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1.
Isolated flagellar filaments from the type strain of Bacillus cereus, ATCC 14579, were shown to consist of 34, 32 and 31 kDa proteins in similar proportions as judged by band intensities on sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The N-terminal amino acid sequences of these three proteins of strain ATCC 14579 were identical with the deduced sequences of three flagellin genes BC1657, BC1658 and BC1659 in the whole genome sequence. Strain ATCC 14579 was classified into serotype T2 by a flagellar serotyping scheme for B. cereus strains that are untypeable into known flagellar serotypes H1 to H23. Flagellar filaments from a reference strain of serotype T2 contained two protein bands at 34 and 32 kDa, but a single protein band at 39 kDa was detected in flagellar filaments of a reference strain of serotype H1. Two murine monoclonal antibodies, 1A5 and 2A5, which recognize both the 34 and 32 kDa flagellins and a single flagellin of 32 kDa, respectively, were specifically reactive with B. cereus strains ATCC 14579 and serotype T2 in whole-cell ELISA and bacterial motility inhibition tests. In immunoelectron microscopy with monoclonal antibodies 1A5 and 2A5, colloidal gold spheres were shown to localize almost evenly over the entire part of flagellar filaments. Since strain ATCC 14579, and presumably strain serotype T2, are unusual among B. cereus strains in possessing multiple genes that encode flagellin subunits, a possible unique mechanism may contribute to assembly of multiple flagellin subunits into the filament over its entire length.  相似文献   

2.
Haemophilus parasuis is the cause of Glässer''s disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer''s disease between 1–7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer''s disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and vaccine targets.  相似文献   

3.
The genome size of Actinobacillus pleuropneumoniae was determined by pulsed field gel electrophoresis of AscI and ApaI digested chromosomal DNA. The genome size of the type strain 4074T (serotype 1) was determined to be 2404±40 kb. The chromosome sizes for the reference strains of the other serotypes range between 2.3 and 2.4 Mb. The restriction pattern profiles of AscI, ApaI and NheI digested chromosomes showed a high degree of polymorphism among the different serotype reference strains and allowed their discrimination. The analysis of the macrorestriction pattern polymorphism revealed phylogenetic relationships between the different serotype reference strains which reflect to some extent groups of serotypes known to cross-react serologically. In addition, different pulsed fields gel electrophoresis patterns also revealed heterogeneity in the chromosomal structure among different field strains of serotypes 1, 5a, and 5b, while strains of serotype 9 originating from most distant geographical places showed homogeneous ApaI patterns in pulsed field gel electrophoresis.  相似文献   

4.
Aggregatibacter actinomycetemcomitans is an important pathogen related to aggressively progressive periodontal breakdown in adolescents and adults. The species can be divided into six serotypes (a–f) according to their surface carbohydrate antigens. Recently, a new serotype g of A. actinomycetemcomitans was proposed. The aim of the present study was to sequence the gene cluster associated with the biosynthesis of the serotype g-specific polysaccharide antigen and develop serotype-specific primers for PCR assay to identify serotype g strains of A. actinomycetemcomitans. The serotype-specific polysaccharide (SSPS) gene cluster of the NUM-Aa 4039 strain contained 21 genes in 21,842-bp nucleotides. The similarity of the SSPS gene cluster sequence was 96.7 % compared with that of the serotype e strain. Seventeen serotype g genes showed more than 90 % homology both in nucleotide and amino acids to the serotype e strain. Three additional genes with 1,579 bp in NUM-Aa 4039 were inserted into the corresponding ORF13 of the serotype e strain. The serotype g-specific primers were designed from the insertion region of NUM-Aa 4039. Serotypes of the a–f strains were not amplified by serotype-specific g primers; only NUM-Aa 4039 showed an amplicon band. The NUM-Aa 4039 strain was three genes in the SSPS gene cluster different from those of serotype e strain. The specific primers derived from these different regions are useful for identification and distribution of serotype g strain among A. actinomycetemcomitans from clinical samples.  相似文献   

