Simplified method for producingParacoccidioidesbrasiliensisexoantigens for use in immunodiffusion tests

Analysis and Interpretation of Automated Blood Count in the Treatment of Chronic Paracoccidioidomycosis

Blood count is crucial for assessing bone marrow's cell production and differentiation during infections, gaging disease severity, and monitoring therapeutic responses. The profile of blood count in chronic forms of paracoccidioidomycosis (PCM) has been insufficiently explored. To better understand the changes in hematological cells in different stages of the PCM chronic form, we evaluated the blood count, including immature blood cells in automated equipment, before and during the treatment follow-up of 62 chronic PCM patients. Predominantly male (96.8%) with an average age of 54.3 (standard deviation SD 6.9) years, participants exhibited pre-treatment conditions such as anemia (45.2%), monocytosis (38.7%), and leukocytosis (17.7%), which became less frequent after clinical cure. Anemia was more prevalent in severe cases. Notably, hemoglobin and reticulocyte hemoglobin content increased, while leukocytes, monocytes, neutrophils, immature granulocytes, and platelets decreased. Chronic PCM induced manageable hematological abnormalities, mainly in the red blood series. Monocytosis, indicating monocytes' role in PCM's immune response, was frequent. Post-treatment, especially after achieving clinical cure, significant improvements were observed in various hematological indices, including immature granulocytes and reticulocyte hemoglobin content, underscoring the impact of infection on these parameters.

Standardization of Semi-Quantitative Dot Blotting Assay-Application in the Diagnosis, Follow-Up, and Relapse of Paracoccidioidomycosis

INTRODUCTION

This study standardized a semi-quantitative dot blotting assay (DB) and a quantitative real-time polymerase chain reaction (qPCR) to detect specific antibodies for Paracoccidioides brasiliensis and its DNA in PCM patients.

METHODOLOGY

We evaluated 42 confirmed PCM patients upon admission using a serological double agar gel immunodiffusion test (DID), DB, and molecular tests (qPCR in total blood). The control groups included 42 healthy individuals and 37 patients with other infectious diseases. The serological progress during treatment was evaluated in eight patients, and there was a relapse diagnosis in ten patients using the Pb B.339 strain antigen. The cut-off points for the serological tests were determined by a receiver operator characteristic curve.

RESULTS

The DB and DID tests showed similar accuracy, but the DB identified lower antibody concentrations. Cross-reactions were absent in the DB assay. In the relapse diagnoses, DB exhibited much higher sensitivity (90%) than DID (30%).

CONCLUSIONS

A DB assay is easier and faster than a DID test to be performed; DB and DID tests show the same accuracy, while blood qPCR is not recommended in the diagnosis at the time of admission; cross-reactions were not observed with other systemic diseases; DB and DID tests are useful for treatment monitoring PCM patients; and a DB assay is the choice for diagnosing relapse. These findings support the introduction of semi-quantitative DB assays in clinical laboratories.

Fast and cost-effective protocol to produce Paracoccidioides spp. antigens

INTRODUCTION

The existing methods for Paracoccidioides spp. antigen production are problematic in terms of standardization, specificity, stability, repeatability, and reproducibility.

OBJECTIVE

To optimize the methodology for Paracoccidioides spp. antigen production and evaluate its applicability in paracoccidioidomycosis immunodiagnosis.

MATERIALS AND METHODS

The antigens were obtained from Paracoccidioides lutzii isolates (01, 66, and 8334), Paracoccidioides brasiliensis sensu stricto (113), and Paracoccidioides restripiensis (B-339). These fungi were grown at 36 °C ± 1 °C, on modified Fava-Netto agar, according to Freitas et al. (2018). Paracoccidioides lutzii antigens were obtained after , 10, and 20 days of culture, whereas P. brasiliensis and P. restripiensis antigens were obtained after 10 days. Antigens were evaluated in natura, 10 and 20 times concentrated. Antigenic capacity was evaluated using a double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, and aspergillosis, and random blood donors.

RESULTS

Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis, P. restrepiensis antigens, and P. lutzii antigens were evaluated with the polyclonal antibodies against P. lutzii and P. brasiliensis, respectively. No cross-reactivity was obtained for polyclonal antibodies against Histoplasma capsulatum, Aspergillus fumigatus, and random blood donors. The proposed protocol allowed stable, repeatable, and reproducible genus-specific antigen production at a low cost and in a short cultivation time.

CONCLUSION

The proposed protocol allowed us to obtain genus-specific antigens that can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is a neglected disease, contributing to an early diagnosis, especially in endemic regions, regardless of the species.

Diagnosis and Treatment of Pulmonary Coccidioidomycosis and Paracoccidioidomycosis

Coccidioidomycosis (CM) and paracoccidioidomycosis (PCM) are systemic mycoses that are highly endemic in Latin America and have recently been included on the World Health Organization (WHO) Fungal Priority Pathogens List. Coccidioides immitis and Coccidioides posadasii are recognized as etiological agents of CM, with peculiarities in their geographic distribution. The genus Paracoccidioides now includes Paracoccidioides lutzii and the Paracoccidioides brasiliensis complex, which encompasses four phylogenetic species. In both diseases, pulmonary signs and symptoms are the main reasons for patients to seek medical assistance, and they are frequently misdiagnosed as tuberculosis. In this paper, we present a critical view of the strategies for diagnosis and clinical management of CM and PCM. Over the past few decades, there has been an increase in the number of reports of endemic fungal infections in areas previously thought to be "non-endemic" due to climate change and increased travel, among other factors. Learning to recognize their main epidemiological aspects and clinical manifestations is crucial so that clinicians can include them in the differential diagnosis of lung disease and avoid late diagnosis.

Paracoccidioidomycosis: Current Status and Future Trends

Paracoccidioidomycosis (PCM), initially reported in 1908 in the city of São Paulo, Brazil, by Adolpho Lutz, is primarily a systemic and neglected tropical mycosis that may affect individuals with certain risk factors around Latin America, especially Brazil. Paracoccidioides brasiliensis sensu stricto, a classical thermodimorphic fungus associated with PCM, was long considered to represent a monotypic taxon. However, advances in molecular taxonomy revealed several cryptic species, including Paracoccidioides americana, P. restrepiensis, P. venezuelensis, and P. lutzii, that show a preference for skin and mucous membranes, lymph nodes, and respiratory organs but can also affect many other organs. The classical diagnosis of PCM benefits from direct microscopy culture-based, biochemical, and immunological assays in a general microbiology laboratory practice providing a generic identification of the agents. However, molecular assays should be employed to identify Paracoccidioides isolates to the species level, data that would be complemented by epidemiological investigations. From a clinical perspective, all probable and confirmed cases should be treated. The choice of treatment and its duration must be considered, along with the affected organs, process severity, history of previous treatment failure, possibility of administering oral medication, associated diseases, pregnancy, and patient compliance with the proposed treatment regimen. Nevertheless, even after appropriate treatment, there may be relapses, which generally occur 5 years after the apparent cure following treatment, and also, the mycosis may be confused with other diseases. This review provides a comprehensive and critical overview of the immunopathology, laboratory diagnosis, clinical aspects, and current treatment of PCM, highlighting current issues in the identification, treatment, and patient follow-up in light of recent Paracoccidioides species taxonomic developments.

