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1.
Morii T., Matsui T., Iijima T. and Fiotnaoa F. 1984. Infectivity of Leucocytozoon caulleryi sporozoites developed in vitro and in vivo. International Journal for Parasitology14: 135–139. Infectivity of Leucocytozoon caulleryi sporozoites isolated from various sites in Culicoides arakawae and from the midguts and the salivary glands which had been cultured in vitro after the infective blood meals was studied. Sporozoites isolated from the midguts, the abdominal and thoracic hemocoel and the salivary glands of biting midges on the 2nd day after feeding did not show infectivity to any of the chickens inoculated. Sporozoites obtained from the salivary glands on the 3rd day after feeding caused infection in all the inoculated chickens. The results indicated that sporozoites which had been just released from oocysts or had just reached the salivary glands cannot induce infection in chickens. Sporozoites were produced in the midguts which had been cultured in vitro in Medium 199 or Grace's medium after the infective blood meals, but they showed lower infectivity than those isolated from the salivary glands which had been cultured by the same methods as the midgut cultivation. The development of infectivity of L. caulleryi sporozoites seems to be site-dependent rather than time-dependent. High infectivity of sporozoites develops during their residence in the salivary glands of biting midges.  相似文献   

2.
Bacterial specific primers were used to amplify 23S rRNA genes from a representative strain from each of the 23 serogroups of the pathogenic Leptospira interrogans and 8 strains from 6 serogroups of the non-pathogenic Leptospira biflexa. Only regions of extreme variability, which had been identified on the basis of homology-based search of all the 23S rRNA sequences available in GenBank database, were sequenced from the amplified products. PCR primers that had the potential to distinguish L. interrogans from L. biflexa species were designed from the derived sequences and a sensitive PCR protocol developed. The PCR method enabled the differentiation of the 59 strains of the 23 serogroups of L. interrogans from the 8 strains of 6 serogroups of L. biflexa. Further investigation by 16S rDNA sequencing of two strains of L. interrogans, which gave unexpected PCR results, provided evidence that they had been misclassified and hence we propose to reassign them to L. biflexa.  相似文献   

3.
Seventeen monoindole alkaloids have been isolated and identified from Hazunta modesta var. modesta subvar. montana. Five of them had not previously been isolated from a Hazunta species. Two of these five are apparently new compounds.  相似文献   

4.
From the whole plant of Ajuga pseudoiva two epimeric neo-clerodane diterpenoids, 2-acetylivain I and its C-2 epimer 14,15-dihydro-ajugapitin, have been isolated. The structures were established by spectroscopic and chemical means. 2-Acetylivain I had not been previously reported, while its C-2 epimer had been isolated from Ajuga chamaepitys.  相似文献   

5.
Abstract:In contrast to virtually all other species of ruminants, reindeer (Rangifer tarandus) eat substantial amounts of lichens in winter. Several different species of lichens are eaten and most are highly palatable. The chemical composition and the in vitro digestibility of six species of terricolous lichens commonly eaten by reindeer were measured. Ruminal inoculum was obtained in winter from six free-ranging reindeer that had been grazing on natural pastures in northern Norway. Analysis of the plant parts recovered from their rumens confirmed that the animals had been eating a mixed diet that included both lichens and vascular plants. The chemical composition and the in vitro digestibility of the different species of lichens varied considerably between species and genera. Cetraria islandica, C. nivalis andCladonia arbuscula were highly digestible [69–77% dry matter (DM)], Stereocaulon paschale was poorly digestible (43% DM), whereas Cladonia stellaris and C. gracilis had an intermediate digestibility (56–57% DM). Mixing Cladonia stellaris with vascular plants (50:50) had no effect on the in vitro digestibility of the combined substrates. The in vitro digestibility of Cladonia stellaris in inoculum from two captive reindeer which had had no access to lichens was very low (10% DM). This shows that the source of inoculum used for digestibility trials has a major effect on the apparent digestibility of the substrates. Evidently, the extent to which reindeer are able to utilize lichens depends on the species that are selected and on what the animals have been eating recently.  相似文献   