5.
The Inc-W group plasmid Sa or its derivative MiniSa were introduced into two strains ofAgrobacterium tumefaciens with Ti plasmids, one strain ofA. tumefaciens with the Ri plasmid and oneA. rhizogenes strain with the Ri plasmid. The effect was similar in allAgrobacterium strains. The pSa suppressed fully the virulence ofAgrobacterium strains (i.e. their ability to induce tumor growths - crown galls or hairj7 roots) inKalanchoe plants and carrot root slices. The MiniSa plasmid caused only a slight decrease of the frequency and size of tumor growths induced. The mechanism of suppression of virulence by the Sa plasmid inAgrobacterium tumefaciens andAgrobacterium rhizogenes seems to be similar.  相似文献   

6.
7.
A Gram-positive, moderately halotolerant, rod-shaped, spore forming bacterium, designated strain FJAT-14515T was isolated from a soil sample in Cihu area, Taoyuan County, Taiwan. The strain grew at 10–35 °C (optimum at 30 °C), pH 5.7–9.0 (optimum at pH 7.0) and at salinities of 0–5 % (w/v) NaCl (optimum at 1 % w/v). The diagnostic diamino acid of the peptidoglycan of the isolated strain was meso-diaminopimelic acid and major respiratory isoprenoid quinone was MK-7. Major cellular fatty acids were anteiso-C15:0 (40.6 %), iso-C15:0 (20.7 %) and the DNA G+C content of strain FJAT-14515T was 37.1 mol %. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-14515T belongs to the genus Bacillus, and was most closely related to the reference strains of Bacillus muralis DSM 16288T (97.6 %) and Bacillus simplex DSM 1321T (97.5 %). Levels of DNA–DNA relatedness between strain FJAT-14515T and the reference strains of B. muralis DSM 16288T and B. simplex DSM 1321T were 27.9 % ± 3.32 and 44.1 % ± 0.57, respectively. Therefore, on the basis of phenotypic, chemotaxonomic and genotypic properties, strain FJAT-14515T represents a novel species of the genus Bacillus, for which the name Bacillus cihuensis sp. nov. is proposed. The type strain is FJAT-14515T (=DSM 25969T = CGMCC 1.12697T).  相似文献   

8.
In this study, a central venous catheter (CVC)—associated infection model was established in rats to investigate and evaluate the effect of biofilms on the virulence of the pathogens. Twenty-four adult SD rats were randomly divided into biofilm positive (BF+) and biofilm negative (BF?) groups to be challenged with strains of S.epidermidis. Serum levels of inflammatory cytokines were measured and the infection rate and counts of bacteria cells were studied. Compared to rats of BF? group, the serum level of TNF and IL-6 significantly increased in rats of BF+ group (P < 0.01) and the level of IL-10 and IFN-γ significantly decreased (P < 0.01), striking the balance of pro-inflammatory/anti-inflammatory cytokines. The infection rate and bacterial counts in tissues and blood of rats of BF + group were significantly higher than those of rats of BF? group (P < 0.05).Inflammatory cell infiltration in vital organs (heart, lung, liver and kidneys) was more significant in rats of BF+ group than that of rats of BF- group. CVC-associated infection model can be successfully reproduced in rats by injecting 5 × 106 CFU of S.epidermidis. Biofilm formation can significantly enhance the virulence of the bacteria, leading to uncontrolled infection. The serum level of inflammatory cytokines, infection rate and the extent of inflammatory cell infiltration are important markers for evaluating the virulence of biofilm.  相似文献   

