Urinary Tract Infections Caused by Fluconazole-Resistant Trichosporon japonicum in 2 Kidney Transplant Patients and Analysis of Their Homology

High-throughput sequencing and characterization of potentially pathogenic fungi from the vaginal mycobiome of giant panda (Ailuropoda melanoleuca) in estrus and non-estrus

Introduction

The giant panda (Ailuropoda melanoleuca) reproduction is of worldwide attention, and the vaginal microbiome is one of the most important factors affecting the reproductive rate of giant pandas. The aim of this study is to investigate the diversity of vaginal mycobiota structure, and potential pathogenic fungi in female giant pandas during estrus and non-estrus.

Methods

This study combined with high-throughput sequencing and laboratory testing to compare the diversity of the vaginal mycobiota in giant pandas during estrus and non-estrus, and to investigate the presence of potentially pathogenic fungi. Potentially pathogenic fungi were studied in mice to explore their pathogenicity.

Results and discussion

The results revealed that during estrus, the vaginal secretions of giant pandas play a crucial role in fungal colonization. Moreover, the diversity of the vaginal mycobiota is reduced and specificity is enhanced. The abundance of Trichosporon and Cutaneotrichosporon in the vaginal mycobiota of giant pandas during estrus was significantly higher than that during non-estrus periods. Apiotrichum and Cutaneotrichosporon were considered the most important genera, and they primarily originate from the environment owing to marking behavior exhibited during the estrous period of giant pandas. Trichosporon is considered a resident mycobiota of the vagina and is an important pathogen that causes infection when immune system is suppressed. Potentially pathogenic fungi were further isolated and identified from the vaginal secretions of giant pandas during estrus, and seven strains of Apiotrichum (A. brassicae), one strain of Cutaneotrichosporon (C. moniliiforme), and nine strains of Trichosporon (two strains of T. asteroides, one strain of T. inkin, one strain of T. insectorum, and five strains of T. japonicum) were identified. Pathogenicity results showed that T. asteroides was the most pathogenic strain, as it is associated with extensive connective tissue replacement and inflammatory cell infiltration in both liver and kidney tissues. The results of this study improve our understanding of the diversity of the vaginal fungi present in giant pandas and will significantly contribute to improving the reproductive health of giant pandas in the future.

Identification of Clinical Trichosporon asteroides Strains by MALDI-TOF Mass Spectrometry: Evaluation of the Bruker Daltonics Commercial System and an In-House Developed Library

Trichosporon asteroides is an emerging yeast-like pathogen commonly misidentified by commercial biochemical identification systems. We evaluated the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the identification of 21 clinical T. asteroides strains using the Bruker Daltonics database (BDAL) and an in-house developed library. Mass spectra were obtained by the FlexControl system v.3.4, and characterizations were performed in the Biotyper BDAL database v.4.1 and the developed in-house library. Species identification for T. asteroides failed as all 21 strains were misidentified as T. japonicum (log-scores 1.89-2.19). Extending the existing database was crucial to achieving 100% correct species-level identification and accurate distinction between species. Our results indicate that the commercial BDAL database has no discriminatory power to distinguish between T. japonicum and T. asteroides. Whereas improvement of the current BDAL database is pending, we strongly advise system users not to exclude the possibility of the failure to report T. asteroides.

Pericardial Effusion Due to Trichosporon japonicum: A Case Report and Review of the Literature

Invasive infections due to Trichosporon spp. are life-threatening opportunistic fungal infections that may affect a wide array of organs. Here, we described a case of pericardial effusion due to Trichosporon japonicum in a 42-year-old female after a heart transplantation. T. japonicum was isolated from the pericardial fluid, pericardial drain hole and the swab of the sternal surgery scar wound. The late mycological diagnosis due to blood culture negative, the ineffective control of pulmonary bacterial infection and the late start antifungal therapy were the contributing factors in the patient’s death.

Processing human urine and ureteral stents for 16S rRNA amplicon sequencing

Ureteral stents are commonly used medical devices that harbor a unique and patient-specific microbial community. This protocol describes an optimized procedure for high-quality DNA extraction from both urine and ureteral stent samples for the purpose of downstream microbiota characterization by amplicon sequencing. Detailed instruction is provided for 16S rRNA gene V4 region sequencing with the Illumina platform, which enables accurate and reproducible microbiota profiling of low bacterial abundance urine and stent samples.

For complete details on the use and execution of this protocol, please refer to Al et al. (2020).

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The urinary tract harbors low-abundance microbiota capable of influencing health

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Traditional sample preparation yields variable results vulnerable to contamination

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Protocol optimizes urological specimen processing for 16S rRNA amplicon sequencing

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The method ensures high-quality, reproducible urological microbiota data generation