yersinia and strep Flashcards
Yersinia types
Y. enterocolitica
Y. pestis
Bacteria in Yersinia genus
gram-negative bacilli
Yersinia bacteria are
facultative anaerobes
Y. enterocolitica main idea
causes food poisoning and mimics appendicitis
Y. pestis main idea
causes plague
Yersinia is able to divide quickly
at temps as low at -2 degrees C
Yersinia is able to contaminate
contaminate refrigerated samples
Yersinia bacteria are also…..
zoonotic
zoonotic
normal hosts are other animals
examples of host of Yersinia
RATS, rabbits, prairie dogs, squirrels, chipmunks
Yersinia loves
iron
since yersinia loves iron it’s classified as
siderophilic
who are most succptible to Yersinia infections
people with hemochromatosis
hemochromatosis
high iron levels
what is the most common contaminant of blood transfusions
Y. enterocolitica
how many samples of blood are contaminated with Y. enterocolitica
1 in 1 million
people who receive a blood sample contaminated with Y. enterocolitica
quickly enter septic shock, mortality rate over 50%
Because Y. enterocolitica is gram-negative,
it has endotoxin (LPS)
prescence of LPS from Y. enterocolitica in the bloodstream causes
widespread inflammation, strong immune reaction
symptoms of blood transfusion with Y. enterocolitica
hypotension, fever, shivering
symptoms of blood transfusion with Y. enterocolitica set in
within 3 hours of transfusion
why is food contaminated with Y. enterocolitica
because of urine or feces of rats
once food contaminated with Y. enterocolitica is eaten
bacteria get eaten by macrophages, but cannot be destroyed
when Y. enterocolitica can’t be destroyed by macrophages
macrophages unknowingly carry bacteria to Peyer’s patches of the small intestine
Peyer’s patches
lymph-like regions of the small intestine.
digested material passes through the Peyer’s patches
passes through them and must pass through many macrophages and dendritic cells.
Peyer’s patches are like
surveillance system for food and drink… or a breeding ground for Y. enterocolitica
when macrophages carry Y. enterocolitica to Peyer’s patches
Bacteria grow and “arm” themselves, then eventually pop out, ready for a bigger war
when macrophages carry Y. enterocolitica to Peyer’s patches ……….. and arm and grow and attack
causes swelling and inflammation that mimics that of appendicitis
Y. enterocolitica colonies produce
yst toxin
what does yst toxin do
binds to receptors on cells in the GI tract
when yst toxin binds to receptors on cells in the GI tract
causes intestines to secrete more cGMP
cGMP
cyclic guanosine monophosphate
when intestines to secrete more cGMP
channels that absorb water from the small intestine slam shut
Result of intestines to secrete more cGMP and channels that are responsible for absorbing water from the small intestine slam shut
extra water in the GI tract, which leads to diarrhea
what accompanies diarrhea when channels that absorb water from the small intestine slam shut
abdominal pain, fever and sometimes…vomiting
Y. enterocolitica food poisoning is also sometimes associated with
erythema nodosum
erythema nodosum comes from
an exaggerated and delayed immune response to a Yersinia antigen
erythema nodosum
splotchy patches usually confined to fatty tissue in the legs
Yersinia pestis has identified
as the causative agent of the european plague outbreaks
outbreak of Yersinia pestis often called
bubonic plague
3 ways Y. pestis an infect
- bubonic plaque
- pneumonic plague
- septicemic plague
bubonic plague
Flea bite or other vector bite permits bacterial entry to the body
bubonic plague death rate w/ o treatment
75%
pneumonic plague
bacteria are inhaled through droplets and enter lungs
pneumonic plague mortality rate without treatment
99%
septicemic plague
Y. pestis bacteria enter bloodstream, usually through open wound
septicemic plague mortality rate w/o treatment
99%
Y. pestis forms a ____ in the _______
forms a biofilm in the gut of the oriental rat flea
when Y. pestis forms a biofilm in the gut of the oriental rat flea
causes a small amount of bacteria to be regurgitated with each bite
Aside from biofilm formation Y. pestis does not
does not harm the flea
1894
outbreak of plague struck southern China
who cam to investigate outbreak of the plague in china
Shibasaburo Kitasato from JAPAN
who cam to investigate theh plague inchina 3 days later
Alexandre Yersin
what did Kitasato examine
the organs and blood of dead bodies and jndentified an unknown microbe
what did Kitasato do with the microbe to test it
isolated it, put it in rats, and quickly saw rats die.
