SUMMARYThe physiological properties of 229 strains of mycobacteria (photochromogens, scotochromogens, non-photochromogens and rapid growers) and others already classified were analysed. According to their metabolic capacities and using the method proposed by Sneath, three branches were established.Branch I is formed by micro-organisms with a high metabolic capacity and rapid rate of growth. Neotype strains of old species are proposed and holotypes of the new species are designated. A key for the identification of these species and a taxonomic tree of mycobacteria are described.
The biological properties of ribosomal proteins of Wocardia asteroides and W. brasiliensis were studied. These proteins elicited delayed-type hypersensitivity in .Nocardia-sensitized gulnea-pigs, as well as inhibition of macrophage migration in the peritoneal exudate obtained from the sensitized animals. The delayed reactivity was heat resistant but it was destroyed by treatment with pronase.
Two immunologically active polysaccharides were isolated from Nocardia asteroides (Poly I Na and Poly II Na) and N. brasiliensis (Poly I Nb and Poly II Nb). These polysaccharides were isolated from cell extracts and purified by methanol precipitation, chloroform extraction of extraneous material, and deproteinization with trichloroacetic acid. The crucial step used for separation of Poly I and Poly II from both nocardias was differential solubility. From dried preparations containing both polysaccharides, Poly I was solubilized at pH 10, whereas Poly II remained insoluble and was subsequently solubilized at pH 5. Poly I Na and Poly I Nb are apparently the same. Arabinose and galactose were the monosaccharide constituents of these polysaccharides, and their molar ratios were similar. Furthermore, PolW I Na and Poly I Nb crossreacted in agar diffusion precipitin tests with rabbit antisera prepared against either N. asteroides or N. brasilies. Either polysaccharide absorbed serum antibodies against the other. These polysaccharides can be regarded as groupspecific. Poly II Na and Poly II Nb are different and species-specific. They are composed of arabinose, galactose, and mannose but exhibit different molar ratios of these sugars according to species. They reacted only with homologous antisera.
A precise demonstration of the presence of circulating antibodies in patients with mycetoma due either to Nocardia brasiliensis or Nocardia asteroides is lacking. Laboratory animals immunized with these microorganisms show antibodies in their blood, as revealed by agglutination, precipitation or complement fixation reactions( 1-3) ; however, all of these lacked the requisite specificity.The literature also contains contradictory reports regarding skin hypersensitivity studies carried out with these microorganisms (4-8).The materials* used to elicit responses have been likewise, crude and non-quantitative.This paper is concerned with the immunological response of patients with mycetoma due to N . brasiliensis, using purified Nocardia polysaccharides as antigens for serology, and purified Nocardia proteins to evoke skin reactions.Materials and methods. Serological tests were carried out using Ouchterlony's( 10) double-diff usion precipitin reaction in agar. Sera from 14 patients with mycetoma due to N . brasiliensis were tested and compared with a number of sera from tuberculous patients, healthy individuals, as well as with sera from patients with other infectious and non-infectious diseases.As antigens for the precipitin reactions we used 2 polysaccharides isolated from N . brasiliensis (Poly I Nb and Poly I1 Nb) and 2 others from N . asteroides (Poly I Na and Poly I1 Na). Poly I Na and Poly I Nb are apparently the same and are regarded as group specific. Arabinose and galactose are the monosaccharide constituents of Poly I *Th: term "sensitin" has been suggested(9) for a nonantigenic substance prepared from a microorganism, capable of revealing sensitivity of the delayed type which is evoked by the organism. Tuberculin, histoplasmin and coccidioidin are regarded as examples of "sensitin".Nb and Poly I Na and their molar ratios are similar. They cross-react when tested with rabbit antisera prepared against either Nocardia species. Furthermore, either polysaccharide I absorbed serum antibodies against the other.Poly I1 Nb and Poly I1 Na are species specific; they react with rabbit antisera prepared against the homologous Nocardia species only. They contain mannose in addition to arabinose and galactose, with the molar ratios of the last 2 sugars variable according to species. A full account on the purification and the immunological characterization of these polysaccharides is being reported elsewhere ( 1 1 ) .Sera obtained from the patients had been preserved at 0°C after addition of merthiolate to a final concentration of 1:1O,OOO. Usually, 0.1 ml of serum was deposited in the center well of the agar plates, and 0.1 ml containing 50 pg of each of the purified polysaccharide antigens was placed in the peripheral wells. The plates were incubated at 2 1 "C for up to one week in a moist chamber. All precipitin bands that appeared were visible between 24-72 hours of incubation.Skin tests. For these tests we used purified protein derivatives from N . brasiliensis and from N . asteroides (RS-81). For comparison, a puri...
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