scholarly journals Low Prevalence of Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Isolates among Connecticut Veterans

2011 ◽  
Vol 56 (1) ◽  
pp. 582-583 ◽  
Author(s):  
Susan L. Fink ◽  
Richard A. Martinello ◽  
Sheldon M. Campbell ◽  
Thomas S. Murray
Keyword(s):  
Staphylococcus Aureus ◽  
Population Analysis ◽  
Area Under The Curve ◽  
Curve Analysis ◽  
Routine Screening ◽  
Glycopeptide Resistance ◽  
Methicillin Resistant ◽  
Content Type ◽  
Low Prevalence ◽  
Profile Area

ABSTRACTThe Etest glycopeptide resistance detection identified two potential heterogeneous vancomycin-intermediateStaphylococcus aureus(hVISA) isolates from a screen of 288 methicillin-resistantStaphylococcus aureus(MRSA) isolates from patients at a Connecticut Veterans Hospital. However, the two isolates did not meet the criteria for hVISA by the population analysis profile-area under the curve analysis, arguing against routine screening for hVISA in this low prevalence population.

scholarly journals Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation

2015 ◽  
Vol 53 (11) ◽  
pp. 3543-3546 ◽  
Author(s):  
Riad Khatib ◽  
Kathleen Riederer ◽  
Mamta Sharma ◽  
Stephen Shemes ◽  
Sugantha P. Iyer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Standard ◽  
Population Analysis ◽  
Area Under The Curve ◽  
Brain Heart Infusion ◽  
Roc Curves ◽  
Clinical Samples ◽  
Content Type ◽  
Interpretation Criteria ◽  
Profile Area

BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptibleStaphylococcus aureus(VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistantStaphylococcus aureus(MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptibleS. aureus(MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation.

scholarly journals Pneumonia Caused by Methicillin-Resistant Staphylococcus aureus: Does Vancomycin Heteroresistance Matter?

2016 ◽  
Vol 60 (3) ◽  
pp. 1708-1716 ◽  
Author(s):  
Kimberly C. Claeys ◽  
Abdalhamid M. Lagnf ◽  
Jessica A. Hallesy ◽  
Matthew T. Compton ◽  
Alison L. Gravelin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Outcomes ◽  
Population Analysis ◽  
Univariate Analysis ◽  
Area Under The Curve ◽  
Multivariable Logistic Regression Analysis ◽  
High Morbidity ◽  
Inpatient Mortality ◽  
Methicillin Resistant ◽  
Content Type

Vancomycin remains the mainstay treatment for methicillin-resistantStaphylococcus aureus(MRSA) infections, including pneumonia. There is concern regarding the emergence of vancomycin tolerance, caused by heterogeneous vancomycin-intermediateS. aureus(hVISA), and subsequent vancomycin treatment failure. Pneumonia is associated with high morbidity and mortality, especially with delays in appropriate therapy. This study evaluated the clinical outcomes of patients with hVISA pneumonia compared to those with vancomycin-susceptibleS. aureus(VSSA) pneumonia. A retrospective cohort of patients with MRSA pneumonia from 2005 to 2014 was matched at a ratio of 2:1 VSSA to hVISA infections to compare patient characteristics, treatments, and outcomes. hVISA was determined by the 48-h population analysis profile area under the curve. Characteristics between VSSA and hVISA infections were compared by univariate analysis and multivariable logistic regression analysis to determine independent risk factors of inpatient mortality. Eighty-seven patients were included, representing 29 hVISA and 58 VSSA cases of pneumonia. There were no significant differences in demographics or baseline characteristics. Sequential organ failure assessment (SOFA) scores were a median of 7 (interquartile ratio [IQR], 5 to 8) in hVISA patients and 5 (IQR, 3 to 8) in VSSA (P= 0.092) patients. Inpatient mortality was significantly higher in hVISA patients (44.8% versus 24.1%;P= 0.049). Predictors of inpatient mortality upon multivariable regression were SOFA score (adjusted odds ratio [aOR], 1.36; 95% confidence interval [CI], 1.08 to 1.70), Panton-Valentine leukocidin (PVL) positivity (aOR, 6.63; 95% CI, 1.79 to 24.64), and hVISA phenotype (aOR, 3.95; 95% CI, 1.18 to 13.21). Patients with hVISA pneumonia experienced significantly higher inpatient mortality than those with VSSA pneumonia. There is a need to consider the presence of vancomycin heteroresistance in pneumonia caused by MRSA in order to potentially improve clinical outcomes.

