[Dynamics of changes in antibiotic sensitivity of Vibrio cholerae 01, isolated from environmental objects]. / Dinamika izmenenii antibiotikochuvstvitel'nosti kholernykh vibrionov 01, vydelennykh iz ob"ektov okruzhaiushchei sredy.

The analysis of the dynamics of the antibiotic susceptibility of 442 strains of V. cholerae 01 isolated within 1986-1994 from the environment showed that the susceptibility level was different. Strains of V. cholerae 01 with high susceptibility to tetracyclines, erythromycin, gentamicin, rifampicin and cefazolin and with moderate susceptibility to monomycin, kanamycin, ampicillin, carbenicillin and levomycetin (chloramphenicol) were detected as well as the strains resistant to streptomycin and polymyxin B. The susceptibility of the V. cholerae 01 strains to certain antibiotics (tetracyclines, levomycetin, streptomycin) changed in regard to the isolation time and object and its geographical location. In 1991-1994 a tendency was observed towards an increase in the number of the strains resistant to the drugs. The resistance of the isolates from the objects connected with the vital activity of humans (sewage, washings from the cholera foci, fish from polluted water reservoirs) was higher than that of the isolates from open water reservoirs. There were definite difficulties in the detection of the cultures with antibiotic susceptibility characteristic of various regions because of their different origin. The results of the study were indicative of a necessity of monitoring of the biological properties of V. cholerae 01 isolates from the environment important for cholera control.

[The comparative characteristics of the antibiotic sensitivity of psychrophilic and mesophilic aeromonads]. / Sravnitel'naia kharakteristika antibiotikochuvstvitel'nosti psikhrofil'nykh i mezofil'nykh aéromonad.

The general regularities of the antibiotic susceptibility of psychrophilic and mesophilic aeromonads were determined. The antibioticograms were in general similar. Still, there was observed a higher susceptibility of Aeromonas salmonicida to tetracycline, chloramphenicol and rifampicin, as well as a larger number of strains susceptible to semisynthetic broad spectrum penicillins (ampicillin and carbenicillin) and cephazoline. The susceptibility to aminoglycosides was lower.

[The detection of antigenemia in typhoid patients at different periods in the course of the infection]. / Vyiavlenie antigenemii u bol'nykh briushnym tifom v raznye periody techeniia infektsii.

The enzyme immunoassay of serum samples, obtained from 37 typhoid patients and previously subjected to bacteriological study with negative results, permitted the detection of S. typhi specific antigens and, as a consequence, the rapid diagnosis of the disease. The prevalence of various antigenic components of S. typhi was observed at different stages of infection. The presence of surface O and Vi antigens was characteristic of acute stages of S. typhi infection. At the same time L-form antigens, in rare cases in combination with surface O and Vi antigens, were characteristic of patients at the period following the acute stage of the disease, as well as chronic carriers. This is indicative of the necessity of introducing specific antibodies to the antigenic determinants of S. typhi L forms into the assortment of diagnostic immune preparations.

[The antigenic characteristics of Salmonella typhi L forms]. / Izuchenie nekotorykh antigennykh osobennostei L-form Salmonella typhi.

The study of the possibility of detecting the specific antigens of S. typhi L forms has revealed that out of three destructive methods under study (osmotic lysis, freezing-thawing, sonication) only ultrasonic disintegration has proved to be effective for S. typhi L forms. Three specific fractions capable of interacting only with specific antibodies to S. typhi L forms have been revealed in the course of chromatographic separation of the soluble antigenic complex of S. typhi stable L forms and the subsequent analysis of the fractions thus obtained in the enzyme immunoassay.

[The possibilities of using variants of immunoenzyme analysis for detecting L-form Salmonella typhi bacteria in biological fluids]. / Izuchenie vozmozhnosti ispol'zovaniia razlichnykh variantov immunofermentnogo analiza dlia vyiavleniia L-form briushno-tifoznykh bakterii v biologicheskikh zhidkostiakh.

The possibility of using, on principle, the enzyme immunoassay (EIA) in different modifications for the detection of S. typhi L-forms in biological fluids (blood, urine) was established. The inhibiting variant of EIA showed the highest sensitivity: 1 ng/ml. The direct sandwich variant permitted the quantitative determination of the antigen of S. typhi L-form in the widest range of 20-500 ng/ml. The indirect enzyme immunometric variant permitted the detection of S. typhi L-forms with a sensitivity of 10(5) colony-forming units per ml only in urine.

[The process of the persistence of Salmonella typhi L forms in the body of experimental animals studied by immunoradiometric analysis]. / Izuchenie protsessa persistentsii L-form briushnotifoznykh bakterii v organizme éksperimental'nykh zhivotnykh metodom immunoradiometricheskogo analiza.

