What is the fine-grained topic of the following text: An aspect of the study is to look at how pathogenic microorganisms sense and respond to their environment for survival and pathogenesis, such as Listeria monocytogenes bacteria that utilises an RNA switch that encodes virulent proteins that harm the body. Only return the topic.
How pathogenic microorganisms, specifically Listeria monocytogenes, sense and respond to their environment for survival and pathogenesis.