Salmonella

Abstract

Salmonella is a ubiquitous rod-shaped member of the family Enterobacteriaceae. Thanks to the ability to swiftly adapt to diverse environments, this human pathogen can infect a multitude of hosts, animals, plants, and protozoa and can colonize diverse environments. This characteristic makes this pathogen a major public health threat that cannot be eradicated, only identified and contained. In developed and industrialized countries, Salmonella spp. contaminate mainly animal products and produce, whereas in developing countries, waterborne transmission and person-to-person transmission play a more important role. There are as many as 130 million cases of nontyphoidal salmonellosis worldwide each year, and of those, about 80 million are foodborne. In the United States alone, nontyphoidal Salmonella is responsible for approximately 1.2 million illnesses and more than 450 deaths each year. These estimates make nontyphoidal Salmonella serovars the leading cause of bacterial foodborne illness. This chapter provides a detailed historical perspective on the discovery, nomenclature, and characterization of this microorganism. The discussion covers the classification of this complex taxon based on the recent concepts of core genomes and pangenomes and the most prevalent isolation and identification methods currently used. The most recent understandings of virulence mechanisms and antibiotic resistance prevalence are also covered to present a complete overview of this important human pathogen.