Examination Of Hair Perforation In Vitro And Observation By Scanning Electron Microscope On Geotrichum.

Objective: Geortichum sivcioal, a new srtain in Geolrichum,was first isolated from Brazil fly and Indian oak silkworln in 2002.Then it was isolated from a children,s kerion一like lesions and a Patient,s blood suffered with toxic ePidermal necrolysis one after anotherin our department.The examination of Hair Perforation in Vitro of the skin isolation has been Partly studied.In o ur research,on the one hand,.we observe the degree of the hairs damaged by Geotrichum and morpholgy of Geotrichum around the hairs by light microscope and scanning electron microscope (SEM). Which can help clinical docters to establish diagnosis on the infection of Geotrichum .O n the other hand,to compare the differences in the duration needed for Geotrichum Silvicola isolated from the skin lesion and blood and Geotrichum candidumn to damage hairs of diferent age groups.Then to analyse different invasiveness of Geotrichum.to hair.Methods: We collected healthy hairs of four diferent age groups (less than 2 years old,2～13 years old,13～19 years old and older than 19 years old) ,and performed hair perforation test In vitro .The isolated strains suspensions of Geotrichum Silvicola isolated from the skin lesion and blood and Geotrichum candidumn, incubated respectively on the surface of the hair on Sabourd agar at 37℃and incubated hairs were observed every day until we discovered the injurys of hairs ,about after eight to ten weeks.The damage to the hairs was observed under light microscope(L M) and by scanning electron microscope ( SEM). By way of statistics ,we compared the differences in the duration needed for the three fungi to damage hairs of diferent age groups.Results: We compared the differences of Geotrichum Silvicola isolated from the skin lesion and blood and Geotrichum candidumn in the damage to the hairs of diferent age groups. The criteria was that the hyphas and spores attached the damaged hairs. Between Geotrichum Silvicola and Geotrichum candidumn ould lead to d amage the hairs.1 seen from light microscope Hair's rim turned to be alike hairbrush greatly. It was clear that the surface on hairs was wedge-shaped damaged . In more serious cases,the hairs become accidented .There are a lot of roundness or elliptic or rodlike spores and a large amount of rectangle arthrospore, spores with monopole buddings and clamydospore arond hairs damaged by Geotrichum Silvicola.2 seen by SEM The damage to hairs by Geotrichum Silvicola is more severe than Geotrichum candidumn. Moreover the damage to hairs by Geotrichum Silvicola isolated from blood is the most severe in these three fungi .It was seen that the hypha of Geotrichum candidumn was entwined round the hair,making the hair cuticle arrange sloppy or some fall off mildly. While the hypha of Geotrichum Silvicola corrode cortex seriously and leading to a lot of hair cuticle damaged .What we can see is some coloboma on the hair's surface. The hypha of Geotrichum Silvicola isolated from blood can cause the hairs splited and medulla damaged.3 The time of Geotrichum Silvicola leading to damage the hairs was shorter than that of Geotrichum candidumn in diferent age groups (p<0.05). The time to damage the hairs was delayed along with the ages growing both in Geotrichum Silvicola and Geotrichum candidumn (p<0.05). Except the diversity between groups (less than 2 years old and 2～13 years old)had no s tatistical significance,the diversity among the other groups had statistical significance. The time and degree damaged by Geotrichum Silvicola were earlier and severer than Geotrichum candidumn.Conclusion:1 Both Geotrichum Silvicola and Geotrichum candidumn.can lead to hair perforation in vitro.2 The time and degree damaged by Geotrichum Silvicola were earlier and severer than Geotrichum candidumn 3 The time of Geotrichum Silvicola isolated from blood leading to damage the hairs was shorter than that of other two fungi4 The younger the age, the more easily the hairs damage.