Which Salmonella serotype has a broad host range and is common?

• A. Paratyphi A
• B. Enteritidis
• C. Typhimurium
• D. Newport

Answer: (C)

Salmonella serotypes differ in how many and which animals they can infect. Typhimurium is the one that can live in a wide variety of hosts—from birds and livestock to wildlife and humans—so it shows a broad host range and is a common source of human illness. In humans, non-typhoidal Salmonella often presents as gastroenteritis, and Typhimurium is frequently isolated, reflecting its broad ecological footprint. The other serotypes have more limited or different patterns: for example, Paratyphi A mainly infects humans and causes paratyphoid fever, Enteritidis is common and widespread in poultry and eggs but doesn’t outpace Typhimurium in terms of multi-host reach, and Newport is also found in multiple hosts but is less commonly encountered. Therefore, Typhimurium best fits the idea of a broad host range and being common.