scholarly journals Screening and detection of heterogenous vancomycin intermediate Staphylococcus aureus in Hospital Kuala Lumpur Malaysia, using the glycopeptide resistance detection etest and population analysis profiling

2012 ◽  
Vol 4 (1) ◽  
pp. 20 ◽  
Author(s):  
Siti Roszilawati Ramli ◽  
Hui-min Neoh ◽  
Muhammad Nazri Aziz ◽  
Salasawati Hussin
Keyword(s):  
Staphylococcus Aureus ◽  
Prevalence Rate ◽  
Population Analysis ◽  
Kuala Lumpur ◽  
Glycopeptide Resistance ◽  
Methicillin Resistant ◽  
First Report ◽  
Resistance Detection

In a 3-month study done in Hospital Kuala Lumpur (HKL), 7 out of 320 methicillin resistant <em>Staphylococcus aureus </em>isolates were confirmed as heterogeneous vancomycin intermediate S. aureus (hVISA) using the glycopeptide resistance detection e-test and population analysis, giving a prevalence rate of 2.19%. This is the first report of hVISA in Malaysia.

scholarly journals Differentiation of Community-Associated and Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates and Identification of spa Types by Use of PCR and High-Resolution Melt Curve Analysis

2020 ◽  
Vol 58 (5) ◽  
Author(s):  
Seyed A. Ghorashi ◽  
Jane Heller ◽  
Quincy Zhang ◽  
Shafi Sahibzada
Keyword(s):  
Staphylococcus Aureus ◽  
High Resolution ◽  
Curve Analysis ◽  
Health Concern ◽  
Staphylococcal Protein A ◽  
Visual Interpretation ◽  
High Resolution Melt ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Strains

ABSTRACT Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are present worldwide and represent a major public health concern. The capability of PCR followed by high-resolution melt (HRM) curve analysis for the detection of community-associated and livestock-associated MRSA strains and the identification of staphylococcal protein A (spa) locus was evaluated in 74 MRSA samples which were isolated from the environment, humans, and pigs on a single piggery. PCR-HRM curve analysis identified four spa types among MRSA samples and differentiated MRSA strains accordingly. A nonsubjective differentiation model was developed according to genetic confidence percentage values produced by tested samples, which did not require visual interpretation of HRM curve results. The test was carried out at different settings, and result data were reanalyzed and confirmed with DNA sequencing. PCR-HRM curve analysis proved to be a robust and reliable test for spa typing and can be used as a tool in epidemiological studies.

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

2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Ximena Castañeda ◽  
Cristina García-de-la-Mària ◽  
Oriol Gasch ◽  
Juan M. Pericas ◽  
Yolanda Armero ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Good Predictor ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Area Under The Curve ◽  
Methicillin Resistant ◽  
Bacterial Counts ◽  
Content Type ◽  
Treatment Groups ◽  
Mrsa Strains

ABSTRACT 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 log10 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.

scholarly journals Scope and Predictive Genetic/Phenotypic Signatures of Bicarbonate (NaHCO3) Responsiveness and β-Lactam Sensitization in Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Selvi C. Ersoy ◽  
Mariam Otmishi ◽  
Vanessa T. Milan ◽  
Liang Li ◽  
Youngju Pak ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Population Analysis ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mueller Hinton ◽  
Testing Medium ◽  
Mrsa Strains ◽  
Mueller Hinton Broth

ABSTRACT Addition of sodium bicarbonate (NaHCO3) to standard antimicrobial susceptibility testing medium reveals certain methicillin-resistant Staphylococcus aureus (MRSA) strains to be highly susceptible to β-lactams. We investigated the prevalence of this phenotype (NaHCO3 responsiveness) to two β-lactams among 58 clinical MRSA bloodstream isolates. Of note, ∼75% and ∼36% of isolates displayed the NaHCO3 responsiveness phenotype to cefazolin (CFZ) and oxacillin (OXA), respectively. Neither intrinsic β-lactam MICs in standard Mueller-Hinton broth (MHB) nor population analysis profiles were predictive of this phenotype. Several genotypic markers (clonal complex 8 [CC8]; agr I and spa t008) were associated with NaHCO3 responsiveness for OXA.

scholarly journals Performance of vancomycin and teicoplanin disk diffusion test in isogenic vancomycin non-susceptible Staphylococcus aureus