The use of the immunoradiometric assay made it possible to reveal a prolonged persistence of the antigen of viable cultures of S. typhi stable L-forms, as well as to study the dynamics of its spread in the body of experimental animals. After both subconjunctival and intraperitoneal infection of guinea pigs the antigen of S. typhi L-forms spread slowly in the body of experimental animals with its localization first in the lymphoid formations in the pharynx and the intestine and subsequent undulatory accumulation in the marrow, spleen and bile. The persistence of the antigen of live S. typhi L-forms lasted as long as 6 months (the term of observation); killed L-forms could be detected for not more than 17 days. Regular inoculations of samples from different organs into media for the cultivation of S. typhi bacterial and L-forms yielded no positive results, which showed the difficulty of obtaining stable L-forms and evidenced the absence of their reversion in the body of experimental animals.

[In vivo experimental modelling of the infectious process caused by stable L forms of the causative agent of typhoid]. / Modelirovanie v éksperimente in vivo infektsionnogo protsessa, obuslovlennogo stabil'nymi L-formami vozbuditelia briushnogo tifa.

To simulate the infectious process and to study the persistence of L-forms, rabbits and guinea pigs were infected with S. typhi stable L-forms. The materials presented in this work indicate that both subconjunctival and intraperitoneal infection led to the development of the clinically indistinct, but morphologically pronounced pathological process with characteristic localization and typical changes in the gastrointestinal tract. The typical features of the process were the generalized immunomorphological reaction of the lymphoid apparatus with the appearance of light-colored reticulomacrophagal elements, the signs of the activation of humoral and cell-mediated immunity and the formation of small epitheloidocellular granulomas. The results of the investigation indicate that the stable cultures of S. typhi L-forms are highly pathogenic and capable of inducing the infectious process in experimental animals.

[Antigenic structure of Salmonella L forms studied by an immunoferritin method]. / Izuchenie antigennoi struktury L-form sal'monell s pomoshch'iu immunoferritinovogo metoda.

The antigenic structure of the L-forms of salmonellae (S. typhimurium and S. typhi) in comparison with that of the initial bacterial cultures and revertant cultures was studied with the use of the immunoferritin method. The L-forms of salmonellae were found to retain an insignificant amount of O-antigen, as well as to have K-antigen on the surface of the cytoplasmic membrane, but in a lesser amount than the initial strains. In the cultures reverting from the L-forms of S. typhimurium and S. typhi the quantitative and qualitative characteristics of O- and K-antigens were completely restored.

[Immunoelectrophoretic analysis of the antigenic composition of Salmonella typhi in the process of L transformation and reversion]. / Immunoélektroforeticheskii analiz antigennogo sostava Salmonella typhi v protsesse L-transformatsii i reversii.

In the study of the antigenic composition of S. typhi L-forms and their revertants were determined. The stable L-forms were characterized by profound disturbances in the synthesis of Vi- and H-antigens. After reversion to bacterial forms all the revertants under study showed the complete restoration of their bacterial antigenic structure.

[Formation and persistence of L-variants of Salmonella typhi in experimental typhoid and in carriers]. / Obrazovanie i persistentsiia L-variantov Salmonella typhi v techenie éksperimental'noi briushnotifoznoi infektsii i bakterionositel'stva.

The possibility of the induction and persistence of S. typhi L-forms in the process of experimental typhoid infection and carriership has been studied in rabbits. This study has revealed that the process of L-transformation leading to the appearance of the imbalanced growth forms and unstable L-forms of S. typhi in the organism of the animals infected with S. typhi culture may occur under the conditions of carriership. Such changed forms can be detected in the organism of the animals 18 months after the primary infection.

[Dynamics of the changes in the level of antibiotic sensitivity of staphylococci isolated in 1959-1977]. / Dinamika izmenenii urovnia chuvstvitel'nosti k antibiotikam stafilokokkov, vydelennykh v 1959-1977 gg.

The study of antibiotic sensitivity in staphylococci isolated from the patients in the clinic of the N. N. Burdenko Research Institute of Neurosurgery of the USSR Academy of Medical Sciences in 1977 showed that in this stationary in 1977 predominated cultures resistant to benzylpenicillin. The number of the isolates resistant to streptomycin, levomycetin and erythromycin was high. The percentage of the strains resistant to tetracycline was the least. Still up to 1973 the resistance level to tetracycline among staphylococci was high. Possibly such a dynamics of the changes in the staphylococcal sensitivity to tetracycline was relative and mainly defined by the changes in the system of the results estimation using the paper disc procedure.