Paracoccidioidomycosis: What We Know and What Is New in Epidemiology, Diagnosis, and Treatment

Paracoccidioidomycosis (PCM) is a systemic mycosis endemic to Latin America caused by thermodimorphic fungi of the genus Paracoccidioides. In the last two decades, enhanced understanding of the phylogenetic species concept and molecular variations has led to changes in this genus’ taxonomic classification. Although the impact of the new species on clinical presentation and treatment remains unclear, they can influence diagnosis when serological methods are employed. Further, although the infection is usually acquired in rural areas, the symptoms may manifest years or decades later when the patient might be living in the city or even in another country outside the endemic region. Brazil accounts for 80% of PCM cases worldwide, and its incidence is rising in the northern part of the country (Amazon region), owing to new settlements and deforestation, whereas it is decreasing in the south, owing to agriculture mechanization and urbanization. Clusters of the acute/subacute form are also emerging in areas with major human intervention and climate change. Advances in diagnostic methods (molecular and immunological techniques and biomarkers) remain scarce, and even the reference center’s diagnostics are based mainly on direct microscopic examination. Classical imaging findings in the lungs include interstitial bilateral infiltrates, and eventually, enlargement or calcification of adrenals and intraparenchymal central nervous system lesions are also present. Besides itraconazole, cotrimoxazole, and amphotericin B, new azoles may be an alternative when the previous ones are not tolerated, although few studies have investigated their use in treating PCM.

Challenges in Serologic Diagnostics of Neglected Human Systemic Mycoses: An Overview on Characterization of New Targets

Systemic mycoses have been viewed as neglected diseases and they are responsible for deaths and disabilities around the world. Rapid, low-cost, simple, highly-specific and sensitive diagnostic tests are critical components of patient care, disease control and active surveillance. However, the diagnosis of fungal infections represents a great challenge because of the decline in the expertise needed for identifying fungi, and a reduced number of instruments and assays specific to fungal identification. Unfortunately, time of diagnosis is one of the most important risk factors for mortality rates from many of the systemic mycoses. In addition, phenotypic and biochemical identification methods are often time-consuming, which has created an increasing demand for new methods of fungal identification. In this review, we discuss the current context of the diagnosis of the main systemic mycoses and propose alternative approaches for the identification of new targets for fungal pathogens, which can help in the development of new diagnostic tests.

Screening paracoccidioidomycosis by double immunodiffusion test in a referred diagnostic center in Brazilian southeastern: an accessible tool

PURPOSE

This article shows reports of the clinical-epidemiological characteristics and serological screening in patients assisted by a reference center for PCM care, University Hospital Cassiano Antonio Moraes, Federal University of Espirito Santo, Brazil.

METHODS

The patient's sera with PCM were analyzed by DID test at the beginning and the end treatment. Clinical and demographic data were also collected to characterize the sample.

RESULTS

One hundred patients with a suspected diagnosis of PCM were evaluated. Serology by DID test was used as a screen in all patients. The test was positive for 79 patients (72 for Paracoccidioides brasiliensis and 7 for Paracoccidioides lutzii). Serology was negative in 21 sera, although all of them were diagnosed PCM by histopathologic or direct exam. Serological follow-up was performed during the treatment of all patients. After treatment, 58(58%) had negative serology and 33(33%) low levels of antibodies (≤ 1:16).

CONCLUSION

Our results indicate the importance of the DID test for the screening and monitoring of PCM and that the incidence of P. lutzii might be greater than expected in areas where it is not the predominant PCM species. Therefore, this article may contribute to improving the knowledge and clinical management about this disease.

Distinct Pattern of Paracoccidioides lutzii, P. restrepiensis and P. americana Antigens Recognized by IgE in Human Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is caused by the fungi Paracoccidioides spp. The main antigens recognized by IgE are known for P. brasiliensis species complex, but not for P. lutzii. Current research investigated the major P. lutzii (LDR2) antigens recognized by IgE, in comparison to P. restrepiensis and P. americana (former P. brasiliensis species complex), besides IgG recognition. Cell-free antigens (CFA) from P. lutzii (LDR2), P. restrepiensis (B339) and P. americana (LDR3) were analyzed by ELISA and immunoblotting (IB) by detecting specific IgG and IgE from sera from patients with PCM presumable by P. brasiliensis species complex (n = 24). Additionally, somatic antigen (SA) was analyzed by IB. P. lutzii (LDR2) antigens showed significantly lower reactivity than P. restrepiensis (B339) and P. americana (LDR3) in ELISA for both IgE and IgG (p < 0.05). The IgE-IB pattern was different between P. lutzii (LDR2) and the other species, regarding components with ~30 kDa and ~70 kDa in CFA and a ~200 kDa in SA. P. lutzii (LDR2) present at least three antigens recognized by IgE which mainly differ from P. restrepiensis (B339) and, to a lesser extent, from P. americana (LDR3). Current research evidenced for the first time the major P. lutzii (LDR2) antigens recognized by IgE.

An update on the occurrence of Paracoccidioides species in the Midwest region, Brazil: Molecular epidemiology, clinical aspects and serological profile of patients from Mato Grosso do Sul State

BACKGROUND

Paracoccidioidomycosis (PCM) is a systemic and endemic fungal infection in Latin American, mainly in Brazil. The majority of PCM cases occur in large areas in Brazil, comprising the South, Southeast and Midwest regions, with the latter demonstrating a higher incidence of the species Paracoccidioides lutzii.

