Which of the Following is a Primary Pathogen

Question

Which of the following is a primary pathogen?
A) Staphylococcus aureus
B) Streptococcus pneumoniae
C) Yersinia pestis
D) Papillomavirus
E) MRSA (methicillin-resistant S. aureus)

Accepted Answer

Primary pathogens do not need to wait for a wound to gain access to their host. The human pathogen Yersinia pestis, for example, survives in the flea's foregut, and uses the flea as a vector to spread from one mammalian host to another.