6.
An assay to measure the specific proliferation in vitro of peripheral blood leukocytes (PBL) in response to ultrasonicated trypanosomes was adapted for use in cattle. The kinetics of mitosis exhibited by PBL from cattle which had been treated following infection with Trypanosoma congolense paralleled the development of a delayed-type skin reaction elicited with ultrasonicated and Formalin-fixed T. congolense. Responses in both tests were maximal on the fourth day after initiation. Specific proliferation of PBL harvested from cattle which had been immunized with intact, nonviable trypanosomes was also elicited in vitro by trypanosomal antigen. Peripheral blood leukocytes taken from cattle immunized with 50 μg of variant-specific surface antigen (VSSA) from T. brucei and from cattle infected with T. congolense were not stimulated to divide in vitro by ultrasonicated trypanosomes.  相似文献   

7.
Twenty four monoindolic alkaloids have been isolated and identified from aerial parts of Catharanthus ovalis. Twelve of them had not previously been isolated from a Catharanthus species.  相似文献   

8.
Human and animal infections of the fungus Cryptococcus gattii have been recognized in Oregon since 2006. Transmission is primarily via airborne environmental spores and now thought to be locally acquired due to infection in non-migratory animals and humans with no travel history. Previous published efforts to detect C. gattii from tree swabs and soil samples in Oregon have been unsuccessful. This study was conducted to determine the presence of C. gattii in selected urban parks of Oregon cities within the Willamette Valley where both human and animal cases of C. gattii have been diagnosed. Urban parks were sampled due to spatial and temporal overlap of humans, companion animals and wildlife. Two of 64 parks had positive samples for C. gattii. One park had a positive tree and the other park, 60 miles away, had positive bark mulch samples from a walkway. Genotypic subtypes identified included C. gattii VGIIa and VGIIc, both considered highly virulent in murine host models.  相似文献   

9.
We applied whole-genome sequencing to reconstruct the spatial and temporal dynamics underpinning the expansion of Clostridium difficile ribotype 027 in Germany. Based on re-sequencing of genomes from 57 clinical C. difficile isolates, which had been collected from hospitalized patients at 36 locations throughout Germany between 1990 and 2012, we demonstrate that C. difficile genomes have accumulated sequence variation sufficiently fast to document the pathogen''s spread at a regional scale. We detected both previously described lineages of fluoroquinolone-resistant C. difficile ribotype 027, FQR1 and FQR2. Using Bayesian phylogeographic analyses, we show that fluoroquinolone-resistant C. difficile 027 was imported into Germany at least four times, that it had been widely disseminated across multiple federal states even before the first outbreak was noted in 2007, and that it has continued to spread since.  相似文献   

10.
Gram-positive bacteria of the genus Exiguobacterium have been repeatedly isolated from Siberian permafrost ranging in age from 20,000 to 2 to 3 million years and have been sporadically recovered from markedly diverse habitats, including microbial mats in Lake Fryxell (Antarctic), surface water, and food-processing environments. However, there is currently no information on genomic diversity of this microorganism or on the physiological strategies that have allowed its survival under prolonged freezing in the permafrost. Analysis of the genome sequence of the most ancient available Exiguobacterium isolate (Exiguobacterium sp. strain 255-15, from 2 to 3 million-year-old Siberian permafrost) revealed numerous putative transposase sequences, primarily of the IS200/IS605, IS30, and IS3 families, with four transposase families identified. Several of the transposase genes appeared to be part of insertion sequences. Southern blots with different transposase probes yielded high-resolution genomic fingerprints which differentiated the different permafrost isolates from each other and from the Exiguobacterium spp. type strains which have been derived from diverse surface habitats. Each of the Exiguobacterium sp. strain 255-15 transposases that were used as probes had highly conserved homologs in the genome of other Exiguobacterium strains, both from permafrost and from modern sites. These findings suggest that, prior to their entrapment in permafrost, Exiguobacterium isolates had acquired transposases and that conserved transposases are present in Exiguobacterium spp., which now can be isolated from various modern surface habitats.  相似文献   

