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  • 1
    In: Infection and Immunity, American Society for Microbiology, Vol. 74, No. 11 ( 2006-11), p. 6046-6056
    Abstract: Mycobacterium avium subsp. paratuberculosis is the causative agent of Johne's disease in animals and has been hypothesized to be associated with Crohn's disease in humans. Recently, M. avium subsp. paratuberculosis isolates recovered from Crohn's disease patients were shown to have limited diversity, implying the existence of human disease-associated genotypes and strain sharing with animals (A. H. Ghadiali et al., J. Clin. Microbiol. 42: 5345-5348, 2004). To explore whether these genotypic differences or similarities among human and animal isolates translated to functionally significant attributes such as variance in host preference and/or difference in magnitude of infections, we performed a global scale analysis of M. avium subsp. paratuberculosis isolates that were representative of different genotypes and host species using DNA microarrays. Genome-wide characterization of the transcriptional changes was carried out using a human monocytic cell line (THP-1 cells) in response to different genotypes of M. avium subsp. paratuberculosis isolates recovered from various hosts. We identified several differentially expressed genes during early intracellular infection, including those involved in common canonical pathways such as NF-κB, interleukin-6 (IL-6), mitogen-activated protein kinase/extracellular signal-regulated kinase, and Jun N-terminal protein kinase signaling, as well as genes involved in T helper type 1 (Th1) responses (such as CCL5 ligand) and those that encode several proinflammatory cytokines and chemokine receptors. The cattle and human isolates of M. avium subsp. paratuberculosis , regardless of their short sequence repeat (SSR) genotype, induced similar global gene expression patterns in THP-1 cells. They differentially regulated genes necessary for cell survival without causing major alterations in proinflammatory genes. In contrast, the sheep isolates representing diverse SSR genotypes closely resembled the global gene expression pattern of an M. avium subsp. avium isolate, and they significantly up-regulated proinflammatory genes related to IL-6, T-cell receptor, B-cell receptor, and death receptor signaling within THP-1 cells. Additionally, we demonstrated consistency among infecting genotypes of M. avium subsp. paratuberculosis isolated from diverse hosts [cattle ( n = 2), human ( n = 3), sheep ( n = 2), and bison ( n = 1)] in quantitative reverse transcription-PCR analysis of seven differentially expressed genes. While the levels of expression induced by the bison isolate were different compared with cattle or human isolates, they followed the common anti-inflammatory, antiapoptotic trend. Our data suggest that the macrophage responses to M. avium subsp. paratuberculosis isolates from cattle and human sources, regardless of genotype, follow a common theme of anti-inflammatory responses, an attribute likely associated with successful infection and persistence. However, these expression patterns differ significantly from those in THP-1 cells infected with sheep isolates of M. avium subsp. paratuberculosis or the M. avium subsp. avium isolate. These data provide a transcriptional basis for a variety of pathophysiological changes observed during early stages of infection by different strains of M. avium subsp. paratuberculosis , a first step in understanding trait-allele association in this economically important disease.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2006
    detail.hit.zdb_id: 1483247-1
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  • 2
    Online Resource
    Online Resource
    American Society for Microbiology ; 2002
    In:  Journal of Bacteriology Vol. 184, No. 4 ( 2002-02-15), p. 1095-1101
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 184, No. 4 ( 2002-02-15), p. 1095-1101
    Abstract: Subgenomic DNA microarrays were employed to evaluate the expression of the accessory gene regulator ( agr locus) as well as multiple virulence-associated genes in Staphylococcus aureus . Gene expression was examined during growth of S. aureus in vitro in standard laboratory medium and rabbit serum and in vivo in subcutaneous chambers implanted in either nonimmune rabbits or rabbits immunized with staphylococcal enterotoxin B. Expression of RNAIII, the effector molecule of the agr locus, was dramatically repressed in serum and in vivo, despite the increased expression of secreted virulence factors sufficient to cause toxic shock syndrome (TSS) in the animals. Statistical analysis and clustering of virulence genes based on their expression profiles in the various experimental conditions demonstrated no positive correlation between the expression of agr and any staphylococcal virulence factors examined. Disruption of the agr locus had only a minimal effect on the expression in vivo of the virulence factors examined. An effect of immunization on the expression of agr and virulence factors was also observed. These results suggest that agr activation is not necessary for development of staphylococcal TSS and that regulatory circuits responding to the in vivo environment override agr activity.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2002
    detail.hit.zdb_id: 1481988-0
    SSG: 12
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  • 3
    Online Resource
