Un caso inusual de quiste sebáceo infectado por Dermabacter hominis / Unusually infected sebaceous cyst by Dermabacter hominis

La especie Dermabacter hominis está constituida por bacilos gram positivos corineformes, anaerobios facultativos, que forman parte de la microbiota residente de la piel. Excepcionalmente se ha asociado a estos microorganismos con infecciones en pacientes inmunocomprometidos o muy debilitados. Se describe el caso de una mujer adulta joven, inmunocompetente, con un quiste sebáceo en el cuello, infectado por D. hominis como único agente etiológico. Se logró la identificación fenotípica del agente causal mediante pruebas simples basadas en el esquema originalmente propuesto por Funke y Bernard, factibles de ser realizadas en un laboratorio hospitalario de microbiología. Características fenotípicas como la morfología cocoide, el olor acre/espermático, la hidrólisis de la esculina, la producción de pirrolidonil arilamidasa y de lisina y ornitina descarboxilasas son pruebas claves en la identificación de D. hominis. La espectrometría de masas (MALDI-TOF MS) confirmó la identificación fenotípica.

Dermabacter hominis species is constituted by Gram positive facultative anaerobic coryneform rods being part of the resident microbiota human skin, and exceptionally associated to infections in immunocompromised or severely debilitated patients. An immunocompetent young adult woman with a neck sebaceous cyst infected by D. hominis as unique etiologic agent is presented. Phenotypic identification of the causative agent was achieved through simple tests, based on the originally scheme proposed by Funke and Bernard, and feasible to be performed in a hospital Microbiology Laboratory. Phenotypic characteristics as coccoid morphology, the acrid/spermatic odor, esculin hydrolysis, the production of pyrrolidonyl-arylamidase, lysine and ornithine decarboxylase, are key tests to identify D. hominis. The matrix-asisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) confirmed the phenotypic identification.

A Case of Misidentification of Dermabacter hominis as Listeria grayi / 대한임상미생물학회지

Listeria grayi is a catalase-positive, non-spore forming, and glucose-fermenting Gram-positive rod. L. grayi is widely distributed in environments such as soil, water and fresh food. Human infection by L. grayi is very rare, and there have been no cases reported in Korea, and only two cases worldwide. Dermabacter hominis is a relatively new species belonging to the coryneform bacteria and is a component of the normal human skin flora. D. hominis is a non-motile, glucose-fermenting, Gram-positive rod that has similar biochemical characteristics to L. grayi. The authors of the present study report a case initially misidentified as L. grayi via a traditional morphological and biochemical identification method but that was subsequently confirmed as D. hominis using sequence analysis of 16S rRNA.

A Patient with Fatal Septicemia Caused by a Rare Pathogen Dermabacter Hominis / 감염과화학요법

Dermabacter hominis (D. hominis) is a recently discovered gram-positive bacterial species, and it is usually recognized as an opportunistic human pathogen. Very few documented cases of severe infections caused by Dermabacter hominis have been published. In this report, we describe a case of fatal septicemia caused by Dermabacter hominis.