Enterobacteriaceae

Question 1

family characteristics

Answer 1

• rod shaped
• facultative anaerobes
• gram negative
• don’t form spores
• can have capsule, can produce exotoxins (enterotoxins)
• ferment sugar

Question 2

genus: escherichia, species: escherichia coli basic info

Answer 2

• found in intestinal tract of all warm blooded animals (absent in fish, cold blooded)
• gram neg, short rods
• peritrichous flagella, capsule, no spores
• ferments lactose!!

Question 3

4 types of diseases caused by e coli

Answer 3

• enterotoxic
• enterotoxemia
• local invasive
• septicemic form

Question 4

enterotoxic (enteric colibacillosis) e coli

Answer 4

lumen of small intestine –> enterotoxin –> fluid secretion –> diarrhea –> enterotoxin unnecessary

Question 5

enterotoxemic e coli (colibacillosis)

Answer 5

small intestine –> toxin –> absorption of toxin –> action of toxin elsewhere

Question 6

local invasive e coli (colibacillosis)

Answer 6

local invasion and destruction of intestinal epithelium –> not enterotoxigenic, do not become bacteremic

Question 7

septicemic e coli (colibacillosis)

Answer 7

• bacteremia or extraintestinal localization of e coli with endotoxin mediated damage
• entry through respiratory tract or intestine

Question 8

e coli and endotoxins

Answer 8

• part of the outer layer of the cell wall
• released in soluble form during bacterial growth, liberated when bacteria lyse
• less toxic than exotoxins
• leukopenia, hypotension, complement activation, intravascular coagulation, death

Question 9

e coli and exotoxins

Answer 9

• called enterotoxins
• activate adenylate cyclase –> increased cAMP
• hypersecretion of water –> fluid loss

Question 10

2 forms of e coli in cattle

Answer 10

• septicemic (very severe, young age)

- enteric (intestinal issues)

Question 11

e coli infections in cattle

Answer 11

• septicemic colibacillosis or coli septicemia
• 4-5 day old calves
• acute –> no scouring, no fever (overwhelming)
• enteric –> calves under 2 weeks, up to 1 month (diarrhea)

Question 12

importance of colostrum to calves and e coli

Answer 12

• colostrum may inhibit the sudden and abnormal rate of multiplication of e coli
• should receive 5% of body weight within first 12 hours of birth, repeat 18-20 hours

Question 13

mastitis

Answer 13

• e coli associated with acute mastitis
• poor sanitation
• one or more quarters –> high temp, drop in milk production

Question 14

e coli in dogs/cats

Answer 14

commonly isolated pathogen in urinary tract infections, pyometra

Question 15

e coli infection in pigs (young)

Answer 15

• susceptible in first 14 weeks of age
• neonatal colibacillosis/piglet scours (1-12d old)
• diarrhea, dehydration –> high mortality
• diagnose with cultures from SI/LI

Question 16

e coli causing edema disease in pigs

Answer 16

• occurs 1 week after weaning
• acute, highly fatal neurologic disorder
• associated with dietary changes
• dependent on colonization of SI –> toxin produced (hemolysin, K88 pili antigens) –> arterial degeneration, vascular permeability

Question 17

control of e coli in pigs

Answer 17

• sanitation
• immunization of sows
• electrolytes as supportive therapy
• determine sensitivity to antibiotics

Question 18

3 types of e coli infection in poultry (colisepticaemia)

Answer 18

• neonatal colisepticaemia
• respiratory colisepticaemia
• enteric colisepticaemia

Question 19

neonatal colisepticaemia

Answer 19

• chicks within 2 days of hatching
• high mortality, stunting
• darkened lungs, splenomegaly, pericarditis, pleuritis, peritonitis, air sacculitis
• yolk sac infection from pores in egg

Question 20

respiratory colisepticaemia

Answer 20

• access the bloodstream after crossing damaged respiratory tract lining or epithelium
• tracheitis, bronchitis, pneumonia, air sacculitis, pericardits, peritonitis
• air sacs thicken –.> fibrinous forms

Question 21

enteric colisepticaemia

Answer 21

• sequel to something that has damaged lining of digestive tract
• main lesion is liver congestion
• internal lesions similar to respiratory colisepticaemia

Question 22

egg peritonitis

Answer 22

• e coli can contribute
• yolk debris, insippated tolk, caseous material
• inflammation of ovaries (salpingitis)
• some deaths

Question 23

what else can e coli contribute to (3)

Answer 23

• synovitis
• joint infections - arthritis
• septicemic conditions

Question 24

are there vaccines for e coli

Answer 24

yes –> given to pregnant female cows and pigs

Question 25

e coli in humans

Answer 25

• O157:H7
• intestines of healthy cattle and on udders
• infants, elderly especially susceptible
• diarrhea, UTIs
• hemolytic uremia syndrome, kidney failure

Question 26

e coli O157:H7 in animals

Answer 26

not perceived as an animal health pathogen

Question 27

e coli in lambs

Answer 27

• enteritis
• vulnerable in first 2 days of life especially
• mild: scouring, sickness
• severe: toxemia, lameness, diarhea

Question 28

genus: enterobacter

Answer 28

• lactose fermenter, non-hemolytic
• cause opportunistic infections in immunocompromised hosts
• mastitis, uterine infections (horses), bacterimia (humans)

Question 29

genus: klebsiella

Answer 29

• lactose fermenter, non-hemolytic
• opportunistic pathogen
• capsule
• mastitis (cow), cervicitis and metritis (mares), UTIs, pneumonia (humans), cystitis (dogs)

Question 30

genus: proteus

Answer 30

• lactose non-fermenter
• four species
• motile, non-hemolytic
• concentric rings on plate
• UTIs in dogs and cats
• not an enteric pathogen in animals

Question 31

genus: providencia

Answer 31

• lactose non-fermenter
• rarely cause animal infections, not an enteric pathogen
• diarrhea in humans

Question 32

genus: morganella

Answer 32

• lactose non-fermenter
• opportunistic pathogen
• intestinal tract of humans and animals
• not an enteric pathogen
• isolated from wound and UTIs

Question 33

genus: shigella

Answer 33

• affects only humans and non-human primates

- dysentery