Sporotrichosis is a chronic (sub)cutaneous infection caused by thermodimorphic fungi in the order, Ophiostomatales. These fungi are characterized by major differences in routes of transmission, host ...predilections, species virulence, and susceptibilities to antifungals. Sporothrix species emerge in the form of outbreaks. Large zoonoses and sapronoses are ongoing in Brazil and China, respectively. Current diagnostic methods based on morphology and physiology are inaccurate due to closely related phenotypes with overlapping components between pathogenic and non-pathogenic Sporothrix. There is a critical need for new diagnostic tools that are specific, sensitive, and cost-effective.
We developed a panel of novel markers, based on calmodulin (CAL) gene sequences, for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. We identified specific PCR-based markers for S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida, and O. stenoceras. We employed a murine model of disseminated sporotrichosis to optimize a PCR assay for detecting Sporothrix in clinical specimens.
Primer-BLAST searches revealed candidate sequences that were conserved within a single species. Species-specific primers showed no significant homology with human, mouse, or microorganisms outside the Sporothrix genus. The detection limit was 10-100 fg of DNA in a single round of PCR for identifying S. brasiliensis, S. schenckii, S. globosa, S. mexicana, and S. pallida. A simple, direct PCR assay, with conidia as a source of DNA, was effective for rapid, low-cost genotyping. Samples from a murine model of disseminated sporotrichosis confirmed the feasibility of detecting S. brasiliensis and S. schenckii DNA in spleen, liver, lungs, heart, brain, kidney, tail, and feces of infected animals.
This PCR-based method could successfully detect and identify a single species in samples from cultures and from clinical specimens. The method proved to be simple, high throughput, sensitive, and accurate for diagnosing sporotrichosis.
...comparative genomics has enabled identification of a contraction of plant-degrading enzymes in S. brasiliensis and S. schenckii, which has been interpreted as adaptation from plants to animals 18. ...Here, we face a novel pathogen that emerged within a highly susceptible feline population and achieved efficient and massive transmission to humans 12-14. ...S. brasiliensis virulence is higher than that of other Sporothrix.
With increasing numbers of patients needing intensive care or who are immunosuppressed, infections caused by moulds other than Aspergillus spp or Mucorales are increasing. Although antifungal ...prophylaxis has shown effectiveness in preventing many invasive fungal infections, selective pressure has caused an increase of breakthrough infections caused by Fusarium, Lomentospora, and Scedosporium species, as well as by dematiaceous moulds, Rasamsonia, Schizophyllum, Scopulariopsis, Paecilomyces, Penicillium, Talaromyces and Purpureocillium species. Guidance on the complex multidisciplinary management of infections caused by these pathogens has the potential to improve prognosis. Management routes depend on the availability of diagnostic and therapeutic options. The present recommendations are part of the One World—One Guideline initiative to incorporate regional differences in the epidemiology and management of rare mould infections. Experts from 24 countries contributed their knowledge and analysed published evidence on the diagnosis and treatment of rare mould infections. This consensus document intends to provide practical guidance in clinical decision making by engaging physicians and scientists involved in various aspects of clinical management. Moreover, we identify areas of uncertainty and constraints in optimising this management.
After 1960, the increasing use of antibiotics became a major predisposing condition 4. Since 1970, prolonged neutropenia due to intensified cytotoxic treatment of hematologic malignancies was the ...leading risk factor in novel types of fusariosis 5. Since 1980, Fusarium infections have been seen in severely immunocompromised patients with a 100% mortality rate, e.g., in cases of cerebral involvement 6. To date, about 36 of the alleged human opportunists carry a name, while 38 are still unnamed and can only be identified by multilocus sequence analysis (MLSA). ...far, 21 species have been described with proven case reports 16, and more have been published in the literature.
Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. ...mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1α) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Paraná (PR, n = 4), São Paulo (SP, n =3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.
The genus Prototheca consists of achlorophyllic algae that are ubiquitous in the environment and also occur in animal intestines; occasionally, infections in humans and animals are observed. In this ...study, we conducted tests of assimilative abilities and thermotolerance in comparison with morphological characteristics of six opportunistic species (Prototheca blaschkeae, Prototheca bovis, Prototheca ciferrii, Prototheca cutis, Prototheca miyajii, and Prototheca wickerhamii) along with Prototheca paracutis. Five of the seven species could be differentiated by physiological characteristics, but P. wickerhamii and P. cutis had identical profiles. Of the cattle-associated species, only P. bovis was able to grow at 42°C. Both type strains of P. cutis and P. miyajii were most susceptible to ravuconazole compared with the other azoles.
