Antibacterial activity of acidified nitrite against pathogenic E.coli

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. Sub-MIC of acidified sodium nitrite can result in inhibition of biofilm-formation and make bacteria be more sensitive to antibiotics, while sub-MIC of nitrite alone can enhance bacterial growth and further colonizing. Synergistic effects can be obtained by combination of acidified sodium nitrite with each of the ciprofloxacin, nitrofurantoin and nalidixic acid. In contrast, antagonistic effect can be achieved by combination of ascorbic acid with ciprofloxacin.