Bicarbonate may alters bacterial susceptibility to antibiotics by targeting Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus

Backgrounds/aims: Acute acidemia is a common clinical condition in critical diseases. Acidemia is associated with poor prognosis in case of persistence. In the case of metabolic acidosis, it is beneficial to increase the pH by administering sodium bicarbonate (NaHCO3) since cell functions are impaired. The aim of this study was to investigate the antibacterial efficacy of NaHCO3 used in metabolic acidosis, especially in critically ill patients in intensive care units, and to reveal its contribution to antimicrobial therapy for possible concomitant sepsis.Method: S.aureus ATCC 29213, P. aeruginosa ATCC 27853 and E. coli ATCC 25922 strains were seeded into liquid Müller Hinton medium (Oxoid, UK) and the in-vitro effect of Group C (Control - 1 mL sterile saline) and Group B (Sodium Bicarbonate - NaHCO3) on these bacteria following 24 hours of incubation at 37 degreesC was investigated. Following the use of Epoch spectrophotometer (BioTek Inst. Inc. Vermont, USA) for the 0. and 24. hours, the growth in wells was analyzed in CFU / mL and log10 CFU/mL by comparison with the standard curve.Results:From the start to the 24. hour, there was a significant decrease in bacterial colony numbers of S.aureus ATCC 29213, P. aeruginosa ATCC 27853 and E. coli ATCC 25922 strains in Group B when compared to the control group (p <0.01). The intra-group antibacterial efficacy comparison revealed a significant decrease in bacterial colony numbers in Group B between 0-24 hours (p<0.01). There was a significant increase in all bacterial colony numbers in the control group (p = 0.04). Conclusion: In our study, NaHCO3 was found to show strong antibacterial efficacy against P. aeruginosa, E. coli and S. aureus. Taking these results into consideration, it should be kept in mind that the use of NaHCO3 in the treatment of severe metabolic acidosis especially seen in septic patients in intensive care units will also contribute to sepsis treatment because of its antibacterial effect potential. We believe that the results of this study, if supported by clinical studies, may contribute to the improvement of treatment efficacy and lower treatment costs in critical patients in the intensive care unit in the case of metabolic acidosis and sepsis.  

___

  • 1. Ingels C, Gunst J, Van den Berghe G.Endocrine and Metabolic Alterations in Sepsis and Implications for Treatment. Crit Care Clin 2018;34:81-96.
  • 2. SepNet Critical Care Trials Group. Incidence of severe sepsis and septic shock in German intensive care units: the prospective, multicentre INSEP study. Intensive Care Med 2016;42:1980-9.
  • 3. Jaber S, Paugam C, Futier E, Lefrant JY, et al. BICAR-ICU Study Group. Sodium bicarbonate therapy for patients with severe metabolic acidaemia in the intensive care unit (BICAR-ICU): a multicentre, open-label, randomised controlled, phase 3 trial. Lancet 2018 7;392:31-40.
  • 4. Reitsema VA, Star BS, de Jager VD, van Meurs M, et al. Metabolic Resuscitation Strategies to Prevent Organ Dysfunction in Sepsis. Antioxid Redox Signal 2019 10;31:134-52.
  • 5. Vishnupriya K, Falade O, Workneh A, Chandolu S, et al. Does sepsis treatment differ between primary and overflow intensive care units? J Hosp Med 2012;7:600-5.
  • 6. Polat G, Ugan RA, Cadirci E, Halici Z. Sepsis and Septic Shock: Current Treatment Strategies and New Approaches. Eurasian J Med 2017;49:53-8.
  • 7. Thompson KD, Welykyj S, Massa MC. Antibacterial activity of lidocaine in combination with a bicarbonate buffer. J Dermatol Surg Oncol 1993;19:216-20.
  • 8. Farha MA, French S, Stokes JM, Brown ED. Bicarbonate Alters Bacterial Susceptibility to Antibiotics by Targeting the Proton Motive Force. ACS Infect Dis 2018 9;4:382-90.
  • 9. Begec Z, Gulhas N, Toprak HI, Yetkin G, et al. Comparison of the antibacterial activity of lidocaine 1% versus alkalinized lidocaine in vitro. Curr Ther Res Clin Exp 2007;68:242-8.