11.
The ability of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus administered in yogurt to survive the passage through the upper gastrointestinal tract was investigated with Göttingen minipigs that were fitted with ileum T-cannulas. After ingestion of yogurt containing viable microorganisms, ileostomy samples were collected nearly every hour beginning 3 h after food uptake. Living L. delbrueckii subsp. bulgaricus and S. thermophilus were detected in the magnitude of 106 to 107 per gram of intestinal contents (wet weight) in all animals under investigation. A calculation of the minimum amount of surviving bacteria that had been administered is presented. Total DNA extracted from ileostomy samples was subjected to PCR, which was species specific for L. delbrueckii and S. thermophilus and subspecies specific for L. delbrueckii subsp. bulgaricus. All three bacterial groups could be detected by PCR after yogurt uptake but not after uptake of a semisynthetic diet. One pig apparently had developed an endogenous L. delbrueckii flora. When heat-treated yogurt was administered, L. delbrueckii was detected in all animals. S. thermophilus or L. delbrueckii subsp. bulgaricus was not detected, indicating that heat-inactivated cells and their DNAs had already been digested and their own L. delbrueckii flora had been stimulated for growth.  相似文献   

12.
Four Achillea species collected from Turkey and Egypt have been shown to contain a mixture of C-glycosylflavones in their aerial parts. In addition A. fragrantissima and A. lycaonica had such compounds in their roots: these were absent from A. spinulifolia and A. aleppica.  相似文献   

13.
Rhizobium strains used in inoculants for Trifolium spp., Medicago spp., Glycine max, and Lotus pedunculatus were isolated from nodules of these legumes grown in soils into which the rhizobia had been introduced 4 to 8 years before. Isolations were made from a total of 420 nodules. Nodule occupancy by the inoculant strains varied from 17.7% for a soybean strain to 100% in the case of L. pedunculatus whose specific rhizobia did not occur in the soils studied. In general, inoculant strains isolated from nodules did not differ in effectiveness from cultures of the same strains concurrently maintained in lyophilized form. The average effectiveness of all of the isolates (identified and unidentified) from a legume was 7.1 to 73.3% higher than that of the unidentified isolates alone, demonstrating the prolonged effect that a single-seed inoculation has on the rhizobial population in a soil which had not been planted with legumes before. Relatively weak recovery of a Rhizobium japonicum strain introduced into soil 4 years after soybean seed inoculated with a different strain had been planted in the same soil confirmed the advantage of a resident population over an introduced inoculant strain.  相似文献   

14.
Ditrichum austrogeorgicum (Card.) Seppelt, a species originally described in 1906 from South Georgia as Pseudodistichium austrogeorgicum Card., is considered to be conspecific with Ditrichum hyalinum (Mitt.) O. Kuntze. The latter had been first described in 1859 as Leptotrichum hyalinum Mitt. from material collected on the Falkland Islands and Hermite Island near Cape Horn, but it had been first recognized as a separate taxon, Didymodon longifolius (Brid.) Hook. f. & Wils. var. tenuifolius Hook. f. & Wils., in 1847. Pseudodistichium austrogeorgicum f. brevifolium Card. and P. austrogeorgicum var. longifolium Broth. in Card. & Broth. are reduced to synonymy with Ditrichum hyalinum. Some details of the type material of the last are illustrated.  相似文献   

15.
《Journal of Asia》2022,25(4):101987
Mitochondrial genomes (mitogenomes) have been used widely in comparative and evolutionary genomics, molecular evolution, phylogenetics, and population genetics, but very limited information is available for the family Cynipidae. In this report, we described the mitogenome of Andricus mairei. The mitogenome of A. mairei was 16,514 bp in length and contained a typical set of 37 genes. Two control regions (CRs) were detected, one being a partial reverse repeat of the other. In a comparison with the putative ancestral mitogenome, gene rearrangements were found in transfer RNA (tRNA) genes, protein-coding genes and ribosomal RNA (rRNA) genes. Consistent with other Cynipidae species, the gene rearrangement of A. mairei had four obvious characteristics: trnE and trnF had inverted and swapped positions; rrnL and rrnS genes had moved into the cob–nad1 junction; a novel tRNA gene cluster trnL1–trnI–trnL2–trnW–trnM–trnQ had been formed between nad1 and nad2; and trnV had inverted and moved to the nad2cox1 gene junction. Furthermore, A. mairei had two types of mitochondrial circular DNA molecules. Type II differed from type I in an inverted rearrangement of a large fragment of 3349 nucleotides, including two CRs and two rRNA genes.  相似文献   