    Online Resource
    American Society for Microbiology ; 2004
    In:  Journal of Clinical Microbiology Vol. 42, No. 1 ( 2004-01), p. 106-114
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 42, No. 1 ( 2004-01), p. 106-114
    Abstract: The development of immunoassays specific for the diagnosis of Johne's disease in cattle requires antigens specific to Mycobacterium avium subsp. paratuberculosis . However, because of genetic similarity to other mycobacteria comprising the M. avium complex, no such antigens have been found. Through a comparative genomics approach, 21 potential coding sequences of M. avium subsp. paratuberculosis that are not represented in any other mycobacterial species tested ( n = 9) were previously identified (J. P. Bannantine, E. Baechler, Q. Zhang, L. Li, and V. Kapur, J. Clin. Microbiol. 40: 1303-1310, 2002). Here we describe the cloning, heterologous expression, and antigenic analysis of these M. avium subsp. paratuberculosis -specific sequences in Escherichia coli . Nucleotide sequences representing each unique predicted coding region were amplified and cloned into two different E. coli expression vectors encoding polyhistidine or maltose binding protein (MBP) affinity purification tags. All 21 of the MBP fusion proteins were successfully purified under denaturing conditions and were evaluated in immunoblotting studies with sera from rabbits and mice immunized with M. avium subsp. paratuberculosis . These studies showed that 5 of the 21 gene products are produced by M. avium subsp. paratuberculosis and are antigenic. Immunoblot analysis with a panel of sera from 9 healthy cattle and 10 cattle with clinical disease shows that the same five M. avium subsp. paratuberculosis proteins are also detected within the context of infection. Collectively, these studies have used a genomic approach to identify novel M. avium subsp. paratuberculosis antigens that are not present in any other mycobacteria. These findings may have a major impact on improved diagnostics for Johne's disease.
    Type of Medium: Online Resource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2004
    detail.hit.zdb_id: 1498353-9
    SSG: 12
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  • 4
    Online Resource
    Online Resource
    Proceedings of the National Academy of Sciences ; 2001
    In:  Proceedings of the National Academy of Sciences Vol. 98, No. 6 ( 2001-03-13), p. 3460-3465
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 98, No. 6 ( 2001-03-13), p. 3460-3465
    Abstract: We present here the complete genome sequence of a common avian clone of Pasteurella multocida , Pm70. The genome of Pm70 is a single circular chromosome 2,257,487 base pairs in length and contains 2,014 predicted coding regions, 6 ribosomal RNA operons, and 57 tRNAs. Genome-scale evolutionary analyses based on pairwise comparisons of 1,197 orthologous sequences between P. multocida , Haemophilus influenzae , and Escherichia coli suggest that P. multocida and H. influenzae diverged ≈270 million years ago and the γ subdivision of the proteobacteria radiated about 680 million years ago. Two previously undescribed open reading frames, accounting for ≈1% of the genome, encode large proteins with homology to the virulence-associated filamentous hemagglutinin of Bordetella pertussis . Consistent with the critical role of iron in the survival of many microbial pathogens, in silico and whole-genome microarray analyses identified more than 50 Pm70 genes with a potential role in iron acquisition and metabolism. Overall, the complete genomic sequence and preliminary functional analyses provide a foundation for future research into the mechanisms of pathogenesis and host specificity of this important multispecies pathogen.
    Type of Medium: Online Resource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Language: English
    Publisher: Proceedings of the National Academy of Sciences
    Publication Date: 2001
    detail.hit.zdb_id: 209104-5
    detail.hit.zdb_id: 1461794-8
    SSG: 11
    SSG: 12
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  • 5
    Online Resource
    Online Resource
    Elsevier BV ; 2002
    In:  Journal of Biological Chemistry Vol. 277, No. 15 ( 2002-04), p. 13138-13147
    In: Journal of Biological Chemistry, Elsevier BV, Vol. 277, No. 15 ( 2002-04), p. 13138-13147
    Type of Medium: Online Resource
    ISSN: 0021-9258
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2002
    detail.hit.zdb_id: 2141744-1
    detail.hit.zdb_id: 1474604-9
    SSG: 12
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  • 6
    Online Resource
    Online Resource
    American Society for Microbiology ; 2002
    In:  Journal of Bacteriology Vol. 184, No. 23 ( 2002-12), p. 6714-6720
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 184, No. 23 ( 2002-12), p. 6714-6720
