The paper analyzes the change that occurred in the habitat of the causative agent of plague in its Gorno-Altaisk natural focus in 1961 to 2012. Since 1961 when the plague microbe was found to come from the southern slopes of the Saylyugem mountain range, which are located in Mongolia, to the northern slopes situated in Russia, a gradual expansion of the habitat of Yersenia pestis subsp. altaica had commenced in South-Eastern Altai. During the considered period, the area where epizootic manifestations were registered showed an 11-fold increase. In most cases, the spread of the plague pathogen within the focus was natural and occurred in the successive and closely related settlements of Mongolian pikas (Ochotona pallasi). By now, the plague microbe has been widely distributed in three populations of this small animal, which inhabit the territory of South-Eastern Altai.
Detection of DNA of Borrelia burgdorferi sensu lato was performed by PCR in taiga ticks Ixodes persulcatus, in blood samples and skin bioptates of small forest mammals, and in blood and urine samples of humans after attaching of ticks events. In Novosibirsk region both in natural reservoir and in patients with Ixodes ticks-borne borreliosis DNA of Borrelia garinii and Borrelia afzelii are detected. DNA of these borrelia were detected in 8 from 72 of taiga ticks, in 36 from 298 of blood and skin samples of small forest mammals, and in 32 from 102 of human blood and urine samples. In all studied samples DNA of B. garinii from NT29 subgroup was predominated. Borrelia DNA in which sequence of intergenic spacer region was homologous to sequence Chy13p first detected in China has been detected in one blood sample from red-backed vole (Clethrionomys rutilus).
89 primary isolates of B. garinii and 72 B. afzelii from different developmental phases of I. persulcatus, I. trianguliceps and form small mammalian hosts of Borrelia were obtained at an area of ca. 30 km2 located in low-mountain southern taiga forests (Perm region). The area provides home for two Borrelia species (B. garinii and B. afzeli) and their natural carrier Ixodes persulcatus. 23 isolate of B.garnii were obtained from skin biopsies and blood samples taken in patients with borreliosis. The isolates were studied by sequencing rrf(5S)-rrr(23S) spacer. The term genetic variant (genovariant) is proposed for the totality of isolates belonging to a given genetic subgroup of the concrete genospecies and having a similar nucleotide sequence of rrf(5S)-rrr(23S) spacer or other conservative genomic sequence. Genovariant is ths smallest intraspecies taxonomic unit in widespread Borrelia pathogenic for man. Several genovariants of B. garinii and B. afzelii may simultaneously occur in combined parasitic systems formed by these spirochetal agents of Ixodes tick-borne borreliosis. Such natural foci in southern taiga of the Perm region have a complicated etiological structure due to the presence of 14 genovariants of Borrelia belonging to the two above genetic subgroups. Specific genovariants occur annually but with different frequency. They are lacking in host-specificity.
Improvement of monitoring and prognosis of epidemic manifestations of natural foci of tularemia on the territory of Voronezh region using immune-serological and molecular-genetic study of main carriers of the disease.
539 small mammals captured during summer period of 2011 in 4 districts of North-Eastern part of Voronezh region were studied. Animal organs were studied by serologic (search for Francisella tularensis antigens) and molecular-biologic (detection of F. tularensis DNA) methods. Tularemia antigen was detected using passive hemagglutination reaction (PHAR) with erythrocytic tularemia immunoglobulin diagnosticum. Real-time polymerase chain reaction (RT-PCR) was applied for detection of tularemia causative agent DNA.
Complex study revealed epizootic activity of natural foci of tularemia in the examined territory. F. tularensis antigen and/or DNA were detected in 82 objects (15.2%). Use of RT-PCR allowed to additionally detect samples with relatively low content of F. tularensis DNA substrate, when antigen was not detected in samples. High sensitivity and specificity of the RT-PCR was ensured by inclusion of specific probes (tu14-PR2 and ISFTu2P).
The results obtained give evidence on functioning and epizootic activity of natural foci of tularemia in Voronezh region that requires constant monitoring of the territory and prophylaxis measures, first of all vaccination of risk groups by live tularemia vaccine.
Francisella tularensis subsp. tularensis is the common causal agent of tularemia in the USA and Canada, while F. tularensis subsp. palaearctica (holarctica) occurs in Europe, Asia, and to a minor extent in North America. F. tularensis subsp. mediaasiatica was found only in central Asia in a part of the former Soviet Union. Of the total of 155 F. tularensis strains isolated over the years 1978-1996 during the surveillance of tularemia in Slovakia, 65 were from small mammals, 68 from ticks and 22 from mites and fleas. They were characterized and classified by basic markers of infraspecific taxonomy in tests in vitro and compared with type strains of three subspecies and biovars of F. tularensis. Comparative studies have revealed biological properties characteristic of F. tularensis subsp. tularensis in 17 strains isolated from fleas and mites parasiting on small terrestrial mammals, collected in the Danube region, near Bratislava. These strains fermented glycerol, glucose, were positive for citrulline ureidase and sensitive to erythromycin, in contrast to the other 138 isolates classified as F. tularensis subsp. palaearctica (holarctica), biovar II, which fermented only glucose, were negative for citrulline ureidase and resistant to erythromycin. Two selected pairs of isolates with properties characteristic of F. tularensis subsp. palaearctica (holarctica), biovar II (SE-210, SE-234) and of F. tularensis subsp. tularensis (SE-219, SE-221), as shown in tests in vitro, were further examined for their pathogenicity on white mice, guinea pigs and domestic rabbits. In tests of virulence on domestic rabbits, the isolates SE-210 and SE-234 had low pathogenicity, while the isolates SE-219 and SE-221 exhibited high pathogenicity, which along with their biochemical properties confirmed their identification as strains of F. tularensis subsp. tularensis. The first findings of the highly virulent strains of F. tularensis subsp. tularensis in Europe indicate a serious event from epidemiologic and epiozootologic aspects, requiring systematic surveillance.
