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  • 1
    Online Resource
    Online Resource
    American Society for Microbiology ; 2007
    In:  Journal of Bacteriology Vol. 189, No. 22 ( 2007-11-15), p. 7977-7982
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 189, No. 22 ( 2007-11-15), p. 7977-7982
    Abstract: Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia and a major factor in the porcine respiratory disease complex. A clear understanding of the mechanisms of pathogenesis does not exist, although it is clear that M. hyopneumoniae adheres to porcine ciliated epithelium by action of a protein called P97. Previous studies have shown variation in the gene encoding the P97 cilium adhesin in different strains of M. hyopneumoniae , but the extent of genetic variation among field strains across the genome is not known. Since M. hyopneumoniae is a worldwide problem, it is reasonable to expect that a wide range of genetic variability may exist given all of the different breeds and housing conditions. This variation may impact the overall virulence of a single strain. Using microarray technology, this study examined the potential variation of 14 field strains compared to strain 232, on which the array was based. Genomic DNA was obtained, amplified with TempliPhi, and labeled indirectly with Alexa dyes. After genomic hybridization, the arrays were scanned and data were analyzed using a linear statistical model. The results indicated that genetic variation could be detected in all 14 field strains but across different loci, suggesting that variation occurs throughout the genome. Fifty-nine percent of the variable loci were hypothetical genes. Twenty-two percent of the lipoprotein genes showed variation in at least one field strain. A permutation test identified a location in the M. hyopneumoniae genome where there is spatial clustering of variability between the field strains and strain 232.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2007
    detail.hit.zdb_id: 1481988-0
    SSG: 12
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  • 2
    Online Resource
    Online Resource
    American Society for Microbiology ; 2008
    In:  Journal of Clinical Microbiology Vol. 46, No. 8 ( 2008-08), p. 2491-2498
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 46, No. 8 ( 2008-08), p. 2491-2498
    Abstract: Mycoplasma hyopneumoniae is an important cause of pneumonia in pigs around the world, but confirming its presence in (or absence from) pigs can be difficult. Culture for diagnosis is impractical, and seroconversion is often delayed after natural infection, limiting the use of serology. Numerous PCR assays for the detection of M . hyopneumoniae have been developed, targeting several different genes. Recently, genetic diversity among strains of M . hyopneumoniae was demonstrated. The effect of this diversity on the accuracy and sensitivity of the M . hyopneumoniae PCR assays could result in false-negative results in current PCR tests. In this study, a panel of isolates of M . hyopneumoniae , M. flocculare , M. hyorhinis , and M. hyosynoviae were tested with a number of M . hyopneumoniae -specific PCR assays. Some M . hyopneumoniae PCR assays tested did not detect all isolates of M . hyopneumoniae . To increase the efficiency of PCR testing, two new real-time PCR assays that are specific and capable of detecting all of the M . hyopneumoniae isolates used in this study were developed.
    Type of Medium: Online Resource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2008
    detail.hit.zdb_id: 1498353-9
    SSG: 12
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  • 3
    In: Rangeland Ecology & Management, Elsevier BV, Vol. 77 ( 2021-07), p. 126-135
    Type of Medium: Online Resource
    ISSN: 1550-7424
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2021
    detail.hit.zdb_id: 2180183-6
    SSG: 21
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  • 4
    Online Resource
    Online Resource
    American Society for Microbiology ; 2006
    In:  Infection and Immunity Vol. 74, No. 1 ( 2006-01), p. 160-166
    In: Infection and Immunity, American Society for Microbiology, Vol. 74, No. 1 ( 2006-01), p. 160-166
    Abstract: Bacterial pathogens undergo stress during host colonization and disease processes. These stresses result in changes in gene expression to compensate for potentially lethal environments developed in the host during disease. Mycoplasma hyopneumoniae colonizes the swine epithelium and causes a pneumonia that predisposes the host to enhanced disease from other pathogens. How M. hyopneumoniae responds to changing environments in the respiratory tract during disease progression is not known. In fact, little is known concerning the capabilities of mycoplasmas to respond to changing growth environments. With limited genes, mycoplasmas are thought to possess only a few mechanisms for gene regulation. A microarray consisting of 632 of the 698 open reading frames of M. hyopneumoniae was constructed and used to study gene expression differences during a temperature shift from 37°C to 42°C, a temperature swing that might be encountered during disease. To enhance sensitivity, a unique hexamer primer set was employed for generating cDNA from only mRNA species. Our analysis identified 91 genes that had significant transcriptional differences in response to heat shock conditions ( P 〈 0.01) with an estimated false-discovery rate of 4 percent. Thirty-three genes had a change threshold of 1.5-fold or greater. Many of the heat shock proteins previously characterized in other bacteria were identified as significant in this study as well. A proportion of the identified genes (54 of 91) currently have no assigned function.
