What is the etiologic agent responsible for plague?

Yersinia pestis is the etiologic agent responsible for plague, a severe infectious disease that primarily affects rodents but can also infect humans and other animals. This bacterium is characterized as a Gram-negative rod and is transmitted to humans through the bites of infected fleas, direct contact with infected animals, or inhalation of respiratory droplets from infected individuals.

Understanding Yersinia pestis and its role in plague is crucial for public health, particularly since plague can lead to significant morbidity and mortality if not recognized and treated quickly. Historical pandemics, such as the Black Death in the 14th century, highlight the impact of this pathogen on human populations, underscoring the importance of knowledge regarding its transmission and prevention.

In contrast, the other options listed are associated with different diseases and pathogens. Escherichia coli is typically linked to gastrointestinal infections, Salmonella typhi causes typhoid fever, and Staphylococcus aureus is known for a variety of infections, including skin infections and food poisoning. Each of these pathogens has unique characteristics and disease associations, ensuring a clear distinction from Yersinia pestis, which is specifically responsible for plague.