Study On Microbiol Characteristics Of Cladosporium Cladosporioides

Relatively little information is available on the microbiol characteristics of cladosporium cladosporioides. Because of the increasing number of immunocompromised patients, the number of fungi causing subcutaneous phaeohyphomycosis has been increasing. Among them, members of the genera Alternaria, Bipolariz, Curvularia, Exophiala, Phialophora and Wangiella are the most common species. Despite the morphological differences among species, the illnesses they produce have many common features. Subcutaneous phaeohyphomycosis has pigmenta-occurred with equal frequency in tropical, subtropical and temperate areas partly because of the opportunistic nature of its etiologic agents.ObjectiveTo investigate the pathogenicity of Cladosporium cladosporioides. This study was also to investigate the difference on the ultrastructure and pathogenicity of the Cladosporium cladosporioides and Cladosporium carrionii. Investigate the antifungal susceptibility characteristic to know if it is sensitive to common antifungal drugs.To report the test of heat-tolerance of Cladosporium cladosporioides ,Cladosporium carrionii ,Fonsecaea pedrosoi, Fonsecaea compactum, Phialophora verrucosa, Cladosporium carrionii Exophiala dermatitidis,Exophiala jeanselmei and Alternaria alternate. To know the microbiological characteristics of medically Cladosporium cladosporioides and as well as to provide reference for the diagnosis and treatment of Cladosporium cladosporioides infection. Investigate the antifungal susceptibility characteristic to know if it is sensitive to common antifungal drugs. To investigate the DNA polymorphism of saprophytes and pathogenicity of Cladosporium species and to find out the relationship between them. To study the different expressions of proteins between Cladosporium cladosporioides and Cladosporium carrionii. Methods and Results1. The pathogenicity of Cladosporium cladosporioides: The cell suspension of Cladosporium cladosporioides was inoculated into gaster-skin of normal and immunocompromised ICR(Institute of Cancer Research) mice. Histopathologic examination and fungal culture were performed on sacrified mice on 15th d,30th d,60nd d respectively after inoculation. The abscesses were developed at the inoculated sites in all experimental mice. The necropsy revealed no disseminated infection of Cladosporium cladosporioides in all the test mice.2. A comparative study was performed on the difference on the ultrastructure of the Cladosporium cladosporioides and Cladosporium carrionii. There are some differeces on the ultrastructure of the Cladosporium cladosporioides and Cladosporium carrionii. The cell wall of Cladosporium cladosporioides is prone to be more thicker and to be aging.3. In vitro antifungal susceptibility tests of the isolate performed according to NCCLS guidelines. To detect the susceptibility of fluconazol, itraconazole, terbinafine, ketoconazole, miconazole, bifonazole,econazole and nystatin against Cladosporium cladosporioides.Using M38-P method the strains of Cladosporium cladosporioides were studied .The media containing the fungi in the concentrations of (0.4～5)×106cfu/mL were incubated at 35℃for5~7days. The tested Cladosporium cladosporioides were highly susceptible to itraconazole, terbinafine, ketoconazole, miconazole, bifonazole,econazole and nystatin,but its poorly susceptible to fluconazol.4. Test the heat-tolerance of Cladosporium cladosporioides ,Cladosporium carrionii , Fonsecaea pedrosoi, Fonsecaea compactum, Phialophora verrucosa, Cladosporium carrionii ExopHiala dermatitidis,ExopHiala jeanselmei and Alternaria alternate. Our findings show that two of the eight strains(Exophiala dermatitidis and Alternaria alternate) has the peculiarity of heat-tolerance while the other six strains are not well tolerant to heat.5. The total DNA was extracted with GenTLETM DNA extraction kit, Random amplification of polymorphic DNA(RAPD) assay was used to study the fingerprinting of 18 strains. Of ten random primers used, three(primer1,4,5) gave good reaction. The sequences of them were: primer1: 5'-GAGCCCTCCA-3', primer4: 5'-GTCAGGGCAA-3', primer1:5'-CAGCACCCAC-3'.There were some degrees of variation and genetic similarities in RAPD patterns of 18 isolates, with interspecies and intraspecies variation and genetic similarities . But the isolates of the same species didn't show high genetic similarities. Saprobic Cladosporium cladosporioides located in the same group of dendrogram of some dematiaceous fungi with humanpathogenicity.6. Proteins isolated from the Cladosporium cladosporioides were separated by two dimensional (2-D)gel electrophoresis.It is not easy to get sharp separation figure of protein from Cladosporium cladosporioides regardless of condition of culture.ConclusionCladosporium cladosporioides is a kind of opportunistic fungus with relatively high virulence to skin but low virulence to viscera. According to our study, we conclude that it is feasible to compare the differences of Cladosporium cladosporioides from Cladosporium carrionii for diagnosis and treatment of phaeohyphomycosis.This also states that the pathogenicity of Cladosporium cladosporioides is a little poorer than that of the Cladosporium carrionii. In vitro susceptibility testing of each clinical isolate should be done.This finding is of some significance in guiding to determination of the species of these fungi and also for prevention and treatment of infections of dematiaceous fungi .It suggested that it is necessary to monitor the resistant strains in antifungal treatment. Local heat therapy may also be used for patients with subcutaneous phaeohyphomycosis, even though some of the etiologic phaeoid fungi possess considerable thermotolerance. These are some genetic similarities between some different species and strains, but no distinct characteristics are found between saprophytes and human-pathogens. Sharp separation figure of protein from Cladosporium cladosporioides should be studied.