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1.
2.
On the basis of the DNA–DNA hybridization patterns and phenotypic characteristics, Fusobacterium nucleatum was classified into five subspecies. Previous studies have suggested that F. nucleatum subsp. vincentii is genetically similar to F. nucleatum subsp. fusiforme. The aim of this study was to investigate the possibility of classifying these two subspecies into a single subspecies by phylogenetic analysis using a single sequence (24,715 bp) concatenated 22 housekeeping genes of eight F. nucleatum strains including type strains of five F. nucleatum subspecies. The phylogenetic analysis indicated that F. nucleatum subsp. vincentii and F. nucleatum subsp. fusiforme were clustered in the same group and each strain of other F. nucleatum subspecies were also separated into the same cluster. These results suggested that F. nucleatum subsp. fusiforme and F. nucleatum subsp. vincentii can be classified into a single subspecies. F. nucleatum subsp. vincentii was early published name; therefore, F. nucleatum subsp. fusiforme Gharbia and Shah 1992 can be regarded as a later synonym of F. nucleatum subsp. vincentii Dzink et al. 1990.  相似文献   

3.
A lysozyme sensitive strain of B. thuringiensis (strain O 016) was isolated and shown to be effectively transformed with plasmids pC 194 and pHV 33 using the protoplast transformation technique. The plasmid pC 194 from one successful transformant, strain O 016–194, was subsequently transferred to B. thuringiensis subsp. israelensis by a “conjugation-like” process. The plasmid pBC 16 from B. cereus could also be transferred to B. thuringiensis subsp. israelensis with high frequency using the conjugation-like process. Further, both plasmids, pC 194 and pBC 16, were transferred between strains of B. thuringiensis subsp. israelensis to yield transcipient strains that harbored and expressed properties of both plasmids. This work constitutes effective gene transfer system in B. thuringiensis subsp. israelensis.  相似文献   

4.
A comparative chemical analysis of Agastache mexicana subsp. mexicana and A. mexicana subsp. xolocotziana reveals that their methanol extracts constituents were very similar, with acacetin and (2-acetyl)-7-O-glucosyl acacetin being the most abundant compounds obtained. These results are consistent with the information reported for other species of Agastache. However, GS-MS analyses showed that methyl chavicol, limonene and linalool were the main constituents of the essential oils of A. mexicana subsp. mexicana, while pulegone, menthone and isopulegone were the major constituents found in A. mexicana subsp. xolocotziana. Furthermore, a different composition was found in their respective hexane extracts. These chemical composition dissimilarities between the two taxa support their recognition as distinct subspecies.  相似文献   

5.
The objective of this study was to develop the strain-specific PCR primers for Fusobacterium nucleatum subsp. fusiforme ATCC 51190T and F. nucleatum subsp. vincentii ATCC 49256T based on the nucleotide sequence of the Fs17 and Fv35 DNA probes, respectively. The strain specificity was tested against 10 type strains of Fusobacterium spp. or subsp., 21 clinical isolates of F. nucleatum from Koreans, and five type strains of distinct Fusobacterium species. Primer sensitivity was determined by testing serial dilutions (4 ng–4 fg) of the purified genomic DNA from each of the type strains. PCR showed that two pairs of PCR primers, Fs17-F14/Fs17-R14 and Fv35-F1/Fv35-R1 primers, could produce strain-specific amplicons from F. nucleatum subsp. fusiforme ATCC 51190T and F. nucleatum subsp. vincentii ATCC 49256T, respectively. The two PCR primer sets could detect as little as 0.4 pg or 4 pg of the genomic DNA of each target strain. These results suggest that the two sets of PCR primers could be used to identify F. nucleatum subsp. fusiforme ATCC 51190T and F. nucleatum subsp. vincentii ATCC 49256T, particularly for ascertaining the authenticity of the strain.  相似文献   