METHODOLOGY AND MAIN FINDINGS

This study presents clinical, molecular and serological data of thirteen new PCM cases during 2016 to 2019 from the state of Mato Grosso do Sul, located in the Midwest region, Brazil. From these thirteen cases, sixteen clinical isolates were obtained and their genomic DNAs were subjected to genotyping by tub1 -PCR-RFLP. Results showed Paracoccidioides brasiliensis sensu stricto (S1) (11/16; 68.8%), Paracoccidioides restrepiensis (PS3) (4/16; 25.0%) and P. lutzii (1/16; 6.2%) as Paracoccidiodes species. Therefore, in order to understand whether the type of phylogenetic species that are circulating in the state influence the reactivity profile of serological tests, we performed double agar gel immunodiffusion (DID), using exoantigens from genotyped strains found in this series of PCM cases. Overall, our DID tests have been false negative in about 30% of confirmed PCM cases. All patients were male, most with current or previous rural activity, with ages ranging from 17 to 59 years, with 11 patients (84.6%) over 40 years of age. No clinical or epidemiological differences were found between Paracoccidioides species. However, it is important to note that the only case of P. lutzii died as an outcome.

CONCLUSIONS

This study suggests P. brasiliensis sensu stricto (S1) as the predominant species, showing its wide geographic distribution in Brazil. Furthermore, our findings revealed, for the first time, the occurrence of P. restrepiensis (PS3) in the state of Mato Grosso do Sul, Brazil. Despite our setbacks, it would be interesting to provide the complete sequencing of these clinical isolates to complement the molecular information presented.

IgG reactivity profile to Paracoccidioides spp. antigens in people with asymptomatic Paracoccidioidomycosis

Introduction. Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides spp. As the disease is known to affect mostly men over 40 years old who previously worked handling soil, some cities of agricultural economy in endemic regions may have more cases of paracoccidioidal infection.Gap statement. The true frequency of PCM cannot be established in Brazil because it is not a disease of mandatory reporting. The detection of paracoccidioidal infection may assist in the planning of health services, in order to provide early detection of the disease and to prevent its worsening or even progression to death. In addition, little is described about sera reactivity with antigens from different species of Paracoccidiodes, especially P. lutzii.Aim. Current research was conducted in an inland municipality of southern Brazil, in order to assess infection rate within this endemic region of PCM disease.Methodology. ELISA was employed to evaluate 359 sera from random volunteers from Guarapuava, Paraná, Brazil, to detect IgG against cell-free antigens (CFA) from P. restrepiensis B339, P. americana LDR3 and P. lutzii LDR2. Confirmatory ELISA employed gp43 from B339. Reduction of cross-reactions was sought by treatment with sodium metaperiodate (SMP-CFA, SMP-gp43). Immunoblot was performed with 37 selected sera among those reactive in ELISA. Epidemiological profile was assessed by questionnaire.Results. ELISA reactivity was: CFA/SMP-CFA in general 37.3/17.8 %, B339 25.3/14.5 %, LDR3 24.5/1.4 %, LDR2 8.3/5.8 %; gp43/SMP-gp43 7.2/4.7 %. There were sera reactive with multiple CFAs. In immunoblot, five sera showed the same reaction profile with P. lutzii's antigens as PCM disease sera. Rural residence and soil-related professions were risk factors for paracoccidioidal infection.Conclusion. The low prevalence is in accordance with previous reports of lower PCM disease endemicity in Guarapuava than in other areas of Paraná. Although P. brasiliensis seems to be the prevalent strain of the region, 21 sera from people who only lived in Guarapuava reacted with P. lutzii LDR2. CFA-ELISA with whole antigens seems a good option for serological screening in epidemiological surveys.

Immunoproteomic Analysis Reveals Novel Candidate Antigens for the Diagnosis of Paracoccidioidomycosis Due to Paracoccidioides lutzii

Paracoccidioidomycosis (PCM) is a life-threatening systemic infection caused by the fungal pathogen Paracoccidioides brasiliensis and related species. Whole-genome sequencing and stage-specific proteomic analysis of Paracoccidioides offer the opportunity to profile humoral immune responses against P. lutzii and P. brasiliensis s. str. infection using innovative screening approaches. Here, an immunoproteomic approach was used to identify PCM-associated antigens that elicit immune responses by combining 2-D electrophoresis of P. lutzii and P. brasiliensis proteomes, immunological detection using a gold-standard serum, and mass spectrometry analysis. A total of 16 and 25 highly immunoreactive proteins were identified in P. lutzii and P. brasiliensis, respectively, and 29 were shown to be the novel antigens for Paracoccidioides species, including seven uncharacterized proteins. Among the panel of proteins identified, most are involved in metabolic pathways, carbon metabolism, and biosynthesis of secondary metabolites in both immunoproteomes. Remarkably, six isoforms of the surface-associated enolase in the range of 54 kDa were identified as the major antigens in human PCM due to P. lutzii. These novel immunoproteomes of Paracoccidioides will be employed to develop a sensitive and affordable point-of-care diagnostic assay and an effective vaccine to identify infected hosts and prevent infection and development of human PCM. These findings provide a unique opportunity for the refinement of diagnostic tools of this important neglected systemic mycosis, which is usually associated with poverty.

Exoantigens of Paracoccidioides spp. Promote Proliferation and Modulation of Human and Mouse Pulmonary Fibroblasts

Paracoccidioidomycosis (PCM) is a systemic granulomatous fungal infection caused by thermally dimorphic fungi of the genus Paracoccidioides. Endemic in Latin America, PCM presents with high incidence in Brazil, Colombia, and Venezuela, especially among rural workers. The main clinical types are acute/subacute (AF) form and chronic form (CF). Even after effective antifungal treatment, patients with CF usually present sequelae, such as pulmonary fibrosis. In general, pulmonary fibrosis is associated with dysregulation wound healing and abnormal fibroblast activation. Although fibrogenesis is recognized as an early process in PCM, its mechanisms remain unknown. In the current study, we addressed the role of Paracoccidioides spp. exoantigens in pulmonary fibroblast proliferation and responsiveness. Human pulmonary fibroblasts (MRC-5) and pulmonary fibroblasts isolated from BALB/c mice were cultivated with 2.5, 5, 10, 100, and 250 µg/ml of exoantigens produced from P. brasiliensis (Pb18 and Pb326) and P. lutzii (Pb01, Pb8334, and Pb66) isolates. Purified gp43, the immunodominant protein of P. brasiliensis exoantigens, was also evaluated at concentrations of 5 and 10 µg/ml. After 24 h, proliferation and production of cytokines and growth factors by pulmonary fibroblasts were evaluated. Each exoantigen concentration promoted a different level of interference of the pulmonary fibroblasts. In general, exoantigens induced significant proliferation of both murine and human pulmonary fibroblasts (p < 0.05). All concentrations of exoantigens promoted decreased levels of IL-6 (p < 0.05) and VEGF (p < 0.05) in murine fibroblasts. Interestingly, decreased levels of bFGF (p < 0.05) and increased levels of TGF-β1 (p < 0.05) and pro-collagen I (p < 0.05) were observed in human fibroblasts. The gp43 protein induced increased TGF-β1 production by human cells (p = 0.02). In conclusion, our findings showed for the first time that components of P. brasiliensis and P. lutzii interfered in fibrogenesis by directly acting on the biology of pulmonary fibroblasts.