9.
Two Gram-negative, non-motile, short-rod-shaped bacterial isolates, designated 110399T and 110248, were isolated from an oil-polluted saline soil in Shengli Oilfield, Eastern China. The two strains shared 99.9 % 16S rRNA gene sequence similarity with the DNA–DNA relatedness value being 80.0 %. They were both capable to grow at 20–40 °C, pH 7–9, and 1–9 % (w/v) NaCl with the optimum growth happened at 30 °C, pH 8, and 2–6 % (w/v) NaCl. The phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains were members of Nitratireductor and most closely related to Nitratireductor pacificus pht-3BT and N. basaltis J3T with the 16S rRNA gene sequence similarities being 97.1 and 97.0 %. The DNA–DNA relatedness between the novel strains and two type strains were below 27 ± 7 %. The strains 110399T and 110248 also differed from N. pacificus and N. basaltis in nitrate reduction, salt tolerance, enzyme activities, and utilization of carbon sources. The major cellular fatty acids of strain 110399T were C19:0ω8c cyclo (10.5 %) and Summed Feature 8 (C18:1ω7c and/or C18:1ω6c, 41.5 %) which are typical in the genus Nitratireductor. The predominant ubiquinone was Q-10. The genome DNA G+C content of strain 110399T and 110248 was 61.1 and 61.7 mol%. On the basis of genetic, phenotypic, and chemotaxonomic analyses, strains 110399T and 110248 represent a novel species within the genus Nitratireductor, for which the name Nitratireductor shengliensis sp. nov. is proposed. The type strain is 110399T (=CGMCC 1.12519T = LMG 27405T).  相似文献   

10.
11.
A Gram-stain negative, aerobic, non-motile and coccoid, ovoid or rod-shaped bacterial strain, J-TF4T, which was isolated from a tidal flat in the South Sea of South Korea, was characterized taxonomically. Strain J-TF4T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in presence of 2.0–3.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain J-TF4T fell within the clade comprising the type strains of Loktanella species, clustering with the type strains of Loktanella cinnabarina, Loktanella hongkongensis, Loktanella soesokkakensis, Loktanella pyoseonensis and ‘Loktanella variabilis’ showing sequence similarity values of 97.2–98.4 %. The strain exhibited 16S rRNA gene sequence similarity values of 94.1–95.4 % to the type strains of the other Loktanella species. Strain J-TF4T was found to have Q-10 as the predominant ubiquinone and C18:1 ω7c as the major fatty acid. The major polar lipids of strain J-TF4T were identified as phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and an unidentified aminolipid. The DNA G+C content of strain J-TF4T was determined to be 67.9 mol% and its mean DNA–DNA relatedness values with the type strains of five phylogenetically related Loktanella species were 17.7–23.3 %. Differential phenotypic properties, together with the phylogenetic and genetic data, demonstrate that strain J-TF4T is separated from other Loktanella species. On the basis of the data presented, strain J-TF4T is considered to represent a novel species of the genus Loktanella, for which the name Loktanella aestuariicola sp. nov. is proposed. The type strain is J-TF4T (=KCTC 42135T=NBRC 110408T).  相似文献   

12.
A Gram-stain-negative, aerobic, non-motile and rod-shaped or ovoid bacterial strain, GJSW-22T, which was isolated from seawater at Geoje island in South Korea, was characterized taxonomically. Strain GJSW-22T was observed to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain GJSW-22T grouped with the type strains of Thalassobius species, forming a stable cluster with the type strain of Thalassobius aestuarii (bootstrap value of 83.2 %). Strain GJSW-22T exhibited the highest 16S rRNA gene sequence similarity value (98.0 %) to the type strain of T. aestuarii. It exhibited 16S rRNA gene sequence similarity values of 95.6–96.1 % to the type strains of the other Thalassobius species. Strain GJSW-22T was found to contain Q-10 as the predominant ubiquinone and C18:1 ω7c and 11-methyl C18:1 ω7c as the major fatty acids. The major polar lipids of strain GJSW-22T were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The DNA G + C content of strain GJSW-22T is 60.3 mol % and its mean DNA–DNA relatedness value with the type strain of T. aestuarii was 23 %. Differential phenotypic properties, together with the phylogenetic and chemotaxonomic data, confirmed that strain GJSW-22T is distinct from other Thalassobius species. On the basis of the data presented, strain GJSW-22T is considered to represent a novel species of the genus Thalassobius, for which the name Thalassobius aquaeponti sp. nov. is proposed. The type strain is GJSW-22T (=KCTC 42115T = NBRC 110378T).  相似文献   

