Evasin‐3‐like anti‐chemokine activity in salivary gland extracts of ixodid ticks during blood‐feeding: a new target for tick control

Ticks exploit many evasion mechanisms to circumvent the immune control of their hosts including subversion of the communication language between cells of the immune system provided by chemokines and other cytokines. One subversive molecule secreted in the saliva of Rhipicephalus sanguineus is Evasin‐3, a structurally unique 7 kDa protein that selectively binds the neutrophil chemoattractants, CXCL8 and (with lower affinity) CXCL1. We compared anti‐human CXCL8 and anti‐mouse CXCL1/KC activities in salivary gland extracts prepared from adult Amblyomma variegatum, Rhipicephalus appendiculatus and Dermacentor reticulatus ticks during blood‐feeding. Both anti‐CXCL8 activity and anti‐CXCL1 activity were detected in all species and in both adult females and males, with consistently higher activity levels against CXCL8. These results suggest that Evasin‐3‐like activity is common amongst metastriate ixodid tick species, and provide further evidence of the importance to ticks in controlling neutrophils during blood‐feeding. As such, Evasin‐3 offers a new target for anti‐tick vaccine development.     

Residing Staphylococcal virulence as a criterion for the ecological population load

In 1996-1999, a total of 8400 children living in 6 towns and 22 districts of the Orenburg Region were surveyed for resident Staphylococcus carriage. There was a relationship between the ambient air pollution, total morbidity due to respiratory diseases, and criterion Staphylococcus carriage. It has been found that resident Staphylococcus carriage determined by the persistent characteristics of strains may be used as universal test of microbiological monitoring in the ecological status of the atmosphere.     

Differences in antiopsonic effects of the extracellular products ofS. aureus andN. gonorrhoeae

Extracellular products ofS. aureus andN. gonorrhoeae decrease the efficacy of opsonization of these bacteria by blood serum. Antiopsonic activity ofS. aureus exometabolites is exhibited predominantly during their contact with serum components bound to bacterial surface, which disturbed the reactions between opsonines and neutrophils, as evidenced by decreased chemiluminescent signal during phagocytosis. With gonococci, this effect was observed predominantly during preliminary contact of their extracellular products with the serum, which attenuated the intensity of opsonization. Partial parallelism between changes in the neutrophil-stimulating activity of bacterial cultures and modification of their hydrophobic properties under the effect of the studied factors cannot be regarded as an absolute relationship. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 12, pp. 669–672, December, 1998     

Population characteristics of the factors of persistence ofEscherichia coli isolated from different ecological niches

The range of antilysozyme activity (the sign of persistence) ofEscherichia coli clones from subpopulations isolated from natural and artificial ecosystems is established. It is shown that heterogeneity of the microorganism population reflects the ecological status of its habitat. Therefore, it can be used as a test-indicator in biomonitoring and as an index in the standardization of eubiotics. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 356–358, September, 1996     

Mechanisms of persistence in bacterial pathogens

This paper gives an original classification of persistent bacterial mechanisms, that is based on the protection (isolation) of peptidoglycan, by recognizing the host immune system. The classification includes a bacterial cell wall screening and production of secreted agents, inactivating host defense, as well as antigenic mimicry, and bacterial wall-free formations (L forms). A group of novel bacterial secreted agents by suppressing host defense is described.     

Role of hypothalamic nonapeptides in interaction of prokaryotic and eukaryotic cells

The role of hypothalamic nonapeptides in the interaction of prokaryotic and eukaryotic cells was studied in the experimental setting. Nonapeptides were found to stimulate the adaptive and regenerative properties of eukaryotic cells and they are likely to have an antimicrobic effect on prokaryotic ones. The paper discusses the modulating role of nonapeptides in the establishment of symbiotic relations in the bacterial agent-host system.     

Microbiological criteria in the evaluation of drinking water quality

The obtained materials are indicative of a need to introduce new approaches towards both the process of drinking-water preparation and the evaluation of the drinking-water quality. It is necessary to take account of the symbiotic relations between the sanitary-significant bacteria, on the one hand, and algae and protozoa ensuring the survival of pathogens in the environment and worsening the water sanitary parameters, on the other hand, in working out the microbiological criteria applicable to the evaluation of the safety of drinking-water supply. Bacteria persistence can be reliable criteria in assessing the drinking-water quality. The use of qualitative characteristics (determination of persistent properties of microflora) alongside with the quantitative parameters should enhance the reliability of sanitary-and-microbiological assessments of the drinking-water quality.