Mycobacterium avium complex (MAC) isolated from AIDS patients and the criteria required for its implication in disease

Anterior a pandemia de AIDS, o Complexo Mycobacterium avium (MAC) era responsavel pela maioria das vezes, por pneumopatias acometendo pacientes com doenca pulmonar cronica de base como enfisema e bronquite cronica. Em 1981, com o advento da sindrome de imunodeficiencia adquirida (SIDA), o MAC passou a representar mais uma das doencas bacterianas mais frequentes em pacientes com essa sindrome, sendo a doenca disseminada a principal forma de manifestacao clinica da infeccao. Entre Janeiro de 1989 e Fevereiro de 1991, no Setor de Microbacterias do Instituto Adolfo Lutz em Sao Paulo, o MAC foi isolado de 103 pacientes a partir do cultivo de diferentes especimes estereis processados coletados de 2.304 pacientes atendidos no Centro de Referencia e Treinamento AIDS e/ou Instituto de Infectologia Emilio Ribas...

[Purified protein derivatives prepared from Mycobacterium tuberculosis (PPDs) and M. intracellulare (PPD-B) in differential diagnosis of mycobacteriosis].

To reveal the possibility of differentiating diseases caused by M. tuberculosis and M. intracellulare, simultaneous tuberculin testing by PPDs and PPD-B was carried out among X-ray suspects of tuberculosis and health persons. PPD-B was prepared by Dr. Tasaka (Department of Bacteriology, Hiroshima University) from M. intracellulare (ATCC 13950). For tuberculin testing, 0.05 micrograms of PPDs from M. tuberculosis (Nihon BCG Co.) and 0.1 microgram of PPD-B were used. The study included 61 patients with disease caused by M. tuberculosis (TB), 23 patients with that of M. avium complex (MAC) and 40 healthy persons with no roentgenological abnormality (H). Forty healthy persons had been vaccinated with BCG. Statistical analysis of the diameter of reaction (redness) in each antigen in each group has been done by Boxplotting method. The results were as follows: (75% upper quartile point, median, 25% lower quartile point/mean +/- S. D.): PPDs in TB (41.8, 30.0, 19.0/32.0 +/- 17.7); PPD-B in TB (15.0, 10.5, 5.0/10.9 +/- 8.1); PPDs in MAC (26.0, 10.0, 7.0/16.4 +/- 13.9); PPD-B in MAC (20.5, 17.5, 12.5/19.1 +/- 11.4); PPDs in H (18.0, 12.0, 6.0/13.5 +/- 10.9); PPD-B in H (7.0, 2.8, 0.0/4.4 +/- 5.4). Mean of PPDs in TB patients and PPD-B in MAC patients were significantly (P less than 0.01) larger than those in other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of cellular fatty acids and proteins by capillary gas chromatography and sodium dodecyl sulphate polyacrylamide gel electrophoresis to differentiate Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum (MAIS) complex species.

Infections due to atypical mycobacteria have increased during the past 30 years. Species of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium scrofulaceum are among the most common non-tuberculous mycobacteria isolated from patients with AIDS or immunosuppressed. These three organisms are taxonomically closely related and identification, according to cultural characteristics and biochemical tests, is not always evident, so some of these related strains are grouped in a "MAIS" complex. Analysis of cellular constituents is an aid to identification. Gas chromatography was used to study mycolic acids and a secondary alcohol was found which is a discriminating constituent between M. scrofulaceum and the other two species. The lipidic analysis was not able to separate M. avium and M. intracellulare, so cell proteins were considered. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of proteins reflects genetic relatedness between strains; the different patterns obtained from these three species are described and it is shown that this method is very useful in classification and epidemiology.

Effect of Tween 80 on the growth of Mycobacterium avium complex.

The effect of Tween 80 on the growth of Mycobacterium avium complex (MAC) in liquid culture condition was investigated. Observation of the colony-forming units (CFU) and the morphology of MAC with transmission and scanning electron microscopy showed that Tween 80 at 0.05% in the medium (ca. 0.5 mg/ml) had bacteriostatic action and caused cell elongation. Tween 80 at 0.5% or more in the medium (ca. 5 mg/ml) reduced the quantity of MAC glycolipids and also led to false positive or positive results in biochemical tests for mycobacterial identification using nitrate reductase, urease, or arylsulfatase. To determine whether or not surfactants could reduce the MAC permeability barrier, the minimal inhibitory concentration (MIC) of antituberculosis drugs on MAC was determined in liquid medium with or without several kinds of surfactants including Tween 80. Five surfactants including Tween 80 increased the activity of antituberculosis drugs to MAC. These findings suggest that Tween 80 acts directly on the cell wall of MAC.

Two-dimensional gas chromatography with electron capture detection for the sensitive determination of specific mycobacterial lipid constituents.

A method was developed for determining two characteristic mycobacterial lipid constituents, tuberculostearic acid (as its pentafluorobenzyl ester) and 2-eicosanol (as its pentafluorobenzoyl ester), by using gas chromatography with electron capture detection. A microprocessor-controlled column-switching system (two-dimensional gas chromatography) facilitated sample preparation and increased specificity. The usefulness of the technique was illustrated by its ability to reveal picogram amounts of tuberculostearate in a suspension of Mycobacterium leprae isolated from a naturally infected armadillo. Two-dimensional gas chromatography with electron capture detection may in some instances provide a convenient alternative to gas chromatography-mass spectrometry for use in demonstrating the presence of mycobacteria in a complex environment.

Characterization of total deoxyribonucleic acid of Mycobacterium paratuberculosis (ATCC 19698) and of M. avium complex (ATCC 25291) using restriction enzymes.

Total DNA was extracted from M. paratuberculosis (ATCC 19698) and from M. avium complex (ATCC 25291) cultivated on RVB-10 enriched liquid media. Restriction endonuclease analysis was conducted of Total DNA using 34 enzymes and DNA digestion profiles were compared. Fifteen enzymes revealed important differences between the two species. Two pairs of enzymes (EcoRII, BstNI) and (MboI, Sau3AI) provide evidence for the presence of dcmI and dam methylation in DNA of M. avium complex and M. paratuberculosis. The differences in DNA fragments of these two species could be of potential value in differentiating these clinically significant mycobacteria.