[New nutrient medium for the cultivation and isolation of the plague microbe ChDS-37 as an element of the mobilization reserve of specialized antiepidemic teams of the Russian Inspectorate for the Protection of Consumer Rights and Human Welfare].

A new nutrient medium has been designed to culture and isolate the plague microbe ChDS-37 on the basis of the pancreatic digest of baker's yeast. The results of laboratory tests of the designed medium, by using 10 plague microbe strains and those of approval during the tactical and special training of a specialized antiepidemic team (SAET), suggest that the medium has some advantage over reference media and creates prerequisites for being incorporated into the mobilization reserve of a SAET.

[A monoclonal antibody-based study of the antigenic interrelations of typical and R forms of Vibrio cholerae]. / Izuchenie antigennykh vzaimosviazei tipichnykh i R-form kholernykh vibrionov na osnove monoklonal'nykh antitel.

Monoclonal antibodies to surface determinants of V. cholerae R forms (R-McA) were obtained. R-McA and monoclonal antibodies to lipopolysaccharide (LPS) of V. cholerae S forms (S-McA) were used to show that the LPS of deeply altered vibrios, agglutinating only with RO serum, completely lost its O-side chain. Some common O determinants on the basis of S-McA were detected in typical cultures of V. cholerae O1 and RO vibrios which agglutinated to 1/4 T with O serum and, in low titers, with RO serum. V. cholerae O1 were not capable of specifically binding with R-McA. Not all R strains under study were identified with the use of available R-McA due to essential differences of their terminal monosaccharides responsible for serological specificity.

[The reasons for the resistance of Vibrio cholerae to diagnostic phages]. / Prichiny ustoichivosti kholernykh vibrionov k diagnosticheskim fagam.

Phage resistance of 225 strains of cholera germs of O1 group obtained from different countries in 1988-1992 has been analyzed. Change of sensitivity to diagnostic phages was mostly connected with the decrease or loss of agglutinability in cholera sera. Phage resistance is rather conditioned by the change of the surface structures of the cell and by further change of phage reception zones. The increase in the number of strains sensitive to diagnostic phages after 6-12 months of storage evidenced for stabilization of cell wall structures and increase of their viability under relatively favourable conditions of storage.

[The agglutinability of cholera O-monoclonal immunoglobulins]. / K voprosu ob aggliutinabel'nosti kholernykh O-monoklonal'nykh immunoglobulinov.

A set of 10 monoclonal antibodies specific for vibrio species and of 5 monoclonal antibodies specific for serovar (Ogawa) was studied. These monoclonal antibodies were directed toward V. cholerae O1 antigen in agglutination reaction and on slide plates. Monoclonal antibodies agglutinating typical strains of cholera vibrios with titration range from 1: 6000 to 1: 25,000 were selected. MA were revealed to interact with cholera vibrio strains with reduced agglutinability. The set of agglutinating O monoclonal immunoglobulins was developed for laboratory identification of cholera O1 vibrios.

[Production of thermolabile enterotoxins of Escherichia coli by Yersinia enterocolitica and Yersinia pseudotuberculosis]. / Obrazovanie termolabil'nykh enterotoksinov kishechnoi palochki vozbuditeliami kishechnogo iersinioza i psevdotuberkuleza.

The plasmids pCG86 and RP4elt coding for thermolabile enterotoxins of Escherichia coli (LT) were transferred in conjugation to Yersinia enterocolitica and Yersinia pseudotuberculosis cells. Both plasmids were stably inherited by the recipient cells. The elt genes of the toxins were expressed in Yersinia cells at the level comparable to the one registered in Escherichia coli cells. In the broth cultures of transconjugant cells the major part of LT toxin is bound with cells (74-97%). The obtained data may serve an experimental basis in favour of possibility of Ent+ strains of Yersinia enterocolitica and Yersinia pseudotuberculosis formation in nature and expediency of search and diagnosing of such strains.