The Error-Prone Polymerase DnaE2 Mediates the Evolution of Antibiotic Resistance in Persister Mycobacterial Cells

Abstract

Applying antibiotics to susceptible bacterial cultures generates a minor population of persisters that remain susceptible to antibiotics but can endure them for extended periods. Recent reports suggest that antibiotic persisters (APs) of mycobacteria experience oxidative stress and develop resistance upon treatment with lethal doses of ciprofloxacin or rifampicin. However, the mechanisms driving the de novo emergence of resistance remained unclear. Here, we show that mycobacterial APs activate the SOS response resulting in up-regulation of the error-prone DNA polymerase DnaE2. The sustained expression of dnaE2 in APs led to mutagenesis across the genome and resulted in the rapid evolution of resistance to antibiotics. Inhibition of RecA by suramin, an anti- Trypanosoma drug, reduced the conversion rate of persisters to resistors in a diverse group of bacteria. Our study highlights suramin's novel application as a broad-spectrum agent in combating the development of drug resistance.

dnaE2expression promotes genetic diversity and bacterial persistence in mycobacterial biofilms

“…3E, medial value of 8.9×10 −8 for WT in comparison to 5.8×10 −8 for ΔdnaE2 ). Since the expression of dnaE2 reduces during recovery into planktonic phase of growth (Table-1), we performed a time course expression analysis of dnaE2 during recovery stage using a dual reporter harboring a P hsp ∼mClover and P dnaE2 ∼mCherry 38 . While there was expression of P dnaE2 ∼mCherry at the time of biofilm disruption (0 h) the expression significantly reduced between 3 to 6 hrs (Fig.…”

RecA-NT homology motif in ImuB is essential for mycobacterial ImuA’-ImuB protein interaction and mutasome function

“…S2). The potential importance of the mycobacterial mutasomeminimally comprising ImuAʹ, ImuB, and DnaE2in M. tuberculosis evolution and acquisition of drug resistance has been recognized previously 1,2,19,20 . We are optimistic the results presented will allow for a better understanding of the assembly and operation of this mutagenic machinery, and will inform ongoing efforts towards developing novel "anti-evolution" drugs [21][22][23][24] for M. tuberculosis and other organisms encoding homologous systems.…”

A brief report on the of mycobacterial proteins regulated by the loss of PtkA in Mtb-H37Ra

“…The frequent use of antibiotic generates antibiotic persisters (AP) in the cultures. These AP Mtb experience oxidative stress and activates SOS response resulting in upregulation of DnaE2 and develop resistance to the lethal dose of ciprofloxacin or rifampicin (Salini S. et.al, 2022).…”