Signaling Pathways Sustaining Antibiotic Resistance: Lessons From Methicillin-Resistant Staphylococcus aureus

Multidrug-resistant bacteria constitute a major public health burden, as these lethal pathogens of fish, birds, and mammals cause difficult-to-treat health care–associated or community-acquired infections in humans. Indeed, recent information from the World Health Organization highlighted that drug-resistant infections already kill hundreds of thousands a year globally, and by 2050, that figure could be more than 10 million, with an associated economic burden of up to $100 trillion, if prompt actions are not taken. Staphylococcus aureus is a leading cause of fatal bacterial infections worldwide, with a death rate of about 20% of cases in industrialized countries (and even more in developing countries). Moreover, the economic implications of growing methicillin-resistant S. aureus (MRSA) incidence in community patients and farm animal lineages suggest that the burden of MRSA infections could even be more considerable than reported. This chapter endeavors to review the state of the knowledge of biological processes and signaling molecules accounting for the development of resistance in bacteria, with a particular emphasis on evidence from resistant and persistent variants of S. aureus .