Development of a Highly Sensitive and Specific Blastomycosis Antibody Enzyme Immunoassay Using Blastomyces dermatitidis Surface Protein BAD-1 (original) (raw)
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Blastomyces dermatitidis Antigen Detection by Quantitative Enzyme Immunoassay
Clinical and Vaccine Immunology, 2012
The second-generation MVista Blastomyces antigen enzyme immunoassay was not quantitative; therefore, specimens obtained previously were tested in the same assay as new specimens to assess the change in antigen levels. Furthermore, the sensitivity in serum had not been fully evaluated. The purpose of this study was to evaluate a quantitative Blastomyces antigen assay and detection of antigen in serum. Calibrators containing known concentrations of Blastomyces galactomannan were used to quantify antigen in urine and serum from patients with proven blastomycosis and from controls. Paired current and previously obtained urine specimens were tested to determine if quantification eliminated the need for concurrent testing to assess change in antigen. Pretreatment of serum with EDTA at 104°C was evaluated to determine if dissociation of immune complexes improved detection of antigenemia. Antigenuria was detected in 89.9% of patients with culture-or histopathology-proven blastomycosis. Specificity was 99.0% in patients with nonfungal infections and healthy subjects, but cross-reactions occurred in 95.6% of patients with histoplasmosis. Change in antigen level categorized as increase, no change, or decrease based on antigen units determined in the same assay agreed closely with the category of change in ng/ml determined from different assays. Pretreatment increased the sensitivity of detection of antigenemia from 35.7% to 57.1%. Quantification eliminated the need for concurrent testing of current and previously obtained specimens for assessment of changes in antigen concentration. Pretreatment increased the sensitivity for detection of antigenemia. Differentiation of histoplasmosis and blastomycosis is not possible by antigen detection.
Detection of Blastomyces dermatitidis antigen in patients with newly diagnosed blastomycosis
Diagnostic Microbiology and Infectious Disease, 2011
Blastomycosis is a serious and potentially fatal infection, and diagnosis can be difficult at times. We evaluated the diagnostic utility of a commercially available assay for detection of Blastomyces dermatitidis antigen, recently modified to permit quantitation, in subjects with newly diagnosed blastomycosis. Twenty-three of 27 (85.1%) subjects had detectable B. dermatitidis antigenuria. In 2 of these 23, positive results were obtained after concentration of the urine specimen. Nine of 11 (81.8%) subjects had detectable B. dermatitidis antigen in serum, including 3 subjects with negative results before treatment of serum with ethylenediaminetetraacetic acid (EDTA) and positive results after EDTA treatment. B. dermatitidis antigen was not detected in specimens from 50 control subjects but was detected in 15 patients with histoplasmosis. B. dermatitidis antigen was detected in most of the patients with blastomycosis and can be a useful tool for timely diagnosis.
Mycopathologia, 1984
We applied a modified immunofluorescence and immunoperoxidase method, utilizing labeled Blastomyces dermatitidis antigens, to look for specific antibody-bearing B/plasma cells in the tissue infiltrates of blastomycosis lesions induced in hamsters. No specific anti-blastomyces antibodies were detectable by this method, although such antibodies were present in blood samples as demonstrated by routine immunodiffusion techniques. These studies suggest that humoral immune reactions do not play a major role in the pathogenesis of lesions of blastomycosis in hamsters.
Open Journal of Veterinary Medicine, 2021
Blastomycosis, the systemic fungal disease of humans and animals caused by Blastomyces dermatitidis and the cryptic species Blastomyces gilchristii, is often misdiagnosed as a bacterial or viral pulmonary disease. Therefore, the development of improved immunodiagnostic assays for this disease has been the primary focus of research in our laboratory. The present study was designed to evaluate four Blastomyces yeast-phase lysate antigenic preparations (human, 597, Eagle River, WI; dog, ERC-2, WI; Human, B5927, Mountain Iron, MN; soil, 85, Georgia, ATCC 56920) for their ability to detect antibody in 48 serum specimens from dogs with diagnosed blastomycosis using an indirect ELISA (STD) compared to a biotin-streptavidin ELISA (B-SA). All four lysate antigens were able to detect antibodies in the specimens with mean absorbance values ranging from 0.930 (B5927) to 1.142 (ERC-2) with the STD ELSA and from 1.395 (B5927) to 1.775 (85) with the B-SA ELISA. The results indicated that both ELISA methods could be utilized for antibody detection, but the B-SA ELISA exhibited greater sensitivity than the STD ELISA with all four of the lysates.
