Physiologic Stresses Reveal a Salmonella Persister State and TA Family Toxins Modulate Tolerance to These Stresses

摘要: Bacterial persister cells are considered a basis for chronic infections and relapse caused by bacterial pathogens. Persisters phenotypic variants characterized low metabolic activity slow or no replication. This state increases pathogen tolerance to antibiotics host immune defenses that target actively growing cells. In this study we demonstrate within population of Salmonella enterica serotype Typhimurium, small percentage bacteria reversibly tolerant specific stressors mimic the macrophage environment. Numerous studies show Toxin-Antitoxin (TA) systems contribute states, based on toxin inhibition metabolism growth. To identify toxins may promote in response host-associated stressors, analyzed six TA loci S. serotypes cause systemic infection mammals, including five RelBE family members one VapBC member. Deletion increased decreased depending stress conditions. Similarly, exogenous expression had mixed effects survival stress. macrophages, Typhimurium induced three examined. These observations indicate distinct have protective capabilities but also suggest both positive negative tolerance.