Uncommon Clinical Presentations of Sporotrichosis: A Two-Case Report

Round 1

Reviewer 1 Report

Did the Sabs agar contain chloramphenicol?

The last sentence under case 2 is unclear.

Nicely written paper.

The intro and discussion could be shortened, but this is not critical

Author Response

Response to Reviewer 1 Comments

First of all, I would like to thank the reviewer 1 for the work they have done in correcting our manuscript, which has been very helpful. We have answered the questions and addressed the corrections suggested to us:

Point 1: Did the Sabs agar contain chloramphenicol?

Response 1: Yes, we used it.

Point 2: The last sentence under case 2 is unclear.

Response 2: We changed the last sentence:

Case 2

A 21-year-old male patient residing in Guanajuato, Mexico, visited a medical consultation due to the presence of multiple nodular and warty plaques (some ulcerated and with scabs) that affected the anterior and posterior areas of the chest, abdominal wall, arms, and forearms (Figure 2A and 2B). The patient reported a two-year evolution without healing after multiple empirical treatments. Tuberculosis verrucous cutis, chromoblastomycosis, and sporotrichosis were suspected. A skin test was performed with sporotrichin, followed by biopsy and culturing in Sabouraud medium at 28C, during 8 days. The skin test was positive, showing an induration >5 mm in diameter. The main histopathological finding was suppurative granuloma; no fungal elements were found (Figure 2C). The growth of a colony morphologically compatible with Sporothrix spp. was observed in the culture. The identification of the S. schenckii sensu stricto species was carried out by amplification of a 331 bp fragment of the CAL gene11, as described in case 1. The patient received 3 g of KI daily for 12 months and showed significant improvement. However, there were still some injuries and active infection was observed (Figure 2D); thus, treatment was continued for six more months.

Point 3: Nicely written paper.

Response 3; Thank you

Point 4: The intro and discussion could be shortened, but this is not critical

Response 4: It is quite difficult for us to summarize the text further. We think it would dilute your understanding

Author Response File: Author Response.docx

Reviewer 2 Report

This paper outlines case studies for two uncommon presentations of sporotrichosis and describes their diagnosis and treatment. It is concise, well written and very clear.  I have just a few fairly minor comments and also attach a marked-up pdf with some editorial suggestions.

1. It would be helpful to supply a bit more information in the introduction about the diagnostic procedures for sporotrichosis, in particular the PCR test. Presumably this test enables discrimination of the different species? It would also be helpful to know which of the species are likely to be present in Mexico.
2. Similarly, it would be good to have information in the introduction on current treatment regimes. This was the first time I had heard about using oral potassium iodide in the treatment of an invasive fungal disease, and it would be helpful for the non-specialist to be given a bit more background on this.
3. The authors attribute dissemination to non-specific antibiotic treatment. Is this a correct assumption? Or do you mean that the delay caused by incorrect diagnosis and treatment led to eventual dissemination?

Author Response

Response to Reviewer 2 Comments

First of all, I would like to thank the reviewer 2 for the work they have done in correcting our manuscript, which has been very helpful. We have answered the questions and addressed the corrections suggested to us:

 This paper outlines case studies for two uncommon presentations of sporotrichosis and describes their diagnosis and treatment. It is concise, well written and very clear.  I have just a few fairly minor comments and also attach a marked-up pdf with some editorial suggestions.

Point 1: It would be helpful to supply a bit more information in the introduction about the diagnostic procedures for sporotrichosis, in particular the PCR test. 

Response 1: The gold standard for the diagnosis of sporotrichosis are based on morphological and physiological characteristics, however these are imprecise due to closely related phenotypes with overlapping components between different Sporothrix species. Therefore, molecular techniques allow more precise species identification and differentiation of these closely-related fungi. Molecular identification techniques include the amplification and sequencing of genetic markers such as the ribosomal internal transcribed space, b-tub (beta-tubulin), CAL (calmodulin), and EF (translation elongation factor) which are recognized as fungal "barcoding" genes. For Sporothrix species differentiation, end point PCR and multiplex real time PCR using a calmodulin gene, it’s one of the most used genetic markers. (See reference 11).

Point 2: Presumably this test enables discrimination of the different species?

