[Microanalytical methods: latex agglutination and immunoenzyme analysis in the diagnosis of meningococcal infection]. / Metody mikroanaliza: lateks-aggliutinatsiia i immunofermentnyi analiz v diagnostike meningokokkovoi infektsii.

Modified polystyrene latexes with high adsorption capacity, comparable to that of latexes produced by Difco Laboratories (USA), have been developed in the USSR. Diagnostic latex preparations for the detection of meningococci of serogroups A, C, Y and Haemophilus influenza, type b, prepared on the basis of these new latexes, have shown high specificity and sensitivity in experimental and clinical tests. The latex preparations for the detection of serogroup B meningococci requires further improvement. The use of latex preparations, together with other laboratory methods, in the diagnosis of meningococcal infection has promoted the etiological confirmation of the disease in 84% of cases; this method has proved to be 1.5 times more effective than the bacteriological one and not less sensitive than the enzyme immunoassay, while being more specific.

[Increased specificity of immunoenzyme analysis for diagnosing meningococcal infection]. / Povyshenie spetsifichnsoti immunofermentnogo analiza dlia diagnostiki meningokokkovoi infektsii.

The ELISA test system for the detection of polysaccharide antigens of meningococci, groups A and C, on the basis of the neutralization of specific antibodies has been developed. The specificity of this reaction is determined by the chemically pure preparations of group A and C meningococcal polysaccharides. The sensitivity of this test system based on the neutralization of antibodies is not inferior to that of ELISA with the use of double antiserum.

[Etiological diagnosis of suppurative bacterial meningitis today]. / Etiologicheskaia diagnostika gnoinykh bakterial'nykh meningitov v sovremennykh usloviiakh.

As the result of laboratory examination of 2165 patients with virulent bacterial meningitides, including cases of meningococcal infection, the etiological diagnosis was confirmed in 1407 patients (65.0%), the number of cases confirmed by the laboratory examination being significantly greater among adults than among children: 67.5 +/- 1.37% and 63.1 +/- 1.53%, respectively, (t = 2.1). Meningococcal infection was confirmed in 1111 (70.6%) out of 1572 patients under examination. Of the patients with purulent meningitides, pneumococcal etiology was determined in 27.4%, type b of Haemophilus influenzae in 13.5%, other infective agents in 10.0%. The comparison of the results obtained in the examination, carried out by different methods, of 946 children and 770 adults with meningococcal infection revealed a considerable difference in the number of positive results yielded by the bacteriological method and countercurrent immunoelectrophoresis (CIE). Among adults meningococci were isolated twice as frequently (41.1 +/- 2.5% - 19.4 +/- 1.6%), and the results yielded by CIE were predominantly positive (55.1 +/- 2.5% and 40.1 +/- 2.5%). CIE and the immunoenzyme assay were shown to have advantages in the diagnosis of the disease. Under the conditions of intensive antibiotic therapy the methods based on the detection of specific antigens in body fluids can greatly assist in diagnosis.

[Immunoenzyme method in the diagnosis of meningococcal infections]. / Immunofermentnyi metod v diagnostike meningokokkovoi infektsii.

The materials on the development and use of the test system, based on the enzyme-linked immunosorbent assay (ELISA) and intended for the detection of specific group A and C meningococcal polysaccharides and type b Haemophilus influenzae polysaccharide in the spinal fluid of patients, are presented. In this work commercial preparations manufactured in the USSR were used, and all parameters of the assay were developed on the basis of these preparations. The study was made on the samples of spinal fluid from 410 patients; of these, 203 had meningococcal infection, 57 had purulent bacterial meningitides and 150 had other diseases (acute respiratory diseases, influenza, etc.). As demonstrated by the results of this study, ELISA proved to be a highly specific and sensitive technique. In the investigation of the spinal fluid samples from the patients with meningococcal infection the use of ELISA with bacteriological techniques increased the number of positive results to 67%; with countercurrent electrophoresis, to 78%; and with bacterioscopy, to 83.8%. ELISA is recommended for practical use as an auxiliary laboratory technique and as a rapid method for the diagnosis of meningococcal infection.

[Surface antigen structure of Neisseria meningitidis. I. The isolation of a serotypic antigenic complex of N. meningitidis strain B16B6 by direct detergent treatment and its immunochemical characteristics]. / Poverkhnostnye antigennye struktury Neisseria meningitidis. Soobshchenie I. Poluchenie serotipovogo antigennogo kompleksa N. meningitidis shtamma B16B6 priamoi obrabotkoi detergentami i ego immunokhimicheskaia kharakteristika.

The method for obtaining a serotyping antigenic complex from N. meningitidis B16B6 by their direct treatment with the mixture of detergents (0.5% sodium desoxycholate and 0,5% cholic acid in the proportion 1 : 1) in 0.5 M KCl solution is proposed. Such treatment has been found to increase the yield of the preparation in terms of protein more than 4 times in comparison with earlier methods for obtaining serotyping antigens. The immunochemical study of the preparation has demonstrated its serological specificity and high immunological activity, not inferior to that of serotyping antigenic preparations from group B meningococci, obtained by the heretofore known methods.

[Neuraminidase activity of nonpathogenic Neisseria]. / Neiraminidaznaia aktivnost' nepatogennykh neisserii.

It was revealed earlier by the authors that N. meningitidis of the principal serological groups A, B, and C possessed neuraminidase activity. In the present work it was shown that this sign was genus-specific, and that this property was also possessed by the representatives of nonpathogenic neisseria habituating in the nasopharynx, However, the enzymatic activity in nonpathogenic neisseria was less pronounced than in meningococci, and required more prolonged contact of the enzymatic-substrate mixture for its detection. There was revealed a direct relationship between the neuraminidase activity and the growth phase of the microorganisms, whose maximum coincided with the exponential phase of bacterial growth, this apparently being associated with the extracellular character of its origin.

[Neuraminidase activity of N. meningitidis]. / Neiraminidaznaia aktivnost' N. meningitidis

The work was aimed at the study of the neuraminidase activity of meningococci. The optimal conditions for detection of this enzyme in meningococci were chosen preliminarily. In experiments carried out with the observance of these conditions it was shown that meningococci of the main serological groups possessed neuraminidase activity revealed in the exponential growth phase of the microorganisms and was apparently of great pathogenetic significance providing a possibility of overcoming the physiological barrier of the host organism by the microbes.