what happened to the lymph nodes of rats with the bacteria
lymph nodes of the rats were overwhelmed with the same bacteria.
what did kitasato do with the bacteria he teste
took slides to london to be published…. but they WERE MESSEY
Kitasato messy slides were
contaminated w other bacteria
Yersin got access…
to cadavers for his own research»_space;> SHADY
with his cadavers Yersin was able to
produce a purer slide 6 days later»_space;> credited with the discovery of the bacillus»»YERSIN-ia.
black plague
- most infamous world crisis of infection
- cutting population of europe in HALF during 1300s
main waves of Y. pestis
Justinian plague
Black Death
Third Wave
Justinian plague
600s– killed 40% of population of Constantinople
Black death.
mid 1300s killed half of europe’s population
Third Wave
late 1800s in southern china and india… killed 12 million before vaccine discovered
After a bit, Y. Pestis is able to grab onto _______
extracellular collagen with the help of pla protein
pla (PESTIS)
plasminogen activator
pla converts
host cell plasminogen into plasmin
what does plasmin do
break apart fibrin tissues in clots
by breaking up fibrin……. the plague
the plague is able to invade into further tissue
when is Yersinia killed by the body
phagocytosed by neutrophils
what is usallly NOT recruited to fight Yersinia
dendritic cells
Yersinia is NOT KILLED
not killed by macrophages
what happens when Yersinia is eaten by macrophage
waits inside the phagosome, using it as an “oven” to “cook” many proteins that will help it invade the human» POPS OUT
when Y. pestis pops out of a macrophage
shifts gears completely
when Y. pestis pops out of a macrophage and shifts gears it STOPS
creating the proteins that protected it from a phagosome
when Y. pestis pops out of a macrophage and shifts gears it STARTS
produces different anti-phagocytic proteins so the new bacteria can’t be eaten
what anti-phagocytic proteins does Y.pestis produce after shifting gears
yops
yops
Yersinia outer proteins
when Y. pestis shifts gears it eneters
antiphagocytic mode
when Y. pestis is in antiphagocytic mode
multiplies rapidly in the lymph nodes and causes the formation of a bubo or many buboes
buboes
hugely inflamed lymph nodes.
once Y. pestis is in the lymph nodes
eventually can make it into the blood
once Y. pestis is in the blood
secretes endotoxins that lead to the formation of many tiny blood clots
when Y. pestis secretes endotoxins that lead to the formation of many tiny blood clots it is called
DIC
DIC
disseminated intravascular coagulation
what does DIC do
- cuts off circulation to extremities(further away parts)
- results in acral necrosis
acral necrosis
a blackening of tissue especially in fingers and toes.
why is black plague the name
acral necrosis
eventually, the tiny blood cots caused by Y. Pestis releasing endotoxins in the blood
cut circulation to organs and DEATH
plague is treated with
antibiotics… miniscule mortality rate if treated early
RED ALERT PLAGUE
Antibiotic-resistant strain of Y. pestis found in Madagascar
Streptococcus bacteria
gram-positive cocci
how many species in the Streptococcus genus
at least 37
how many species of Streptococcus can be pathogenic in humans
5 in immunocompetent humas
ALL STREP BACTERIA
obligate parasites of human mucosa
what does it mean to be .a obligate parasites of human mucosa
can’t reproduce without finding a host
biggest three species Streptococcus
S. pyogenes, S. agalactiae, S. pneumoniae
S. pyogenes gist
strep throat and much more
S. agalactiae
Infant pneumonia and meningitis
S. penumoniae
Pneumonia, ear infection, sinus infection, meningitis
first tests to diminish the many gram-positive cocci
coagulase and catalase tests
for species that both turn up _____ on coagulase and catalase tests
both turn up negative: series of tests for surface antigens devised
series of tests for surface antigens of gram-positive cocci that is negative on coagulase and catalase tests DEVISED BY
Rebecca Lacefield
Rebecca Lancefield breaks bacteria into what groups
Lancefield groups
Easier to examine virulence factors of Streptococcus bacteria by
examining whole group rather than species by species
what Lancefield groups exist
groups A-V
do all strep bacteria fit into one Lancefield group
NO
clinically relevant Strep bacteria fall in what Lancefield group
group A or B or cannot be grouped
Hemolysis S. pyogenes
Beta
Hemolysis S. agalactiae
Beta
Hemolysis S. pneumoniae
Alpha
Lancefield group S. pyogenes
Group A
Lancefield group S. agalactiae
Group B
Lancefield group S. pneumoniae
NO GROUP
Disease Associated w/ group A strep
- Strep Throat (Pharyngitis)
- Impetigo
- Scarlet Fever
- Cellulitis
- Pneumonia
- Streptococcal TSS
- Necrotizing Fasciitis
- Rheumatic Fever
- PANDAS?
