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1.
Repeat induced point mutation (RIP) is a gene silencing mechanism present in fungal genomes. During RIP, duplicated sequences
are efficiently and irreversibly mutated by transitions from C:G to T:A. For the first time, we have identified traces of
RIP in transposable elements of Aspergillus niger and Penicillium chrysogenum, two biotechnologically relevant fungi. We found that RIP in P. chrysogenum has affected a large set of sequences, which also contain other mutations. On the other hand, RIP in A. niger is limited to only few sequences, but literally all mutations are RIP-like. Surprisingly, RIP occurred only in transposon
sequences that have disrupted open reading frames in A. niger, a phenomenon not yet reported for other fungi. In both fungal species, we identified two sequences with strong sequence
similarity to Neurospora crassa RID. RID is a putative DNA methyltransferase and the only known enzyme involved in the RIP process. Our findings suggest
that both A. niger and P. chrysogenum either had a sexual past or have a sexual potential. These findings have important implications for future strain development
of these fungi. 相似文献
2.
N. V. Fomenko V. Yu. Borgoyakov V. V. Panov 《Molecular Genetics, Microbiology and Virology》2011,26(2):60-65
16S rRNA, p66 and glpQ gene fragments in Borrelia miyamotoi transmitted by Ixodes persulcatus are determined and analyzed. Specific nucleotide sequences of every locus have been shown to be identical. The highest homology
level for nucleotide sequences of three loci has been shown for the sequences of strains isolated earlier in Japan. An analysis
of the P66 protein amino-acid sequence has shown that the locus corresponding to the surface-exposed domain differs considerably
from both Borrelia hermsii, a typical member of tick-borne relapsing fever and Borrelia lonestari, the closest related species. Three genetic variants of Borrelia miyamotoi P66 protein is characterized not only by amino-acid substitutions, but also by deletions. 相似文献
3.
Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails. 相似文献
4.
Karina?M.?Rebello Luzia?M.?C.?C?rtes Bernardo?A.?S.?Pereira Bernardo?M.?O.?Pascarelli Suzana?C?rte-Real Léa?C.?Finkelstein Rosa?T.?Pinho Claudia?M.?d’Avila-Levy Carlos?R.?Alves 《Parasitology research》2009,106(1):95-104
Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and
is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we
obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of
63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the
peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data
together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation
of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant
and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that
some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues
in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection. 相似文献
5.
Pepo aphid-borne yellows virus (PABYV) has been proposed as a putative representative of a new species in the genus Polerovirus in the family Luteoviridae. The genomes of two South African (SA) isolates of cucurbit-infecting PABYV were described in this record. Total RNA, extracted from a pattypan (Cucurbita pepo L.) and a baby marrow (C. pepo L.) leaf samples, was subjected to next-generation sequencing (NGS) on the HiSeq Illumina platform. Sanger sequencing was subsequently used to authenticate the integrity of PABYV’s genome generated from de novo assembly of the NGS data. PABYV genome of SA isolates consists of 5813 nucleotides and displays an organisation typical of poleroviruses. Genome sequence comparisons of the SA PABYV isolates to other poleroviruses support the classification of PABYV as a new species in the genus Polerovirus. Recombination analyses showed that PABYV and Cucurbit aphid-borne yellows virus (CABYV) shared the same ancestor for the genome part situated between breaking points. Phylogenetic analyses of the RNA-dependent RNA polymerase and the coat protein genes showed that SA PABYV isolates shared distant relationship with CABYV and Suakwa aphid-borne yellows virus. Based on our results, we propose that PABYV is a distinct species in the genus Polerovirus. 相似文献
6.
7.
