bacteriology 11

Question 1

bordetella

Answer 1

gram negative, short rods
obligate aerobes
oxidase positive
motile
grows on macconkey and blood

Question 2

bordetella species of veterinary importance

Answer 2

bordetella bronchispetica

Question 3

where is bordetella found

Answer 3

obligate parasite of ciliated respiratory epithelium
maintained in carrier animals not nf
couching are the main source of infection for naive dogs

Question 4

how is bordetella transmitted

Answer 4

inhalation
contagious
large outbreaks

Question 5

how does bordetlla cause disease

Answer 5

adapted to set up conditions that allow colonization and disease of repiratory tract
can predispose to more serious disease

Question 6

specific diseases does bordetlla cause

Answer 6

canine infectious tracheobronchitis-canine cough, kennel cough
tracheobronchitis/pneumonia
atrophic rhinitis-pigs

Question 7

canine cough/kennel cough

Answer 7

dry hacking that may be productive or non productive
can be exacerbated by exercise, excitement or pressure of the collar
can also be elicited by tracheal palpation
gagging, retching or nasal discharge
not usually show signs of systemic illness
can cause initial damage and allow secondary invasion by other bacteria that may enter the LRT

Question 8

tracheobronchitis and or pneumonia

Answer 8

wide range of animals
dogs, cats, horse, rodents, people
usually involves other bacteria or virues
secondary invader that causes serious dz

Question 9

atrophic rhinitis

Answer 9

pigs
sows are carrier
invades initially

Question 10

diagnose bordetella

Answer 10

canine cough-presumptive diagnosis
tracheobronchitis/pneumonia-not part of normal flora of URT, no nasopharyngeal swabs may be ok, samples can be cultured or multiplex PCR and collect samples from LRT
atrophic rhinitis-clinical signs and lesions usually sufficient
swabs of the nasopharynx and culture for isolation

Question 11

treat bordetella

Answer 11

self limiting infection and may resolve on own
antibiotic therapy may reduce length of time of coughing and help prevent secondary complication
treat if suspect bronchopneumonia
not predictably susceptible so should do culture and susceptibility testing if-animals not responding, dogs are very ill or if cat is involved

Question 12

pseudomonas

Answer 12

gram negative rods
obligate aerobes
highly motile
metallic sheen and smell fruity
oxidase positive

Question 13

only veterinary species of importance

Answer 13

pseudomonas aeruginosa
isolation of any other pseudomonas spp arise from contamination

Question 14

where do you find pseudonmonas

Answer 14

ubiquitous
saprophyte-live in soil and water
transitorily-in feces, skin and mucus membranes or normal animals
can survive in weird places

Question 15

pseudomonas virulence factors

Answer 15

pili-adherence to host cells
exotoxin-kill cells especially phagocytes
endotoxin
pyocyanins and fluoroscein-kills cells and damage tissue and causes green coloration of colonies
collagenase, elastase-breaks down collagen and damages blood vessels
biofilm production-aids in coloization, resist phagocytosis and antimicrobial tolerance

Question 16

pathogenesis of pseudomonas

Answer 16

environmental exposure is constant
infections are secondary to compromised host tissue-need underlying injury or damage to get disease
opportunistic pathogen but needs significant host compromise to cause disease

Question 17

steps in superintection

Answer 17

first some underlying disease/predisposing factor causes tissue damage
this will disrupt the normal flora and allow other good pathogens to cause infection
the bacterial infection is diagnosed and treated with antimicrobial therapy which may kill the first bacteri
but underlying disease not addressed in therapy so still have compromised/damaged tissue

Question 18

what bacteria cause super infection

Answer 18

pseudomonas aeruginosa
nocardia spp
klebsiella pneumoniae
bacillus cereus
enterococcus
there are a number of bacteria which may be involved in superinfection which have a similar pathogensis

Question 19

key points to superinfection

Answer 19

unless the underlying factor allowing disease to occur is resolved you will not resolve the superinfection
need to treat/cure the underlying process and treat the bacteria causing the superinfection by doing a susceptibility test as they are usually very resistant

Question 20

opportunistic infection-pseudomonas aeruginosa

Answer 20

corneal ulcers (keratitis)-many animal species
dermatitis(green wool)-sheep-skin infection with wet conditions
wound infection-all species, especially burn wounds, love moist environments and burn wounds have a lot of exudation

Question 21

superinfections-pseudomonas aeruginosa

Answer 21

can be involved in superinfections in all situation
there are some other situations where P aeruginosa may be involved

Question 22

infection-pseudomonas aeruginosa

Answer 22

compromised host or susceptible species
abscesses/pneumonia/septicemia
infectious stomatitis

Question 23

how to diagnose pseudomonas aeruginosa

Answer 23

frequently a contamination during sample collection
isolation alone does not necessarily mean that it is significant
careful: review of history and clinical signs
application of the appropriate rule for interpretation
repeat isolation if uncertain

Question 24

treat pseudomonas aeruginosa

Answer 24

with difficulty
often respond poorly to antimicrobial therapy
intrinsic antimicrobial resistance
acquired resistance in some strains
therefore must do susceptibility testing and use appropriate antibiotics
underlying host compromise also important
very important to address host factors if you will for resolution of disease-diagnose and treat underlying disease, getting rid of necrotic tissue, and drying out-remove excess exudation