Biomedical subjects

Mimi Healy

Publications and source records attributed to Mimi Healy.

5 recordsLinked to original sources

PubMed2005

Zygomycosis in a tertiary-care cancer center in the era of Aspergillus-active antifungal therapy: a case-control observational study of 27 recent cases.

BACKGROUND: Anecdotal evidence suggests a rise in zygomycosis in association with voriconazole (VRC) use in immunosuppressed patients. METHODS: We performed prospective surveillance of patients with zygomycosis (group A; n = 27) and compared them with contemporaneous patients with invasive aspergillosis (group B; n = 54) and with matched contemporaneous high-risk patients without fungal infection (group C; n = 54). We also performed molecular typing and in vitro susceptibility testing of Zygomycetes isolates. RESULTS: Nearly all patients with zygomycosis either had leukemia (n = 14) or were allogeneic bone marrow transplant recipients (n = 13). The Zygomycetes isolates (74% of which were of the genus Rhizopus) had different molecular fingerprinting profiles, and all were VRC resistant. In multivariate analysis of groups A and C, VRC prophylaxis (odds ratio [OR], 10.37 [95% confidence interval [CI]], 2.76-38.97]; P = .001), diabetes (OR, 8.39 [95% CI, 2.04-34.35]; P = .003), and malnutrition (OR, 3.70 [95% CI, 1.03-13.27]; P = .045) were found to be independent risk factors for zygomycosis. Between patients with zygomycosis (after excluding 6 patients with mixed mold infections) and patients with aspergillosis, VRC prophylaxis (OR, 20.30 [95% CI, 3.85-108.15]; P = .0001) and sinusitis (OR, 76.72 [95% CI, 6.48-908.15]; P = .001) were the only factors that favored the diagnosis of zygomycosis. CONCLUSIONS: Zygomycosis should be considered in immunosuppressed patients who develop sinusitis while receiving VRC prophylaxis, especially those with diabetes and malnutrition.

APACHE↗

PubMed2005

Microbial DNA typing by automated repetitive-sequence-based PCR.

Repetitive sequence-based PCR (rep-PCR) has been recognized as an effective method for bacterial strain typing. Recently, rep-PCR has been commercially adapted to an automated format known as the DiversiLab system to provide a reliable PCR-based typing system for clinical laboratories. We describe the adaptations made to automate rep-PCR and explore the performance and reproducibility of the system as a molecular genotyping tool for bacterial strain typing. The modifications for automation included changes in rep-PCR chemistry and thermal cycling parameters, incorporation of microfluidics-based DNA amplicon fractionation and detection, and Internet-based computer-assisted analysis, reporting, and data storage. The performance and reproducibility of the automated rep-PCR were examined by performing DNA typing and replicate testing with multiple laboratories, personnel, instruments, DNA template concentrations, and culture conditions prior to DNA isolation. Finally, we demonstrated the use of automated rep-PCR for clinical laboratory applications by using isolates from an outbreak of Neisseria meningitidis infections. N. meningitidis outbreak-related strains were distinguished from other isolates. The DiversiLab system is a highly integrated, convenient, and rapid testing platform that may allow clinical laboratories to realize the potential of microbial DNA typing.

Automation↗

PubMed2005

Molecular characterization of hand flora and environmental isolates in a community setting.

We analyzed 69 bacterial isolates, comprising seven species of gram-negative bacterial rods and three species of coagulase-negative staphylococci, recovered from both the hands of caretakers and their environment in households sampled in upper Manhattan. Repetitive sequence-based PCR and dendrogram analysis were used to determine strain similarity. Greater than 25% of individual species of Acinetobacter, Enterobacter, and coagulase-negative staphylococci recovered from the hands and immediate environment within each household shared the same genotype. This study is the first to demonstrate the frequency of bacteria shared within community households. These strains may serve as potential reservoirs for either community- or hospital-acquired infections.

Coagulase↗

PubMed2005

Repetitive-sequence-PCR-based DNA fingerprinting using the Diversilab system for identification of commonly encountered dermatophytes.

