Characteristics of Pseudomonas aeruginosa pili and an elucidation of their relation to the virulence of the bacteria

The electron microscopic study of 175 P. aeruginosa museum and newly isolated strains has been made and their virulence has been determined. In 32% of these strains the presence of pili has been established. However, among the museum strains those with pili have been found to constitute only 19.5%, while among newly isolated strains pili have been detected in 39.7% of cases (the difference is statistically significant at p less than 0.01). No correlation between the formation of pili and the virulence of P. aeruginosa has been established.     

The antigenic characteristics of the capsid proteins in strains of the potato virus Y]

The antigenic properties of capsid proteins of potato virus Y (PVY) strains have been studied, the most wide antigenic specificity of necrotic group strains has been marked. Several antigen-active strains of necrotic group strains (PVY-N Far East, PVY-N Leningrad, PVY-N Moscow) and common group (PVY-O-3 Moscow, PVY-O Far East) have been revealed. Antisera against these strains reacted with any PVY strain. Virus specific surface epitope, corresponding to position 198-208 of polypeptide chain has been located, which is a group-specific epitope of potyviruses, identified in the Far East.     

Inhibition by glycine of the growth of methylotrophic bacteria : Some resistant mutants

Summary The action of glycine as an inhibitor to different species of methylotrophic bacteria possesing the serine pathway has been shown. With all the strains, glycine-resistant mutants have been obtained. A comparative study of growth parameters for both the mutant and wild strains has, been made. Better gram negative strains have been isolated but the same cannot be said for the gram positive strains.     

Limitation of phage multiplication by microbes of the genus Bordetella

Possible causes limiting the multiplication of Bordetella phages or inducing their restriction, such as the influence of lysogenic immunity and the restriction-modification (R-M) system or the incompatibility of the receptor apparatus, have been studied. The limitation of the multiplication of phages by some B. bronchiseptica and B. pertussis strains has been shown to be due to the presence of the R-M system and lysogenic immunity. In five B. bronchiseptica strains and two B. pertussis strains site-specific endonucleases (restrictases) with Hind III specificity have been detected. One B. bronchiseptica strain without the R-M system has been detected. B. bronchiseptica strains producing site-specific endonucleases are practically nonpathogenic for humans, grow in common culture media and selectively produce only one restrictase, type Hind III, which guarantees from the admixture of other specific endonucleases. The B. parapertussis strains under study (altogether 100 strains) have not been found to limit the multiplication of Bordetella test phages. The absence of site-specific endonucleases has also been confirmed biochemically. These strains are recommended as indicator strains for the multiplication of Bordetella phages.     

Characteristics and utilities of luminescent bacteria from the Black sea

Luminescent bacteria, isolated from summer specimens of water of the Black sea, have been identified as strains of Photobacterium phosphoreum and Vibrio fischeri (two of each). Morphological, physiological, and biochemical properties of the four strains have been characterized, and the kinetic behavior of luciferases isolated therefrom has been studied. The sensitivity of the luminescence of the strains to certain toxic agents has been compared to that of the test strain Ph. phosphoreum (Cohn) Ford. The results obtained indicate that the new strains show promise as bioindicators.     

Structural dynamics of strains of a hepatitis B virus population in the Ukraine and its etiological prognosis

Changes in the population structure of influenza B virus in the Ukraine since 1980 has been studied. New strains of the virus have been identified and the epidemic potentials of different strains have been compared. The data on the drift mechanism of the origin of the intermediate strains of influenza B virus have been observed. A suggestion on the etiological prognostication of the epidemic process has been made.     

Radioimmunological analysis of the antigenic variability of influenza virus nucleoprotein

Influenza A virus ability to bind anti-NP monoclonal antibodies to two viral strains has been studied by radioimmunoassay on polyethylene film with the subsequent autoradiographic registration of results. Monoclonal antibodies were obtained to the viral strains differing in antigenic formula of outer glycoproteids and isolated at different time. The studied influenza viruses were divided into seven groups due to their ability to bind monoclonal antibodies. The absence of correlation between the antigenic properties of nucleoprotein and glycoproteids has been registered. Variability of some antigenic sites has been analyzed. The human epidemic strains of influenza virus are different in ability to bind monoclonal antibodies from the viral strains that are connected with animals in nature or laboratory practice.     