Sharareh Najafian Mojtaba Moradi Masood Sepehrimanesh 《Comparative clinical pathology》2016,25(4):743-747
Mentha piperita (peppermint) and Stevia rebaudiana (stevia) are now widespread in cultivation worldwide. However, reports about the contents of these two plant species are scarce. To establish the polyphenolic contents and antioxidant activity of these plants by ferric ion-reducing activity (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods, local plants were harvested in flowering stage. Samples without any previous treatments were analyzed using high-performance liquid chromatography (HPLC) to determine the polyphenolic contents. Also, their antioxidant properties were determined using FRAP and DPPH methods. Six phenolic compounds including quercetin, p-coumaric acid, trans-ferulic acid, hesperidin, hesperetin, and rosmarinic acid were identified and quantified in peppermint. However, hesperidin, eugenol, coumarin, and vanillin were the most component in stevia. Peppermint showed better antioxidant properties than stevia in both FRAP and DPPH assessments. Our findings demonstrated that these two plants contain high polyphenolic compounds and are potent antioxidant species. Further studies on the therapeutic properties of these plants in animal and human models of diseases are recommended. 相似文献
8.
Edílson Damke Joyce K Tsuzuki Diógenes AG Cortez Izabel CP Ferreira Thâmara A Bertoni Márcia R Batista Lucélia Donati Terezinha IE Svidzinski Márcia EL Consolaro 《BMC complementary and alternative medicine》2011,11(1):35
Background
Study of in vivo antifungal activity of the hydroalcoholic extract (HE) and n-BuOH extract (BUTE) of Sapindus saponaria against azole-susceptible and -resistant human vaginal Candida spp. 相似文献9.
10.
María del Rosario Robles James E. Loudon John M. Kinsella Mandala Hunter-Ishikawa David S. Miller Michelle L. Sauther Frank P. Cuozzo 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2010,55(3):270-275
Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and
the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini
hosts will only be proven when additional records fill in the gaps in their distribution. 相似文献
11.
Sina Kirsanovs Boris Klempa Renate Franke Min-Hi Lee Günther Schönrich Andreas Rang Detlev H. Kruger 《Virus genes》2010,41(3):319-328
The tri-segmented RNA genome of hantaviruses facilitates genetic reassortment by segment swapping when cells are co-infected
with different virus strains. We found efficient in vitro reassortment between members of two different genetic lineages of
the Dobrava-Belgrade virus species, the weakly virulent DOBV-Aa and highly virulent DOBV-Af. In all reassortants, S and L segments originated from the
same parental strain, and only the M segment was exchanged. To identify functional differences between the parental strains
DOBV-Aa and DOBV-Af in cell culture and to compare them with the reassortants, we studied elements of the innate immunity
in virus-infected cells. The contrasting phenotypes of the parental viruses were maintained by the reassortants carrying the
respective S and L segments of the parental virus and were not influenced by the origin of the M segment. 相似文献
12.
B. Verriere B. Sabatier E. Carbonnelle J. l. Mainardi P. Prognon I. Whitaker L. Lantieri M. Hivelin 《European journal of clinical microbiology & infectious diseases》2016,35(6):1001-1006
While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern. Aeromonas spp. strains are involved in the majority of reported cases. As surgical success rate is directly impacted, an adapted antibiotic prophylaxis should be instituted in order to minimize these complications. We assessed pharmaceutical process, microbiological control and related infections in order to provide data and choose the appropriate antibiotherapy for patients requiring MLT. We report a clinical and microbiological study over a 24-month period. Clinical data were collected from patients’ database, and microbiological analysis both on leeches’ tank water and crushed leeches were performed to characterize isolated strains and their susceptibility to antibiotics. A total of 595 leeches were used to treat 28 patients (12 in plastic surgery and 16 in orthopaedic surgery), and three documented cases of post-operative infections were reported. Aeromonas spp. isolates yielded from 62 % of analyzed batches (75 % of Aeromonas veronii). Eighteen Aeromonas spp. isolates yielded from 23 water samples and three crushed leeches. Isolates were similar in tank and crushed leeches. Strains were susceptible to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins but resistant to amoxicillin/clavulanic acid and second-generation cephalosporins. According to collected data, routine tank water microbiological analyses are mandatory in order to identify leeches’ batches containing resistant strains and to discard them. In this context, the surgeon is able to select an appropriated antibiotic prophylaxis in order to avoid MLT associated serious post-operative complications. 相似文献
13.
