Fixed Cutaneous Sporotrichosis Due to Sporothrix globosa

On-site detection of Sporothrix globosa using immunoglobulin Y, magnetic separation and loop-mediated isothermal amplification

BACKGROUND

Sporothrix globosa (S. globosa) is an agricultural activity-related but neglected pathogenic fungus responsible for sporotrichosis. Timely detection is crucial for managing and preventing its spread. However, due to the lack of efficient recognition elements for enriching S. globosa, the current approaches for detecting S. globosa are not simple and/or sensitive enough. This hinders their wider application of fast screening.

RESULTS

Herein, we successfully prepared immunoglobulin Y (IgY) targeting S. globosa, and developed a rapid and accurate detection method, improving upon current limited and inadequate detection approaches. Our method combined the use of IgY and loop-mediated isothermal amplification (LAMP) to enhance detection sensitivity and specificity simultaneously. The IgY was fabricated on magnetic beads to specifically concentrate S. globosa in samples, while LAMP amplified the captured target after simple boiling DNA extraction. By using our method, as low as 4.66 × 102 Cells mL-1S. globosa was accurately detected in soil and corn straw samples. We further integrated this assay into a portable toolbox for sample-to-result detection in resource-limited areas. By using this toolbox, we have colorimetrically detected soil and corn straw samples contaminated by S. globosa, suggesting the promising on-site detection potential.

SIGNIFICANCE AND NOVELTY

A new IgY recognizing S. globosa was prepared. Through the combination of IgY enrichment and LAMP amplification, the detection sensitivity and specificity were improved simultaneously. This method eliminated thermal cycling, simplified the operation, and reduced the analysis time. Compared to existing methods, our approach is more suitable for on-site detection and can significantly improve public health responses to sporotrichosis outbreaks.

Difference analysis of cutaneous sporotrichosis between different regions in China: a secondary analysis based on published studies on sporotrichosis in China

Background

Cutaneous sporotrichosis is prevalent worldwide and a common subcutaneous fungal disease in northeast China. The incidence of cutaneous sporotrichosis in southern China cannot be ignored. Previous studies have revealed differences between different regions in China regarding populations susceptible to infection, cause of infection, and pathological mechanisms of sporotrichosis. Therefore, This study aimed to analyze the differences in the epidemiological characteristics of cutaneous sporotrichosis in different regions of China to provide a reference for regional prevention, control, and treatment.

Methods

We searched PubMed, EMBASE, Cochrane Library, CNKI, WanFang Data, and VIP for published reports on cutaneous sporotrichosis in China. The information about the characteristics of populations getting cutaneous sporotrichosis, causes of infection, disease types, and treatment regimens was extracted from studies to construct a knowledge database of cutaneous sporotrichosis in China. Taking the Qinling Mountains-Huaihe River line as the boundary to divide China into the northern and southern, the epidemiological characteristics of cutaneous sporotrichosis in two parts of China were analyzed.

Results

In northern China, more women than men get cutaneous sporotrichosis (60.4% vs. 39.6%), while it is the other way around in southern China (men vs. women: 50.6% vs. 49.4%). In northern China, the incidence of this disease was more concentrated in spring (34.0%) and winter (35.7%), while in southern China, this disease frequently spread in spring (48.1%) and summer (26.9%). In the north, cutaneous sporotrichosis usually affected the face (50.1%) and limbs (45.3%), while in the south, it targets limbs (72.6%). In northern China, potassium iodide (30.5%) and combination therapy (37.8%) were preferred, while in southern China, potassium iodide (86.0%) was the main choice. Although there was a significant difference in treatment regimens (P<0.05), no significant difference emerged in cure rates between northern and southern China (98.5% vs. 98.4%, P>0.05).

Conclusions

It is the first retrospective study on sporotrichosis in China. It describes the prevention of sporotrichosis in China since it was first reported and also reflects the differences in sporotrichosis between the northern and southern of China. This study provides a valuable reference for the prevention, control, and treatment of sporotrichosis in different regions of China.

Single nucleotide polymorphisms and chromosomal copy number variation may impact the Sporothrix brasiliensis antifungal susceptibility and sporotrichosis clinical outcomes

Feline-transmitted sporotrichosis has garnered attention due to the recent high incidence and the lack of efficient control in the epicenter of the epidemic, Rio de Janeiro, Brazil. Sporothrix brasiliensis is the major pathogen involved in feline-to-human sporotrichosis in Brazil and displays more virulent genotypes than the closely related species S. schenckii. Over the last two decades, several reports of antifungal-resistant strains have emerged. Sequencing and comparison analysis of the outbreak strains allowed us to observe that the azole non-wild-type S. brasiliensis strain CFP 1054 had significant chromosomal variations compared to wild-type strains. One of these variants includes a region of 231 Kb containing 75 duplicated genes, which were overrepresented for lipid and isoprenoid metabolism. We also identified an additional strain (CFP 1055) that was resistant to itraconazole and amphotericin B, which had a single nucleotide polymorphism in the tac1 gene. The patients infected with these two strains showed protracted clinical course and sequelae. Even though our sample size is modest, these results suggest the possibility of identifying specific point mutations and large chromosomal duplications potentially associated with antifungal resistance and clinical outcomes of sporotrichosis.

Biological and Clinical Attributes of Sporothrix globosa, a Causative Agent of Sporotrichosis

Sporotrichosis is an important subcutaneous mycosis with high prevalence and threat to human and animal health worldwide. Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are the main etiological agents of this disease; and even though many efforts have been made recently to understand the Sporothrix-host interaction, little is known about S. globosa, an underestimated species. This organism shows the lowest virulence among the members of the Sporothrix pathogenic clade and represents an important pathogenic agent due to its global distribution. Here, we offer a review with all the known information about S. globosa, including its genome and proteomic information, and compare it with S. schenckii and S. brasiliensis, to explain the differences observed among these species, in terms of virulence, the host immune response, and the antifungal sensitivity. Also, we provide the gene prediction of some S. globosa putative virulence factors.

Ocular Sporotrichosis

Sporotrichosis is a subacute or chronic mycosis predominant in tropical and subtropical regions. It is an infection of subcutaneous tissue caused by Sporothrix fungus species, but occasionally resulting in an extracutaneous condition, including osteoarticular, pulmonary, nervous central system, and ocular disease. Cases of ocular sporotrichosis are rare, but reports have been increasing in recent decades. Ocular infections usually occur in hyperendemic areas of sporotrichosis. For its classification, anatomic criteria are used. The clinical presentation is the infection in the ocular adnexal and intraocular infection. Ocular adnexa infections include palpebral, conjunctivitis, and infections of the lacrimal sac. Intraocular infection includes exogenous or endogenous endophthalmitis. Most infections in the ocular adnexal have been reported in Brazil, China and Peru, and intraocular infections are limited to the USA and Brazil. Diagnosis is performed from Sporothrix isolation in the mycological examination from ocular or skin samples. Both sporotrichosis in the ocular adnexa and intraocular infection can mimic several infectious and non-infectious medical conditions. Ocular adnexa infections are treated with potassium iodide and itraconazole. The intraocular infection is treated with amphotericin B. This review describes the clinical findings and epidemiological, diagnosis, and treatment of ocular sporotrichosis.