Digestion & Metabolism 2: Bacterial Pathophys Flashcards
E. COLI causes both ____ & ____ DZ
has 2 functions….
3 types of DZ they can cause?
causes both SYSTEMIC & GI DZ
2 functions…
1. PROTECT against other bad pathogens
2. can CAUSE DZ
3 types of DZ they can cause?
1. NO dz (COMMENSAL)
2. EXTRAINTESTINAL DZ (UTI, PNEUMONIA)
3. INTESTINAL DZ
what can help determine if E. coli is PATHOGENIC or not?
CAN BE SPECIES-SPECIFIC for the HOST
2 types of INTESTINAL pathogenic e. coli (BASIC, 2 subs for each)
TOXIGENIC…
1. ENTEROTOXIGENIC
2. SHIGA TOXIN (EHEC)
NON-TOXIGENIC
1. ENTEROPATHOGENIC (EPEC)
2. ADHERENT & INVASIVE (AIEC)
ENTEROPATHOGENIC E. COLI (EPEC)…
what TYPE of E. coli is this? (3 words)
species/what it causes?
characteristic lesions?
INTESTINAL PATHOGENIC NON-TOXIGENIC
causes MALABSORPTIVE D+ IN ALL SPECIES, INCLUDING HUMANS!
lesions = PEDESTALS, attaching and effacing lesions on INTESTINAL VILLI
ADHERENT-INVASIVE E. COLI (AIEC)
what TYPE of E. coli is this? (3 words)
pathophys? (2)
Dx made via… (2 things)
most common in WHAT BREED & causes WHAT DZ?
INTESTINAL PATHOGENIC NON-TOXIGENIC
pathophys?
1. bacteria INVADE ENTEROCYTES & lives in VACUOLES
2. causes PROLIFERATIVE LESIONS that causes CHRONIC INFLAMMATION
diagnosis?
1. BIOPSY to see BACTERIA IN ENTEROCYTES
2. + FISH to TARGET & FLUORESCE E. COLI DNA
COMMON IN BOXERS, BOXER DOG COLITIS
what treatment can be used for BOXER DOG COLITIS?
what kind of DZ is this?
can use ENROFLOXACIN (baytril)
INTESTINAL PATHOGENIC NON-TOXIGENIC E. COLI
ENTEROTOXIGENIC E. COLI (ETEC)…
causes ____ ____ in ____ SPECIES, including… (4)
the D+ is ____, meaning that it is… (2)
2 types of TOXINS that can be released?
HOW does toxin each work?
causes NEONATAL D+ in MANY SPECIES, including…
1. CALVES
2. LAMBS
3. PIGLETS
4. FOALS
D+ is SECRETORY, so…
1. WATERY
2. NON-BLOODY
2 types of TOXINS
1. HEAT LABILE = toxin CAN be denatured with heat
2. HEAT STABLE
how does each TOXIN work?
1. HEAT LABILE = activates ADENYLATE CYCLASE –> cAMP to PREVENT Na ABSORPTION & INCREASE Cl SECRETION
- HEAT STABLE = ACTIVATES GUANYLATE CYCLASE –> GMP, same process
SHIGA…
what TYPE of DZ is this? (3 words)
what SPECIES does this cause DZ in? MOSTLY ONE, sometimes THE OTHER
in ADULT animals, causes… (2)
in YOUNG animals, causes… (1)
binds to WHAT receptor & WHERE? what 2 things does this then cause?
INTESTINAL PATHOGENIC TOXIGENIC
MOSTLY causes DZ in PRIMATES, but also PIGS
ADULT animals…
1. BLOODY D+
2. SYSTEMIC DZ
YOUNG animals…
1. ACUTE DEATH
binds to Gb3 RECEPTOR on ENDOTHELIAL cells & REMOVES ADENINE FROM RIBOSOME to STOP PROTEIN SYNTHESIS, so BLOODY D+
E. COLI SHIGA toxin in PIG EDEMA DISEASE
causes WHAT 4 clinical signs?
in the US, this DZ is…
4 c/s…
1. EDEMATOUS EYELID
2. EDEMA in BRAIN
3. NEUROLOGIC DZ w/ PADDLING
4. SUDDEN DEATH
in the US, this DZ is RELATIVELY WELL-CONTROLLED
ID DZ
what KIND of toxin is this?
