors, and pharmacists. The Vancomycin Interactive (VI) involved a series of video clips interspersed with question and answer scenarios, where a correct response allowed for progression. Dramatic tension and humor were used as tools to engage users. Health professionals' knowledge of clinical vancomycin use was obtained from website data; qualitative participant feedback was also collected. From the 577 knowledge survey responses, pharmacists (n=70) answered the greatest number of questions correctly (median score 4/5), followed by doctors (n=271; 3/5) and nurses (n=236; 2/5; Puser feedback from 51 participants following completion of the VI. Feedback was predominantly positive with themes of "entertaining," "engaging," and "fun" identified; however, there were some technical issues identified relating to accessibility from different operating systems and browsers. A novel Web-based e-learning tool was successfully developed combining game design principles and humor to improve user engagement. Knowledge

Antimicrobial-Resistant Enterococci in Animals and Meat: A Human Health Hazard?

DEFF Research Database (Denmark)

Hammerum, A.M.; Lester, C.H.; Heuer, Ole Eske

2010-01-01

clones predominate in certain animal species. This may suggest that antimicrobial-resistant E. faecium from animals could be regarded less hazardous to humans; however, due to their excellent ability to acquire and transfer resistance genes, E. faecium of animal origin may act as donors of antimicrobial...... resistance genes for other more virulent enterococci. For E. faecalis, the situation appears different, as similar clones of, for example, vancomycin-and gentamicin-resistant E. faecalis have been obtained from animals and from human patients. Continuous surveillance of antimicrobial resistance...... of avoparcin, gentamicin, and virginiamycin for growth promotion and therapy in food animals has lead to the emergence of vancomycin-and gentamicin-resistant enterococci and quinupristin/dalfopristin-resistant E. faecium in animals and meat. This implies a potential risk for transfer of resistance genes...

Vancomycin AUC/MIC ratio and 30-day mortality in patients with Staphylococcus aureus bacteremia.

Science.gov (United States)

Holmes, Natasha E; Turnidge, John D; Munckhof, Wendy J; Robinson, J Owen; Korman, Tony M; O'Sullivan, Matthew V N; Anderson, Tara L; Roberts, Sally A; Warren, Sanchia J C; Gao, Wei; Howden, Benjamin P; Johnson, Paul D R

2013-04-01

A ratio of the vancomycin area under the concentration-time curve to the MIC (AUC/MIC) of ≥ 400 has been associated with clinical success when treating Staphylococcus aureus pneumonia, and this target was recommended by recently published vancomycin therapeutic monitoring consensus guidelines for treating all serious S. aureus infections. Here, vancomycin serum trough levels and vancomycin AUC/MIC were evaluated in a "real-world" context by following a cohort of 182 patients with S. aureus bacteremia (SAB) and analyzing these parameters within the critical first 96 h of vancomycin therapy. The median vancomycin trough level at this time point was 19.5 mg/liter. There was a significant difference in vancomycin AUC/MIC when using broth microdilution (BMD) compared with Etest MIC (medians of 436.1 and 271.5, respectively; P AUC/MIC of ≥ 400 using BMD was not associated with lower 30-day all-cause or attributable mortality from SAB (P = 0.132 and P = 0.273, respectively). However, an alternative vancomycin AUC/MIC of >373, derived using classification and regression tree analysis, was associated with reduced mortality (P = 0.043) and remained significant in a multivariable model. This study demonstrated that we obtained vancomycin trough levels in the target therapeutic range early during the course of therapy and that obtaining a higher vancomycin AUC/MIC (in this case, >373) within 96 h was associated with reduced mortality. The MIC test method has a significant impact on vancomycin AUC/MIC estimation. Clinicians should be aware that the current target AUC/MIC of ≥ 400 was derived using the reference BMD method, so adjustments to this target need to be made when calculating AUC/MIC ratio using other MIC testing methods.

Three surveillance strategies for vancomycin-resistant enterococci in hospitalized patients: detection of colonization efficiency and a cost-effectiveness model.

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Lee, Todd A; Hacek, Donna M; Stroupe, Kevin T; Collins, Susan M; Peterson, Lance R

2005-01-01

To evaluate the cost-effectiveness and detection sensitivity associated with three active surveillance strategies for the identification of patients harboring vancomycin-resistant enterococci (VRE) to determine which is the most medically and economically useful. Culture for VRE from 200 consecutive stool specimens submitted for Clostridium difficile culture. Following this, risk factors were assessed for patients whose culture yielded VRE, and a cost-effectiveness evaluation was performed using a decision analytic model with a probabilistic analysis. A 688-bed, tertiary-care facility in Chicago, Illinois, with approximately 39,000 annual admissions, 7,000 newborn deliveries, 56,000 emergency department visits, and 115,000 home care and 265,000 outpatient visits. All stool specimens submitted to the clinical microbiology laboratory for C. difficile culture from hospital inpatients. From 200 stool samples submitted for C. difficile testing, we identified 5 patients with VRE in non-high-risk areas not screened as part of our routine patient surveillance. Medical record review revealed that all 5 had been hospitalized within the prior 2 years. Three of 5 had a history of renal impairment. The strategy that would involve screening the greatest number of patients (all those with a history of hospital admission in the prior 2 years) resulted in highest screening cost per patient admitted (dollars 2.48), lower per patient admission costs (dollars 480), and the best survival rates. An expanded VRE surveillance program that encompassed all patients hospitalized within the prior 2 years was a cost-effective screening strategy compared with a more traditional one focused on high-risk units.

Vancomycin-resistant Enterococcus faecium bacteraemia as a complication of Kayexalate (sodium polystyrene sulfonate, SPS) in sorbitol-induced ischaemic colitis.

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Cerrud-Rodriguez, Roberto Christian; Alcaraz-Alvarez, Diego; Chiong, Brian Bobby; Ahmed, Abdurhman

2017-11-09

We present the case report of an 80-year-old woman with chronic kidney disease stage G5 admitted to the hospital with fluid overload and hyperkalaemia. Sodium polystyrene sulfonate (SPS, Kayexalate) in sorbitol suspension was given orally to treat her hyperkalaemia, which precipitated an episode of SPS in sorbitol-induced ischaemic colitis with the subsequent complication of vancomycin-resistant Enterococcus (VRE) bacteraemia. SPS (Kayexalate) in sorbitol suspension has been implicated in the development of intestinal necrosis. Sorbitol, which is added as a cathartic agent to decrease the chance of faecal impaction, may be primarily responsible through several proposed mechanisms. The gold standard of diagnosis is the presence of SPS crystals in the colon biopsy. On a MEDLINE search, no previous reports of a VRE bacteraemia as a complication of biopsy-confirmed SPS in sorbitol ischaemic colitis were found. To the best of our knowledge, ours would be the first such case ever reported. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Weekly screening supports terminating nosocomial transmissions of vancomycin-resistant enterococci on an oncologic ward – a retrospective analysis

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Stefanie Kampmeier

2017-05-01

Full Text Available Abstract Background To investigate the impact of weekly screening within the bundle of infection control measures to terminate vancomycin-resistant enterococci (VRE transmissions on an oncologic ward. Methods A cluster of 12 VRE colonisation and five infections was detected on an oncologic ward between January and April 2015. Subsequently, the VRE point prevalence was detected and, as part of a the bundle of infection control strategies to terminate the VRE cluster, we isolated affected patients, performed hand hygiene training among staff on ward, increased observations by infection control specialists, intensified surface disinfection, used personal protective equipment and initiated an admission screening in May 2015. After a further nosocomial VRE infection in August 2015, a weekly screening strategy of all oncology patients on the respective ward was established while admission screening was continued. Whole genome sequencing (WGS-based typing was applied to determine the clonal relationship of isolated strains. Results Initially, 12 of 29 patients were VRE colonised; of these 10 were hospital-acquired. During May to August, on average 7 of 40 patients were detected to be VRE colonised per week during the admission screening, showing no significant decline compared to the initial situation. WGS-based typing revealed five different clusters of which three were due to vanB- and two vanA-positive enterococci. After an additional weekly screening was established, the number of colonised patients significantly declined to 1/53 and no further nosocomial cases were detected. Conclusions Weekly screening helped to differentiate between nosocomial and community-acquired VRE cases resulting in earlier infection control strategies on epidemic situations for a successful termination of nosocomial VRE transmissions.

Postcataract endophthalmitis prophylaxis using irrigation, incision hydration, and eye pressurization with vancomycin

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Schelonka LP

2015-07-01

Full Text Available Lee P Schelonka,1 Margaret A SaBell2 1Department of Opthalmology, Kaiser Permanente Lone Tree Medical Offices, Lone Tree, 2Department of Infection Control, Kaiser Permanente Lone Tree Medical Offices, Lone Tree, Denver, CO, USA Purpose: This study aimed to determine whether switching from balanced salt solution (BSS to vancomycin 20 g/mL BSS for incision hydration and eye pressurization reduces the rate of postcataract endophthalmitis.Methods: This was a patient safety/quality improvement project, including all patients undergoing cataract surgery at the Kaiser Permanente Colorado Ophthalmology Department from January 2002 to December 2014. Throughout the study, patients received vancomycin 20 µg/mL in the irrigating solution. During the baseline period from 2002 to 2005, surgeons pressurized eyes and hydrated incisions with plain BSS. During the intervention period from 2006 through 2014, surgeons switched from BSS to the vancomycin/BSS irrigating solution for eye pressurization and incision hydration.Results: A total of 57,263 cataract operations were performed by 24 surgeons at seven surgical centers: 12,400 in the baseline period and 44,863 in the intervention period. The rate of postcataract endophthalmitis declined significantly from 5/12,400 (rate: 0.4/1,000 in the baseline period to 1/44,863 (rate: 0.022/1,000 during the intervention period (odds ratio [OR]: 18.1, 95% confidence interval [CI]: 2.11–154.9; χ2=13.5, P=0.00024. Accounting for an estimated 2.05-fold risk reduction due to confounding variables, the risk reduction attributed to the intervention remained significant: (adjusted OR: 8.78, 95% CI: 1.73–44.5; χ2=10.06, P=0.0015. Since 2009, we have not experienced any cases of postcataract endophthalmitis after 32,753 operations.Conclusion: We experienced a significant reduction in postcataract endophthalmitis when we switched from BSS to the vancomycin/BSS irrigating solution for incision hydration and eye pressurization

Cost-effectiveness analysis of fidaxomicin versus vancomycin in Clostridium difficile infection.

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Nathwani, Dilip; Cornely, Oliver A; Van Engen, Anke K; Odufowora-Sita, Olatunji; Retsa, Peny; Odeyemi, Isaac A O

2014-11-01

Fidaxomicin was non-inferior to vancomycin with respect to clinical cure rates in the treatment of Clostridium difficile infections (CDIs) in two Phase III trials, but was associated with significantly fewer recurrences than vancomycin. This economic analysis investigated the cost-effectiveness of fidaxomicin compared with vancomycin in patients with severe CDI and in patients with their first CDI recurrence. A 1 year time horizon Markov model with seven health states was developed from the perspective of Scottish public healthcare providers. Model inputs for effectiveness, resource use, direct costs and utilities were obtained from published sources and a Scottish expert panel. The main model outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life year (QALY), for fidaxomicin versus vancomycin; ICERs were interpreted using willingness-to-pay thresholds of £20,000/QALY and £30,000/QALY. One-way and probabilistic sensitivity analyses were performed. Total costs were similar with fidaxomicin and vancomycin in patients with severe CDI (£14,515 and £14,344, respectively) and in patients with a first recurrence (£16,535 and £16,926, respectively). Improvements in clinical outcomes with fidaxomicin resulted in small QALY gains versus vancomycin (severe CDI, +0.010; patients with first recurrence, +0.019). Fidaxomicin was cost-effective in severe CDI (ICER £16,529/QALY) and dominant (i.e. more effective and less costly) in patients with a first recurrence. The probability that fidaxomicin was cost-effective at a willingness-to-pay threshold of £30,000/QALY was 60% for severe CDI and 68% in a first recurrence. Fidaxomicin is cost-effective in patients with severe CDI and in patients with a first CDI recurrence versus vancomycin. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

Epidemiology of vancomycin-resistant enterococci in children with acute lymphoblastic leukemia at two referral centers in Tehran, Iran: a descriptive study.

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Nateghian, A; Robinson, J L; Arjmandi, K; Vosough, P; Karimi, A; Behzad, A; Navidnia, M

2011-05-01

Risk factors for colonization with vancomycin-resistant enterococci (VRE) vary by population and locale. The objective of this study was to determine the prevalence of and risk factors for VRE colonization in children with acute lymphoblastic leukemia (ALL) in Tehran. Stools were collected from children with ALL at the Ali Asghar Children's Hospital and the Mahak Pediatric Oncology Center between March 2007 and October 2008. Demographic features and potential risk factors for VRE colonization, including duration of ALL, presence of severe neutropenia in the preceding month, receipt of antibiotics in the preceding 3 months, concurrent medical problems, days of hospitalization, and the need for intensive care since the time of diagnosis of ALL, were recorded. VRE was identified from stools in 33 of 130 children with ALL (25%). No clear risk factors were identified for VRE colonization in the current study, but there was a trend towards an increased prevalence in children admitted to the intensive care unit since their ALL diagnosis (p=0.07). The VanA genotype was found in 28 of the 33 stools (85%), with all other enterococci being VanB. The prevalence of VRE colonization in children with ALL in Tehran is high. Modifiable risk factors have not been identified. The implementation of routine surveillance for colonization and an increased emphasis on adherence to standard infection control precautions may prevent spread. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Treatment of MRSA pneumonia: Clinical and economic comparison of linezolid vs. vancomycin – a retrospective analysis of medical charts and re-imbursement data of real-life patient populations

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Wilke, Michael H.

2017-01-01

Full Text Available Objectives: To supplement the data collected in randomized clinical trials, the present study in patients with methicillin resistant (MRSA pneumonia was conducted to explore the clinical effectiveness of linezolid and vancomycin in a routine clinical setting. Further, the overall costs of the patients' stay in the intensive care unit (ICU were compared.Methods: This was a retrospective analysis of medical and reimbursement data of adult patients who were treated for MRSA pneumonia with linezolid or vancomycin. Since the subjects were not randomly assigned to treatments, propensity score adjustment was applied to reduce a potential selection bias.Results: In total, 226 patients were included; 95 received linezolid and 131 received vancomycin as initial therapy for MRSA pneumonia. Switches to another antibiotic were observed in 4 patients (4.2% receiving linezolid and in 23 patients (17.6% receiving vancomycin (logistic regression analysis; odds ratio linezolid/vancomycin: 0.183; 95% confidence interval [CI]: 0.052–0.647; p<0.01. All-cause in-hospital mortality was also lower in patients receiving linezolid (22 patients [23.2%] vs. 54 patients [41.2%] (logistic regression analysis; odds ratio linezolid/vancomycin: 0.351; 95% CI: 0.184–0.671; p<0.01. The analysis of the total costs of stay in ICU did not reveal any major differences between the two treatment groups (cost ratio linezolid/vancomycin: 1.29; 95% CI: 0.84–1.98; p=0.24.Conclusions: These findings confirm in a routine clinical setting that linezolid is a valuable therapeutic alternative to vancomycin for the treatment of MRSA pneumonia. However, prospective studies in real-life patient populations are warranted.

Antimicrobial resistance (AMR) nanomachines-mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation.

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Phillips-Jones, Mary K; Harding, Stephen E

2018-04-01

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that

Antibiotic resistance

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Marianne Frieri

2017-07-01

Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

Vancomycin added to the wash solution of the cell-saver. Effect on bacterial contamination.

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Perez-Ferrer, A; Gredilla-Díaz, E; de Vicente-Sánchez, J; Navarro-Suay, R; Gilsanz-Rodríguez, F

2017-04-01

The aim of this study is to test whether the addition of a low-dose of antibiotic (vancomycin) to the wash solution (saline) of the cell-saver reduces the incidence of bacterial contamination of the autologous red blood cell (RBCs) concentrate recovered. Experimental, randomized, double-blind, parallel group study performed on 20 consecutive patients scheduled for posterior spinal fusion surgery. Intraoperative bleeding was processed through a cell-saver: HaemoLite ® 2+, in which the RBCs were washed according to randomization group, with saline (control group) or saline+10μg/ml -1 vancomycin (vanco group). Data regarding age, weight, processed and recovered volume, blood count, blood culture, and vancomycin concentration in RBCs concentrates obtained and incidence of fever after reinfusion were collected. Processed volume was 843±403ml and recovered volume 121±29ml, with haemoglobin concentration 10.4±5.0g/dl -1 and haematocrit 29.1±15.9% (mean±SD). Recovered RBC concentrate cultures were positive for coagulase-negative Staphylococcus in 5 cases (50%) of the control group while all cultures were negative in the vanco group (P=.016). The difference between the theoretical concentration of vancomycin administered and the concentration determined in the recovered RBC concentrate was 1.31μg/ml -1 (95% CI 1.19 to 1.43; P=.074). The addition of vancomycin at a concentration of 10ug/ml -1 to the wash solution of the cell-saver achieved similar concentrations in the autologous blood concentrate recovered allowing for bacterial removal, with negative blood cultures in all cases. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Epidemiology of Resistant Microbial Strains Among Different Groups of People (Healthy, Infected and Exposed to Animals)

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2017-11-10

ESBL Producing E.Coli; ESBL Producing K.Pneumoniae; Multidrug Resistant P.Aeruginosa; Carbapenem Resistant P.Aeruginosa; Methicillin Resistant Staphylococcus Aureus (MRSA); Vancomycin (Glycopeptide) Resistant Enterococcus (VRE)

Fidaxomicin versus Vancomycin in the Treatment of Clostridium difficile Infection: Canadian Outcomes

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Christine Lee

2016-01-01

Full Text Available Background. This analysis examined the efficacy of fidaxomicin versus vancomycin in 406 Canadian patients with Clostridium difficile infection (CDI, based on data from 2 randomized, clinical trials. Methods. Patients received fidaxomicin or vancomycin 1. Patients were assessed for clinical response recurrence of infection and sustained clinical response for 28 days after treatment completion. Patients at increased risk of recurrence were subjected to subgroup analyses. Results. Clinical response rates for fidaxomicin (90.0% were noninferior to those with vancomycin (92.2%; 95% confidence interval for difference: −7.7, 3.5. However, fidaxomicin-treated patients had lower recurrence (14.4% versus 28.0%, p=0.001 and higher sustained clinical response (77.1% versus 66.3%, p=0.016. Compared with vancomycin, fidaxomicin was associated with lower recurrence rates in all subgroups, reaching statistical significance in patients with age ≥ 65 years (16.0% versus 30.9%, p=0.026, concomitant antibiotic use (16.2% versus 38.7%, p=0.036, and non-BI strains (11.8% versus 28.3%, p=0.004. Higher sustained clinical response rates were observed for fidaxomicin compared with vancomycin in all subgroups; this was statistically significant in the non-BI subgroup (82.8% versus 69.1%, p=0.021. Conclusions. In Canadian patients, fidaxomicin was superior to vancomycin in sustaining clinical response and reducing CDI recurrence.

A novel mode of regulation of the Staphylococcus aureus Vancomycin-resistance-associated response regulator VraR mediated by Stk1 protein phosphorylation.

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Canova, Marc J; Baronian, Grégory; Brelle, Solène; Cohen-Gonsaud, Martin; Bischoff, Markus; Molle, Virginie

2014-04-25

The Staphylococcus aureus Vancomycin-resistance-associated response regulator VraR is known as an important response regulator, member of the VraTSR three-component signal transduction system that modulates the expression of the cell wall stress stimulon in response to a number of different cell wall active antibiotics. Given its crucial role in regulating gene expression in response to antibiotic challenges, VraR must be tightly regulated. We report here for the first time in S. aureus convergence of two major signal transduction systems, serine/threonine protein kinase and two (three)-component systems. We demonstrate that VraR can be phosphorylated by the staphylococcal Ser/Thr protein kinase Stk1 and that phosphorylation negatively affects its DNA-binding properties. Mass spectrometric analyses and site-directed mutagenesis identified Thr106, Thr119, Thr175 and Thr178 as phosphoacceptors. A S. aureus ΔvraR mutant expressing a VraR derivative that mimics constitutive phosphorylation, VraR_Asp, still exhibited markedly decreased antibiotic resistance against different cell wall active antibiotics, when compared to the wild-type, suggesting that VraR phosphorylation may represent a novel and presumably more general mechanism of regulation of the two (three)-component systems in staphylococci. Copyright © 2014 Elsevier Inc. All rights reserved.

Methicillin-resistant Staphylococcus aureus in Zimbabwe ...

African Journals Online (AJOL)

Resistance was high for most widely used drugs in Zimbabwe with high sensitivity to vancomycin, linezolid and teicoplanin. Conclusion: Although there are no recent reports in the literature of the presence of MRSA in Zimbabwe, this study documented a 7.0% prevalence. Resistance to common antibiotics is high and ...

Long-term Conventionally Dosed Vancomycin Therapy In Patients With Orthopaedic Implant-related Infections Seems As Effective And Safe As Long-term Penicillin Or Clindamycin Therapy. A Retrospective Cohort Study Of 103 Patients.

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Aleman, Jacomien; Moojen, Dirk Jan F; van Ogtrop, Marc L; Poolman, Rudolf W; Franssen, Eric J F

2018-01-01

Objectives : Antimicrobial therapy is one of the cornerstones of orthopaedic implant-related infections (OIRI) treatment. Infections with Gram-positive bacteria are often treated with vancomycin, penicillin or clindamycin. A recent IDSA guideline suggests increasing the dose of vancomycin to increase the trough vancomycin target serum concentrations. This is deemed necessary because of an observed decrease in vancomycin susceptibility among Gram-positive bacteria. However, elevated vancomycin concentrations are correlated with the risk of nephrotoxicity, especially with prolonged therapy. Compared to most countries, rates of resistance against antibiotics among bacteria in the Netherlands are lower for currently available antibiotics, therefore lower target concentrations of vancomycin are probably efficacious for the treatment of infections. In this study we evaluated the efficacy and safety of long-term conventionally dosed vancomycin therapy, as an initial therapy for OIRI, and compared this with long-term penicillin and clindamycin therapy, as initial therapy, in patients with Gram-positive orthopaedic implant-related infections. Methods : A retrospective, observational study was conducted in 103 adult patients treated for OIRI, with vancomycin, penicillin or clindamycin for at least 10 days. The target trough serum concentration of vancomycin was 10-15 mg/l. Results : 74% of our patients were treated successfully with vancomycin, as initial therapy, (no reinfection within 1 year) versus 55% of our patients treated with either an antibiotic of the penicillin class (mostly flucloxacillin) or clindamycin (p=0.08), as initial therapy. For patients treated with vancomycin we observed a serum creatinine increase of 6 μmol/l, for patients treated with either an antibiotic of the penicillin class or clindamycin the serum creatinine increase was 4 μmol/l (p=0.395). Conclusions : In our population of patients with OIRI long-term treatment with conventionally dosed

The effectiveness of a single-stage versus traditional three-staged protocol of hospital disinfection at eradicating vancomycin-resistant Enterococci from frequently touched surfaces.

