scholarly journals Prevalence and Characterization of Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Isolates from 14 Cities in China

2009 ◽  
Vol 53 (9) ◽  
pp. 3642-3649 ◽  
Author(s):  
Wenjia Sun ◽  
Hongbin Chen ◽  
Yudong Liu ◽  
Chunjiang Zhao ◽  
Wright W. Nichols ◽  
...  

ABSTRACT The prevalence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) among 1,012 vancomycin-susceptible methicillin (meticillin)-resistant S. aureus isolates collected from 14 cities in China from 2005 to 2007 was 13 to 16%, as determined by a combination of (i) measurement by the modified population analysis profile-area under the curve method (PAP-AUC) and (ii) estimation from the measured sensitivity and specificity of a screening method. Two hundred isolates from blood were chosen as a subset for measurement of the sensitivities and the specificities of several previously described screening methods by using the results of PAP-AUC as the reference. During this testing, one isolate was found to be a vancomycin-intermediate S. aureus (VISA) strain so was not used in the evaluation of the screening tests. Of the other 199 isolates, 26 (13.1%) were hVISA, as assessed by PAP-AUC. A screening cascade of culturing the isolates on brain heart infusion agar containing teicoplanin (5 mg/liter) and then subjecting the positive isolates to a macro-Etest method was applied to the 812 non-blood isolates, yielding 149 positive results. From these results and by adjusting for sensitivity (0.423) and specificity (0.861), the prevalence was estimated to be 15.7%. The precision of that estimate was assessed by reapplying the screening cascade to 120 randomly selected isolates from the 812 non-blood isolates and simultaneously determining their heterogeneous vancomycin-intermediate susceptibility status by PAP-AUC. Because PAP-AUC is impractical for use with large numbers of isolates, the screening-based estimation method is useful as a first approximation of the prevalence of hVISA. Of the 27 VISA or hVISA isolates from blood, 22.2% and 74.1% were staphylococcal chromosome cassette mec types II and III, respectively, while 77.8% and 22.2% were agr type 1 and agr type 2, respectively; the MIC ranges were 0.5 to 4 mg/liter for vancomycin and 0.25 to 1 mg/liter for daptomycin.

2015 ◽  
Vol 53 (11) ◽  
pp. 3543-3546 ◽  
Author(s):  
Riad Khatib ◽  
Kathleen Riederer ◽  
Mamta Sharma ◽  
Stephen Shemes ◽  
Sugantha P. Iyer ◽  
...  

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.


Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 729 ◽  
Author(s):  
Andreas Chrysostomou ◽  
Dora Stylianou ◽  
Anastasia Constantinidou ◽  
Leondios Kostrikis

Cervical cancer is the fourth most frequently occurring cancer in women around the world and can affect them during their reproductive years. Since the development of the Papanicolaou (Pap) test, screening has been essential in identifying cervical cancer at a treatable stage. With the identification of the human papillomavirus (HPV) as the causative agent of essentially all cervical cancer cases, HPV molecular screening tests and HPV vaccines for primary prevention against the virus have been developed. Accordingly, comparative studies were designed to assess the performance of cervical cancer screening methods in order to devise the best screening strategy possible. This review critically assesses the current cervical cancer screening methods as well as the implementation of HPV vaccination in Europe. The most recent European Guidelines and recommendations for organized population-based programs with HPV testing as the primary screening method are also presented. Lastly, the current landscape of cervical cancer screening programs is assessed for both European Union member states and some associated countries, in regard to the transition towards population-based screening programs with primary HPV testing.


2008 ◽  
Vol 52 (12) ◽  
pp. 4510-4513 ◽  
Author(s):  
Klaudia Kosowska-Shick ◽  
Lois M. Ednie ◽  
Pamela McGhee ◽  
Kathy Smith ◽  
Cynthia D. Todd ◽  
...  

