One for All, but Not All for One: Social Behavior During Bacterial Diseases

Trends in Microbiology, Cell Press

2019 Jan;27(1):64-74

PMID: 30243514

DOI: 10.1016/j.tim.2018.09.001

Abstract

It has been known for decades that individual cells within pathogenic bacterial populations have reduced antibioticsusceptibility, which is linked to decreased metabolic rates. A similar phenomenon occurs with virulence-associated proteins, as reduced expression is associated with increased fitness of individual cells. Non-producers within the population can benefit from the virulence proteins produced by others in the population without suffering a fitness cost, thus maintaining a genetically uniform population. Cooperative behavior has been reported for Salmonella and Yersinia, consistent with selection of social behavior to retain genes associated with pathogenesis; however, cooperation was unclear within Mycobacterium populations. This review focuses on these recent descriptions of cooperation, discusses the mechanisms driving heterogeneity, and evaluates the evidence that expression of virulence-associated proteins comes at a fitness cost.