<i>Blastomyces dermatitidis</i>Antibody Responses in Serial Serum Specimens from Dogs with Blastomycosis: Comparison of Different Yeast Lysate Antigens

The systemic fungal organism, Blastomyces dermatitidis causes blastomycosis in animals and hu-mans. This study was designed to evaluate antibody detection in 55 serial serum specimens from 9 dogs with blastomycosis using B. dermatitidis yeast lysate antigens produced from two human isolates (B5896;B5931) and two dog isolates (ERC-2;T-58) with the indirect enzyme linked im-munosorbent assay (ELISA;peroxidase system) to determine an optimal lysate antigen(s) for use in the ELISA to detect antibody in the dog serum specimens. The mean absorbance values when the lysate antigens were compared with respect to their ability to detect antibody in the day 0 sera from the 9 dogs were 1.024 (ERC-2), 1.351 (B5896), 1.700 (B5931) and 2.084 (T-58) respectively. All of the reagents exhibited a high level of sensitivity and in all instances the amount of antibody declined as the time interval post-treatment increased, but the T-58 lysate prepared from the dog isolate from Tennessee was the optimal reagent. We continue to evaluate antigens for B. derma-titidis antibody detection in different immunodiagnostic assays.

Antigen Detection in Canine Blastomycosis: Comparison of Different Antibody-Antigen Combinations in Two Competitive ELISAs

This present study was designed to evaluate four different Blastomyces dermatitidis antibody-antigen combinations (B5896 and T-58 antibodies and B5896 and WI-R antigens) for the detection of antigen in 36 urine specimens from dogs with blastomycosis using a standard indirect ELISA (STD) and a biotin-streptavidin ELISA (B-SA). The antigen detection sensitivity values ranged from 81% (B-SA: T-58 Ab + WI-R Ag) to 100% (STD and B-SA: B5896 Ab + WI-R Ag;B5896 Ab + B5896 Ag) with the antibody-antigen combinations in the two assays. Optimal detection was evidenced when the B5896 Ab was allowed to react with the urine specimens for 30 min at 37?C and then placed in the B-SA ELISA plates containing the B5896 Ag. The greatest absorbance value obtained with this antibody-antigen com-bination was 0.903 (range of 0.596 - 0.903) as compared to the control value of 1.246. The difference between the control absorbance and the test absorbance values was 0.343 which was considerably greater than the control-test values with the other combinations. This study thus showed that the results obtained in antigen detection assays are dependent upon the antibody used to react with the urine specimens as well as the antigen used in the enzyme immunoassay.

Comparative antibody study for antigen detection in urine specimens for diagnosis of blastomycosis using a competitive enzyme-linked immunosorbent assay

Diagnosis of blastomycosis is often done using a combination of clinical signs and cytologic or histopathologic identification of the organism, Blastomyces dermatitidis, from infected tissues. However, these methods are time consuming, invasive, and still lead to misdiagnosis. A competitive enzyme-linked immunosorbent assay (ELISA) can be used for detection of B. dermatitidis antigens, which are present in urine specimens of infected patients. The current study evaluates the use of various antibodies for detection of antigen in dog urine specimens, to provide a better diagnosis of blastomycosis in the future. Our results show that different antibodies against B. dermatitidis produce various sensitivities for antigen detection. The most realistic antibodies for immunodiagnostic tests would be antibodies that can be obtained in larger quantities, i.e. vaccination using a yeast lysate in a laboratory setting. We found that these antibodies produce a comparable and reliable result to that of antibodies obtained from an infected patient.

Detection of Antibody in Dogs with Blastomycosis Using <i>Blastomyces dermatitidis</i>Yeast Phase Lysate Antigens

The objective of our study was to compare two B. dermatitidis yeast phase lysate antigens [ERC-2, dog Wisconsin;85, soil Georgia, ATCC 56,920] for detecting antibody in 38 serum specimens [pre-treatment, 30-day, and 60-day post treatment] from dogs with diagnosed blastomycosis. The mean absorbance values obtained with the two antigens (N = 38) were ERC-2 = 2.359 and 85 = 2.189. The mean absorbance values when the sera were divided into the three treatment groups were as follows pre-treatment: Isolate ERC-2 had an absorbance value of 2.418;Isolate 85 had an absorbance value of 2.688, 30-day post treatment: ERC-2 had an absorbance value of 2.452;85 had an absorbance value of 2.303 and 60-day post treatment: ERC-2 had an absorbance value of 2.150;85 had an absorbance value of 2.073 with the mean absorbance values of all treatment groups were ERC-2: 2.229 and 85: 2.141. This study indicates the potential for further evaluations of the two lysate antigens with regard to antibody detection in dog sera with the ERC-2 reagent slightly more reactive than the 85 lysate antigen.

