| Objective: Schizophyllum is a kind of opportunistic pathogen,whichbelongs to Basidiomycotina,Hymenonycetes,Agaricales,schizophyllaceaeand Schizophyllum.Most of the clinical cases related to Schizophyllumare deep infection(especially respiratory tract infection).Since the first i-solation of Schizophyllum from the infected nails of onychomycosis pa-tients in 1950,no further reports have been found that Schizophyllumcaused onychomycosis.In addition,no case of Schizophyllum infectionof hair has been reported at home and abroad.Trichophyton mentagrophy-tes can invade the skin,nails and hair.It is a common pathogen ofonychomycosis and tinea capitis.The purpose of this study is to investigate the invasion of Schizophyllum to nails and hair by establishing invitro nail penetration model and improved hair perforation model,and toprovide guidance for clinical diagnosis and treatment,and to further im-prove the understanding of the pathogenicity of Schizophyllum.Methods: Schizophyllum was isolated from the sputum of a patientafter coronary artery bypass grafting and identified as Schizophyllum(No.s-003)by Institute of Microbiology,Chinese Academy of Sciences.The standard strain of Trichophyton mentagrophytes was purchased from thefungal Laboratory of the Peking University First Hospital.The nail andhair samples were provided by healthy people,and the hair samplescame from four different age groups(< 2 years old;2-13 years old;14-18 years old;> 18 years old).Nail penetration test : nail wax blockmodel was made and randomly assigned to Schizophyllum group and Trichophyton mentagrophyte group.Each model was placed in Sabouraud’s liquid medium.In the model,the bacteria suspension was dripped tomake the ventral side of the deck contact with the bacteria suspensionand the dorsal side contact with the medium.Each group was set upwith a positive control(the bacterial suspension was directly dripped in-to the liquid medium)and a blank control(the same amount of normal saline was dripped into the wax block model).The penetration time ofeach model was observed and recorded,and the difference of penetration time between the two groups was compared by relevant statisticalmethods.The damage degree of Schizophyllum and Trichophytonmentagrophytes to nails and the morphology of hyphae and spores wereobserved by scanning electron microscope.Improved hair perforation test:The hair samples of four age groups were divided into Sabouraud agarmedium,and the bacteria suspension was added to the hair samples,3drops for each hair.The blank control samples were added with the same amount of normal saline,and the culture medium was placed inthe incubator.3-34 days after inoculation,several hairs were taken everyday to observe whether there was perforation under the microscope and Record the time of hair perforation in each sample;the difference ofhair perforation time between different groups was compared by usingrelevant statistical methods;the damaged hair samples were observedunder the scanning electron microscope to compare the hair destructionby Schizophyllum and Trichophyton mentagrophytes.Results: Nail penetration test: Schizophyllum was able to penetrate the deck,the penetration time was 2(1,3)days,and the penetration time of Trichophyton mentagrophyte group was 4(4,5)days.There was significant difference in penetration time between the two groups(P < 0.01),and the penetration time of Schizophyllum was shorter than that of Trichophyton mentagrophytes.Under the scanning electron microscope,there were wide cracks between the keratinocytes on the deck damaged by Schizophyllum,and hyphae penetrated into them.On the back side,hyphae penetrated from the cracks,and some edges of keratinocytes cocked up,and gaps appeared between the cells.On the ventral side of the deck damaged by Trichophyton mentagrophytes,the keratinocytes were seriously eroded,and the surface of the cells was rough,similar to "honeycomb" and intercellular A wide fissure was formed,in which hyphae penetrated,flat keratinocytes were seen on the dorsal side,and spores were drilled out from below.Improved hair perforation test: until the end of the test,Schizophyllum was not observed to cause wedge-shaped defect of hair,but it could cause "brush like" change of hair edge.Comparing the hair perforation time of the same age group,between Schizophyllum and Trichophyton mentagrophytes,the four age groups all got P < 0.01.The hair perforation time of Schizophyllum in each age group was longer than that of Trichophyton mentagrophytes.In Schizophyllum group,there was significant difference in hair perforation time among different age groups,but there was no significant difference in further pairwise comparison among different age groups.In the Trichophyton mentagrophyte group,there was no difference in the time of hair perforation among different age groups.Under the light microscope,hyphae and spores were attached around the hair in the Schizophyllum group and Trichophyton mentagrophyte group.In the Schizophyllum group,the hair was slightly damaged,with "brush like" changes on the edge of the hair shaft and no wedge-shaped defects.In the Trichophyton mentagrophyte group,the hair was severely damaged,with "brush like" edges and typical wedge-shaped defects.Under the scanning electron microscope,in the hair damaged by Schizophyllum,longitudinal cracks were observed on the surface of hair shaft,the edge of pubescence was warped and broken,and the cortex of hair shaft was slightly damaged.The damaged hair of Trichophyton mentagrophytes was more serious.There was no obvious pubescence like structure on the surface of hair,and there were many "insect like" cavities in the hair shaft.Conclusions:1.Schizophyllum can penetrate the nail and make cracks or cavities appear between the keratinocytes..2.Schizophyllum can cause damage to hair.3.Under the scanning electron microscope,the damage degree of Schizophyllum to nail and hair was less than that of Trichophyton mentagrophytes. |
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