Test 1: bacillus Flashcards
___ are gram positive rods families that form spores
bacillus
clostridium
___ are gram positive rods that do not form spores and are regular shaped and staining
listeria
erysipelothrix
what are two species of bacillus
Bacillus cereus
bacillus anthracis
Bacillus anthracis
(gram + rod, forms spores, catalase +)
bacillus are gram ___ ___ shaped bacteria.
positive rod shaped
bacillus are obligate ___ or facultative ___
aerobes
anaerobes
(gram + rods, catalase +)
bacillus are catalase positive or negative
positive
(gram + rods, form spores)
when do bacillus anthracis form spores
all conditions except in the living body → where it grows and multiplies
37 degrees Celcius
what two virulence factors keep anthrax alive inside the body
polypeptide capsule
exotoxins
(bacillus anthracis, gram + rods that form spores)
3 types of anthrax
cutaneous – spores enter through skin, black sore-eschar; least dangerous
pulmonary –inhalation of spores
gastrointestinal – ingested spores
what type of anthrax has the highest survival rate?
cutaneous anthrax
(bacillus anthracis, gram + rods that form spores)
the capsule around anthrax allows for ___
antiphagocytic → prevents host cell from eating it
(bacillus anthracis, gram + rods that form spores)
explain how inhaled anthrax kills
In haled anthrax is particularly deadly. Although the spores are dormant when breathed in, they germinate when exposed to a warm, moist environment, such as the lungs. Not all particles are small enough to pass into the alveoli, or air sacs, but those that do begin to multiply and may spread to the lymphatic system. When the spores germinate in the lymph nodes, several toxins are released.
(bacillus anthracis, gram + rods that form spores)
___ are the primary hosts for anthrax
___ are the accidental hosts
herbivores (cows)
humans ( caused by eating or touching infected host)
why does anthrax survive well in tropical climates
goes through phases of sporulation and vegetative growth with the dry and wet seasons
alkaline soils, with high nitrogen levels (decaying vegetation)
symptoms of anthrax in ruminants
Typical presentation is septicemia
Symptoms:
- Sudden onset
- High fever, bleeding from body openings
- Edema
- Peracute death in 1-2h, acute in <24 h
(bacillus anthracis, gram + rods, that form spores)
symptoms of anthrax in horses
colic, edematous swellings of the throat, neck, shoulders
(bacillus anthracis, gram + rods, that form spores)
anthrax life cycle
prevention of anthrax
vaccinations
cull sick animals
proper PPE
how to diagnose inhalation anthrax
Xay
gram stain blood and culture → gram + rods
ELISA and immunohistology testin
what drugs treat anthrax
penicillin (beta lactam → attack cell wall)
tetracycline/chloramphenicol → (MCAT: inhibit protein synthesis → broad spectrum against weird bugs)
erythromycine/clindamicine → (MCAT: Lincosamide: inhibit protein synthesis- anaerobic growth)
anthrax capsule is made of ___
S-layer increases resistance to complement attack
capsule made of D-glutatmate that is antiphagocytic
anthrax capsule made of ___ that is antiphagocytic
D-glutatmate
what are the three components of anthrax toxin
protective antigen
edema factor
lethal factor
Expression of anthrax’s virulent factors is regulated by host ___
temperature and carbon dioxide concentration
how does anthrax kill
anthrax spore will invade macrophage cell (capsule protects it from being eaten)
it will grow and release toxins into the host
Protective antigen will bind to a cell and act as docking station for edema factor and lethal factor
edema factor will inhibit immune response and decrease activity of macrophages
lethal factor: is an enzyme that inhibits macrophage signaling and causes rapid pro inflammatory cell death
Protective antigen
will bind to a cell and act as docking station for edema factor and lethal factor
toxin made by anthrax
edema factor
will inhibit immune response and decrease activity of macrophages
toxin made by anthrax
lethal factor:
is an enzyme that inhibits macrophage signaling and causes rapid pro inflammatory cell death
what drug is used to treat inhalation anthrax
ciprifloxacin
what gene encodes for protective antigen in anthrax?