PIG EDEMA DZ (E. coli ENTEROTOXEMIA)
this is a SHIGA toxin
ENTEROHEMORRHAGIC E. COLI (EHEC)…
produces WHAT 3 pathogenic things?
what does O157:H7 mean?
MOSTLY causes disease in WHAT SPECIES? what species is a NATURAL ASYMPTOMATIC RESERVOIR?
can POTENTIALLY cause WHAT DZ?
produces…
1. ATTACHING lesions
2. EFFACING lesions
3. SHIGA TOXINS
O157:H7 = ANTIGENIC MAKEUP, same thing
mostly causes DZ in HUMANS, but ADULT CATTLE are NATURAL ASYMPTOMATIC RESERVOIR
can POTENTIALLY cause HEMOLYTIC UREMIC SYNDROME
how is ENTEROHEMORRHAGIC E. COLI spread to HUMANS? (5)
- RAIN/RUNOFF carries it to crops
- BIRDS carry it to crops
- HUMAN-HUMAN contact
- POORLY CHLORINATED pools
- SEPTIC water
what MEDIUM is E. COLI grown on?
medium = MACCONKEY AGAR is used
ALL POOP HAS WHAT?????
so that means we TECHNICALLY need to test for what?
ALL POOP HAS E. COLI ON IT
TECHNICALLY we could test for TOXINS or OTHER VIRULENCE FACTORS, but this is NOT EASY OR CHEAP
PCR diagnosis of E. coli…
helps to ID what?
this is the ___ & MOST ____ used method to ID…
ID of TOXIN GENES based on pathology findings
this is the EASIEST & MOST COMMONLY used method to ID WHICH E. COLI WE’RE WORKING WITHS
SALMONELLA…
is very sensitive to WHAT? what does this mean?
often a ___-borne DZ because…
what is the most COMMON SALMONELLA species in ____?
sensitive to STOMACH ACID, meaning WE NEED A LOT OF SALMONELLA TO CAUSE DZ
often a FOODBORNE dz because CAN EAT A LOT OF IT
SALMONELLA ENTERICA is most common in MAMMALS
is SALMONELLA TYPHI seen in animals? what does it cause?
NOT seen in animals
causes TYPHOID FEVER
HOW is salmonella TRANSMITTED?
2 specific examples in DOGS?
1 example in LIVESTOCK?
1 example in HORSES?
transmitted via FECAL-ORAL
in DOGS…
1. RAW FOOD DIETS!!
2. JERKY/PIG EARS also linked
in LIVESTOCK…
1. PASTURE/FEED contamination from RODENTS/BIRDS
in HORSES…
1. NOSOCOMIAL
HOW does SALMONELLA cause disease pathophysiologically? (3)
what can POSSIBLY occur in IMMUNOCOMPROmISED individuals?
usually salmonella DOES/DOESN’T cause D+ IMMEDIATELY after infection
pathophys?
1. salmonella enters gut from food
2. can INVADE THROUGH ENTEROCYTES via PEYER’S PATCHES and cause SEVERE INFLAMMATION
3. cause D+
for NON-HOST SPECIFIC strains of SALMONELLA, causes ____ D+ for an _____ period, around ____-____ days post-exposure & RARELY causes ____ infections
MILD, ACUTE, 3-5, SYSTEMIC
SEPTICEMIA in HOST-RESTRICTED serovars means that they…
CANNOT CAUSE INFECTION IN ANOTHER SPECIES! EVER
HOST-ADAPTED SEPTICEMIA SEROVARS means that they
CAN cause D+ in other species but SEPSIS IN ADAPTED SPECIES
DIAGNOSIS of SALMONELLA via CULTURE requires…
can also use WHAT diagnostic method?
why can a SINGLE negative culture NOT RULE OUT SALMONELLA?
if D+ and SALMONELLA present, is that enough to prove it? why or why not?