Characterization of a Paracoccidioides spp. strain from southeastern Brazil genotyped as Paracoccidioides restrepiensis (PS3) and review of this phylogenetic species

Phylogenetic species of Paracoccidioides brasiliensis complex (S1a and S1b, PS2, PS3, and PS4) and Paracoccidioides lutzii are agents of paracoccidioidomycosis, an endemic fungal disease in Latin America. P. restrepiensis (PS3 genotype) was classified as monophyletic and geographically restricted to Colombia and neighboring territories. BAT (or Pb-327B) was isolated from a patient living in the southeast region of Brazil but with genotype similar to Colombian Paracoccidioides spp. strains. This study aimed to define the phylogenetic species of BAT isolate by using additional genotyping methods, as well as reviewing the epidemiological and clinical studies related to P. restrepiensis isolates. Genomic DNA of BAT isolate and reference strains of P. brasiliensis sensu stricto (S1b), P. americana (PS2), P. restrepiensis (PS3), and P. lutzii were analyzed by conventional polymerase chain reaction (PCR) of partial gp43 exon 2 loci, by PCR-RFLP technique of tub1 gene, and by sequencing of the whole gp43 exon 2 loci. Here, we show that BAT isolate belongs to P. restrepiensis species, which is an unusual identification in southeastern Brazil, where P. brasiliensis sensu stricto is the prevalent genotype. This identification has relevance for geographical distribution and propagation of the genus Paracoccidioides in South America.

Proteomic analysis of Paracoccidioides brasiliensis complex isolates: Correlation of the levels of differentially expressed proteins with in vivo virulence

BACKGROUND

Paracoccidioidomycosis (PCM) is a systemic mycosis commonly found in Latin America that is caused by distinct species of Paracoccidioides genus: Paracoccidioides brasiliensis complex (S1, PS2, PS3 and PS4) and Paracoccidioides lutzii. Its pathobiology has been recently explored by different approaches to clarify the mechanisms of host-pathogen interactions underpinning PCM. The diversity of clinical forms of this disease has been attributed to both host- and fungus-related factors.

METHODOLOGY/PRINCIPAL FINDINGS

For better understanding of the molecular underpinnings of host-fungus interactions, we evaluated in vivo virulence of nine Paracoccidioides brasiliensis complex isolates and correlated it to protein expression profiles obtained by two-dimensional gel electrophoresis. Based on the recovery of viable fungi from mouse organs, the isolates were classified as those having low, moderate, or high virulence. Highly virulent isolates overexpressed proteins related to adhesion process and stress response, probably indicating important roles of those fungal proteins in regulating the colonization capacity, survival, and ability to escape host immune system reaction. Moreover, highly virulent isolates exhibited enhanced expression of glycolytic pathway enzymes concomitantly with repressed expression of succinyl-CoA ligase beta chain, a protein related to the tricarboxylic acid cycle.

CONCLUSIONS/SIGNIFICANCE

Our findings may point to the mechanisms used by highly virulent P. brasiliensis isolates to withstand host immune reactions and to adapt to transient iron availability as strategies to survive and overcome stress conditions inside the host.

Ceruloplasmin, transferrin and apolipoprotein A-II play important role in treatment's follow-up of paracoccidioidomycosis patients

Paracoccidioidomycosis (PCM) is a systemic disease caused by thermodymorphic fungi of the Paracoccidioides brasiliensis complex, (Paracoccidioides spp.). Patients with PCM reveal specific cellular immune impairment. Despite the effective treatment, quiescent fungi can lead to relapse, usually late, the serological diagnosis of which has been deficient. The present study was carried out with the objective of investigating a biomarker for the identification of PCM relapse and another molecule behaving as an immunological recovery biomarker; therefore, it may be used as a cure criterion. In the evolutionary analysis of the proteins identified in PCM patients, comparing those that presented with those that did not reveal relapse, 29 proteins were identified. The interactions observed between the proteins, using transferrin and haptoglobin, as the main binding protein, were strong with all the others. Patient follow-up suggests that cerulosplamin may be a marker of relapse and that transferrin and apolipoprotein A-II may contribute to the evaluation of the treatment efficacy and avoiding a premature decision.

Serological proteomic biomarkers to identify Paracoccidioides species and risk of relapse

The sensitivity of the double agar gel immunodiffusion test is about 90% in patients with untreated paracoccidioidomycosis (PCM), but it is much lower in cases of relapse. In addition, serum from patients with PCM caused by Paracoccidioides lutzii, frequent in the Midwest region of Brazil, do not react with the classical antigen obtained from Pb B-339. These findings showed the need for alternative diagnostic methods, such as biological markers through proteomics. The aim of this study was to identify biomarkers for the safe identification of PCM relapse and specific proteins that could distinguish infections caused by Paracoccidioides brasiliensis from those produced by Paracoccidioides lutzii. Proteomic analysis was performed in serum from 9 patients with PCM caused by P. brasiliensis, with and without relapse, from 4 patients with PCM produced by P. lutzii, and from 3 healthy controls. The comparative evaluation of the 29 identified plasma proteins suggested that the presence of the immunoglobulin (Ig) alpha-2 chain C region and the absence of Ig heavy chain V-III TIL indicate infection by P. lutzii. In addition, the absence of complement factor B protein might be a predictor of relapse. The evaluation of these proteins in a higher number of patients should be carried out in order to validate these findings.

Brazilian guidelines for the clinical management of paracoccidioidomycosis

Paracoccidioidomycosis is a systemic fungal disease occurring in Latin America that is associated with rural environments and agricultural activities. However, the incidence and prevalence of paracoccidiodomycosis is underestimated because of the lack of compulsory notification. If paracoccidiodomycosis is not diagnosed and treated early and adequately, the endemic fungal infection could result in serious sequelae. While the Paracoccidioides brasiliensis ( P. brasiliensis ) complex has been known to be the causal agent of paracoccidiodomycosis, a new species, Paracoccidioides lutzii ( P. lutzii ), has been reported in Rondônia, where the disease has reached epidemic levels, and in the Central West and Pará. Accurate diagnoses and availability of antigens that are reactive with the patients' sera remain significant challenges. Therefore, the present guidelines aims to update the first Brazilian consensus on paracoccidioidomycosis by providing evidence-based recommendations for bedside patient management. This consensus summarizes etiological, ecoepidemiological, molecular epidemiological, and immunopathological data, with emphasis on clinical, microbiological, and serological diagnosis and management of clinical forms and sequelae, as well as in patients with comorbidities and immunosuppression. The consensus also includes discussion of outpatient treatments, severe disease forms, disease prevalence among special populations and resource-poor settings, a brief review of prevention and control measures, current challenges and recommendations.

