feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Online-Ressource
    Online-Ressource
    American Society for Microbiology ; 1989
    In:  Applied and Environmental Microbiology Vol. 55, No. 2 ( 1989-02), p. 516-519
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 55, No. 2 ( 1989-02), p. 516-519
    Kurzfassung: A cell extract of a polychlorophenol-degrading bacterium, Rhodococcus sp. strain CP-2, isolated from chlorophenol-contaminated soil, was shown to dechlorinate tetrachlorohydroquinone, the first intermediate in pentachlorophenol and 2,3,5,6-tetrachlorophenol degradation. Degradation of tetrachlorohydroquinone was catalyzed by a soluble enzyme(s). The reaction sequence for complete dechlorination involved hydroxylation and three reductive dechlorinations, producing 1,2,4-trihydroxybenzene. All chlorines were thus removed from the polychlorinated compound before ring cleavage.
    Materialart: Online-Ressource
    ISSN: 0099-2240 , 1098-5336
    RVK:
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 1989
    ZDB Id: 223011-2
    ZDB Id: 1478346-0
    SSG: 12
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Online-Ressource
    Online-Ressource
    American Society for Microbiology ; 2003
    In:  Journal of Clinical Microbiology Vol. 41, No. 7 ( 2003-07), p. 3198-3205
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 41, No. 7 ( 2003-07), p. 3198-3205
    Kurzfassung: Swine influenza is an acute respiratory disease caused by type A influenza viruses. Before 1998, swine influenza virus isolates in the United States were mainly of the classical H1N1 lineage. Since then, phylogenetically distinct reassortant H3N2 viruses have been identified as respiratory pathogens in pigs on U.S. farms. The H3N2 viruses presently circulating in the U.S. swine population are triple reassortants containing avian-like (PA and PB2), swine-like (M, NP, and NS), and human-like (HA, NA, and PB1) gene segments. Recent sequence data show that the triple reassortants have acquired at least three distinct H3 molecules from human influenza viruses and thus form three distinct phylogenetic clusters (I to III). In this study we analyzed the antigenic and pathogenic properties of viruses belonging to each of these clusters. Hemagglutination inhibition and neutralization assays that used hyperimmune sera obtained from caesarian-derived, colostrum-deprived pigs revealed that H3N2 cluster I and cluster III viruses share common epitopes, whereas a cluster II virus showed only limited cross-reactivity. H3N2 viruses from each of the three clusters were able to induce clinical signs of disease and associated lesions upon intratracheal inoculation into seronegative pigs. There were, however, differences in the severity of lesions between individual strains even within one antigenic cluster. A correlation between the severity of disease and pig age was observed. These data highlight the increased diversity of swine influenza viruses in the United States and would indicate that surveillance should be intensified to determine the most suitable vaccine components.
    Materialart: Online-Ressource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2003
    ZDB Id: 1498353-9
    SSG: 12
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 42, No. 3 ( 2004-03), p. 1220-1223
    Kurzfassung: Entamoeba histolytica , Giardia lamblia , and Cryptosporidium are three of the most important diarrhea-causing parasitic protozoa. For many years, microscopic examination of stool samples has been considered to be the “gold standard” for diagnosis of E. histolytica , G. lamblia , and C. parvum infections. Recently, more specific and sensitive alternative methods (PCR, enzyme-linked immunosorbent assay, and direct fluorescent-antibody assay) have been introduced for all three of these parasitic infections. However, the incorporation in a routine diagnostic laboratory of these parasite-specific methods for diagnosis of each of the respective infections is time-consuming and increases the costs of a stool examination. Therefore, a multiplex real-time PCR assay was developed for the simultaneous detection of E. histolytica , G. lamblia , and C. parvum in stool samples. The multiplex PCR also included an internal control to determine efficiency of the PCR and detect inhibition in the sample. The assay was performed on species-specific DNA controls and a range of well-defined stool samples, and it achieved 100 percent specificity and sensitivity. The use of this assay in a diagnostic laboratory would provide sensitive and specific diagnosis of the main parasitic diarrheal infections and could improve patient management and infection control.