Utilities of Luminous Bacteria from the Black Sea

Luminous bacteria, isolated from summer specimens of water of the Black Sea, have been identified as strains of Photobacterium phosphoreum and Vibrio fischeri (two of each). Morphological, physiological, and biochemical properties of the four strains have been characterized, and the kinetic behavior of luciferases isolated therefrom has been studied. The sensitivity of the luminescence of the strains to certain toxic agents has been compared to that of the test strain Ph. phosphoreum (Cohn) Ford. The results obtained indicate that the new strains show promise as bioindicators.     

Production and experimental testing of the polyvalency of corpuscular vaccine for the prevention of Pseudomonas aeruginosa infections II. Experimental testing of the immunogenicity of polyvalent corpuscular Pseudomonas aeruginosa vaccine

Newly developed P. aeruginosa vaccine has been shown to be safe and apyrogenic for experimental animals. Immunization with the vaccine in a single injection of 0.5 ml has been found to ensure the protection of 80--98% of mice from lethal infection caused by virulent vaccine strains, with the exception of P. aeruginosa strain No. 1311, for 9 weeks. Immunity to P. aeruginosa strain No. 1311 develops only by day 56 after vaccination. No sharp correlation between the specific agglutinin level and the degree of protective effect induced by the immunization of animals with the polyvalent vaccine has been established. The vaccine has been shown to possess high immunogenicity in respect to clinical P. aeruginosa strains belonging to different serotypes (homo- and heterological vaccine strains).     

The use of a molecular hybridization method for studying the enterotoxigenic properties of Salmonella

The occurrence of the tox gene among 320 Salmonella strains of 23 serovars, differing in their origin, sensitivity to antibiotics, the presence of R-plasmids and a number of biochemical properties, has been studied by the method of DNA-DNA hybridization in situ. Essential differences in the occurrence of the tox gene have been detected both among S. typhimurium hospital strains and strains isolated in sporadic diseases, from the environment, from animals and among salmonellae belonging to different serovars. The direct correlation between the presence of the enterotoxigenicity gene and plasmids controlling resistance to antibiotics in Salmonella strains has been established. The expediency of using the method of gene probing for the study of the enterotoxigenic properties of salmonellae has been substantiated.     

Use of the DNA-DNA hybridization method on filters for determining the toxic potency of atypical strains of Vibrio cholerae isolated from natural sources

The methods of the radioimmunoassay and the blot hybridization of restricted fragments of chromosomal DNA have been used for the characterization of V. cholerae atypical strains isolated from the natural environment. For all strains under study, the radioimmunoassay has been found to yield the most sharply defined data characterizing their atoxigenicity. The absence of the structural genes of toxin in the chromosomes of these strains has been shown by the method of blot hybridization. Some methodological simplifications of blot hybridization, having no adverse effect on the sensitivity of this method, have been tested.     

Study of a lipopolysaccharide from Yersinia pseudotuberculosis of the IVA serotype

The comparative studied on lipopolysaccharides from Yersinia pseudotuberculosis IVA serovar, strains 32 and 31D, have been conducted. The identity of the lipopolysaccharides isolated from these strains has been shown. The structural pattern of the repeating unit of the O-specific side chain of the lipopolysaccharide has been suggested: (Formula: see text)     

Culture properties of the causative agent of tularemia isolated in natural foci in Stavropol Territory, the Kalmyk ASSR and the Armenian SSR

The strains isolated in natural foci of the Stavropol Territory and the Armenian SSR have been found to belong to the holarctic race of Francisella tularensis, biovar II. In natural foci of the Kalmyk ASSR the strains belonging to biovars I and II have been isolated. The study of the tularecinogenicity of the cultures has revealed the existence of strains which are not sensitive to their own tularecins. The phenomenon of tularecinogenicity in F. novocida has been established. Avirulent strain 319/38 belonging to the non-arctic race is recommended as an indicator strain for the determination of tularecinogenicity.     

