Yersinia pestis

What is the technical term for the “safety pin” appearance of Y. pestis?

Bipolar staining

Which form of the plague is transmitted human to human via respiratory droplets?

Pneumonic plague (black)

What is the 24 hour rule for pneumonic plague?

Mortality is 100% if not treated within 24 hours

What specific “needle-like” system does Y. Pestis use to inject proteins?

Type III secretion system (TTSS)

what are “yops”

Proteins injected by the bacteria to block phagocytosis/paralyze immune cells.

Is Yersinia gram-positive or gram-negative?

Gram-Negative

What is the mortally rate of untreated bubonic plague

40-60%

Which form of plague invokes direct invasion of the bloodstream

Septicemia plague

How many people were killed during the Egyptian plague (Ad 541)?

30-50 million

Many died during the Western Europe plague (1347-1351)

Over 25 million people

Where did the third major pandemic (1993-1924) originate? And how many did it kill?

Hong Kong, 100,000 people

True or false bubonic plague is found world wide today?

true mostly in developing countries

Bubonic plagues features

Acute, Contagious, Fabrile

Yersinia pestis

Gram-Negative

Coccobacillus

Bipolar-staining

Enterbacteriaceae

Produce a thick anti-phagocyticnslime layer in its path

Virulence factor 1

The ability to use motility and other means to contact host cells and disseminate within a host

Virulence factors 2

The ability to adhere to just cells and resist physical removal

Virulence factor 3

Can invade host cell

Violence factor 4

The ability to compete for iron and other nutrients

Virulence 5

The ability to evade the innate immune system responses: Phagocytosis and Complement

Virulence 6

The ability to evade the adaptive immune system defenses

While in flea

Develops slime layer proteins

Enters?

Through bite

After bite?

Enters lymphatic system looking for the nearest lymph node in order to start replicating

Players

Brown rats, Black rats, Yersinia pestis, Oriental Rat Flea: Xenopsylla Cheopis

Infection of?

Lymphocytes and Lymph nodes first

Mechanism of pathology 2?

Fever and swelling

Mechanism of pathology 3?

Activation of type III secretion system (TTSSS)

Mechanism of pathology 4?

Secondary infection of broad range of cells and tissue