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32 result(s) for "Paracoccidioides lutzii"
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Paracoccidioides and Paracoccidioidomycosis in the 21st Century
Paracoccidioidomycosis (PCM) defines a broad spectrum of human and animal diseases caused by Paracoccidioides species (Onygenales). In the twenty-first century, Paracoccidioides advanced from a monotypic taxon to a genus that harbors seven species, including P. brasiliensis sensu stricto, P. americana , P. restrepiensis , P. venezuelensis , P. lutzii, P. loboi, and P. cetii . Classic PCM, acquired upon inhalation of propagules from P. brasiliensis sensu stricto, P. americana , P. restrepiensis , P. venezuelensis, and P. lutzii , affects the human lungs and may progress to systemic granulomatous disease with tegumentary and visceral involvement. On the other hand, PCM loboi and PCM ceti caused by the unculturable P. loboi and P. cetii are subcutaneous mycoses, typically observed as keloid lesions in humans and dolphins. Such heterogeneity highlights the importance of recognizing species boundaries in Paracoccidioides to gain insights into the ecology, evolution, clinical features, and mitigation strategies to tackle the advance of PCM.
New Trends in Paracoccidioidomycosis Epidemiology
Paracoccidioidomycosis is a systemic fungal disease occurring in Latin America and more prevalent in South America. The disease is caused by the dimorphic fungus Paracoccidioides spp. whose major hosts are humans and armadillos. The fungus grows in soil and its infection is associated with exposure to the rural environment and to agricultural activities, with a higher risk in coffee and tobacco plantations. Population studies assessing the reactivity to Paracoccidioides spp. antigens by intradermal reaction or serological tests have detected previous subclinical infections in a significant proportion of healthy individuals living in various endemic countries. Paracoccidioidomycosis-disease is manifested by a small minority of infected individuals. The risk of developing the disease and its type of clinical form are related to the personal and life style characteristics of infected individuals, including genetic background, age, sex, ethnicity, smoking habit, alcohol drinking, and eventual cellular immunosuppression. Brazil, Colombia, Venezuela, Argentina, and Ecuador have endemic areas that had already been defined in the 20th century. The incidence of paracoccidioidomycosis can be altered by climate phenomena and mainly by human migration and occupation of poorly explored territories. In Brazil, the endemy tends to expand towards the North and Center-West around the Amazon Region.
Genus Paracoccidioides: Species Recognition and Biogeographic Aspects
Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11-32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides.
Paracoccidioides lutzii Infects Galleria mellonella Employing Formamidase as a Virulence Factor
The formamidase (FMD) enzyme plays an important role in fungal thriving by releasing a secondary nitrogen source as a product of its activity. In Paracoccidioides species, previous studies have demonstrated the upregulation of this enzyme in a wide range of starvation and infective-like conditions. However, Paracoccidioides lutzii formamidase has not yet been defined as a virulence factor. Here, by employing in vivo infections using an fmd -silenced strain in Galleria mellonella larvae model, we demonstrate the influence of formamidase in P . lutzii ’s immune stimulation and pathogenicity. The formamidase silencing resulted in improper arrangement of the nodules, poor melanogenesis and decreased fungal burden. Thus, we suggest that formamidase may be a piece composing the process of molecular recognition by Galleria immune cells. Furthermore, formamidase silencing doubled the observed survival rate of the larvae, demonstrating its importance in fungal virulence in vivo . Therefore, our findings indicate that formamidase contributes to Galleria ’s immune incitement and establishes the role of this enzyme as a P . lutzii virulence factor.