16.
Regular, membrane-bound crystals of calcium citrate are secreted by a special gland in adult female Sphodromantis lineola, and reach a size of ca. 10 μm long by ca. 5 μm wide and ca. 4 μm high before they are extruded into the oötheca at each oviposition. Substantially larger, but still regular, crystals were obtained from the glands of insects which had been injected with laboratory prepared calcium or magnesium citrate, and from glands which had been artificially prevented from extruding their contents for extended periods (e.g. up to 70 days). Enlarged crystals retain the membranes which are probably responsible for maintaining the characteristic trapeziform shape.  相似文献   

17.
Axis patterning and appendage development have been well studied in Drosophila melanogaster, a species in which both limb and segment morphogenesis are derived. In Drosophila, positional information from genes important in anteroposterior and dorsoventral axis formation, including wingless (wg) and decapentaplegic (dpp), is required for allocating and patterning the appendage primordia. We used RNA interference to characterize the functions of wg and dpp in the red flour beetle, Tribolium castaneum, which retains more ancestral modes of limb and segment morphogenesis. We also characterized the expression of potential targets of the WG and DPP signaling pathways in these embryos. Tribolium embryos in which dpp had been downregulated had defects in the dorsalmost body wall, but did not appear to have been globally repatterned and had normal appendages. Downregulation of wg led to the loss of segment boundaries, gnathal and thoracic appendages, and lateral head lobes, and to changes in the expression of dpp, Distal-less, and Engrailed. The functions of wg varied along both the anteroposterior and dorsoventral axes of the embryo. Phylogenetic comparisons indicate that the role of WNT signaling in segment boundary formation is evolutionarily old, but that its role in appendage allocation originated in the common ancestor of holometabolous insects.  相似文献   

18.
Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd) infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9%) of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans), all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9%) was significantly lower than that found in other anurans (7.3%). The prevalence of infection (30%) in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x 2 = 106.407, P<0.001). This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further.  相似文献   

19.
Five endemic species of Euphorbiaceae have been investigated. Aleuritolic acid and its derivatives were isolated from P. thwaitesii. A. cardiosperma had friedelan derivatives. The Glochidion species contained the same triterpenes, viz. glochidonol, lup-20(29)-ene-3α,23-diol and glochidiol. The bark extractives of a new Glochidion species had, in addition, glochidone and probably lup-20(29)-ene-1α,3α,23-triol. The latter is a new natural product. Glochidone was isolated for the first time outside the genus Glochidion from Bridelia moonii.  相似文献   

20.
Ribulose-1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39) was crystallized from a heterozygous tobacco (Nicotiana tabacum L.) aurea mutant (Su/su), its wild-type sibling (su/su), and green revertant plants regenerated from green spots found on leaves of haploid Su plants. No differences were found in the specific activity or kinetic parameters of this enzyme, when comparing Su/su and su/su plants of the same age, which had been grown under identical conditions. The enzyme crystallized from revertant plants was also identical to the enzyme from wild-type plants with the exception of one clone, designated R2. R2 has a chromosome number approximately double that of the wild-type (87.0 ± 11.1 versus 48). The enzyme from R2 had a lower Vmax for CO2, although the Km values were identical to those for the enzyme from the wild-type plant. The enzyme from all mutant plants had identical isoelectric points, identical molecular weight as demonstrated by migration on native and sodium dodecyl sulfate (SDS)-polyacrylamide gels, and the same ratio of large to small subunits as the enzyme from the wild-type. The large subunit of the enzyme from tobacco leaves exhibited a different electrophoretic pattern than did the large subunit from spinach; there were two to three bands on SDS-polyacrylamide gels for the tobacco enzyme whereas the enzyme from spinach had only one species of large subunit.  相似文献   

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