Detection of Antibodies in Serum Specimens from Dogs with Blastomycosis with Lysate Antigens Prepared from Four <i>Blastomyces dermatitidis</i>Dog Isolates: Individual Antigens vs Antigen Combinations

Blastomycosis, the systemic fungal infection of humans and animals, has presented a diagnostic challenge to clinicians and laboratory personnel for many years. Our laboratory has been concentrating on attempting to develop antigenic reagents from the yeast phase of various isolates of Blastomyces dermatitidis and to evaluate these lysate antigens with regard to antibody detection in blastomycosis. The aim of this current study was to evaluate yeast phase antigens prepared from four dog isolates of B. dermatitidis and to evaluate their efficacy, when used individually or in combination, for antibody detection in sera from dogs with blastomycosis. Mean absorbance values using the ELISA to assay 24 serum specimens (Trial 1) ranged from 0.588 with an individual lysate antigen to 0.992 when three reagents were combined. Eight of the lysates exhibited mean absorbance values ranging from 0.992 to 0.915 with 7 out of 8 being lysate antigen combinations. Mean absorbance values with the other 6 lysates ranged from 0.899 to 0.588. In Trial 2, the 6 most sensitive reagents from Trial 1 were assayed against 10 highly reactive dog sera. The results of Trial 2 showed that 5 antigen combinations detected antibody to a greater degree than the individual lysate antigen. Combinations of northern and southern antigens were able to detect antibody in serum specimens from either of these geographical regions. Comparative studies are continuing to further evaluate various lysate antigen combinations for antibody detection in blastomycosis.

Comparison of Two Enzyme Immunoassays and Four Lysate Antigens for the Detection of Antibody in Canine Blastomycosis

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.

Extrahepatic cholestasis associated with paracoccidioidomycosis:Challenges in the differential diagnosis of biliopancreatic neoplasia

BACKGROUND Paracoccidioidomycosis(PCM)may involve the hepatic pedicle and peripan creatic lymph nodes,cause damage to the bile duct and manifest,exceptionally,in combination with extrahepatic cholestasis(EHC),making investigation and treatment challenging.AIM To investigate the management of patients with visceral PCM admitted with EHC.METHODS All patients diagnosed with PCM treated in a public,tertiary teaching hospital between 1982 and 2020 were retrospectively evaluated.Those also identified with EHC were allocated to two groups according to the treatment approach for the purpose of comparing clinical,laboratory,and imaging findings,resources used for etiological diagnosis,treatment results,and prognosis.Statistical analyses were performed using the linear mixed-effects model(random and fixed effects),which was adjusted using the PROC MIXED procedure of the SAS®9.0 software,and Fisher’s exact test.RESULTS Of 1645 patients diagnosed with PCM,40(2.4%)had EHC.Of these,20(50.0%)lived in the rural area and 29(72.5%)were men,with a mean age of 27.1 years(3-65 years).Jaundice as first symptom and weight loss of at least 10 kg were observed in 16 patients(40.0%),and a mass in the head of the pancreas was observed in 8(20.0%).The etiological diagnosis was made by tissue collection during surgery in 4 cases(10.0%)and by endoscopic methods in 3 cases(7.5%).Twenty-seven patients(67.5%)received drug treatment alone(Group 1),whereas 13(32.5%)underwent endoscopic and/or surgical procedures in combination with drug treatment(Group 2).EHC was significantly reduced in both groups(40.7% in Group 1,with a mean time of 3 months;and 38.4% in Group 2,with a mean time of 7.5 months),with no statistically significant difference between them.EHC recurrence rates,associated mainly with treatment nonadherence,were similar in both groups:37% in Group 1 and 15.4% in Group 2.The mortality rate was 18.5% in Group 1 and 23% in Group 2,with survival estimates of 71.3% and 72.5%,respectively,with no statistically significant difference.CONCLUSION Although PCM-related EHC is rare,it needs to be included in the differential diagnosis of malignancies,as timely treatment can prevent hepatic and extrahepatic sequelae.

Blastomycosis in China： a case report and literature review

Blastomycosis is a fungal disease that is endemic in parts of North America. It is very rare in China and also commonly misdiagnosed, often as cancer or other infectious diseases. The clinical profile of a case of disseminated blastomycosis with pulmonary changes and skin ulcers was described. He had been misdiagnosed with tuberculosis, after adequate therapy with a lipid formulation of amphotericin B, followed by itraconazole, the lung and skin lesions improved. Then the five cases reported in China and literatures were reviewed. The aim of this report was to improve the knowledge regarding blastomycosis for physicians in China to avoid delaying adequate therapy.

Central nervous system blastomycosis presenting as a year-long chronic headache

This case describes a posterior fossa mass due to blastomycotic infection in a non-immunocompromised 41-year-old male presenting with a chronic headache for over one year.Given the risk of herniation,no lumbar puncture could be performed.A full work-up found no evidence of systemic infection.Surgical resection helped identify the mass as a blastomycotic abscess.Magnetic resonance imaging characteristics of the mass were helpful in the identification of the mass as a fungal abscess.