Paracoccidioidomycosis infection in domestic and wild mammals by Paracoccidioides lutzii

Paracoccidioidomycosis (PCM) is a systemic mycosis that occurs in several Latin American countries, especially in Brazil. It is caused by the thermo-dimorphic fungus Paracoccidioides spp. Serological studies to detect animal infection represent an excellent strategy for data on the agent's ecology. Although the state of Rio Grande do Sul (RS) is an endemic area for PCM in humans, there is scarce information available on the ecology of the agent in the region. This study aimed to investigate the infection by Paracoccidioides lutzii in animals living in RS, Brazil. A total of 85 wild mammals, 200 horses and 196 domestic dogs, previously tested for infection by P. brasiliensis, were included in this study. Serum samples from the animals were tested by ELISA to detect anti- P. lutzii antibodies. From the 481 animals tested, 105 (21.8%) were seropositive for IgG anti-P. lutzii. Of these, 54 were also positive for P. brasiliensis. A total of 11 horses (10.5%), 30 dogs (28.8%) and 10 wild mammals (9.5%) were positive only for P. lutzii (n=51). The detection of anti-P. lutzii antibodies in animals of RS suggests that the fungus can be found in southern Brazil, despite being described mainly in the midwest and southeast of the country.

Advances and challenges in paracoccidioidomycosis serology caused by Paracoccidioides species complex: an update

Understanding the possible methodologies for the rapid and inexpensive identification of fungal infections is essential for disease diagnosis, but there are some limitations. To help with this problem, serological methods that detect antigens or antibodies are widely used and are useful for the diagnosis of paracoccidioidomycosis (PCM) through the detection of gp43, which is the main antigen employed for the immunodiagnosis of this disease caused by Paracoccidioides brasiliensis. However, the use of gp43 has become restricted because it was recently found that this marker is not identified in the infections caused by Paracoccidioides lutzii. Therefore, it is necessary to identify new antigens in both species or antigens specific for P. lutzii to decrease the morbidity and/or mortality associated with PCM. This review provides a discussion of new diagnostic challenges after the recent discoveries regarding the taxonomy of the Paracoccidioides genus.

Immunodiagnosis of paracoccidioidomycosis due to Paracoccidioides brasiliensis using a latex test: detection of specific antibody anti-gp43 and specific antigen gp43

BACKGROUND

Paracoccidioidomycosis (PCM) is a life-threatening systemic disease and is a neglected public health problem in many endemic regions of Latin America. Though several diagnostic methods are available, almost all of them present with some limitations.

METHOD/PRINCIPLE FINDINGS

A latex immunoassay using sensitized latex particles (SLPs) with gp43 antigen, the immunodominant antigen of Paracoccidioides brasiliensis, or the monoclonal antibody mAb17c (anti-gp43) was evaluated for antibody or antigen detection in sera, cerebrospinal fluid (CSF), and bronchoalveolar lavage (BAL) from patients with PCM due to P. brasiliensis. The gp43-SLPs performed optimally to detect specific antibodies with high levels of sensitivity (98.46%, 95% CI 91.7-100.0), specificity (93.94%, 95% CI 87.3-97.7), and positive (91.4%) and negative (98.9%) predictive values. In addition, we propose the use of mAb17c-SLPs to detect circulating gp43, which would be particularly important in patients with immune deficiencies who fail to produce normal levels of immunoglobulins, achieving good levels of sensitivity (96.92%, 95% CI 89.3-99.6), specificity (88.89%, 95% CI 81.0-94.3), and positive (85.1%) and negative (97.8%) predictive values. Very good agreement between latex tests and double immune diffusion was observed for gp43-SLPs (k = 0.924) and mAb17c-SLPs (k = 0.850), which reinforces the usefulness of our tests for the rapid diagnosis of PCM in less than 10 minutes. Minor cross-reactivity occurred with sera from patients with other fungal infections. We successfully detected antigens and antibodies from CSF and BAL samples. In addition, the latex test was useful for monitoring PCM patients receiving therapy.

CONCLUSIONS/SIGNIFICANCE

The high diagnostic accuracy, low cost, reduced assay time, and simplicity of this new latex test offer the potential to be commercialized and makes it an attractive diagnostic assay for use not only in clinics and medical mycology laboratories, but mainly in remote locations with limited laboratory infrastructure and/or minimally trained community health workers.

Serology of paracoccidioidomycosis due to Paracoccidioides lutzii

Paracoccidioides lutzii is a new agent of paracoccidioidomycosis (PCM) and has its epicenter localized to the Central-West region of Brazil. Serological diagnosis of PCM caused by P. lutzii has not been established. This study aimed to develop new antigenic preparations from P. lutzii and to apply them in serological techniques to improve the diagnosis of PCM due to P. lutzii. Paracoccidioides lutzii exoantigens, cell free antigen (CFA), and a TCA-precipitated antigen were evaluated in immunodiffusion (ID) tests using a total of 89 patient sera from the Central-West region of Brazil. Seventy-two sera were defined as reactive for P. brasiliensis using traditional antigens (AgPbB339 and gp43). Non-reactive sera for traditional antigens (n = 17) were tested with different P. lutzii preparations and P. lutzii CFA showed 100% reactivity. ELISA was found to be a very useful test to titer anti-P. lutzii antibodies using P. lutzii-CFA preparations. Sera from patients with PCM due to P. lutzii presented with higher antibody titers than PCM due to P. brasiliensis and heterologous sera. In western blot, sera from patients with PCM due to P. lutzii were able to recognize antigenic molecules from the P. lutzii-CFA antigen, but sera from patients with PCM due to P. brasiliensis could not recognize any P. lutzii molecules. Due to the facility of preparing P. lutzii CFA antigens we recommend its use in immunodiffusion tests for the diagnosis of PCM due to P. lutzii. ELISA and western blot can be used as complementary tests.

