Comparison of the Sensititre YeastOne and Fungitest methods with the NCCLS M27-A2 reference method for antifungal susceptibility testing of yeasts

Background: The recent introduction of Sensititre YeastOne, a colorimetric microdilution method that includes new antifungal agents has opened the field to MIC’s determination by an easy-to-perform method. The aim of this study was to compare this test with the NCCLS M27-A protocol and with Fungitest, a current routine method for yeasts susceptibility testing. Methods: Sensititre YeastOne method (Trek diagnostic), and the NCCLS M27-A2 were performed on 300 yeasts clinical isolates distributed as follow: 125 C. albicans, 273 non-albicans species. Four antifungal agents were tested by the reference method: amphotericine B (AmB), fluconazole (FZ), itraconazole (ITZ), and voriconazole (VOR). The reading of the Sensititre and NCCLS results was visually performed after 24 and 48 h respectively. The Fungitest (Biorad) method was applied on 121 among the 300 isolates and the reading was made after 24 to 48 h incubation time according to the positive control growth. Results: By the NCCLS method, the MICs50/MICs90 (µg/ml) were as follows: 1/2 (AmB); 16/64 (FZ); 0.25/4 (ITZ) and 0.125/2 (VOR). Sensititre vs. NCCLS: The overall agreement within 2 dilutions for AmB, FZ, ITZ and VOR was respectively 54, 82, 80 and 78%. The MICs50/MICs90 were in absolute concordance for VOR by both techniques. Very major errors (%) were recorded as follows: 0.01/0 (AmB with a MIC ≥ 4/8µg/ml for resistant strains respectively), 1.6 (FZ), 3.6 (ITZ) and 2.3 (VOR with a MIC ≥ 8µg/ml for resistant strains). Fungitest vs. NCCLS: The agreement between both methods including minor discrepancies was 98% (AmB), 88% (FZ) and 98% (ITZ). Following the breakpoints given by the manufacturer, very major errors were 6.3% for FZ, 0.03% for ITZ and none for AmB. Conclusions: Sensititre is a convenient alternative to the NCCLS method for yeast susceptibility testing. Fungitest in spite of good correlations must change the breakpoints and include new antifungal agents to be competitive

Rapid intrapartum test (Strep B OIA) and prenatal cultures for identification of group B streptococcal carriers at delivery: a prospective study

peer reviewedBackground: The efficacy of the prenatal screening-based approach recommended by the CDC to prevent neonatal GBS diseases could be improved by using a good rapid test performed at the onset of labor. To assess the Strep B OIA® test (Biostar, Boulder, Co), completed in 30 minutes, we initiated a 6-center study to compare it with prenatal screening cultures to identify GBS carriers at delivery or opportunities to initiate intrapartum antibioprophylaxis (IAP). Methods: For a total of 539 pregnant women included in the study, pairs of vaginal/anal specimens collected at 35-37 weeks and intrapartum vaginal specimens were plated onto colistin-nalidixic agar and then inoculated into selective LIM broth for the detection of GBS. Furthermore, on each intrapartum vaginal swab a Strep B OIA test was performed. Results: GBS were recovered in culture from 89 prenatal screenings (17%) and from 71 specimens collected at delivery (13%). Strep B OIA test identified 48 positive specimens (9%). Respectively, for the identification of GBS carriers at delivery, sensitivity, specificity, positive and negative predictive values for prenatal screening cultures were 69%, 91%, 55% and 95% and for Strep B OIA tests they were 63%, 99%, 94% and 95%. Evaluating opportunities to start an IAP, based on Strep OIA test versus prenatal screening cultures, 45 IAP vs. 49 would have been useful, 3 vs. 40 useless (P< 0,001) and 26 vs. 22 missed. Conclusion: To identify GBS carriers, the Strep B OIA test, performed at the time of onset of labor is equally sensitive to prenatal screening cultures and would allow a highly significant reduction of useless IAP

Prevalence of ermB, ermTR and mefA/B gene classes among erythromycine resistant group B streptococcus isolates collected in Belgium

Background: Emergence of erythromycin (Er) and clindamycin (C) resistance (R) observed in GBS, is currently becoming recognized. Methods: Clinical isolates were obtained from a Belgian surveillance for invasive GBS disease in newborns and adults in 1996-1998 (N1=235) and from consecutive specimens submitted, during 1999-2000, to the University hospital of Liege (N2=165). MICs of Er were determined buy using Etest® strip (interpretive criteria of NCCLS). Furthermore, for the ErR isolates, the inducible (iMLS), constitutive (cMLS) and M phenotypes were assessed by disk diffusion and by a double-disk test; the distribution of genes encoding RNA methylases and efflux pumps was investigated by PCR. Results: Of the N1 and N2 isolates, 16 (6.8%) and 19 (11.5%) were respectively R to Er. Among these 35 ErR isolates, 21 (60%) exhibited the cMLS phenotype. They demonstrated a high level R to Er with MICs ranging from 16 to >256 mg/L. The ermB gene was harbored by 19/21 isolates, the ermTR gene by 1 isolate and both ermB and ermTR were present in another isolate. The iMLS phenotype was observed in 10 (29%) ErR isolates; the ermTR gene was present in all isolates except one harboring an ermTR gene. These strains demonstrated low level of R to Er, with MICs of 1-12 mg/L. All 4 isolates (11%) expressing an M phenotype, displayed low level R to Er alone (MICs, 2 mg/L) and were positive for the mefA/B gene. Conclusion: In Belgium, by year 2000, prevalence of R to macrolide in GBS exceeded 10%. R was mainly caused by target-site modification (ermB, ermTR) mechanisms; efflux (mefA/B) R mechanism was also prevalent among the isolates tested. These results indicate the possibility of inappropriate prophylaxis or therapy using C or E as the recommended alternatives in penicillin-allergic patients

Pediatric Life-Threatening Coronavirus Disease 2019 With Myocarditis.

We report the case of a pediatric life-threatening coronavirus disease 2019 who presented as myocarditis with heart failure. Clinicians should be aware of this severe presentation of the disease in children, possibly linked to an exaggerated inflammatory host immune response to severe acute respiratory syndrome coronavirus 2