The global burden of chromoblastomycosis Santos, Daniel Wagner C. L; de Azevedo, Conceição de Maria Pedrozo e Silva; Vicente, Vania Aparecida ...
PLoS neglected tropical diseases,
08/2021, Letnik:
15, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Background Chromoblastomycosis (CBM), represents one of the primary implantation mycoses caused by melanized fungi widely found in nature. It is characterized as a Neglected Tropical Disease (NTD) ...and mainly affects populations living in poverty with significant morbidity, including stigma and discrimination. Methods and findings In order to estimate the global burden of CBM, we retrospectively reviewed the published literature from 1914 to 2020. Over the 106-year period, a total of 7,740 patients with CBM were identified on all continents except Antarctica. Most of the cases were reported from South America (2,619 cases), followed by Africa (1,875 cases), Central America and Mexico (1,628 cases), Asia (1,390 cases), Oceania (168 cases), Europe (35 cases), and USA and Canada (25 cases). We described 4,022 (81.7%) male and 896 (18.3%) female patients, with the median age of 52.5 years. The average time between the onset of the first lesion and CBM diagnosis was 9.2 years (range between 1 month to 50 years). The main sites involved were the lower limbs (56.7%), followed by the upper limbs (19.9%), head and neck (2.9%), and trunk (2.4%). Itching and pain were reported by 21.5% and 11%, respectively. Malignant transformation was described in 22 cases. A total of 3,817 fungal isolates were cultured, being 3,089 (80.9%) Fonsecaea spp., 552 (14.5%) Cladophialophora spp., and 56 Phialophora spp. (1.5%). Conclusions and significance This review represents our current knowledge on the burden of CBM world-wide. The global incidence remains unclear and local epidemiological studies are required to improve these data, especially in Africa, Asia, and Latin America. The recognition of CBM as NTD emphasizes the need for public health efforts to promote support for all local governments interested in developing specific policies and actions for preventing, diagnosing and assisting patients.
Summary
Fungi in the order Mucorales cause acute, invasive and frequently fatal infections in susceptible patients. This study aimed to perform a systematic review of all reported mucormycosis cases ...during the last 25 years in Iran. After a comprehensive literature search, we identified 98 cases in Iran from 1990–2015. The mean patient age was 39.8 ± 19.2 years. Diabetes was the most common underlying condition (47.9%), and 22.4% of the patients underwent solid organ or bone marrow transplantation. The most common clinical forms of mucormycosis were rhinocerebral (48.9%), pulmonary (9.2%) and cutaneous (9.2%). Eight cases of disseminated disease were identified. Overall mortality in the identified cases was 40.8%, with the highest mortality rate in patients diagnosed with disseminated infection (75%). The mortality rate in rhinocerebral infection patients was significantly lower (45.8%). Rhinocerebral infection was the most common clinical manifestation in diabetes patients (72.9%). Patients were diagnosed using various methods including histopathology (85.7%), microscopy (12.3%) and culture (2.0%). Rhizopus species were the most prevalent (51.7%), followed by Mucor species (17.2%). Sixty‐nine patients were treated with a combination of surgery and antifungal therapy (resulting survival rate, 66.7%). Owing to the high mortality rate of advanced mucormycosis, early diagnosis and treatment may significantly improve survival rates. Therefore, increased monitoring and awareness of this life‐threatening disease is critical.
A severe outbreak of highly virulent and multi-resistant dermatophytosis by species in the
Trichophyton mentagrophytes
/
T
.
interdigitale
complex is ongoing in India. The correct identity of the ...etiologic agent is a much-debated issue. In order to define species limits, a taxonomic study was undertaken combining molecular, morphological, and physiological characteristics as evidence of classification. Molecular characteristics show that
T. mentagrophytes s. str
. and
T. interdigitale s. str
. can be distinguished with difficulty from each other, but are unambiguously different from the Indian genotype,
T
.
indotineae
by sequences of the HMG gene. The entities were confirmed by multilocus analysis using tanglegrams. Phenotypic characters of morphology and physiology are not diagnostic, but statistically significant differences are observed between the molecular siblings. These properties may be drivers of separate evolutionary trends.
Trichophyton mentagrophytes
represents the ancestral, homothallic cloud of genotypes with a probable geophilic lifestyle, while
T
.
indotineae
and
T
.
interdigitale
behave as anthropophilic, clonal offshoots. The origin of
T
.
indotineae
, which currently causes a significant public health problem, is zoonotic, and its emergence is likely due to widespread misuse of antifungals.
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