13.
Stable lines of hairy roots were established from leaf explants of Bacopa monnieri using different strains (A4, R1000, SA79, MTCC 532 and MTCC 2364) of Agrobacterium rhizogenes. The efficiency of hairy roots induction of these strains varied significantly and the maximum transformation frequency (75 %) was observed in case of strain SA79 using leaf explants followed by internode (55 %) in the presence of acetosyringone. Different parameters such as cell density of Agrobacterium suspension, co-cultivation period and infection time influenced the root induction frequency. Maximum frequency of root induction was obtained with bacterial density of 0.6 OD600, 2 days of co-cultivation period and 10 min of infection time. Integration of T-DNA in the genome of hairy roots was confirmed by PCR amplification of rolB gene. Elimination of Agrobacterium from the established root cultures was ascertained by amplifying the DNA fragment specific to 16S rDNA and virD gene. All lines of hairy roots except strain A4 induced showed higher growth rate and accumulated higher levels of ‘bacoside A’ than the untransformed roots. Maximum biomass accumulation (6.8 g l?1) and ‘bacoside A’ content (10.02 mg g?1 DW) were recorded in case of the hairy root line induced by strain MTCC 2364.  相似文献   

14.
A Gram-negative, aerobic, non-flagellated and rod-shaped bacterial strain able to move by gliding, designated TYO-10T, was isolated from an oyster collected at Tongyoung on the South Sea, South Korea. Strain TYO-10T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain TYO-10T joined the cluster comprising the type strains of Mariniflexile species. Strain TYO-10T exhibited 16S rRNA gene sequence similarity values of 95.4–95.7 % to the type strains of Mariniflexile species and of less than 95.4 % to the type strains of other recognized species. Strain TYO-10T was found to contain MK-6 as the predominant menaquinone and iso-C15:0, iso-C15:1 G, anteiso-C15:0, iso-C17:0 3-OH and iso-C15:0 3-OH as the major fatty acids. The major polar lipids of strain TYO-10T were identified as phosphatidylethanolamine and an unidentified lipid, which is similar to those of the type strains of Mariniflexile species, but different from those of other phylogenetically related species. The DNA G+C content of strain TYO-10T was determined to be 35.9 mol%. The differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain TYO-10T is separated from other Mariniflexile species. On the basis of the data presented, strain TYO-10T is considered to represent a novel species of the genus Mariniflexile, for which the name Mariniflexile ostreae sp. nov. is proposed. The type strain is TYO-10T (= KCTC 42113T = CECT 8622T).  相似文献   

15.
The gene encoding an outer membrane lipoprotein (OmlA) of Actinobacillus pleuropneumoniae strain WF83 (serotype 7 reference strain), designated omlA7, was sequenced. The amino acid sequence of OmlA7 showed 64.5 and 71.6% identity to that of OmlA from serotypes 1 (OmlA1) and 5 (OmlA5), respectively. The first 134 amino acids of OmlA7 were identical to those of OmlA5. A Southern blot analysis revealed the presence of a gene highly homologous to the omlA7 in the reference strains of serotypes 3, 4, 6, and 7. A Western blot analysis using a specific antiserum against a recombinant OmlA7 detected expression of the homologous proteins in the serotypes 4, 6, and 7 reference strains and a serotype 3 field strain, but not in a serotype 3 reference strain. The data demonstrate the third antigenically distinct OmlA is expressed in A. pleuropneumoniae.  相似文献   

16.
A Gram-stain negative, aerobic, motile and rod-shaped bacterial strain, designated J-MY2T, was isolated from a tidal flat sediment of the South Sea, South Korea. Strain J-MY2T was found to grow optimally at 30 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences revealed that strain J-MY2T forms a cluster with the type strains of Simiduia species. Strain J-MY2T exhibited 16S rRNA gene sequence similarity values of 97.62–98.77 % to the type strains of four Simiduia species and of <92.95 % sequence similarity to the type strains of the other recognized species. Strain J-MY2T was found to contain Q-8 as the predominant ubiquinone and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C16:0, C18:1 ω7c and C17:1 ω8c as the major fatty acids. The major polar lipids of strain J-MY2T were identified as phosphatidylethanolamine, phosphatidylglycerol, three unidentified glycolipids and one unidentified lipid. The DNA G+C content of strain J-MY2T was determined to be 54.8 mol% and its mean DNA–DNA relatedness values with the type strains of the four Simiduia species were in the range 21–34 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain J-MY2T is separated from other Simiduia species. On the basis of the data presented, strain J-MY2T is considered to represent a novel species of the genus Simiduia, for which the name Simiduia aestuariiviva sp. nov. is proposed. The type strain is J-MY2T ( = KCTC 42073T = CECT 8571T).  相似文献   

