title: Urinary tract infection in iNOS-deficient mice with focus on bacterial sensitivity to nitric oxide.
abstract: Inducible nitric oxide synthase (iNOS)-deficient mice were used to examine the role of iNOS in Escherichia coli-induced urinary tract infection (UTI). The toxicity of nitric oxide (NO)/peroxynitrite to bacteria and host was also investigated. The nitrite levels in urine of iNOS+/+ but not iNOS/ mice increased after infection. No differences in bacterial clearance or persistence were noted between the genotypes. In vitro, the uropathogenic E. coli 1177 was sensitive to 3-morpholinosydnonimine, whereas the avirulent E. coli HB101 was sensitive to both NO and 3-morpholinosydnonimine. E. coli HB101 was statistically (P < 0.05) more sensitive to peroxynitrite than E. coli 1177. Nitrotyrosine immunoreactivity was observed in infected bladders of both genotypes and in infected kidneys of iNOS+/+ mice. Myeloperoxidase, neuronal (n)NOS, and endothelial (e)NOS immunoreactivity was observed in inflammatory cells of both genotypes. Our results indicate that iNOS/ and iNOS+/+ mice are equally susceptible to E. coli-induced UTI and that the toxicity of NO to E. coli depends on bacterial virulence. Furthermore, myeloperoxidase and nNOS/eNOS may contribute to nitrotyrosine formation in the absence of iNOS.
authors.affiliation: Department of Clinical Pharmacology, Lund University Hospital, Sweden.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Poljakovic
authors.forename: Katarina
authors.initials: K
authors.lastname: Persson
mesh_terms: D000818:Animals; D000906:Antibodies; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D005260:Female; D005838:Genotype; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009393:Nephritis / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000652:urine; D009195:Peroxidase / Q000276:immunology / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000276:immunology / Q000378:metabolism; D014552:Urinary Tract Infections / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology
chemical_list: D000906:Antibodies; D009573:Nitrites; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D009195:Peroxidase; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496317:Nos2 protein, mouse; C496315:Nos3 protein, mouse