Temperature sensing and virulence regulation in pathogenic bacteria

Pathogenic bacteria can detect a variety of environmental signals, including temperature changes. While sudden and significant temperature variations act as danger signals that trigger a protective heat-shock response, minor temperature fluctuations typically signal to the pathogen that it has moved from one environment to another, such as entering a specific niche within a host during infection. These latter temperature fluctuations are utilized by pathogens to coordinate the expression of crucial virulence factors. Here, we elucidate the critical role of temperature in governing the expression of virulence factors in bacterial pathogens. Moreover, we outline the molecular mechanisms used by pathogens to detect temperature fluctuations, focusing on systems that employ proteins and nucleic acids as sensory devices. We also discuss the potential implications and the extent of the risk that climate change poses to human pathogenic diseases.