1. GRAM
+ve
Bacteria:
BACILLI
SPORE
FORMERS
NON-­‐SPORE
FORMERS
BACTERIA
Clostridium
Bacillis
Listeria
Erysipelothrix
Corynebacterium
Rhodoccus
:o
C.botulinum
**B.anthracis
L.monocytogenes
E.rhusiophathiae
C.diphtheriae
C.pseudoTB
R.equi
PATHOGENISIS
Blood
to
PNS;
Blocks
release
of
Ach;
Flaccid
paralysis
and
death
kills
phagocytic
cells;
inc
cap
perm;
interfere
clotting
cascade
Ruminants:
Meningoencephalitis
Listereosis:
Zoonosis
Intracellular:
Penetrating
epi
cells;
grow
Survives
in
macrophages
Serotypes
1a,
1b,
2
Erysipalis
Swelling
of
capillary/venule
endothelial
cells
and
thrombus
formation
Only
when
infected
w/temperate
phage
(bacterial
virus)
which
encodes
toxin
Caseous
lymphadenitis
(cheeeeese)
Chronic
suppurative
bronchopneumonia
in
foal;
associated
w/underdevo
cell-­‐med
im
(=
adults
immune)
Large
pulmonary
abscesses
in
lungs
TOXIN
Exotoxins
A-­‐H
Holotoxin
Lysteriolysin
to
escape
phagosome;
contents
=
host
cell
damage
=
Antibody
ineffective
=
cell-­‐med
im
resp
Neurominodase?
Diphtheria
toxin
(not
known
to
cause
disease
in
animals)
Phospholypase
toxin
SPREAD
Bloodstream
Spiny/irritating
vegetation
allows
spores
access
tissue.
Lymphatics
to
bloodstream
Reside
in
safe
cytoplasm
Neutrophils
can
kill
when
in
extracellular
env
Systemic
Lymphoid
tissues
Penetrate;
access
to
bloodstream;
Joints
&
Heart
valves
Skin
and
mucous
membranes
Carried
on
skin
of
sheep
CHARACTERISTI
CS/STERILISATI
ON
Resistant
to
boiling.
Heat-­‐liable
(20min
100C):
Cook
Capsule
Autoclaving
(200ppm
hypochlorite)
Dry
heating
(160C
2h)
Live
spore
Sterne
vaccine
Antitoxin
Survive
pH
4.0
Can
grow
in
low
temp
(<10C)
Surface
capsule
Non-­‐motile
Adjuvanted,
killed
serotypes
1&2
and
live
vaccines:
Pigs
Small,
tough,
innocuous
“Diptheroids”
Facultative
intracellular
(survive
in
m’s!)
Similar
to
Coryneacterium!
Is
seen
as
short
rods!
Persist
in
manure-­‐
contaminated
soil
for
years.
TRANSMISSION
Spores
germinate
in
anaerobic
soil
and
sewage
(Saprophytes)
–
enter
G.I.T
by
ingestion.
Saprophytes
in
environment;
silage
Shed
intermittently
in
faeces
and
milk
esp.
after
stress
Carriers
shed
in
env
Enter
oral/resp
route/break
in
skin
Sheering
wounds
Naturally
found
in
soil
and
intestines
of
horses
DIAGNOSIS
**Sensitive
to
Penicillin
G
MacFadyean’s
reaction:
Stains
purple
w/Polychrome
methylene
blue;
Bacilli
appear
as
chains
of
dark
blue,
square
ended
rods;
encapsulated.
Before
P.M
or
moving
carcass;
Notifiable
disease
Haemolytic
on
blood
agar
(listeriolysin)
Grows
on
blood
agar
α-­‐haemolytic
Coagulase
(usually)
Catalase
-­‐ve
Salmon-­‐pink
pigment

2. GRAM
+ve
Bacteria:
BACILLI
Arcanobacterium
Acintomyces
Nocardia
Mycobacterium
A.pyrogens
A.viscosus
A.bovis
N.asteroides
M.bovis
*Badgers
&
Cattle
Other
Abscesses
(liver)
Summer
mastitis
Ovine
foot
disease
Pyolysin:
cytotoxic
for
phagocytic
cells
Actinomycosi
s
in
dogs
Localised
granulomato
us
abscess
of
skin/thoracic
lesion
Lumpy
jaw
in
cattle
Granulomatous
lesions
of
soft
tissues
and
bone
Granulomatous
lesions;
able
to
survive
and
grow
in
macrophages
Chronic
-­‐>
fatal
Pneumonia
&
wasting
Disease
beings
in
lesion
elsewhere
in
body;
slow
multiplication;
phagocytosis;
inhib
phagosome-­‐lys
fusion
Sensitisation
via
lymphocyte
recognition;
infectious
granuloma
(tubercle)
M.xenopi:
Cold-­‐blooded
M.avian:
Common
in
pigs
at
slaughter
Poultry
(wild
birds
and
free
range)
Deer:
common.