6.
Mycobacterium avium subsp. paratuberculosis causes Johne''s disease (JD) in ruminants, with substantial economic impacts on the cattle industry. Johne''s disease is known for its long latency period, and difficulties in diagnosis are due to insensitivities of current detection methods. Eradication is challenging as M. avium subsp. paratuberculosis can survive for extended periods within the environment, resulting in new infections in naïve animals (W. Xu et al., J. Environ. Qual. 38:437-450, 2009). This study explored the use of a biosecure, static composting structure to inactivate M. avium subsp. paratuberculosis. Mycobacterium smegmatis was also assessed as a surrogate for M. avium subsp. paratuberculosis. Two structures were constructed to hold three cattle carcasses each. Naturally infected tissues and ground beef inoculated with laboratory-cultured M. avium subsp. paratuberculosis and M. smegmatis were placed in nylon and plastic bags to determine effects of temperature and compost environment on viability over 250 days. After removal, samples were cultured and growth of both organisms was assessed after 12 weeks. After 250 days, M. avium subsp. paratuberculosis was still detectable by PCR, while M. smegmatis was not detected after 67 days of composting. Furthermore, M. avium subsp. paratuberculosis remained viable in both implanted nylon and plastic bags over the composting period. As the compost never reached a homogenous thermophilic (55 to 65°C) state throughout each structure, an in vitro experiment was conducted to examine viability of M. avium subsp. paratuberculosis after exposure to 80°C for 90 days. Naturally infected lymph tissues were mixed with and without compost. After 90 days, M. avium subsp. paratuberculosis remained viable despite exposure to temperatures typically higher than that achieved in compost. In conclusion, it is unlikely composting can be used as a means of inactivating M. avium subsp. paratuberculosis associated with cattle mortalities.  相似文献   

7.
Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene of L. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp. delbrueckii LMG 6412T, which clustered with L. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains.  相似文献   

8.
Eleven alkylphenols were isolated from the aerial parts of Dactylis glomerata subsp. hispanica, six of them described for the first time. The structural characterization of these compounds has been elucidated by 1D and 2D NMR techniques. The fragmentation patterns of the metabolites obtained by GC–MS analysis allowed the side chain to be elucidated. The allelopathic potential of three alkylphenols, representative of each homologous series of alkylphenols from D. glomerata subsp. hispanica, has been assayed on D. glomerata subsp. hispanica and an herbaceous coexisting species, Phleum subulatum. The bioassay results showed a high auto-stimulation values of germination and root and shoot elongation for D. glomerata subsp. hispanica at high concentrations.  相似文献   

9.
With the objective of contributing to understanding the patterns of variation within the Turnera sidoides complex, a detailed evaluation of morphological variation along the range of T. sidoides subsp. pinnatifida was performed. A multivariate analysis based on leaf traits and flower colour data enabled differentiation of five morphotypes. Common-garden experiments demonstrated that the morphological variants have a strong genetic basis. It was also found that the morphotypes are geographically structured along the subspecies range, display different habitat preferences, and occur in regions with different climatic regimes. Although these results are suggestive of adaptive differentiation of T. sidoides subsp. pinnatifida, comparisons between morphological and bioclimatic ordinations showed that the patterns observed cannot be fully explained by current climatic conditions. It is proposed that Miocene–Pleistocene events may explain the origin of the five morphotypes and that current climatic and ecological factors may be contributing to the maintenance of the extent and patterns of morphological differentiation in T. sidoides subsp. pinnatifida.  相似文献   

