R St Amand | PubMed Health

PubMed1997

Comparison of the Vidas and Bio-Whittaker enzyme immunoassays for detecting IgG reactive with varicella-zoster virus and mumps virus.

A total of 215 sera, 164 positive and 51 negative for antibody reactive with varicella-zoster virus (VZV), were analyzed using two commercially available enzyme immunoassays (EIAs) for detecting VZV-IgG, the Vidas Varicella-Zoster IgG assay (bioMeriéux Vitek, Inc., Hazelwood, MO, USA) and the Bio-Whittaker Varicella II assay (Bio-Whittaker, Inc., Walkersville, MD). The sensitivity and specificity of the Vidas and EIA for VZV-IgG was 98.9 and 100%, respectively. The sensitivity of the Bio-Whittaker VZV-IgG EIA assay was 98.8%, specificity 96.1%. Equivocal results were obtained with 4 and 2 sera, respectively. A total of 185 sera, 169 positive and 16 negative for mumps virus antibody, were analyzed with Vidas and Bio-Whittaker mumps IgG EIAs. The sensitivity of the two assays for detecting mumps IgG was 99.4% and 95.7%, respectively. Both assays demonstrated 100% specificity. Two of the 185 sera tested for mumps antibody yielded equivocal results with the Vidas EIA; four equivocal results were obtained with the Bio-Whittaker EIA.

Antibodies, Viral↗

PubMed1994

Revised disk diffusion interpretive criteria for cefaclor, loracarbef, cefprozil and cefixime when testing Haemophilus influenzae on haemophilus test medium.

The aim of the current five-center collaborative study was to reassess the interpretive criteria for cefaclor, loracarbef, cefprozil and cefixime previously adopted or proposed by the National Committee for Clinical Laboratory Standards (NCCLS) for disk diffusion susceptibility tests with Haemophilus influenzae on Haemophilus Test Medium (HTM) agar. MICs and zones of inhibition were determined using NCCLS methods, HTM and two collections of strains of Haemophilus influenzae. One group of strains consisted of 118 stock organisms taken largely from various recent U.S. antibiotic resistance surveillance studies. The emphasis in this selected group of organisms was on strains that were beta-lactamase negative but ampicillin resistant (BLNAR) by some other mechanism. The second collection of test organisms consisted of 50 recent clinical isolates of Haemophilus influenzae obtained from each of the five participating study centers. This group was considered representative of the type of Haemophilus influenzae currently recovered from clinical sources in the USA. Frequency distribution assessment and error-rate bounded analysis of scattergram comparisons of MICs and zone sizes were used to develop the following zone diameters interpretive for disk diffusion susceptibility tests with Haemophilus influenzae on HTM agar: cefaclor, > or = 20 mm (susceptible, S) and < or = 16 mm (resistant, R); loracarbef, > or = 19 mm (S) and < or = 15 mm (R); and cefprozil, > 18 mm (S) and < 14 mm (R). The respective MIC correlates for all three antimicrobial agents were < or = 8 micrograms/ml (S) and 32 micrograms/ml (R).(ABSTRACT TRUNCATED AT 250 WORDS)

Cefaclor↗