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Friedman, N Deborah; Walton, Aaron L; Boyd, Sarah; Tremonti, Christopher; Low, Jillian; Styles, Kaylene; Harris, Owen; Alfredson, David; Athan, Eugene

2013-03-01

Environmental contamination is a reservoir for vancomycin-resistant enterococcus (VRE) in hospitals. Environmental sampling of surfaces was undertaken anytime before disinfection and 1 hour after disinfection utilizing a sodium dichloroisocyanurate-based, 3-staged protocol (phase 1) or benzalkonium chloride-based, single-stage clean (phase 2). VRE colonization and infection rates are presented from 2010 to 2011, and audits of cleaning completeness were also analyzed. Environmental samples collected before disinfection were significantly more likely to be contaminated with VRE during phase 1 than phase 2: 25.2% versus 4.6%, respectively; odds ratio (OR), 7.01 (P benzalkonium chloride-based product for disinfection. This reduction in VRE may be due to a new disinfection product, more attention to the thoroughness of cleaning, or other supplementary efforts in our institution. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Analysis of antibiotic resistance pattern of S. aureus strains isolated from the Orthopedics-Traumatology Section of "Sf. Spiridon" Clinical Emergency Hospital, Iaşi.

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Tucaliuc, D; Alexa, O; Tuchiluş, Cristina Gabriela; Ursu, Ramona Gabriela; Tucaliuc, Elena Simona; Iancu, Luminiţa Smaranda

2014-01-01

The retrospective analysis of antibiotic sensibility of S. aureus strains isolated from infected patients from the Orthopedics-Traumatology Clinic of "Sf. Spiridon" Clinical Emergency Hospital, Iaşi during January 2003-December 2013, in view of determining the evolution trend of the resistance phenomenon and of pinpointing the most useful treatment for these strains. The antibiotic sensitivity test was carried out using two methods: diffusimetric-Kirby-Bauer and the MIC determination by E-test (for the strains isolated in 2013); the interpretation of the sensitivity was made in a standardized manner, in compliance with the CLSI (Clinical and Laboratory Standards Institute) standard for antibiotics testing in force. The sensitivity testing for beta-lactams proved that during the 11 years of the study, the average value of the frequency of resistant strains was of 41.59% +/- 8.68. The highest frequency of MRSA (Methicillin Restant S. aureus) strains was noticed in 2012 (58.6%), followed by 2004 (50.7%). Even if in 2013 it dropped to 38.9%, the trend calculated for 2003-2013 is slightly rising (y = 0.0073x + 0.372). Out of the total of 495 S. aureus strains that were isolated, 164 (33.13%) were completely sensitive to the tested antibiotics and 26 (5.25%) were resistant only to beta-lactams. The other MRSA strains associated multiple resistance and MIC for vancomycin varied between 0.5-2 mg/ml. Two strains whose MIC was of 0.5 mg/ml were sensitive to most classes of tested antibiotics, including beta-lactams, except for macrolides (erythromycin), and the strain whose MIC was of 2 mg/ml, was resistant to all classes of tested antibiotics, except for glycopeptides and oxazolidiones. The other tested strains had a MIC for vancomycin equal to 1 mg/ml. Due to the fact that there are infections with SAMR strains in a rather worrying percentage (53.9%) that are resistant to the other classes of antibiotics, the only therapeutic solution being the vancomycin treatment, its

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage.

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Haakensen, Monique; Vickers, David M; Ziola, Barry

2009-09-07

Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol). Use of antimicrobial compounds (e.g., hop-compounds, Penicillin) by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Lactic acid bacteria susceptibility test broth medium (LSM) used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

Evolution of multidrug resistance during Staphylococcus aureus infection involves mutation of the essential two component regulator WalKR.

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Benjamin P Howden

2011-11-01

Full Text Available Antimicrobial resistance in Staphylococcus aureus is a major public health threat, compounded by emergence of strains with resistance to vancomycin and daptomycin, both last line antimicrobials. Here we have performed high throughput DNA sequencing and comparative genomics for five clinical pairs of vancomycin-susceptible (VSSA and vancomycin-intermediate ST239 S. aureus (VISA; each pair isolated before and after vancomycin treatment failure. These comparisons revealed a frequent pattern of mutation among the VISA strains within the essential walKR two-component regulatory locus involved in control of cell wall metabolism. We then conducted bi-directional allelic exchange experiments in our clinical VSSA and VISA strains and showed that single nucleotide substitutions within either walK or walR lead to co-resistance to vancomycin and daptomycin, and caused the typical cell wall thickening observed in resistant clinical isolates. Ion Torrent genome sequencing confirmed no additional regulatory mutations had been introduced into either the walR or walK VISA mutants during the allelic exchange process. However, two potential compensatory mutations were detected within putative transport genes for the walK mutant. The minimal genetic changes in either walK or walR also attenuated virulence, reduced biofilm formation, and led to consistent transcriptional changes that suggest an important role for this regulator in control of central metabolism. This study highlights the dramatic impacts of single mutations that arise during persistent S. aureus infections and demonstrates the role played by walKR to increase drug resistance, control metabolism and alter the virulence potential of this pathogen.

One-pot synthesis of multifunctional nanoscale metal-organic frameworks as an effective antibacterial agent against multidrug-resistant Staphylococcus aureus

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Chowdhuri, Angshuman Ray; Das, Balaram; Kumar, Amit; Tripathy, Satyajit; Roy, Somenath; Sahu, Sumanta Kumar

2017-03-01

Drug-resistant bacteria are an increasingly serious threat to global public health. In particular, infections from multidrug-resistant (MDR) Gram-positive bacteria (i.e. Staphylococcus aureus) are growing global health concerns. In this work, we report the first use of nanoscale metal-organic frameworks (NMOFs) coencapsulating an antibiotic (vancomycin) and targeting ligand (folic acid) in one pot to enhance therapeutic efficacy against MDR S. aureus. Zeolitic imidazolate framework (ZIF-8) NMOFs, which have globular morphologies coencapsulating vancomycin and folic acid, are characterized by transmission electron microscopy, field-emission scanning electron microscopy, powder x-ray diffraction, ulltraviolet-visible spectroscopy, and dynamic light-scattering techniques. We determined that the presence of folic acid on the surface of the NMOFs is significant in the sense of effective uptake by MDR S. aureus through endocytosis. The functionalized NMOFs transport vancomycin across the cell wall of MDR S. aureus and enhance antibacterial activity, which has been confirmed from studies of the minimum inhibitory concentration, minimum bactericidal concentration, cytotoxicity of bacterial cells, and generation of reactive oxygen species. This work shows that functionalized NMOFs hold great promise for effective treatment of MDR S. aureus.

Antibiotic susceptibility pattern of staphylococcus aureus and methicillin-resistant staphylococcus aureus in a tertiary care hospital

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CP Bhatt

2014-04-01

Full Text Available Background: Methicillin resistant Staphylococcus aureushas emerged as one of the most important nosocomial pathogens. It invokes a tremendous financial burden and enhanced morbidity and mortality due to difficult to treat systemic infections.Aim of this study was to determine antibiotic susceptibility pattern of Staphylococcus aureus and Methicillin resistant Staphylococcus aureus. Materials and Methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: Out of 1173 samples received for microbiological examination, 100 were found to be S. aureus with 19% cases were Methicillin resistant Staphylococcus aureus (MRSA. Fourteen MRSA were found from inpatient and 5 were from outpatient. MRSA was found higher in female than male and maximum number (31.5% was found in age group 0-10 years. Staphylococcus aureus was 100% sensitive to Vancomycin followed by Amikacin (90%, Gentamycin (83%, and tetracycline (81%. On urine isolates Nitrofurantoin(91.6% was drug of choice. All the isolates were resistant to Penicillin G. In case of Methicillin resistant Staphylococcus aureus showed 100% sensitive to Vancomycin followed by Amikacin (84.2%, Tetracycline (63.1%, Ciprofloxacin (42% and Gentamycin (36.8%. Among urine isolates Nitrofutantoin showed 87.5% sensitive followed by Norfloxacin (75%. Conclusion: Methicillin resistant Staphylococcus aureus was found 19% of Staphylococcus aureus isolates. It was most common in females, hospitalized patients and young age group. Vancomycin seems to be drug of choice followed by Amikacin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10297 Journal of Pathology of Nepal (2014 Vol. 4, 548-551   

Randomized prospective study comparing vancomycin with teicoplanin in the treatment of infections associated with Hickman catheters.

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Smith, S R; Cheesbrough, J; Spearing, R; Davies, J M

1989-08-01

In 72 episodes of suspected or proven Hickman-catheter-associated infection occurring in 59 patients with various hematological disorders, patients were assigned to treatment with either vancomycin or teicoplanin in a randomized nonblinded prospective study. Of 60 episodes evaluable for response, 28 were treated with vancomycin and 32 were treated with teicoplanin. Sixteen infective episodes were microbiologically documented in the vancomycin group, and twenty-one were microbiologically documented in the teicoplanin group. Microbiologically and clinically documented infections treated with vancomycin had an 80% response rate, compared with a 69% response rate for those treated with teicoplanin (P = 0.316). Adverse events occurred in nine (25%) of the episodes in the vancomycin group, compared with three (8%) in the teicoplanin group (P = 0.044). Teicoplanin may provide an effective alternative to vancomycin in the treatment of Hickman-catheter-associated infection in patients with hematological malignancies.

Surveillance for vancomycin resistant enterococci in a tertiary ...

African Journals Online (AJOL)

Three were resistant to Ampicillin and nine to Ciprofloxacin but all were susceptible to Linezolid. High-level resistance to Gentamicin was found in four VRE isolates. Conclusion: There is a low prevalence of VRE in Lagos University Teaching Hospital which may be spreading among patients in affected wards. Keywords: ...

Mechanisms of antibiotic resistance in Staphylococcus aureus.

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Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

2007-06-01

Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

Evaluating the Effect of a Web-Based E-Learning Tool for Health Professional Education on Clinical Vancomycin Use: Comparative Study.

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Bond, Stuart Evan; Crowther, Shelley P; Adhikari, Suman; Chubaty, Adriana J; Yu, Ping; Borchard, Jay P; Boutlis, Craig Steven; Yeo, Wilfred Winston; Miyakis, Spiros

2018-02-26

Internet-based learning for health professional education is increasing. It offers advantages over traditional learning approaches, as it enables learning to be completed at a time convenient to the user and improves access where facilities are geographically disparate. We developed and implemented the Vancomycin Interactive (VI) e-learning tool to improve knowledge on the clinical use of the antibiotic vancomycin, which is commonly used for treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). The aims of this study were to evaluate the effect of the VI e-learning tool on (1) survey knowledge scores and (2) clinical use of vancomycin among health professionals. We conducted a comparative pre-post intervention study across the 14 hospitals of two health districts in New South Wales, Australia. A knowledge survey was completed by nurses, doctors, and pharmacists before and after release of a Web-based e-learning tool. Survey scores were compared with those obtained following traditional education in the form of an email intervention. Survey questions related to dosing, administration, and monitoring of vancomycin. Outcome measures were survey knowledge scores among the three health professional groups, vancomycin plasma trough levels, and vancomycin approvals recorded on a computerized clinical decision support system. Survey response rates were low at 26.87% (577/2147) preintervention and 8.24% (177/2147) postintervention. The VI was associated with an increase in knowledge scores (maximum score=5) among nurses (median 2, IQR 1-2 to median 2, IQR 1-3; Pe-learning tool achieved higher overall scores than those who did not (Pe-learning tool was not shown to be significantly more effective than the comparator email in the clinical use of vancomycin, as measured by plasma levels within the therapeutic range. The e-learning tool was associated with improved knowledge scores among nurses, whereas the comparator email was associated with

Berberine blocks the relapse of Clostridium difficile infection in C57BL/6 mice after standard vancomycin treatment.

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Lv, Zhi; Peng, Guoli; Liu, Weihua; Xu, Hufeng; Su, JianRong

2015-07-01

Vancomycin is a preferred antibiotic for treating Clostridium difficile infection (CDI) and has been associated with a rate of recurrence of CDI of as high as 20% in treated patients. Recent studies have suggested that berberine, an alternative medical therapy for gastroenteritis and diarrhea, exhibits several beneficial effects, including induction of anti-inflammatory responses and restoration of the intestinal barrier function. This study investigated the therapeutic effects of berberine on preventing CDI relapse and restoring the gut microbiota in a mouse model. Berberine was administered through gavage to C57BL/6 mice with established CDI-induced intestinal injury and colitis. The disease activity index (DAI), mean relative weight, histopathology scores, and levels of toxins A and B in fecal samples were measured. An Illumina sequencing-based analysis of 16S rRNA genes was used to determine the overall structural change in the microbiota in the mouse ileocecum. Berberine administration significantly promoted the restoration of the intestinal microbiota by inhibiting the expansion of members of the family Enterobacteriaceae and counteracting the side effects of vancomycin treatment. Therapy consisting of vancomycin and berberine combined prevented weight loss, improved the DAI and the histopathology scores, and effectively decreased the mortality rate. Berberine prevented CDIs from relapsing and significantly improved survival in the mouse model of CDI. Our data indicate that a combination of berberine and vancomycin is more effective than vancomycin alone for treating CDI. One of the possible mechanisms by which berberine prevents a CDI relapse is through modulation of the gut microbiota. Although this conclusion was generated in the case of the mouse model, use of the combination of vancomycin and berberine and represent a novel therapeutic approach targeting CDI. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Currently used dosage regimens of vancomycin fail to achieve therapeutic levels in approximately 40% of intensive care unit patients.

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Obara, Vitor Yuzo; Zacas, Carolina Petrus; Carrilho, Claudia Maria Dantas de Maio; Delfino, Vinicius Daher Alvares

2016-01-01

This study aimed to assess whether currently used dosages of vancomycin for treatment of serious gram-positive bacterial infections in intensive care unit patients provided initial therapeutic vancomycin trough levels and to examine possible factors associated with the presence of adequate initial vancomycin trough levels in these patients. A prospective descriptive study with convenience sampling was performed. Nursing note and medical record data were collected from September 2013 to July 2014 for patients who met inclusion criteria. Eighty-three patients were included. Initial vancomycin trough levels were obtained immediately before vancomycin fourth dose. Acute kidney injury was defined as an increase of at least 0.3mg/dL in serum creatinine within 48 hours. Considering vancomycin trough levels recommended for serious gram-positive infection treatment (15 - 20µg/mL), patients were categorized as presenting with low, adequate, and high vancomycin trough levels (35 [42.2%], 18 [21.7%], and 30 [36.1%] patients, respectively). Acute kidney injury patients had significantly greater vancomycin trough levels (p = 0.0055, with significance for a trend, p = 0.0023). Surprisingly, more than 40% of the patients did not reach an effective initial vancomycin trough level. Studies on pharmacokinetic and dosage regimens of vancomycin in intensive care unit patients are necessary to circumvent this high proportion of failures to obtain adequate initial vancomycin trough levels. Vancomycin use without trough serum level monitoring in critically ill patients should be discouraged.

Isolation and Host Range of Bacteriophage with Lytic Activity against Methicillin-Resistant Staphylococcus aureus and Potential Use as a Fomite Decontaminant.

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Kyle C Jensen

Full Text Available Staphylococcus aureus (SA is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future. New MRSA treatments are clearly needed. Bacteriophages (phages are viruses that infect bacteria, commonly resulting in death of the host bacterial cell. Phage therapy entails the use of phage to treat or prevent bacterial infections. In this study, 12 phages were isolated that can replicate in human SA and/or MRSA isolates as a potential way to control these infections. 5 phage were discovered through mitomycin C induction of prophage and 7 others as extracellular viruses. Primary SA strains were also isolated from environmental sources to be used as tools for phage discovery and isolation as well as to examine the target cell host range of the phage isolates by spot testing. Primary isolates were tested for susceptibility to oxacillin in order to determine which were MRSA. Experiments were performed to assess the host range and killing potential of newly discovered phage, and significant reductions in bacterial load were detected. We explored the utility of some phage to decontaminate fomites (glass and cloth and found a significant reduction in colony forming units of MRSA following phage treatment, including tests of a phage cocktail against a cocktail of MRSA isolates. Our findings suggest that phage treatment can be used as an effective tool to decontaminate human MRSA from both hard surfaces and fabrics.

Association between Accessory Gene Regulator Polymorphism and Mortality among Critically Ill Patients Receiving Vancomycin for Nosocomial MRSA Bacteremia: A Cohort Study

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Angélica Cechinel

2016-01-01

Full Text Available Background. Polymorphism of the accessory gene regulator group II (agr in methicillin-resistant Staphylococcus aureus (MRSA is predictive of vancomycin failure therapy. Nevertheless, the impact of group II agr expression on mortality of patients with severe MRSA infections is not well established. Objective. The goal of our study was to evaluate the association between agr polymorphism and all-cause in-hospital mortality among critically ill patients receiving vancomycin for nosocomial MRSA bacteremia. Methods. All patients with documented bacteremia by MRSA requiring treatment in the ICU between May 2009 and November 2011 were included in the study. Cox proportional hazards regression was performed to evaluate whether agr polymorphism was associated with all-cause in-hospital mortality. Covariates included age, APACHE II score, initial C-reactive protein plasma levels, initial serum creatinine levels, vancomycin minimum inhibitory concentration, vancomycin serum levels, and time to effective antibiotic administration. Results. The prevalence of group I and group II agr expression was 52.4% and 47.6%, respectively. Bacteremia by MRSA group III or group IV agr was not documented in our patients. The mean APACHE II of the study population was 24.3 (standard deviation 8.5. The overall cohort mortality was 66.6% (14 patients. After multivariate analysis, initial plasma C-reactive protein levels (P=0.01, initial serum creatinine levels (P=0.008, and expression of group II agr (P=0.006 were positively associated with all-cause in-hospital mortality. Patients with bacteremia by MRSA with group II agr expression had their risk of death increased by 12.6 times when compared with those with bacteremia by MRSA with group I agr expression. Conclusion. Group II agr polymorphism is associated with an increase in mortality in critically ill patients with bacteremia by MRSA treated with vancomycin.

Simple and rapid quantification of vancomycin in serum, urine and peritoneal/pleural effusion via UHPLC-MS/MS applicable to personalized antibiotic dosing research.

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Javorska, Lenka; Krcmova, Lenka Kujovska; Solich, Petr; Kaska, Milan

2017-08-05

Management of the therapy of life-threatening bacterial infection is extremely based on an optimal antibiotic treatment. Achieving the correct vancomycin dosage in blood and target tissues can be complicated in special situations, e.g., where large fluid sequestration and/or acute renal failure occur. A UHPLC-MS/MS method operating in electrospray (ESI) positive ion mode was applied for the determination of vancomycin in serum, urine and peritoneal/pleural effusion. Sample pretreatment was composed of dilution and simple protein precipitation where only a small volume (50μL) of serum, urine or peritoneal/pleural effusion was required. The separation of vancomycin was performed on a Meteoric Core C18 BIO column (100×4.6mm, 2.7μm) by gradient elution with 0.1% formic acid in water and acetonitrile. The total time of analysis was 4.5min. The method was found to be linear in the range of 2-60μM (or 0.5-10μM) for serum, 0.27-10μM (or 2-60μM) for peritoneal/pleural effusion and 25-300μM for urine, which was adequate for the determination of vancomycin in patient samples. The intra- and inter-day precision was below 8% RSD, and accuracy was from 89 to 104%. The UHPLC/MS-MS method offers a fast and reliable approach to determine vancomycin concentrations in three different human body fluid samples (serum, urine and peritoneal/pleural effusion) with a simple sample pretreatment that was the same for all selected specimens. This method should be applicable to large sample series in clinical (pharmacokinetic/pharmacodynamic) studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Avaliação da sensibilidade a antimicrobianos de 87 amostras clínicas de enterococos resistentes à vancomicina Antimicrobial susceptibility testing of 87 clinical isolates of vancomycin-resistant enterococci

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I.H. Saraiva

1997-09-01

tratamento de infecções causadas por enterococos multirresistentes ainda é um desafio, e vários esquemas já vêm sendo propostos na literatura. São necessários, no entanto, mais trabalhos analisando a efetividade clínica dessas combinações de antibióticos antes que recomendações definitivas possam ser feitas.OBJECTIVES. 1 To evaluate the antimicrobial susceptibility pattern of vancomycin-resistant enterococci to the antimicrobial agents that are commonly used to treat enterococci infections and to some alternative drugs. 2 To evaluate the accuracy of E test for susceptibility testing enterococci. MATERIAL AND METHOD. We evaluated 87 clinical VRE isolates that were selected from a previous study which analyzed 1936 clinical isolates collected and processed in 97 US medical centers in the last quarter of 1992. The isolates were identified to the species level by using the API 20S System, the Vitek gram-positive identification cards and a modified version of the conventional method proposed by Facklam and Collins. The in vitro susceptibility testing was performed by broth microdilution, E test and disk diffusion methods, following the criteria described by the National Committee for Clinical Laboratory Standards (NCCLS. The VRE isolates were tested against antimicrobial agents commonly used to treat enterococci infections (vancomycin, teicoplanin, ampicillin, penicillin, gentamicin and streptomycin and against ten potential alternative drugs (chloramphenicol, doxycycline, sparfloxacin, ciprofloxacin, clinafloxacin, erythromycin, spectinomycin, trospectomycin, trimetoprim-sulfametoxazol and novobiocin. RESULTS. Our results showed a high rate of resistance to ampicillin and penicillin (86%. High level resistance to gentamicin and streptomycin was demonstrated by 82% and 85% respectively. Although teicoplanin and vancomycin belong to the same antibiotic group (glycopeptide, 29% of VRE were susceptible to teicoplanin. Among the alternative drugs, trospectomycin

Clinical Utility and Safety of a Model-Based Patient-Tailored Dose of Vancomycin in Neonates.

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Leroux, Stéphanie; Jacqz-Aigrain, Evelyne; Biran, Valérie; Lopez, Emmanuel; Madeleneau, Doriane; Wallon, Camille; Zana-Taïeb, Elodie; Virlouvet, Anne-Laure; Rioualen, Stéphane; Zhao, Wei

2016-04-01

Pharmacokinetic modeling has often been applied to evaluate vancomycin pharmacokinetics in neonates. However, clinical application of the model-based personalized vancomycin therapy is still limited. The objective of the present study was to evaluate the clinical utility and safety of a model-based patient-tailored dose of vancomycin in neonates. A model-based vancomycin dosing calculator, developed from a population pharmacokinetic study, has been integrated into the routine clinical care in 3 neonatal intensive care units (Robert Debré, Cochin Port Royal, and Clocheville hospitals) between 2012 and 2014. The target attainment rate, defined as the percentage of patients with a first therapeutic drug monitoring serum vancomycin concentration achieving the target window of 15 to 25 mg/liter, was selected as an endpoint for evaluating the clinical utility. The safety evaluation was focused on nephrotoxicity. The clinical application of the model-based patient-tailored dose of vancomycin has been demonstrated in 190 neonates. The mean (standard deviation) gestational and postnatal ages of the study population were 31.1 (4.9) weeks and 16.7 (21.7) days, respectively. The target attainment rate increased from 41% to 72% without any case of vancomycin-related nephrotoxicity. This proof-of-concept study provides evidence for integrating model-based antimicrobial therapy in neonatal routine care. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Resistance of Staphylococcus aureus to antimicrobial agents in Ethiopia: a meta-analysis.