Clinical and epidemiological features of paracoccidioidomycosis due to Paracoccidioides lutzii
The fungus Paracoccidioides lutzii was recently included as a new causative species of paracoccidioidomycosis (PCM) and most cases have been reported from Brazil. According to available epidemiological information, P. lutzii is concentrated in the Middle-West region in Brazil, mainly in the state of Mato Grosso. However, clinical and laboratorial data available on patients infected with P. lutzii remain extremely limited. This work describes the clinical manifestations of 34 patients suffering from PCM caused by P. lutzii, treated along 5 years (2011-2017) at a reference service center for systemic mycoses in Mato Grosso, Brazil. Adult rural workers (men), aged between 28 and 67 predominated. All patients had the chronic form of the disease, and the oral mucosa (n = 19; 55.9%), lymph nodes (n = 23; 67.7%), skin (n = 16; 47.1%) and lung (n = 28; 82.4%) were the most affected sites. Alcohol intake (n = 19; 55.9%) and smoking (n = 29; 85.3%) were frequent habits among the patients. No patient suffered from any other life-threatening disease, such as tuberculosis, cancer or other inflammatory or infectious parasitic diseases. The positivity in culture examination (97.1%) was higher than that found for the direct mycological examination (88.2%). Particularly, one patient presented fungemia at diagnosis, which lead to his death. The time elapsed between the initial symptoms and the initiation of treatment of PCM caused by P. lutzii was 19.7 (31.5) months, with most patients diagnosed 7 months after the symptoms' onset. Compared with the classical clinical-epidemiological profile of PCM caused by P. brasiliensis, the results of this descriptive study did not show significant clinical or epidemiological differences that could be attributed to the species P. lutzii. Future studies may confirm or refute the existence of clinical differences between the two fungal species.
Hydroxamate Production as a High Affinity Iron Acquisition Mechanism in Paracoccidioides Spp
Iron is a micronutrient required by almost all living organisms, including fungi. Although this metal is abundant, its bioavailability is low either in aerobic environments or within mammalian hosts. As a consequence, pathogenic microorganisms evolved high affinity iron acquisition mechanisms which include the production and uptake of siderophores. Here we investigated the utilization of these molecules by species of the Paracoccidioides genus, the causative agents of a systemic mycosis. It was demonstrated that iron starvation induces the expression of Paracoccidioides ortholog genes for siderophore biosynthesis and transport. Reversed-phase HPLC analysis revealed that the fungus produces and secretes coprogen B, which generates dimerumic acid as a breakdown product. Ferricrocin and ferrichrome C were detected in Paracoccidioides as the intracellular produced siderophores. Moreover, the fungus is also able to grow in presence of siderophores as the only iron sources, demonstrating that beyond producing, Paracoccidioides is also able to utilize siderophores for growth, including the xenosiderophore ferrioxamine. Exposure to exogenous ferrioxamine and dimerumic acid increased fungus survival during co-cultivation with macrophages indicating that these molecules play a role during host-pathogen interaction. Furthermore, cross-feeding experiments revealed that Paracoccidioides siderophores promotes growth of Aspergillus nidulans strain unable to produce these iron chelators. Together, these data denote that synthesis and utilization of siderophores is a mechanism used by Paracoccidioides to surpass iron limitation. As iron paucity is found within the host, siderophore production may be related to fungus pathogenicity.
Molecular Tools for Detection and Identification of Paracoccidioides Species: Current Status and Future Perspectives
Paracoccidioidomycosis (PCM) is a mycotic disease caused by the Paracoccidioides species, a group of thermally dimorphic fungi that grow in mycelial form at 25 °C and as budding yeasts when cultured at 37 °C or when parasitizing the host tissues. PCM occurs in a large area of Latin America, and the most critical regions of endemicity are in Brazil, Colombia, and Venezuela. The clinical diagnosis of PCM needs to be confirmed through laboratory tests. Although classical laboratory techniques provide valuable information due to the presence of pathognomonic forms of Paracoccidioides spp., nucleic acid-based diagnostics gradually are replacing or complementing culture-based, biochemical, and immunological assays in routine microbiology laboratory practice. Recently, taxonomic changes driven by whole-genomic sequencing of Paracoccidioides have highlighted the need to recognize species boundaries, which could better ascertain Paracoccidioides taxonomy. In this scenario, classical laboratory techniques do not have significant discriminatory power over cryptic agents. On the other hand, several PCR-based methods can detect polymorphisms in Paracoccidioides DNA and thus support species identification. This review is focused on the recent achievements in molecular diagnostics of paracoccidioidomycosis, including the main advantages and pitfalls related to each technique. We discuss these breakthroughs in light of taxonomic changes in the Paracoccidioides genus.