10.
Two deltaproteobacterial sulfate reducers, designated strain I.8.1T and I.9.1T, were isolated from the oxygen minimum zone water column off the coast of Peru at 400 and 500 m water depth. The strains were Gram-negative, vibrio-shaped and motile. Both strains were psychrotolerant, grew optimally at 20°C at pH 7.0–8.0 and at 2.5–3.5% NaCl (w/v). The strains grew by utilizing hydrogen/acetate, C3–4 fatty acids, amino acids and glycerol as electron acceptors for sulfate reduction. Fumarate, lactate and pyruvate supported fermentative growth. Sulfate, sulfite, thiosulfate and taurin supported growth as electron acceptors. Both strains were catalase-positive and highly oxygen-tolerant, surviving 24 days of exposure to atmospheric concentrations. MK6 was the only respiratory quinone. The most prominent cellular fatty acid was iso-17:1-ω9c (18%) for strain I.8.1T and iso-17:0-ω9c (14%) for strain I.9.1T. The G+C contents of their genomic DNA were 45–46 mol%. Phylogenetic analysis of 16S rRNA and dsrAB gene sequences showed that both strains belong to the genus Desulfovibrio. Desulfovibrio acrylicus DSM 10141T and Desulfovibrio marinisediminis JCM 14577T represented their closest validly described relatives with pairwise 16S rRNA gene sequence identities of 98–99%. The level of DNA-DNA hybridization between strains I.8.1T and I.9.1T was 30–38%. The two strains shared 10–26% DNA-DNA relatedness with D. acrylicus. Based on a polyphasic investigation it is proposed that strains I.8.1T and I.9.1T represent a novel species for which the name Desulfovibrio oceani sp. nov. is proposed with the two subspecies D. oceani subsp. oceani (type strain, I.8.1T = DSM 21390T = JCM 15970T) and D. oceani subsp. galateae (type strain, I.9.1T = DSM 21391T = JCM 15971T).  相似文献   

11.
《Phytochemistry》1986,25(6):1443-1447
Two novel alkaloids 3β,4α,13α-trihydroxylupanine and 3β,4α-dihydroxy 13α-O-(2'-pyrrolylcarbonyl)-lupanine (calpaurine) have been isolated from the leaves of Ethiopian Calpurnia aurea subsp. aurea. In addition, lupinine and epilupinine (both new for the genus), calpurmenine and calpurmenine pyrrolecarboxylic acid ester (previously found in subsp. sylvatica but not in subsp. aruea) have been isolated together with 13-hydroxylupanine, its tiglate and pyrrolecarboxylic acid esters (calpumine), virgiline and virgiline pyrrolecarboxylic acid ester, alkaloids which have been reported previously from subsp. aruea.  相似文献   

12.
Repeated exposure in the field followed by laboratory selection produced 1,800- to >6,800-fold resistance to formulations of Bacillus thuringiensis subsp. kurstaki in larvae of the diamondback moth, Plutella xylostella. Four toxins from B. thuringiensis subsp. kurstaki [CryIA(a), CryIA(b), CryIA(c), and CryIIA] caused significantly less mortality in resistant larvae than in susceptible larvae. Resistance to B. thuringiensis subsp. kurstaki formulations and toxins did not affect the response to CryIC toxin from B. thuringiensis subsp. aizawai. Larvae resistant to B. thuringiensis subsp. kurstaki showed threefold cross-resistance to formulations of B. thuringiensis subsp. aizawai containing CryIC and CryIA toxins. This minimal cross-resistance may be caused by resistance to CryIA toxins shared by B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai.  相似文献   

13.
A Multivariate Morphon Analysis (MMA) of Coccolithus pelagicus (s. l.) coccoliths was performed on 178 samples from an oceanic core recovered off the Portuguese margin (MD95-2040), in order to define the morphometric boundaries of its morphotypes and their behaviour during the last two glacial cycles. The recurrent occurrence of the smaller morphotype of this taxon, C. pelagicus subsp. pelagicus, was recognized for the first time off the Portuguese coast. Three sections, around Heinrich Layers 1 and 6 and Termination II-Eemian, were selected to establish high resolution comparisons between C. pelagicus subsp. pelagicus and C. pelagicus subsp. braarudii and two independent proxies for cold water masses: the records of the planktonic foraminifera Neogloboquadrina pachyderma (sinistral) and ice-rafted detritus (IRD). There is an overall negative correlation between C. pelagicus subsp. pelagicus and C. pelagicus subsp. braarudii as expressed by MMA Factor 1, the scores of which respond similarly to those of two non-cocolithophore proxies and consequently, is proposed as a calcareous nannoplankton proxy for the influence of subpolar waters in the region. Detailed analysis, however, showed occasional decoupling amongst these three proxies, which are used to highlight significant changes between the cooling–warming sequences of distinct events off Iberia.  相似文献   

