Promising application of the SsCBF ELISA test to monitor the therapeutic response of feline sporotrichosis caused by Sporothrix brasiliensis from Brazilian epidemics

Abstract

Sporotrichosis zoonotic transmission by cats has obtained hyperendemic magnitude in Rio de Janeiro, Brazil. Atypical cases, relapses, and reinfections as well as reduced diagnostic sensitivity of conventional methods have been reported. Previously, the anti-SsCBF enzyme-linked immunosorbent assay (ELISA) test was shown to be useful as a diagnostic tool for human sporotrichosis. Effective diagnosis and treatment are critical to interrupt the chain of transmission of this major pathogen in Brazilian Public Health. To evaluate its applicability for feline sporotrichosis diagnosis and/or therapeutic follow-up, 15 domestic cats from Rio de Janeiro were clinically and laboratory monitored by cytopathology, culture, Sporothrix genotyping, and anti-SsCBF IgG levels. Subsequently, animals were divided into satisfactory and non-satisfactory therapeutic responders. Averages of antibody serum levels obtained for diagnosis (first consultation) compared with the levels found after follow-up (last consultation) were significantly different in both groups (p = 0.0002 and p = 0.038, respectively). We conclude that the SsCBF ELISA test can predict feline sporotrichosis therapeutic responses even for animals with distinct clinical evolutions.

Current Progress on Epidemiology, Diagnosis, and Treatment of Sporotrichosis and Their Future Trends

“…Therefore, serological methods can qualitatively and quantitatively evaluate the condition, generating fast results with high levels of specificity and sensitivity. It would already be a big step, as it would directly impact the diagnosis of the disease and the diagnostic screening and therapeutic monitoring of human and animal sporotrichosis, including those who develop atypical and severe forms [ 232 ].…”

Guideline for the management of feline sporotrichosis caused by Sporothrix brasiliensis and literature revision

“…The serology detection and quantification of IgG antibodies by the SsCBF-ELISA test was also studied as a therapeutic monitoring tool [105]. A serological scar may remain for months but the IgG levels drop accordingly to the therapeutic response.…”

Ocular lesions in a domestic feline:

“…The S. brasiliensis domestic feline reported here had an IgG titer compatible with a sporotrichosis positive diagnosis. Therefore, as previously described by our group (Baptista et al, 2021), this method could be applied for therapeutic follow-up, an important approach in severe cases.…”

“…Subsequently, this isolate was typed as S. brasiliensis by species-specific PCR targeting the calmodulin gene (CAL) as described by other studies (Macêdo-Sales et al, 2018bRodrigues et al, 2015). In parallel, IgG antibodies were detected by ELISA with the SsCBF antigen (Sporothrix schenckii ConA Binding Fraction) (Bernardes-Engemann et al, 2015) , with adaptations (Baptista et al, 2021), resulting in a positive diagnosis.…”