Clinical and Laboratory Update on Blastomycosis
Clinical Microbiology Reviews, 2010
SUMMARY Blastomycosis is endemic in regions of North America that border the Great Lakes and the St. Lawrence River, as well as in the Mississippi River and Ohio River basins. Men are affected more often than women and children because men are more likely to participate in activities that put them at risk for exposure to Blastomyces dermatitidis . Human infection occurs when soil containing microfoci of mycelia is disturbed and airborne conidia are inhaled. If natural defenses in the alveoli fail to contain the infection, lymphohematogenous dissemination ensues. Normal host responses generate a characteristic pyogranulomatous reaction. The most common sites of clinical disease are the lung and skin; osseous, genitourinary, and central nervous system manifestations follow in decreasing order of frequency. Blastomycosis is one of the great mimickers in medicine; verrucous cutaneous blastomycosis resembles malignancy, and mass-like lung opacities due to B. dermatitidis often are confus...
A Real Time PCR Assay for the Identification of Blastomyces dermatitidis in culture and in tissue
Journal of clinical microbiology, 2012
TaqMan((R)) real time polymerase chain reaction assay was developed from the Blastomyces dermatitidis BAD1 gene promoter. The assay identified all haplotypes of B. dermatitidis and five of six positive paraffin embedded tissues. Assay sensitivity was 1 pg genomic DNA of the mold form and 2 CFU of the yeast form of B. dermatitidis. No cross reactivity was observed against other fungal DNA. The assay allowed rapid (5 h) identification of B. dermatitidis from culture and from clinical specimens.
American Journal of Surgical Pathology, 2010
Blastomycosis, a worldwide disease caused by the inhalation of Blastomyces dermatitidis spores, can be diagnosed by microbiologic culture or morphologic identification in tissue or cytologic material. A retrospective review of cases diagnosed as blastomycosis in surgical pathology and cytopathology was undertaken at a University Medical Center to assess the diagnostic value of morphologic methods and their correlation with microbiologic cultures. Surgical pathology/cytology records were reviewed for the period between January 1998 and April 2007 and 53 cases diagnosed as blastomycosis were retrieved: 38 males, 15 females; age 14 to 77 years, median 48. Twenty-nine cases (54.7%) involved lung, 14 (26.4%) soft tissue/bone, 5 (9.4%) skin, 3 (5.6%) other sites, and 2 (3.7%) involved both lung and skin. Forty-six of the 53 patients (87%) had concomitant cultures: 31 (67.4%) were positive for blastomycosis, 11 (23.9%) negative and 4 (8.7%) showed other fungal organisms. A review of microbiology laboratory results for the same period identified a total of 39 patients who were diagnosed with blastomycosis based on isolation of B. dermatitidis. These included 31 cases (79.5%) that were also diagnosed on histology/cytology specimens, 4 (10.25%) that were not submitted to surgical pathology and 4 (10.25%) cases in which pathologic examination failed to identify Blastomyces. This study shows that blastomycosis encountered in surgical/cytopathology can be reliably diagnosed by morphologic examination allowing for prompt treatment. However, microbiologic cultures still play a major role in clinical management of patients suspected of infection because 10.25% were false negative on morphology in our study.
Annals of Tropical Medicine and Public Health
Blastomycosis is a rare but important fungal infection cause by dimorphic fungus Blastomyces dermatitidis.Pneumonia is the most common manifestation and the lung is almost always the organ initially infected. The performance of blastomycosis diagnosis using microscopic examination and culture are highly dependent on the quality of the clinical specimens and the experience of the laboratory personnel. Moreover, these classical methods have previously shown lower sensitivity in fungal detection compared to molecular methods.Determination the frequency of pulmonary blastomycosis in patients with respiratory symptoms by using conventional (Wet mounting, culture and cytology) and molecular methods (conventional PCR and real time PCR), then comparing between conventional and molecular methods concerning sensitivity and specificity.This study involved 132patients who attended