Rapid diagnosis of microbial diseases
Equine
1- Strangles, specimens, pus smear’s from sub maxillary
lymph node or pus stain gram strain.
Causative agent . Streptococcus equi microscopical
examination .Presence of long chain of gram-positive cocci
after gram staining of pus smears.
2- Glanders: no method for rapid diagnosis within short time
(1-2 hours) causative agent pseudomonas mallei ( burkh
olderia).
Methods for diagnosis
 Mallein test (farm).
 Culture of pus from nodule or ulcers on selective
media or blood agar.
Results obtained within few days.
 Complement fixation test (serology).
3- Epizoatic lymphangitis :
Specimens Pus taken from unopened lymphatic nodules by
syringe or using cotton swabs for ulcers and opened lymphatic
nodules which present usually on (alongside) lymphatic vessels
of neck parallel to jugular vein in the neck region.
Staining : gram stain or giemza stain.
Causative agent: Histoplasma farciminosum microscopical
examination.
Staining of pus smears showed the yeast phase in form of
double yeast or tetrad , lemon pear or oval shape yeast
surrounded by white hallow capsule unstained present extra
cellular or intra cellular.
Rapid diagnosis equine
4- Ulcerative lymphangitis
Specimens pus taken by syringes from pectoral abscesses
large well encapsulated odor free tan purulent exudate
and also from other regions sites tri cops muscle limbs
prepuce mammary gland axilla & ventral mid line abdorer.
Stain and causative agent: gram stain, Corynebactium,
Pseudotuberculosis microscopical examination. Pus &
exudate smear showed gram-positive bacilli, pleomorphic
palisade arrangement.
5- Sporotrichosis is a chronic lymphocutancous infection of
horse caused by Sporothrix Schenckii, dimorphic gungs
yeast phase in body and my celial phase in soil.
Specimens, pus or exudate from distal lamb neck face can also
be affected taken from firm cutaneous nodules (0.5 cm
diameter) no painful lesion enlarge slowly and ulcerate and
discharge creamy brown to yellow purulent discharge the
infection localized or spread along lymphatic vessels of legs.
Staining gram stain of pus or exudate characteristic shape cigar
shape yeast + pleomorphic oval shape gram.
Rapid diagnosis of microbial diseases
I. Bovine
II. Brucellosis
I.Bovine
Specimens. Milk, vaginal smears, aborted foetus
placenta blood for serology after 2 weeks of abortion
(mention four microorganism causing abortion)
causative agent, brucella abortus , B.melitensis.
1- Preparation of smears.
Smears from abomasum content and also in press smears from
cotyledons of placenta stained by ziehl- nelsen stain or gram
stain showed gram negative (red) small coccobacilli in clumps
usually because of intracellular growth.
2- Serology (rapid).
After separation of serum from blood (7c.c) Rose Bengal Plate
test is used as antigen for rapid screening of the disease (one
drop serum + one drop RB antigen mix 4 minutes rotating
movement presence of agglutination particles indicate positive
result, negative result usually not subjected to other
serological tests.
(Mention four serological tests (slowly tests) used).
3- Milk ring- test
1 ml of milk ( taken from incubated milk for 18 hours)+ drop of
colored (blue) antigen put in small test tube incubated for 1-3
hours
presence of blue ring at the upper surface of milk
suggest the positive result (mastitis and the first week of
calving give false positive).
II.Bovine
Chlamydia & Cambylobacter, specimens . Placenta
impression smears from cotylcdon and stained with
giemsa.
Campylobacter facts
Specimens. Exudate (abomasum content taken by
syringe, make smears and stain with gram stain, gram
negative curved , comma-shaped, s .shape , helical shaped
pink in color had been demon started in abomasum
content of the facts.
III. Bovine tuberculosis
Living animal 1- nasal discharge 2- 15 ml of milk.
Dead animal
groups of lymph node sub maxillary,
retropharyngel, bronchial, thorax mesenteric, supra mammary
lymph glands.
Rapid diagnosis
- Milk samples
(A) Centrifugation of 15 ml of milk (last strips)3000 rpm, for
10 minutes and make milk smear from upper fat layer
and from the sediment, dry in air and fix the smear on
benzene burner after that stain with ziehl neelsen stain
to and examined the slide microscopically for
demonstration of acid fast bacilli single short thick
bacillior clump (group) of bacilli, red in color.
(B) Large lymph gland cut by knife (showed caseated thick
pus) make impression smears from the cut- surface
stain with Zieh-Neelsen stain and examined
microscopically.
