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Objective To evaluate in vitro antifungal activities of five clinically common antifungal agents against Geotrichum silvicola,and to observe morphological changes of Geotrichum silvicola after treatment with terbinafine.Methods Five antifungal agents commonly used in clinic,including terbinafine (TER),amphotericin B (AmB),flucytosine (FC),fluconazol (FCZ) and itraconazole (ICZ),were tested in this study.According to the National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 document and relevant literatures,a susceptibility test was performed to determine the minimal inhibitory concentration (MIC) values of the five antifungal agents against G eotrichum silvicola.Scanning electron microscopy (SEM) was used to observe morphological changes of Geotrichum silvicola treated with different concentrations of TER.Results The MIC values against Geotrichum silvicola were as follows:TER,0.01 μg/ml;AmB,0.4 μg/ml;FC,2 μg/ml;FCZ,2.69 μg/ml;ICZ,0.25 μg/ml.Geotrichum silvicola was sensitive to TER,AmB,FC and FCZ,and sensitive to ICZ in a dose-dependent manner.SEM revealed that after TER treatment,the surface of Geotrichum silvicola became rough and shrinking with irregular defects and holes,and even gave a fragment-like appearance.Conclusions Among the five tested antifungal agents,TER shows the strongest activity against Geotrichum silvicola.Within a certain range,the higher the concentration of TER,the more serious the damage to Geotrichum silvicola.
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Objective To discuss the specific role of association rules in the compatibility of herbs and the relationship between herbs and symptoms by analyzing ancient analogous prescriptions Zhizichi Decoction with SQL Server software.Methods The prescriptions which contain Gardenia and Semen Sojae Preparatum were searched in the database of “Ancient Prescriptions for Epidemic Disease”, and they were imported to software with the standardized data of their symptoms and ingredients, then the proper association rules were found. The laws between parameter setting and rule generation were searched through parameter adjustment.Results Many laws of the drug compatibility and relationship between herbs and symptoms were obtained effectively in data mining by adjusting the parameters:The support setting was good for finding common used drug compatibility, and the confidence was good for finding specific drug compatibility and relationship between herbs and symptoms;the item set which had high frequency, sometimes made the rule’s importance low.Conclusion The laws of compatibility of herbs and the relationship between herbs and symptoms for data mining of analogous prescriptions are discovered by analyzing the support, confidence and importance of the association-rules and the clinical magnificence between symptoms and herbs.
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Objective To determine the degree of damage to hairs by Geotrichum, and to compare the difference in infection duration and intensity by Geotrichum silvicola isolates from skin lesions and blood and Geotrichum candidumn isolates between hairs from different age groups. Methods In vitro hair perforation test was carried out on the hairs from healthy individuals of different age groups. Scanning electron microscopy was performed to observe hairs perforated by Geotrichum silvicola isolates from skin lesions and blood as well as Geotrichum candidumn isolates. Results Both Geotrichum silvicola and Geotrichum candidumn isolates could perforate hairs. The time taken to perorate hairs was significantly different between isolates of Geotrichum silvicola from skin lesions, blood and Geotrichum candidumn in every age groups (all P ＜ 0.05).The Geotrichum silvicola isolates from blood perforated hairs in the shortest time (range: 53 - 64 days, mean:58.07 ± 3.15 days), followed by those from skin lesions (range: 57 - 66 days, mean: 61.05 ± 2.55 days), and Geotrichum candidumn (range: 61 - 74 days, mean: 67.11 ± 3.78 days). The time taken to perforate hairs by Geotrichum significantly increased with age, and significant difference was observed between hairs from the four age groups, i.e., ＜ 2 years, 2 - 13 years, 14 - 19 yeas, ＞ 19 years, but not between the age group of ＜ 2 years and that of 2 - 13 years (P ＞ 0.05 ). As scanning electron microscopy showed, both Geotrichum silvicola and Geotrichum candidumn could damage hairs, and the degree of damage by Geotrichum silvicola was more severe than that by Geotrichum candidumn. Conclusions The damage to hairs by Geotrichum silvicola is earlier and more severe than that by Geotrichum candidumn. The younger the age, the more liable the hairs to be damaged by Geotrichum.
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Objective To report a case of toxic epidermal necrolysis associated with geotrichosis due to Geotrichum silvicola. Methods The exudates from the body surface, blood and urine of the patient were examined by microscopy and simultaneously inoculated onto the Sabouraud dextrose agar (SDA) medium. The isolate was examined by microscopy, PCR which amplified the D1/D2 domain of 26S rDNA, and gene sequencing. Homologous sequences were searched in the GenBank/EMBL/DDBJ/PD nucleotide sequence library, and the genetic relationship was analyzed with the genealogical tree. Results Microscopy of pus from the abscess on the dorsa of left hand revealed a lot of spores and a few hyphae, which were not observed in the blood or urine specimens. Meanwhile, whitish colonies were grown in all the three successive cultures of blood and urine specimens, rather than the exudates on the body surface. After itraconazole and garlicin were administered for one week, both microscopic exam and fungus culture were negative. Microscopic exam of the isolate showed arthrospores arranged in chains, budding spores and a few of hyphae. It was found that there was a one-base difference between our isolate (Hebei-1) and the isolate from kerion -like eruptions (Changzheng-1), and a four-base difference between our isolate and the reference Geotrichum silvicola strain as well, in the D1/D2 domain of 26S rDNA. This isolate was identified to be most close to Changzheng-1 in the phylogenetic tree. Conclusion The patient with toxic epidermal necrolysis is associated with geotrichosis due to Geotrichum silvicola.
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Objective To report a case of kerion caused by Geotrichum in China. Methods A 9 year-old-boy had kerion-form lesion on his scalp with swollen posterior auricular lymph nodes, and did not show other definite underlying disease. The pathogenic fungus was identified according to culture, scanning electron microscopy, biochemical tests and DNA sequencing. The hair infection test was performed and the infected hairs were examined by scanning electron microscope. Animal test confirmed the pathogenicity of the fungus. Results The fungal colonies were the same when the tissue cultures were repeated. The colonies showed milky white to yellowish in color. The hyphae could be identified at the periphery on Sabouraud′s agar culture at 27 ℃, which were moist and smooth on the surface at 37 ℃. Under microscope, there were many rectangular arthrospores, round or oval spores with or without buddings, as well as branched hyphae. The isolated fungus was identified as a Geotrichum silvicola by culture, scanning electron microscope, biochemical test and DNA sequencing. The patient′s condition was improved markedly after treatment of terbinafine for 4 weeks. Conclusions This is the first case report of kerion caused by Geotrichum in China, and terbinafine is effective.