Isolation of Tahyna virus from biting midges (Diptera, Ceratopogonidae) in Czecho-Slovakia.

A total of 14,250 haematophagous biting midges (genus Culicoides, Diptera: Ceratopogonidae) were collected in June 1986 in the mountains Ceskomoravská vysocina (about 600 m above sea level); from these 2 strains of Tahyna virus (serogroup California, Bunyaviridae) were isolated. To our knowledge this is the first isolation of a California serogroup virus from the species of family Ceratopogonidae as well as the first report of arbovirus isolation from biting midges in Europe.

A comparison of the occurrence of borreliae in nymphal and adult Ixodes ricinus ticks.

The prevalence of borreliae in 209 nymphal and 251 adult Ixodes ricinus was investigated in two areas of southern Moravia, Czechoslovakia, using the dark-field and the Giemsa stained-smear techniques. The proportions of infected ticks were 3.8% in nymphs and 10.

Persistence of Clostridium botulinum type C toxin in blow fly (Calliphoridae) larvae as a possible cause of avian botulism in spring.

Diverse samples were examined at a site of water-bird mortality, caused by Clostridium botulinum type C toxin in southern Moravia (Czechoslovakia). The toxin was detected in high concentrations in mute swan (Cygnus olor) carcasses (less than or equal to 1 x 10(6) LD50/g) as well as in necrophagous larvae and pupae of the blow flies Lucilia sericata and Calliphora vomitoria (less than or equal to 1 x 10(5) LD50/g) collected from them. It was detected in lower concentrations (less than or equal to 1 x 10(3) LD50/g) in other invertebrates (ptychopterid fly larvae, leeches, sow-bugs) associated with these carcasses, and occasionally in water samples (8 LD50/ml) close to the carrion.

Isolation and characterization of Sedlec virus, a new bunyavirus from birds.

A pathogenic agent designated AV 172 was isolated from the blood of a Reed Warbler (Acrocephalus scirpaceus) out of 767 samples from birds belonging to 35 species and 14 families. The birds (largely wetland passerines) were captured in the reed-belt littoral of Nesyt fishpond in southern Moravia, Czechoslovakia, during the years 1984 to 1987. Virus AV 172 has been found to represent probably a new species (designated virus "Sedlec") of family Bunyaviridae.

A new genus of capillariids from birds, Tridentocapillaria gen. n. (Nematoda: Capillariidae).

A new genus of the family Capillariidae, Tridentocapillaria gen. n., has been established.

Francisella tularensis from ixodid ticks in Czechoslovakia.

A total of 26,478 ixodid ticks (935 pools) were examined by intracerebral inoculation of suckling mice. Six species of ticks were tested: Ixodes ricinus (23,470 individuals), I. trianguliceps (12), Haemaphysalis punctata (831), H.

A new genus of capillariids from birds, Ornithocapillaria gen. n. (Nematoda: Capillariidae).

A new genus, Ornithocapillaria gen. n., belonging to the family Capillariidae and subfamily Baruscapillariinae is described and its diagnosis is given.

Prevalence of borreliae in Ixodes ricinus ticks from southern Moravia, Czechoslovakia.

A total of 378 adult Ixodes ricinus ticks were collected by flagging vegetation in four localities of two districts (Breclav, Znojmo) in south Moravia and examined microscopically. Borreliae were identified in Giemsa-stained midgut smears from 32 (i.e.

Results of arbovirological examination of birds of the family Hirundinidae in Czechoslovakia.

Migratory birds (swallow, Hirundo rustica; sand martin, Riparia riparia; house martin, Delichon urbica) caught in southern Moravia (Czechoslovakia) in 1984-87 were examined for arbovirus infections. Isolation experiments were carried out using blood samples of 183 birds (52 swallows, 107 sand martins, and 24 house martins). The results were negative.

Thermal sensitivity of Clostridium botulinum type C toxin.

A sterile suspension containing 950 mouse LD50 per ml of type C botulinum toxin was exposed for various periods to different temperatures. The time required for the 99% (hundred-fold) reduction of toxicity was more than 5 years at -70 degrees C or -20 degrees C, 6 months at +5 degrees C, 3 weeks at +20 degrees C, 2 weeks at +28 degrees C, 2 days at +37 degrees C, 9 h at +42 degrees C, less than 30 min at +56 degrees C, less than 20 min at +60 degrees C, and below 5 min at +80 degrees C. The results suggest that Clostridium botulinum type C toxin, if produced in an ecosystem of the mild climatic zone, might persist there over the winter season and cause the intoxication of vertebrates next early spring in the absence of further microbial toxigenesis.

Isolation of "exotic" Bhanja virus (Bunyaviridae) from ticks in the temperate zone.

One strain of Bhanja virus was isolated from Dermacentor marginatus male ticks collected from sheep in Slovak Karst, eastern Czechoslovakia (48 degrees 31'N, 20 degrees 28'E). In addition, three strains of Brezová virus (subtype of Tribec orbivirus, Reoviridae) were isolated from Ixodes ricinus ticks. The result represents the northernmost isolation of Bhanja virus and, moreover, its first recovery from D.