Establishment of a murine model for infection by Cladosporium cartionii / 中华皮肤科杂志

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 (immune-suppressed mice inoculated by C. Carrioni sus pension of 1 × 108 cfu conidia mL-1), group C (immune-suppressed mice inoculated by C. Carrioni suspen-sion of 1 × 106 cfu conidia mL-1), group D (healthy mice inoculated by sodium chloride solution). C. Car-rioni 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 ram, 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 nun 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.