Clinical and Eco-Epidemiological Aspects of a Novel Hyperendemic Area of Paracoccidioidomycosis in the Tocantins-Araguaia Basin (Northern Brazil), Caused by Paracoccidioides sp
Paracoccidioidomycosis (PCM) is the most prevalent systemic mycosis in Brazil. The disease is caused by dimorphic fungi nested within the Paracoccidioides genus. We described 106 PCM cases (47.1 cases/year) at the Tropical Diseases Public Hospital of Tocantins State. PCM was prevalent in males and rural workers over 50 years; the chronic pulmonary form predominated in 67% of cases. The male-to-female ratio was 2.65:1, with more women affected than other endemic regions of Brazil. Urban or indoor activities were reported in women and are ascribed to disease urbanization. qPCR-based assays confirmed the identification of Paracoccidioides DNA in 37 biological specimens. Paracoccidioides sp. DNA was found in 53% of the environmental samples, suggesting autochthonous infections. Therefore, the Tocantins-Araguaia basin must be considered a novel hyperendemic area of PCM in Brazil, reinforcing the importance of including PCM as a notifiable disease, requiring specific diagnosis and health measures.
Comparison of clinico-epidemiological and radiological features in paracoccidioidomycosis patients regarding serological classification using antigens from Paracoccidioides brasiliensis complex and Paracoccidioides lutzii
Genotyping of the genus Paracoccidioides showed its diversity and geographical distribution. Four species constituting the Paracoccidioides brasiliensis complex and Paracoccidioides lutzii are etiological agents of paracoccidioidomycosis (PCM). However, there are no studies comparing the clinical and epidemiological aspects between PCM caused by the P. brasiliensis complex and by P. lutzii. Demographic and clinical data from 81 patients with PCM-confirmed by mycological and/or histopathological examination-from Mato Grosso do Sul state (Brazil) were studied. All patients underwent serology by immunodiffusion with antigens obtained from the P. brasiliensis complex (ExoPb and gp43) and Cell Free Antigens obtained from P.lutzii (CFAPl).The cases were classified regarding their serological profile into three groups: G1: PCM patients seropositive to ExoPb and/or gp43 and seronegative to CFAPl (n = 51), assumed to have PCM caused by P. brasiliensis complex; G2: PCM patients seronegative to gp43 and seropositive to CFAPl (n = 16), with PCM caused by P. lutzii; and G3: PCM patients seropositive to ExoPb or gp43 and seropositive to CFAPl (n = 14), with undetermined serological profile, was excluded from the analyses. The Fisher's exact test or the Mann-Whitney U test, and cluster analysis according to Ward's method and Euclidean distance were used to analyze the results. Patients with serological profile suggestive of P. lutzii lived predominantly in municipalities in the Central and Southern regions of the state, while those with serological profile indicative of the P. brasiliensis complex were distributed throughout the state. No differences were found between the two groups regarding gender, age, schooling, rural work, clinical form, severity, organs involved, intensity of pulmonary involvement, degree of anemia, erythrocyte sedimentation rate values, and therapeutic response. PCM patients with serological profile suggestive of P. lutzii and PCM patients with serological profile indicative of P. brasiliensis complex showed the same clinical and radiological presentations.
Paracoccidioidomycosis cases by Paracoccidioides lutzii in southeastern Brazil
    Background and objective Paracoccidioidomycosis (PCM) is a systemic fungal disease caused by the thermodimorphic fungi P aracoccidioides spp . Their distribution is highly variable. Paracoccidioides lutzii is predominantly found in North and Middle-West Brazil and Ecuador. This study evaluated the clinicopathological characteristics of 10 patients diagnosed with PCM caused by P. lutzii in a reference center located in southeastern Brazil. Design Double immunodiffusion assay (DID) was used to investigate 35 patients’ sera with negative serology for P. brasiliensis against a P. lutzii CFA (cell-free antigen). Results Out of the 35 retested patients, 10 (28.6%) were positive for P. lutzii CFA. Four patients did not report any displacement to P. lutzii endemic areas. Our results reinforce the importance of using different antigens when testing patients with clinical manifestations of PCM and negative serological tests for P. brasiliensis , primarily in cases of the report of displacement to or former residence in P. lutzii endemic regions. Conclusions The availability of tests for different Paracoccidioides species antigens is fundamental for reaching an adequate diagnosis, patient follow-up, and definition of prognosis.