Susceptibility of congenitally athymic (nude) mice to sporotrichosis

Abstract

Congenitally athymic (nu/nu) mice were found to be more susceptible to intravenous challenge with Sporothrix schenckii than their phenotypically normal (nu/+) littermates as measured by lethality and the number of viable yeast cells in the liver 7 days postinfection. Thymus reconstitution of nu/nu mice (nu/thy) conferred a significant degree of resistance to sporotrichosis. Immunization greatly enhanced the resistance of nu/thy and nu/+ mice, but unexpectedly increased the susceptibility of nu/nu mice. The susceptibility of nonimmunized nu/nu mice and the finding that thymus transplants augmented resistance to sporotrichosis suggest that T lymphocytes are critical to host defense.

Detrimental role of endogenous nitric oxide in host defence against Sporothrix schenckii

“…Lymphocyte proliferation was determined by [ 3 H]-thymidine ( 3 HTdR) incorporation during the last 12 hr. Spleen cells incubated with medium alone presented background 3 HTdr uptakes of 600 ± 205 and 800 ± 105. P < 0Á05 (a, log rank test; b and c, ANOVA followed by Bonferroni's t-test), when compared to non-infected mice (*).…”

Use of a mouse model to evaluate clinical and environmental isolates of Sporothrix spp. from the largest U.S. epidemic of sporotrichosis

“…Numerous investigators have reported animal models with fatal infections following intravenous injection of conidial or yeast suspensions of S. schenckii (1,4,10,17). In general, inoculation of .106 cells per mouse resulted in uniform mortality.…”

Relationships among genotypes, virulence and clinical forms of Sporothrix schenckii infection

“…LS and FCS account for the majority of clinical cases, and disseminated sporotrichosis (DS) is infrequent [1–3]. It is well‐known that the clinical form of sporotrichosis depends on the host's immune condition [4–6]. DS is reported mostly among immunocompromised hosts, especially AIDS patients [7–11].…”