    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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  • 5
    Online Resource
    Online Resource
    American Society for Microbiology ; 2008
    In:  Infection and Immunity Vol. 76, No. 2 ( 2008-02), p. 658-663
    In: Infection and Immunity, American Society for Microbiology, Vol. 76, No. 2 ( 2008-02), p. 658-663
    Abstract: Mycoplasma hyopneumoniae causes swine pneumonia and contributes significantly to the porcine respiratory disease complex. The mechanisms of pathogenesis are difficult to address, since there is a lack of genetic tools, but microarrays are available and can be used to study transcriptional changes that occur during disease as a way to identify important virulence-related genes. Mycoplasmas were collected from bronchial alveolar lavage samples and compared to broth-grown cells using microarrays. Bronchial alveolar lavage was performed on pigs 28 days postinfection, and mycoplasmas were isolated by differential centrifugation. Mycoplasma RNA-enriched preparations were then obtained from total RNA by subtracting eucaryotic ribosomal and messenger RNAs. Labeled cDNAs were generated with mycoplasma open reading frame-specific primers. Nine biological replicates were analyzed. During lung infection, our analysis indicated that 79 M. hyopneumoniae genes were differentially expressed ( P 〈 0.01), at a false-discovery rate of 〈 2.7%. Of the down-regulated genes, 28 of 46 (61%) lacked an assigned function, in comparison to 21 of 33 (63%) of up-regulated genes. Four down-regulated genes and two up-regulated genes encoded putative lipoproteins. secA (mhp295) ( P = 0.003) and two glycerol transport permease genes ( potA [mhp380; P = 0.006] and ugpA [mhp381; P = 0.003]) were up-regulated in vivo. Elongation factor EF-G ( fusA [mhp083]) ( P = 0.002), RNA polymerase beta chain ( rpoC [mhp635]) ( P = 0.003), adenylate kinase ( adk [mhp208]) ( P = 0.001), prolyl aminoacyl tRNA synthetase ( proS [mhp397]) ( P = 0.009), and cysteinyl-tRNA synthetase ( cysS [mhp661]) ( P 〈 0.001) were down-regulated in vivo.
    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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  • 6
    Online Resource
    Online Resource
    Microbiology Society ; 2006
    In:  Microbiology Vol. 152, No. 4 ( 2006-04-01), p. 937-944
    In: Microbiology, Microbiology Society, Vol. 152, No. 4 ( 2006-04-01), p. 937-944
    Abstract: Mycoplasma hyopneumoniae , the causative agent of swine enzootic pneumonia and a major component of the porcine respiratory disease complex, continues to confound swine producers despite control programmes worldwide. The disease is chronic and self-limiting, but the host is subject to immunopathological changes that potentiate respiratory disease associated with other pathogens. The response of M. hyopneumoniae to environmental stress is of interest because of its relevance to virulence mechanisms in other bacterial pathogens. One of these stressors, iron deprivation, is a prominent feature of the host innate immune response, and most certainly impacts growth of mycoplasmas in vivo . To study this, microarray technology was applied to the transcriptome analysis of M. hyopneumoniae during iron deprivation. An array consisting of 632 of the 698 ORFs in the genome was used to compare the mRNA isolated from organisms grown under normal laboratory conditions with that from organisms subjected to iron deprivation with the chelator 2,2′-dipyridyl. This analysis identified 27 genes that were either up- or down-regulated in response to low-iron growth conditions ( P 〈 0·01), with an estimated false discovery rate below 10 %. These included genes encoding transport proteins, enzymes involved in energy metabolism, and components of the translation process. Ten of the 27 identified genes had no assigned function. These studies indicate that M. hyopneumoniae can respond to changes in environmental conditions, but the mechanism employed remains unknown.