    Materialart: Online-Ressource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2004
    ZDB Id: 1498353-9
    SSG: 12
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Online-Ressource
    Online-Ressource
    American Society for Microbiology ; 2010
    In:  Journal of Virology Vol. 84, No. 2 ( 2010-01-15), p. 686-694
    In: Journal of Virology, American Society for Microbiology, Vol. 84, No. 2 ( 2010-01-15), p. 686-694
    Kurzfassung: Two novel paramyxoviruses, 81-19252 (Texas81) and 92-7783 (ISU92), isolated from the brains of pigs in the United States in the 1980s and 1990s, were characterized. The complete genome of Texas81 virus was 15,456 nucleotides (nt) in length, that of ISU92 was 15,480 nt, and both genomes consisted of six nonoverlapping genes, predicted to encode nine proteins, with conserved and complementary 3′ leader and 5′ trailer regions and conserved gene starts, gene stops, and trinucleotide intergenic sequences similar to those in paramyxoviruses. The corresponding genes from these two viruses were similar in length, except for the F genes, of which the ISU92 form had an additional 24-nt U-rich 3′ untranslated region. The P genes of swine viruses were predicted to produce V and D mRNAs by RNA editing (one to four G insertions in Texas81 and one to nine G insertions in ISU92) or C mRNA by alternative translation initiation. Sequence-specific features related to virus replication and host-specific amino acid signatures indicated that these viruses originated from bovine parainfluenzavirus 3 (bPIV3). Phylogenetic analysis of individual genes suggested that these viruses are novel members of the genus Respirovirus of the Paramyxovirinae subfamily and may be grouped into two subgenotypes of genotype A of bPIV3. Our comprehensive studies revealed that these swine PIV3 are variants of bPIV3 and were possibly transferred from cattle to pigs but failed to establish an active enzootic state. These two viruses were mildly pathogenic to conventionally reared pigs, and results from a limited enzyme-linked immunosorbent assay-based serosurvey of swine farms in Minnesota and Iowa in 2007 and 2008 were negative.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2010
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Online-Ressource
    Online-Ressource
    American Society for Microbiology ; 2005
    In:  Journal of Virology Vol. 79, No. 12 ( 2005-06-15), p. 7535-7543
    In: Journal of Virology, American Society for Microbiology, Vol. 79, No. 12 ( 2005-06-15), p. 7535-7543
    Kurzfassung: It has been shown previously that the nonstructural protein NS1 of influenza virus is an alpha/beta interferon (IFN-α/β) antagonist, both in vitro and in experimental animal model systems. However, evidence of this function in a natural host has not yet been obtained. Here we investigated the role of the NS1 protein in the virulence of a swine influenza virus (SIV) isolate in pigs by using reverse genetics. The virulent wild-type A/Swine/Texas/4199-2/98 (TX/98) virus and various mutants encoding carboxy-truncated NS1 proteins were rescued. Growth properties of TX/98 viruses with mutated NS1, induction of IFN in tissue culture, and virulence-attenuation in pigs were analyzed and compared to those of the recombinant wild-type TX/98 virus. Our results indicate that deletions in the NS1 protein decrease the ability of the TX/98 virus to prevent IFN-α/β synthesis in pig cells. Moreover, all NS1 mutant viruses were attenuated in pigs, and this correlated with the amount of IFN-α/β induced in vitro. These data suggest that the NS1 protein of SIV is a virulence factor. Due to their attenuation, NS1-mutated swine influenza viruses might have a great potential as live attenuated vaccine candidates against SIV infections of pigs.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2005
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    In: Journal of Virology, American Society for Microbiology, Vol. 91, No. 6 ( 2017-03-15)