14.
A thiosulfate-oxidizing facultative chemolithoautotrophic Burkholderia sp. strain ATSB13T was previously isolated from rhizosphere soil of tobacco plant. Strain ATSB13T was aerobic, Gram-staining-negative, rod shaped and motile by means of sub-terminal flagellum. Strain ATSB13T exhibited mixotrophic growth in a medium containing thiosulfate plus acetate. A phylogenetic study based on 16S rRNA gene sequence analysis indicated that strain ATSB13T was most closely related to Burkholderia kururiensis KP23T (98.7%), Burkholderia tuberum STM678T (96.5%) and Burkholderia phymatum STM815T (96.4%). Chemotaxonomic data [G+C 64.0 mol%, major fatty acids, C18:1 ω7c (28.22%), C16:1 ω7c/15 iso 2OH (15.15%), and C16:0 (14.91%) and Q-8 as predominant respiratory ubiquinone] supported the affiliation of the strain ATSB13T within the genus Burkholderia. Though the strain ATSB13T shared high 16S rRNA gene sequence similarity with the type strain of B. kururiensis but considerably distant from the latter in terms of several phenotypic and chemotaxonomic characteristics. DNA–DNA hybridization between strain ATSB13T and B. kururiensis KP23T was 100%, and hence, it is inferred that strain ATSB13T is a member of B. kururiensis. On the basis of data obtained from this study, we propose that B. kururiensis be subdivided into B. kururiensis subsp. kururiensis subsp. nov. (type strain KP23T = JCM 10599T = DSM 13646T) and B. kururiensis subsp. thiooxydans subsp. nov. (type strain ATSB13T = KACC 12758T).  相似文献   

15.
Paratuberculosis, or Johne''s disease, in cattle is caused by Mycobacterium avium subsp. paratuberculosis, which has recently been suspected to be transmitted through dust. This longitudinal study on eight commercial M. avium subsp. paratuberculosis-positive dairy farms studied the relationship between the number of cows with M. avium subsp. paratuberculosis antibody-positive milk and the presence of viable M. avium subsp. paratuberculosis in settled-dust samples, including their temporal relationship. Milk and dust samples were collected in parallel monthly for 2 years. M. avium subsp. paratuberculosis antibodies in milk were measured by enzyme-linked immunosorbent assay (ELISA) and used as a proxy for M. avium subsp. paratuberculosis shedding. Settled-dust samples were collected by using electrostatic dust collectors (EDCs) at six locations in housing for dairy cattle and young stock. The presence of viable M. avium subsp. paratuberculosis was identified by liquid culture and PCR. The results showed a positive relationship (odds ratio [OR], 1.2) between the number of cows with ELISA-positive milk and the odds of having positive EDCs in the same airspace as the adult dairy cattle. Moreover, the total number of lactating cows also showed an OR slightly above 1. This relationship remained the same for settled-dust samples collected up to 2 months before or after the time of milk sampling. The results suggest that removal of adult cows with milk positive for M. avium subsp. paratuberculosis-specific antibody by ELISA might result in a decrease in the presence of viable M. avium subsp. paratuberculosis in dust and therefore in the environment. However, this decrease is likely delayed by several weeks at least. In addition, the data support the notion that M. avium subsp. paratuberculosis exposure of young stock is reduced by separate housing.  相似文献   

16.
Thirteen coagulase-negative, oxidase-negative, and novobiocin-susceptible staphylococci were isolated from human clinical specimens. The isolates were differentiated from known staphylococcal species on the basis of 16S rRNA, hsp60, rpoB, dnaJ, tuf, and gap gene sequencing, automated ribotyping, (GTG)5-PCR fingerprinting, and MALDI-TOF MS analysis. Phylogenetic analysis based on the 16S rRNA gene sequence indicated phylogenetic relatedness of the analyzed strains to Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus devriesei, and Staphylococcus lugdunensis. DNA–DNA hybridization experiments between representative strains CCM 8418T, CCM 8421T, and the closest phylogenetic neighbors confirmed that the isolates represent novel Staphylococcus species, for which the name Staphylococcus petrasii sp. nov. is proposed. Genotypic and phenotypic analyses unambiguously split the strains into two closely related subclusters. Based on the results, two novel subspecies S. petrasii subsp. petrasii subsp. nov. and S. petrasii subsp. croceilyticus subsp. nov. are proposed, with type strains CCM 8418T (=CCUG 62727T) and CCM 8421T (=CCUG 62728T), respectively.  相似文献   