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Deyno, Serawit; Fekadu, Sintayehu; Astatkie, Ayalew

2017-01-01

Emergence of antimicrobial resistance by Staphylococcus aureus has limited treatment options against its infections. The purpose of this study was to determine the pooled prevalence of resistance to different antimicrobial agents by S. aureus in Ethiopia. Web-based search was conducted in the databases of PubMed, Google Scholar, Hinari, Scopus and the Directory of Open Access Journals (DOAJ) to identify potentially eligible published studies. Required data were extracted and entered into Excel spread sheet. Statistical analyses were performed using Stata version 13.0. The metaprop Stata command was used to pool prevalence values. Twenty-one separate meta-analysis were done to estimate the pooled prevalence of the resistance of S. aureus to twenty-one different antimicrobial agents. Heterogeneity among the studies was assessed using the I 2 statistic and chi-square test. Publication bias was assessed using Egger's test. Because of significant heterogeneity amongst the studies, the random effects model was used to pool prevalence values. The electronic database search yielded 1317 studies among which 45 studies met our inclusion criteria. Our analyses demonstrated very high level of resistance to amoxicillin (77% [95% confidence interval (CI): 68%, 0.85%]), penicillin (76% [95% CI: 67%, 84%]), ampicillin (75% [95% CI: 65%, 85%]), tetracycline (62% [95% CI: 55%, 68%]), methicillin (47% [95% CI: 33%, 61%]), cotrimoxaziole (47% [95% CI: 40%, 55%]), doxycycline (43% [95% CI: 26%, 60%]), and erythromycin (41% [95% CI: 29%, 54%]). Relatively low prevalence of resistance was observed with kanamycin (14% [95% CI: 5%, 25%]) and ciprofloxacin (19% [95% CI: 13%, 26%]). The resistance level to vancomycin is 11% 995% CI: (4%, 20%). High heterogeneity was observed for each of the meta-analysis performed (I 2 ranging from 79.36% to 95.93%; all p -values ≤0.01). Eggers' test did not show a significant publication bias for all antimicrobial agents except for erythromycin and

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage

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Ziola Barry

2009-09-01

Full Text Available Abstract Background Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol. Use of antimicrobial compounds (e.g., hop-compounds, Penicillin by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Results Lactic acid bacteria susceptibility test broth medium (LSM used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Conclusion Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

TOC-39, a novel parenteral broad-spectrum cephalosporin with excellent activity against methicillin-resistant Staphylococcus aureus.

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Hanaki, H; Akagi, H; Masaru, Y; Otani, T; Hyodo, A; Hiramatsu, K

1995-01-01

TOC-39, a new parenteral cephalosporin, is a hydroxyimino-type cephem antibiotic with vinylthio-pyridyl moiety at the 3 position. TOC-39 was evaluated for antibacterial activity against various clinically isolated strains. TOC-39 had excellent activity, stronger than that of methicillin, oxacillin, the cephalosporins tested, imipenem, gentamicin, minocycline, tobramycin, ofloxacin, and ciprofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and had an MIC comparable to that of vancomycin (the MICs of TOC-39 and vancomycin for 90% of the strains tested were 3.13 and 1.56 micrograms/ml, respectively). Against Enterococcus faecalis strains, which are resistant to cephalosporins, TOC-39 was twice as active as ampicillin. Against methicillin-susceptible S. aureus, coagulase-negative Staphylococcus spp., and Streptococcus pneumoniae, TOC-39 was twice as active as or more active than cefotiam, ceftazidime, flomoxef, and cefpirome. Against Streptococcus pyogenes, TOC-39 was superior to cefotiam, ceftazidime, and flomoxef and was similar to cefpirome. In addition, the activity of TOC-39 was equal to or greater than that of cefotiam, ceftazidime, flomoxef, and cefpirome against Haemophilus influenzae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii. In terms of bactericidal effect against MRSA, TOC-39 was superior to vancomycin. No mutant resistant to TOC-39 or vancomycin was obtained from susceptible MRSA strains. In murine systemic infection models, TOC-39 showed potent activity against S. aureus and E. coli. Against highly MRSA, the activity of TOC-39 was comparable to that of vancomycin. PMID:7625799

Impact of an Environmental Cleaning Intervention on the Presence of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on Surfaces in Intensive Care Unit Rooms

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Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.

2009-01-01

OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus

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Renata Albuquerque COSTA

2015-06-01

Full Text Available The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg, ampicillin (Amp 10 µg, penicillin G (Pen 10U, ciprofloxacin (Cip 5 µg, chloramphenicol (Chl 30 µg, nalidixic acid (Nal 30 µg, tetracycline (Tet 30 µg, vancomycin (Van 30 µg and erythromycin (Ery 15 µg. All strains were resistant to at least one antibiotic, and 85 (97.7% were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46. Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.

Controlled release of vancomycin from thin sol-gel films on implant surfaces successfully controls osteomyelitis.

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Adams, Christopher S; Antoci, Valentin; Harrison, Gerald; Patal, Payal; Freeman, Terry A; Shapiro, Irving M; Parvizi, Javad; Hickok, Noreen J; Radin, Shula; Ducheyne, Paul

2009-06-01

Peri-prosthetic infection remains a serious complication of joint replacement surgery. Herein, we demonstrate that a vancomycin-containing sol-gel film on Ti alloy rods can successfully treat bacterial infections in an animal model. The vancomycin-containing sol-gel films exhibited predictable release kinetics, while significantly inhibiting S. aureus adhesion. When evaluated in a rat osteomyelitis model, microbiological analysis indicated that the vancomycin-containing sol-gel film caused a profound decrease in S. aureus number. Radiologically, while the control side showed extensive bone degradation, including abscesses and an extensive periosteal reaction, rods coated with the vancomycin-containing sol-gel film resulted in minimal signs of infection. MicroCT analysis confirmed the radiological results, while demonstrating that the vancomycin-containing sol-gel film significantly protected dense bone from resorption and minimized remodeling. These results clearly demonstrate that this novel thin sol-gel technology can be used for the targeted delivery of antibiotics for the treatment of periprosthetic as well as other bone infections. Copyright 2008 Orthopaedic Research Society

Prophylactic Vancomycin Drops Reduce the Severity of Early Bacterial Keratitis in Keratoprosthesis

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Konstantopoulos, Aris; Tan, Xiao Wei; Goh, Gwendoline Tze Wei; Saraswathi, Padmanabhan; Chen, Liyan; Nyein, Chan Lwin; Zhou, Lei; Beuerman, Roger; Tan, Donald Tiang Hwee; Mehta, Jod

2015-01-01

Background Artificial cornea transplantation, keratoprosthesis, improves vision for patients at high risk of failure with human cadaveric cornea. However, post-operative infection can cause visual loss and implant extrusion in 3.2–17% of eyes. Long-term vancomycin drops are recommended following keratoprosthesis to prevent bacterial keratitis. Evidence, though, in support of this practice is poor. We investigated whether prophylactic vancomycin drops prevented bacterial keratitis in an animal keratoprosthesis model. Methodology Twenty-three rabbits were assigned either to a prophylactic group (n = 13) that received vancomycin 1.4% drops 5 times/day from keratoprosthesis implantation to sacrifice, or a non-prophylactic group (n = 10) that received no drops. All rabbits had Staphylococcus aureus inoculation into the cornea at 7–12 days post-implantation and were sacrificed at predetermined time-points. Prophylactic and non-prophylactic groups were compared with slit-lamp photography (SLP), anterior segment optical coherence tomography (AS-OCT), and histology, immunohistochemistry and bacterial quantification of excised corneas. Corneal vancomycin pharmacokinetics were studied in 8 additional rabbits. Results On day 1 post-inoculation, the median SLP score and mean±SEM AS-OCT corneal thickness (CT) were greater in the non-prophylactic than the prophylactic group (11 vs. 1, p = 0.049 and 486.9±61.2 vs. 327.4±37.1 μm, p = 0.029 respectively). On days 2 and 4, SLP scores and CT were not significantly different. Immunohistochemistry showed a greater CD11b+ve/non-CD11b+ve cell ratio in the non-prophylactic group (1.45 vs. 0.71) on day 2. Bacterial counts were not significantly different between the two groups. Corneal vancomycin concentration (2.835±0.383 μg/ml) exceeded minimum inhibitory concentration (MIC) for Staphylococcus aureus only after 16 days of vancomycin drops. Two of 3 rabbits still developed infection despite bacterial inoculation after 16 days of

Prophylactic Vancomycin Drops Reduce the Severity of Early Bacterial Keratitis in Keratoprosthesis.

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Aris Konstantopoulos

Full Text Available Artificial cornea transplantation, keratoprosthesis, improves vision for patients at high risk of failure with human cadaveric cornea. However, post-operative infection can cause visual loss and implant extrusion in 3.2-17% of eyes. Long-term vancomycin drops are recommended following keratoprosthesis to prevent bacterial keratitis. Evidence, though, in support of this practice is poor. We investigated whether prophylactic vancomycin drops prevented bacterial keratitis in an animal keratoprosthesis model.Twenty-three rabbits were assigned either to a prophylactic group (n = 13 that received vancomycin 1.4% drops 5 times/day from keratoprosthesis implantation to sacrifice, or a non-prophylactic group (n = 10 that received no drops. All rabbits had Staphylococcus aureus inoculation into the cornea at 7-12 days post-implantation and were sacrificed at predetermined time-points. Prophylactic and non-prophylactic groups were compared with slit-lamp photography (SLP, anterior segment optical coherence tomography (AS-OCT, and histology, immunohistochemistry and bacterial quantification of excised corneas. Corneal vancomycin pharmacokinetics were studied in 8 additional rabbits.On day 1 post-inoculation, the median SLP score and mean±SEM AS-OCT corneal thickness (CT were greater in the non-prophylactic than the prophylactic group (11 vs. 1, p = 0.049 and 486.9±61.2 vs. 327.4±37.1 μm, p = 0.029 respectively. On days 2 and 4, SLP scores and CT were not significantly different. Immunohistochemistry showed a greater CD11b+ve/non-CD11b+ve cell ratio in the non-prophylactic group (1.45 vs. 0.71 on day 2. Bacterial counts were not significantly different between the two groups. Corneal vancomycin concentration (2.835±0.383 μg/ml exceeded minimum inhibitory concentration (MIC for Staphylococcus aureus only after 16 days of vancomycin drops. Two of 3 rabbits still developed infection despite bacterial inoculation after 16 days of prophylactic drops

The determinants of the antibiotic resistance process.

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Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I

2009-01-01

The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. We conducted a MedLine search using the key words "determinants", "antibiotic", and "antibiotic resistance" to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.

Comparison of M.I.C.E. and Etest with CLSI agar dilution for antimicrobial susceptibility testing against oxacillin-resistant Staphylococcus spp.

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Eloiza H Campana

Full Text Available OBJECTIVE: The main objective of this study was to comparatively evaluate the performance of M.I.C.E. and Etest methodologies to that of agar dilution for determining the antimicrobial susceptibility profile of oxacillin-resistant Staphylococcus spp. METHODS: A total of 100 oxacillin-resistant Staphylococcus spp. isolates were collected from hospitalized patients at a teaching hospital. Antimicrobial susceptibility testing for vancomycin, teicoplanin and linezolid was performed using the reference CLSI agar dilution method (2009, Etest and M.I.C.E. methodologies. The MIC values were interpreted according to CLSI susceptibility breakpoints and compared by regression analysis. RESULTS: In general, the essential agreement (±1-log2 between M.I.C.E. and CLSI agar dilution was 93.0%, 84.0% and 77.0% for linezolid, teicoplanin and vancomycin, respectively. Essential agreement rates between M.I.C.E. and Etest were excellent (>90.0% for all antibiotics tested. Both strips (M.I.C.E. and Etest yielded two very major errors for linezolid. Unacceptable minor rates were observed for teicoplanin against CoNS and for vancomycin against S. aureus. CONCLUSIONS: According to our results, linezolid and teicoplanin MICs against all staphylococci and S. aureus, respectively, were more accurately predicted by M.I.C.E. strips. However, the Etest showed better performance than M.I.C.E. for predicting vancomycin MICs against all staphylococci. Thus, microbiologists must be aware of the different performance of commercially available gradient strips against staphylococci.

Vancomycin-resistant enterococci with vanA gene in treated municipal wastewater and their association with human hospital strains.

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Oravcova, Veronika; Mihalcin, Matus; Zakova, Jana; Pospisilova, Lucie; Masarikova, Martina; Literak, Ivan

2017-12-31

Vancomycin-resistant enterococci (VRE) are pathogens of increasing medical importance. In Brno, Czech Republic, we collected 37 samples from the effluent of a wastewater treatment plant (WWTP), 21 surface swabs from hospital settings, and 59 fecal samples from hospitalized patients and staff. Moreover, we collected 284 gull cloacal swabs from the colony situated 35km downstream the WWTP. Samples were cultured selectively. Enterococci were identified using MALDI-TOF MS, phenotypically tested for susceptibility to antibiotics, and by PCR for occurrence of resistance and virulence genes. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used to examine genotypic diversity. VRE carrying the vanA gene were found in 32 (86%, n=37) wastewater samples, from which we obtained 49 isolates: Enterococcus faecium (44) and Enterococcus gallinarum (2), Enterococcus casseliflavus (2), and Enterococcus raffinosus (1). From 33 (69%) of 48 inpatient stool samples, we obtained 39 vanA-carrying VRE, which belonged to E. faecium (33 isolates), Enterococcus faecalis (4), and Enterococcus raffinosus (2). Nearly one-third of the samples from hospital surfaces contained VRE with the vanA gene. VRE were not detected among gulls. Sixty-seven (84%, n=80) E. faecium isolates carried virulence genes hyl and/or esp. Virulence of E. faecalis was encoded by gelE, asa1, and cylA genes. A majority of the E. faecium isolates belonged to the clinically important sequence types ST17 (WWTP: 10 isolates; hospital: 4 isolates), ST18 (9;8), and ST78 (5;0). The remaining isolates belonged to ST555 (2;0), ST262 (1;6), ST273 (3;0), ST275 (1;0), ST549 (2;0), ST19 (0;1), ST323 (3;0), and ST884 (7;17). Clinically important enterococci carrying the vanA gene were almost continually detectable in the effluent of the WWTP, indicating insufficient removal of VRE during wastewater treatment and permanent shedding of these antibiotic resistant pathogens into the environment from this

Daptomycin versus linezolid for the treatment of vancomycin-resistant enterococcal bacteraemia: implications of daptomycin dose.

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Chuang, Y-C; Lin, H-Y; Chen, P-Y; Lin, C-Y; Wang, J-T; Chang, S-C

2016-10-01

Treatment options for vancomycin-resistant enterococci (VRE) bloodstream infection are limited. Studies comparing daptomycin or linezolid in treating VRE bloodstream infection have conflicting results and suggest daptomycin underdosing. The responses to different daptomycin doses have not been studied. We conducted a multicentre prospective cohort study to compare linezolid and daptomycin (≥6 mg/kg) for the treatment of VRE bloodstream infection. The primary outcome was 14-day mortality. We used multivariate logistic regression analysis for outcome analysis and a generalized additive model for dose-dependent response estimation. Two hundred twelve patients were included (daptomycin, n = 141; linezolid, n = 71). All-cause 14-day mortality was higher in the daptomycin group (36.9% vs. 21.1%; p 0.03). After adjusting for confounders in logistic regression, mortality was lower in the linezolid group (adjusted odds ratio (aOR), 0.45; 95% confidence interval (CI), 0.21-0.96; p 0.04). The generalized additive model showed that higher-dose daptomycin (≥9 mg/kg) was associated with better survival than lower-dose daptomycin (6-9 mg/kg). Logistic regression showed that linezolid (aOR, 0.36; 95% CI, 0.17-0.79; p 0.01) and higher-dose daptomycin (aOR, 0.26; 95% CI, 0.09-0.74; p 0.01) independently predicted lower mortality compared to lower-dose daptomycin. Linezolid was not superior to higher-dose daptomycin in terms of mortality (aOR, 1.40; 95% CI, 0.45-4.37; p 0.57). Higher-dose daptomycin had lower mortality than lower-dose daptomycin. Despite higher mortality for lower-dose daptomycin than linezolid, linezolid conferred no survival benefit compared to higher-dose daptomycin. Our findings suggest that the recommended daptomycin dose is suboptimal for treating VRE bacteraemia. Copyright © 2016. Published by Elsevier Ltd.

Intravenous Vancomycin Associated With the Development of Nephrotoxicity in Patients With Class III Obesity.

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Choi, Yookyung Christy; Saw, Stephen; Soliman, Daniel; Bingham, Angela L; Pontiggia, Laura; Hunter, Krystal; Chuang, Linda; Siemianowski, Laura A; Ereshefsky, Benjamin; Hollands, James M

2017-11-01

A consensus statement recommends initial intravenous (IV) vancomycin dosing of 15-20 mg/kg every 8- 24 hours, with an optional 25- to 30-mg/kg loading dose. Although some studies have shown an association between weight and the development of vancomycin-associated nephrotoxicity, results have been inconsistent. To evaluate the correlation between incidence of nephrotoxicity associated with weight-based IV vancomycin dosing strategies in nonobese and obese patients. This retrospective cohort study evaluated hospitalized adult patients admitted who received IV vancomycin. Patients were stratified into nonobese (body mass index [BMI] obesity class I and II (BMI 30-39.9kg/m 2 ), and obesity class III (BMI≥40 kg/m 2 ) groups; patients who were overweight but not obese were excluded. Incidence of nephrotoxicity and serum vancomycin trough concentrations were evaluated. Of a total of 62 documented cases of nephrotoxicity (15.1%), 13 (8.7%), 23 (14.3%), and 26 (26.3%) cases were observed in nonobese, obesity class I and II, and obesity class III groups, respectively ( P=0.002). Longer durations of therapy ( P20 mg/L ( Pobesity were 3-times as likely to develop nephrotoxicity when compared with nonobese patients (odds ratio [OR]=2.99; CI=1.12-7.94) and obesity class I and II patients (OR=3.14; CI=1.27-7.75). Obesity and other factors are associated with a higher risk of vancomycin-associated nephrotoxicity.

Repurposing Clinical Molecule Ebselen to Combat Drug Resistant Pathogens.

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Thangamani, Shankar; Younis, Waleed; Seleem, Mohamed N

2015-01-01

Without a doubt, our current antimicrobials are losing the battle in the fight against newly-emerged multidrug-resistant pathogens. There is a pressing, unmet need for novel antimicrobials and novel approaches to develop them; however, it is becoming increasingly difficult and costly to develop new antimicrobials. One strategy to reduce the time and cost associated with antimicrobial innovation is drug repurposing, which is to find new applications outside the scope of the original medical indication of the drug. Ebselen, an organoselenium clinical molecule, possesses potent antimicrobial activity against clinical multidrug-resistant Gram-positive pathogens, including Staphylococcus, Streptococcus, and Enterococcus, but not against Gram-negative pathogens. Moreover, the activity of ebselen against Gram-positive pathogens exceeded those activities determined for vancomycin and linezolid, drugs of choice for treatment of Enterococcus and Staphylococcus infections. The minimum inhibitory concentrations of ebselen at which 90% of clinical isolates of Enterococcus and Staphylococcus were inhibited (MIC90) were found to be 0.5 and 0.25 mg/L, respectively. Ebselen showed significant clearance of intracellular methicillin-resistant S. aureus (MRSA) in comparison to vancomycin and linezolid. We demonstrated that ebselen inhibits the bacterial translation process without affecting mitochondrial biogenesis. Additionally, ebselen was found to exhibit excellent activity in vivo in a Caenorhabditis elegans MRSA-infected whole animal model. Finally, ebselen showed synergistic activities with conventional antimicrobials against MRSA. Taken together, our results demonstrate that ebselen, with its potent antimicrobial activity and safety profiles, can be potentially used to treat multidrug resistant Gram-positive bacterial infections alone or in combination with other antibiotics and should be further clinically evaluated.

Clostridium difficile Infections: A Global Overview of Drug Sensitivity and Resistance Mechanisms

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Saeed S. Banawas

2018-01-01

Full Text Available Clostridium difficile (C. difficile is the most prevalent causative pathogen of healthcare-associated diarrhea. Notably, over the past 10 years, the number of Clostridium difficile outbreaks has increased with the rate of morbidity and mortality. The occurrence and spread of C. difficile strains that are resistant to multiple antimicrobial drugs complicate prevention as well as potential treatment options. Most C. difficile isolates are still susceptible to metronidazole and vancomycin. Incidences of C. difficile resistance to other antimicrobial drugs have also been reported. Most of the antibiotics correlated with C. difficile infection (CDI, such as ampicillin, amoxicillin, cephalosporins, clindamycin, and fluoroquinolones, continue to be associated with the highest risk for CDI. Still, the detailed mechanism of resistance to metronidazole or vancomycin is not clear. Alternation in the target sites of the antibiotics is the main mechanism of erythromycin, fluoroquinolone, and rifamycin resistance in C. difficile. In this review, different antimicrobial agents are discussed and C. difficile resistance patterns and their mechanism of survival are summarized.

Influence of an independent quarterly audit on publicly reported vancomycin-resistant enterocococi bacteremia data in Ontario, Canada.

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Prematunge, Chatura; Policarpio, Michelle E; Johnstone, Jennie; Adomako, Kwaku; Nadolny, Emily; Lam, Freda; Li, Ye; Brown, Kevin A; Garber, Gary

2018-04-13

All Ontario hospitals are mandated to self-report vancomycin-resistant enterocococi (VRE) bacteremias to Ontario's Ministry of Health and Long-term Care for public reporting purposes. Independent quarterly audits of publicly reported VRE bacteremias between September 2013 and June 2015 were carried out by Public Health Ontario. VRE bacteremia case-reporting errors between January 2009 and August 2013 were identified by a single retrospective audit. Employing a quasiexperimental pre-post study design, the relative risk of VRE bacteremia reporting errors before and after quarterly audits were modeled using Poisson regression adjusting for hospital type, case counts reported to the Ministry of Health and Long-term Care, and autocorrelation via generalized estimating equation. Overall, 24.5% (126 out of 514) of VRE bacteremias were reported in error; 114 out of 367 (31%) VRE bacteremias reported before quarterly audits and 12 out of 147 (8.1%) reported after audits were found to be incorrect. In adjusted analysis, quarterly audits of VRE bacteremias were associated with significant reductions in reporting errors when compared with before quarterly auditing (relative risk, 0.17; 95% confidence interval, 0.05-0.63). Risk of reporting errors among community hospitals were greater than acute teaching hospitals of the region (relative risk, 4.39; 95% CI, 3.07-5.70). This study found independent quarterly audits of publicly reported VRE bacteremias to be associated with significant reductions in reporting errors. Public reporting systems should consider adopting routine data audits and hospital-targeted training to improve data accuracy. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

The fosfomycin resistance gene fosB3 is located on a transferable, extrachromosomal circular intermediate in clinical Enterococcus faecium isolates.

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Xiaogang Xu

Full Text Available Some VanM-type vancomycin-resistant Enterococcus faecium isolates from China are also resistant to fosfomycin. To investigate the mechanism of fosfomycin resistance in these clinical isolates, antimicrobial susceptibility testing, filter-mating, Illumina/Solexa sequencing, inverse PCR and fosfomycin resistance gene cloning were performed. Three E. faecium clinical isolates were highly resistant to fosfomycin and vancomycin with minimal inhibitory concentrations (MICs >1024 µg/ml and >256 µg/ml, respectively. The fosfomycin and vancomycin resistance of these strains could be co-transferred by conjugation. They carried a fosfomycin resistance gene fosB encoding a protein differing by one or two amino acids from FosB, which is encoded on staphylococcal plasmids. Accordingly, the gene was designated fosB3. The fosB3 gene was cloned into pMD19-T, and transformed into E. coli DH5α. The fosfomycin MIC for transformants with fosB3 was 750-fold higher than transformants without fosB3. The fosB3 gene could be transferred by an extrachromosomal circular intermediate. The results indicate that the fosB3 gene is transferable, can mediate high level fosfomycin resistance in both Gram-positive and Gram-negative bacteria, and can be located on a circular intermediate.