Fatal fungemia due to Paracoccidioides lutzii

We report the first case of fungemia caused by Paracoccidioides lutzii in a 51-year-old male farm worker from the central-west region of Brazil. The fungus was isolated from blood cultures and the species was confirmed by phylogenetic identification. Despite specific treatment and intensive care, the patient died 39 days after admission.

Serological and antigenic profiles of clinical isolates of Paracoccidioides spp. from Central Western Brazil

Clinical Paracoccidioides spp. isolates from patients with paracoccidioidomycosis (PCM) in Mato Grosso, Brazil exhibit different patterns of serologic reactivity. The results observed for reactions of radial immunodiffusion against the commonly used exoantigens containing a 43-kDa glycoprotein (gp43) suggest that this fungus exhibits major antigenic variability by geographic region. There is a phylogenetic gap between Paracoccidioides spp. isolates among different regions of Latin America. In particular, those from the central region of Brazil (i.e. Mato Grosso state) exhibit a lower rate of genetic similarity. We aimed at investigating the phylogenetic classification of clinical isolates of Paracoccidioides spp. in Central Brazil and the different antigenic profiles that produce. Exoantigens were obtained from five clinical isolates: two P. brasiliensis (Pb166 and Pb2880) and three P. lutzii (PL2875, PL9840, and PL2912). The protein/glycoprotein profiles of P. lutzii exoantigens were different from each other. Isolate PL9840 exhibited the most distinct bands, and isolates PL2875 and PL2912 exhibited more diffuse bands and a very intense band between 50 and 60 kDa. P. brasiliensis isolates had similar protein profiles, exhibiting a low-intensity band at 220 kDa and a diffuse band between 50 and 60 kDa. P. lutzii isolates exhibit high species-specific antigen variability, which we have already been assessed in proteomic studies.

Inhibition of PbGP43 expression may suggest that gp43 is a virulence factor in Paracoccidioides brasiliensis

Glycoprotein gp43 is an immunodominant diagnostic antigen for paracoccidioidomycosis caused by Paracoccidioides brasiliensis. It is abundantly secreted in isolates such as Pb339. It is structurally related to beta-1,3-exoglucanases, however inactive. Its function in fungal biology is unknown, but it elicits humoral, innate and protective cellular immune responses; it binds to extracellular matrix-associated proteins. In this study we applied an antisense RNA (aRNA) technology and Agrobacterium tumefaciens-mediated transformation to generate mitotically stable PbGP43 mutants (PbGP43 aRNA) derived from wild type Pb339 to study its role in P. brasiliensis biology and during infection. Control PbEV was transformed with empty vector. Growth curve, cell vitality and morphology of PbGP43 aRNA mutants were indistinguishable from those of controls. PbGP43 expression was reduced 80–85% in mutants 1 and 2, as determined by real time PCR, correlating with a massive decrease in gp43 expression. This was shown by immunoblotting of culture supernatants revealed with anti-gp43 mouse monoclonal and rabbit polyclonal antibodies, and also by affinity-ligand assays of extracellular molecules with laminin and fibronectin. In vitro, there was significantly increased TNF-α production and reduced yeast recovery when PbGP43 aRNA1 was exposed to IFN-γ-stimulated macrophages, suggesting reduced binding/uptake and/or increased killing. In vivo, fungal burden in lungs of BALB/c mice infected with silenced mutant was negligible and associated with decreased lung ΙΛ−10 and IL-6. Therefore, our results correlated low gp43 expression with lower pathogenicity in mice, but that will be definitely proven when PbGP43 knockouts become available. This is the first study of gp43 using genetically modified P. brasiliensis.

Occurrence of Paracoccidioides lutzii in the Amazon region: description of two cases

Paracoccidioidomycosis (PCM), the most important human systemic mycosis in Latin America, is known to be caused by at least four different phylogenetic lineages within the Paracoccidioides brasiliensis complex, including S1, PS2, PS3, and Pb01-like group. Herein, we describe two cases of PCM in patients native from the Amazon region. The disease was originally thought to have been caused by P. brasiliensis. Despite the severity of the cases, sera from the patients were negative in immunodiffusion tests using the standard exoantigen from P. brasiliensis B-339. However, a positive response was recorded with an autologous preparation of Paracoccidioides lutzii exoantigen. A phylogenetic approach based on the gp43 and ARF loci revealed high similarity between our clinical isolates and the Pb01-like group. The occurrence of PCM caused by P. lutzii in the Brazilian Amazon (Pará State) was thus proven. The incidence of PCM caused by P. lutzii may be underestimated in northern Brazil.

Effects of pretreating serum samples on the performance of a latex agglutination test for serodiagnosis of paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is a fungal disease caused by Paracoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of budding P. brasiliensis yeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the "gold standard" test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM.

Differential PbP27 expression in the yeast and mycelial forms of the Paracoccidioides brasiliensis species complex

p27 is an antigenic protein produced by Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis (PCM). Despite its unknown function, it has been suggested as a putative virulence factor, proposed as a suitable target for the design of diagnostic tools and vaccines, and considered as an enhancer in antifungal treatment of PCM. We evaluated sequence polymorphisms of PbP27 gene sequence among isolates, finding some polymorphisms associated with the isolates' phylogenetic origin. In order to determine if there was a differential expression pattern between morphological states and among isolates, we also evaluated PbP27 expression, at transcriptional and translational levels, in mycelia and yeast cultures in 14 isolates belonging to the P. brasiliensis species complex (S1, PS2, PS3, and "Pb01-like", proposed to be named Paracoccidioides lutzii) by two techniques, real time RT-PCR (RT-qPCR) and protein dot blot. For the latter, four protein extracts from different cell localizations (SDS or β-mercaptoethanol, cytoplasmic and extracellular proteins) were analyzed for each isolate. p27 was present in the four extracts evaluated, mainly in the SDS extract, corresponding to an extract containing proteins loosely attached to the cell wall. This information correlates with immunohistochemical analysis, where positive staining of the yeasts' cell wall was observed. We found that p27 was present in all isolates, mainly in the yeast form. This pattern was corroborated by RT-qPCR results, with higher expression levels found in the yeast form for most of the isolates. The results provide new insights into the expression patterns of this protein, and further characterize it in view of potential uses as a diagnostic and/or therapeutic tool.

