IS1245 restriction fragment length polymorphism typing of Mycobacterium avium from patients admitted to a reference hospital in Campinas, Brazil

Mycobacterium avium is an important pathogen among immunodeficient patients, especially patients with AIDS. The natural history of this disease is unclear. Several environmental sources have been implicated as the origin of this infection. Polyclonal infection with this species is observed, challenging the understanding of its pathogenesis and treatment. In the present study 45 M. avium strains were recovered from 39 patients admitted to a reference hospital between 1996 and 1998. Species identification was performed using a species-specific nucleic acid hybridization test (AccuProbe®) from Gen-Probe®. Strains were genotyped using IS1245 restriction fragment length polymorphism typing. Blood was the main source of the organism. In one patient with disseminated disease, M. avium could be recovered more than once from potentially sterile sites. Strains isolated from this patient had different genotypes, indicating that the infection was polyclonal. Four patient clones were characterized in this population, the largest clone being detected in eight patients. This finding points to a common-source transmission of the organism

In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients Atividade in vitro de minociclina sobre microrganismos superinfectantes isolados de pacientes com periodontite crônica

Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC) of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) and Candida spp. (n = 25) were included in the study. Minimal inhibitory concentrations (MIC) of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 &micro;g/mL, followed by Enterobacteriaceae with a MIC of 16 &micro;g/mL. The concentration of 16 &micro;g/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 &micro;g/mL. A concentration of 1,000 &micro;g/mL was not enough to inhibit 100% of the tested isolates.<br>Periodontite crônica é a forma mais comum de periodontite e está associada a diversas espécies de microrganismos. Enterobactérias, Pseudomonas, Staphyloccocus e Candida têm sido recuperados de bolsas periodontais de indivíduos com periodontite crônica e implicados em casos de superinfecção. A terapia antimicrobiana local ou sistêmica pode ser utilizada para reforçar os efeitos da terapia mecânica convencional, e a minociclina tem sido sugerida como antimicrobiano eficaz frente a periodontopatógenos. O objetivo deste trabalho foi avaliar a concentração inibitória mínima (CIM) de minociclina sobre microrganismos superinfectantes isolados de bolsas periodontais e cavidade bucal de indivíduos com periodontite crônica. Foram utilizadas 84 cepas de microrganismos, incluindo Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) e Candida spp. (n = 25). A CIM foi determinada pelo método de diluição em ágar Müeller-Hinton. Staphylococcus foram os microrganismos mais sensíveis a minociclina com CIM de 8 &micro;g/mL, seguidos por Enterobacteriaceae com CIM de 16 &micro;g/mL. Entre as espécies de Candida, 96% foram inibidas na concentração de 16 &micro;g/mL. Para 88,8% das cepas de Pseudomonas aeruginosa a CIM foi de 128 &micro;g/mL. A concentração de 1.000 &micro;g/mL não foi suficiente para inibir 100% das cepas testadas