17.
Biosurfactants increasingly gain attention due to the manifold of possible applications and production on the basis of renewable resources. Owing to its various characteristics, Surfactin is one of the most studied biosurfactants. Since its discovery, several Surfactin producers have been identified, but their capacity to produce Surfactin has not been evaluated in a comparison. Six different Bacillus strains were analyzed regarding their ability to produce Surfactin in model fermentations with integrated foam fractionation, for in situ product enrichment and removal. Three of the investigated strains are commonly used in Surfactin production (ATCC 21332, DSM 3256, DSM 3258), whereas two Bacillus strains are described for the first time (DSM 1090, LM43a50°C) as Surfactin producers. Additionally, the Bacillus subtilis type strain DSM 10T was included in the evaluation. Interestingly, all strains, except DSM 3256, featured high values for Surfactin recovered from foam in comparison to other studies, ranging between 0.4 and 1.05 g. The fermentation process was characterized by calculating procedural parameters like substrate yield Y X/S, product yield Y P/X, specific growth rate μ, specific productivity q Surfactin, volumetric productivity q Surfactin, Surfactin and bacterial enrichment as well as Surfactin recovery. The strains differ most in specific and volumetric productivity; nevertheless, it is evident that it is not possible to name a Bacillus strain that is the most appropriate for the production of Surfactin under these conditions. In contrast, it becomes apparent that the choice of a specific strain should depend on the applied fermentation conditions.  相似文献   

18.
Group B protective surface protein (BPS) is expressed on the cell surface of some group B streptococcal (GBS) (Streptococcus agalactiae) strains and adds to the identification by capsular polysaccharide (CPS), and c or R proteins. We investigated the prevalence of BPS among GBS clinical isolates (303 invasive, 4122 colonizing) collected over 11 years in four American cities. Hot HCl cell extracts were tested by immunoprecipitation in agarose with rabbit antisera to BPS; the alpha (α) and beta (β) components of c protein; R1, R3, and R4 species of R protein; and CPS serotypes Ia–VIII. BPS was found in 155 isolates (seven invasive, 148 colonizing). Of these, 87 were Ia, 37 II, 20 V; none were III. BPS was expressed usually with another protein: a species of R by 87 or a component of c by 39. The predominant CPS/protein profiles with BPS were Ia/R1,BPS and II/c(α + β),BPS. Thus, along with CPS serotype and other surface proteins, BPS can be a valuable marker for precise strain characterization of unique GBS clinical isolates with complex surface protein profiles.  相似文献   

19.
20.
A Gram-negative bacterial strain, designated WB1T, was isolated from a domestic refrigerator in Guangzhou, PR China. Cells of strain WB1T were oxidase-negative, catalase-positive, strictly aerobic, non-spore-forming and non-motile coccobacilli with peritrichous fimbriae-like structures. The strain was able to grow at 10–40 °C with optimum growth at 28–30 °C, pH 6.0–8.0 (optimum, pH 7.0) and 0–6 % NaCl (w/v, optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and rpoB gene sequences revealed that strain WB1T belonged to the genus Acinetobacter and was most closely related to A. indicus DSM 25388T (97.2 % 16S rRNA gene sequence similarity) and A. radioresistens NBRC 102413T (96.8 %). The DNA G + C content of strain WB1T was 46.74 ± 0.04 mol % and the major fatty acids comprised summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω9c, C16:0 and C12:0. The predominant respiratory quinone was identified as Q-9 and the polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified phospholipid. Phenotypic, phylogenetic and chemotaxonomic data, including low DNA–DNA relatedness with closely related type strains, supported that strain WB1T represents a distinct novel species in the genus Acinetobacter, for which the name Acinetobacter refrigeratorensis sp. nov. was proposed. The type strain is WB1T (=GIMCC 1.663T = CCTCC AB 2014197T = KCTC 42011T).  相似文献   

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