pOX1 (plasmid) → also encodes for edema factor and lethal factor
Bacillus anthracis (gram + rod, forms spores)
what does pOX1 code for
encode Protective Antigen (PA), Edema Factor, Lethal Factor
Bacillus anthracis (gram + rods, form spores)
what does pOX2 plasmid encode for?
encodes capsule – D-glutamate residues, antiphagocytic capsule
Bacillus anthracis (gram + rods, produce spores)
Erysipelothrix rhusiopathie
can be small gram + rods or filamentous if smooth colonies are stained
Erysipelothrix rhusiopathie
can be small gram + rods or filamentous if rough colonies are stained
Erysipelothrix rhusiopathie has ___ hemolysis
alpha → greenish/ incomplete
coagulase +
gram + rod/filamentous
non spore forming
____ is a gram + rod that is pathogenic in swine and poultry
Erysipelothrix rhusiopathie
non spore forming
how do animals shed Erysipelothrix rhusiopathie
urine, feces, saliva ect
can survive in alkaline soil (exogenous source of infection)
can also be found on scales of fresh and salt water fish
(gram + rod, non spore forming)
3 forms of swine erysipelas
Acute septicemic.
subacute septicemic
chronic form
acute septicemic
swine erysipelas → caused by Erysipelothrix rhusiopathie (gram + rod, no spores)
- Sudden occurrence of high fever associated with endotoxin and peptidoglycan.
- Clinical signs include inappetence, depression, conjunctivitis, vomiting, that will lead to coma and death.
- Hemorrhagic (ulcers) mucosa of stomach and small intestine are observed.
subacute septicemic
swine erysipelas → caused by Erysipelothrix rhusiopathie (gram + rod, no spores)
Many develop pathognomonic urticarial lesions
(Rhomboidal or diamond skin disease). -
Necrosis of defined areas of the skin which will peel off to leave an ulcer
subacute septicemic swine erysipelas
→ caused by Erysipelothrix rhusiopathie (gram + rod, no spores)
diamond skin disease
Chronic form of swine erysipelas
vegetative endocarditis
with or without non suppurative erosive arthritis
swine erysipelas → caused by Erysipelothrix rhusiopathie (gram + rod, no spores)
what happens to birds with Erysipelothrix rhusiopathie
turkeys are most susceptible to infection leading to sudden death with high mortality. Pathology characterized by diarrhea, massive petechial hemorrhages, gut filled with blood.
gram + rod, no spores
what age pigs are susceptible to erysipelas
3-18 months old
what happens to calves and lambs with Erysipelothrix rhusiopathie
Cause polyarthritis in 2 to 3 month old. Wound infection is the mode of transmission.
(gram + rod with no spores)
what antibiotic for Erysipelothrix rhusiopathie
penicillin, tetracycline, streptomycin
Erysipelothrix rhusiopathie is resistant to ___
kanamycin & sulfadimethoxazine.
(gram + rod, no spores)
antiserum for E. rhusiopathiae is effective ___
both prophylactically and therapeutically
EVA
Erysipelas vaccine avirulent (EVA) or glyco-lipoprotein- containing vaccines are effective.