Development and evaluation of a latex agglutination test for the serodiagnosis of paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Latin America. It is caused by the dimorphic fungus Paracoccidioides brasiliensis. The immunodiffusion (ID) test is one of the most widely used techniques for PCM serologic diagnosis due to the simplicity and low costs of its execution. However, it requires trained and qualified people to execute it. The purpose of this study was to evaluate a latex particle agglutination (LA) test for the detection of anti-P. brasiliensis antibodies by using pooled crude exoantigens from the fungus. Fifty-one serum samples obtained from patients with PCM were tested. Positivity was observed in 84% (43/51) of these patients, and the agglutination patterns varied from small clumps with a cloudy background to large clumps with a clear background. The antibody titer reactivity ranged from 1:2 to 1:64. Cross-reactivity was observed in sera from patients with aspergillosis, histoplasmosis, and nonfungal disease. Serum samples obtained from healthy donors were not reactive. The sensitivity and specificity of the LA test were 84% and 81%, respectively. When comparing the LA test with the double-immunodiffusion test, we found an agreement of 92%. Further work is needed to improve the performance of the LA assay before it can be proposed as a reliable diagnostic tool, mainly in laboratories with little infrastructure.

Serodiagnosis of sporotrichosis infection in cats by enzyme-linked immunosorbent assay using a specific antigen, SsCBF, and crude exoantigens

The main objective of this study is to standardize an ELISA for the diagnosis of feline sporotrichosis. Sporothrix schenckii is the etiological agent of human and animal sporotrichosis. Cats may act as reservoirs for S. schenckii and can transmit the infection to humans by a bite or scratch. There are few methods for the serological diagnosis of fungal diseases in animals. In this paper, an ELISA test for the diagnosis of cat sporotrichosis is proposed, which detects S. schenckii-specific antibodies in feline sera. Two different kinds of antigens were used: "SsCBF", a specific molecule from S. schenckii that consists of a Con A-binding fraction derived from a peptido-rhamnomannan component of the cell wall, and a S. schenckii crude exoantigen preparation. The ELISA was developed, optimized, and evaluated using sera from 30 cats with proven sporotrichosis (by culture isolation); 22 sera from healthy feral cats from a zoonosis center were used as negative controls. SsCBF showed 90% sensitivity and 96% specificity in ELISA; while crude exoantigens demonstrated 96% sensitivity and 98% specificity. The ELISA assay described here would be a valuable screening tool for the detection of specific S. schenckii antibodies in cats with sporotrichosis. The assay is inexpensive, quick to perform, easy to interpret, and permits the diagnosis of feline sporotrichosis.

Characteristics of environmental Paracoccidioides brasiliensis isolates

The ecological niche or exact habitat of the fungus Paracoccidioides brasiliensis is not known, and few isolates have been obtained from the environment. In this study, ten isolates were analyzed with respect to antigenic composition, serology, pathogenicity, and molecular aspects. Gp43 is considered to be the molecular basis for the serodiagnosis of paracoccidioidomycosis; however, in this study only six of the environmental isolates secreted this molecule (four in great amounts and two in small amounts). Other molecules were also produced. When exoantigens from these isolates were tested using immunodiffusion, only four preparations were positive by ID tests. However, when these exoantigens were tested by ELISA, all of them except one were able to detect anti-P. brasiliensis antibodies. In Western blot assays, these exoantigens showed different reactivities. Isolates that secreted gp43 presented positive reactions for this molecule, and isolates that did not secrete gp43 gave positive reactions for other minor molecules. RAPD analysis revealed that there is great genetic variation between these environmental isolates. These isolates were non-pathogenic: no mortality was observed among the inoculated mice during an 18-month follow-up period.

New approach for diagnosis of candidemia based on detection of a 65-kilodalton antigen

Nosocomial candidiasis is a major concern in tertiary care hospitals worldwide. This infection generally occurs in patients with degenerative and neoplastic diseases and is considered the fourth most frequent cause of bloodstream infections. Diagnosis of candidemia or hematogenous candidiasis has been problematic because clinical signs and symptoms are nonspecific, leading to delays in diagnosis and, consequently, delays in appropriate antifungal therapy. We developed an inhibition enzyme-linked immunosorbent assay (ELISA) for detection of a 65-kDa antigen in an experimental model of candidemia and for diagnosis of patients in intensive care units (ICUs) with suspected candidemia. An anti-65-kDa monoclonal antibody was tested for detection of the 65-kDa antigen produced by Candida albicans, Candida tropicalis, and Candida parapsilosis in murine candidemia models. The 65-kDa antigen was detected in sera at concentrations ranging from 0.012 to 3.25 microg/ml. A total of 20 human patients with candidemia were then evaluated with the inhibition ELISA using sequential sera. Sixteen (80%) patients had the 65-kDa antigen in concentrations ranging from 0.07 to 5.0 microg/ml. Sequential sera from patients with candidemia presented three different patterns of antigenemia of the 65-kDa molecule: (i) total clearance of antigenemia, (ii) initial clearance and relapse of antigenemia, and (iii) partial clearance of antigenemia. Our results indicate detection of the 65-kDa protein may be a valuable tool for the diagnosis of candidemia by C. albicans, C. tropicalis, and C. parapsilosis.

Excretion-secretion products and proteases from live Sporothrix schenckii yeast phase: immunological detection and cleavage of human IgG

Antigenic preparations from Sporothrix schenckii usually involve materials from mixed cultures of yeast and mycelia presenting cross-reactions with other deep mycoses. We have standardized pure yeast phase with high viability of the cells suitable to obtain specific excretion-secretion products without somatic contaminations. These excretion-secretion products were highly immunogenic and did not produce noticeable cross-reactions in either double immunodiffusion or Western blot. The antigenic preparation consists mainly of proteins with molecular weights between 40 and 70 kDa, some of them with proteolytic activity in mild acidic conditions. We also observed cathepsin-like activity at two days of culture and chymotrypsin-like activity at four days of culture consistent with the change in concentration of different secreted proteins. The proteases were able to cleave different subclasses of human IgG suggesting a sequential production of antigens and molecules that could interact and interfere with the immune response of the host.

Coccidioidal pericarditis: a rapid presumptive diagnosis by an in-house antigen confirmed by mycological and molecular methods

Coccidioidal pericarditis is a condition found in approximately 1-5% of patients infected by Coccidioides species. It is associated with widely diverse clinical symptoms. This paper reports a case of coccidioidal pericarditis diagnosed by an in-house Coccidioides posadasii antigen and confirmed with mycological and molecular methods. From February to September 2005, the patient suffered from fever, weight loss, a non-productive cough, thoracic pain and tachycardia. He received a positive diagnosis of coccidioidal pericarditis only in October 2005. The macromorphological examination of the culture showed a whitish felt-like colony, which became brownish with age. Preparations in lactophenol cotton blue stain showed hyaline septate hyphae with fragmentation and thin arthroconidia-like structures. Pericardial fluid and sera samples were positive for Coccidioides antibodies by immunodiffusion and ELISA with a C. posadasii in-house antigen preparation. The C. posadasii identification was confirmed by nested PCR of the antigen 2/proline-rich antigen (Ag2/PRA) encoding gene.

