Diagnosis and Manifestation of Encephalitozoonosis in Mice after Experimental Infection with Different Species and Application of Dexamethasone

Abstract

Twenty-eight BALB/c mice were infected with different strains of Encephalitozoon species (Encephalitozoon cuniculi II - mouse type, E. cuniculi III - dog type, Encephalitozoon hellem, Encephalitozoon intestinalis). Five of them were infected with E. cuniculi II (mouse type) and simultaneously immunosuppressed with dexamethasone. Clinical signs of encephalitozoonosis were not remarkable. Ascites was found in two mice of dexamethasone-treated group 14 days post-infection (p.i.). The histopathological changes were found mainly in spleen and liver in the form of lymphoepithelioid granuloma. Spores were found in faeces since day 14 p.i. and visualized by Calcoflour White M2R. After cultivation on cellular cultures (VERO E6 - monkey kidney cells, RK-13 - rabbit kidney fibroblasts), the species differentiation was performed by PCR using panmicrosporidial primers (PMP1, PMP2) and specific primers (ECUN-F, ECUN-R, V1, SI-500). The differences were recorded in the immune response of immunocompetent and immunosuppressed mice. At day 60 p.i., the titres of specific antibodies measured by indirect immunofluorescence antibody test were lower (1:4096) in dexamethasone-treated mice when compared with non-immunosuppressed animals (1:8196). The significant increases of antibody titres were recorded in particular infected groups within the experiment (P < 0.01 between day 14 p.i. and day 30 p.i., P < 0.001 between day 14 p.i. and day 60 p.i.). Experimental encephalitozoonosis in non-immunosuppressed and immunosuppressed mice provides a useful model for the study of immune response and lesions associated with these protozoans.

Microsporidiosis in Vertebrate Companion Exotic Animals

“…Seroconversion precedes renal shedding and is still detectable afterwards [ 77 ] ( Figure 1 ). Whether or not shedding increases in immunocompromised rabbits is debatable: some authors have not shown any effect of dexamethasone administration on spore excretions [ 39 ] while others suggest the contrary [ 100 ], as dexamethasone has been reported to increase spore excretion in mice [ 101 , 102 ]. Urinary spore excretion typically occurs between four weeks and 12 weeks post-infection [ 77 ], which may be earlier than the development of clinical signs.…”

Pseudoloma neurophilia infections in zebrafish Danio rerio: effects of stress on survival, growth, and reproduction

“…We recently described increases in zebrafish whole-body cortisol following chronic crowding or acute handling stress (Ramsay et al 2006; Ramsay et al accepted). In other animal models exposure to corticosteroids generally increases the intensity of microsporidiosis (Feng et al 2006; Herich et al 2006; Lovy et al 2008). …”

Microsporidia Ser/Thr Protein Phosphatase PP1 Targets DCs MAPK Pathway and Impairs Immune Functions

“…In vivo infection of microsporidia to wild-type mice was achieved as follows. 1X10 7 E. hellem spores/mice/day were inoculated into wild-type mice for two days, the mice were transiently pre-treated with dexamethasone (Aladin, Cas 2392-39-4, China) to increase infection rates but no significant effects on immune cells as assessed in our established murine model and other reports (35)(36)(37)(38). The control groups were either treated with PBS, LPS (5mg/kg), or S. aureus (1X10 7 CFU/mice).…”