A marked Copy of the Manuscriptinfluence of Oxyr on Susceptibility of Planktonic and Sessile Escherichia Coli Cultures to Ciprofloxacin and Cefotaxime

Effect of OxyR on antibiotic susceptibility

  • Zoya Samoilova Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia http://orcid.org/0000-0002-8637-6484
  • Nadezhda Muzyka Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia http://orcid.org/0000-0002-4888-1471
  • Galina Smirnova Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia http://orcid.org/0000-0001-6116-8147
  • Oleg Oktyabrsky Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia
Keywords: biofilms, antibiotics, RpoS, OxyR and SOS regulons, Escherichia coli

Abstract

Alternation of bacterial antioxidant defense pathways might affect susceptibility to antibiotics in dual ways.  Using a relatively simple model based on wild-type and oxyR Escherichia coli mature biofilms, their counterpart planktonic cultures and exponentially growing planktonic cultures, we explored the role of OxyR-mediated metabolism alternations in modulation of susceptibility to antibiotics ciprofloxacin and cefotaxime. All three types of cultures were placed in fresh medium,1 h after antibiotics were added and incubation continued further for 2 h. Killing rates of antibiotics were determined, biofilm eradication using crystal violet assay was estimated, expression of rpoS, katG, sulA genes as well as HPI and HPII catalase activity were measured. Biofilms of both strains were more recalcitrant to ciprofloxacin and cefotaxime at all tested concentrations compared to exponentially growing planktonic cultures. In oxyR biofilms killing rate of ciprofloxacin was lower, and killing rate of cefotaxime was higher compared to the parental strain. Compared to biofilms, wild-type biofilm counterpart planktonic cultures showed higher tolerance to low doses of ciprofloxacin, while oxyR plankton demonstrated higher tolerance to cefotaxime. Higher recalcitrance of oxyR biofilms to ciprofloxacin may be caused by an increase in persister cells under conditions of enhanced oxidative stress and activated SOS response.

Author Biographies

Zoya Samoilova, Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia

 

 

Nadezhda Muzyka, Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia

 

 

Oleg Oktyabrsky, Laboratory of Physiology and Genetics of Microorganisms, Institute of Ecology and Genetics of Microorganisms, Russian Academy of Sciences, Perm Federal Research Center, Perm, Russia

 

 

Published
2020-11-28
How to Cite
Samoilova, Z., Muzyka, N., Smirnova, G., & Oktyabrsky, O. (2020). A marked Copy of the Manuscriptinfluence of Oxyr on Susceptibility of Planktonic and Sessile Escherichia Coli Cultures to Ciprofloxacin and Cefotaxime: Effect of OxyR on antibiotic susceptibility. Iraqi Journal of Science, 61(11), 2812-2819. https://doi.org/10.24996/ijs.2020.61.11.5
Section
Biology