While the normal microbiota has been implicated as a critical defense against invading pathogens, the impact of enteropathogenic infection and host inflammation on intestinal microbial communities has not been elucidated. Using mouse models of Citrobacter rodentium, which closely mimics human diarrheal pathogens inducing host intestinal inflammation, and Campylobacter jejuni infection, as well as chemically and genetically induced models of intestinal inflammation, we demonstrate that host-mediated inflammation in response to an infecting agent, a chemical trigger, or genetic predisposition markedly alters the colonic microbial community. While eliminating a subset of indigenous microbiota, host-mediated inflammation supported the growth of either the resident or introduced aerobic bacteria, particularly of the Enterobacteriaceae family. Further, assault by an enteropathogen and host-mediated inflammation combined to significantly reduce the total numbers of resident colonic bacteria. These findings underscore the importance of intestinal microbial ecosystems in infectious colitis and noninfectious intestinal inflammatory conditions, such as inflammatory bowel disease.
Comment In: Cell Host Microbe. 2007 Aug 16;2(2):73-418005720
Based upon examination during the three-year-period 1972-74 of 2519 Danish game animals and of 415 warmblooded and 214 cold-blooded animals of foreign origin an attempt has been made to make out the incidence of Salmonella infection among Danish game as compared to Danish domestic animals, to estimate the risk of cross contamination in the kitchen from such animals, to find out if Danish game are infected from polluted areas, and to uncover the possible risk of introducing new Salmonella species with imported animals. The results (Table I) show a Salmonella incidence of 0.9% among Danish game, 1.3% among warm-blooded animals of foreign, and 13.6% among reptiles of foreign origin. Details about the distribution of types are given in Table II for animals of Danish origin, and in Table III for imported animals. The conclusion is: (I) In Denmark Salmonella infections are less common among game than among domestic animals. (II) Of game animals regularly used for human consumption only two mallards and no mammals yielded Salmonella, which implies that the risk of cross contamination is very small. (III) Except for sea-gulls Danish game do not seem to pick up infection from polluted areas. (IV) The greatest health hazard seems to be associated with imported reptiles, because these animals are potential excretors of Salmonella and because they are often sold as pets which means that especially children are exposed. Besides what is shown in the tables an outbreak of salmonellosis in small birds during the winter 1973-74 is described. This outbreak, however, does not influence the general estimate of the risk involved in the consumption of game, since small birds are not used for human food in Denmark.
The Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt, and Brenner, was discovered in blacklegged ticks, Ixodes scapularis Say at Turkey Point, Ontario, Canada. We report the first isolation of B. burgdorferi from a vertebrate animal collected on mainland Ontario. During this 2-yr study, spirochetes were isolated from the white-footed mouse, Peromyscus leucopus Rafinesque, and attached I. scapularis larvae. Similarly, isolates of B. burgdorferi were cultured from blacklegged tick adults, and confirmed positive with polymerase chain reaction by targeting OspA and rrf (5S) -rrl (23S) genes. Moreover, all isolates of B. burgdorferi from this area had complementary genetic structure, and the second primer set amplicons confirmed the first primer set amplification products. These findings show an epicenter endemic for B. burgdorferi within an established population of I. scapularis at Turkey Point.
Small mammals were trapped in northeastern Alberta, Canada during 1976. Blood samples from these animals were tested for virus by inoculation of suckling mice. Blood clots from two deer mice yielded isolates of the same virus. The virus was related antigenically to a number of flaviviruses which have been isolated from mammals in Central America and North America and was related most closely to Modoc virus. Physical, chemical, and biological properties of the virus were similar also to those of Modoc virus. It did not produce illness or death in deer mice inoculated in the laboratory. Neutralization tests indicated that 1/38 (3%) red squirrels (Tamiasciurus hudsonicus), 3/35 (9%) least chipmunks (Eutamius minimus), 13/109 (12%) deer mice, and 3/50 (6%) humans were infected naturally. This is the first reported evidence of infection of red squirrels and chipmunks with a Modoc-like virus. These data extend the range of Modoc-like viruses northward by 1,500 km and comprise the first isolate from mammals in the boreal forest of Canada.