Tiña capitis por Microsporum gypseum, una especie infrecuente / Tinea capitis by Microsporum gypseum, an infrequent species

La tiña capitis es considerada la infección por dermatofitos más frecuente en los niños. Los agentes etiológicos varían con el tiempo y según la zona geográfica, aunque, normalmente, son dermatofitos de origen zoofílico y, en los últimos años, también dermatofitos antropofílicos. Se presenta un caso de tiña capitis inflamatoria en un niño de 6 años de edad causada por Microsporum gypseum, un hongo geofílico patógeno para humanos y animales. Las fuentes de infección humana son el suelo, los gatos, los perros y pequeños mamíferos. Esta especie es poco frecuente como causa de dermatofitosis en el hombre, descrita, sobre todo, en tiña corporis y, raramente, en tiña capitis. En el diagnóstico de tiña capitis, identificar la especie causal es un factor determinante para el tratamiento.

Tinea capitis is considered the most frequent dermatophyte infection in children. The etiological agents vary from time to time and by geographical area, although they normally are zoophilic dermatophytes and in the last years also anthropophilic species. We report a clinical case of inflammatory tinea capitis in a 6-year-old child caused by Microsporum gypseum, a geophilic fungus pathogenic to humans and animals. The sources of human infection are soil, cats, dogs and small mammals. This species is less frequent as a cause of dermatophytosis in humans, described mainly in tinea corporis and rarely in tinea capitis. In the diagnosis of tinea capitis identifying the causative species is a determinant of the treatment.

Evaluation of INNO-LiPA mycobacteria v2 assay for identification of rapidly growing mycobacteria

A total of 54 rapidly growing mycobacteria (RGM) isolated from patients attended in the two hospitals of Cádiz Bay (Spain) were selected during a seven-year-period (2000-2006) in order to evaluate the INNO-LiPA Mycobacteria v2 assay for mycobacterial identification, based on the reverse hybridization principle. The strains were cultured in Lõwenstein-Jensen and Middlebrook 7H9 media and identified to the species level by sequencing of the 16S rRNA, PCR-restriction enzyme analysis of the hsp65 gene, conventional tests and INNO-LiPA Mycobacteria v2 assay. By the molecular methods we identified a total of 12 different species: 23 Mycobacterium fortuitum, 11 M. chelonae, 10 M. abscessus, 2 M. senegalense, 1 M. alvei, 1 M. brumae, 1 M. mageritense, 1 M. mucogenicum, 1 M. neoaurum, 1 M. peregrinum, 1 M. septicum and 1 M. smegmatis. Fifty two strains (96.3 percent) were correctly identified by conventional techniques and 47 strains (87.0 percent) by INNO-LiPA Mycobacteria v2 assay. We find INNO-LiPA Mycobacteria v2 assay simple to perform but it provides few advantages in comparison with conventional methods and sometimes needs complementary tests to identify Mycobacterium fortuitum complex, M. chelonae complex and specific species due to the great heterogeneity in the RGM group.

Espondilodiscitis tuberculosa en Cádiz (España) durante diez años / Tuberculous spondylodiscitis. Report of six patients

Background: Tuberculous spondylodiscitis is relatively uncommon but represents the most common location of osseous tuberculosis. Aim: To describe clinical features, imaging studies and laboratory tests to establish the diagnosis in a group of patients living in Cádiz (Spain). Material and Methods: Retrospective analysis of medical records of patients with tuberculous spondylodiscitis diagnosed between 2000 and 2009. The diagnosis was based on microorganism recovery from vertebral samples obtained by imaging guided biopsies. Results: Six patients with positive Mycobac-terium tuberculosis cultures from vertebral samples, were identified (10 percent of extra-pulmonary tuberculosis). In only 2 patients the Ziehl-Nielsen stain was positive, and histology was compatible in 4 cases. Four patients were females, their mean age was 54.3 years and the mean duration of symptoms was 7.3 months. Three patients had lumbar location and a positive Mantoux test. A soft tissue abscess was present in 4 cases. None of these patients had neurological complications. The treatment with four tuberculostatic agents (isoniazid, rifampicin, pyrazinamide and ethambutol) was effective in 5 patients. Conclusions: Tuberculous spondylodiscitis may become a serious disease due to diagnostic and treatment delays. The main examinations to establish diagnosis are magnetic resonance imaging and biopsy with microbiological culture. Generally, antituberculous therapy is effective in this clinical situation.

Sensibilidad a los antimicrobianos de micobacterias de crecimiento rápido mediante el método E-test / Assessment of in vitro susceptibility to antimicrobials of rapidly growing mycobacteria by E-test

Background: Rapidly growing mycobacteria (RGM) are considered opportunistic pathogens. An increasing number of post traumatic or surgical infections are caused by these microorganisms. Aim: To determine the antimicrobial susceptibility of RGM using the E-test method. Material and methods: A total of 54 isolates of RGM was obtained from several clinical samples and selected for this study Strains were identified to the species level by phenotypic and biochemical characteristics, PCR-restriction enzyme analysis of the hsp65 gene (PRA) and sequencing of the 16S rRNA. Susceptibility was investigated by E-test to amikacin, cefoxitin, ciprofioxacin, clarithromycin, imipenem, quinupristin/dalfopristin, linezolid and tigecycline. Results: Twelve different species of RGM were identified: Mycobacterium fortuitum (23 strains), M chelonae (11), M abscessus (10), Msenegalense (2), Malvei (1), Mbrumae (1), Mmageritense (1), mucogenicum (1), M neoaurum (1), Mperegrinum (1), M septicum (1) y M smegmatis (1). All the strains were inhibited by low concentrations of amikacin and tigecycline. Susceptibility to cefoxitin, fluoroquinolones, clarithromycin, imipenem and linezolid was variable. All but two strains were resistant to quinupristin/ dalfopristin. Conclusions: Due to the uneven antimicrobial susceptibility of different species of RGM, an antimicrobial susceptibility test is mandatory for these microorganisms. The E-test method is well suited to determine minimum inhibitory concentrations.