ABSTRACT All 982 methicillin-resistant Staphylococcus aureus strains collected from August 2006 to December 2007 were tested for vancomycin susceptibility by using 3-μg/ml vancomycin brain heart infusion screening plates, a vancomycin Etest, and a vancomycin/teicoplanin macro Etest. Three vancomycin-intermediate Staphylococcus aureus (VISA) (0.3%) and two heterogeneous VISA (0.2%) isolates were identified. The screening method yielded 895 cases of ≤1 colony and 87 positive results (with growth of >1 colony after 48 h); further Etests showed 82/87 isolates with growth on screening plates to be false positive. Repeat testing showed a false-positivity rate of only 15 of the original 87 isolates by plate screening.


2009 ◽  
Vol 53 (8) ◽  
pp. 3447-3452 ◽  
Author(s):  
K. C. Horne ◽  
B. P. Howden ◽  
E. A. Grabsch ◽  
M. Graham ◽  
P. B. Ward ◽  
...  

ABSTRACT Although methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains with reduced susceptibility to vancomycin (RVS-MRSA; including vancomycin-intermediate S. aureus [VISA] and heterogeneous VISA [hVISA]) have been linked with vancomycin treatment failure, it is unclear whether they are more pathogenic than vancomycin-susceptible MRSA (VS-MRSA). We prospectively assessed patients with clinical MRSA isolates during a 10-month period to determine clinical status (infection versus colonization) and therapeutic outcome before correlating these findings with the results of detailed in vitro assessment of vancomycin susceptibility, including population analysis profile (PAP) testing. hVISA and VISA were defined by standard PAP criteria (area-under-the-curve ratio compared to that of the reference hVISA strain Mu3 [≥0.9]) and routine CLSI criteria (vancomycin MIC, 4 to 8 μg/ml), respectively. Among the 117 patients assessed, 58 had RVS-MRSA isolates (56 hVISA and 2 VISA) and 59 had VS-MRSA isolates; the patient demographics and comorbidities were similar. RVS-MRSA was associated with a lower rate of infection than VS-MRSA (29/58 versus 46/59; P = 0.003), including a lower rate of bacteremia (3/58 versus 20/59, respectively; P < 0.001). The cure rates in RVS-MRSA and VS-MRSA groups were not statistically different (16/26 versus 31/42; P = 0.43), but the post hoc assessment of treatment regimes and study size made detailed conclusions difficult. The results of the macro method Etest correlated well with the PAP results (sensitivity, 98.3%, and specificity, 91.5%), but broth microdilution and our preliminary RVS-MRSA detection method correlated poorly. All isolates were susceptible to linezolid and daptomycin. These data suggest that detailed prospective laboratory identification of RVS-MRSA isolates may be of limited value and that, instead, such in vitro investigation should be reserved for isolates from patients who are failing appropriate anti-MRSA therapy.


2018 ◽  
Vol 77 (1) ◽  
Author(s):  
Ingrid T. Metsing ◽  
Wanda Jacobs ◽  
Rekha Hansraj

Background: What constitutes an appropriate vision screening protocol is controversial, because the tests or methods are expected to be cost-effective, expedient and easy but efficient in detecting visual anomalies among children.Aim: This review intends to compare the different vision screening tests for children and methods in the interest of identifying the most effective screening method from the standpoint of validity, public acceptance, expediency and cost.Method: The literature search was performed for this review using the Medline, Science Direct and EBSCOhost databases. The search terms used were vision screening methods or tests, children’s vision screenings, computer software programs and vision screening instruments. The inclusion criteria for the articles reviewed were all types of articles related to vision screening methods. The exclusion criteria were all articles for which full text was not available and those not available in English. Eighty articles were analysed, of which 33 were found to have complied with the inclusion criteria and were selected. From the first round of articles retrieved, additional references were identified by a manual search among the cited references.Results: Evidence from the literature reviewed demonstrated that the conventional vision screening method (isolated and combination tests) is the method commonly used to detect a range of relevant visual anomalies among the schoolgoing age group (≥ 6 years) and drew attention to the need for training of vision screening personnel. However, in addition to the conventional method, other vision screening methods include instruments as an adjunct for screening preschoolers and those difficult to screen (≤ 6 years).Conclusion: Inconsistencies in what constitutes an appropriate vision screening method still exist, especially with the booming market of using computer software programs, which still needs to be validated.