Bardia A Tiwari SK Gunisetty S Anjum F Nallari P Habeeb MA Khan AA 《Inflammation research》2012,61(4):359-365
Objective
The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC). 相似文献14.
Korsunenko A Chrisanfova G Lopatkin A Beer SA Voronin M Ryskov AP Semyenova SK 《Parasitology research》2012,110(2):833-841
Avian schistosome Trichobilharzia szidati is a member of the largest genus within the family Schistosomatidae (Trematoda). Population genetic structure of Trichobilharzia spp. schistosomes, causative agents of cercarial dermatitis in humans, has not been studied yet. The knowledge of the genetic
structure of trichobilharzian populations is essential for understanding the host–parasite coevolutionary dynamics and epidemiology
strategies. Here we examined genetic diversity in three geographically isolated local populations of T. szidati cercariae inhabiting Russia based on nuclear (randomly amplified polymorphic DNA, RAPD) and mt (cox1) markers. We analyzed T. szidati cercariae shed from seven naturally infected snails of Lymnaea stagnalis. Using three random primers, we demonstrated genetic variation among populations, thus posing genetic structure across geographic
sites. Moreover, T. szidati cercariae have been genetically structured among hosts (infrapopulations). Molecular variance analysis was performed to test
the significance of genetic differentiation within and between local populations. Of total parasitic diversity, 18.8% was
partitioned between populations, whereas the higher contribution (48.9%) corresponds to the differences among individual cercariae
within infrapopulations. In contrast to RAPD markers, a 1,125-bp fragment of cox1 mt gene failed to provide any significant within-species structure. The lack of geographic structuring was detected using
unique haplotypes which were determined in the current work for Moscow and Western Siberian local populations as well as obtained
previously for European isolates (Czech Republic and Germany). All T. szidati/Trichobilharzia ocellata haplotypes were found to be mixed across their geographical origin. 相似文献
15.
Steinernema species are entomopathogenic nematodes associated with Xenorhabdus bacteria. The life cycle of these associations is composed of two stages: (1) a free stage in the soil, where infective juveniles
(IJs), which carry bacteria in their guts, search for new insect hosts; and (2) a parasitic stage, where the IJs infect insects,
release their Xenorhabdus symbionts and reproduce in order to produce new IJs. Previous studies clearly showed benefits to the association for several
Steinernema species during the parasitic stage. Nevertheless, no study has so far explored, during the free stage, the existence of costs
or benefits to the association for different Steinernema. Here, we compared the survival of both symbiotic and aposymbiotic IJs in two nematode species: (1) Steinernema carpocapsae-exhibiting IJs that carry a high number of Xenorhabdus cells in their guts; and (2) its closely relative species, S. scapterisci-exhibiting IJs, that carry very few Xenorhabdus cells in their guts. We showed that the bacterial symbionts were costly for S. carpocapsae by increasing IJs’ mortality but not for S. scapterisci. This difference in cost induced by bacteria to IJs during the free stage could be correlated with the difference in the
numbers of bacteria carried by IJs of each nematode species. 相似文献
16.
Yellow oat-grass plants (Trisetum flavescens L.) with mild mosaic and pronounced dwarfing symptoms were observed at different locations in the Czech Republic. Electron
microscope observations of symptomatic plants revealed the presence of filamentous particles and inclusion bodies characteristic
of the family Potyviridae. The virus was readily mechanically transmitted to its original host plus a narrow host range of monocot species. Serological
assays of infected plant extracts using antiserum specific to the closest species in the family Potyviridae were negative. The 3′ end of the viral genome was cloned, sequenced and compared to sequences of species in the family Potyviridae. The virus is more closely related to viruses in the genus Tritimovirus than to other genera within the Potyviridae. Based on phylogenetic analyses of the coat protein cistron and flanking genomic regions, we propose this is a distinct viral
species of the genus Tritimovirus, tentatively named Yellow oat-grass mosaic virus (YOgMV). 相似文献
17.