Active surveillance for asymptomatic colonisation by multidrug-resistant bacteria in patients transferred to a tertiary care hospital in the occupied Palestinian territory.

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Taha, Adham Abu; Daoud, Ayman; Zaid, Sawsan; Sammour, Sajida; Belleh, Maram; Daifi, Refqa

2018-02-21

Active surveillance is important in infection control programmes, allowing the detection of patients colonised with multi-drug resistant organisms and preventing the spread of multi-drug resistant organisms. The aim of this study was to determine the rate of asymptomatic colonisation with multi-drug resistant organisms and the prevalence of each organism in patients transferred to An-Najah National University Hospital, Nablus, occupied Palestinian territory. Patients transferred from other hospitals between January and December, 2015, were screened at time of admission by taking nasal, groin, and axillary swabs. Swabs were cultured and assessed for the presence of multi-drug resistant organisms (extended spectrum β-lactamase producers, Pseudomonas aeroginosae, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococcus, and carbapenem-resistant enterobacteriaceae. Of the 822 screened patients, 265 (32%) had infections with multi-drug resistant organisms. 394 isolates of multi-drug resistant organisms were obtained: 131 (33%) isolates were extended spectrum β-lactamase producers, 119 (30%) isolates were P aeroginosae, 26 (9%) isolates were A baumannii, 94 (24%) isolates were methicillin-resistant S aureus, 13 (3%) isolates were vancomycin-resistant enterococci, and one (<1%) isolate was carbapenem-resistant enterobacteriaceae. We identified a high prevalence of asymptomatic colonisation with multidrug-resistant bacteria in transferred patients. These findings emphasise the need for a national strategy to combat the spread of multi-drug resistant organisms in the occupied Palestinian territory. An-Najah National University. Copyright © 2018 Elsevier Ltd. All rights reserved.

Polyelectrolyte complex of vancomycin as a nanoantibiotic: Preparation, in vitro and in silico studies

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Sikwal, Dhiraj R.; Kalhapure, Rahul S.; Rambharose, Sanjeev; Vepuri, Suresh; Soliman, Mahmoud; Mocktar, Chunderika; Govender, Thirumala, E-mail: govenderth@ukzn.ac.za

2016-06-01

Delivery of antibiotics by various nanosized carriers is proving to be a promising strategy to combat limitations associated with conventional dosage forms and the ever-increasing drug resistance problem. This method entails improving the pharmacokinetic parameters for accumulation at the target infection site and reducing their adverse effects. It has been proposed that antibiotic nanoparticles themselves are more effective delivery system than encapsulating the antibiotic in a nanosystem. In this study, we report on nanoparticles of vancomycin (VCM) by self-assembled amphiphilic–polyelectrolyte complexation between VCM hydrochloride and polyacrylic acid sodium (PAA). The size, polydispersity index and zeta potential of the developed nanoplexes were 229.7 ± 47.76 nm, 0.442 ± 0.075, − 30.4 ± 5.3 mV respectively, whereas complexation efficiency, drug loading and percentage yield were 75.22 ± 1.02%, 58.40 ± 1.03% and 60.60 ± 2.62% respectively. An in vitro cytotoxicity study on three mammalian cell lines using MTT assays confirmed the biosafety of the newly formulated nanoplexes. Morphological investigations using scanning electron microscope showed cube shaped hexagonal-like particles. In vitro drug release studies revealed that the drug was completely released from the nanoplexes within 12 h. In silico studies revealed that the nano-aggregation was facilitated by means of self-association of VCM in the presence of the polymer. The supramolecular pattern of the drug self-association was found to be similar to that of the VCM dimer observed in the crystal structure of the VCM available in Protein Data Bank. In vitro antibacterial activity against susceptible and resistant Staphylococcus aureus proved that the potency of VCM was retained after being formulated as the nanoplex. In conclusion, VCM nanoplexes could be a promising nanodrug delivery system to treat infections of S. aureus origin. - Highlights: • Self-assembly of vancomycin to form cube

Polyelectrolyte complex of vancomycin as a nanoantibiotic: Preparation, in vitro and in silico studies

International Nuclear Information System (INIS)

Sikwal, Dhiraj R.; Kalhapure, Rahul S.; Rambharose, Sanjeev; Vepuri, Suresh; Soliman, Mahmoud; Mocktar, Chunderika; Govender, Thirumala

2016-01-01

Delivery of antibiotics by various nanosized carriers is proving to be a promising strategy to combat limitations associated with conventional dosage forms and the ever-increasing drug resistance problem. This method entails improving the pharmacokinetic parameters for accumulation at the target infection site and reducing their adverse effects. It has been proposed that antibiotic nanoparticles themselves are more effective delivery system than encapsulating the antibiotic in a nanosystem. In this study, we report on nanoparticles of vancomycin (VCM) by self-assembled amphiphilic–polyelectrolyte complexation between VCM hydrochloride and polyacrylic acid sodium (PAA). The size, polydispersity index and zeta potential of the developed nanoplexes were 229.7 ± 47.76 nm, 0.442 ± 0.075, − 30.4 ± 5.3 mV respectively, whereas complexation efficiency, drug loading and percentage yield were 75.22 ± 1.02%, 58.40 ± 1.03% and 60.60 ± 2.62% respectively. An in vitro cytotoxicity study on three mammalian cell lines using MTT assays confirmed the biosafety of the newly formulated nanoplexes. Morphological investigations using scanning electron microscope showed cube shaped hexagonal-like particles. In vitro drug release studies revealed that the drug was completely released from the nanoplexes within 12 h. In silico studies revealed that the nano-aggregation was facilitated by means of self-association of VCM in the presence of the polymer. The supramolecular pattern of the drug self-association was found to be similar to that of the VCM dimer observed in the crystal structure of the VCM available in Protein Data Bank. In vitro antibacterial activity against susceptible and resistant Staphylococcus aureus proved that the potency of VCM was retained after being formulated as the nanoplex. In conclusion, VCM nanoplexes could be a promising nanodrug delivery system to treat infections of S. aureus origin. - Highlights: • Self-assembly of vancomycin to form cube

Prevalence of the antibiotic resistance genes in coagulase-positive- and negative-Staphylococcus in chicken meat retailed to consumers

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Kamelia Mahmoud Osman

2016-11-01

Full Text Available The use of antibiotics in farm management (growing crops and raising animals has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mecA and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA, methicillin-resistant S. aureus (MRSA, methicillin-resistant coagulase-negative staphylococci (MRCNS and methicillin-susceptible coagulase-negative staphylococci (MSCNS isolated from the retail trade of ready-to-eat raw chicken meat samples collected during one year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim and vancomycin and their endorsement of the quinolone resistance determining region, mecA and cfr genes. The isolation results revealed 50 isolates, CPS (14 and CNS (36, representing ten species (S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius and S. lentus. Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mecA gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides and streptogramin B (MLS(B in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining

Prevalence of the Antibiotic Resistance Genes in Coagulase-Positive-and Negative-Staphylococcus in Chicken Meat Retailed to Consumers.

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Osman, Kamelia; Badr, Jihan; Al-Maary, Khalid S; Moussa, Ihab M I; Hessain, Ashgan M; Girah, Zeinab M S Amin; Abo-Shama, Usama H; Orabi, Ahmed; Saad, Aalaa

2016-01-01

The use of antibiotics in farm management (growing crops and raising animals) has become a major area of concern. Its implications is the consequent emergence of antibiotic resistant bacteria (ARB) and accordingly their access into the human food chain with passage of antibiotic resistance genes (ARG) to the normal human intestinal microbiota and hence to other pathogenic bacteria causative human disease. Therefore, we pursued in this study to unravel the frequency and the quinolone resistance determining region, mec A and cfr genes of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-resistant coagulase-negative staphylococci (MRCNS) and methicillin-susceptible coagulase-negative staphylococci (MSCNS) isolated from the retail trade of ready-to-eat raw chicken meat samples collected during 1 year and sold across the Great Cairo area. The 50 Staphylococcus isolated from retail raw chicken meat were analyzed for their antibiotic resistance phenotypic profile on 12 antibiotics (penicillin, oxacillin, methicillin, ampicillin-sulbactam, erythromycin, tetracycline, clindamycin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole-trimethoprim, and vancomycin) and their endorsement of the quinolone resistance determining region, mec A and cfr genes. The isolation results revealed 50 isolates, CPS (14) and CNS (36), representing ten species ( S. aureus, S. hyicus, S. epidermedius, S. lugdunensis, S. haemolyticus, S. hominus, S. schleiferi, S. cohnii, S. intermedius , and S. lentus ). Twenty seven isolates were methicillin-resistant. Out of the characterized 50 staphylococcal isolates, three were MRSA but only 2/3 carried the mec A gene. The ARG that bestows resistance to quinolones, β-lactams, macrolides, lincosamides, and streptogramin B [MLS( B )] in MRSA and MR-CNS were perceived. According to the available literature, the present investigation was a unique endeavor into the identification of the quinolone-resistance-determining

Lavage with allicin in combination with vancomycin inhibits biofilm formation by Staphylococcus epidermidis in a rabbit model of prosthetic joint infection.

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Haohan Zhai

Full Text Available BACKGROUND AND AIM: The present anti-infection strategy for prosthetic joint infections (PJI includes the use of antibiotics and surgical treatments, but the bacterial eradication rates are still low. One of the major challenges is the formation of biofilm causing poor bacterial eradication. Recently it has been reported that allicin (diallyl thiosulphinate, an antibacterial principle of garlic, can inhibit bacteria adherence and prevent biofilm formation in vitro. However, whether allicin could inhibit biofilm formation in vivo is unknown. The aim of this study was to investigate the effects of allicin on biofilm formation, and whether allicin could potentiate the bactericidal effect of vancomycin in a rabbit PJI model. METHODS: A sterile stainless-steel screw with a sterile ultra-high molecular weight polyethylene washer was inserted into the lateral femoral condyle of the right hind knee joint of rabbit, and 1 mL inoculum containing 104 colony-forming units of Staphylococcus epidermidis was inoculated into the knee joint (n = 32. Fourteen days later, rabbits randomly received one of the following 4 treatments using continuous lavages: normal saline, vancomycin (20 mcg/mL, allicin (4 mg/L, or allicin (4 mg/L plus vancomycin (20 mcg/mL. Three days later, the washer surface biofilm formation was examined by scanning electron microscopy (SEM. The bacterial counts within the biofilm of implanted screws were determined by bacterial culture. RESULTS: The lowest number of viable bacterial counts of Staphylococcus epidermidis recovered from the biofilm was in the rabbits treated with allicin plus vancomycin (P<0.01 vs. all other groups. The biofilm formation was significantly reduced or undetectable by SEM in rabbits receiving allicin or allicin plus vancomycin. CONCLUSION: Intra-articular allicincan inhibit biofilm formation and enhance the bactericidal effect of vancomycin on implant surface in vivo. Allicin in combination with vancomycin may be

Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil.

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Pereira, M S; Siqueira-Júnior, J P

1995-06-01

Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.

The determinants of the antibiotic resistance process

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Beatriz Espinosa Franco

2009-04-01

Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community.Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem.Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded.Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance.Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.Keywords: antibiotic drug resistance

An Investigation of Antibiotic Resistance Pattern in the Strains of Methicillin-resistant Staphylococcus epidermidis Isolated From Clinical Samples in Isfahan Province, Iran

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Fahimeh Nourbakhsh

2016-08-01

Full Text Available Background and Objectives: Staphylococcus epidermidis is one of the effective factors causing nosocomial infections. This study was performed to investigate the antibiotic resistance pattern in the methicillin-resistant S. epidermidis strains isolated from clinical samples in Isfahan Province. Methods: In this descriptive cross-sectional study, 150 isolates of S. epidermidis were isolated from detected from the patients hospitalized in hospitals and treatment centers of Isfahan City. The antibiotic resistance pattern was evaluated by disk diffusion method. The presence of the gene encoding antibiotic resistance to methicillin (mec A in the isolates were investigated using PCR method. Data were analyzed with Chi-square and Fisher's exact statistical tests. Results: In this study, most isolates were related to urinary tract infections. The highest resistance was reported to penicillin (98.9%, erythromycin (89.4%, ciprofloxacin (77.7%, clindamycin (65.9%, tetracycline (63.2%, and meticillin (54%. None of the strains showed resistance to vancomycin and linezolid. Molecular studies indicated the presence of mecA gene in 76% of the studied isolates. Conclusion: According to the results of this study, vancomycin and linezolid antibiotics can be the best choice of treatment for infections caused by S. epidermidis. Also, high resistance of S. epidermidis can be a serious warning for increased multiple antibiotic resistance. Molecular studies are indicative of high sensitivity of molecular methods in the investigation of methicillin-resistant isolates.  

Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe

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Wegener, Henrik Caspar; Aarestrup, Frank Møller; Jensen, Lars Bogø

1999-01-01

on the Tn1546 transposon. Furthermore, glycopeptide-resistant strains, as well as resistance determinants, can be transmitted from animals to humans. Two antimicrobial classes expected to provide the future therapeutic options for treatment of infections with vancomycin-resistant enterococci have analogues......Supplementing animal feed with antimicrobial agents to enhance growth has been common practice for more than 30 years and is estimated to constitute more than half the total antimicrobial use worldwide. The potential public health consequences of this use have been debated; however, until recently......, clear evidence of a health risk was not available. Accumulating evidence now indicates that the use of the glycopeptide avoparcin as a growth promoter has created in food animals a major reservoir of Enterococcus faecium, which contains the high level glycopeptide resistance determinant vanA, located...

Resistance of Staphylococcus aureus to antimicrobial agents in Ethiopia: a meta-analysis

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Serawit Deyno

2017-08-01

Full Text Available Abstract Background Emergence of antimicrobial resistance by Staphylococcus aureus has limited treatment options against its infections. The purpose of this study was to determine the pooled prevalence of resistance to different antimicrobial agents by S. aureus in Ethiopia. Methods Web-based search was conducted in the databases of PubMed, Google Scholar, Hinari, Scopus and the Directory of Open Access Journals (DOAJ to identify potentially eligible published studies. Required data were extracted and entered into Excel spread sheet. Statistical analyses were performed using Stata version 13.0. The metaprop Stata command was used to pool prevalence values. Twenty-one separate meta-analysis were done to estimate the pooled prevalence of the resistance of S. aureus to twenty-one different antimicrobial agents. Heterogeneity among the studies was assessed using the I2 statistic and chi-square test. Publication bias was assessed using Egger’s test. Because of significant heterogeneity amongst the studies, the random effects model was used to pool prevalence values. Results The electronic database search yielded 1317 studies among which 45 studies met our inclusion criteria. Our analyses demonstrated very high level of resistance to amoxicillin (77% [95% confidence interval (CI: 68%, 0.85%], penicillin (76% [95% CI: 67%, 84%], ampicillin (75% [95% CI: 65%, 85%], tetracycline (62% [95% CI: 55%, 68%], methicillin (47% [95% CI: 33%, 61%], cotrimoxaziole (47% [95% CI: 40%, 55%], doxycycline (43% [95% CI: 26%, 60%], and erythromycin (41% [95% CI: 29%, 54%]. Relatively low prevalence of resistance was observed with kanamycin (14% [95% CI: 5%, 25%] and ciprofloxacin (19% [95% CI: 13%, 26%]. The resistance level to vancomycin is 11% 995% CI: (4%, 20%. High heterogeneity was observed for each of the meta-analysis performed (I2 ranging from 79.36% to 95.93%; all p-values ≤0.01. Eggers’ test did not show a significant publication bias for all

Peak Measurement for Vancomycin AUC Estimation in Obese Adults Improves Precision and Lowers Bias.

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Pai, Manjunath P; Hong, Joseph; Krop, Lynne

2017-04-01

Vancomycin area under the curve (AUC) estimates may be skewed in obese adults due to weight-dependent pharmacokinetic parameters. We demonstrate that peak and trough measurements reduce bias and improve the precision of vancomycin AUC estimates in obese adults ( n = 75) and validate this in an independent cohort ( n = 31). The precision and mean percent bias of Bayesian vancomycin AUC estimates are comparable between covariate-dependent ( R 2 = 0.774, 3.55%) and covariate-independent ( R 2 = 0.804, 3.28%) models when peaks and troughs are measured but not when measurements are restricted to troughs only ( R 2 = 0.557, 15.5%). Copyright © 2017 American Society for Microbiology.

In Vitro Synergy of Telavancin and Rifampin Against Enterococcus faecium Resistant to Both Linezolid and Vancomycin.

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Pankey, George A; Ashcraft, Deborah S

2013-01-01

An emerging pathogen is Enterococcus faecium resistant to both linezolid and vancomycin (LRVRE). Antimicrobial combinations may be required for therapy and need to be evaluated. The combination of daptomycin and rifampin has demonstrated good in vitro activity against gram-positive bacteria, including E faecium. Telavancin, a newer lipoglycopeptide, has shown in vitro activity against E faecium. We evaluated the combination of telavancin and rifampin and compared the results to the combination of daptomycin and rifampin used previously on the same isolates. Twenty-four genetically unique (by pulsed-field gel electrophoresis), clinical LRVRE isolates were collected in the United States from 2001-2004. Etest minimal inhibitory concentrations (MICs) (μg/mL) were 0.064-8 for telavancin, 1-4 for daptomycin, and 0.012 to >32 for rifampin. In vitro synergy testing was performed in triplicate by an Etest MIC:MIC ratio method, and summation fractional inhibitory concentration (ΣFIC) was calculated: synergy ≤0.5; indifference >0.5-4; and antagonism >4. The Etest method showed synergy (ΣFICs of 0.1-0.5) with telavancin + rifampin in 20/24 (83%) isolates and indifference (ΣFICs of 0.6-0.8) in 4/24 (17%) isolates. Similarly, the daptomycin + rifampin combination showed synergy (ΣFICs of 0.1-0.5) in 21/24 (88%) isolates and indifference (ΣFICs of 0.6-1.0) in 3/24 (12%) isolates by the Etest method. No antagonism was found. In vitro synergy with both combinations (rifampin + telavancin or daptomycin) was 83% and 88%, respectively, by Etest against these LRVRE isolates. Although both daptomycin and telavancin in combination with rifampin showed a high incidence of synergistic activity, further in vitro synergy testing with this combination should be performed against additional E faecium isolates. In vitro synergy may or may not translate into in vivo effectiveness.

Molecular Characterization of Methicillin Resistant Staphylococcus aureus Strains Isolated from Intensive Care Units in Iran: ST22-SCCmec IV/t790 Emerges as the Major Clone.

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Goudarzi, Mehdi; Goudarzi, Hossein; Sá Figueiredo, Agnes Marie; Udo, Edet E; Fazeli, Maryam; Asadzadeh, Mohammad; Seyedjavadi, Sima Sadat

2016-01-01

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) in different patient populations is a major public health concern. This study determined the prevalence and distribution of circulating molecular types of MRSA in hospitalized patients in ICU of hospitals in Tehran. A total of 70 MRSA isolates were collected from patients in eight hospitals. Antimicrobial resistance patterns were determined using the disk diffusion method. The presence of toxin encoding genes and the vancomycin resistance gene were determined by PCR. The MRSA isolates were further analyzed using multi-locus sequence, spa, SCCmec, and agr typing. The MRSA prevalence was 93.3%. Antimicrobial susceptibility testing revealed a high resistance rate (97.1%) to ampicillin and penicillin. The rate of resistance to the majority of antibiotics tested was 30% to 71.4%. Two isolates belonging to the ST22-SCCmec IV/t790 clone (MIC ≥ 8 μg/ml) had intermediate resistance to vancomycin. The majority of MRSA isolates (24.3%) were associated with the ST22-SCCmec IV/t790 clone; the other MRSA clones were ST859-SCCmec IV/t969 (18.6%), ST239-SCCmec III/t037 (17.1%), and ST291-SCCmec IV/t030 (8.6%). The circulating MRSA strains in Iranian hospitals were genetically diverse with a relatively high prevalence of the ST22-SCCmec IV/t790 clone. These findings support the need for future surveillance studies on MRSA to better elucidate the distribution of existing MRSA clones and detect emergence of new MRSA clones.

Bacillus coagulans GBI-30, 6086 limits the recurrence of Clostridium difficile-Induced colitis following vancomycin withdrawal in mice

Science.gov (United States)

2012-01-01

Background Recently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC30) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 10463 was given by oro-gastric gavage at ≈ 5x104 CFU to induce colitis. Mice were treated on study days 6 to 10 with vancomycin (50 mg/kg) (vanco) or vehicle (saline) by gavage. On days 10 to16, mice were dosed by gavage with saline vehicle or BC30 (2 x 109 CFU per day). Mice were monitored for mortality, weight loss and diarrhea. On study days 14, 16 and 17, stools and colons were collected for analyzing other parameters of colitis. Results The mean stool consistency score in Vehicle/C.difficile/Vanco mice increased from 0.4 (day 10) to a range of 1.1 to 1.4 (days 14 to 17), indicating the recurrence of colitis. On days 13 through 17, the stool consistency scores for the vancomycin/BC30 mice were significantly lower (p< 0.05) than for the vancomycin/vehicle cohort of animals. On day 17, 88.9% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0004). Colonic myeloperoxidase (Units/2 cm colon) was significantly (p < 0.05) reduced from 4.3 ± 0.7 (Vehicle/C.difficile/Vanco) to 2.6 ± 0.2 (BC30/C. Difficle/Vanco). The colonic histology score and Keratinocyte derived-chemokine level in the colon were also lower in BC30 treated mice. Summary In BC30-treated mice, there was evidence of better stool consistency, as well as improved biochemical and histological indices of colitis, following initial treatment of animals with vancomycin. Conclusion BC30 limited the recurrence of CD-induced colitis following vancomycin withdrawal in mice. PMID

Bacillus coagulans GBI-30, 6086 limits the recurrence of Clostridium difficile-Induced colitis following vancomycin withdrawal in mice.

Science.gov (United States)

Fitzpatrick, Leo R; Small, Jeffrey S; Greene, Wallace H; Karpa, Kelly D; Farmer, Sean; Keller, David

2012-10-22

Recently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC30) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 10463 was given by oro-gastric gavage at ≈ 5x104 CFU to induce colitis. Mice were treated on study days 6 to 10 with vancomycin (50 mg/kg) (vanco) or vehicle (saline) by gavage. On days 10 to16, mice were dosed by gavage with saline vehicle or BC30 (2 x 109 CFU per day). Mice were monitored for mortality, weight loss and diarrhea. On study days 14, 16 and 17, stools and colons were collected for analyzing other parameters of colitis. The mean stool consistency score in Vehicle/C.difficile/Vanco mice increased from 0.4 (day 10) to a range of 1.1 to 1.4 (days 14 to 17), indicating the recurrence of colitis. On days 13 through 17, the stool consistency scores for the vancomycin/BC30 mice were significantly lower (p< 0.05) than for the vancomycin/vehicle cohort of animals. On day 17, 88.9% of mice treated with BC30 had normal stools, while this value was 0% with vehicle treatment (p value = 0.0004). Colonic myeloperoxidase (Units/2 cm colon) was significantly (p < 0.05) reduced from 4.3 ± 0.7 (Vehicle/C.difficile/Vanco) to 2.6 ± 0.2 (BC30/C. Difficle/Vanco). The colonic histology score and Keratinocyte derived-chemokine level in the colon were also lower in BC30 treated mice. In BC30-treated mice, there was evidence of better stool consistency, as well as improved biochemical and histological indices of colitis, following initial treatment of animals with vancomycin. BC30 limited the recurrence of CD-induced colitis following vancomycin withdrawal in mice.

