chapter 12: Yersinia, Francisella, Brucella, and Pasteurella Flashcards
all of these are
G negative rods
zoonotic
very aggressive/virulent disease in humans
site of contact is usually the skin
generally factultative intracellular organisms who tend to spread to regional LNs and then to vital organs
Yersinia pestis animals it comes from
bubonic plague
rats are the PEST that harbor disease, fleas are vectors carrying it to humans
no in squirrels and praire dogs of southwestern US
virulence factors of yersinia pestis
F1: antiphagocytic properties
V and W antigens: protein and lipoprotein respectively are unique to this genus but fnct unknown
-all part of resistance to phagocytosis in macrophage
what kind of staining does yersinia pestis have
bipolar staining pattern
-ends of rod take up more stain than center
Yersinia pestis when enter human after flea what happens
macrophage eats and still reproduce intracellulary, move to nearest LNs
- usually inguinal LNs, become swollen, hot, red
- fever and headache set in
- hemmorhage under skin cause black discoloration
if a person has been doing what activity suspect that yersinia pestis may be involved
camping in new mexico or arizona and has fever
francisella tularensis
- resembles what
- acquired from what
resembles bubonic plague, always involved in differential
acquired from handling infected rabits and from bites of ticks and deerflies
diseases caused by francisella tularensis
and symptoms
what else can it invade
ulceroglandular tularemia: hole in the skin with black base develops
-fever and systemic symptoms develop
local LNs become swollen red, painful
-symptoms almost identiacla to plague but no skin ulcer in plague (mortality rate lower in this disease)
pneumonic tularemia: aerosolization of bacteria during skinning of infected rabit or from spread from skin to lungs can lead to lung infection (pneumonia)
can also invade eyes (oculoglandular tularemia) and GI tract (typhoidal tularemia)
brucella named by species it infects
melitensis (goats)
abortus (abortions in cows)
suis (pigs)
canis (dogs)
how do humans get brucella
prevalent in US? world?
direct contact with infected animal meat or aborted placentas, or ingestion of infected milk products
-rare in US, more common in world than bubonic plague and tularemia
brucella penetrates
-skin ulcer?
skin, conjunctiva, lungs, GI trat
-no primary skin ulcer
what are the symptoms of brucella
-unique one?
systemic ones
undulant fever
-peaking fever in evening and slowly returns to normal by morning
pasteurella multocida
-facultatgive intracellular organism?
associated with what animals
no
dog and cat bites
what people are most likely to be pateints that have brucella
meat packing industry worker
veterinarian
farmer
traveler who consumes dairy in mexico
