The reactogenicity and immunological efficacy of a Klebsiella vaccine in donors

Klebsiella vaccine, when injected subcutaneously to donors, proved to be faintly reactogenic and safe. The injection of the vaccine had no effect on changes in the morphological composition of peripheral blood and on liver function. In persons with the initially low content of IgG an increase in this characteristic was observed after immunization. No changes in the synthesis of IgE occurred in healthy donors under the influence of immunization. The vaccine was shown to be immunogenic when introduced according to immunization schedules comprising 3 and 5 injections, the titer of Klebsiella antibodies increasing 3- to 5-fold.     

Various aspects of competitive relationship between Shigella and Escherichia coli]

One of the aspects of antagonistic relations could be the competence of microorganisms for specific sites of attachement to the epithelium common for shigellae and some E. coli serological types; this was demonstrated on a model of shigella-induced keratoconjunctivitis and in experiments with the HEp-2 cells infected with H3-glucose-labeled Sh. flexneri 5a, with combined administration of the latter with E. coli 08 and 028. The data obtained emphasized the importance for the development of the infectious process of the primary stage of shigella attachment to the epithelium. It was also revealed that the presence of common pili in the strains or production of colicine by bacteria intensified the antagonistic activity of E. coli, irrespective of their serological type.     

Use of a molecular diagnostic test in AFB smear positive tuberculosis suspects greatly reduces time to detection of multidrug resistant tuberculosis

Background

The WHO has recommended the implementation of rapid diagnostic tests to detect and help combat M/XDR tuberculosis (TB). There are limited data on the performance and impact of these tests in field settings.

Methods

The performance of the commercially available Genotype MTBDRplus molecular assay was compared to conventional methods including AFB smear, culture and drug susceptibility testing (DST) using both an absolute concentration method on Löwenstein-Jensen media and broth-based method using the MGIT 960 system. Sputum specimens were obtained from TB suspects in the country of Georgia who received care through the National TB Program.

Results

Among 500 AFB smear-positive sputum specimens, 458 (91.6%) had both a positive sputum culture for Mycobacterium tuberculosis and a valid MTBDRplus assay result. The MTBDRplus assay detected isoniazid (INH) resistance directly from the sputum specimen in 159 (89.8%) of 177 specimens and MDR-TB in 109 (95.6%) of 114 specimens compared to conventional methods. There was high agreement between the MTBDRplus assay and conventional DST results in detecting MDR-TB (kappa = 0.95, p<0.01). The most prevalent INH resistance mutation was S315T (78%) in the katG codon and the most common rifampicin resistance mutation was S531L (68%) in the rpoB codon. Among 13 specimens from TB suspects with negative sputum cultures, 7 had a positive MTBDRplus assay (3 with MDR-TB). The time to detection of MDR-TB was significantly less using the MTBDRplus assay (4.2 days) compared to the use of standard phenotypic tests (67.3 days with solid media and 21.6 days with broth-based media).

Conclusions

Compared to conventional methods, the MTBDRplus assay had high accuracy and significantly reduced time to detection of MDR-TB in an area with high MDR-TB prevalence. The use of rapid molecular diagnostic tests for TB and drug resistance should increase the proportion of patients promptly placed on appropriate therapy.     

Genetic Demography of the Population of St. Petersburg: Migration Processes

Russian Journal of Genetics - The principal genetic demographic parameters that describe migration processes affecting the structure of the St. Petersburg population gene pool were determined on...     

Effect of hydrophyte thickets density on zooplankton

An experimental study on the zooplankton community in the thickets of elodea Elodea canadensis Michx. of different densities (2, 4, and 8 g/L, wet weight/L) has been conducted. It is revealed that specific cationic composition and pH and sharp daily fluctuation of oxygen concentrations is a characteristic of the water in dense thickets of plants. Changes in water chemistry and in spatial organization of the environment influence zooplankton diversity and population dynamics of some species. With an increase in density of thickets, the number of Daphnia longispina O.F. Müller decreases, while the share of predators (Cyclopidae and Polyphemus pediculus O.F. Müller) increases. The abundance of Ceriodaphnia quadrangula (O.F. Müller) increases in the presence of plants, but does not depend on the density of the thickets. The correlation between the development of Simocephalus vetulus (O.F. Müller) and Diaphanosoma brachyurum (Liévin) and water cationic composition, changing in the process of growth and senescence of plants, is revealed.     

Influence of dendrite cells, generated with the use of immunomodulators of microbial origin, on the proliferative and cytotoxic activity of lymphocytes

The influence of ripe dendrite cells (DC) on the proliferative activity of mononuclear leukocytes and the cytotoxic activity of lymphocytes of syngenic mice was studied. As inducers of DC ripening, the combination of antigenic components incorporated into the vaccine "lmmunovac Bh-4", (Klebsiella pneumoniae, Proteus vulgaris, Escherichia coli, Staphylococcus aureus), as well as K. pneumoniae LPS and TNF-alpha, were used. This study demonstrated that DC activated with these preparations enhanced the proliferative activity of mononuclear leukocytes, the activity of Bh-4 being higher than that of K. pneumoniae LPS. The increase of proliferative activity was accompanied by a rise in the cytotovicity of mouse lymphocytes with respect to the NK-sensitive tumor line YAC-1 or Ehrlich tumor cells. The incubation of the lymphocytes with ripe DC (with the use of the preparations under study as ripening inducers), loaded with tumor antigens, made it possible to obtain cytotoxic lymphocytes having high cytotoxic activity with respect, mainly, to those tumor lines from which lysates for the treatment of DC had been produced. The activation of DC with bacterial immunomodulators led to an increase in the antigen-presenting function of these cells, to their higher capacity for regulating the differentiation of mononuclear leukocytes and for activating the cytotoxicity of natural killers.