The Role of Vancomycin on Meningitis

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Ahmed I. Shatat and P.I.C.U team

2014-06-01

Conclusion: After the previous discussion of the results obtained from this study, the researchers concluded that most of the cases diagnosed meningitis was aseptic and there was no need for antibiotics. Also in those who diagnosed as bacterial vancomycin was not essential in all cases, this confirmed by the absence of any differences in the outcome. [Cukurova Med J 2014; 39(3.000: 501-511

Repurposing Clinical Molecule Ebselen to Combat Drug Resistant Pathogens.

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Shankar Thangamani

Full Text Available Without a doubt, our current antimicrobials are losing the battle in the fight against newly-emerged multidrug-resistant pathogens. There is a pressing, unmet need for novel antimicrobials and novel approaches to develop them; however, it is becoming increasingly difficult and costly to develop new antimicrobials. One strategy to reduce the time and cost associated with antimicrobial innovation is drug repurposing, which is to find new applications outside the scope of the original medical indication of the drug. Ebselen, an organoselenium clinical molecule, possesses potent antimicrobial activity against clinical multidrug-resistant Gram-positive pathogens, including Staphylococcus, Streptococcus, and Enterococcus, but not against Gram-negative pathogens. Moreover, the activity of ebselen against Gram-positive pathogens exceeded those activities determined for vancomycin and linezolid, drugs of choice for treatment of Enterococcus and Staphylococcus infections. The minimum inhibitory concentrations of ebselen at which 90% of clinical isolates of Enterococcus and Staphylococcus were inhibited (MIC90 were found to be 0.5 and 0.25 mg/L, respectively. Ebselen showed significant clearance of intracellular methicillin-resistant S. aureus (MRSA in comparison to vancomycin and linezolid. We demonstrated that ebselen inhibits the bacterial translation process without affecting mitochondrial biogenesis. Additionally, ebselen was found to exhibit excellent activity in vivo in a Caenorhabditis elegans MRSA-infected whole animal model. Finally, ebselen showed synergistic activities with conventional antimicrobials against MRSA. Taken together, our results demonstrate that ebselen, with its potent antimicrobial activity and safety profiles, can be potentially used to treat multidrug resistant Gram-positive bacterial infections alone or in combination with other antibiotics and should be further clinically evaluated.

Vancomycin-modified Fe3O4@SiO2@Ag microflowers as effective antimicrobial agents

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Wang C

2017-04-01

Full Text Available Chongwen Wang,1,2,* Kehan Zhang,2,* Zhe Zhou,2,* Qingjun Li,2 Liting Shao,2 Rong Zhang Hao,3 Rui Xiao,2 Shengqi Wang1,2 1College of Life Sciences & Bio-Engineering, Beijing University of Technology, 2Beijing Key Laboratory of New Molecular Diagnosis Technologies for Infectious Diseases, Beijing Institute of Radiation Medicine, Beijing, 3Institute for Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Nanomaterials combined with antibiotics exhibit synergistic effects and have gained increasing interest as promising antimicrobial agents. In this study, vancomycin-modified magnetic-based silver microflowers (Van/Fe3O4@SiO2@Ag microflowers were rationally designed and prepared to achieve strong bactericidal ability, a wide antimicrobial spectrum, and good recyclability. High-performance Fe3O4@SiO2@Ag microflowers served as a multifunction-supporting matrix and exhibited sufficient magnetic response property due to their 200 nm Fe3O4 core. The microflowers also possessed a highly branched flower-like Ag shell that provided a large surface area for effective Ag ion release and bacterial contact. The modified-vancomycin layer was effectively bound to the cell wall of bacteria to increase the permeability of the cell membrane and facilitate the entry of the Ag ions into the bacterium, resulting in cell death. As such, the fabricated Van/Fe3O4@SiO2@Ag microflowers were predicted to be an effective and environment-friendly antibacterial agent. This hypothesis was verified through sterilization of Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, with minimum inhibitory concentrations of 10 and 20 µg mL-1, respectively. The microflowers also showed enhanced effect compared with bare Fe3O4@SiO2@Ag microflowers and free-form vancomycin, confirming the synergistic effects of the combination of the

Vancomycin-Rifampin Combination Therapy Has Enhanced Efficacy against an Experimental Staphylococcus aureus Prosthetic Joint Infection

Science.gov (United States)

Niska, Jared A.; Shahbazian, Jonathan H.; Ramos, Romela Irene; Francis, Kevin P.; Bernthal, Nicholas M.

2013-01-01

Treatment of prosthetic joint infections often involves a two-stage exchange, with implant removal and antibiotic spacer placement followed by systemic antibiotic therapy and delayed reimplantation. However, if antibiotic therapy can be improved, one-stage exchange or implant retention may be more feasible, thereby decreasing morbidity and preserving function. In this study, a mouse model of prosthetic joint infection was used in which Staphylococcus aureus was inoculated into a knee joint containing a surgically placed metallic implant extending from the femur. This model was used to evaluate whether combination therapy of vancomycin plus rifampin has increased efficacy compared with vancomycin alone against these infections. On postoperative day 7, vancomycin with or without rifampin was administered for 6 weeks with implant retention. In vivo bioluminescence imaging, ex vivo CFU enumeration, X-ray imaging, and histologic analysis were carried out. We found that there was a marked therapeutic benefit when vancomycin was combined with rifampin compared with vancomycin alone. Taken together, our results suggest that the mouse model used could serve as a valuable in vivo preclinical model system to evaluate and compare efficacies of antibiotics and combinatory therapy for prosthetic joint infections before more extensive studies are carried out in human subjects. PMID:23917317

Utilization Pattern of Vancomycin in a University Teaching Hospital ...

African Journals Online (AJOL)

HP

vis a vis to the Hospital Infection Control Practices Advisory Committee (HICPAC) guidelines and the ... effective against most Gram-positive bacteria ... Proper use of TDM procedures along ..... between antecedent vancomycin treatment and.

Population Pharmacokinetic Model for Vancomycin Used in Open Heart Surgery: Model-Based Evaluation of Standard Dosing Regimens.

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Alqahtani, Saeed A; Alsultan, Abdullah S; Alqattan, Hussain M; Eldemerdash, Ahmed; Albacker, Turki B

2018-04-23

The purpose of this study was to investigate the population pharmacokinetics of vancomycin in patients undergoing open heart surgery. In this observational pharmacokinetic study, multiple blood samples were drawn over a 48-h period of intravenous vancomycin in patients who were undergoing open heart surgery. Blood samples were analysed using the Architect i4000SR Immunoassay Analyzer. Population pharmacokinetic models were developed using Monolix 4.4 software. Pharmacokinetic-pharmacodynamic (PK-PD) simulations were performed to explore the ability of different dosage regimens to achieve the pharmacodynamic targets. One-hundred and sixty-eight blood samples were analysed from 28 patients. The pharmacokinetics of vancomycin was best described by a two-compartment model with between-subject variability in CL, V of the central compartment, and V of the peripheral compartment. CL and central compartment V of vancomycin were related to CL CR , body weight, and albumin concentration. Dosing simulations showed that standard dosing regimens of 1 and 1.5 g failed to achieve the PK-PD target of AUC 0--24 /MIC > 400 for an MIC of 1 mg/L, while high weight-based dosing regimens were able to achieve the PK-PD target. In summary, administration of standard doses of 1 and 1.5 g of vancomycin two times daily provided inadequate antibiotic prophylaxis in patients undergoing open heart surgery. The same findings were obtained when 15 mg/kg and 20 mg/kg doses of vancomycin were administered. Achieving the PK-PD target required higher doses (25 mg/kg and 30 mg/kg) of vancomycin. Copyright © 2018 American Society for Microbiology.

The effect of antibiotic use on prevalence of nosocomial vancomycin-resistant enterococci- an ecologic study

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Cornelius Remschmidt

2017-09-01

Full Text Available Abstract Background Vancomycin-resistant enterococci (VRE are among the most common antimicrobial-resistant pathogens causing nosocomial infections. Although antibiotic use has been identified as a risk factor for VRE, it remains unclear which antimicrobial agents particularly facilitate VRE selection. Here, we assessed whether use of specific antimicrobial agents is independently associated with healthcare-associated (HA VRE rates in a university hospital setting in Berlin, Germany. Methods We conducted the study between January 2014 and December 2015 at the Charité-university hospital of Berlin, Germany. From the hospital pharmacy, we extracted data for all antibacterials for systemic use (anatomical therapeutic chemical (ATC-classification J01 and calculated ward specific antibiotic consumption in defined daily doses (DDDs per 100 patient-days (PD. We used the microbiology laboratory database to identify all patients with isolation of invasive or non-invasive VRE and calculated HA-VRE incidence as nosocomial VRE-cases per 100 patients and HA-VRE incidence density as nosocomial VRE-cases per 1000 PD. We defined VRE isolates as hospital-acquired if they were identified three days or later after hospital admission and otherwise as community-acquired (CA-VRE. We performed univariable and multivariable regression analyses to estimate the association of the frequency of HA-VRE per month with antibiotic use and other parameters such as length of stay, type of ward or presence of at least one CA-VRE on ward. In a second analysis, we considered only patients with VRE infections. Results We included data from 204,054 patients with 948,380 PD from 61 wards. Overall, 1430 VRE-cases were identified of which 409 (28.6% were considered hospital-acquired (HA. We found that carbapenem use in the current month and prior-month use of glycopeptides increased the risk for HA-VRE by 1% per 1 DDD/100 PD and 3% per 1 DDD/100 PD, respectively. However, when only VRE

Synchrotron radiation infrared microspectroscopy to assess the activity of vancomycin against endocarditis vegetation bacteria.

Science.gov (United States)

Batard, Eric; Jamme, Frédéric; Montassier, Emmanuel; Bertrand, Dominique; Caillon, Jocelyne; Potel, Gilles; Dumas, Paul

2011-06-01

Infrared microspectroscopy was used to show that vancomycin alters infrared spectra of endocarditis vegetation bacteria, and that vancomycin effects on bacterial biochemical contents are unevenly distributed between peripheral and central areas of bacterial masses. Infrared microspectroscopy is useful to study the activity of antibacterial agents against bacteria in tissues. Copyright © 2011 Elsevier B.V. All rights reserved.

Identifying the Interaction of Vancomycin With Novel pH-Responsive Lipids as Antibacterial Biomaterials Via Accelerated Molecular Dynamics and Binding Free Energy Calculations.

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Ahmed, Shaimaa; Vepuri, Suresh B; Jadhav, Mahantesh; Kalhapure, Rahul S; Govender, Thirumala

2018-06-01

Nano-drug delivery systems have proven to be an efficient formulation tool to overcome the challenges with current antibiotics therapy and resistance. A series of pH-responsive lipid molecules were designed and synthesized for future liposomal formulation as a nano-drug delivery system for vancomycin at the infection site. The structures of these lipids differ from each other in respect of hydrocarbon tails: Lipid1, 2, 3 and 4 have stearic, oleic, linoleic, and linolenic acid hydrocarbon chains, respectively. The impact of variation in the hydrocarbon chain in the lipid structure on drug encapsulation and release profile, as well as mode of drug interaction, was investigated using molecular modeling analyses. A wide range of computational tools, including accelerated molecular dynamics, normal molecular dynamics, binding free energy calculations and principle component analysis, were applied to provide comprehensive insight into the interaction landscape between vancomycin and the designed lipid molecules. Interestingly, both MM-GBSA and MM-PBSA binding affinity calculations using normal molecular dynamics and accelerated molecular dynamics trajectories showed a very consistent trend, where the order of binding affinity towards vancomycin was lipid4 > lipid1 > lipid2 > lipid3. From both normal molecular dynamics and accelerated molecular dynamics, the interaction of lipid3 with vancomycin is demonstrated to be the weakest (∆G binding  = -2.17 and -11.57, for normal molecular dynamics and accelerated molecular dynamics, respectively) when compared to other complexes. We believe that the degree of unsaturation of the hydrocarbon chain in the lipid molecules may impact on the overall conformational behavior, interaction mode and encapsulation (wrapping) of the lipid molecules around the vancomycin molecule. This thorough computational analysis prior to the experimental investigation is a valuable approach to guide for predicting the encapsulation

Determining the specific electric resistance of rock

Energy Technology Data Exchange (ETDEWEB)

Persad' ko, V.Ia.

1982-01-01

Data are presented on perfecting the method of laboratory determination of the specific electric resistance of a rock formation. The average error in determining the specific electric resistance of the core at various locations is no more than two percent with low resistance values (2-5 ohms).

Antimicrobial resistance in gram-positive pathogens isolated in the UK between October 1996 and January 1997.

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Andrews, J; Ashby, J; Jevons, G; Lines, N; Wise, R

1999-05-01

Antimicrobial resistance in gram-positive pathogens from 30 centres in the UK (ten Teaching, ten Associate Teaching and ten District General Hospitals) was studied over a 4 month period between October 1996 and January 1997. High-level resistance (HLR) and low-level resistance (LLR) to penicillin amongst pneumococci was 3.3% and 3.4%, respectively. However, considerable variation in resistance rates was observed depending on geographical location (LLR range 0-15.4% and HLR range 0-30.8%). Considerable variation in resistance rates was also observed for Staphylococcus aureus to methicillin, with rates ranging from 0% to 56.7% depending on locality. Using conventional MIC methodology, none of the isolates of S. aureus was considered as having reduced sensitivity to vancomycin. However, eight isolates grew on Brain Heart Infusion Agar containing vancomycin (4 mg/L) after prolonged incubation and are therefore worthy of further investigation by electron microscopy. With Enterococcus faecalis, resistance rates were similar between the three types of hospital and only four isolates were considered resistant to glycopeptide antibiotics (one vanA and three vanB phenotype).

Prevalence of coagulase-negative staphylococci and determination of antimicrobial resistance in accompany with types of SCCmec in isolated of nosocomial infections

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Mohammad Reza Arabestani

2016-03-01

Full Text Available Background: Coagulase-negative staphylococci (CoNS were considered as contaminats previously, but, during the past decade considered as one of the most common photogenic bacteria in hospital. Resistance to beta-lactams especially methicillin in staphylococcus species is being worrying in hospitals. Rapid identification of mechanisms of resistance and confirmation of their resistance to methicillin is a basic principle for antibiotic treatment. The aim of this study was to determine antibiotic resistance, frequency of mecA gene, and determination of SCCmec types in CoNS isolates from teaching hospitals in Iran. Methods: The descriptive cross-sectional study was carried out one hundred clinical samples isolated from patients with an average age of 7-69 years at teaching hospitals in Hamadan City, Iran, from September 2014 to February 2015. After confirmation of isolates by microbiological standard biochemical tests, antimicrobial susceptibility testing was performed by disk agar diffusion (DAD method. After extraction of isolated genomicm, mecA gene was detected. Then, the types of SCCmec were performed by PCR. Results: In this study, 387 clinical samples were collected which among 100 CoNS isolated, Staphylococcus epidermidis was the most prevalent species with frequency 55 (55%, followed by S. haemolyticus 40(40% and S. saprophyticus 5(5%. The highest antibiotic susceptibility was to rifampin 96(96% and the lowest resistance was detected for trimethoprim/sulfamethoxazole (TMP/SMX 47(47%. None of the strains were resistant to vancomycin. Resistance to methicillin was detected in 50% of CoNS isolates. Typing of SCCmec was performed by The polymerase chain reaction (PCR. Frequency types of SCCmec was type III with frequency 13(13%, type V 11(11%, type II 6(6%, type IV 4 (4%, type I 3(3% respectively. Thirteen isolated was not typable in this study. Conclusion: The result of this study showed that a large percentage of coagulase

Antimicrobial resistance in faecal samples from buffalo, wildebeest and zebra grazing together with and without cattle in Tanzania

DEFF Research Database (Denmark)

Katakweba, A. A. S.; Møller, K. S.; Muumba, J.

2015-01-01

number of resistant Escherichia coli and Enterococci than cattle, but with no general influence in wild life of co-grazing with cattle. Vancomycin-resistant Enterococci were detected in wild life samples, and E. coli resistant to cefotaxime and enrofloxacin were observed among isolates from all wild life...

Plasmid Mediated Antibiotic and Heavy Metal Resistance in Bacillus Strains Isolated From Soils in Rize, Turkey

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Elif SEVİM

2015-09-01

Full Text Available Fifteen Bacillus strains which were isolated from soil samples were examined for resistance to 17 different antibiotics (ampicillin, methicillin, erythromycin, norfloxacin, cephalotine, gentamycin, ciprofloxacin, streptomycin, tobramycin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, vancomycin, oxacilin, neomycin, kanamycin and, novabiocin and to 10 different heavy metals (copper, lead, cobalt, chrome, iron, mercury, zinc, nickel, manganese and, cadmium and for the presence of plasmid DNA. A total of eleven strains (67% were resistant to at least one antibiotic. The most common resistance was observed against methicillin and oxacillin. The most resistance strains were found as Bacillus sp. B3 and Bacillus sp. B11. High heavy metal resistance against copper, chromium, zinc, iron and nickel was detected, but mercury and cobalt resistance was not detected, except for 3 strains (B3, B11, and B12 which showed mercury resistance. It has been determined that seven Bacillus strains have plasmids. The isolated plasmids were transformed into the Bacillus subtilis W168 and it was shown that heavy metal and antibiotic resistance determinants were carried on these plasmids. These results showed that there was a correlation between plasmid content and resistance for both antibiotic and heavy metal resistance

Detection of antibiotic resistance in probiotics of dietary supplements

KAUST Repository

Wong, Aloysius Tze

2015-09-14

Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain.

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Guerrero-Ramos, Emilia; Cordero, Jorge; Molina-González, Diana; Poeta, Patrícia; Igrejas, Gilberto; Alonso-Calleja, Carlos; Capita, Rosa

2016-02-01

A total of 55 enterococci (45 Enterococcus faecium, 7 Enterococcus faecalis, and three Enterococcus durans) isolated from the meat of wild game animals (roe deer, boar, rabbit, pheasant, and pigeon) in North-Western Spain were tested for susceptibility to 14 antimicrobials by the disc diffusion method. All strains showed a multi-resistant phenotype (resistance to between three and 10 antimicrobials). The strains exhibited high percentages of resistance to erythromycin (89.1%), tetracycline (67.3%), ciprofloxacin (92.7%), nitrofurantoin (67.3%), and quinupristin-dalfopristin (81.8%). The lowest values (9.1%) were observed for high-level resistance to gentamicin, kanamycin, and streptomycin. The average number of resistances per strain was 5.8 for E. faecium isolates, 7.9 for E. faecalis, and 5.7 for E. durans. Genes encoding antimicrobial resistance and virulence were studied by polymerase chain reaction. A total of 15 (57.7%) of the 26 vancomycin-resistant isolates harboured the vanA gene. Other resistance genes detected included vanB, erm(B) and/or erm(C), tet(L) and/or tet(M), acc(6')-aph(2″), and aph(3')-IIIa in strains resistant to vancomycin, erythromycin, tetracycline, gentamicin, and kanamycin, respectively. Specific genes of the Tn5397 transposon were detected in 54.8% of the tet(M)-positive enterococci. Nine virulence factors (gelE, agg, ace, cpd, frs, esp, hyl, efaAfs and efaAfm) were studied. All virulence genes, with the exception of the frs gene, were found to be present in the enterococcal isolates. At least one virulence gene was detected in 20.0% of E. faecium, 71.4% of E. faecalis and 33.3% of E. durans isolates, with ace and cpd being the most frequently detected genes (6 isolates each). This suggests that wild game meat might play a role in the spreading through the food chain of enterococci with antimicrobial resistance and virulence determinants to humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fidaxomicin versus vancomycin for Clostridium difficile infection: meta-analysis of pivotal randomized controlled trials.

Science.gov (United States)

Crook, Derrick W; Walker, A Sarah; Kean, Yin; Weiss, Karl; Cornely, Oliver A; Miller, Mark A; Esposito, Roberto; Louie, Thomas J; Stoesser, Nicole E; Young, Bernadette C; Angus, Brian J; Gorbach, Sherwood L; Peto, Timothy E A

2012-08-01

Two recently completed phase 3 trials (003 and 004) showed fidaxomicin to be noninferior to vancomycin for curing Clostridium difficile infection (CDI) and superior for reducing CDI recurrences. In both studies, adults with active CDI were randomized to receive blinded fidaxomicin 200 mg twice daily or vancomycin 125 mg 4 times a day for 10 days. Post hoc exploratory intent-to-treat (ITT) time-to-event analyses were undertaken on the combined study 003 and 004 data, using fixed-effects meta-analysis and Cox regression models. ITT analysis of the combined 003/004 data for 1164 patients showed that fidaxomicin reduced persistent diarrhea, recurrence, or death by 40% (95% confidence interval [CI], 26%-51%; P < .0001) compared with vancomycin through day 40. A 37% (95% CI, 2%-60%; P = .037) reduction in persistent diarrhea or death was evident through day 12 (heterogeneity P = .50 vs 13-40 days), driven by 7 (1.2%) fidaxomicin versus 17 (2.9%) vancomycin deaths at <12 days. Low albumin level, low eosinophil count, and CDI treatment preenrollment were risk factors for persistent diarrhea or death at 12 days, and CDI in the previous 3 months was a risk factor for recurrence (all P < .01). Fidaxomicin has the potential to substantially improve outcomes from CDI.

Clinical response and hospital costs associated with the empirical use of vancomycin and linezolid for hospital-acquired pneumonia in a Chinese tertiary care hospital: a retrospective cohort study

Directory of Open Access Journals (Sweden)

Song Y

2014-10-01

a nonsignificant trend of lower risk of in-hospital mortality associated with vancomycin (odds ratio: 0.186; P=0.055. The total hospital costs associated with vancomycin had a nonsignificant trend of being lower, likely because of its significantly lower acquisition costs (median: RMB 2,880 versus RMB 8,194; P<0.001; 1 RMB =0.16 USD. Conclusion: In tertiary care hospitals in the People's Republic of China, empirical treatment of patients with HAP with vancomycin had a comparable treatment failure rate but likely had a lower in-hospital mortality rate when compared with linezolid. Vancomycin also costs significantly less for drug acquisition than linezolid when treating HAP empirically. Keywords: methicillin-resistant Staphylococcus aureus, treatment failure, mortality, antibiotics

Impact of oral vancomycin on gut microbiota, bile acid metabolism, and insulin sensitivity

DEFF Research Database (Denmark)

Vrieze, Anne; Out, Carolien; Fuentes, Susana

2014-01-01

.i.d. At baseline and after 1 week of therapy, fecal microbiota composition (Human Intestinal Tract Chip phylogenetic microarray), fecal and plasma bile acid concentrations as well as insulin sensitivity (hyperinsulinemic euglycemic clamp using [6,6-(2)H2]-glucose tracer) were measured. RESULTS: Vancomycin reduced...... (pinsulin sensitivity (p... of vancomycin significantly impacts host physiology by decreasing intestinal microbiota diversity, bile acid dehydroxylation and peripheral insulin sensitivity in subjects with metabolic syndrome. These data show that intestinal microbiota, particularly of the Firmicutes phylum contributes to bile acid...

