Trichophyton rubrum infection of guinea pig model construction
|School||Peking Union Medical College , China|
|Course||Dermatology and Venereology|
|Keywords||Trichophyton rubrum Direct microscopy Ruby Guinea pig Hair Glucocorticoids Animal Model Experimental Animals Perforation test Colony growth|
1 Lubiqieke Trichophyton, also known as Trichophyton rubrum Lubiqieke variant, first described in 1981 by the Kane is a new kind of dermatophytes, the latter has proved to be one of the variants of Trichophyton rubrum . We jock itch from a male patient's skin lesions were isolated and identified a Lubiqieke Trichophyton. Methods dander direct microscopic examination confirmed fungal infections, cultured for colony and microscopic morphology, biochemical experiments, amplification of fungal rDNA ITS region and sequencing were used to identify isolates. Results strains in physiological and morphological characteristics of the following aspects in line Lubiqieke Trichophyton characteristics: (1) SDA for the fluffy colonies, PDA to produce the red pigment, violet pigment granules central colony formation; ( 2) small pear-shaped or rod-like conidia, pencil-shaped large conidia cultured under normal conditions can produce rich arthrospore; (3) urease test positive hair perforation test was negative; (4) of ITS1 rDNA amplified strains -4 area, sequenced with known Trichophyton rubrum and Trichophyton Lubiqieke blast sequence alignment, show exactly the same. Conclusion This is the first time China pathogenic strains were isolated and identified dermatophytes - Lubiqieke Trichophyton. 2 by glucocorticoids intervention to change the immune status of guinea pigs, it can not effectively remove vaccination Trichophyton rubrum, Trichophyton rubrum infection in order to establish an animal model of guinea pigs. Methods of clinical specimens from selected three different strains of Trichophyton rubrum, colonies were short fluffy, powdery colonies and Lubiqieke Trichophyton rubrum (short villous colonies, urease test positive). 3 days before inoculation, 1 day to give Triamcinolone acetonide injection 20mg/kg · d thigh intramuscular pretreatment, after inoculation 7.5mg/kg dexamethasone injection intraperitoneal injection repeated after 1 injection every day , a total of four times the additional application of the method to promote Trichophyton rubrum infection animal model; using direct microscopy, fungal culture and histopathological results of method validation infection. Result in the application of the appropriate dose and route of glucocorticoid intervention, Trichophyton rubrum six days after inoculation, animals began to appear positive direct microscopy, to 8 days, 16 Trichophyton rubrum infection in experimental animals are direct microscopy is positive. 10 days after infection, direct microscopy remains positive, ingrown hairs see also hyphae or spores, fungal cultures were inoculated with bacteria with the same visible colonies. Histopathology showed: the hair follicle infundibulum see hyphae and spores, hair roots see hyphae and spores. Conclusion glucocorticoid intervention guinea pigs infected with Trichophyton rubrum can establish an animal model. 3 of Trichophyton rubrum on different animal hair degradation. Methods: In vitro liquid cultures of Trichophyton rubrum and Trichophyton Lubiqieke, adding a few root hairs mice or guinea pigs to low concentrations of yeast extract provide nutrients necessary for survival strain, strain carbon source for growth and nitrogen from the decomposition of animal hair strains obtained colonies were observed after 2 weeks of culture growth conditions and animal hair structure changes, Trichophyton mentagrophytes as a positive control. Results: After 2 weeks, Trichophyton rubrum, Trichophyton Lubiqieke and Trichophyton mentagrophytes in guinea pigs and mice can grow hair, colony growth, the light microscope, animal hair normal structural damage, transverse blurred lines disappear. Conclusion: Trichophyton rubrum and Trichophyton mentagrophytes in vitro can be decomposed as guinea pigs or mice hair as a nutrient to maintain colony growth.