Isolation and Characterization of an Atypical <i>Metschnikowia</i> sp. Strain from the Skin Scraping of a Dermatitis Patient

<div><p>A yeast-like organism was isolated from the skin scraping sample of a stasis dermatitis patient in the Mycology Unit Department of Medical Microbiology, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The isolate produced no pigment and was not identifiable using chromogenic agar and API 20C AUX. The fungus was identified as <i>Metschnikowia</i> sp. strain UM 1034, which is close to that of <i>Metschnikowia drosophilae</i> based on ITS- and D1/D2 domain-based phylogenetic analysis. However, the physiology of the strain was not associated to <i>M</i>. <i>drosophilae</i>. This pathogen exhibited low sensitivity to all tested azoles, echinocandins, 5-flucytosine and amphotericin B. This study provided insight into <i>Metschnikowia</i> sp. strain UM 1034 phenotype profiles using a Biolog phenotypic microarray (PM). The isolate utilized 373 nutrients of 760 nutrient sources and could adapt to a broad range of osmotic and pH environments. To our knowledge, this is the first report of the isolation of <i>Metschnikowia</i> non-<i>pulcherrima</i> sp. from skin scraping, revealing this rare yeast species as a potential human pathogen that may be misidentified as <i>Candida</i> sp. using conventional methods. <i>Metschnikowia</i> sp. strain UM 1034 can survive in flexible and diverse environments with a generalist lifestyle.</p></div

ITS- and D1/D2 domain-based phylogenetic analysis.

<p>Bayesian phylogram generated based on (A) ITS and (B) D1/D2 domain sequenced data. The tree is rooted with <i>Saccharomyces cerevisiae</i> as outgroup. Numbers on the nodes indicate Bayesian posterior probability based on 100 sampling frequency for a total of 500,000 and 100,000 generations for ITS and D1/D2 alignments, respectively.</p

The hyperpigmented, scaly, and lichenified patches over both feet with macerated toe web spaces.

<p>The hyperpigmented, scaly, and lichenified patches over both feet with macerated toe web spaces.</p

Colonial and microscopic morphology of <i>Metschnikowia</i> sp. strain UM 1034.

<p>(A) The surface of the colonial morphology of <i>Metschnikowia</i> sp. strain UM 1034 after being cultured for five days on SDA, V8, PDA, and CMA at 25°C. (B) Light micrograph showing the micromorphology of <i>Metschnikowia</i> sp. strain UM 1034 on SDA, V8, PDA, and CMA (400× magnification, bars 20 μm).</p

Chemical sensitivity of <i>Metschnikowia</i> sp. strain UM 1034.

<p>Conditions with a final Omnilog unit (at 60 hours) ≥ 20,000 were incorporated into the heat maps. The growth of <i>Metschnikowia</i> sp. strain UM 1034 in a respective substrate over the 60-hour incubation is represented by a color range, as given by the scale bar at the bottom of the figure.</p