Yersinia Flashcards
Plague epidemics contributed to devastating morbidity and mortality preceding the 19th century, causing widespread panic. Where are these places?
- Asia
- Europe
- North Africa
How did plague epidemics affect the world?
- there was death on a global scale
- referenced in art and music, literature, the horrors of death
- most impactful disease in the world, black plague
- before people could properly develop antibodies
There are 3 major plagues during this period. What are they?
- the Justinian plague
- the black plague, bubonic plague
- the modern plague
What are some defining features of the Justinian plague?
- 541 AD
- most characterized by waves of pandemicity for hundreds of years
- estimated to have killed 15% of the worlds population (>25 million)
What are some defining features of the Black death?
- started in the 14th century
- originated in China
- spread throughout trade routes to Europe
- estimated to have killed nearly 60% of the European population at the time (>100 million)
What are some distinguishing features about the Modern plague?
- started in China in the 1860’s
- spread around the world from ships
- caused an estimated 10 million deaths
State some facts about Alexander Yersin.
- french physician, pasture institute
- discovered the causative agent of the plague during the modern pandemic
- called it Pasteurella pestis at first, then later named Yersinia
Plague is spread by the bite of____.
-Oriental Rat Fleas
What was one of the ways the spread of the plague would be mitigated?
- known that humans with close contact with rats are more likely to get the plague
- the infection rate increases with increased contact with rats
- For, example rat catchers were tasked with executing rats in mostly urban areas, which brought the populations down
- live were spared and infection rated decreased
- control of a reservoir is important in controlling a disease
Y.pestis has a broad host range. What are these animals that carry the plague?
- squirrel
- chipmunks
- rats
- mouse
Reservoirs in squirrels , and other rodents allow plague to become______- including western U.S.
-endemic in many rural areas
Why is the plague prominent in the western U.S.?
- plague in the west, reported cause of human plague in the western United States
- 1970-2012, predominately in the western part of the U.S.
- wild squirrels, wild rats, prairie dogs
What can change the outcome of the plague in the U.S.?
-improved rodent control, insecticides for insect control
Yersinia is divided into at least 11 different species. What are the ones significant to this lecture?
- Y.pestis
- Y.enterocolitica
- Y.pseudotuberculosis
- the pathogenic potential of the other species is unknown
Describe the Morphology of Yersinia.
- gram-negative
- cocobacilli
- small bipolar staining “safety pin” pattern of staining by Wayson’s Method
- capsular heat envelope antigen, heat liable
- Stomatic V/W antigen associated with virulence
Describe the epidemiology of Y.pestis.
- primary a rat pathogen (sepsis)
- maintains its primary reservoir in rats and other rodents
- is able to be indirectly transmitted to humans by the bite if the rat flea, parenteral
Both Y.enterocolitica and Y.psudotuberculosis cause yersiniosis. What is this?
- generalized infection of the small/large bowl
- usually self limiting, diarrehagenic, gastrointestinal disease
- sometimes can progress to a abscess stage and gut proliferation, results in life threatening sequelae paratinitis
What is a popular diagnostic method used for direct examination of a specimen suspected to be Y.pestis?
- Wayson’s method
- stained, Y.pestis will appear purple with a safety pin appearance
Y,pestis, as well as other species of Yersinia, have the intrinsic ability to survive in immune cells. What type of strategy is this?
- pathogenic strategy
- are able to infect lymphatic tissue
- they are also able to colonize the gut, have a broad host range, species of yersinea in general
Answer these questions about Y.pestis:
- In its bubonic form, can there be direct transmission between humans?
- What does Y.pestis have to do in order to become highly contagious?
- In its bubonic form, Y.pestis does not have any way of direct transmission, contained within the individual
- The bubonic form of the disease has to progress to pneumonia, that way there can be direct transmission via aerosolization, spreads easily
- pnumonic form of the disease can be a complication of the bubonic form
Answer these questions about Y.enterocolitia:
- Y.enterocolitica is enteropathogenic to what two organisms?
- How is it transmitted?
- What type of disease does it cause if it invades M-cells?
- Ungulates ( cattle and deer), humans, also pigs
- transmitted by fecal-oral route
- causes diarrhea disease, result from the invasion of these pathogens into basil membranes through M-cells through the process of transcytosis
What are these three bacterium mode of transmission?
- Y.pestis?
- Y.enterocolitus?
- Y.psudotuberculosis?
- through vectors
- fecal-oral transmission
- fecal-oral transmission
Fill in the blank:
Bubonic plague is to _____, while _____ is to lungs.
- lymph nodes
2. Pnumonic Plague
State some facts about Pasteurella:
- What was it later called?
- What is the morphology of Pasteurella?
- Where does it largely cause disease?
- What type of infection does it cause in humans?
- later called Yersinea
- Morphology: Non-motile, gram-negative coccobacilli, retain their bipolar stain, most disease caused by P.multocida
- causes disease in animals (domestic/wild), cattle, sheep, rodents, fowl, rabbits
- causes integumental (abscess) infection in humans, there can be exposure to infected animals from arthropod vectors (deerfly/ticks)