A total of 20 random primers (10-mers) were used to amplify RAPD markers from the genomic DNA of four Trypanosoma brucei stocks from East and West Africa, four T. evansi stocks from Africa, Asia and South America and one T. equiperdum stock from Asia. Between 65 and 88 reproducible fragments ranging from 0.25 to 2.15 kb were generated from these stocks depending on the stock/primer combination. The similarity coefficient (SC) among the stocks of T. brucei from Kenya, Nigeria, Tanzania and Zambia ranged from 62.9% to 74.0% (average: 67.6%). The SC among the stocks of T. evansi from Kenya, China and Brazil was 76.4%–95.5% (average: 86.4%), while the SC between T. evansi stock from China and Brazil was 95.5%. For T. evansi and T. equiperdum, the SC among the stocks ranged from 81.2% to 94.4% (average: 87.6%). As for the SC among the stocks of T. brucei and T. evansi, it was found to be from 54.7% to 80.3% (average: 68.0%) and the SC among stocks of T. brucei and T. equiperdum was from 59.4% to 76.9% (average: 68.1%). Our results indicate that the stocks of T. evansi from China and from Brazil are more closely related to the stock of T. equiperdum from China than to the stocks of T. evansi isolated from Kenya and to the stocks of T. brucei. In addition, our results further support the hypothesis that T. evansi stocks from China and Brazil could have arisen from a single lineage. The possible evolution of T. evansi and T. equiperdum is also discussed. 相似文献
18.
Cleide D. Coelho Bruno P. Berto Daniel M. Neves Vinícius M. de Oliveira Walter Flausino Carlos Wilson G. Lopes 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2011,56(3):239-244
Two new coccidian species (Protozoa, Apicomplexa, Eimeriidae) are reported from the saffron finch Sicalis flaveola Linnaeus, 1766, a very common species in South America. Isospora cetasiensis sp. nov. oocysts are subspherical to ellipsoidal, 23.1 × 21.6 μm, with smooth, bilayered wall, ∼1.0 μm. Micropyle, oocyst
residuum and polar granule are absent. Sporocysts are ovoidal, 15.1 × 10.9 μm. Stieda body is knob-like and substieda body
is rounded. Sporocyst residuum is composed of many scattered granules and spherules of different sizes. Sporozoites are vermiform
with one refractile body and a nucleus. Isospora sicalisi sp. nov. oocysts are subspherical to ellipsoidal, 27.5 × 25.2 μm, with a smooth, bilayered wall, ∼1.1 μm. Micropyle, oocyst
residuum and polar granule are absent. Sporocysts are ellipsoidal, 17.2 × 11.7 μm. Stieda body is knob-like and substieda
body is trapezoidal. Sporocyst residuum is composed of scattered granules and spherules of different sizes. Sporozoites are
vermiform with one refractile body and a nucleus. 相似文献
19.
Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include
high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In
P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis.
Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed. 相似文献
20.
Having studied 11 herring gulls (Larus argentatus) Sarcocystis cysts were found in neck and leg muscles of 4 birds. One type of sarcocysts (cyst type I) that have a thin (∼1.0 μm), smooth,
or slightly wavy cyst wall without clearly visible protrusions and small (6.0–8.0 μm) lancet- or banana-shaped cystozoites
was identified by the light microscopy. Sarcocysts extracted from one herring gull were used for electron microscopy and DNA
analysis. Ultrastructurally, Sarcocystis sp. from the herring gull had the same tissue cyst wall type-1 as S. calchasi, S. columbae, and S. wobeseri parasitizing in birds. According to first internal transcribed spacer (ITS-1) region, 18S rRNA and 28S rRNA gene sequences,
Sarcocystis sp. from the herring gull belongs to S. wobeseri. Nevertheless, without evidences of cross-transmission experiment sarcocysts extracted from herring gull at present time
are named as S. wobeseri-like. 相似文献