The performance of repetitive-sequence-based PCR (rep-PCR) using the DiversiLab system for identification of dermatophytes commonly isolated in a clinical laboratory was assessed by comparing results to those of conventional tests (colony morphology, microscopic examination of slide cultures, and, for suspected Trichophyton species, use of additional media). Sixty-one cultures were tested in phase 1, the feasibility portion of the study; 64 additional cultures were tested in phase 2, the validation portion conducted to assess reproducibility and confirm accuracy. Discrepancies were resolved by repeating rep-PCR and conventional tests and, in phase 2, sequencing the internal transcribed spacers. After initial testing of the cultures in phase 1 (excluding one contaminated culture), agreement between conventional tests and rep-PCR was 90% (54 of 60). Agreement was 98.3% after resolution of discrepancies, and in all but one case the initial rep-PCR result was correct. After initial testing of cultures in phase 2 (excluding one discarded and one contaminated culture), agreement between rep-PCR and conventional testing was 88.7% (55 of 62). After discrepancies were resolved, agreement was 100%. Initial rep-PCR results were correct, except for one Microsporum canis culture containing two colony variants, which could not be initially identified by rep-PCR. The performance of the DiversiLab system for identification of the dermatophytes commonly encountered in a clinical mycology laboratory-Trichophyton mentagrophytes, Trichophyton rubrum, Trichophyton tonsurans, and M. canis-was excellent. Moreover, the DiversiLab system is technically simple and provides results in < 24 h once a pure culture is available for testing, which is considerably more rapid than conventional identification tests.

Arthrodermataceae↗

PubMed2003

Clinical evaluation of two methods for genotyping hepatitis C virus based on analysis of the 5' noncoding region.

We compared the performance characteristics of a standardized direct sequencing method (TRUGENE HCV 5'NC; Visible Genetics Inc., Toronto, Ontario, Canada) and a reverse hybridization line probe assay (INNO-LiPA HCV II; Bayer Corp., Tarrytown, N.Y.) for genotyping of hepatitis C virus (HCV). Both methods are based on detection of sequence heterogeneity in the 5' noncoding (5'NC) region. Concordance between the genotyping methods was assessed by testing 172 samples representing the six major genotypes. Sequence analysis of the more phylogenetically informative nonstructural 5B (NS5B) region was also done with 148 (86%) samples to confirm the accuracy of and resolve discrepancies between the 5'NC genotyping results. The sensitivities of the methods were assessed by using the 5'NC amplicon from both the qualitative and quantitative AMPLICOR HCV tests (Roche Diagnostics Corp., Indianapolis, Ind.). The ability of the methods to detect mixed-genotype infections was determined with mixtures of two different genotypes at relative concentrations ranging from 1 to 50%. Both 5'NC methods were able to genotype 99.4% of the samples with type agreement for 99.5% and subtype agreement for 68.2% of the samples. No or ambiguous subtype results were found by the line probe assay for 16.5% and by the TRUGENE 5'NC test for 17.1% of the samples. Discrepancies occurred between the line probe assay and NS5B results at the type level for 1.4% of the samples and at the subtype level for 14.2% of the samples. Discrepancies also occurred between the TRUGENE 5'NC and NS5B results at the type level for 2% of the samples and at the subtype level for 8.1% of the samples. We also found two distinct strains of HCV classified as type 2 by analysis of the 5'NC region that were type 1 by analysis of the NS5B region. The sensitivities of the two 5'NC genotyping methods were comparable and dependent on the amplification test used ( approximately 10(3) IU/ml with the qualitative HCV RNA tests and approximately 10(5) IU/ml with the quantitative HCV RNA tests). Genotype mixtures were successfully identified at a relative concentration of 5% by the line probe assay and 10% by the TRUGENE 5'NC test. In conclusion, the performance characteristics of the 5'NC methods were similar and both methods produced accurate results at the genotype level but neither method should be used for subtyping.

5' Untranslated Regions↗