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Uropathogenic Escherichia Coli and Tolerance to Nitric Oxide: The Role of Flavohemoglobin

2006; Lippincott Williams & Wilkins; Volume: 175; Issue: 2 Linguagem: Inglês

10.1016/s0022-5347(05)00144-8

1527-3792

Lovisa Svensson, Britt‐Inger Marklund, Mirjana Poljakovic, Katarina Persson,

Nitric Oxide and Endothelin Effects

No AccessJournal of UrologyInvestigative urology1 Feb 2006Uropathogenic Escherichia Coli and Tolerance to Nitric Oxide: The Role of Flavohemoglobin Lovisa Svensson, Britt-Inger Marklund, Mirjana Poljakovic, and Katarina Persson Lovisa SvenssonLovisa Svensson Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author , Britt-Inger MarklundBritt-Inger Marklund Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author , Mirjana PoljakovicMirjana Poljakovic Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania More articles by this author , and Katarina PerssonKatarina Persson Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(05)00144-8AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: NO has an important role as part of the innate host response against bacterial infections. Flavohemoglobin, which is encoded by the hmp gene, protects Escherichia coli against nitrosative stress. We compared the NO tolerance of UPEC and nonpathogenic strains, and examined the involvement of flavohemoglobin. Materials and Methods: The E. coli K12 derivates HB101 and DH5α represent nonpathogenic strains, while J96 and IA2 represent UPEC strains. HB101 was used as the host for a pBR322 plasmid carrying the hmp gene. Bacterial tolerance to NO was evaluated by determining cfu. Flavohemoglobin expression was examined using Northern and Western blot analysis. Results: In the stationary growth phase, J96 was significantly more tolerant to DETA/NO (Alexis Biochemical, Lausen, Switzerland) (1 mM) compared to HB101 (47% ± 11% vs 6.4% ± 3.1% cfu). In the exponential growth phase DETA/NO exposure resulted in 98% ± 4.6% cfu for J96 and 74% ± 7.6% cfu for IA2 compared to 15% ± 5.9% for HB101 and 21% ± 12% for DH5α. HB101 over expressing hmp showed increased tolerance to DETA/NO (0.5 mM) compared to WT HB101 (106% ± 5.6% vs 67 ± 6.2%, p <0.01). Northern and Western blot analysis demonstrated increased flavohemoglobin expression after DETA/NO exposure and the strongest expression in HB101 carrying hmp on a multicopy plasmid. Conclusions: UPEC strains were significantly more tolerant to DETA/NO than nonpathogenic strains, which suggests a correlation between virulence and NO tolerance. Flavohemoglobin expression increased after DETA/NO exposure in UPEC and in nonpathogenic strains. References 1 : Antimicrobial reactive oxygen and nitrogen species: concepts and controversies. Nat Rev Microbiol2004; 2: 820. Google Scholar 2 : Urinary nitrite: more than a marker of infection. Urology1997; 50: 189. Google Scholar 3 : Nitrate, bacteria and human health. Nat Rev Microbiol2004; 2: 593. 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Google Scholar © 2006 by American Urological AssociationFiguresReferencesRelatedDetails Volume 175Issue 2February 2006Page: 749-753 Advertisement Copyright & Permissions© 2006 by American Urological AssociationKeywordsUSP proteinbladdernitric oxideE coliflavohemoglobin denitrosylaseAcknowledgmentProf. R. K. Poole, Sheffield, United Kingdom provided rabbit polyclonal antibody against E. coli Hmp.MetricsAuthor Information Lovisa Svensson Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author Britt-Inger Marklund Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author Mirjana Poljakovic Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania More articles by this author Katarina Persson Department of Chemistry and Biomedical Sciences, University of Kalmar, Kalmar, Sweden More articles by this author Expand All Advertisement PDF downloadLoading ...