    Type of Medium: Online Resource
    ISSN: 1350-0872 , 1465-2080
    Language: English
    Publisher: Microbiology Society
    Publication Date: 2006
    detail.hit.zdb_id: 2008736-6
    SSG: 12
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  • 7
    Online Resource
    Online Resource
    Microbiology Society ; 2007
    In:  Microbiology Vol. 153, No. 11 ( 2007-11-01), p. 3785-3790
    In: Microbiology, Microbiology Society, Vol. 153, No. 11 ( 2007-11-01), p. 3785-3790
    Type of Medium: Online Resource
    ISSN: 1350-0872 , 1465-2080
    Language: English
    Publisher: Microbiology Society
    Publication Date: 2007
    detail.hit.zdb_id: 2008736-6
    SSG: 12
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  • 8
    Online Resource
    Online Resource
    American Society for Microbiology ; 2013
    In:  Infection and Immunity Vol. 81, No. 11 ( 2013-11), p. 4053-4062
    In: Infection and Immunity, American Society for Microbiology, Vol. 81, No. 11 ( 2013-11), p. 4053-4062
    Abstract: The autoinducer-2 (AI-2) quorum-sensing system has been linked to diverse phenotypes and regulatory changes in pathogenic bacteria. In the present study, we performed a molecular and biochemical characterization of the AI-2 system in Yersinia pestis , the causative agent of plague. In strain CO92, the AI-2 signal is produced in a luxS -dependent manner, reaching maximal levels of 2.5 μM in the late logarithmic growth phase, and both wild-type and pigmentation ( pgm ) mutant strains made equivalent levels of AI-2. Strain CO92 possesses a chromosomal lsr locus encoding factors involved in the binding and import of AI-2, and confirming this assignment, an lsr deletion mutant increased extracellular pools of AI-2. To assess the functional role of AI-2 sensing in Y. pestis , microarray studies were conducted by comparing Δ pgm strain R88 to a Δ pgm Δ luxS mutant or a quorum-sensing-null Δ pgm Δ ypeIR Δ yspIR Δ luxS mutant at 37°C. Our data suggest that AI-2 quorum sensing is associated with metabolic activities and oxidative stress genes that may help Y. pestis survive at the host temperature. This was confirmed by observing that the luxS mutant was more sensitive to killing by hydrogen peroxide, suggesting a potential requirement for AI-2 in evasion of oxidative damage. We also show that a large number of membrane protein genes are controlled by LuxS, suggesting a role for quorum sensing in membrane modeling. Altogether, this study provides the first global analysis of AI-2 signaling in Y. pestis and identifies potential roles for the system in controlling genes important to disease.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2013
    detail.hit.zdb_id: 1483247-1
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  • 9
    In: Radiation Research, Radiation Research Society, Vol. 174, No. 3 ( 2010-09), p. 290-296
    Type of Medium: Online Resource
    ISSN: 0033-7587 , 1938-5404
    RVK:
    Language: English
    Publisher: Radiation Research Society
    Publication Date: 2010
    detail.hit.zdb_id: 2135113-2
    detail.hit.zdb_id: 80322-4
    SSG: 11
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  • 10
    Online Resource
    Online Resource
    Mary Ann Liebert Inc ; 2008
    In:  Foodborne Pathogens and Disease Vol. 5, No. 4 ( 2008-08), p. 517-529
    In: Foodborne Pathogens and Disease, Mary Ann Liebert Inc, Vol. 5, No. 4 ( 2008-08), p. 517-529
    Type of Medium: Online Resource
    ISSN: 1535-3141 , 1556-7125
    Language: English
    Publisher: Mary Ann Liebert Inc
    Publication Date: 2008
    detail.hit.zdb_id: 2155983-1
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