Paracoccidioidomycosis due to Paracoccidioides brasiliensis S1 associated with acquired immunodeficiency syndrome: A case report

Humans vs. Fungi: An Overview of Fungal Pathogens against Humans

Human fungal diseases are infections caused by any fungus that invades human tissues, causing superficial, subcutaneous, or systemic diseases. Fungal infections that enter various human tissues and organs pose a significant threat to millions of individuals with weakened immune systems globally. Over recent decades, the reported cases of invasive fungal infections have increased substantially and research progress in this field has also been rapidly boosted. This review provides a comprehensive list of human fungal pathogens extracted from over 850 recent case reports, and a summary of the relevant disease conditions and their origins. Details of 281 human fungal pathogens belonging to 12 classes and 104 genera in the divisions ascomycota, basidiomycota, entomophthoromycota, and mucoromycota are listed. Among these, Aspergillus stands out as the genus with the greatest potential of infecting humans, comprising 16 species known to infect humans. Additionally, three other genera, Curvularia, Exophiala, and Trichophyton, are recognized as significant genera, each comprising 10 or more known human pathogenic species. A phylogenetic analysis based on partial sequences of the 28S nrRNA gene (LSU) of human fungal pathogens was performed to show their phylogenetic relationships and clarify their taxonomies. In addition, this review summarizes the recent advancements in fungal disease diagnosis and therapeutics.

Paracoccidioidomycosis cases by Paracoccidioides lutzii in southeastern Brazil

BACKGROUND AND OBJECTIVE

Paracoccidioidomycosis (PCM) is a systemic fungal disease caused by the thermodimorphic fungi Paracoccidioides 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.

Systematic review of neuroparacoccidioidomycosis: The contribution of neuroimaging

BACKGROUND

Advanced neuroimaging demonstrated that neurological involvement occurs in up to 30% of paracoccidioidomycosis (PCM) cases. Current knowledge of neuroparacoccidioidomycosis (NPCM) is based on a 2009 systematic review. However, in the last decade, several new cases have been published, with modern neuroimaging techniques.

OBJECTIVES

We believe a new systematic review is needed to summarise these advances.

METHODS

We searched PubMed/MEDLINE, Embase and LILACS for studies from January 2010 to May 2022. Case series and case reports of NPCM were included. We performed a metaproportion to estimate a summary proportion with 95% confidence intervals (CI).

RESULTS

Thirty-four studies including 104 patients were evaluated. We combined our data with the results from the previous review that included 257 cases, totalling 361 patients. We found no new important demographic, clinical or laboratory characteristics. On magnetic resonance imaging (MRI), we found that 72% (95%CI: 38-91) had hyperintensity on T1-weighted image; 84% (95%CI: 71%-92%) had hypointensity on T2-weighted image; 80% (95%CI: 66-89) had contrast enhancement with the classical ring-enhancing pattern. All 8 patients undergoing spectroscopy presented lipid peaks. We found a 16% mortality, lower than in the previous review (44%).

CONCLUSION

NPCM presents a characteristic pattern on MRI that may help to differentiate it from other causes of single or multiple brain lesions. Albeit there is a frequent pattern, it is not specific, as other granulomatous diseases may show similar findings. Advances in neuroimaging with early diagnosis and appropriate management of the disease may have contributed to reducing its mortality.

A New Duplex PCR-Assay for the Detection and Identification of Paracoccidioides Species

Paracoccidioidomycosis (PCM) is a life-threatening systemic fungal infection caused by members of the Paracoccidioides brasiliensis complex and P. lutzii. Routine diagnoses of PCM down to the species level using classical mycological approaches are unspecific due to overlapping phenotypes. There is an urgent need for specific, sensitive, and cost-effective molecular tools to diagnose PCM. Variation among the exon-2 of the gp43 gene was exploited to design species-specific primer pairs to discriminate between members of the P. brasiliensis complex and P. lutzii in a duplex PCR assay. Primer-BLAST searches revealed highly species-specific primers, and no significant region of homology was found against DNA databases except for Paracoccidioides species. Primers PbraCx-F and PbraCx-R targeting P. brasiliensis DNA produced an amplicon of 308 bp, while primers Plu-F and Plu-R targeting P. lutzii DNA generated an amplicon of 142 bp. The lower limit of detection for our duplex PCR assay was 1 pg of gDNA. A panel of 62 Paracoccidioides revealed 100% specificity (AUC = 1.000, 95%CI 0.972-1.000, p < 0.0001) without cross-reacting with other medically relevant fungi or human DNA. As a proof of concept, we demonstrated the accurate identification of the P. brasiliensis complex (n = 7) or P. lutzii (n = 6) from a broad range of formalin-fixed, paraffin-embedded (FFPE) tissues of PCM patient's organs. In four cases, FFPE PCR results confirmed, for the first time, co-infection due to P. brasiliensis (S1) and P. lutzii in the same biopsy. Our duplex PCR assay is useful to detect and differentiate members of the P. brasiliensis complex and P. lutzii, providing clinical laboratories with an important tool to be applied routinely, especially in atypical cases such as those featuring negative serology and positive mycological examination of clinical specimens as well as for the investigation of putative co-infection cases. This will likely benefit thousands of infected patients every year in a wide area of the Americas.