Cost-effectiveness analysis evaluating fidaxomicin versus oral vancomycin for the treatment of Clostridium difficile infection in the United States.

Science.gov (United States)

Stranges, Paul M; Hutton, David W; Collins, Curtis D

2013-01-01

Fidaxomicin is a novel treatment for Clostridium difficile infections (CDIs). This new treatment, however, is associated with a higher acquisition cost compared with alternatives. The objective of this study was to evaluate the cost-effectiveness of fidaxomicin or oral vancomycin for the treatment of CDIs. We performed a cost-utility analysis comparing fidaxomicin with oral vancomycin for the treatment of CDIs in the United States by creating a decision analytic model from the third-party payer perspective. The incremental cost-effectiveness ratio with fidaxomicin compared with oral vancomycin was $67,576/quality-adjusted life-year. A probabilistic Monte Carlo sensitivity analysis showed that fidaxomicin had an 80.2% chance of being cost-effective at a willingness-to-pay threshold of $100,000/quality-adjusted life-year. Fidaxomicin remained cost-effective under all fluctuations of both fidaxomicin and oral vancomycin costs. The decision analytic model was sensitive to variations in clinical cure and recurrence rates. Secondary analyses revealed that fidaxomicin was cost-effective in patients receiving concominant antimicrobials, in patients with mild to moderate CDIs, and when compared with oral metronidazole in patients with mild to moderate disease. Fidaxomicin was dominated by oral vancomycin if CDI was caused by the NAP1/Bl/027 Clostridium difficile strain and was dominant in institutions that did not compound oral vancomycin. Results of our model showed that fidaxomicin may be a more cost-effective option for the treatment of CDIs when compared with oral vancomycin under most scenarios tested. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Enantioseparation of dansyl amino acids by HPLC on a monolithic column dynamically coated with a vancomycin derivative.

Science.gov (United States)

Pittler, Elfriede; Schmid, Martin G

2010-11-01

In this work a chiral stationary phase was prepared by dynamically coating a monolithic reversed-phase HPLC column with a vancomycin-derivative as chiral selector. A hydrophobic alkyl-chain was attached to the vancomycin molecule, providing the immobilization of the chiral selector on the reversed-phase material. Dansyl amino acids were chosen as model analytes for testing the separation power of the dynamically coated phase. All investigated compounds were separated into their enantiomers. Compared with a conventionally packed vancomycin-CSP, a reversal of the enantiomer elution order was obtained. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of dual delivery of antibiotics (vancomycin and cefazolin) and BMP-7 from chitosan microparticles on Staphylococcus epidermidis and pre-osteoblasts in vitro

Energy Technology Data Exchange (ETDEWEB)

Mantripragada, Venkata P. [Biomedical Engineering Program, The University of Toledo, Toledo, OH 43614-5807 (United States); Jayasuriya, Ambalangodage C., E-mail: a.jayasuriya@utoledo.edu [Biomedical Engineering Program, The University of Toledo, Toledo, OH 43614-5807 (United States); Department of Orthopaedic Surgery, The University of Toledo, Toledo, OH 43614-5807 (United States)

2016-10-01

The main aims of this manuscript are to: i) determine the effect of commonly used antibiotics to treat osteoarticular infections on osteoblast viability, ii) study the dual release of the growth factor (BMP-7) and antibiotics (vancomycin and cefazolin) from chitosan microparticles iii) demonstrate the bioactivity of the antibiotics released in vitro on Staphylococcus epidermidis. The novelty of this work is dual delivery of growth factor and antibiotic from the chitosan microparticles in a controlled manner without affecting their bioactivity. Cefazolin and vancomycin have different therapeutic concentrations for their action in vivo and therefore, two different concentrations of the drugs were used. Osteoblast cytotoxicity test concluded that cefazolin concentrations of 50 and 100 μg/ml were found to have positive influence on osteoblast proliferation. A significant increase in osteoblast proliferation was observed in the presence of cefazolin and BMP-7 in comparison with BMP-7 alone group; indicating cefazolin might play a role in osteoblast proliferation. On the other hand, vancomycin concentration of 1000 μg/ml was found to significantly reduce (p < 0.01) osteoblast proliferation in comparison with controls. The microbial study indicated that cefazolin at a minimum concentration of 21.5 μg/ml could inhibit ~ 85% growth of S. epidermidis, whereas vancomycin at a concentration of 30 μg/ml was found to inhibit ~ 80% bacterial growth. - Highlights: • Bacterial infections involve the inflammatory destruction of joint and bone. • Vancomycin and cefazolin half-life is limited to a few hours. • Dual delivery of growth factor and antibiotic from the chitosan microparticles. • Bioactivity of antibiotics released by the microparticles was protected.

Effect of dual delivery of antibiotics (vancomycin and cefazolin) and BMP-7 from chitosan microparticles on Staphylococcus epidermidis and pre-osteoblasts in vitro

International Nuclear Information System (INIS)

Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

2016-01-01

The main aims of this manuscript are to: i) determine the effect of commonly used antibiotics to treat osteoarticular infections on osteoblast viability, ii) study the dual release of the growth factor (BMP-7) and antibiotics (vancomycin and cefazolin) from chitosan microparticles iii) demonstrate the bioactivity of the antibiotics released in vitro on Staphylococcus epidermidis. The novelty of this work is dual delivery of growth factor and antibiotic from the chitosan microparticles in a controlled manner without affecting their bioactivity. Cefazolin and vancomycin have different therapeutic concentrations for their action in vivo and therefore, two different concentrations of the drugs were used. Osteoblast cytotoxicity test concluded that cefazolin concentrations of 50 and 100 μg/ml were found to have positive influence on osteoblast proliferation. A significant increase in osteoblast proliferation was observed in the presence of cefazolin and BMP-7 in comparison with BMP-7 alone group; indicating cefazolin might play a role in osteoblast proliferation. On the other hand, vancomycin concentration of 1000 μg/ml was found to significantly reduce (p < 0.01) osteoblast proliferation in comparison with controls. The microbial study indicated that cefazolin at a minimum concentration of 21.5 μg/ml could inhibit ~ 85% growth of S. epidermidis, whereas vancomycin at a concentration of 30 μg/ml was found to inhibit ~ 80% bacterial growth. - Highlights: • Bacterial infections involve the inflammatory destruction of joint and bone. • Vancomycin and cefazolin half-life is limited to a few hours. • Dual delivery of growth factor and antibiotic from the chitosan microparticles. • Bioactivity of antibiotics released by the microparticles was protected.

Repeated batch production of vancomycin using synthetic cotton fibers

African Journals Online (AJOL)

Administrator

2011-09-28

Sep 28, 2011 ... The production of vancomycin by free and immobilized cells of Amycolatopsis orientalis was .... ceutical Industries Company (EIPICO)] and the inhibition zone ... production medium showed a marked loss in the first ... secondary metabolic enzymes of immobilized cells, as ... of cells in an economic way.

Experimental and Theoretical Studies of the Structures and Interactions of Vancomycin Antibiotics with Cell Wall Analogues

International Nuclear Information System (INIS)

Yang, Zhibo; Vorpagel, Erich R.; Laskin, Julia

2008-01-01

Surface-induced dissociation (SID) of the singly protonated complex of vancomycin antibiotic with cell wall peptide analogue (N α , N # var e psilon#-diacetyl-L-Lys-D-Ala-D-Ala) was studied using a 6 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS) specially configured for SID experiments. The binding energy between the vancomycin and the peptide was obtained from the RRKM modeling of the time- and energy resolved fragmentation efficiency curves (TFECs) of the precursor ion and its fragments. Electronic structure calculations of the geometries, proton affinities and binding energies were performed for several model systems including vancomycin (V), vancomycin aglycon (VA), N α , N # var e psilon#-diacetyl-L-Lys-D-Ala-D-Ala, and non-covalent complexes of VA with N-acetyl-D-Ala-D-Ala and N α , N # var e psilon#-diacetyl-L-Lys-D-Ala-D-Ala at the B3LYP/6-31G(d) level of theory. Comparison between the experimental and computational results suggests that the most probable structure of the complex observed in our experiments corresponds to the neutral peptide bound to the vancomycin protonated at the secondary amino group of the N-methyl-leucine residue. The experimental binding energy of 30.9 ± 1.8 kcal/mol is in good agreement with the binding energy of 29.3 ± 2.5 kcal/mol calculated for the model system representing the preferred structure of the complex

Comparison of the Effectiveness and Safety of Linezolid and Daptomycin in Vancomycin-Resistant Enterococcal Bloodstream Infection: A National Cohort Study of Veterans Affairs Patients.

Science.gov (United States)

Britt, Nicholas S; Potter, Emily M; Patel, Nimish; Steed, Molly E

2015-09-15

Vancomycin-resistant Enterococcus bloodstream infections (VRE-BSIs) are becoming increasingly common. Linezolid and daptomycin are the primary treatment options for VRE-BSI, but optimal treatment is unclear. This was a national retrospective cohort study comparing linezolid and daptomycin for the treatment of VRE-BSI among Veterans Affairs Medical Center patients admitted during 2004-2013. The primary outcome was treatment failure, defined as a composite of (1) 30-day all-cause mortality; (2) microbiologic failure; and (3) 60-day VRE-BSI recurrence. Poisson regression was conducted to determine if antimicrobial treatment was independently associated with clinical outcomes. A total of 644 patients were included (linezolid, n = 319; daptomycin, n = 325). Overall, treatment failure was 60.9% (n = 392/644), and 30-day all-cause mortality was 38.2% (n = 246/644). Linezolid was associated with a significantly higher risk of treatment failure compared with daptomycin (risk ratio [RR], 1.37; 95% confidence interval [CI], 1.13-1.67; P = .001). After adjusting for confounding factors in Poisson regression, the relationship between linezolid use and treatment failure persisted (adjusted RR, 1.15; 95% CI, 1.02-1.30; P = .026). Linezolid was also associated with higher 30-day mortality (42.9% vs 33.5%; RR, 1.17; 95% CI, 1.04-1.32; P = .014) and microbiologic failure rates (RR, 1.10; 95% CI, 1.02-1.18; P = .011). No difference in 60-day VRE-BSI recurrence was observed between treatment groups. Treatment with linezolid for VRE-BSI resulted in significantly higher treatment failure in comparison to daptomycin. Linezolid treatment was also associated with greater 30-day all-cause mortality and microbiologic failure in this cohort. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Estratégias utilizadas no combate a resistência bacteriana Recent achievements to combat bacterial resistance

OpenAIRE

Gustavo Pozza Silveira; Faruk Nome; José Carlos Gesser; Marcus Mandolesi Sá; Hernán Terenzi

2006-01-01

This article provides an overview on the recent achievements to combat Gram-positive bacteria and the mechanisms related to antimicrobial activity and bacterial resistance. Selected synthetic methodologies to access structurally diverse bioactive compounds are presented in order to emphasize the most important substances currently developed to overcome multiresistant strains. The main properties of vancomycin and related glycopeptide antibiotics are also discussed as a background to understan...

Significant reduction in vancomycin-resistant enterococcus colonization and bacteraemia after introduction of a bleach-based cleaning-disinfection programme.

Science.gov (United States)

Grabsch, E A; Mahony, A A; Cameron, D R M; Martin, R D; Heland, M; Davey, P; Petty, M; Xie, S; Grayson, M L

2012-12-01

Vancomycin-resistant enterococcus (VRE) colonization and infection have increased at our hospital, despite adherence to standard VRE control guidelines. We implemented a multi-modal, hospital-wide improvement programme including a bleach-based cleaning-disinfection programme ('Bleach-Clean'). VRE colonization, infection and environmental contamination were compared pre and post implementation. The programme included a new product (sodium hypochlorite 1000 ppm + detergent), standardized cleaning-disinfection practices, employment of cleaning supervisors, and modified protocols to rely on alcohol-based hand hygiene and sleeveless aprons instead of long-sleeved gowns and gloves. VRE was isolated using chromogenic agar and/or routine laboratory methods. Outcomes were assessed during the 6 months pre and 12 months post implementation, including proportions (per 100 patients screened) of VRE colonization in high-risk wards (HRWs: intensive care, liver transplant, renal, haematology/oncology); proportions of environmental contamination; and episodes of VRE bacteraemia throughout the entire hospital. Significant reductions in newly recognized VRE colonizations (208/1948 patients screened vs 324/4035, a 24.8% reduction, P = 0.001) and environmental contamination (66.4% reduction, P = 0.012) were observed, but the proportion of patients colonized on admission was stable. The total burden of inpatients with VRE in the HRWs also declined (median percentage of colonized inpatients per week, 19.4% vs 17.3%, P = 0.016). Hospital-wide VRE bacteraemia declined from 14/2935 patients investigated to 5/6194 (83.1% reduction; P Clean programme was associated with marked reductions in new VRE colonizations in high-risk patients, and VRE bacteraemia across the entire hospital. These findings have important implications for VRE control in endemic healthcare settings. Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Rapid Emergence of Resistance to Linezolid during Linezolid Therapy of an Enterococcus faecium Infection▿

OpenAIRE

Seedat, Jamela; Zick, Günther; Klare, Ingo; Konstabel, Carola; Weiler, Norbert; Sahly, Hany

2006-01-01

We report the emergence of linezolid resistance (MICs of 16 to 32 mg/liter) in clonally related vancomycin-susceptible and -resistant Enterococcus faecium isolates from an intensive care unit patient after 12 days of linezolid therapy. Only linezolid-susceptible isolates of the same clone were detected at 28 days after termination of linezolid therapy.

Serine and alanine racemase activities of VanT: a protein necessary for vancomycin resistance in Enterococcus gallinarum BM4174.

Science.gov (United States)

Arias, C A; Weisner, J; Blackburn, J M; Reynolds, P E

2000-07-01

Vancomycin resistance in Enterococcus gallinarum results from the production of UDP-MurNAc-pentapeptide[D-Ser]. VanT, a membrane-bound serine racemase, is one of three proteins essential for this resistance. To investigate the selectivity of racemization of L-Ser or L-Ala by VanT, a strain of Escherichia coli TKL-10 that requires D-Ala for growth at 42 degrees C was used as host for transformation experiments using plasmids containing the full-length vanT from Ent. gallinarum or the alanine racemase gene (alr) of Bacillus stearothermophilus: both plasmids were able to complement E. coli TKL-10 at 42 degrees C. No alanine or serine racemase activities were detected in the host strain E. coli TKL-10 grown at 30, 34 or 37 degrees C. Serine and alanine racemase activities were found almost exclusively (96%) in the membrane fraction of E. coli TKL-10/pCA4(vanT): the alanine racemase activity of VanT was 14% of the serine racemase activity in both E. coli TKL-10/pCA4(vanT) and E. coli XL-1 Blue/pCA4(vanT). Alanine racemase activity was present mainly (95%) in the cytoplasmic fraction of E. coli TKL-10/pJW40(alr), with a trace (1.6%) of serine racemase activity. Additionally, DNA encoding the soluble domain of VanT was cloned and expressed in E. coli M15 as a His-tagged polypeptide and purified: this polypeptide also exhibited both serine and alanine racemase activities; the latter was approximately 18% of the serine racemase activity, similar to that of the full-length, membrane-bound enzyme. N-terminal sequencing of the purified His-tagged polypeptide revealed a single amino acid sequence, indicating that the formation of heterodimers between subunits of His-tagged C-VanT and endogenous alanine racemases from E. coli was unlikely. The authors conclude that the membrane-bound serine racemase VanT also has alanine racemase activity but is able to racemize serine more efficiently than alanine, and that the cytoplasmic domain is responsible for the racemase activity.

A meta-analysis of metronidazole and vancomycin for the treatment of Clostridium difficile infection, stratified by disease severity.

Science.gov (United States)

Di, Xiuzhen; Bai, Nan; Zhang, Xin; Liu, Bin; Ni, Wentao; Wang, Jin; Wang, Kai; Liang, Beibei; Liu, Youning; Wang, Rui

2015-01-01

The aim of this meta-analysis was to compare the efficacy of metronidazole and vancomycin for the treatment of Clostridium difficile infection, especially to investigate which agent was superior for treating either mild or severe C. difficile infection. A meta-analysis of randomized controlled trials and cohort studies identified in Pubmed, Embase, and the Cochrane Library was conducted. Four randomized controlled trials and two cohort studies involving 1218 patients were included in this meta-analysis. Metronidazole was inferior to vancomycin for treating C. difficile infection in terms of both initial clinical cure rates (risk ratio, RR=0.91, 95% confidence interval, CI=0.84-0.98, p=0.02) and sustained cure rates (RR=0.88, 95% CI=0.82-0.96, p=0.003). For mild C. difficile infection, the efficacy of metronidazole and vancomycin resulted in similar clinical cure rates (RR=0.94, 95% CI=0.84-1.04, p=0.21) and sustained cure rates (RR=0.93, 95% CI=0.83-1.05, p=0.26). For severe C. difficile infection the efficacy of vancomycin was superior to metronidazole in terms of clinical cure rates (RR=0.81, 95% CI=0.69-0.95, p=0.009), whereas sustained cure rates were similar (RR=0.86, 95% CI=0.72-1.02, p=0.08). Regarding microbiological cure metronidazole therapy was as effective as vancomycin therapy (RR=0.88, 95% CI=0.64-1.21, p=0.43). Recurrence rates with metronidazole and vancomycin for both mild C. difficile infection (RR=0.95, 95% CI=0.56-1.60, p=0.85) and severe C. difficile infection (RR=1.27, 95% CI=0.85-1.91, p=0.25) were not different. Likewise, no difference in all-cause mortality was found as well (RR=0.87, 95% CI=0.56-1.35, p=0.53). In conclusion, vancomycin provides improved initial clinical and sustained cure rates in patients with C. difficile infection compared with metronidazole, especially in patients with severe C. difficile infection. In view of these data, vancomycin may be considered first line therapy for severe C. difficile infection. Copyright �

Antibiotic Resistance in Childhood with Pneumococcal Infection

Directory of Open Access Journals (Sweden)

Ali Gunes

2013-10-01

Full Text Available Aim: Resistance to antibiotics is better. Between should not be in capitals. Antibiotics resistant has been increasing in pneumococci that cause serious diseases such as pneumonia, meningitis in recent years. The resistance rates vary between geographic regions. In this study, we aimed to determine antibiotic resistance rates in pneumococcal infections in our region. Material and Method: This study included 31 pneumococcal strains isolated from blood, CSF and urine samples of patients with meningitis, sepsis and urinary tract infections who admitted Dicle University Medicine School Children Clinic and Diyarbakir Pediatric Hospital Between December 2004-April 2007. Reproducing clinical specimens with alpha-hemolysis, optochin-sensitive, bile soluble and gram-positive diplococci morphology was defined as S. pneumoniae. The antimicrobial susceptibilities of strains were measured by the E-test method. MIC values of penicillin against pneumococci was accepted as <0.06 mg / ml value of the sensitive, 0.12-1μg/ml mid-level resistance, ≥ 2 mg / ml value of the high-level resistance. Results: It was found 16% mid-level penicillin resistance and 3.2% high-level penicillin resistance by E-test method. 80.7% of Strains were percent of the penicillin-sensitive. Seftiriakson resistance was found as 3.2%. there was not Vancomycin resistance. Discussion: We think penicillin therapy is enough effective for pneumococcal infections except serious conditions such as meningitis and sepsis. Also we think it should be supported by multicenter studies.

High prevalence of multidrug-resistant MRSA in a tertiary care hospital of northern India

Directory of Open Access Journals (Sweden)

Hare Krishna Tiwari

2008-11-01

Full Text Available Hare Krishna Tiwari1, Darshan Sapkota2, Malaya Ranjan Sen11Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, UP, India; 2Department of Microbiology, Universal College of Medical Sciences, Bhairahawa, NepalAbstract: Methicillin-resistant Staphylococcus aureus (MRSA is an important nosocomial and community pathogen. The objectives of this study were to estimate the prevalence of multidrug-resistant MRSA strains in clinical specimens and to investigate the sensitivity pattern of these strains against various antibiotics used for treating hospitalized and out patients. Strains were identified using standard procedures, and their sensitivity pattern was investigated using such techniques as disc diffusion, minimum inhibitory concentration (MIC, and the mecA gene PCR. Among 783 isolates of S. aureus, 301 (38.44% were methicillin-resistant, of which 217 (72.1% were found to be multidrug-resistant. Almost all MRSA strains were resistant to penicillin, 95.68% were resistant to cotrimoxazole, 92.36% were resistant to chloramphenicol, 90.7% were resistant to norfloxacin, 76.1% were resistant to tetracycline, and 75.75% were resistant to ciprofloxacin. Vancomycin was the most effective drug, with only 0.33% of MRSA strains being resistant to it. It is concluded that antibiotics other than vancomycin can be used as anti-MRSA agents after a sensitivity test so as to preclude the emergence of resistance to it and that prevailing problems in chemotherapy will escalate unless indiscriminate and irrational usage of antibiotics is checked.Keywords: multidrug-resistant MRSA, prevalence, India

Pharmacist-managed dose adjustment feedback using therapeutic drug monitoring of vancomycin was useful for patients with methicillin-resistant Staphylococcus aureus infections: a single institution experience

Directory of Open Access Journals (Sweden)

Hirano R

2016-10-01

Full Text Available Ryuichi Hirano,1 Yuichi Sakamoto,2 Junichi Kitazawa,2 Shoji Yamamoto,1 Naoki Tachibana2 1Department of Pharmacy, 2Laboratory Medicine and Blood Transfusion, Aomori Prefectural Central Hospital, Aomori-shi, Japan Background: Vancomycin (VCM requires dose adjustment based on therapeutic drug monitoring. At Aomori Prefectural Central Hospital, physicians carried out VCM therapeutic drug monitoring based on their experience, because pharmacists did not participate in the dose adjustment. We evaluated the impact of an Antimicrobial Stewardship Program (ASP on attaining target VCM trough concentrations and pharmacokinetics (PK/pharmacodynamics (PD parameters in patients with methicillin-resistant Staphylococcus aureus (MRSA infections. Materials and methods: The ASP was introduced in April 2012. We implemented a prospective audit of prescribed VCM dosages and provided feedback based on measured VCM trough concentrations. In a retrospective pre- and postcomparison study from April 2007 to December 2011 (preimplementation and from April 2012 to December 2014 (postimplementation, 79 patients were treated for MRSA infection with VCM, and trough concentrations were monitored (pre, n=28; post, n=51. In 65 patients (pre, n=15; post, n=50, 24-hour area under the ­concentration–time curve (AUC 0–24 h/minimum inhibitory concentration (MIC ratios were calculated. Results: Pharmacist feedback, which included recommendations for changing dose or using alternative anti-MRSA antibiotics, was highly accepted during postimplementation (88%, 29/33. The number of patients with serum VCM concentrations within the therapeutic range (10–20 μg/mL was significantly higher during postimplementation (84%, 43/51 than during preimplementation (39%, 11/28 (P<0.01. The percentage of patients who attained target PK/PD parameters (AUC 0–24 h/MIC >400 was significantly higher during postimplementation (84%, 42/50 than during preimplementation (53%, 8/15; P=0.013. There were

Antimicrobial resistance in Libya: 1970–2011

Directory of Open Access Journals (Sweden)