Response2: The calmodulin gene is one of the most used markers for the identification of Sporothrix schenckii complex species. We used a series of primers (6 sets) of the calmodulin gene that allow the differentiation of S. brasiliensis, S. schenckii, S. globosa, S. mexicana, S. pallida and Ophiostoma stenocerans. The primers were designed from the sequences of the calmodulin gene, using the polymorphism areas of this gene in each species, the species-specific primers were selected.

This panel of novel markers, based on calmodulin (CAL) gene sequences, can be used for the large-scale diagnosis and epidemiology of clinically relevant members of the Sporothrix genus, and its relative, Ophiostoma. These species-specific primers can be applied in epidemiology, clinical diagnosis, and experimental studies of sporotrichosis. Improvements in early diagnosis and surveillance systems may facilitate rapid identification and control of future outbreaks.

Rodrigues, A.M.; de Hoog, G.S.; de Camargo, Z.P. Molecular diagnosis of pathogenic Sporothrix species. PLoS Negl Trop Dis. 2015;9: e0004190.

Point 3: It would also be helpful to know which of the species are likely to be present in Mexico.

Response 3: Acording to this article that has just come out and that handles a systematic review, the most frequent species is S. schenckii and the second is S. globosa.

Toriello, C.; Brunner-Mendoza, C.; Ruiz-Baca, E.; Duarte-Escalante E.; Pérez-Mejía, A.; Reyes-Montes, M.R. Sporotrichosis in Mexico. Braz J Microbiol. 2021;52::49-62. doi: 10.1007/s42770-020-00387-x. 

Point 4: Similarly, it would be good to have information in the introduction on current treatment regimes. 

Response 4: Cutaneous disseminated sporotrichosis is a fungal infection only affecting the skin and, in our experience, we have used potassium iodide, because it is cheaper, well tolerated, easy to administer and, due to the patients’ financial circumstances, we give it for free.

Point 5: This was the first time I had heard about using oral potassium iodide in the treatment of an invasive fungal disease, and it would be helpful for the non-specialist to be given a bit more background on this.

Response 5: For disseminated cutaneous Sporotrichosis, when there are indications of being invasive, the drug of choice should be amphotericin B, preferably the liposomal version, between 3 and 5 mg / kg / day, but if there is only amphotericin B deoxycholate, it is recommended to use it in doses ranging from 0.7 to 1 mg / kg / day. When it comes to a disseminated cutaneous variant without indications of being invasive, it is recommended to use the conventional scheme for a fixed or lymphangitic subcutaneous, potassium iodide (KI) administered in diluted form or in drops in doses of 200 mg / day for 3-6 months approximately.

Bonifaz, A.; Tirado-Sánchez A. Cutaneous Disseminated and Extracutaneous Sporotrichosis: Current Status of a Complex Disease. J Fungi. (Basel) 2017;3:6. doi: 10.3390/jof3010006.

Kauffman, C.A.; Bustamante, B.; Chapman, S.W.; Pappas, P.G.; Infectious Diseases Society of America. Clinical practice guidelines for the management of sporotrichosis: 2007 update by the Infectious Diseases Society of America. Clin Infect Dis. 2007;45:1255-65. doi: 10.1086/522765.

Point 6: The authors attribute dissemination to non-specific antibiotic treatment. Is this a correct assumption? Or do you mean that the delay caused by incorrect diagnosis and treatment led to eventual dissemination?

Response 6: It is a spectral clinical form related to immunological background and not with previous antibacterial drugs.

Author Response File: Author Response.docx

Reviewer 3 Report

This case report of two Sporothrix cutaneous infections is clearly written and appears to be accurately reported and documented.

The last sentence in Section 3 as a word missing: perhaps “and”?

Author Response

Response to Reviewer 3 Comments

First of all, I would like to thank the reviewer 3 for the work they have done in correcting our manuscript, which has been very helpful. We have answered the questions and addressed the corrections suggested to us:

Point 1: This case report of two Sporothrix cutaneous infections is clearly written and appears to be accurately reported and documented.

The last sentence in Section 3 as a word missing: perhaps “and”?

Response 1: Yes, it is a mistake, we have removed the word  "and"

Author Response File: Author Response.docx