Emergence of zoonotic sporotrichosis in Brazil: a genomic epidemiology study.

BACKGROUND: Zoonotic sporotrichosis is a neglected fungal disease, whereby outbreaks are primarily driven by Sporothrix brasiliensis and linked to cat-to-human transmission. To understand the emergence and spread of sporotrichosis in Brazil, the epicentre of the current epidemic in South America, we aimed to conduct whole-genome sequencing (WGS) to describe the genomic epidemiology. METHODS: In this genomic epidemiology study, we included Sporothrix spp isolates from sporotrichosis cases from Brazil, Colombia, and the USA. We conducted WGS using Illumina NovaSeq on isolates collected by three laboratories in Brazil from humans and cats with sporotrichosis between 2013 and 2022. All isolates that were confirmed to be Sporothrix genus by internal transcribed spacer or beta-tubulin PCR sequencing were included in this study. We downloaded eight Sporothrix genome sequences from the National Center for Biotechnology Information (six from Brazil, two from Colombia). Three Sporothrix spp genome sequences from the USA were generated by the US Centers for Disease Control and Prevention as part of this study. We did phylogenetic analyses and correlated geographical and temporal case distribution with genotypic features of Sporothrix spp isolates. FINDINGS: 72 Sporothrix spp isolates from 55 human and 17 animal sporotrichosis cases were included: 67 (93%) were from Brazil, two (3%) from Colombia, and three (4%) from the USA. Cases spanned from 1999 to 2022. Most (61 [85%]) isolates were S brasiliensis, and all were reported from Brazil. Ten (14%) were Sporothrix schenckii and were reported from Brazil, USA, and Colombia. For S schenckii isolates, two distinct clades were observed wherein isolates clustered by geography. For S brasiliensis isolates, five clades separated by more than 100 000 single-nucleotide polymorphisms were observed. Among the five S brasiliensis clades, clades A and C contained isolates from both human and cat cases, and clade A contained isolates from six different states in Brazil. Compared with S brasiliensis isolates, larger genetic diversity was observed among S schenckii isolates from animal and human cases within a clade. INTERPRETATION: Our results suggest that the ongoing epidemic driven by S brasiliensis in Brazil represents several, independent emergence events followed by animal-to-animal and animal-to human transmission within and between Brazilian states. These results describe how S brasiliensis can emerge and spread within a country. FUNDING: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil; the São Paulo Research Foundation; Productivity in Research fellowships by the National Council for Scientific and Technological Development, and Ministry of Science and Technology of Brazil.

Bimodal distribution of azole susceptibility in Sporothrix brasiliensis isolates in Brazil.

Sporothrix brasiliensis is an emerging zoonotic fungal pathogen that can be difficult to treat. Antifungal susceptibility testing was performed on the mold phase of a convenience sample of 61 Sporothrix spp. isolates from human and cat sporotrichosis cases in Brazil using the Clinical and Laboratory Standards Institute standard M38. A bimodal distribution of azole susceptibility was observed with 50% (28/56) of S. brasiliensis isolates showing elevated itraconazole minimum inhibitory concentrations ≥16 µg/mL. Phylogenetic analysis found the in vitro resistant isolates were not clonal and were distributed across three different S. brasiliensis clades. Single nucleotide polymorphism (SNP) analysis was performed to identify potential mechanisms of in vitro resistance. Two of the 28 resistant isolates (MIC ≥16 mg/L) had a polymorphism in the cytochrome P450 gene, cyp51, corresponding to the well-known G448S substitution inducing azole resistance in Aspergillus fumigatus. SNPs corresponding to other known mechanisms of azole resistance were not identified in the remaining 26 in vitro resistant isolates.

Whole-genome sequencing of Candida haemulonii species complex from Brazil and the United States: Genetic diversity and antifungal susceptibility.

Candida haemulonii complex species can be multidrug-resistant and cause infections such as candidemia. This study determined the genetic relationship between isolates from Brazil and the United States through whole-genome sequencing and performed antifungal susceptibility testing to investigate drug resistance. Contrary to what is widely described, most isolates were susceptible to azoles. However, an atypical susceptibility profile was found in 50% of Candida pseudohaemulonii strains, including resistance to the three echinocandins. Isolates from both countries formed distinct clusters with wide genetic diversity. Isolates from three hospitals in Brazil were clonal and involved in candidemia cases, pointing to the importance of improving hospital infection control measures and molecular identification.