Author(s):  
Rohini N. S. ◽  
Ravishankar S. N. ◽  
Kala K. ◽  
Rakshith N. R.

Background: Asymptomatic bacteriuria (ASB) in pregnancy is a significant risk factor for developing upper urinary tract infection and pyelonephritis which is associated with significant maternal and fetal risks. The aim of this study was to know the prevalence of asymptomatic bacteriuria in pregnancy, to identify the organisms and their antibiotic susceptibility patterns and to formulate a single or combined rapid screening method as an acceptable alternative to urine culture.Methods: A total of 375 pregnant women aged between 18 to 45 years were included in this study. Clean catch mid-stream urine samples were collected. Screening tests done were gram staining of uncentrifuged urine, pus cell count, nitrite test and leukocyte esterase test. Identification of pathogens and antibiotic sensitivity tests were performed as per standard urine culture and sensitivity methods.Results: Out of the 375 pregnant women, 31 (8.4%) had significant bacteriuria. High percentage of women with ASB were primigravidas (51.38%) and in 2nd trimester (43.86%). The most common organism isolated was E.coli (56.14%). In screening tests, gram staining of uncentrifuged urine had a sensitivity of 85.71%. Sensitivity of 71.42% was found in Nitrite and leucocyte esterase tests. However, the combination of these two tests, with either test positive, showed sensitivity and negative predictive value of 90.47% and 99.09% respectively.Conclusions: Early detection and treatment of ASB in pregnancy can prevent complications. ASB can be identified by simple and combined rapid screening methods and urine culture along with antibiogram. Therefore, screening and treatment of ASB may be incorporated as routine antenatal care for safe motherhood and healthy newborn.


1970 ◽  
Vol 16 (2) ◽  
pp. 91-94 ◽  
Author(s):  
Joseph T. Parisi ◽  
Michael P. Kiley

Large numbers of chromogenic variants were isolated from cultures of a parent strain of Staphylococcus aureus growing in the dialysate but not in the residue of brain heart infusion (Difco). Gas–liquid chromatographic analysis of the dialysate detected 18 amino acids in this medium. Large numbers of chromogenic variants also were isolated from 13 of 18 synthetic media deficient in a single amino acid but not in the complete synthetic medium containing all 18 amino acids. Gas–liquid chromatographic analysis detected marked quantitative differences in the amino acid metabolites present in a complete synthetic medium and the synthetic medium deficient in arginine after growth for 12 days. The data suggest that differences in the amino acid metabolism of the parent and chromogenic variants could account for the population changes observed in brain heart infusion.


2014 ◽  
Vol 58 (6) ◽  
pp. 3133-3136 ◽  
Author(s):  
Stephanie N. Saravolatz ◽  
Hayley Martin ◽  
Joan Pawlak ◽  
Leonard B. Johnson ◽  
Louis D. Saravolatz

ABSTRACTHeteroresistance refers to the presence, within a large population of antimicrobial-susceptible microorganisms, of subpopulations with lesser susceptibilities. Ceftaroline is a novel cephalosporin with activity against methicillin-resistantStaphylococcus aureus(MRSA). The aim of this study was to detect the prevalence of ceftaroline heteroresistancein vitroin a select group ofS. aureusstrains. There were 57 isolates selected for evaluation, 20 MRSA, 20 vancomycin-intermediateS. aureus(VISA), 7 daptomycin-nonsusceptibleS. aureus(DNSSA), 6 linezolid-nonsusceptibleS. aureus(LNSSA), and 4 heteroresistant VISA (hVISA) isolates. MICs and minimal bactericidal concentrations were determined using the broth microdilution method according to CLSI guidelines. All of the isolates were analyzed by pulsed-field gel electrophoresis. The staphylococcal cassette chromosomemecelement (SCCmec) types were determined by a multiplex PCR. Population analysis profiles (PAPs) were performed to determine heteroresistance for all of the isolates using plates made by adding various amounts of ceftaroline to brain heart infusion agar. The frequencies of resistant subpopulations were 1 in 104to 105organisms. We determined that 12 of the 57 (21%) isolates tested were ceftaroline-heteroresistantS. aureus(CHSA). CHSA occurred among strains with reduced susceptibilities to vancomycin, daptomycin, and linezolid but occurred in none of the USA-300 isolates tested. Evaluation of the heteroresistant strains demonstrated that the phenotype was unstable. Further studies are needed to determine whether CHSA has a role in clinical failures and to determine the implications of our study findings.


