Human Microbial Diseases Flashcards
What is Bubonic Plague?
Infection of rodents, which is accidentally transmitted to humans via flea bites
Caused by the bacterium Yersina pestis
One of the great epidemics that wiped out much of Europe’s population in the 8th to 14 centuries and heralded the end of the Middle Ages; also known as “The Black Death
What is Yersinia pestis?
Causative organism of bubonic plague
Gram negative ovoid bacillus (sometimes referred to as a coccobacillus) belonging to Enterobacteriaceae
Stains heavily at each end of the bacterium but not in the midsection, giving a “safety pin” or bipolar staining appearance.
Facultative intracellular organism
Fermentative metabolism
Non-motile
Bacterium can survive and multiply inside monocytes but not inside neutrophils
What are virulence factors?
Yersinia pestis is extremely virulent
Bacterium produces a thick antiohagocytic capsule/slime layer
Bacterium produces two anti-phagocytic components only when grown at 37oC
These are the F1 antigen and VW antigen