Persister cells and antibiotic resistance: an overview

Abstract

Persister cells are antibiotic-tolerant phenotypic variants that can survive exposure to high concentrations of antibiotics. Among all pathogens, a subset of the population usually exhibits this phenotypic attribute. Usually, when there is a decrease in antibiotic concentration, those cells that survive (persister) repopulate the population. There are diverse mechanisms by which these cells persist or withstand exposure to harsh environments. Interestingly, among all the major pathogens, persister cells have been found. Difficulty in treating most infections is usually due to certain cell populations not responding to antibiotic treatment. Thus, persister cells are implicated in antibiotic resistance, a major public health issue. They also have some association with biofilm formation and might be playing a central role in causing the difficulty in eradicating most chronic infectious diseases. Persistence could arise through different mechanisms, and resulting bacteria can withstand antibiotic treatment by developing resistance to drugs or exhibiting tolerance to them. The proportion of these persisters within a bacterial population tends to rise due to diverse stress factors, including exposure to antibiotics with bactericidal properties. So far, diverse models have been put forth to elucidate the mechanisms underlying the emergence of bacterial persistence. However, the exact mechanisms leading to persister formation remain elusive. This review delves into the recent advancements in understanding bacterial persisters and considers the implication of persister cell formation in treating bacterial infection. It also discusses the association of persistent cells with antibiotic resistance and diseases.