2015 ◽  
Vol 9 (02) ◽  
pp. 157-164 ◽  
Author(s):  
Sujintana Wongthong ◽  
Karnjana Dutchanutouch ◽  
Viladda Namsaengkang ◽  
Aroonwadee Chanawong ◽  
Chotechana Wilailuckana ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Predictive Value ◽  
Population Analysis ◽  
Area Under The Curve ◽  
Serial Passage ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Methicillin Resistant

Introduction: Detection of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) is currently problematic. Although the population analysis profile with area under the curve (PAP-AUC) is the gold standard for detecting hVISA strains, this method is time consuming. This study aimed to induce vancomycin non-susceptible Staphylococcus aureus isolates in methicillin-resistant S. aureus (MRSA) and to determine the performance of the vancomycin and teicoplanin disk diffusion test for screening of induced and natural vancomycin non-susceptible isolates. Methodology: Vancomycin resistance was induced in vitro in methicillin-resistant S. aureus by serial passage in media with increasing vancomycin concentrations. All test isolates were confirmed for their susceptibility to vancomycin by using a PAP-AUC method. The performance of the vancomycin and teicoplanin disk diffusion test for detecting both induced and natural hVISA/VISA isolates was analyzed using the MedCal program version 10.2.0. Results: The induction test revealed that 42 of 78 MRSA isolates (53.8%) became hVISA and/or VISA. Using 10, 15, 20, 30 µg vancomycin disks and a 30 µg teicoplanin disk, the highest performance (88.9%) for hVISA/VISA detection (71.1%, sensitivity, 100% specificity, 100% positive predictive value, and 75% negative predictive value) was obtained when a 20 µg vancomycin disk was used at 1.0 McFarland inoculum for a 24-hour incubation. Conclusions: The results indicated that using a 20 µg vancomycin disk and bacterial inoculum of 1.0 McFarland is simple to perform and provides a primary result for hVISA/VISA screening within 24 hours.

scholarly journals Screening and Detection of Heterogenous Vancomycin Intermediate Staphylococcus aureus in Hospital Kuala Lumpur Malaysia, Using the Glycopeptide Resistance Detection Etest and Population Analysis Profiling

2012 ◽  
Vol 4 (1) ◽  
pp. 71-72
Author(s):  
Siti Roszilawati Ramli ◽  
Hui-min Neoh ◽  
Muhammad Nazri Aziz ◽  
Salasawati Hussin
Keyword(s):  
Staphylococcus Aureus ◽  
Prevalence Rate ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Population Analysis ◽  
Kuala Lumpur ◽  
Glycopeptide Resistance ◽  
Methicillin Resistant ◽  
First Report ◽  
Resistance Detection

In a 3-month study done in Hospital Kuala Lumpur (HKL), 7 out of 320 methicillin resistant Staphylococcus aureus isolates were confirmed as heterogeneous vancomycin intermediate S. aureus (hVISA) using the glycopeptide resistance detection e-test and population analysis, giving a prevalence rate of 2.19%. This is the first report of hVISA in Malaysia.

scholarly journals The Role of ArlRS and VraSR in Regulating Ceftaroline Hypersusceptibility in Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 821
Author(s):  
Maite Villanueva ◽  
Melanie Roch ◽  
Iñigo Lasa ◽  
Adriana Renzoni ◽  
William L. Kelley
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Control Strategies ◽  
Population Analysis ◽  
Methicillin Resistant ◽  
Signal Systems ◽  
Fifth Generation ◽  
Sensing Systems ◽  
Two Component ◽  
Two Component Systems

Methicillin-resistant Staphylococcus aureus infections are a global health problem. New control strategies, including fifth-generation cephalosporins such as ceftaroline, have been developed, however rare sporadic resistance has been reported. Our study aimed to determine whether disruption of two-component environmental signal systems detectably led to enhanced susceptibility to ceftaroline in S. aureus CA-MRSA strain MW2 at sub-MIC concentrations where cells normally continue to grow. A collection of sequential mutants in all fifteen S. aureus non-essential two-component systems (TCS) was first screened for ceftaroline sub-MIC susceptibility, using the spot population analysis profile method. We discovered a role for both ArlRS and VraSR TCS as determinants responsible for MW2 survival in the presence of sub-MIC ceftaroline. Subsequent analysis showed that dual disruption of both arlRS and vraSR resulted in a very strong ceftaroline hypersensitivity phenotype. Genetic complementation analysis confirmed these results and further revealed that arlRS and vraSR likely regulate some common pathway(s) yet to be determined. Our study shows that S. aureus uses particular TCS environmental sensing systems for this type of defense and illustrates the proof of principle that if these TCS were inhibited, the efficacy of certain antibiotics might be considerably enhanced.

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