An Incidental Finding and Unusual Presentation of Atypical Coccidioidomycosis in a 72-Year-Old Man: A Case Report

This case report presents an unusual and challenging diagnostic scenario involving a 72-year-old man who recently returned from a trip to Maui, Hawaii. While in Maui, the patient presented with a fever and fatigue that resolved spontaneously. However, he had an observable rash on his head and was given a steroid injection to resolve the rash. Later on his trip, the patient experienced a dry, nonproductive cough which resolved with a five-day course of prednisone. While visiting Michigan, the patient began to experience neck pain and visited Troy Beaumont Hospital for further treatment. Meningitis tests were negative. Vancomycin was given due to the detection of gram positive coccidioidomycosis in the culture, but this was later proven to be a contaminant. Coccidiomycosis does not initially have specific symptoms. Despite negative coccidioidomycosis antigen tests, the patient exhibited features more consistent with blastomycosis and cryptococcus, highlighting the complexities of diagnosing fungal infections with atypical presentations. The case emphasizes the importance of considering alternative fungal pathogens native to endemic regions and pursuing comprehensive diagnostic measures to establish an accurate diagnosis. Lastly, the discussion about recommendations for antifungal therapy and preventative measures for individuals at risk of respiratory fungal infections is critically important for the advancement of early detection of fungal infections.

Sensitivity and Specificity Determinations with Isoelectric Focusing Fractions of <i>Blastomyces dermatitidis</i>for Antibody Detection in Serum Specimens from Infected Dogs

Blastomycosis and histoplasmosis manifest as lung and systemic fungal infections in mammals caused by Histoplasma capsulatum, and Blastomyces dermatitidis. These infections exhibit cross reactivity of antibodies which makes a correct diagnosis potentially elusive. The purpose of this study was to gain an understanding of which isoelectric focusing fractions (RotoforTM) of B. dermatitidis were reactive or cross reactive with serum specimens from dogs infected with B. dermatitidis, H. capsulatum, and Cryptococcus neoformans. Three serum specimens from dogs that were infected with B. dermatitidis, two dogs infected with H. capsulatum, and one dog infected with C. neoformans were assayed against the 20 B. dermatitidis RotoforTM fractions. Reactivity was determined using the indirect enzyme linked immunoassay (ELISA). Reactivity with B. dermatitidis was found predominantly in the protein fractions 1 - 6, and cross reactivity with H. capsulatum, and C. neoformans sera was found within the B. dermatitidis protein fractions 15 - 19.

Comparison of Detection of Antibodies with Yeast Lysate Antigens Prepared from Two Isolates of <i>Blastomyces dermatitidis</i>by Two Different Methods: Sensitivity and Specificity Evaluations

Blastomycosis, a systemic fungal disease, caused by the dimorphic fungus Blastomyces dermatitidis, has continually presented clinicians with concerns with regard to laboratory diagnosis and prevention. For years researchers have strived to develop antigens with a high degree of sensitivity and specificity. The purpose of this study was to gain a bet- ter understanding of how two novel yeast lysate antigens, prepared from two B. dermatitidis isolates by different meth- ods, would be able to detect antibody responses in immunized rabbits in a specific and sensitive manner. The en- zyme-linked immunosorbent assay (ELISA) was used to evaluate antibody in serum specimens with yeast lysate re- agents prepared after allowing yeast cells to lyse for 1 or 7 days. The results indicated that reactivity was greater with the day 7 antigens, with both the B5896 and 597 B. dermatitidis isolates, when compared to the day 1 antigens;in con- trast the day 1 preparations exhibited less cross reactivity when assayed against anti-Histoplasma capsulatum serum specimens.

Comparison of Antibody Detection with Yeast Lysate Antigens Prepared from Blastomyces dermatitidis Dog Isolates from Wisconsin and Tennessee

Blastomyces dermatitidis, the causative agent of blastomycosis, a potentially lethal dimorphic fungal disease of humans and animals has been difficult to diagnose in the clinical laboratory. We are attempting to develop and improve immunodiagnostic assays by producing novel yeast lysate reagents for the detection of antibodies in blastomycosis. The objective of this study was to use lysate antigens prepared from four B. dermatitidis antigens isolated from dogs infected with blastomycosis from two different endemic areas (Wisconsin and Tennessee) testing for the detection of antibodies in serum specimens from immunized rabbits and infected dogs using the indirect ELISA. In the dog sera, absorbance values ranged from 0.774 to 1.350, while the rabbit sera values ranged from 0.533 to 1.191. Antigen T-58 appeared to lack any geographical specificity in antibody detection, which could prove useful in future immunodiagnostic detection of blastomycosis infections.