    Kurzfassung: In contrast to other available next-generation sequencing platforms, PacBio single-molecule, real-time (SMRT) sequencing has the advantage of generating long reads albeit with a relatively higher error rate in unprocessed data. Using this platform, we longitudinally sampled and sequenced the hepatitis C virus (HCV) envelope genome region (1,680 nucleotides [nt]) from individuals belonging to a cluster of sexually transmitted cases. All five subjects were coinfected with HIV-1 and a closely related strain of HCV genotype 4d. In total, 50 samples were analyzed by using SMRT sequencing. By using 7 passes of circular consensus sequencing, the error rate was reduced to 0.37%, and the median number of sequences was 612 per sample. A further reduction of insertions was achieved by alignment against a sample-specific reference sequence. However, in vitro recombination during PCR amplification could not be excluded. Phylogenetic analysis supported close relationships among HCV sequences from the four male subjects and subsequent transmission from one subject to his female partner. Transmission was characterized by a strong genetic bottleneck. Viral genetic diversity was low during acute infection and increased upon progression to chronicity but subsequently fluctuated during chronic infection, caused by the alternate detection of distinct coexisting lineages. SMRT sequencing combines long reads with sufficient depth for many phylogenetic analyses and can therefore provide insights into within-host HCV evolutionary dynamics without the need for haplotype reconstruction using statistical algorithms. IMPORTANCE Next-generation sequencing has revolutionized the study of genetically variable RNA virus populations, but for phylogenetic and evolutionary analyses, longer sequences than those generated by most available platforms, while minimizing the intrinsic error rate, are desired. Here, we demonstrate for the first time that PacBio SMRT sequencing technology can be used to generate full-length HCV envelope sequences at the single-molecule level, providing a data set with large sequencing depth for the characterization of intrahost viral dynamics. The selection of consensus reads derived from at least 7 full circular consensus sequencing rounds significantly reduced the intrinsic high error rate of this method. We used this method to genetically characterize a unique transmission cluster of sexually transmitted HCV infections, providing insight into the distinct evolutionary pathways in each patient over time and identifying the transmission-associated genetic bottleneck as well as fluctuations in viral genetic diversity over time, accompanied by dynamic shifts in viral subpopulations.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2017
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Online-Ressource
    Online-Ressource
    American Society for Microbiology ; 1993
    In:  Applied and Environmental Microbiology Vol. 59, No. 9 ( 1993-09), p. 2777-2783
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 59, No. 9 ( 1993-09), p. 2777-2783
    Kurzfassung: Incubation of five different β-chloroethers with slurries prepared from brackish water sediment or activated sludge revealed that bis(2-chloroethyl)ether and 2-chloroethylvinylether (2-CVE) were biodegradable under aerobic conditions. After enrichment, two different cultures of Ancylobacter aquaticus that are capable of growth on 2-CVE were isolated. Both cultures were also able to grow on 1,2-dichloroethane. The cells contained a haloalkane dehalogenase that dehalogenated 2-CVE, 2-chloroethylmethylether, 2-bromoethylethylether, and epichlorohydrin. Experiments with cell extracts indicated that an alcohol dehydrogenase and an aldehyde dehydrogenase were also involved in the degradation of 2-CVE. This suggests that 2-CVE is metabolized via 2-hydroxyethylvinylether and vinyloxyacetaldehyde to vinyloxyacetic acid. Enzymatic ether cleavage was not detected. 2-CVE was also degraded by chemical ether cleavage, leading to the formation of 2-chloroethanol and acetaldehyde, both of which supported growth. We propose that A. aquaticus strains may be important for the detoxification and degradation of halogenated aliphatic compounds in the environment.