Evolutionary perspective on the origin of Haitian cholera outbreak strain

Cholera epidemic has not been reported in Haiti for at least 100 years, although cholera has been present in Latin America since 1991. Surprisingly, the recent cholera epidemic in Haiti (October 2010) recorded more than 250,000 cases and 4000 deaths in the first 6 months and became one of the most explosive and deadly cholera outbreak in recent history. In the present study, we conducted genomic analyses of pathogenicity islands of three Haitian Vibrio cholerae strains and compared them with nine different V. cholerae O1 El Tor genomes. Although CIRS101 is evolutionarily most similar to the Haitian strains, our study also provides some important differences in the genetic organization of pathogenicity islands of Haitian strains with CIRS101. Evolutionary analysis suggests that unusual functional constraints have been imposed on the Haitian strains and we hypothesize that amino acid substitution is more deleterious in Haitian strains than in nonHaitian strains.     

Isolation of monoclonal antibodies for the identification of strains of the causative agent of plague that do not contain a capsular antigen

In most cases the immunological identification of Y. pestis strains is based on the use of capsular antigen as an immunological marker. However, there are Y. pestis strains without capsular antigen. For the immunological identification of such strains, homogeneous antigen with a molecular weight of 43 KD has been isolated and monoclonal antibodies to it have been obtained. The enzyme-linked immunosorbent assay, carried out with the use of these monoclonal antibodies and intended for the detection of antigen with a molecular weight of 43 KD, has been developed. The sensitivity of the assay is about 10 ng/ml.     

The genomic fingerprinting of the causative agents of sapronoses

The genome polymorphism of the causative agents of sapronoses (Vibrio cholerae, Legionella and Leptospira) has been studied. The use of the method of genome fingerprinting [correction of dactyloscopy] has been shown to permit the differentiation of closely related strains of such causative agents. The epidemically significant strains of the causative agents of sapronoses, isolated in different geographical regions, have been found to be genotypically related, i.e., they are probably of clonal origin. Avirulent and nontoxigenic strains are genotypically heterogeneous and differ both from one another and from epidemically significant strains. Using V. cholerae as an example, the hypothesis of the appearance of potentially dangerous variants at the epidemic period in the absence of their release at the period between epidemics is considered.     

Cytochrome Composition of Some Members of the Actinoplanaceae

The cytochrome composition of 19 strains of Actinoplanaceae has been investigated. The principal cytochrome found was cytochrome b, and occasional strains showed the presence of cytochrome a.     

Updating the H-antigen classification of Bacillus thuringiensis

The classification of Bacillus thuringiensis strains has been revised and updated based on flagellar antigens which have been in use for many years. Sixty-nine serotypes and 13 sub-antigenic groups have now been identified, giving 82 serovars among the 3500 B. thuringiensis isolates of the IEBC Collection. The number of serovars has gradually increased with the total number of strains. The biochemical characters used have also been investigated and their value assessed for identification of B. thuringiensis at the subspecies level. A crystal analysis was carried out in terms of morphology, delta-endotoxin profiles and larvicidal activity for the newly identified serovars. It was found that atypical crystals, some with novel components, are becoming more common. No insect susceptible to these serovars has been discovered among known target species. The number of cross-reacting H-antigens among B. cereus strains is increasing and may be of biological significance.     

The use of molecular biological methods for the individual characterization of Mycobacterium tuberculosis strains

The expediency of using molecular biological methods for the evaluation of M. tuberculosis clinical strains by individual genetic certification of circulating M. tuberculosis strains has been substantiated. Considerable genetic heterogeneity of M. tuberculosis strains isolated from patients in different regions of the Russian Federation has been established; this heterogeneity is due to the presence of differences in the number of copies (5-26) of element IS6110 in M. tuberculosis cells.     

Orientation of the guanine operon of Escherichia coli K-12 by utilizing strains containing guaB-xse and guaB-upp deletions.

Temperature induction of an Escherichia coli strains with lambda cI1857 integrated in the guaB gene has been used to produce strains containing chromosomal deletions extending into the xse and upp genes. By utilizing strains containing these deletions, it has been possible to order the genes in the guanine operon with respect to the xseA and upp genes. The order of the genes in this region is glyA-hisS-xseA-guaO-guaB-guaA-purG-upp-purC.