Gram positive bacilli

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%cellQmed%im%
(=%adults%immune)%
Large%pulmonary%
abscesses%in%lungs%
TOXIN!Exotoxins+A=H(Holotoxin(Lysteriolysin%to%escape%
phagosome;%contents%=%
host%cell%damage%=%
Antibody%ineffective%=%
cellQmed%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%
NonQmotile%
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%manureQ
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%
αQhaemolytic%
Coagulase%(usually)%
Catalase%Qve%
%
% SalmonQpink%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%Q>%fatal%
Pneumonia%&%wasting%%
Disease%beings%in%lesion%elsewhere%in%body;%
slow%multiplication;%phagocytosis;%inhib%
phagosomeQlys%fusion%
Sensitisation%via%lymphocyte%recognition;%
infectious%granuloma%(tubercle)%
M.xenopi:(%ColdQblooded%
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%
poreQforming%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%(postQnatal,%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%preQ
treat%specimens%w/NaOH/Oxalic%acid%to%destroy%normal%bacteria%leaving%mycobacteria%
unharmed%
RoundQended%rods%
Strict%anaerobes%
Slow%growing%%
Some%saprophytic%will%grow%in%colonies%in%few%days%but%pathogenic%take%2Q8%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%βQhaemolysis%after%
48%hours.%
NonQacid%fast%
Catalase%+ve%
Partially%acidQfast;%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%
ZeihlQNeelsen%
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%IFQγ!
PCR/Immunofluorescence!–%look%for%bacteria%

3. GRAM%+ve%Bacteria:%BACILLI%
%