vaccine for Erysipelothrix rhusiopathie
(gram + rod, no spores)
___ is the major cause of food borne disease
listeria
(gram + rod, no spores)
listeria causes ___
non-enteric damage (meningitis, septicemia and abortion)
fatal 20-30%
(gram + short rod, no spores)
Of the seven listeria species, only ___ affects humans
L. monocytogenes
___ is common in soil, decaying vegetation, fecal flora
of many mammals (including 15% of healthy
adults)
listeria
___ is found in raw vegetables, raw milk, fish, poultry, meats, esp. deli meats (15-70%)
listeria
___ : grows at low temperature
psychrotropic
listeria can grow at 4 degree Celsius (in the fridge)
listeria prefer to grow in what conditions
aerobic/ faculative anaerobic
37 (0-42)
resistant to low pH, high sodium (in stomach)
what do listeria look like
gram + short rods
non- sporulating
no capsule
how do listeria get into cell
have surface protein internalin that binds to E-cadherin receptors on epithelial cells
will cause zipper phagocytosis into the cell
listeria have surface protein ___ that binds to___ receptors on epithelial cells
internalin
E-cadherin
how do listeria spread from cell to cell
Listeria’s surface protein “internalin” interacts with E- cadherin, a receptor on epithelial cells → zipper phagocytosis
listeriolysin O will break down endosome around listeria
virulence factor Act A will take over actin production
will use actin to propel/ break into neighboring cells
___ lyses the phagolysosomal membrane around listeria inside a cell
Listeriolysin O
In cytoplasm, listeria bacteria divides approx. __
every hour
Listeria uses virulence factor ___ to induce host cell actin
polymerization
Act A
___ propel the listeria bacteria to the host cell membrane.
Actin filaments
Listeria bacteria push against cell membrane to form ___
“filopods”.
Listeria has moved from cell to cell without being exposed to ___
antibodies, complement, or neutrophils.
if there is a double membrane vacuole around listeria that means ___
second cell
lifecycle of listeria
gram + short rod, no capsule, no spore
___ can invades GI tract without erosive lesions
listeria
__ can invade the cerebral cortex and placenta
listeria (gram + short rod, no spores, no capsule)
travels inside cells, avoids detection
symptoms of listeria in human adults
Asymptomatic
– Mild influenza-like illness
– Gastrointestinal symptoms
– Meningitis in immunocompromised patients/pregnant women
– Bacteremia-fever/chills can be deadly in immunocompromised patients and neonates
– Preterm birth/abortion – bacteria cross placental barrier and infect fetus – placental inflammation
symptoms of listeria in animals
Sheep, goats, and cattle most severely affected
- Encephalitis, meningoencephalitis
- Abortion, fetal damage, or stillbirths
listeric mastitis
Approximately 4% of raw milk samples contain___
L. monocytogenes (gram + short rods, no capsule, no spores)
cause listeric mastitis
Neuromeningeal listeriosis in sheep
A - the syndrome is characterized by involuntary torticollis and walking aimlessly in circles as a result of brainstem lesions.
B -In a further step of the infectious process, animals lie on the ground with evident signs of uncoordination (paddling movements) and cranial nerve paralysis (strabismus, salivation, etc.).
___ and ___ can be used if other bacteria outgrow Listeria
Selective media and cold enrichment
listeria can grow at low temps, other bacteria usually can not
___ are selective agents for growth of listeria in a lab
lithium chloride
moxalactam
what kind of hemolysis does listeria cause
beta hemolysis
(clear)
___ is used to treat listeria
penicillin, ampicillin (beta lactam → attack cell wall)
can be used in combo with gentamycin
___– gram-positive (small slender rods on staining).
Erysipelothrix
subacute/septicemic form is associated with pathognomonic urticarial lesions (Rhomboidal or diamond skin disease). Necrosis of defined areas of the skin which will peel off to leave an ulcer.
Erysipelothrix – gram-positive (small slender rods on staining).
short gram-positive rods (appear similar to cocci)
listeria
___ is a faculative intracellular pathogen – replicates within the host cell cytosol.
listeria
listeria use array of virulence factors to invade, escape from vacuole, and uses ____ to move within cytosol and spread from cell-to-cell
*actin-based motility*
what temp can listeria grow
0-42
(can grow in the fridge)
what kind of foods grow listeria
raw vegetables, raw milk (4% of all raw milk supplies contain Listeria), fish, poultry, meats, esp. deli meats (15-70%).
