Plantas do cerrado brasileiro com atividade contra Mycobacterium fortuitum / Brazilian cerrado plants active against Mycobacterium fortuitum

Mycobacterium fortuitum é uma micobactéria de crescimento rápido, ubíquo na natureza e relacionada a micobacteriose de importância médica.Ela tem sido isolada de bacteremias, abscessos, endocardites, feridas cirúrgicas e traumáticas.De difícil tratamento, o bacilo é reconhecido na literatura como resistente inclusive aos medicamentos utilizados na terapêutica da tuberculose.O objetivo deste trabalho foi pesquisar extratos vegetais do Cerrado brasileiro com atividade contra M. fortuitum, empregando a técnica do Microplate Alamar Blue Assay (MABA) como método analítico.Dos 26 extratos testados frente ao M.fortuitum, o extrato apolar de Quassia amara (extrato diclorometanico) foi o que apresentou melhor resultado com valor de CIM de 62,5mg/mL seguidos pelos extratos apolares de Syngonanthus macrolepsis, Davilla elliptica, Turnera ulmifolia com CIM de 125g/mL.Para as mesmas plantas analisadas, utilizando-se agentes extratores polares (etanol e metanol), foram verificados CIM superiores a 500g/mL.Os valores foram semelhantes aos de extratos de outras plantas analisadas sendo considerados não promissores.

Rapid detection of multidrug-resistant Mycobacterium tuberculosis using the mycobacteria growth indicator tube (MGIT) system

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis has increased the need for rapid drug susceptibility tests, which are needed for adequate patient treatment. The objective of the present study was to evaluate the mycobacteria growth indicator tube (MGIT) system to detect multidrug-resistant M. tuberculosis strains. The MGIT system was compared with two standard methods (proportion and resistance ratio methods). One hundred clinical M. tuberculosis isolates [25 susceptible to isoniazid (INH) and rifampicin (RIF), 20 resistant to INH, 30 resistant to INH-RIF, and 25 resistant to INH-RIF and other drugs] obtained in the State of Säo Paulo were tested for INH and RIF susceptibility. Full agreement among the tests was found for all sensitive and all INH-resistant strains. For RIF-resistant strains results among the tests agreed for 53 (96.4 percent) of 55 isolates. Results were obtained within 6 days (range, 5 to 8 days), 28 days and 12 days when using MGIT, the proportion method and the resistance ratio methods, respectively. The MGIT system presented an overall agreement of 96 percent when compared with two standard methods. These data show that the MGIT system is rapid, sensitive and efficient for the early detection of multidrug-resistant M. tuberculosis

McFarland nephelometer as a simple method to estimate the sensitivity of the polymerase chain reaction using Mycobacterium tuberculosis as a research tool

Polymerase chain reaction (PCR) has been widely investigated for the diagnosis of tuberculosis. However, before this technique is applied on clinical samples, it needs to be well standardized. We describe the use of McFarland nephelometer, a very simple approach to determine microorganism concentration in solution, for PCR standardization and DNA quantitation, using Mycobacterium tuberculosis as a model. Tuberculosis is an extremely important disease for the public health system in developing countries and, with the advent of AIDS, it has also become an important public health problem in developed countries. Using Mycobacterium tuberculosis as a research model, we were able to detect 3 M. tuberculosis genomes using the McFarland nephelometer to assess micobacterial concentration. We have shown here that McFarland nephelometer is an easy and reliable procedure to determine PCR sensitivity at lower costs

Systemic mycobacterioses in AIDS patients as determined by blood cultures on biphasic medium

Bacteremia due to mycobacteria can occur in AIDS patients in whom a rapid diagnosis is extremely important in order to plan a therapeutic conduct. Blood culture of mycobacteria using a biphasic system was set up in the Regional Laboratories of the Adolfo Lutz Institute, SP (Campinas, RibeirÒo Preto, Santo AndrÚ, Santos, SÒo JosÚ do Rio Preto and Sorocaba). During a three year period (1994-97), 1521 blood samples were analyzed from 1336 AIDS patients, with CD4+ cell count < 100/ml, hematocrit < 30 and serum albumin concentration < 3.0 g/dl seen in regional outpatient clinics or as inpatients in hospitals. Of the blood samples examined, 9.9 were positive for mycobacteria. The predominant species was Mycobacterium avium complex (MAC) (53.8) followed by Mycobacterium tuberculosis (28.0). Mycobacterium xenopi was isolated in one case (0.8) and in the remaining 17.4 the mycobacteria isolated were not identified. The implementation of blood culture for mycobacteria in our Institute has permitted the laboratory diagnosis of mycobacterial infections, in addition to providing data on the frequency of disseminated mycobacterial disease in AIDS patients in the region.

Bacteriological and epidemiological aspects of the diagnosis of Mycobacterium tuberculosis as the etiological agent of menigitis

Difficulties facing bacteriological diagnosis of meningitis are frequent, specially those caused by mycobacteria. From 1983 to 1987 samples of cerebrospinal fluid (CSF) from 16,921 patients mainly from the Emílio Ribas Hospital, SP, with clinical signs of meningitis were examined at the Instituto Adolfo Lutz, SP. 2,951 of the patients were diagnosed as being cases of bacterial meningitis, 134 of which tuberculous meningitis (4.5 per cent). 40.2 per cent were individuals of age 0-4 years, 52.3 per cent over 14 years and 7.5 per cent of unknown age. Tuberculous meningitis was clinically suspected in 51.5 per cent of the cases, while in the remaining cases (48.5 per cent) it was detected mainly because of the routine investigation of mycobacteria in CSF. Considering that the laboratory does not always receive a request to analyze M. tuberculosis in CSF and that, in terms of public health, tuberculosis is still an important problem, a careful study of mycobacteria in suspect cases of meningitis is recommended.