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A total of 150 nymphal Ixodes ricinus (L., 1758) (Acari: Ixodidae) from the Czech Republic were examined for Anaplasma phagocytophilum (Foggie, 1949) Dumler et al., 2001 by PCR using EHR521/747 primers: 22 of 50 pools were positive (minimum prevalence, 14.7%). However, sequencing of the PCR products did not show complete homology with A. phagocytophilum (91%) while the closest relationship (95%) was found to "Candidatus Ehrlichia walkefii". The results indicate a need for care in interpretation of Anaplasma PCR results and for PCR optimization for detecting A. phagocytophilum in ticks.

Lyme borreliosis (LB) is a serious infectious disease of humans and some domestic animals in temperate regions of the Northern Hemisphere. It is caused by certain spirochetes in the Borrelia burgdorferi sensu lato (s.l.) species complex. The complex consists of 11 species (genospecies). Borrelia burgdorferi sensu stricto (s.s.), Borrelia garinii and Borrelia afzelii are the major agents of human disease. Borrelia burgdorferi s.l. species are transmitted mainly by ticks belonging to the Ixodes ricinus species complex plus a few additional species not currently assigned to the complex. B. burgdorferi infections may produce an acute or chronic disease with a wide array of clinical symptoms such as erythema migrans (EM), carditis, arthritis, neuroborreliosis, and acrodermatitis chronica atrophicans (ACA). Differences in LB spirochetes 'genospecies' and strains/isolates determine the occurrence and severity of this multi-system disease. Accurate and reliable identification of the LB spirochetes in ticks as well as knowledge of their prevalence are essential for prevention against the disease and development of an effective vaccine. An overview of the knowledge of molecular factors with emphasis on potential protein-carbohydrate interactions in the tick-borrelia system is the main focus of this review.

A total of 350 nymphs of the common tick Ixodes ricinus (Linnaeus, 1758) were collected in an endemic focus of Lyme borreliosis (South Moravia, Czech Republic) and examined for the presence of the protozoan Babesia microti (França, 1909) by polymerase chain reaction (PCR), using primers specific for the B. microti gene encoding small subunit rRNA. The assay revealed five positive pools (out of 70 pools examined); the corresponding prevalence rate was about 1.5%. Sequence analysis of the PCR products confirmed their 100% homology with that of B. microti. The study represents the first evidence of B. microti in ixodid ticks in the Czech Republic.

Using degenerative primers designed on the basis of known sequences of lectin genes from different sources a fragment of genomic DNA of Borrelia burgdorferi (strain B31) that contained a lectin-like sequence was isolated, cloned and sequenced. The presence of an open reading frame of 268 amino acids (position 1501-2304 bp) and the computer analysis of the predicted amino acid sequence showed 37% of identity and 75% of homology over region of 25 amino acids with the legume lectin proteins, including erythroagglutinating phytohemagglutinin (PHA-E) and leucoagglutinating phytohemagglutinin (PHA-L). The further analysis of the predicted amino acid sequence showed the presence of another two domains (positions 198-211 and 215-226 aa) consisting of the characteristic conserved sequence motifs for legume lectin proteins. Hemagglutinating activity was detected in lysate of B. burgdorferi (strain B31) spirochete and the affinity to fetuin was determined in a hemagglutination inhibition test. Hemagglutinating activity was also found in a crude lysate of the recombinant clones carrying the fragment of B. burgdorferi genomic DNA. The inhibition of agglutinating activity by fetuin, D-galactosamine and D-mannosamine was determined using the standard procedure of hemagglutination inhibition test with native rabbit red blood cells (RBC).

Lectins and their glycosylated receptors in a system of the tick-transmitted pathogen are the addressed topics which the minireview is dealing with. They participate in the reciprocal protein-saccharide interactions in the transmission of the causative agents of the tick-borne encephalitis and Lyme borreliosis by the ticks. Functional significance of the tick tissue specific lectins as well the lectins/aggulutinis of the transmitted pathogens in molecular ecology of the tick borne diseases has been shown.

Two distinct hemocyte populations are determined in the hemolymph of the triatomine bug Triatoma infestans Klug, oenocytoids and plasmatocytes, and their independent origin from separate stem cells is shown. Both hemocyte populations differ considerably in their morphology, ultrastructure and lectin-binding properties. While oenocytoids are quite uniform with easily definable cells which do not to bind any assayed lectin, the plasmatocytes are a very polymorphic population possessing several morphological types and displaying a positive reactivity with lectins.

Haemagglutination activity (HA) was found and characterized in a midgut homogenate of Ixodes ricinus (L.). HA was induced by tick feeding; it was not detected in starved ticks. In a haemagglutination inhibition test, HA showed an affinity for some carbohydrates (N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, rhamnose, and dulcit) and glycoconjugates (especially lipopolysaccharides). Midgut protein components of 37, 60, 65, and 73 kDa were identified by immunoblotting as potential structural subunits of the new agglutinin.

Lectin activities were studied in five different species of tsetse flies. Different native or enzymatically treated human or animal red blood cells were used to detect hemagglutination activity in midgut extracts. Two inducible lectin systems in the midgut of G. tachinoides were distinguished.

Number and relative molecular weights of proteins in whole body homogenates of the louse, Polyplax spinulosa were determined using SDS-PAGE. 13 protein components from the total of 28 bands were defined as Con A binding glycoproteins. In immunoblotting sera of lice infested laboratory rats of BN strain specifically recognized 3 major protein components with r.m.w. of 77,000, 105,000 and 230,000 Da and from 6 to 8 minor protein components with r.m.w. of 31,000-180,000 Da.

A system of IgM-capture EIA made up from Czechoslovak immunopreparations (SEVAC) was developed for a rapid serological diagnosis of tick-borne encephalitis (TBE). The method was tested on clinical material. The total IgM antibody titres were detected using pig antiserum and the selection of specific IgM antibodies was made with TBE antigen with following indirect way of detection. The antibody analysis made by means of this method is sensitive and fully conforms to the clinical picture of the disease.

Circulating antibodies to larval Argas polonicus antigen detected in the blood of pigeons by means of ELISA reach their highest level 3-6 days post-tick attachment. During 6-8 days post infestation when most larvae detach from their host, there is an abrupt drop of the antibody level in blood followed by second peak at day 10-15. During the secondary and subsequent infestations the dynamics of the antibody production is analogous, but the maximum absorbance values found are higher with each following infestation. This is in direct correlation with the growth of immune resistance of hosts. The transfer of immunoglobulins of resistant pigeons produces in naive hosts a partial resistance in a statistically significant (P less than 0.01) reduction of the number of engorged larvae, in the shortening of larval feeding period and in the decrease of their mean weight after feeding. However this resistance was significantly (P less than 0.01) less expressed than in naturally resistant pigeons during secondary infestation. The protracted effect on the duration of premoulting period and the percentage of moulted larvae manifested in larvae after secondary infestation was not apparent in molecular weight of approximately 19, 21, 23, 27, 45 and 165 kilodaltons, were recognized by serum of resistant pigeons.

Tick-borne encephalitis (TBE) virus was isolated from a sample of Ixodes hexagonus ticks collected from the hair of the western European hedgehog (Erinaceus europaeus) which had been captured on the edge of a new housing estate in Ceské Budĕjovice at the end of September 1986. This was the first isolation of TBE virus from this vector, supporting the previous experimental results. The virus was identified in immunofluorescent and plaquereduction neutralization tests.