Candida haemulonii complex species is worldwide distributed, and this study aimed to evaluate the resistance to antifungal drugs in cases from Brazil and the United States, and also compare their genetic relationships. A total of 50 strains were studied; most of them from Brazil were from cases of bloodstream infections, while the strains from the United States came from cases of wounds and may be associated with diabetic patients. The vast majority of strains were resistant to amphotericin B, one of the most effective drugs, and susceptible to fluconazole. In addition, 50% of C. pseudohaemulonii strains were resistant to echinocandins. The strains from Brazil and the United States had no genetic relationship and formed two distinct groups. In three Brazilian hospitals, strains were clonal, indicating an intra-hospital transmission. Our findings contribute to guiding therapy in bloodstream fungal infections caused by C. haemulonii species and alerting for nosocomial transmission of this yeast complex species.

Molecular epidemiology and clinical-laboratory aspects of chromoblastomycosis in Mato Grosso, Brazil.

INTRODUCTION: Chromoblastomycosis is a disease caused by melanized fungi, primarily belonging to the genera Fonsecaea and Cladophialophora, mainly affecting individuals who are occupationally exposed to soil and plant products. This research aimed to determine the clinical, epidemiological and laboratory characteristics of chromoblastomycosis in the state of Mato Grosso, Brazil. MATERIALS AND METHODS: Patients diagnosed with chromoblastomycosis treated at the Júlio Müller University Hospital, Cuiabá, Brazil, from January 2015 to December 2020, whose isolates were preserved in the Research Laboratory of the Faculty of Medicine of the Federal University of Mato Grosso. Isolates were identified by partly sequencing the Internal Transcribed Spacer (ITS) and ß-tubulin (BT2) loci. AFLP fingerprinting was used to explore the genetic diversity. Susceptibility to itraconazole, voriconazole, 5-fluorocytosine, terbinafine and amphotericin B was determined by the broth microdilution technique. RESULTS: Ten patients were included, nine were male (mean age = 64.1 years). Mean disease duration was 8.6 years. Lesions were mainly observed in the lower limbs. Predominant clinical forms were verrucous and scarring. Systemic arterial hypertension and type II diabetes mellitus were the predominant comorbidities. Leprosy was the main concomitant infectious disease. Fonsecaea pedrosoi was the unique aetiological agent identified with moderate genetic diversity (H = 0.3934-0.4527; PIC = 0.3160-0.3502). Antifungal agents with the highest activity were terbinafine, voriconazole and itraconazole. CONCLUSION: Chromoblastomycosis is affecting the poor population in rural and urban areas, mainly related to agricultural activities, with F. pedrosoi being the dominant aetiologic agent. All isolates had low MICs for itraconazole, voriconazole and terbinafine, confirming their importance as therapeutic alternatives for chromoblastomycosis.

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.

Factors influencing susceptibility testing of antifungal drugs: a critical review of document M27-A4 from the Clinical and Laboratory Standards Institute (CLSI).

Due to the increasing numbers of fungal infections and the emergence of drug-resistant fungi, optimization and standardization of diagnostic methods for the measurement of antifungal susceptibility are ongoing. The M27-A4 document by the US Clinical and Laboratory Standards Institute (CLSI) is presently used for the interpretation of minimum inhibitory concentrations of major opportunistic yeast species as measured by broth microdilution testing in many countries. Although microdilution is considered a benchmark for reproducible and accurate results, increased testing capacity, and limited human bias, the method is often inaccessible to routine clinical laboratories and researchers, especially in low-income countries. Furthermore, several studies suggest that there are still a considerable number of factors that make the estimation of in vitro activity of antifungal agents challenging. This review article summarizes the limitations of the M27-A4 standard which, despite the advances and improvements obtained by the standardization of antimicrobial resistance testing methods by CLSI, still persist.

Eighty Years of Mycopathologia: A Retrospective Analysis of Progress Made in Understanding Human and Animal Fungal Pathogens.