    Abstract: Pasteurella multocida was grown in iron-free chemically defined medium supplemented with hemoglobin, transferrin, ferritin, and ferric citrate as iron sources. Whole-genome DNA microarrays were used to monitor global gene expression over seven time points after the addition of the defined iron source to the medium. This resulted in a set of data containing over 338,000 gene expression observations. On average, 12% of P. multocida genes were differentially expressed under any single condition. A majority of these genes encoded P. multocida proteins that were involved in either transport and binding or were annotated as hypothetical proteins. Several trends are evident when the data from different iron sources are compared. In general, only two genes ( ptsN and sapD ) were expressed at elevated levels under all of the conditions tested. The results also show that genes with increased expression in the presence of hemoglobin did not respond to transferrin or ferritin as an iron source. Correspondingly, genes with increased expression in the transferrin and ferritin experiments were expressed at reduced levels when hemoglobin was supplied as the sole iron source. Finally, the data show that genes that were most responsive to the presence of ferric citrate did not follow a trend similar to that of the other iron sources, suggesting that different pathways respond to inorganic or organic sources of iron in P. multocida . Taken together, our results demonstrate that unique subsets of P. multocida genes are expressed in response to different iron sources and that many of these genes have yet to be functionally characterized.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2002
    detail.hit.zdb_id: 1481988-0
    SSG: 12
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  • 7
    Online Resource
    Online Resource
    American Society for Microbiology ; 2001
    In:  Infection and Immunity Vol. 69, No. 6 ( 2001-06), p. 4109-4115
    In: Infection and Immunity, American Society for Microbiology, Vol. 69, No. 6 ( 2001-06), p. 4109-4115
    Abstract: Pasteurella multocida is the causative agent of a wide range of diseases in avian and mammalian hosts. Gene expression in response to low iron conditions was analyzed in P. multocida using whole-genome microarrays. The analysis shows that the expression of genes involved in energy metabolism and electron transport generally decreased 2.1- to 6-fold while that of genes used for iron binding and transport increased 2.1- to 7.7-fold in P. multocida during the first 2 h of growth under iron-limiting conditions compared with controls. Notably, 27% of the genes with significantly altered expression had no known function, illustrating the limitations of using publicly available databases to identify genes involved in microbial metabolism and pathogenesis. Taken together, the results of our investigations demonstrate the utility of whole-genome microarray analyses for the identification of genes with altered expression profiles during varying growth conditions and provide a framework for the detailed analysis of the molecular mechanisms of iron acquisition and metabolism in P. multocida and other gram-negative bacteria.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2001
    detail.hit.zdb_id: 1483247-1
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  • 8
    In: Infection and Immunity, American Society for Microbiology, Vol. 76, No. 2 ( 2008-02), p. 739-749
    Abstract: With the genome sequence of Mycobacterium avium subsp. paratuberculosis determined, technologies are now being developed for construction of protein arrays to detect the presence of antibodies against M. avium subsp. paratuberculosis in host serum. The power of this approach is that it enables a direct comparison of M. avium subsp. paratuberculosis proteins to each other in relation to their immunostimulatory capabilities. In this study, 93 recombinant proteins, produced in Escherichia coli , were arrayed and spotted onto nitrocellulose. These proteins include unknown hypothetical proteins and cell surface proteins as well as proteins encoded by large sequence polymorphisms present uniquely in M. avium subsp. paratuberculosis . Also included were previously reported or known M. avium subsp. paratuberculosis antigens to serve as a frame of reference. Sera from healthy control cattle ( n = 3) and cattle infected with either M. avium subsp. avium and Mycobacterium bovis were exposed to the array to identify nonspecific or cross-reactive epitopes. These data demonstrated a degree of cross-reactivity with the M. avium subsp. avium proteins that was higher than the degree of cross-reactivity with the more distantly related M. bovis proteins. Finally, sera from naturally infected cattle ( n = 3) as well as cattle experimentally infected with M. avium subsp. paratuberculosis ( n = 3) were used to probe the array to identify antigens in the context of Johne's disease. Three membrane proteins were the most strongly detected in all serum samples, and they included an invasion protein, an ABC peptide transport permease, and a putative GTPase protein. This powerful combination of genomic information, molecular tools, and immunological assays has enabled the identification of previously unknown antigens of M. avium subsp. paratuberculosis .
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2008
    detail.hit.zdb_id: 1483247-1
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  • 9
    In: PROTEOMICS, Wiley, Vol. 8, No. 3 ( 2008-02), p. 463-474
    Type of Medium: Online Resource
    ISSN: 1615-9853 , 1615-9861
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2008
    detail.hit.zdb_id: 2037674-1
    SSG: 12
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  • 10
    In: Foodborne Pathogens and Disease, Mary Ann Liebert Inc, Vol. 1, No. 1 ( 2004-03), p. 3-15
    Type of Medium: Online Resource
    ISSN: 1535-3141 , 1556-7125
    Language: English
    Publisher: Mary Ann Liebert Inc
    Publication Date: 2004
    detail.hit.zdb_id: 2155983-1
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