Khalifa Sifaw Ghenghesh

2013-03-01

Full Text Available Resistance to antimicrobial agents is a major health problem that affects the whole world. Providing information on the past state of antimicrobial resistance in Libya may assist the health authorities in addressing the problem more effectively in the future. Information was obtained mainly from Highwire Press (including PubMed search for the period 1970–2011 using the terms ‘antibiotic resistance in Libya’, ‘antimicrobial resistance in Libya’, ‘tuberculosis in Libya’, and ‘primary and acquired resistance in Libya’ in title and abstract. From 1970 to 2011 little data was available on antimicrobial resistance in Libya due to lack of surveillance and few published studies. Available data shows high resistance rates for Salmonella species in the late 1970s and has remained high to the present day. High prevalence rates (54–68% of methicillin-resistant Staphylococcus aureus (MRSA were reported in the last decade among S. aureus from patients with burns and surgical wound infections. No reports were found of vancomycin-resistant S. aureus (VRSA or vancomycin-intermediate-resistant S. aureus (VISA using standard methods from Libya up to the end of 2011. Reported rates of primary (i.e. new cases and acquired (i.e. retreatment cases multidrug-resistant tuberculosis (MDR-TB from the eastern region of Libya in 1971 were 16.6 and 33.3% and in 1976 were 8.6 and 14.7%, in western regions in 1984–1986 were 11 and 21.5% and in the whole country in 2011 were estimated at 3.4 and 29%, respectively. The problem of antibiotic resistance is very serious in Libya. The health authorities in particular and society in general should address this problem urgently. Establishing monitoring systems based on the routine testing of antimicrobial sensitivity and education of healthcare workers, pharmacists, and the community on the health risks associated with the problem and benefits of prudent use of antimicrobials are some steps that can be taken to

Impacto de la resistencia a la meticilina sobre la mortalidad y vigilancia de la sensibilidad a la vancomicina en bacteriemias causadas por Staphylococcus aureus Impact of methicillin resistance on mortality and surveillance of vancomycin susceptibility in bacteremias caused by Staphylococcus aureus

Directory of Open Access Journals (Sweden)

F. Traverso

2010-12-01

Full Text Available Staphylococcus aureus es uno de los principales patógenos nosocomiales y produce una alta morbimortalidad en numerosos hospitales del mundo. Además, la incidencia de bacteriemias por este microorganismo ha aumentado significativamente en las últimas décadas. Los objetivos del presente trabajo fueron identificar los factores de riesgo que favorecen la aparición de resistencia a la meticilina en aislamientos de S. aureus y los factores que afectan la mortalidad por bacteriemias asociadas a este patógeno, así como evaluar la sensibilidad a la vancomicina de las cepas resistentes a la meticilina. Se estudiaron 39 aislamientos de S. aureus provenientes de hemocultivos de pacientes internados con bacteriemia en la Nueva Clínica Chacabuco de Tandil (Pcia. de Buenos Aires, Argentina en el período 01/2006-12/2008. La mortalidad global fue del 51,3% y estuvo significativamente asociada con la resistencia a la meticilina (OR: 4,20; IC95%: 1,08-16,32; p: 0,05; aunque dicho factor no fue un predictor independiente de mortalidad. La cirugía previa (OR: 17,23; IC95%: 1,80-164,60 y la estancia previa en la unidad de cuidados intensivos (OR: 21,12; IC95%: 2,33-191,30 fueron predictores independientes de la resistencia a la meticilina y la asistencia respiratoria mecánica (OR: 15,99; IC: 3,24-78,86 fue un predictor independiente de la mortalidad. No se detectaron cepas con sensibilidad disminuida a la vancomicina. Todos los aislamientos estudiados fueron sensibles in vitro a la vancomicina, con una CIM50 y una CIM90 de 0,5 μg/ml.Staphylococcus aureus is a major nosocomial pathogen that causes severe morbidity and mortality in many hospitals worldwide. Besides, the incidence of S. aureus bacteremia has significantly increased over the past decades. The aims of this study were to detect the risk factors for methicillin resistance and mortality and to evaluate vancomycin susceptibility in methicillin-resistant isolates. Thus, 39 S. aureus isolates from

High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus

Science.gov (United States)

Viedma, Esther; Chaves, Fernando; Lalueza, Antonio; Fortún, Jesús; Loza, Elena; Pujol, Miquel; Ardanuy, Carmen; Morales, Isabel; de Cueto, Marina; Resino-Foz, Elena; Morales-Cartagena, Alejandra; Rico, Alicia; Romero, María P.; Orellana, María Ángeles; López-Medrano, Francisco; Fernández-Ruiz, Mario; Aguado, José María

2016-01-01

We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011–June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 μg/mL and 0.5 μg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2–5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1–5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications. PMID:27192097

Convergent acquisition of antibiotic resistance determinants ...

African Journals Online (AJOL)

Convergent acquisition of antibiotic resistance determinants amongst the Enterobacteriaceae isolates of the Mhlathuze River, KwaZulu-Natal (RSA) ... The possibility of transmission of resistant genes between bacteria (especially pathogenic) which invade human and animal populations within this river poses a health risk ...

Vancomycin resistance in Enterococcus faecium isolated from Danish chicken meat is located on a pVEF4-like plasmid persisting in poultry for 18 years

DEFF Research Database (Denmark)

Leinweber, Helena Augusta Katharina; Alotaibi, Sulaiman Mohammed I; Overballe-Petersen, Søren

2018-01-01

traits of VREfm in Danish retail chicken meat. Three out of 40 samples (7.5%) from two slaughterhouses yielded VREfm (vancomycin MIC > 32mg/L). This is the first report of VREfm in Danish retail poultry meat since 2010 (DANMAP). All three VREfm belonged to the sequence type ST32, cluster type CT1068...

Occurrence of transferable antibiotic resistances in commercialized ready-to-eat mealworms (Tenebrio molitor L.).

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Osimani, Andrea; Cardinali, Federica; Aquilanti, Lucia; Garofalo, Cristiana; Roncolini, Andrea; Milanović, Vesna; Pasquini, Marina; Tavoletti, Stefano; Clementi, Francesca

2017-12-18

The present study aimed to assess the occurrence of transferable determinants conferring resistance to tetracyclines, macrolide-lincosamide-streptogramin B, vancomycin, beta-lactams, and aminoglycosides in 40 samples of commercialized edible mealworms (Tenebrio molitor L.) purchased from European Union (EU) and non-EU producers. A high prevalence of tet(K) was observed in all of the samples assayed, with percentages of PCR-based positivity that ranged from 80% (samples from Thailand) to 100% (samples from the Netherlands, Belgium and France). For macrolides, erm(B) prevailed, being detected in 57.5% of the samples assayed, whereas erm(A) and erm(C) were detected with lower frequencies. Genes for resistance to vancomycin were only detected in samples produced in France and Belgium, with 90% and 10% of the samples being positive for vanA, respectively. Beta-lactamase genes were found with low occurrence, whereas the gene aac-aph, conferring high resistance to aminoglycosides, was found in 40% of the samples produced in the Netherlands and Belgium and 20% of the samples produced in Thailand. The results of Principal Coordinate Analysis and Principal Component Analysis depicted a clean separation of the samples collected from the four producers based on the distribution of the 12 AR determinants considered. Given the growing interest on the use of mealworms as a novel protein source, AR detection frequencies found in the present study suggest further investigation into the use of antibiotics during rearing of this insect species and more extensive studies focused on the factors that can affect the diffusion of transferable ARs in the production chain. Until such studies are completed, prudent use of antibiotics during rearing of edible insects is recommended. Copyright © 2017 Elsevier B.V. All rights reserved.

Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

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Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

2012-06-01

The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

Treatment of osteomyelitis defects by a vancomycin-loaded gelatin/β-tricalcium phosphate composite scaffold

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Zhou, J.; Zhou, X. G.; Wang, J. W.; Zhou, H.; Dong, J.

2018-01-01

Objective In the present study, we aimed to assess whether gelatin/β-tricalcium phosphate (β-TCP) composite porous scaffolds could be used as a local controlled release system for vancomycin. We also investigated the efficiency of the scaffolds in eliminating infections and repairing osteomyelitis defects in rabbits. Methods The gelatin scaffolds containing differing amounts of of β-TCP (0%, 10%, 30% and 50%) were prepared for controlled release of vancomycin and were labelled G-TCP0, G-TCP1, G-TCP3 and G-TCP5, respectively. The Kirby-Bauer method was used to examine the release profile. Chronic osteomyelitis models of rabbits were established. After thorough debridement, the osteomyelitis defects were implanted with the scaffolds. Radiographs and histological examinations were carried out to investigate the efficiency of eliminating infections and repairing bone defects. Results The prepared gelatin/β-TCP scaffolds exhibited a homogeneously interconnected 3D porous structure. The G-TCP0 scaffold exhibited the longest duration of vancomycin release with a release duration of eight weeks. With the increase of β-TCP contents, the release duration of the β-TCP-containing composite scaffolds was decreased. The complete release of vancomycin from the G-TCP5 scaffold was achieved within three weeks. In the treatment of osteomyelitis defects in rabbits, the G-TCP3 scaffold showed the most efficacious performance in eliminating infections and repairing bone defects. Conclusions The composite scaffolds could achieve local therapeutic drug levels over an extended duration. The G-TCP3 scaffold possessed the optimal porosity, interconnection and controlled release performance. Therefore, this scaffold could potentially be used in the treatment of chronic osteomyelitis defects. Cite this article: J. Zhou, X. G. Zhou, J. W. Wang, H. Zhou, J. Dong. Treatment of osteomyelitis defects by a vancomycin-loaded gelatin/β-tricalcium phosphate composite scaffold. Bone Joint Res

Characterization of Antibiotic Resistance Genes from Lactobacillus Isolated from Traditional Dairy Products.

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Guo, Huiling; Pan, Lin; Li, Lina; Lu, Jie; Kwok, Laiyu; Menghe, Bilige; Zhang, Heping; Zhang, Wenyi

2017-03-01

Lactobacilli are widely used as starter cultures or probiotics in yoghurt, cheese, beer, wine, pickles, preserved food, and silage. They are generally recognized as safe (GRAS). However, recent studies have shown that some lactic acid bacteria (LAB) strains carry antibiotic resistance genes and are resistant to antibiotics. Some of them may even transfer their intrinsic antibiotic resistance genes to other LAB or pathogens via horizontal gene transfer, thus threatening human health. A total of 33 Lactobacillus strains was isolated from fermented milk collected from different areas of China. We analyzed (1) their levels of antibiotic resistance using a standardized dilution method, (2) their antibiotic resistance gene profiles by polymerase chain reaction (PCR) using gene-specific primers, and (3) the transferability of some of the detected resistance markers by a filter mating assay. All Lactobacillus strains were found to be resistant to vancomycin, but susceptible to gentamicin, linezolid, neomycin, erythromycin, and clindamycin. Their susceptibilities to tetracycline, kanamycin, ciprofloxacin, streptomycin, quinupristin/dalfopristin, trimethoprim, ampicillin, rifampicin, and chloramphenicol was different. Results from our PCR analysis revealed 19 vancomycin, 10 ciprofloxacin, and 1 tetracycline-resistant bacteria that carried the van(X), van(E), gyr(A), and tet(M) genes, respectively. Finally, no transferal of the monitored antibiotic resistance genes was observed in the filter mating assay. Taken together, our study generated the antibiotic resistance profiles of some milk-originated lactobacilli isolates and preliminarily assessed their risk of transferring antibiotic gene to other bacteria. The study may provide important data concerning the safe use of LAB. © 2017 Institute of Food Technologists®.

Comparative Evaluation of Serotonin Toxicity among Veterans Affairs Patients Receiving Linezolid and Vancomycin

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Patel, N.; Rivera, A.; Tristani, L.; Lazariu, V.; Vandewall, H.; McNutt, L. A.

2013-01-01

Despite the theoretical risk of serotonin toxicity (ST) with linezolid, “real-world” clinical evaluations of the risk of ST in patients receiving linezolid have been limited to case reports and noncomparator studies. An observational, matched-cohort study was conducted to evaluate the risk of ST among hospitalized patients who received linezolid or vancomycin at the Upstate New York Veterans Affairs Healthcare Network (Veterans Integrated Service Network 2 [VISN-2]). Matching criteria included VISN-2 hospital, hospital ward, prior hospital length of stay, age, and baseline platelet counts. The patients' electronic medical records were evaluated for symptoms consistent with ST and the Hunter serotonin toxicity criteria (HSTC) using an intensive, natural word search algorithm. The study included 251 matched pairs. Demographics and comorbidities were similar between groups. Over half of the study population received at least one concurrent medication with serotonergic activity. Receipt of agents with serotonergic activity was more pronounced in the vancomycin group, and the higher frequency was due to concomitant antihistamine and antiemetic use. Antidepressant use, including selective serotonin reuptake inhibitors (SSRIs), was similar between groups. No patients in either group were found to meet the criteria using the word search algorithm for ST. Fewer linezolid patients than vancomycin patients met the HSTC overall (3.2% versus 8.8%) and when stratified by receipt of a concurrent serotonergic agent (4.3% versus 12.4%). Of the patients meeting the HSTC, most had past or present comorbidities that may have contributed to or overlapped the HSTC. This study of hospitalized patients revealed comparably low frequencies of adverse events potentially related to ST among patients who received linezolid or vancomycin. PMID:24041888

Prevalence and Genetic Basis of Antimicrobial Resistance in Non-aureus Staphylococci Isolated from Canadian Dairy Herds

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Nobrega, Diego B.; Naushad, Sohail; Naqvi, S. Ali; Condas, Larissa A. Z.; Saini, Vineet; Kastelic, John P.; Luby, Christopher; De Buck, Jeroen; Barkema, Herman W.

2018-01-01

Emergence and spread of antimicrobial resistance is a major concern for the dairy industry worldwide. Objectives were to determine: (1) phenotypic and genotypic prevalence of drug-specific resistance for 25 species of non-aureus staphylococci, and (2) associations between presence of resistance determinants and antimicrobial resistance. Broth micro-dilution was used to determine resistance profiles for 1,702 isolates from 89 dairy herds. Additionally, 405 isolates were sequenced to screen for resistance determinants. Antimicrobial resistance was clearly species-dependent. Resistance to quinupristin/dalfopristin was common in Staphylococcus gallinarum (prevalence of 98%), whereas S. cohnii and S. arlettae were frequently resistant to erythromycin (prevalence of 63 and 100%, respectively). Prevalence of resistance was 10% against β-lactams and tetracyclines. In contrast, resistance to antimicrobials critically important for human medicine, namely vancomycin, fluoroquinolones, linezolid and daptomycin, was uncommon (< 1%). Genes encoding multidrug-resistance efflux pumps and resistance-associated residues in deducted amino acid sequences of the folP gene were the most frequent mechanisms of resistance, regardless of species. The estimated prevalence of the mecA gene was 17% for S. epidermidis. Several genes, including blaZ, mecA, fexA, erm, mphC, msrA, and tet were associated with drug-specific resistance, whereas other elements were not. There were specific residues in gyrB for all isolates of species intrinsically resistant to novobiocin. This study provided consensus protein sequences of key elements previously associated with resistance for 25 species of non-aureus staphylococci from dairy cattle. These results will be important for evaluating effects of interventions in antimicrobial use in Canadian dairy herds. PMID:29503642

Prevalence and Genetic Basis of Antimicrobial Resistance in Non-aureus Staphylococci Isolated from Canadian Dairy Herds

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Diego B. Nobrega

2018-02-01

Full Text Available Emergence and spread of antimicrobial resistance is a major concern for the dairy industry worldwide. Objectives were to determine: (1 phenotypic and genotypic prevalence of drug-specific resistance for 25 species of non-aureus staphylococci, and (2 associations between presence of resistance determinants and antimicrobial resistance. Broth micro-dilution was used to determine resistance profiles for 1,702 isolates from 89 dairy herds. Additionally, 405 isolates were sequenced to screen for resistance determinants. Antimicrobial resistance was clearly species-dependent. Resistance to quinupristin/dalfopristin was common in Staphylococcus gallinarum (prevalence of 98%, whereas S. cohnii and S. arlettae were frequently resistant to erythromycin (prevalence of 63 and 100%, respectively. Prevalence of resistance was 10% against β-lactams and tetracyclines. In contrast, resistance to antimicrobials critically important for human medicine, namely vancomycin, fluoroquinolones, linezolid and daptomycin, was uncommon (< 1%. Genes encoding multidrug-resistance efflux pumps and resistance-associated residues in deducted amino acid sequences of the folP gene were the most frequent mechanisms of resistance, regardless of species. The estimated prevalence of the mecA gene was 17% for S. epidermidis. Several genes, including blaZ, mecA, fexA, erm, mphC, msrA, and tet were associated with drug-specific resistance, whereas other elements were not. There were specific residues in gyrB for all isolates of species intrinsically resistant to novobiocin. This study provided consensus protein sequences of key elements previously associated with resistance for 25 species of non-aureus staphylococci from dairy cattle. These results will be important for evaluating effects of interventions in antimicrobial use in Canadian dairy herds.

Supplementary Material for: Detection of antibiotic resistance in probiotics of dietary supplements

KAUST Repository

Wong, Aloysius Tze

2015-01-01

Abstract Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

Similar efficacy and safety of daptomycin versus linezolid for treatment of vancomycin-resistant enterococcal bloodstream infections: a meta-analysis.

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Zhao, Ming; Liang, Liang; Ji, Liwei; Chen, Di; Zhang, Yatong; Zhu, Yuanchao; Patel, Khilna

2016-09-01

Daptomycin and linezolid are the most commonly used antibiotics for bloodstream infection caused by vancomycin-resistant enterococci (VRE-BSI). However, the best therapeutic agent to treat VRE-BSI remains to be established. In order to provide evidence for an optimal treatment decision, a systematic review and meta-analysis was performed comparing the efficacy and safety of daptomycin and linezolid for the treatment of VRE-BSI. After thorough searching of relevant studies from MEDLINE, EMBASE, Clinicaltrials.gov and international meetings up to November 2015, 11 retrospective cohort studies were finally included with a sample size of 1339 patients. Among these 11 included studies, all patients in the daptomycin group received standard or high-dose daptomycin treatment (≥6 mg/kg/day). Data were extracted and pooled risk ratios (RRs) and 95% confidence intervals (95% CIs) were calculated using a random-effects model. The meta-analysis indicated similar crude overall mortality between patients receiving daptomycin and those treated with linezolid (RR = 1.07, 95% CI 0.83-1.37). Moreover, no difference regarding clinical cure (RR = 1.11, 95% CI 0.88-1.42), microbiological cure (RR = 0.99, 95% CI 0.90-1.09) or relapse rate of VRE-BSI (RR = 1.08, 95% CI 0.76-1.52) was found between daptomycin and linezolid. Adverse event rates were not significantly different between the two groups. Currently available evidence indicates similar efficacy and safety of daptomycin and linezolid for the treatment of VRE-BSI. However, the findings in the meta-analysis are limited by heterogeneity between relatively small-scale retrospective studies and should be interpreted cautiously. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

The effects of amoxicillin and vancomycin on parameters reflecting cholesterol metabolism.

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Baumgartner, S; Reijnders, D; Konings, M C J M; Groen, A K; Lütjohann, D; Goossens, G H; Blaak, E E; Plat, J

2017-10-01

Changes in the microbiota composition have been implicated in the development of obesity and type 2 diabetes. However, not much is known on the involvement of gut microbiota in lipid and cholesterol metabolism. In addition, the gut microbiota might also be a potential source of plasma oxyphytosterol and oxycholesterol concentrations (oxidation products of plant sterols and cholesterol). Therefore, the aim of this study was to modulate the gut microbiota by antibiotic therapy to investigate effects on parameters reflecting cholesterol metabolism and oxyphytosterol concentrations. A randomized, double blind, placebo-controlled trial was performed in which 55 obese, pre-diabetic men received oral amoxicillin (broad-spectrum antibiotic), vancomycin (antibiotic directed against Gram-positive bacteria) or placebo (microcrystalline cellulose) capsules for 7days (1500mg/day). Plasma lipid and lipoprotein, non-cholesterol sterol, bile acid and oxy(phyto)sterol concentrations were determined at baseline and after 1-week intervention. Plasma secondary bile acids correlated negatively with cholestanol (marker for cholesterol absorption, r=-0.367; Pcholesterol synthesis, r=0.430; Pcholesterol metabolism, plasma TAG, total cholesterol, LDL-C or HDL-C concentrations as compared to placebo. In addition, both antibiotic treatments did not affect individual isoforms or total plasma oxyphytosterol or oxycholesterol concentrations. Despite strong correlations between plasma bile acid concentrations and cholesterol metabolism (synthesis and absorption), amoxicillin and vancomycin treatment for 7days did not affect plasma lipid and lipoprotein, plasma non-cholesterol sterol and oxy(phyto)sterol concentrations in obese, pre-diabetic men. Copyright © 2017 Elsevier B.V. All rights reserved.

Trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital: a 4-year study Evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos em um hospital terciário brasileiro: um estudo de 4 anos

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Natália Conceição

2011-04-01

Full Text Available INTRODUCTION: In the past two decades members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. This study prospectively analyzed the distribution of species and trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital from 2006-2009. METHODS: Enterococcal species were identified by conventional biochemical tests. The antimicrobial susceptibility profile was performed by disk diffusion in accordance with the Clinical and Laboratory Standards Institute (CLSI. A screening test for vancomycin was also performed. Minimal inhibitory concentration (MIC for vancomycin was determined using the broth dilution method. Molecular assays were used to confirm speciation and genotype of vancomycin-resistant enterococci (VRE. RESULTS: A total of 324 non-repetitive enterococcal isolates were recovered, of which 87% were E. faecalis and 10.8% E. faecium. The incidence of E. faecium per 1,000 admissions increased significantly (p 256µg/ mL and harbored vanA genes. The majority (89.5% of VRE belonged to E. faecium species, which were characteristically resistant to ampicillin and quinolones. Overall, ampicillin resistance rate increased significantly from 2.5% to 21.4% from 2006-2009. Resistance rates for gentamicin, chloramphenicol, tetracycline, and erythromycin significantly decreased over time, although they remained high. Quinolones resistance rates were high and did not change significantly over time. CONCLUSIONS: The data obtained show a significant increasing trend in the incidence of E. faecium resistant to ampicillin and vancomycin.INTRODUÇÃO: Nas últimas duas décadas, os enterococos emergiram como importantes patógenos nosocomiais no mundo inteiro. Neste estudo, foi analisada a distribuição das espécies e a evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos obtidos em um hospital terciário, no período de 2006 a 2009. M�

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolates from Trinidad & Tobago

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Monteil Michele

2006-07-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA has become increasingly prevalent worldwide since it was first reported in a British hospital. The prevalence however, varies markedly in hospitals in the same country, and from one country to another. We therefore sought to document comprehensively the prevalence and antimicrobial susceptibility pattern of MRSA isolates in Trinidad and Tobago. Methods All Staphylococcus aureus isolates encountered in routine clinical specimens received at major hospitals in the country between 2000 and 2001 were identified morphologically and biochemically by standard laboratory procedures including latex agglutination test (Staphaurex Plus; Murex Diagnostics Ltd; Dartford, England; tube coagulase test with rabbit plasma (Becton, Dickinson & Co; Sparks, MD, USA, and DNase test using DNase agar (Oxoid Ltd; Basingstoke, Hampshire, England. MRSA screening was performed using Mueller-Hinton agar containing 6 μg oxacillin and 4% NaCl, latex agglutination test (Denka Seiken Co. Ltd, Tokyo, Japan and E-test system (AB Biodisk, Solna, Sweden. Susceptibility to antimicrobial agents was determined by the modified Kirby Bauer disc diffusion method while methicillin MICs were determined with E-test system. Results Of 1,912 S. aureus isolates received, 12.8% were methicillin (oxacillin resistant. Majority of the isolates were recovered from wound swabs (86.9% and the least in urine (0.4% specimens. Highest number of isolates was encountered in the surgical (62.3% and the least from obstetrics and gynaecology (1.6% facilities respectively. Large proportions of methicillin sensitive isolates are >85% sensitive to commonly used and available antimicrobials in the country. All MRSA isolates were resistant to ceftriaxone, erythromycin, gentamicin and penicillin but were 100% sensitive to vancomycin, rifampin and chloramphenicol. Conclusion There is a progressive increase in MRSA prevalence in the country but

Activity of daptomycin- and vancomycin-loaded poly-epsilon-caprolactone microparticles against mature staphylococcal biofilms

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Santos Ferreira I

2015-07-01

Full Text Available Inês Santos Ferreira,1 Ana F Bettencourt,1 Lídia MD Gonçalves,1 Stefanie Kasper,2 Bertrand Bétrisey,3 Judith Kikhney,2 Annette Moter,2 Andrej Trampuz,4 António J Almeida1 1Research Institute for Medicines (iMed.ULisboa, Faculty of Pharmacy, University of Lisbon, Lisbon, Portugal; 2Biofilmcenter, German Heart Institute Berlin, Berlin, Germany; 3Infectious Diseases Service, Department of Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; 4Center for Musculoskeletal Surgery, Charité – University Medicine Berlin, Berlin, Germany Abstract: The aim of the present study was to develop novel daptomycin-loaded poly-epsilon-caprolactone (PCL microparticles with enhanced antibiofilm activity against mature biofilms of clinically relevant bacteria, methicillin-resistant Staphylococcus aureus (MRSA and polysaccharide intercellular adhesin-positive Staphylococcus epidermidis. Daptomycin was encapsulated into PCL microparticles by a double emulsion-solvent evaporation method. For comparison purposes, formulations containing vancomycin were also prepared. Particle morphology, size distribution, encapsulation efficiency, surface charge, thermal behavior, and in vitro release were assessed. All formulations exhibited a spherical morphology, micro­meter size, and negative surface charge. From a very early time stage, the released concentrations of daptomycin and vancomycin were higher than the minimal inhibitory concentration and continued so up to 72 hours. Daptomycin presented a sustained release profile with increasing concentrations of the drug being released up to 72 hours, whereas the release of vancomycin stabilized at 24 hours. The antibacterial activity of the microparticles was assessed by isothermal microcalorimetry against planktonic and sessile MRSA and S. epidermidis. Regarding planktonic bacteria, daptomycin-loaded PCL microparticles presented the highest antibacterial activity against both strains. Isothermal

Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

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Edmir Geraldo Fraga

2016-09-01

Full Text Available Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

Methicillin-resistant Staphylococcus aureus in North-east Croatia

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Tajana Pastuović

2015-05-01

Full Text Available Objective. The aim of this 5-year study was to determine the frequency and antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA-related infections at Osijek Clinical Hospital. Materials and methods. A total of 1987 staphylococci-infected clinical isolates were collected and analysed at the Microbiology Department of the Public Health Institute of Osijek-Baranja County. Results. Between 2008 and 2012, the average rate of MRSA-related infections in staphylococci-infected patients was 27.4%. The proportion of MRSArelated infections on all Staphylococcus aureus (S. aureus isolates from clinical specimens showed a decreasing trend, from 32.6% in 2008 to 25.5% in 2012. MRSA-related infections were mostly detected in wound swabs (50.6% and aspirates (28.8% of patients hospitalized in the surgical (49.8% and intensive care units (27.9%. MRSA-related infection showed an increase compared to S. aureus-infections in samples of wounds and aspirates in 2011 and 2012 (57.9%/34.9% and 35.2%/16.3%, respectively. The majority of strains of MRSA-related infections were resistant to several antibiotics, including erythromycin and clindamycin, where susceptibility were less than 10%. All MRSA isolates were susceptible to vancomycin, teicoplanin and linezolid. Therefore, antibiotic therapies for MRSA infections include vancomycin, teicoplanin and linezolid, but microbiological diagnostics need to be performed in order to know when the use of glycopeptides and oxazolidinones is indicated. Conclusion. Our results suggest that appropriate prevention measures, combined with the more rational use of antibiotics are crucial to reduce the spread of MRSA-related infection in healthcare settings. Further monitoring is necessary of the incidence and antibiotic susceptibility of MRSA-related infections in our community.

Method of separate determination of high-ohmic sample resistance and contact resistance

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Vadim A. Golubiatnikov

2015-09-01

Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

The need to assay the real MIC when making the decision to eradicate Staphylococcus aureus with vancomycin

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Hanna Tomczak

2013-09-01

Full Text Available Purpose: The aim of the study was a comparison of the MIC (minimal inhibitory concentration evaluated in the automatic system Vitek 2 and the real MIC of vancomycin by the Etest method for S. aureus strains isolated from clinical materials.Material and Methods: Over a twelve-month study period we compared the results obtained with two commercial methods – the automatic system VITEK 2 and the real MIC by Etest – for 359 strains of S. aureus isolated from clinical materials.Results: Most of the strains of S. aureus were cultured from wounds (84, the ear (60 and nose (42. MSSA (methicillin-sensitive Staphylococcus aureus was isolated in 342 cases and MRSA (methicillin-resistant Staphylococcus aureus in 17 cases. The test with the Vitek automatic method showed that vancomycin had MIC values of ≤1.0 μg/ml in more than 96�0and 2.0 μg/ml in over 3�0of cases. Using the Etest technique MIC ≤ 1.0 μg/ml was obtained in only 16.4�0of cases and values of >1.0 μg/ml in 83.6�0of cases.Discussion: In view of such big differences between the MIC values obtained with the two methods the authors suggest that the Etest method of assaying the real MIC is more useful than the automatic method.

Ceftaroline fosamil: a cephalosporin with activity against methicillin-resistant Staphylococcus aureus.

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Poon, Henry; Chang, Mei H; Fung, Horatio B

2012-04-01

Ceftaroline is a cephalosporin with expanded gram-positive activity recently approved for clinical uses by the US Food and Drug Administration. This article provides an overview of the in vitro and in vivo activities, mechanism of action, pharmacologic and pharmacokinetic properties, clinical efficacy, and tolerability of ceftaroline. Relevant information was identified through a search of PubMed (1990-April 2011), EMBASE (1990-April 2011), International Pharmaceutical Abstracts (1970-April 2011), and Google Scholar using the key words ceftaroline, PPI-0903, PPI-0903M, T-91825, and TAK-599. A review of the reference lists of identified articles, a search of the US Food and Drug Administration Web site, and posters and abstracts from scientific meetings yielded additional publications. In vitro, ceftaroline exhibits activity against most aerobic gram-positive isolates, common aerobic gram-negative respiratory pathogens, and some gram-positive anaerobes. The MIC range for most Staphylococcus aureus isolates, including vancomycin-resistant strains was between ≤0.008 and 4 μg/mL. In Phase III studies (CANVAS 1 and CANVAS 2), ceftaroline was found to be noninferior to vancomycin + aztreonam for the treatment of complicated skin and skin-structure infections, with a clinical cure rate of 91.6% among clinically evaluable patients (ceftaroline versus vancomycin + aztreonam: difference, -1.1; 95% CI, -4.2 to 2.0; P = NS). Ceftaroline's efficacy has also been assessed for the treatment of community-acquired pneumonia in 2 Phase III studies (FOCUS 1 and FOCUS 2) and was equivalent to ceftriaxone, with cure rates of 84.3% and 77.7%, respectively, among clinically evaluable patients in the combined analysis (ceftaroline versus ceftriaxone: difference, 6.7; 95% CI, 1.6 to 11.8). The recommended dosage for patients 18 years and older is 600 mg IV every 12 hours. Dosage adjustment is necessary in patients with renal impairment (creatinine clearance ≤50 mL/min). The

Antibiotic-Resistant Enteric Bacteria in Environmental Waters

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Lisa M. Casanova

2016-11-01

Full Text Available Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs, may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne. 100 surface and groundwater sites were sampled for Salmonella, E. coli, and enterococci, and the bacteria isolated from these samples were tested for susceptibility to clinically relevant antibiotics. Salmonella were detected at low levels in some surface but not groundwater. E. coli were in surface waters but not ground in both counties. Enterococci were present in surface water and a small number of groundwater sites. Yersinia was not found. Bacterial densities were similar in both counties. For Salmonella in surface water, the most frequent type of resistance was to sulfamethoxazole. There was no ciprofloxacin resistance. There were a few surface water E. coli isolates resistant to chloramphenicol, gentamicin, and ampicillin. Enterococci in surface water had very low levels of resistance to vancomycin, chloramphenicol, ampicillin, and streptomycin. E. coli and enterococci are present more frequently and at higher levels in surface water than Salmonella, but groundwater contamination with any of these organisms was rare, and low levels of resistance can be found sporadically. Resistant bacteria are relatively uncommon in these eastern N.C. surface and groundwaters, but they could pose a risk of human exposure via ingestion or primary contact recreation.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

The antibiotic resistance "mobilome": searching for the link between environment and clinic.

Science.gov (United States)

Perry, Julie A; Wright, Gerard D

2013-01-01

Antibiotic resistance is an ancient problem, owing to the co-evolution of antibiotic-producing and target organisms in the soil and other environments over millennia. The environmental "resistome" is the collection of all genes that directly or indirectly contribute to antibiotic resistance. Many of these resistance determinants originate in antibiotic-producing organisms (where they serve to mediate self-immunity), while others become resistance determinants only when mobilized and over-expressed in non-native hosts (like plasmid-encoded β-lactamases). The modern environmental resistome is under selective pressure from human activities such as agriculture, which may influence the composition of the local resistome and lead to gene transfer events. Beyond the environment, we are challenged in the clinic by the rise in both frequency and diversity of antibiotic resistant pathogens. We assume that clinical resistance originated in the environment, but few examples of direct gene exchange between the environmental resistome and the clinical resistome have been documented. Strong evidence exists to suggest that clinical aminoglycoside and vancomycin resistance enzymes, the extended-spectrum β-lactamase CTX-M and the quinolone resistance gene qnr have direct links to the environmental resistome. In this review, we highlight recent advances in our understanding of horizontal gene transfer of antibiotic resistance genes from the environment to the clinic. Improvements in sequencing technologies coupled with functional metagenomic studies have revealed previously underappreciated diversity in the environmental resistome, and also established novel genetic links to the clinic. Understanding mechanisms of gene exchange becomes vital in controlling the future dissemination of antibiotic resistance.

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus: A multicentre study.

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Rajaduraipandi K

2006-01-01

Full Text Available Purpose: Methicillin resistant Staphylococcus aureus (MRSA is an important nosocomial pathogen. We report the prevalence and antibiotic susceptibility pattern of MRSA in major southern districts of Tamilnadu. Methods: A total of 7172 clinical specimens and 1725 carrier screening samples were collected from different centers and subjected to MRSA screening using conventional microbiological methods. Subsequently the antibiotic sensitivity test was performed for the confirmed MRSA isolates. Results: Out of 906 strains of S. aureus isolated from clinical and carrier samples, 250 (31.1% and 39 (37.9% were found to be methicillin resistant respectively. Almost all clinical MRSA strains (99.6% were resistant to penicillin, 93.6% to ampicillin, and 63.2% towards gentamicin, co-trimoxazole, cephalexin, erythromycin, and cephotaxime. All MRSA strains (100% of carrier screening samples had resistance to penicillin and about 71.8% and 35.9% were resistant to ampicillin and co-trimoxazole respectively. Multidrug resistance was observed among 63.6% of clinical and 23% of carrier MRSA isolates. However, all strains of clinical and carrier subjects were sensitive to vancomycin. Conclusion: The determination of prevalence and antibiotic sensitivity pattern of MRSA will help the treating clinicians for first line treatment in referral hospitals.

Efficacy of a synthetic antimicrobial peptidomimetic versus vancomycin in a Staphylococcus epidermidis device-related murine peritonitis model

DEFF Research Database (Denmark)

Cavanagh, Jorunn Pauline; Granslo, Hildegunn Norbakken; Fredheim, Elizabeth Aarag

2013-01-01

Objectives Biofilm-forming Staphylococcus epidermidis is a prevalent cause of peritonitis during peritoneal dialysis. We compared the efficacy of a synthetic antimicrobial peptidomimetic (Ltx21) versus vancomycin in a murine model mimicking a device-related peritonitis. Methods Silicone implants......, pre-colonized with an S. epidermidis biofilm, were inserted into the peritoneal cavity of BALB/c mice. Three groups (36 mice in each) with pre-colonized implants received intraperitoneal treatment with Ltx21, vancomycin or placebo. Mice were euthanized on day 3 (n = 12), day 6 (n = 12) or day 8 (n...... = 12) post-implantation. Controls were mice with sterile implants (n = 18) and mice without surgery (n = 6). Bacterial reductions in cfu were analysed from implants and peritoneal fluid (PF). Inflammatory responses in serum and PF were measured. Results Vancomycin resulted in a stronger reduction...

Resistance pattern of clinical isolates of staphylococcus aureus against five groups of antibiotics

International Nuclear Information System (INIS)

Farzana, K.; Hameed, A.

2006-01-01

Among the samples received in pathology laboratory, Pakistan institute of Medical Science, Islamabad, 5069 samples had bacterial growth, among these 2580 (51%) samples were Gram-positive cocci and 1688 were Staphylococcus aureus during a period of two years. Out of these Gram-positive cocci 56% were resistant to penicillin group, 27% were resistant to cephalosporin group, 22% were resistant to aminoglycoside group 15% were resistant to quinolone group and 31% were resistant to other antibiotics (cotrimaxazole, erythromycin, aztreonam, vancomycin, nitrofurantion and meropenam). Antibio-grams of Gram-positive cocci were determined against various antibiotics by disc diffusion method. The rate of resistance to most of the antibiotics such as ampicillin, piperacillin, carbenicillin, penicillin, cephradine, cefotaxime, erythromycin, ceclor, ofloxacin, pefloxacin, ciprofloxacin, cotrimexazole (septran), gentamicin, meropenem, ceftazidime, erythromycin, tobramycin, enoxacin was higher when tested against the isolates collected from pus as compared to those from blood and urine. Antibiotic resistant strains were more prevalent in pus samples than other clinical isolates (blood and urine). The randomly selected 155 strains of Staphylococcus aureus when tested against five groups of antibiotics showed resistance rate against ampicillin (92%), cephradine (92%), cephradine (60%), and gentamicin (58%). However intermediate resistance was found in case of vancomicin (38%), in hospitalized and non-hospitalized patients. (author)

Tabebuia avellanedae naphthoquinones: activity against methicillin-resistant staphylococcal strains, cytotoxic activity and in vivo dermal irritability analysis

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Giambiagi-deMarval Marcia

2006-03-01

Full Text Available Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA and coagulase-negative staphylococcus infections are a worldwide concern. Currently, these isolates have also shown resistance to vancomycin, the last therapy used in these cases. It has been observed that quinones and other related compounds exhibit antibacterial activity. This study evaluated the antibacterial activity, toxicity and in vivo dermal irritability of lapachol extracted from Tabebuia avellanedae and derivatives against methicillin-resistant staphylococcal isolates. In addition, its mechanism of action was also analyzed. Methods The compounds β-lapachone, 3-hydroxy β N lapachone and α-lapachone were tested to determine the MIC values against methicillin-resistant S. aureus, S. epidermidis and S. haemolyticus strains, being the two last ones hetero-resistant to vancomycin. Experiments of protein synthesis analysis to investigate the naphthoquinones action were assessed. In vitro toxicity to eukaryotic BSC-40 African Green Monkey Kidney cell cultures and in vivo primary dermal irritability in healthy rabbits were also performed. Results The compounds tested showed antibacterial activity (MICs of 8, 4/8 and 64/128 μg/mL to β-lapachone, 3-hydroxy β N lapachone and α-lapachone, respectively, but no bactericidal activity was observed (MBC > 512 μg/mL for all compounds. Although it has been observed toxic effect in eukaryotic cells, the compounds were shown to be atoxic when applied as topic preparations in healthy rabbits. No inhibition of proteins synthesis was observed. Conclusion Our results suggest that quinones could be used in topic preparations against wound infections caused by staphylococci, after major investigation of the pharmacological properties of the compounds. Studies about the use of these compounds on tumoral cells could be carried on, due to their effect in eukaryotic cells metabolism.

Cefazolin-Gentamicin versus Vancomycin-Ceftazidime Eye Drops for Bacterial Corneal Ulcers; a Randomized Clinical Trial

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Ali-Reza Dehghani

2009-01-01

Full Text Available

PURPOSE: To compare the efficacy of topical cefazolin-gentamicin versus vancomycin-ceftazidime for treatment of bacterial corneal ulcers. METHODS: This randomized double-masked clinical trial was performed on consecutive patients with bacterial corneal ulcers referred to Feiz Hospital, Isfahan, Iran from 2004 to 2005. Patients were randomly assigned to cefazolin-gentamicin or vancomycin-ceftazidime eye drops in a masked fashion. Outcome measures included time for resolution of stromal infiltration, re-epithelization of the epithelial defect, and clearance of anterior chamber inflammation as well as culture results and complications. RESULTS: The study included 89 eyes of 89 patients with bacterial corneal ulcers consisting of 57 (64% male and 32 (36% female subjects. Specimens were culture-negative in 46% of cases. Forty-one eyes received cefazolin-gentamicin and 48 eyes were treated with vancomycin-ceftazidime. Time for resolution of stromal infiltration was 17.7±4.3 days versus 13.8±3.6 days (P=0.04, time to complete re-epithelization was 13.2±3.1 days versus 9.6±2.7 days (P=0.01 and time for clearing of the anterior chamber was 11.6±2.9 days versus 8.1±2.3 days (P

Antimicrobial Resistance of Staphylococcal Strains Isolated from Various Pathological Products

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Laura-Mihaela SIMON

2010-12-01

Full Text Available Background: The optimal choice of antimicrobial therapy is an important problem in hospital environment in which the selection of resistant and virulent strains easy occurs. S. aureus and especially MRSA(methicillin-resistant S. aureus creates difficulties in both treatment and prevention of nosocomial infections. Aim: The purpose of this study is to determine the sensitivity and the resistance to chemotherapy of staphylococci strains isolated from various pathological products. Material and Method: We identified Staphylococccus species after morphological appearance, culture properties, the production of coagulase, hemolisines and the enzyme activity. The susceptibility tests were performed on Mueller-Hinton medium according to CLSI (Clinical and Laboratory Standards Institute. Results: The strains were: MSSA (methicillin-susceptible S. aureus (74%, MRSA (8%, MLS B (macrolides, lincosamides and type B streptogramines resistance (12% and MRSA and MLS B (6%. MRSA strains were more frequently isolated from sputum. MRSA associated with the MLS B strains were more frequently isolated from pus. MLS B strains were more frequently isolated from sputum and throat secretions. All S. aureus strains were susceptible to vancomycin and teicoplanin. Conclusions: All staphylococcal infections require resistance testing before treatment. MLS B shows a high prevalence among strains of S. aureus. The association between MLS B and MRSA remains a major problem in Romania.

Use of 8.4% Sodium Bicarbonate in Buffering Commonly Administered Vancomycin Hydrochloride Solutions for Use with Midline or Peripheral Line Catheters.

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Puertos, Enrique; Spencer, Melissa

2015-01-01

The primary objective of this study was to evaluate the use of 8.4% sodium bicarbonate in the buffering of commonly administered vancomycin hydrochloride solutions for use with midline or peripheral line catheters. Nine admixtures of vancomycin hydrochloride were aseptically prepared for this study. Vancomycin hydrochloride solutions were prepared in triplicates in the following strengths, 1 gram, 2 grams, and 3 grams, which were added to 250-mL bags of sodium chloride 0.9% injection (with overfill). To each prepared solution of vancomycin hydrochloride, 0.5 mL of 8.4% sodium bicarbonate was added. The pH was measured to obtain a baseline level. At day 9, the pH of each sample was measured and compared to those at baseline. The osmolality of each sample was also measured. There was no statistical difference in the pH at baseline and at day 9 (α = 0.05, P = 0.347). A solution of vancomycin hydrochloride that is compounded in 250 mL of sodium chloride 0.9% injection (including overfill) and buffered with 0.5 mL of 8.4% sodium bicarbonate maintained a pH in the range of 5 to 9 and an osmolality in the range of 150 mOsm/kg to 500 mOsm/kg.

Antimicrobial resistance profile of Enterococcus spp isolated from food in Southern Brazil

Science.gov (United States)

Riboldi, Gustavo Pelicioli; Frazzon, Jeverson; d’Azevedo, Pedro Alves; Frazzon, Ana Paula Guedes

2009-01-01

Fifty-six Enterococcus spp. strains were isolated from foods in Southern Brazil, confirmed by PCR and classified as Enterococcus faecalis (27), Enterococcus faecium (23) and Enterococcus spp (6). Antimicrobial susceptibility tests showed resistance phenotypes to a range of antibiotics widely administrated in humans such as gentamycin, streptomycin, ampicillin and vancomycin. PMID:24031330

Bacillus coagulans GBI-30, 6086 limits the recurrence of Clostridium difficile-Induced colitis following vancomycin withdrawal in mice

OpenAIRE

Fitzpatrick, Leo R; Small, Jeffrey S; Greene, Wallace H; Karpa, Kelly D; Farmer, Sean; Keller, David

2012-01-01

Abstract Background Recently, we found that the probiotic strain Bacillus coagulans GBI-30, 6086 (GanedenBC30) improved indices of Clostridium difficile (C. difficile)-induced colitis in mice (Fitzpatrick et al., Gut Pathogens, 2011). Our goal was to determine if BC30 could also prevent the recurrence of C. difficile-induced colitis in mice, following initial treatment with vancomycin. During study days 0 through 5, mice were treated with antibiotics. On day 6, the C. difficile strain VPI 104...

The Antibiotic Resistance ‘Mobilome’: searching for the link between environment and clinic.

Directory of Open Access Journals (Sweden)

Julie ePerry

2013-05-01

Full Text Available Antibiotic resistance is an ancient problem, owing to the co-evolution of antibiotic-producing and target organisms in the soil and other environments over millennia. The environmental ‘resistome’ is the collection of all genes that directly or indirectly contribute to antibiotic resistance. Many of these resistance determinants originate in antibiotic-producing organisms (where they serve to mediate self-immunity, while others become resistance determinants only when mobilized and over-expressed in non-native hosts (like plasmid-based β-lactamases. The modern environmental resistome is under selective pressure from human activities such as agriculture, which may influence the composition of the local resistome and lead to gene transfer events. Beyond the environment, we are challenged in the clinic by the rise in both frequency and diversity of antibiotic resistant pathogens. We assume that clinical resistance originated in the environment, but few examples of direct gene exchange between the environmental resistome and the clinical resistome have been documented. Strong evidence exists to suggest that clinical aminoglycoside and vancomycin resistance enzymes, the extended-spectrum β-lactamase CTX-M and the quinolone resistance gene Qnr have direct links to the environmental resistome. In this review, we highlight recent advances in our understanding of horizontal gene transfer of antibiotic resistance genes from the environment to the clinic. Improvements in sequencing technologies coupled with functional metagenomic studies have revealed previously underappreciated diversity in the environmental resistome, and also established novel genetic links to the clinic. Understanding mechanisms of gene exchange becomes vital in controlling the future dissemination of antibiotic resistance.