Apophysomyces variabilis as an emerging pathogen in Mainland China.

BACKGROUND: Mucormycosis is a rare form of invasive, rapidly progressive and lethal opportunistic fungal infection caused by Mucorales. Although Rhizopus arrhizus (R. arrhizus) is the most commonly isolated Mucorales worldwide, infections caused by Apophysomyces variabilis (A. variabilis) are increasing. OBJECTIVES AND METHODS: We present a case of necrotizing fasciitis caused by A. variabilis in an immunocompetent woman. In order to further understand the characteristics of the strain isolated from the patient, we identified the strain through ITS sequencing, assessed the ability to tolerate salt concentrations and temperature conditions, in addition to performing in vitro drug susceptibility testing against common antifungal agents. RESULTS: The strain showed 98.76% identity with A. variabilis in the NCBI database, and it was found to tolerate higher temperatures and salt concentrations than previously reported strains. The strain was sensitive to amphotericin B and posaconazole, but not to voriconazole, itraconazole, 5-fluorocytosine and echinocandins. CONCLUSIONS: This case indicates that Mucorales caused by A. variabilis should be recognised as an emerging pathogen that can cause a high mortality rate in the absence of prompt diagnosis and proper treatment in China, aggressive surgical debridement combined with prompt and appropriate antifungal treatment may improve outcomes.

Identification and validation of suitable reference genes for RT-qPCR analysis in mouse testis development.

RT-qPCR is a commonly used method for evaluating gene expression; however, its accuracy and reliability are dependent upon the choice of appropriate reference gene(s), and there is limited information available on suitable reference gene(s) that can be used in mouse testis at different stages. In this study, using the RT-qPCR method, we investigated the expression variations of six reference genes representing different functional classes (Actb, Gapdh, Ppia, Tbp, Rps29, Hprt1) in mice testis during embryonic and postnatal development. The expression stabilities of putative reference genes were evaluated using five algorithms: geNorm, NormFinder, Bestkeeper, the comparative delta C(t) method and integrated tool RefFinder. Analysis of the results showed that Ppia, Gapdh and Actb were identified as the most stable genes and the geometric mean of Ppia, Gapdh and Actb constitutes an appropriate normalization factor for gene expression studies. The mRNA expression of AT1 as a test gene of interest varied depending upon which of the reference gene(s) was used as an internal control(s). This study suggested that Ppia, Gapdh and Actb are suitable reference genes among the six genes used for RT-qPCR normalization and provide crucial information for transcriptional analyses in future studies of gene expression in the developing mouse testis.