Mycobacterium marinum infection simulating chromomycosis: a case report.

Skins infections caused by Mycobacterium marinum occur only rarely. We report one case of chronic and extensive M. marinum cutaneous infection simulating chromoblastomycosis and review the pertinent literature. A 52-year-old farmer reported a 32-year chronic skin problem on his right lower limb, resulting from contact with cacti. It consisted of skin lesion presenting with dyschromic atrophic center plate and verrucous borders with hematic crusts, extending from the knee anteriorly to the inferior third of the right leg. Mycobacterium marinum infection was detected by histopathological examination of a skin fragment, culture for mycobacteria and genetic mapping of the culture material. The patient was successfully treated with Ethambutol, Rifampicin and Trimethoprim-Sulfamethoxazole. The clinical and histopathological findings of M. marinum infection is nonspecific showing clinical polymorphism and bacilli are rarely evident on histopathological examination. Given these difficulties, it is essential to perform tissue culture in a suspicious case and it is important keep this infection in mind in patients with long-lasting indolent verrucous lesions and a history of exposure to sea water, freshwater, aquaria or fish.

Chronic cavitary pneumonia by Rhodococcus equi in a highly prevalent tuberculosis country: a diagnosis challenge.

Rhodococcus equi is a facultative aerobic, intracellular, non-motile, non-spore-forming, Gram-positive, weakly acid-fast coccobacillus belonging to the group of nocardioform actinomycetes. R. equi infections are rare opportunistic illnesses in patients with Acquired Immunodeficiency Syndrome (AIDS), associated with a high mortality rate. The most common clinical presentation of R. equi infections is a chronic cavitary pneumonia. Due to its acid-fastness, R. equi can be mistaken for others acid-fast organisms, as Mycobacterium tuberculosis. In turn, R. equi is also a gram-positive pleomorphic bacteria and can be mistaken for diphtheroids or Micrococcus organisms, being accidentally disregarded as oral contaminants in sputum cultures. Therefore, in Brazil, a highly prevalent tuberculosis (TB) country, pulmonary infections caused by R. equi may mimic pulmonary TB and represent a diagnostic challenge. Here, we report on a case of chronic cavitary pneumonia by R. equi in a Human Immunodeficiency Virus (HIV)-infected patient, focusing on diagnostic aspects.

Mycobacterium fortuitum-related lymphadenitis associated with the varicella-zoster virus.

Lymphadenitis caused by non-tuberculous mycobacteria is an uncommon manifestation in immunocompetent individuals. Here, we report a case of Mycobacterium fortuitum infection in a previously healthy 9-year-old patient who developed cervical lymphadenitis evolving to a suppurative ulcer associated with a varicella-zoster virus infection. We discuss the relationship between the varicella-zoster virus and the immune response of the host as an explanation for the unusual progression of the case.

Mycobacterium fortuitum-related lymphadenitis associated with the varicella-zoster virus

Lymphadenitis caused by non-tuberculous mycobacteria is an uncommon manifestation in immunocompetent individuals. Here, we report a case of Mycobacterium fortuitum infection in a previously healthy 9-year-old patient who developed cervical lymphadenitis evolving to a suppurative ulcer associated with a varicella-zoster virus infection. We discuss the relationship between the varicella-zoster virus and the immune response of the host as an explanation for the unusual progression of the case.

Prevalence of Subgingival Staphylococcus at Periodontally Healthy and Diseased Sites

Staphylococci are considered members of the transient oral microbiota and are seldom isolated from the oral cavity. The aim of this study was to establish the prevalence of subgingival staphylococci in healthy and periodontal disease sites. Sterile endodontic paper points were used to isolate subgingival staphylococci in periodontally healthy and periodontally diseased sites in 30 adult subjects (n=540 sites). Staphylococcus spp were identified by an automated method and confirmed by conventional biochemical tests. All the samples were identified as coagulase-negative staphylococci. The results were analyzed using Mann-Whitney U, chi-square and Fisher's exact test at 5% significance level. A total of 86.7% of the subjects harbored these microorganisms in 11.7% of their periodontal sites. The most frequently isolated species was S. auricularis, which was isolated from 31.4% of the periodontal sites, followed by S. epidermidis, isolated from 21.4% of them. There was no statistically significant difference between the frequencies of these species isolated either from the healthy and the diseased sites (p>0.153). Although staphylococci are present in the subgingival environment and contribute to the pathogenic synergism involved in periodontal diseases, the results suggest that they do not participate directly in the pathogenesis of these diseases.

Os estafilococos são considerados membros da microbiota oral transiente e são pouco isolados da cavidade oral. O objetivo deste estudo foi estabelecer a prevalência de estafilococos subgengivais em sítios saudáveis e com doença periodontal. Pontas endodônticas de papel absorvente estéreis foram usadas para isolar estafilococos subgengivais de sítios periodontais doentes e saudáveis, em 30 indivíduos adultos (n=540 sítios). Os Staphylococcus spp foram identificados por método automatizado e confirmados por provas bioquímicas convencionais. Todas as amostras foram identificadas como estafilococos coagulase-negativa. Os resultados foram analisados através dos testes de Mann-Whitney U, Qui-quadrado ou Exato de Fisher para um nível de significância de 5%. Um total de 86,7% dos indivíduos albergavam estes microrganismos em 11,7% de seus sítios periodontais. A espécie mais frequentemente isolada foi S. auricularis, a qual foi isolada em 31.4% dos sítios periodontais, seguida pela espécie S. epidermidis, isolada de 21.4% dos sítios. Não houve associação significativa na freqüência de isolamento das espécies, seja nos sitios periodontais saudáveis ou doentes (p>0.153). Embora os estafilococos estejam presentes no ambiente subgengival e contribuam para o sinergismo patogênico envolvido em doenças periodontais, sugere-se que eles não participem diretamente na patogênese destas doenças.