2013 ◽  
Vol 58 (2) ◽  
pp. 740-745 ◽  
Author(s):  
Sandra S. Richter ◽  
Daniel J. Diekema ◽  
Kristopher P. Heilmann ◽  
Cassie L. Dohrn ◽  
Emily K. Crispell ◽  
...  

ABSTRACTForty-two medical centers from throughout the United States participating in a longitudinal surveillance program were asked to submit 100 consecutiveStaphylococcus aureusisolates during July to December 2011. Susceptibility testing using CLSI broth microdilution andmecAdetection by PCR analysis was performed on the 4,131 isolates collected. Methods employing Etest glycopeptide resistance detection (GRD; bioMérieux) and brain heart infusion agar containing 4 μg/ml vancomycin (BHIV) were used to screen methicillin-resistantS. aureus(MRSA) isolates for heterogeneous intermediate-level resistance to vancomycin (hVISA). Isolates with positive hVISA screen results were confirmed by population analysis profiling-area under the curve (PAP-AUC) determinations. The genetic relatedness of hVISA, ceftaroline-nonsusceptible, or high-level (HL) mupirocin resistance MRSA isolates was assessed by pulsed-field gel electrophoresis (PFGE). Among 2,093 MRSA isolates, the hVISA screen results were positive with 47 isolates by Etest GRD and 30 isolates by BHIV agar screen. Twenty-five of the GRD- or BHIV screen-positive isolates were confirmed as hVISA by PAP-AUC testing. Results of the current study were compared to results obtained from prior surveillance performed in 2009. The prevalence of hVISA among MRSA isolates was higher in 2011 than in 2009 (1.2% versus 0.4%,P= 0.003), especially for isolates with a vancomycin MIC of 2 (45.4% versus 14.3%,P= 0.01). The overall rate of ceftaroline susceptibility in the current study was 99.4% (one hVISA isolate had an intermediate ceftaroline MIC). HL mupirocin resistance increased from 2.2% in 2009 to 3.2% in 2011 (P= 0.006). Although overall rates of hVISA and HL mupirocin resistance are low, they have increased since 2009.


2010 ◽  
Vol 4 (1) ◽  
pp. 141-145
Author(s):  
Montri Pongkumpai ◽  
Suwanna Trakulsomboon ◽  
Chusana Suankratay

Abstract Background: Staphylococcus aureus with reduced susceptibility to vancomycin or heterogeneous vancomycinintermediate S. aureus (hVISA) have become increasingly reported from various parts of the world. hVISA cannot be detected by routine test for minimal inhibitory concentration (MIC) for vancomycin. The gold standard method for detection, population analysis profiles (PAP) method, is complicated, time-consuming, expensive, and needs well-trained microbiologists. Objective: Evaluate of 2.0 McFarland Etest method, in comparison with the PAP method, for detection of hVISA in clinical specimens. Methods: All methicillin-resistant S. aureus strains from clinical specimens isolated from consecutive patients attended at King Chulalongkorn Memorial Hospital and Siriraj Hospital, Bangkok between 2006 and 2007 were studied. 1 hundred nineteen specimens were obtained. The PAP method detected six hVISA strains 5 from blood and from cultures) from four patients at King Chulalongkorn Memorial Hospital, accounting for a prevalence of 6.35%. The MIC determined by agar dilution method was in the range of 2-3 μg/mL. Results: 2.0 McFarland Etest method detected no false positive and five false negatives (42%), and gave a sensitivity and a specificity of 16.7% and 100%, respectively. The one-point population analysis screening method detected two false positives and 1 false negative, and gave a sensitivity of 83.3% and a specificity and 98.2%. Conclusion: The 2.0 McFarland Etest method had a very good specificity but a poor sensitivity for detecting hVISA. It may be used as an alternative method to confirm detection of hVISA.


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