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In recent years , fungal biofilms related infection have become an increasingly important clinical problem .Many clinically important fungi can form biofilms , including:Candida albicans , Cryptococcus neoformans , Rhodotorula species , Aspergillus fumigatus, Malassezia pachydermatis, Histoplasma capsulatum.Many chronic persistent infections are associated with the fungal bio-film formation.The developmental phases of fungal biofilms are complicated , including adhesion, colonisation, maturation and dispers-al, which are governed by many genes .This review discusses clinical impact of biofilm formation of the common human pathogenic fun -gi, biofilm structure and the molecular mechanisms during the biofilm formation process .
ABSTRACT
Objective There have been a few reports on chronically recurrent and generalized superficial mycosis caused by trichophyton rubrum.This article was to investigate the cause, diagnosis and therapy of the mycosis. Methods 5 patients with chron-ically recurrent and generalized superficial mycosis caused by trichophyton rubrum were collected from June 2012 to June 2014 in our hospital.Bacterioscopic examination and cultivation were made on skin lesions of the patients.A typical patient who had 7-year course of desease with toenails seriously infected and widespread skin eruption was selected for histopathology examination on skin lesions, mi-crobiology and molecular biology study on 4 bacterial strains isolated from skin lesions in different parts, and in vitro chemosensitivity assay for drug selection.PCR (rDNA ITS sequence analysis) was performed for diagnosis and early treatment. Results Microscopic examintion on skin lesions demonstrated numerous septate, branched hyphae.Cultivation and molecular biology study identified tricho-phyton rubrum.The strain was identified as trichophyton rubrum by ITS sequence analysis and the isolated strains from different lesions were the same fungal species.Histopathology examination revealed slight hyperplasia of squamous epithelium , epidermal hyperkeratini-zation and the upper dermis presented a sparse perivascular lymphocytic infiltrate.The PAS-stain confirmed the presence of few hyphae in the horny layer.The pathogen of this case was trichophyton rubrum. A combination therapy with systemic itraconazole and topically applied terbinafine hydrochloride cream was successful.A follow-up examina-tion one year later showed no recurrence of symptoms. Conclusion The isolation and identification of pathogen is the key to the diagnosis of chronically recurrent and generalized superficial mycosis, with ad-ditional attention to all or none toenail infection.The therapy should not focus simply on the tinea corporis, while comprehensive treatment combined with chemosensitivity assay is preferred.
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Objective There is a lack of information on the effect of hypoxia on the virulence of Cryptococcus neoformans . This study was to construct a Cryptococcus neoformans bilfilm model in vitro and observe the influence of hypoxia on the biofilm forma-tion. Methods We constructed a Cryptococcus neoformans biofilm model in vitro in 24-well and 96-well microculture plates using DMEM culture medium at the oxygen concentrations of 21%( normoxia ) and 1% ( hypoxia ) .We collected the Cryptococcus neofor-mans biofilms at 2, 4, 8, 12, 24, 48, and 72 hours after culturing and observed their thickness , structure, and growth activity in the two different oxygen conditions by light microscopy , confocal laser scanning microscopy , and MTT assay . Results The Cryptococcus neoformans biofilm model was successfully constructed in the conditions of both hypoxia and normoxia .The processes of biofilm forma-tion in the two conditions were similar , involving adhesion , aggregation , micro-colony formation , and biofilm maturation , with the ulti-mate biofilm thickness of about 16 μm.The cell density and growth activity of the biofilms increased with the extension of incubation time, gradually stabilized with their maturity , and both were relatively higher at 1%than at 21%oxygen concentration . Conclusion The abilities of Cryptococcus neoformans biofilm formation vary with different oxygen concentrations , and hypoxia can promote the for-mation of Cryptococcus neoformans biofilms .
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Objective Candidas rank as the second factor of deep fungal infection .This study aimed to investigate the rela-tionship between Candidas and melanin by screening clinically isolated melanin -producing Candidas . Methods We incubated 360 strains of clinically isolated Candidas with caffeic acid , DOPA agar , and minimal medium at a temperature of 35℃, with Cryptococcus neoformans as the positive control .We observed the changes in the culture media using transmission electron microscopy (TEM) and electron spin resonance ( ESR) spectroscopy . Results Cryptococcus neoforman produced pigmentation in all the three types of medi -um.At 5 days, a standard strain of Candida albicans SC 5314 turned dark brown in the DOPA agar and minimal medium and , at 10 days, 12 and 15 of the 360 Candida strains turned dark brown in the DOPA agar and minimal medium , respectively, which were not shown to be melanin by TEM and ESR spectroscopy . Conclusion Culture media are not reliable enough for the identification of mel-anin-producing Candidas , and the observations need to be further verified by TEM and ESR spectroscopy .
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Psoriasis is a common disease , its pathogenesis is closely related with microorganism .Recent studies found that Malassezia spp.played an important role in the development and progression of psoriasis .In this article, we review the relationship be-tween psoriasis and Malassezia spp.from the aspects of clinical observation , therapeutics and immunological studies .
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Objective To investigate the effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) therapy on pulmonary hypertension,and its influence on number and functions of circulating endothelial progenitor cells (EPCs) in rats.Methods Eight week old Sprague-Dawlay rats were randomized into model group,treatment group and control group (8 rats in each group).The rats in model group and treatment group were treated with single subcutaneous injection of 1％ monocrotaline (50 mg/kg) to induce pulmonary hypertension models,while the control group was treated with phosphate buffered saline.Five days later,the rats in treatment group were administrated with 50 μg/(kg· d) rhG-CSF for 3 days.On day 21,peripheral blood was collected from caudal vein in all groups,and the percentage of EPCs in 100 000 mononuclear cells was evaluated by flow cytometry.Right ventricular systolic pressure was assessed,and the pathological changes of lung tissue and pneumoangiogram were observed by HE staining.Meanwhile,peripheral mononuclear cells collected from caudal vein were separated and cultured in vitro for EPCs.The cell ffunctions as proliferation,adhesion and migration ability were assessed.ANOVA and LSD test were applied as statistical analysis methods.Results (1) The right ventricular systolic pressure of rats in model group was higher than that in the controls [(48.13 ± 2.85) mm Hg vs (27.88 ± 3.04) mm Hg,t=2.016,P＜0.01],the lesion of endothelial cells in pulmonary arteriolar was evident,and the vessel wall was thickened.The pulmonary artery pressure of rats in the treatment group [(30.38 ± 2.83) mm Hg] was lower than that in the model group and close to the level of control group (t=0.376,P＞0.05) with mild pulmonary pathological changes.(2) The percentage off peripheral blood EPCs in mononuclear cells in the model group was decreased as compared to the control group [(0.016±0.007) ％ vs (0.031±0.011) ％,t=2.617,P＜0.01].After administration ofrhG-CSF,the EPCs in treatment group [(0.042±0.013) ％] was increased evidently as compared to the model group (t=4.325,P＜0.01) and the control group (t =1.942,P＜0.05).(3) The proliferation,adhesive and migrated cells of EPCs in model group were 0.49 ± 0.04,(6.93 ± 1.47) cells/HPF and (7.22±1.53) cells/HPF,lower than those in control group [0.68±0.07,(11.05±1.73) cells/HPF and (12.58±2.15) cells/HPF] and treatment group [0.63±0.06,(12.35±1.82) cells/HPF and (12.97±2.84) cells/HPF],the differences were statistically significant(all P＜0.05).Conclusions rhG-CSF may be effective in treating pulmonary hypertension through up-regulating the number and function of circulating EPCs in rat model of pulmonary hypertension.