Exam 3 Lecture 25 Flashcards
What are zoonotic infections?
Infections that are transmitted between humans and other vertebrate animals
True or False: Infections in other animal hosts are frequently asymptomatic or mildly symptomatic.
False.
How can zoonotic infections be transmitted?
- Cutaneous contact
- Arthropod vector
- Inhalation
- Ingestion
What occupations are at risk for zoonotic infection?
- Farmers
- Hunters/Fishermen
- Slaughterhouse workers
- Vets/Lab workers
- Pet owners
___ of pathogens that infect humans are zoonotic.
58%
Zoonotic infections are likely to arise in _______ tropical regions with land-use changes and ____ wildlife biodiversity.
forested
high
What is the one health triad?
the health of people, animals, and the environment are linked together
Humans went from a _________ society to an ________ society.
Hunter-gatherer, agrarian
___ do very well in urban environments, which is become an increasing problem with increased population density.
Rats
Modification of the _______ leads to more interactions between the human population and natural population of different environments, thus creating opportunity for ______ to spread and jump the species barrier.
Environment modification, pathogens
What are the 3 CDC classifications of biological agents?
category A, category B, category C
What is category A defined as?
- easily transmitted from person to person
- high mortality rate
- creates public panic/social disruption
- requires public health action
What is category B defined as?
- moderately easy to disseminate
- result in moderate morbidity and low mortality
- require increased diagnostic capacity & surveillance
What is category C defined as?
- available
- ease of production and dissemination
- potential for high morbidity and mortality
Yersinia pestis and francisella tularensis fall in category __
A
Brucella spp. fall in category __
B
The ____ death killed as many as ___ of people in Europe in the middle ages
25%
Yersinia pestis is gram _______
negative
True or False: Yersinia does not stain well, it stains mostly at the ends and can look like cocci instead of a rod.
True
Name Yersinia virulence factors
Yersinia outer proteins (YOP), antiphagocytic capsule, coagulase-fibrinolysin, plasminogen activator
_________ facilitates iron acquisition
yersiniabactin
what is enzootic spread?
non-human animals are affected at the expected frequency
what is epizootic spread?
non-human animals are affected at a higher frequency than expected
what is zoonotic spread?
spread of a pathogen from animals –> humans
What is the treatment for plague?
streptomycin/gentamycin, doxycycline, fluoroquinolones
What are ways to prevent plague?
Rodent/vector control, vaccine for high-risk ppl
the ____ __ was important during the black death, found in urban settings, they are susceptible to Yersinia, and support high level bacterial growth
black rat
the _____ __ has outcompeted the black rat in urban settings, and are usually ______ to the plague. this is thought to be a reason for decreasing cases in Europe.
norway rat
Yersinia pestis DNA was found in _____ ___ from 16th c. French plague victims
dental pulp
Ancestral Y. pestis strains are not very _____ from modern Y. pestis strains
different
True or False: Yersinia pestis evolved from other Yersinia species and had to acquire genes that allowed it to spread from arthropod vectors
True
____ & ____ genes are needed for biofilm promotion in flea, causing obstruction of the GI tract, making it continue to feed b/c its belly does not feel full
Hms, Ymt
The ability for Yersinia pestis to spread via fleas is more ____ than thought. The plasmid ___ locus is required for growth in fleas, and is missing from ancient Yersinia.
recent
Ymt
Yersinia pestis has a type __ secretion system, which allows Y. pestis to secrete _____ to kill host macrophages.
3
YopK
Y. pestis spreads ______ thru a lymph node, whereas __ ___________ contains granulomas.
uniformly
Y. pseudotuberculosis
What helps Y. pestis spread in the host?
A plasminogen-activating protease
True or False: A single ship, called S.S. Australia is known to have introduced the plague in 1900, and the plague is now stably endemic in part of the US
true
As the great gerbil population rises and falls based on ____ _______, so does the plague population.
food availability
________ __ has been used increasingly to identify Y. pestis
MALDI-TOF MS
_______ disease may be linked to resistance to plague
Chron’s
_____ mutations enhance resistance to Yersinia infections are associated w/ _____ disease
Chron’s
What bacteria causes tularemia?
Francisella tularensis
Describe the gram stain of francisella tularensis
Gram-neg coccobacillus
F. tularensis usually requires ____
cysteine
True or false: F. tularensis is able to survive intracellularly and grow in the cytoplasm of macrophages
True
F. tularensis has a type ___ secretion system, which is used to inhibit the _______ and ……. ….
6
inflammasome
cytokine release