Dx requires…
1. ENRICHMENT BROTHS
2. SPECIALIZED MEDIA (for growth)
can also use PCR
SINGLE negative culture can’t rule it out because SALMONELLA SHED INTERMITTENTLY
NOT ENOUGH TO PROVE bc SALMONELLA CAN BE ASYMPTOMATIC (not the cause of D+)
TREATMENT for SALMONELLA for…
SUPPORTIVE therapy?
D+ only?
SYSTEMIC DZ? (4 options)
SUPPORTIVE therapy = salmonella usually SELF-LIMITING
D+ only = NO ANTIBIOTICS bc can cause RESISTANT STRAINS
SYSTEMIC DZ…
1. TMS
2. CHLORAMPHENICOL
3. 3RD GEN CEPHALOSPORIN
4. FLUOROQUINOLONES
CAMPYLOBACTER…
3 potential shapes?
gram +/-?
unique morphological structure it has?
requires WHAT to grow?
3 potential shapes?
1. CURVED
2. SPIRAL
3. S-SHAPED
gram NEGATIVE
unique structure?
1. MOTILE from ONE POLAR FLAGELLUM
requires SPECIFIC MICROAEROPHILIC CULTURE to grow!
THERMOPHILIC CAMPYLOBACTER…
grows at ___C but NOT ___C
present as WHAT kind of organism in WHAT location in WHAT species?
how is it transmitted? has a very ___ infectious dose
grows at 42C but NOT 25C
present as COMMENSALS in INTESTINES of BIRDS
transmitted FECAL-ORAL, has LOW INFECTIOUS DOSE (500 cells OK)
C. JEJUNI…
what GENUS is this?
3 species it infects?
1. CHICKEN (fowl)
2. CATTLE
3. DOGS
THERMOPHILIC CAMPYLOBACTER
C. COLI…
what GENUS is this?
what 2 species does it infect?
CAMPYLOBACTER
2 species?
1. PIG
2. DOGS
4 options for DIAGNOSIS of CAMPYLOBACTER?
which one is MOST COMMONLY DONE?
- MICROSCOPY = gram stain of FECAL SMEAR
- CULTURE on SENSITIZED medium
- SUSCEPTIBILITY testing
- PCR MOST COMMONLY DONE
what does “BEWARE CLOs” mean?
CAMPY-LIKE ORGANISMS that can appear on MICROSCOPY of CAMPYLOBACTER (gram stain fecal smear)
many animals can be ____ for CAMPYLOBACTTER, and this is common in YOUNG ____ (specifically what age?)
with WHAT CHRONICITY/WHAT CLINICAL SIGN should we test for CAMPYLOBACTER?
should we use antibiotics?
what SPECIFIC drug SHOULD NOT BE USED/WHY?
ASYMPTOMATIC, common in YOUNG DOGS <6 MONTHS
IF CHRONIC D+ >2 WEEKS, TEST FOR CAMPYLOBACTER
NOT RECOMMENDED TO USE ANTIBIOTICS BC WE DON’T KNOW IF IT HELPS
DO NOT USE FLUOROQUINOLONES bc causes RESISTANT STRAINS
CLOSTRIDIA characteristic appearance?
what is the KEY to diagnosing this?
looks like BACTERIA with CLEARING IN THE MIDDLE
KEY to diagnosis = TOXIN DETECTION, NOT JUST ORGANISM PRESENCE
CLOSTRIDIUM DIFFICILE causes WHAT gross sign?
animals with C. diff usually had WHAT in their history?
what 2 SPECIES does it DEFINITELY cause disease? what 2 SPECIES does it SOMETIMES?
BEST diagnostic method for this?
PSEUDOMEMBRANOUS COLITIS = fibrinous mats that cause “membrane” over GI tract
usually PREVIOUS ANTIBIOTIC TREATMENT
DEFINITELY causes disease…
1. HORSES
2. PIGS
SOMETIMES causes disease…
1. CATS
2. DOGS
DIAGNOSIS = PCR with TOXIN AS TARGET
what organism CAN we use METRONIDAZOLE FOR D+?
CLOSTRIDIUM DIFFICILE