(Question: mention abort PPD and comparative skin test).
Rapid diagnosis of bovine diseases (Bacillus Anthracis )
4- Anthrax
Specimens.(1) amblical-tap of gauze inside sterile test tube,
sincked with venue blood and left to dry in air put inside the
tube and send it to the laboratory for culture.(2) cotton swab
take one drop of blood dry in air and send.
(3) Blood smear
 Send dry blood smear from venous blood dry in air and
send it to the laboratory.
 fix with methanol (3 minutes) and stain with giemza or
with 1% loefflers methylene blue for 5 minutes wash , dry
and examine under oil immersion lenses.
 Demonstration of pinkish capsule which surround the
thick bacilli (2-3 bacilli) blue color cut- ended. Move the
fine adjustment to demonstrate the pinkish capsule.
5- Actinomycosis and actinobacillosis specimens
Pus from mandible region is collected by cotton swabs or
syringe from the edges of lesions or the opening which
discharge the pus. Causative agents , actinomy bovis gram.
Positive bacilli Actinobacilli legniersei gram negative bacilli
causing wooden tongue rapid diagnosis.(1) making pus smears
stain with gram for demonstration of gram positive bacilli.(2)
small amount of pus (1-2 cc) is placed in petri dish and washed
with water for exposing isolation of small sulphur granule the
granules are transferred to a slide and a drop of 10% NaOH is
added, put a cover slip on granules crush by pressure and
examined under low power for club shaped.
Rapid diagnosis of bovine diseases
6- Nocardiosis
N. asteroids cause acute and chronic granulomatous mastitis in
cattle, characterized by suppurating granulomatous lesions
discharge the pus on the external surface of udder with
presence of draining tracts with fistulas generalized no
cardioids characterized by pneumonia and accumulation of
fluid in thoracic and low abdomen cavity.
Direct examination
Gramm stained smears of pus or crushed granules revel gram
positive branching filaments roods with or without club these
filaments are partially acid fast with ziehl - Neelsen stain.
7- Pasteurellosis (P.multocida)
A. Pneumonic Pasteurellosis living animal , odematous fluid
nasal swabs dead animal , lung (freeze and send under
refrigeration.
B. Septicacmic- form (Pneumonic living animal nasal disd.
Living animal , 5 ml of blood send under refrigeration & should
arrive to the laboratory within 15 minute or 2 ml with
anticoagulant, blood smears.
Direct examination 1- impression smears from lungs 2- blood
smears (septicacnicfom)
Stain after fixation with 1% loefflers methylene blue for 5
minute and examine under oil immersion bipolar
microorganisms , bipolar coccobacilli.
8- Bovine theileriasis
Causative agents
Theileria annulata and Theileria parva specimens
1. Blood smears from jugular vein.
2. Lymph smears from prescapular lymph node.
Methods for diagnosis stain with giemza


Blood smear shows ring shape theileria inside red blood
cells.
Lymph smears stain with giemza or leishmans shows
both macroschizont and macroschizont (both are called
Koch’s blue bodies of blue or red color) situated intra
cellular inside macrophages or extra cellular (in
babesia, take smears from ear vein).
9- John’s disease
Causative agent.
Mycobacterium paratuberculosis , acid fast red specimens
taken from mucous membrane of rectum usually corrugated or
from mucous membrane mixed with faces this happen usually
at the later stages of disease were there are sloughing of
mucous membrane.
Direct examination of m.m of rectum makes smear from m.m
and stain with acid fast stain ziehl-Neelsen demonstration of
pinkish acid fast bacilli nest- like groups. Thick short rods in
group nest like.
Serological diagnosis (1) johnin test (2) elisn test.
1- Penicillin group G
Benzyl penicillin, benzathin penicillin (narrow spect ) penicillins
group M , methicillin oxacilian
Penicillins group A , ampicillin amoxicillin broad.
Antipseudomonas
,penicillin
piperacillin mezlocillin , azlocillin.
carbenicillin
,
ticarcillin
2- Aminoglycosides
Gentamicin , tobramycin , amikacin netilmicin , streptomycin ,
neomycin.
3- Cephalosporin (cidal)
Cephalothine, cephalosporin and cephaloridin, cefoxitin ,
cefotetan cephamandole , cefuroxime,
Cefotaxime , ceftriaxone , ceftazidime.
4- Tetracycline (broad)
Doxycycline oxytetracycline.
5- Static macrolides
Erythomyan , tincomycin clindamycin