17.
Here, we present for the first time a high-affinity peptide nucleic acid (PNA) oligonucleotide sequence for detecting Mycobacterium avium bacteria, including the opportunistically pathogenic subspecies M. avium subsp. avium, M. avium subsp. paratuberculosis, and M. avium subsp. silvaticum, by the fluorescence in situ hybridization (FISH) method. There is evidence that M. avium subsp. avium especially is able to survive and grow in drinking-water biofilms and possibly transmit via drinking water. The designed PNA probe (MAV148) specificity was tested with several bacterial species, including other mycobacteria and mycolic acid-containing bacteria. From the range of bacterial strains tested, only M. avium subsp. avium and M. avium subsp. paratuberculosis strains were hybridized. The PNA FISH method was applied successfully to detect M. avium subsp. avium spiked in water samples and biofilm established within a Propella biofilm reactor fed with potable water from a distribution supply.  相似文献   

18.
The plant-pathogenic bacterium Xanthomonas citri subsp. citri is the causal agent of Asiatic citrus canker, a serious disease that affects all the cultivars of citrus in subtropical citrus-producing areas worldwide. There is no curative treatment for citrus canker; thus, the eradication of infected plants constitutes the only effective control of the spread of X. citri subsp. citri. Since the eradication program in the state of São Paulo, Brazil, is under threat, there is a clear risk of X. citri subsp. citri becoming endemic in the main orange-producing area in the world. Here we evaluated the potential use of alkyl gallates to prevent X. citri subsp. citri growth. These esters displayed a potent anti-X. citri subsp. citri activity similar to that of kanamycin (positive control), as evaluated by the resazurin microtiter assay (REMA). The treatment of X. citri subsp. citri cells with these compounds induced altered cell morphology, and investigations of the possible intracellular targets using X. citri subsp. citri strains labeled for the septum and centromere pointed to a common target involved in chromosome segregation and cell division. Finally, the artificial inoculation of citrus with X. citri subsp. citri cells pretreated with alkyl gallates showed that the bacterium loses the ability to colonize its host, which indicates the potential of these esters to protect citrus plants against X. citri subsp. citri infection.  相似文献   

19.
The occurrence of the acmA gene, encoding the lactococcal N-acetylmuramidase in new lactococcal isolates from raw milk cheeses, has been determined. Isolates were genotypically identified to the subspecies level with a PCR technique. On the basis of PCR amplification of the acmA gene, the presence or absence of an additional amplicon of approximately 700 bp correlated with Lactococcus lactis subspecies. L. lactis subsp. lactis exhibits both the expected 1,131-bp product and the additional amplicon, whereas L. lactis subsp. cremoris exhibits a single 1,131-bp fragment.  相似文献   

20.

Background

Mycobacterium avium is the principal etiologic agent of non-tuberculous lymphadenitis in children. It is also a known pathogen for birds and other animals. Genetic typing of M. avium isolates has led to a proposal to expand the set of subspecies to include M. avium subsp. hominissuis. Isolates associated with disease in humans belong to this subspecies.

Methodology/Principal Findings

Peripheral blood mononuclear cells from six healthy blood donors were stimulated in vitro with ten isolates of M. avium avium and 11 isolates of M. avium hominissuis followed by multiplex bead array quantification of cytokines in supernatants. M. avium hominissuis isolates induced significantly more IL-10 and significantly less IL-12p70, TNF, IFN-γ and IL-17 when compared to M. avium avium isolates. All strains induced high levels of IL-17, but had very low levels of IL-12p70.

Conclusion/Significance

The strong association between M. avium subsp. hominissuis and disease in humans and the clear differences in the human immune response to M. avium subsp. hominissuis compared to M. avium subsp. avium isolates, as demonstrated in this study, suggest that genetic differences between M. avium isolates play an important role in the pathogenicity in humans.  相似文献   

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