BRUH
main virulence factor in group A strep
membrane protein M protein
M protein extends
from the membrane beyond cell surface
M protein allows
S. pyogenes to avoid phagocytosis by neutrophils and macrophages
M protein ALSOOOO
stops antibody binding
M protein binds to
human fibrinogen, giving it a camouflage
when the M protein binds to human fibrinogen…..
only a small bit protrudes beyond this
how many unique M protein structures have been observed
over 100
to beat strep (M proteins)
body has to produce antibodies that bind to a particular strain of M protein’s tip
many different M protein structures is an example of……
ANTIGENIC VARIATION
rheumatic fever
severe condition associated w/ S. pyogenes infections
Rhematic fever usually develops how long after the initial infection
2-4 weels
Regions of the M protein have……………
amino acid sequence very similar to cardiac myosin
because regions of M protein have amino acid sequence very similar to cardiac myosin
antibodies fighting the infection can wrongly recognize heart muscle as bad guy
Role of M protein in rheumatic fever first 2
- colonization of throat» severe inflammation
- M protein enters bloodstream and elicits antibody response
Role of M protein in rheumatic fever after elicitign antibody response
- antibodies-cross react with heart tissue
- autoimmune response damages heart valves
more virulence factors in group A Strep
- M-like protein
- Hyaluronidase
- MSCRAMMs
- SPEs
M-like protein
surface protein that grabs Fc region of random antibodies and holds them
purpose of M-like protein
camouflage
Hyaluronidase
breaks down hyaluronic acid,»_space; increase spread of bacteria through body
MSCRAMMs
Promote attachment to epithelium
SPEs
Streptococcal pyrogenic exotoxins
SPEs are different ….
Different strains release different exotoxins
ranges of SPEs
SpeA to SpeJ
the TYPES OF SPEs we need to know
SpeA
SpeB
SpeA
in the blood can lead to STSS (Streptococcal toxic shock syndrome)
STSS
Streptococcal toxic shock syndrome
SpeA is a ….
SUPERANTIGEN
SpeB
cuts many proteins like fibronectin
fibronectin
extracellular protein that connects collagens
result of SpeB cutting fibronectin
This leads to breakdown of skin in the area
result of SpeB cutting fibronectin»_space;> but the infection is superficial»>
redness
result of SpeB cutting fibronectin»_space;> but the infection is DEEP»_space;>
Necrotizing fasciitis
Necrotizing fasciitis
s an infection of the fascia, a deeper skin layer
if in Necrotizing fasciitis, the infection spreads through this layer ….
BAD THINGS HAPPEN
what is the main species of Group B strep
S. agalactiae
the bacteria of group B strep
do not typically infect humans
the bacteria of group B strep are a member of
the normal flora in about 20% of female vaginas.
do group B strep cause infection in the vagina…
NO, but is a risk of inhalation of a new born during child birth
because infants ______ inhalation of group B strep (S. agalactiae) can cause
have a weak immune system…. can lead to pneumonia and or meningitis
because of the risks of group B strep to infants preg woman should
be testes and be administered antibiotics before birth
S. pneumoniae is commonly found
in the pharynx of humans, is harmless there
S. pneumoniae can do bad things when
go other places
S. pneumoniae can cause…… BRUH
ear infection
sinus infection
pneumonia
brain infection
brain infection is ie
MENINgitis
usually the places that S. pneumoniae infects are
protected by cilia
S. pneumoniae infections are often a result of
previous infection that impedes cilia function
what are infectious diseases caused by
viruses, bacteria, fungi , parasites
most bacteria is not is not dangerous
yes
clinically significant
bacteria that are linked to disease
like other species, how are bacteria named
by binomial nomenclature
what is binomial nomenclature
two words: genus and species
typically many species for
for one genus
binomial nomenclature should always be
italicized in print
underlined in writing
first letter of genus in binomial nomenclature
capitalized
species name in binomial nomenclature
entirely lower case
there are often many species
in a genus
members of a species can _____ through
vary a lo through horizontal gene transfer
what is the genetic material of bacteria
one large circular chromosome… called plasmid