Alimentary Bacteriology Practice Test 2026 - Free Bacteriology Practice Questions and Study Guide

Salmonella taxonomy is organized in three levels: species, subspecies, and serotype. There are two species in the genus, with most clinical and foodborne Salmonella falling under Salmonella enterica, which itself contains several subspecies (for example, enterica, diarizonae, arizonae, and others). Within a subspecies, strains are differentiated by their antigenic makeup in the Kauffmann-White scheme, yielding many serotypes (serovars) based on the combination of O (somatic) and H (flagellar) antigens. This tripartite framework—species, subspecies, and serotype—provides both a genetic lineage and a practical naming system used in epidemiology and outbreak tracking. The other options don’t fit because taxonomy isn’t defined just by genera and family for Salmonella, nor is it limited to clones, lineages, or strains alone; those terms describe population groups or genetic relationships, not the formal taxonomic hierarchy.