    Materialart: Online-Ressource
    ISSN: 0099-2240 , 1098-5336
    RVK:
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 1993
    ZDB Id: 223011-2
    ZDB Id: 1478346-0
    SSG: 12
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    In: Journal of Virology, American Society for Microbiology, Vol. 80, No. 22 ( 2006-11), p. 11009-11018
    Kurzfassung: Swine influenza viruses (SIV) naturally infect pigs and can be transmitted to humans. In the pig, genetic reassortment to create novel influenza subtypes by mixing avian, human, and swine influenza viruses is possible. An SIV vaccine inducing cross-protective immunity between different subtypes and strains circulating in pigs is highly desirable. Previously, we have shown that an H3N2 SIV (A/swine/Texas/4199-2/98 [TX98]) containing a deleted NS1 gene expressing a truncated NS1 protein of 126 amino acids, NS1▴126, was attenuated in swine. In this study, 4-week-old pigs were vaccinated with the TX98 NS1▴126 modified live virus (MLV). Ten days after boosting, pigs were challenged with wild-type homologous H3N2 or heterosubtypic H1N1 SIV and sacrificed 5 days later. The MLV was highly attenuated and completely protected against challenge with the homologous virus. Vaccinated pigs challenged with the heterosubtypic H1N1 virus demonstrated macroscopic lung lesions similar to those of the unvaccinated H1N1 control pigs. Remarkably, vaccinated pigs challenged with the H1N1 SIV had significantly lower microscopic lung lesions and less virus shedding from the respiratory tract than did unvaccinated, H1N1-challenged pigs. All vaccinated pigs developed significant levels of hemagglutination inhibition and enzyme-linked immunosorbent assay titers in serum and mucosal immunoglobulin A antibodies against H3N2 SIV antigens. Vaccinated pigs were seronegative for NS1, indicating the potential use of the TX98 NS1▴126 MLV as a vaccine to differentiate infected from vaccinated animals.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2006
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    In: Journal of Virology, American Society for Microbiology, Vol. 86, No. 19 ( 2012-10), p. 10597-10605
    Kurzfassung: Control of swine influenza A virus (IAV) in the United States is hindered because inactivated vaccines do not provide robust cross-protection against the multiple antigenic variants cocirculating in the field. Vaccine efficacy can be limited further for vaccines administered to young pigs that possess maternally derived immunity. We previously demonstrated that a recombinant A/sw/Texas/4199-2/1998 (TX98) (H3N2) virus expressing a truncated NS1 protein is attenuated in swine and has potential for use as an intranasal live attenuated influenza virus (LAIV) vaccine. In the present study, we compared 1 dose of intranasal LAIV with 2 intramuscular doses of TX98 whole inactivated virus (WIV) with adjuvant in weanling pigs with and without TX98-specific maternally derived antibodies (MDA). Pigs were subsequently challenged with wild-type homologous TX98 H3N2 virus or with an antigenic variant, A/sw/Colorado/23619/1999 (CO99) (H3N2). In the absence of MDA, both vaccines protected against homologous TX98 and heterologous CO99 shedding, although the LAIV elicited lower hemagglutination inhibition (HI) antibody titers in serum. The efficacy of both vaccines was reduced by the presence of MDA; however, WIV vaccination of MDA-positive pigs led to dramatically enhanced pneumonia following heterologous challenge, a phenomenon known as vaccine-associated enhanced respiratory disease (VAERD). A single dose of LAIV administered to MDA-positive pigs still provided partial protection from CO99 and may be a safer vaccine for young pigs under field conditions, where dams are routinely vaccinated and diverse IAV strains are in circulation. These results have implications not only for pigs but also for other influenza virus host species.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2012
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    In: Journal of Virology, American Society for Microbiology, Vol. 86, No. 4 ( 2012-02-15), p. 2212-2220
    Kurzfassung: Since its initial identification in St. Petersburg, Russia, the recombinant hepatitis C virus (HCV) 2k/1b has been isolated from several countries throughout Eurasia. The 2k/1b strain is the only recombinant HCV to have spread widely, raising questions about the epidemiological background in which it first appeared. In order to further understand the circumstances by which HCV recombinants might be formed and spread, we estimated the date of the recombination event that generated the 2k/1b strain using a Bayesian phylogenetic approach. Our study incorporates newly isolated 2k/1b strains from Amsterdam, The Netherlands, and has employed a hierarchical Bayesian framework to combine information from different genomic regions. We estimate that 2k/1b originated sometime between 1923 and 1956, substantially before the first detection of the strain in 1999. The timescale and the geographic spread of 2k/1b suggest that it originated in the former Soviet Union at about the time that the world's first centralized national blood transfusion and storage service was being established. We also reconstructed the epidemic history of 2k/1b using coalescent theory-based methods, matching patterns previously reported for other epidemic HCV subtypes. This study demonstrates the practicality of jointly estimating dates of recombination from flanking regions of the breakpoint and further illustrates that rare genetic-exchange events can be particularly informative about the underlying epidemiological processes.
    Materialart: Online-Ressource
    ISSN: 0022-538X , 1098-5514
    Sprache: Englisch
    Verlag: American Society for Microbiology
    Publikationsdatum: 2012
    ZDB Id: 1495529-5
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie auf den KOBV Seiten zum Datenschutz