Meirong Li

Disseminated infection caused by Emmonsia pasteuriana in a renal transplant recipient.

Emmonsia pasteuriana is a thermally dimorphic fungus identified in very few human cases. Here, we report a case of a 43‐year‐old male renal transplant patient from China presenting with multiple painful skin eruptions on his head, nose and left thigh, later accompanied by respiratory failure. Histopathology of the biopsy collected from the left thigh upper ulcer and occipital nodule both demonstrated chronic inflammation with granuloma formation and yeast‐like elements. Emmonsia pasteuriana was cultured from two biopsy specimens and their identity was confirmed by sequencing of the rDNA internal transcribed spacer. The patient in intensive care showed marked clinical improvement with antifungal treatment.

Substrate adaptation of Trichophyton rubrum secreted endoproteases

Trichophyton rubrum is the most common pathogen caused the dermatophytosis of nail and skin in human. The secreted proteases were considered to be the most important virulence factors. However, the substrates adaptation of T. rubrum secreted proteases is largely unknown. For the first time, we use the keratins from human nail and skin stratum corneum as the growth medium to investigate the different expression patterns of T. rubrum secreted endoproteases genes. During grow in both keratin-containing media SUB7 and MEP2 were the highest expressed gene in each family. These results indicated that SUB7 and MEP2 may be the dominant endoproteases secreted by T. rubrum during host infection and the other proteases may play a supplementary role. The direct comparison of T. rubrum grown on skin and nail medium showed different substrate favorite of secreted endoproteases. The genes MEP2, SUB5, SUB2 and SUB3 were more active during growth in skin medium, possibly these proteases have a higher affinity for skin original keratins. While the structures of SUB1, SUB4, and MEP4 maybe more suitable for the degradation of nail original keratins. This work presents useful molecular details for further understanding the pathogenesis of secreted proteases and the wide adaptation of T. rubrum.

Trichophyton rubrum conidia modulate the expression and transport of Toll-like receptor 2 in HaCaT cell.

Trichophyton rubrum (T. rubrum) represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that T. rubrum can modulate the innate immune responses of host cells, which result in the failure of host cells to recognize T. rubrum and initiate effective immune responses. In this study we show how T. rubrum conidia modulate the expression and transport of Toll-like receptor 2 in HaCaT cell. Flow cytometric analysis showed that the surface and total expression of Toll-like receptor 2 were upregulated at the very early stage when keratinocytes were exposed to T. rubrum conidia regardless of the dose, and the upregulation of surface TLR2 was much more significant than that of total TLR2. Moreover, TLR2 expression was suppressed after upregulation in the initial stage of T. rubrum exposure, and the decrease of total TLR2 was earlier than that of surface TLR2. Our results suggest that in the early stage, TLR2 of keratinocytes were upregulated and transported to the cell surface. After then, the expression of TLR2 was suppressed by T. rubrum conidia.

Effect of Culture Supernatant Derived from Trichophyton Rubrum Grown in the Nail Medium on the Innate Immunity-related Molecules of HaCaT

Background:Trichophyton rubrum is superficial fungi characteristically confined to dead keratinized tissues. These observations suggest that the soluble components released by the fungus could influence the host immune response in a cell in contact-free manner. Therefore, this research aimed to analyze whether the culture supernatant derived from T. rubrum grown in the nail medium could elicit the immune response of keratinocyte effectively. Methods:The culture supernatants of two strains (T1a, TXHB) were compared for the &bgr;-glucan concentrations and their capacity to impact the innate immunity of keratinocytes. The &bgr;-glucan concentrations in the supernatants were determined with the fungal G-test kit and protein concentrations with bicinchoninic acid protein quantitative method, then HaCaT was stimulated with different concentrations of culture supernatants by adopting morphological method to select a suitable dosage. Expressions of host defense genes were assessed by quantitative polymerase chain reaction after the HaCaT was stimulated with the culture supernatants. Data were analyzed with one-way analysis of variance, followed by the least significant difference test. Results:The T. rubrum strains (T1a and TXHB) released &bgr;-glucan of 87.530 ± 37.581 pg/ml and 15.747 ± 6.453 pg/ml, respectively into the media. The messenger RNA (mRNA) expressions of toll-like receptor-2 (TLR2), TLR4, and CARD9 were moderately up-regulated in HaCaT within 6-h applications of both supernatants. HaCaT cells were more responsive to T1a than TXHB. The slight increase of dendritic cells-specific intercellular adhesion molecule 3-grabbing nonintegrin expression was faster and stronger, induced by T1a supernatant than TXHB. The moderate decreases of RNase 7, the slight up-regulations of Dectin-1 and interleukin-8 at the mRNA level were detected only in response to T1a rather than TXHB. After a long-time contact, all the elevated defense genes decreased after 24 h. Conclusion:The culture supernatant of T. rubrum could directly and transiently activate the innate immune response of keratinocytes.

A case of chromoblastomycosis by Fonsecaea nubica indicating a possible insect route of transmission

A first auricular case of chromoblastomycosis due to Fonsecaea nubica is reported in a 42‐year‐old Chinese male. He presented a slightly verrucous, erythematous plaque on his right auricle which had gradually extended over a 10‐year period, and the patient reported a history of dog flea sting before onset of the lesions. Diagnosis was based on histopathological and mycological examination of clinical samples, which revealed muriform cells. Identification of the aetiological agent was assessed by morphological characteristics and confirmed at species level by sequencing of the rDNA internal transcribed spacer (ITS). The patient showed marked clinical improvement after 3 months combination therapy with itraconazole and terbinafine. The possible mode of transmission of auricular chromoblastomycosis is discussed.

Onychomycosis secondary to onychomadesis: an underdiagnosed manifestation

Onychomycosis is a rare nail disorder in early childhood, while onychomadesis is a periodic idiopathic, non‐inflammatory disease that affects the nail matrix and is common in children especially in those who suffer from viral infections. In this study, we investigated recent cases of onychomycosis subsequent to periods of onychomadesis in children. Sixteen young children (six males, 10 females) with a mean age of 36.5 months were diagnosed with onychomadesis, and 13 of the patients had a history of viral infection prior to nail changes. Direct microscopy of nail scaling was positive in 11 cases (68.8%), and culture was positive in the same number of cases. Four Candida species were isolated: Candida glabrata was the most frequent, found in eight cases (72.7%), while C. albicans, C. parapsilosis and C. tropicalis, each were encountered in a single case. All children were treated successfully with or without topical bifonazole therapy.

Prevalence of low inflammatory tinea genitalis in southern China

Emergence of highly inflammatory genital dermatophyte infections has been reported from Southeast Asia. In view of this, knowledge of the non‐outbreak fungal flora of the genitals is required as a baseline study.

Neonatal Cutaneous Invasive Aspergillosis Accompanied by Hemophagocytic Lymphohistocytosis

We describe a 6-week-old female infant with cutaneous invasive aspergillosis accompanied with hemophagocytic lymphohistocytosis. Aspergillus flavus was isolated from biopsies of necrotic skin lesions on the forehead and scalp; morphologic identification was confirmed by molecular analysis. In vitro antifungal susceptibility testing showed that amphotericin B and triazoles had potent activity. The patient responded well to treatment with intravenous amphotericin B combined with oral posaconazole and local wound care. The hemophagocytic lymphohistocytosis abated after treatment of cutaneous aspergillosis. Both cutaneous invasive aspergillosis and hemophagocytic lymphohistocytosis are severe disorders with high morbidity and mortality requiring prompt diagnosis and treatment.