Mycopathologia was founded in 1938 to 'diffuse the understanding of fungal diseases in man and animals among mycologists.' This was an important mission considering that pathogenic fungi for humans and animals represent a tiny minority of the estimated 1.5-5 million fungal inhabitants on Earth. These pathogens have diverged from the usual saprotrophic lifestyles of most fungi to colonize and infect humans and animals. Medical and veterinary mycology is the subdiscipline of microbiology that dwells into the mysteries of parasitic, fungal lifestyles. Among the oldest continuing scientific publications on the subject, Mycopathologia had its share of 'classic papers' since the first issue was published in 1938. An analysis of the eight decades of notable contributions reveals many facets of host-pathogen interactions among 183 volumes comprising about 6885 articles. We have analyzed the impact and relevance of this body of work using a combination of citation tools (Google Scholar and Scopus) since no single citation metric gives an inclusive perspective. Among the highly cited Mycopathologia publications, those on experimental mycology accounted for the major part of the articles (36%), followed by diagnostic mycology (16%), ecology and epidemiology (15%), clinical mycology (14%), taxonomy and classification (10%), and veterinary mycology (9%). The first classic publication, collecting nearly 200 citations, appeared in 1957, while two articles published in 2010 received nearly 150 citations each, which is notable for a journal covering a highly specialized field of study. An empirical analysis of the publication trends suggests continuing interests in novel diagnostics, fungal pathogenesis, review of clinical diseases especially with relevance to the laboratory scientists, taxonomy and classification of fungal pathogens, fungal infections and carriage in pets and wildlife, and changing ecology and epidemiology of fungal diseases around the globe. We anticipate that emerging and re-emerging fungal pathogens will continue to cause significant health burden in the coming decades. It remains vital that scientists and physicians continue to collaborate by learning each other's language for the study of fungal diseases, and Mycopathologia will strive to be their partner in this increasingly important endeavor to its 100th anniversary in 2038 and beyond.

Disseminated amphotericin-resistant fusariosis in acute leukemia patients: report of two cases.

Disseminated fusariosis has emerged as a significant, usually fatal infection in immunocompromised hosts despite antifungal treatment. We describe here two patients with acute leukemia who developed disseminated amphotericin-resistant fusariosis, and review of six studies of cases series in the literature. Two Fusarium solani strains were isolated from blood and skin cultures of one patient, and one strain from the blood culture of the second patient. Both patients died despite antifungal treatment. Strains were identified by sequencing of ITS1 and ITS4 regions. Random amplified polymorphic DNA analysis of the three F. solani isolates showed a low degree of similarity. Screening for Fusarium spp. contaminants within our facility was negative. Using the CLSI M-38-A2 broth dilution method and E tests(®), we found that the MICs were low for voriconazole (0.12 and 0.5 mg/L, respectively), unexpectedly high for amphotericin B (≥8 and ≥32 µg/mL, respectively) and itraconazole (≥16 mg/ml). Patients with leukemia or persistent neutropenia should be assessed for disseminated fungal infections, including biopsy and skin cultures. Antifungal susceptibility tests are important due to the possibility of the strains being amphotericin resistant. Treatments must be aggressive, with high doses of antifungals or combined therapy.

Vulvovaginal candidiasis in Mato Grosso, Brazil: pregnancy status, causative species and drugs tests.

Causative agent in majority of VVC is Candida albicans, but infection due to non-C. albicans is common. Use of empiric antifungal therapy in Brazil due to syndromic management of vulvovaginitis could act as risk factor for increase resistance among VVC causative agents. From Mato Grosso patients, 160 with culture-proved among 404 women who had clinical symptoms of VVC, were enrolled in this study. 70 non-pregnant women and 90 pregnant women were included. Candida albicans was the most prevalent, representing 72.9% in the non-pregnant group and 92.3% in the pregnant group. Differences in species distribution were noted between the two groups, being C. parapsilosis the second more prevalent species among non-pregnant women. Susceptibility testing revealed high susceptibility to fluconazole (except for C. krusei), itraconazole, ketoconazole, and amphotericin B regardless the species (C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, C. krusei) analyzed.

Antifungal drug susceptibility profile of Pichia anomala isolates from patients presenting with nosocomial fungemia.

In vitro susceptibility of 58 isolates of Pichia anomala to five antifungal drugs using two broth microdilution methods (CLSI and EUCAST) was analyzed. Low susceptibility to itraconazole was observed. Fluconazole, voriconazole, amphotericin B, and caspofungin showed good antifungal activity, although relatively high drug concentrations were necessary to inhibit the isolates.