The antibacterial effect of acidified nitrite on uropathogenic Escherichia coli: In vitro study
Keywords:
Urine acidification, Antibacterial agent, NitriteAbstract
Background and objectives: Urinary acidification induces strong antibacterial effect against different bacterial types involved in urinary tract infections. The aim of this study is to assess in vitro determination of the minimal inhibitory concentration of nitrite alone and acidified nitrite using addition of ascorbic acid in infected urine with different pH of the bacterial media.
Methods: E.coli bacteria have been isolated from the urine of patients with urinary tract infection. Identification of E. coli was achieved using biochemical tests. Determination of bacteriostatic activity of acidified sodium nitrite was carried out using 96- wells microtiter plate. Acidification effect against UTI bacteria was assessed using sequential steps; feeding bacteria with NaNo3, then transferring them to acidified urine after incubation using ascorbic acid.
Results: Ascorbic acid (40 mM) alone and sodium nitrite (200 mM) alone are considered to be a weak antibacterial agents on uropathgenic E. coli, while mixing 10 mM ascorbic acid with 625 μM sodium nitrite at pH 5 became a strong antibacterial agent against 14 isolates out of 32. Bacterial death can occur by sequential steps, first feeding bacteria with sodium nitrate and after incubation, transferring to the acidified urine at pH 5 and pH4.6 causing bacterial death.
Conclusion: Strong antibacterial agent can be formed in acidified urine containing nitrite. This antibacterial agent is strongly pH and nitrite dependent and is increased by addition of ascorbic acid. The antibacterial strength is a nitrite-dose dependent in mildly acidified urine.
Metrics
References
Soderhall M. The importance of Escherichia coli fimbriae in Urinary tract infection. Ph.D. thesis, Karolinska Institutet, Stockholm, Sweden (2001)
Newell A, Riley P, Rodgers M. Resistance pattern of Urinary tract infection diagnosed in genitourinary medicine clinic. Int J STD AIDS 2000; 11(8) 499-500.
Groote, M. A. D., and F. C. Fang. NO inhibitors: antimicrobial properties of nitric oxide. Clin Infect Dis 1995; 21:S162-5.
Carlsson S, Govoni M, Wiklund NP, Weitzberg E, Lundberg JO.. In vitro evaluation of a new treatment for urinary tract infections caused by nitrate-reducing bacteria. Antimicrob Agents Chemothe 2003; 47(12): 3713-8..
Carlsson S. Antibactrrial effects of nitrite in urine. Ph.D. thesis, Karolinska Institutet, Stockholm. Sweden. (2005)
Carlsson S, Govoni M, Wiklund NP, Weitzberg E, Lundberg JO. Effects of pH, nitrite, and ascorbic acid on nonenzymatic nitric oxide generation and bacterial growth in urine.Nitric Oxide 2001:5(6):580-6
Chromek M. Urinary tract infection and renal sacrring. Ph.D. thesis, Karolinska Institute, Stockholm. Sweden. (2006)
Saginur R, Denis MS, Ferris W, Aaron SD, Chan F, Lee C, et al. Multiple combination bactericidal testing of Staphylococcal biofilms from implant-associated infections. Antimicrob Agents Chemother 2006; 50(1): 55–61.
Gavan TL, Town MA. A microdilution method for antibiotic susceptibility testing. Am J Clin Path 1970; 53:880-5.
Andrews JM. Methods for Antimicrobial Susceptibility Testing (Version 8). J Antimicrob Chemother 2009; 64(3):454-89.
Weitzberg E, Lundberg JO. Nonenzymatic nitric oxide production in humans. Nitric Oxide 1998; 2:1–7.
Lundberg JO, Carlsson S, Engstrand L, Morcos E, Wiklund NP, Weitzberg E. Urinary nitrite: more than a marker of infection. Urol 1997; 50(2):189-91.
Benjamin NF, O’Driscoll H, Duncan DC, Smith L, Golden M, McKenzie H. Stomach NO synthesis. Nature 1994; 368:502.
Hurst JK, Lymar SV. Toxicity of peroxynitrite and related reactive nitrogen species toward Escherichia coli. Chem Res Toxicol 1997; 10:802–10.
Klebanoff SJ. Reactive nitrogen intermediates and antimicrobial activity: role of nitrite. Free Radic Biol Med 1993; 14:351–60.
Downloads
Published
How to Cite
Issue
Section
License
The copyright on any article published in Zanco J Med Sci is retained by the author(s) in agreement with the Creative Commons Attribution Non-Commercial ShareAlike License (CC BY-NC-SA 4.0).
