GLORIA

GEOMAR Library Ocean Research Information Access

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
Filter
Publikationsart
Erscheinungszeitraum
  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 243 (2005), S. 0 
    ISSN: 1574-6968
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: Tolerance to antimicrobial agents is a universal phenomenon in bacteria which are no longer multiplying or whose growth rate slows. Since slowly multiplying bacteria occur in clinical infections, extended periods of antimicrobial chemotherapy are needed to eradicate these organisms and to achieve cure. In this study, the molecular basis of antibiotic tolerance was investigated using transposon mutagenesis. We screened 5000 Escherichia coli Tn10Cam mutants for reduction of kanamycin tolerance in late stationary phase and found that 4935 mutants were able to grow to late stationary phase. Reduced tolerance was observed in nine mutants which became sensitive to killing by kanamycin. The mutant KS639 was the most sensitive one to kanamycin, and its genome was disrupted in an intergenic region which lies between aldB and yiaW open reading frames. This mutant showed increased sensitivity not only to kanamycin but also to gentamicin, ciprofloxacin and rifampicin. Reduced tolerance of KS639 to kanamycin was also observed in a murine thigh infection model. P1 transduction to the wild type strains confirmed that the intergenic region was responsible for the tolerance of the bacterium to antibiotics. Using PCR-directed one-step gene replacement, we inactivated the genes aldB, yiaW and yiaV. We also deleted the intergenic region. There was no difference in kanamycin tolerance between each mutant (ΔaldB, ΔyiaW and ΔyiaV) and the parental strain. But the mutant lacking the intergenic region showed reduced tolerance to kanamycin. These data suggest that the intergenic region between aldB and yiaW genes may be involved in tolerance to antimicrobial agents in E. coli. Furthermore, they show that it is important in murine infection during antibiotic treatment and lead to a faster kill of the mutant bacteria.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 237 (2004), S. 0 
    ISSN: 1574-6968
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: Sigma factors are important global regulators which control bacterial gene expression during growth and in response to stress. Previous work showed that mRNA of the sigJ gene was up-regulated in late stationary-phase and after rifampicin treatment. In order to verify the function of SigJ, we constructed a Mycobacterium tuberculosis mutant lacking the sigJ gene. In a microaerophilic stationary-phase model, the sigJ mutant showed the same growth pattern as the wild-type strain. In an immune stasis murine model in which the bacterial number plateaued between the second and the 15th week, the mutant showed a similar growth curve to the wild-type strain. However, the sigJ mutant was more susceptible to killing by H2O2 than its parental strain. The parental level of sensitivity to H2O2 was recovered in the sigJ complemented strain. These data suggest that the SigJ protein is not essential for survival in long-term stationary phase or in bacterial stasis in mice. However, the sigJ gene may control an alternative H2O2 resistance pathway.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 202 (2001), S. 0 
    ISSN: 1574-6968
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: In order to determine which genes are involved in maintaining viability of 100-day stationary-phase bacteria and persistent bacteria after antibiotic treatment, we used a mini-DNA array to examine the transcription of 82 genes of M. tuberculosis in the 100-day stationary-phase cultures before and after rifampicin treatment. We found that the mRNA level of a sigma factor gene, sigJ, was strongly up-regulated in the late stationary-phase cultures. Other genes were also up-regulated, although to a lesser extent than sigJ. Surprisingly, after rifampicin treatment there was no significant change in sigJ expression, and most of the other 82 genes in the mini-DNA array also maintained expression, some at relatively high levels. These results suggest that SigJ may control gene expression in the quiescent state and may be an important component in the mechanisms by which M. tuberculosis survives prolonged stationary phase even in the presence of sterilising antibiotics.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    [s.l.] : Nature Publishing Group
    Nature medicine 4 (1998), S. 537-538 
    ISSN: 1546-170X
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Medizin
    Notizen: [Auszug] To the editor—Soldan et al. report an increased IgM response to HHV-6 early antigen (p41/38) and detection of serum HHV-6 DNA in relapsing-remitting MS1 and, confirming the work of Challoner et al.2, propose an association between HHV-6 and the etiology and pathogenesis of MS. We urge caution ...
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...