Diagnosis of Paracoccidioidomycosis by detection of antigen and antibody in bronchoalveolar lavage fluids

Paracoccidioidomycosis (PCM) is a systemic infection caused by the fungus Paracoccidioides brasiliensis and is believed to be the leading cause of fungal pulmonary infection. In this study, we used an inhibition enzyme-linked immunosorbent assay to diagnose pulmonary PCM based on the detection of 43-kDa and 70-kDa molecules in bronchoalveolar lavage fluids. The results were compared with results obtained by classical methods for antibody detection.

Diagnosis of neuroparacoccidioidomycosis by detection of circulating antigen and antibody in cerebrospinal fluid

Neuroparacoccidioidomycosis (neuroPCM) is the central nervous system infection by the fungus Paracoccidioides brasiliensis. Its diagnosis is a difficult task that depends on neuroimaging techniques such as computed tomography and magnetic resonance imaging. However, the detection of circulating P. brasiliensis antigens in body fluids by inhibition enzyme-linked immunosorbent assay (inh-ELISA) has provided encouraging results. In this study, 14 cerebrospinal fluid (CSF) and 11 serum samples of patients with neuroPCM were analyzed by inh-ELISA for detection of circulating glycoprotein antigens of 43 kDa (gp43) and 70 kDa (gp70). Circulating gp43 and gp70 antigens were detected in all CSF samples from patients with neuroPCM at mean concentrations of 19.3 and 6.8 mug/ml, respectively. In addition, both gp43 and gp70 antigens were detected in 10 of 11 serum samples analyzed at mean concentrations of 4.6 and 4.0 mug/ml, respectively. By immunodiffusion test, CSF samples were determined to be negative in 13 of 14 samples. The detection of anti-gp43 and anti-gp70 antibodies by conventional ELISA showed positive results for all CSF samples, with titers ranging from 1:50 to 1:51,200. Therefore, the high sensitivity of the inh-ELISA technique in detecting gp43 and gp70 antigens in the CSF of neuroPCM patients strongly indicates that this assay can be considered as a powerful diagnostic tool. In addition, the finding of anti-gp43 and anti-gp70 antibodies in CSF samples by conventional ELISA also seems to be a promising diagnostic method for this special modality of PCM.

Improvement of the specificity of an enzyme-linked immunosorbent assay for diagnosis of paracoccidioidomycosis

In an attempt to improve the specificity of an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of paracoccidioidomycosis (PCM), sera from patients with PCM were tested using various approaches, such as sodium metaperiodate antigen (gp43) treatment, a serum absorption process with Candida albicans or Histoplasma capsulatum antigens, and dilution of serum in galactose, the main common epitope among pathogenic fungi. The maximum specificity found in this ELISA was 84%. All of these procedures proved inefficient for eliminating all cross-reacting antibodies and obtaining an ELISA specific for PCM diagnosis.

Variable gp43 secretion by Paracoccidioides brasiliensis clones obtained by two different culture methods

The main objectives of this study were to obtain clones of Paracoccidioides brasiliensis by two methods (micromanipulation and plating assay) and to determine if the secretion of the 43-kDa glycoprotein (gp43) is dependent on the clonal culture. The results show that the secretion of gp43 is not dependent on clonal cultures. Clones that originally were secretors of this molecule, after subculturing, lost this characteristic; on the other hand, clones that originally did not secrete gp43 began to secrete gp43 after subculturing.

Development of an enzyme-linked immunosorbent assay for the serodiagnosis of several clinical forms of sporotrichosis

We performed a serological study with sera from 92 patients with confirmed sporotrichosis registered between 1999 and 2004 in two hospitals in Rio de Janeiro State, Brazil. The clinical presentation of sporotrichosis was distributed as follows: lymphocutaneous, 67%; fixed cutaneous, 23%; disseminated cutaneous, 8%; and extracutaneous, 2%. Sera were assayed by ELISA against a cell wall antigen of Sporothrix schenckii, SsCBF, that we have previously described. The cross-reactivity was determined with 77 heterologous sera. The serological test showed a sensitivity of 90% and a global efficiency of 86%. A group of 55 patients with several clinical presentations of sporotrichosis was clinically and serologically followed-up for at least 6 months. We observed by ELISA data a decrease in the antibody serum titers which correlated with the progress in healing. An HIV-positive patient with meningeal sporotrichosis was serologically followed-up for over 2 years. Serum and cerebrospinal fluid specimens were examined and significant antibodies levels against the antigen SsCBF were detected. Our results strongly suggest that this serological test is valuable for the differential diagnosis and follow-up of all clinical forms of sporotrichosis.

Detection of Paracoccidioides brasiliensis gp70 circulating antigen and follow-up of patients undergoing antimycotic therapy

Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Central and South America, is caused by the dimorphic fungus Paracoccidioides brasiliensis and has a high prevalence in Brazil. Glycoproteins of 43 and 70 kDa are the main antigenic compounds of P. brasiliensis and are recognized by Western blotting by 100 and 96% of PCM patient sera, respectively. In the present study, an inhibition enzyme-linked immunosorbent assay (ELISA) was used to detect gp70 in different biological samples from patients with PCM. gp70 was detected in 98.76% of 81 serum samples, with an average concentration of 8.19 microg/ml. The test was positive for 100% of the patients with the acute and chronic unifocal forms of PCM and 98.43% of the patients with the multifocal chronic form, with average concentrations of 11.86, 4.83, and 7.87 microg/ml, respectively. Bronchoalveolar lavage fluid from 23 patients with pulmonary unifocal PCM and 14 samples of cerebrospinal fluid from patients with neurological PCM were also tested for gp70 detection, with the test showing 100% sensitivity and 100% specificity, with mean gp70 concentrations of 7.5 and 6.78 microg/ml, respectively. To investigate the potential of gp70 detection by inhibition ELISA for the follow-up of PCM patients during antimycotic therapy with itraconazole (ITZ), the sera of 23 patients presenting with the chronic multifocal form of PCM were monitored at regular intervals of 1 month for 12 months. The results showed a decrease in circulating gp70 levels during treatment which paralleled the reduction in anti-P. brasiliensis antibody levels. The detection of P. brasiliensis gp70 from the biological fluids of patients suspected of having PCM proved to be a promising method for diagnosing infection and evaluating the efficacy of ITZ treatment.