M.bovis
inc
[Horses:
Naturally
resistant;
rare]
[Dogs:
M.tuberculosis
from
humans]
[Sheep/Goats:
V.rare]
Several
extracellular
pore-­‐forming
toxins
If
infection
not
destroyed
by
CMI
of
granuloma;
release
bacilli;
tubercles
in
other
tissues
and
organs
Upper
resp
tract
and
genital
tracts
of
domestic
animals
Ruminal
wall
May
progress
into
abdomen
(pyothorax)
Lesions
more
difficult
to
treat
than
acintom.
As
resistant
to
number
of
antimicrobials
Cattle
>6months:
Respiratory
route
via
Alimentary
tract
(post-­‐natal,
calf
infection)
and
congenital
route.
Adult:
After
resp
infection
as
tuberculosis
bronchiolitis;
bronchiolar
spread;
TB
pneumonia;
Caseous
liquefaction
&
bronchiectasis;
open
case
Similar
to
Coryneacteriu:
Chinese
characteristics
in
W,
N,
M
arrangement
Curved/swollen
ends
Filamentous;
branching
Prefers
anaerobic
but
not
strict
anaerobe
Forms
branching
rods
much
shorter
than
actinomycetes
[Isolation
PM:
inject
material
into
guinipig
(v.susceptible):
act
as
a
biological
filter;
succumb
to
disease
if
M.bovis
present
–
now
discontinued]
Relatively
resistant
to
drying
(viable
for
yrs),
antibiotics
and
chemical
agents:
common
to
pre-­‐
treat
specimens
w/NaOH/Oxalic
acid
to
destroy
normal
bacteria
leaving
mycobacteria
unharmed
Round-­‐ended
rods
Strict
anaerobes
Slow
growing
Some
saprophytic
will
grow
in
colonies
in
few
days
but
pathogenic
take
2-­‐8
weeks
Opportunistic
pathogen
Soft
grey
granules:
when
squashed,
organism
released
Oral
bacteria;
inoculated
into
tissues
by
trauma
Soil
bacterium
Shedding
into
env
–
lesion
excretion;
‘open
case’:
udder/uterus/resp
tract;
coughing
Immunity
does
develop
but
inadequate
Grows
slowly
on
blood
agar:
small
white
colonies
surrounded
by
zone
of
β-­‐haemolysis
after
48
hours.
Non-­‐acid
fast
Catalase
+ve
Partially
acid-­‐fast;
cell
walls
contain
mycolic
acids
(like
mycobacteria)
Mycolic
acid
repels
aq
stain
Although
G+ve
in
cell
wall
structure,
are
difficult
to
stain;
Acid
fast
Zeihl-­‐Neelsen
stain
used
instead.
TESTS:
Single,
comparative
intradermal
test
of
PPD
–
TCA
precipitated
tuberculin.
M.bovis
and
M.avian
–
both
injected
intradermally
–
exam
after
72h
[Cattle
susceptible
to
M.avian
(localised
lesions);
PPD
w/M.avian
would
cause
sensitisation
alone]
CMI
response!
=
Swelling
+
Oedema
=
+ve
(Type
IV
reaction)
No
Vac
as
interfere
w/test.
IF-­‐γ
stimulation
test:
Collect
blood;
culture
lymphocytes;
stimulate
w/PPD
ELISA
(useless
as
v.little/no
antibody!):
Measure
release
of
IF-­‐γ
PCR/Immunofluorescence
–
look
for
bacteria

3. GRAM
+ve
Bacteria:
BACILLI