Prevalence of Mycobacterium avium and Mycobacterium tuberculosis in blood cultures of Brazilian AIDS patients after introduction of highly active retroviral therapy

The use of highly active antiretroviral therapy (HAART) for the treatment of HIV infection has been associated with a marked reduction in the incidence of most opportunistic infections. From April 2001 to February 2002, 80 blood samples from patients who were suspected to have disseminated mycobacterial infection, presenting fever and (preferably) a CD4 T cell count < 100.0 cell/mL were investigated. Twelve (15 percent) of the 80 blood cultures were positive for mycobacteria, with Mycobacterium avium being identified in 7 (8.8 percent) samples and M. tuberculosis in 5 (6.2 percent). The TCD4+ count at the time of M. avium bacteremia ranged from 7cells/æL (average of 48.5 cell/æL), while in M. tuberculosis bacteremia it ranged from 50.0 cells/æL (average of 80.0 cell/æL). The prevalence of M. avium bacteremia in our study follows the expected decline in opportunistic infections observed after the introduction of HAART; however, mycobacteremia by M. tuberculosis still indicates a high prevalence of tuberculosis infection in AIDS patients.

Prevalence of Mycobacterium avium and Mycobacterium tuberculosis in blood cultures of Brazilian AIDS patients after introduction of highly active retroviral therapy.

The use of highly active antiretroviral therapy (HAART) for the treatment of HIV infection has been associated with a marked reduction in the incidence of most opportunistic infections. From April 2001 to February 2002, 80 blood samples from patients who were suspected to have disseminated mycobacterial infection, presenting fever and (preferably) a CD4 T cell count < 100.0 cell/mL were investigated. Twelve (15%) of the 80 blood cultures were positive for mycobacteria, with Mycobacterium avium being identified in 7 (8.8%) samples and M. tuberculosis in 5 (6.2%). The TCD4+ count at the time of M. avium bacteremia ranged from 7 cells/microL (average of 48.5 cell/microL), while in M. tuberculosis bacteremia it ranged from 50.0 cells/microL (average of 80.0 cell/microL). The prevalence of M. avium bacteremia in our study follows the expected decline in opportunistic infections observed after the introduction of HAART; however, mycobacteremia by M. tuberculosis still indicates a high prevalence of tuberculosis infection in AIDS patients.

Efficient method for mycobacterial DNA extraction in blood cultures aids rapid PCR identification of Mycobacterium tuberculosis and Mycobacterium avium.

The study presented here evaluated the utility of several methods of extracting mycobacterial nucleic acids from positive blood culture samples and examined the effect of each method on the performance of an in-house PCR used directly in the peripheral blood of 80 patients with AIDS to identify Mycobacterium spp. The modified Boom method for extracting DNA from blood cultures proved to be the most efficient, with subsequent PCR analysis yielding 100% positivity (7 samples positive for M. avium and 5 for M. tuberculosis). Only three of 12 patients with a positive blood culture had a PCR result positive for M. avium in peripheral blood. The identification of mycobacteria by PCR in blood culture took about 3 days, reducing the time to diagnosis by several weeks. These results demonstrate that PCR is a sensitive and quick method for identifying mycobacteria, especially when a good DNA extraction method is applied.

Incidência de S aureus Meticilino-resistente (MRSA) em estetoscópios de uso hospitalar / Methicillin-resistant (MRSA) S aureus

Foram colhidas prospectivamente 150 amostras para cultura de microrganismos de estetoscópios utilizados rotineiramente no hospital por acadêmicos de Medicina, médicos e enfermeiros. Realizou-se in print direto do diagragma e swab das reentrâncias dos estetoscópios em meio de cultura ágar-sangue. Os germes foram identificados através das provas padrões. A resistência à oxacilina/meticilina foi identificada por antibiograma através do método de Kirby-Bauer e semeadura em spot. Neste estudo os estetoscópios demonstraram ser reservatórios de agentes infecciosos, demonstrando bactérias em 91,3 por cento deles. A incidência em médicos, acadêmicos e enfermeiros foi, respectivamente, 87,9 por cento, 89,3 por cento e 97,7 por cento, nos diafragmas, e 96,5 por cento, 91,3 por cento e 75 por cento, respectivamente, nas reentrâncias. Entre os estafilococos presentes, 7,3 por cento eram meticilino-sensíveis e 2 por cento eram meticilino-resistentes no diafragma, e 5,3 por cento meticilino-sensíveis e 1,3 por cento meticilino-resistentes nas reentrâncias. Os autores sugerem a desinfecção do diafragma com álcool a 70 por cento antes do atendimento de cada paciente para evitar a possível disseminação destes germes