Abstract:

Objective To develop a murine model for infection by Cladosporium carrioni. Methods A total of 72 ICR mice were equally divided into 4 groups, group A （healthy mice inoculated by C. carrioni suspension of 1 × 108 cfu conidia mL-1）, group B （immuno-suppressed mice inoculated by C. carrioni suspension of 1 × 108 cfu conidia mL-1）, group C （immuno-suppressed mice inoculated by C. carrioni suspension of 1 × 106 cfu conidia mL-1）, group D （healthy mice inoculated by sodium chloride solution）. C. carrioni suspension or sodium chloride solution was subcutaneously inoculated into foot pads of mice. On day 7, 30 and 60 after inoculation, 6 mice were killed in each group followed by the measurement of thickness of foot pads, pathology and mycology of skin samples taken from foot pads. Results In group A, B and C, there were swelling, blackening, ulceration and crusts at the inoculation site of all mice, with a morbidity of 100%. The thickness of foot pads in group A on day 30 was significantly higher than that on day 7 （2.40 ± 0.45 mm vs 2.85 ± 0.47 mm, P < 0.05）, but lower than that on day 60 （1.64 ± 0.13 mm, P < 0.05）. In group B, increased thickness of foot pads was observed on day 30 compared with that on day 7 and day 60 （2.19 ± 0.27 mm vs 1.80 ± 0.21 mm and 1.86 ± 0.22 mm, respectively, both P < 0.05）, which was the case with group C （1.98 ± 0.06 mm vs 1.51 ± 0.11 mm and 1.82 ± 0.09 mm, respectively, both P < 0.05）. No significant changes occurred to the thickness of foot pads in group D from day 7 to day 60 （P > 0.05）. Pathological changes in group A, B and C included necrosis, abscess and chronic granuloma formation; dark brown sclerotic bodies were observed on HE and PAS staining as well as on direct microscopy; cultures of tissue samples grew Cladosporium carrionii. The mice in group D remained uninfected. Conclusion Mouse model for chromoblastomycosis may be established by subcutaneous inoculation of Cladosporium carrionii suspension into foot pads of healthy or immuno-suppressed mice.