1. 4/15/2013
1
Sharq Elneil College
School of Medical Laboratory Sciences
Department of Microbiology
Medical Bacteriology course
Mr.Mahadi Hassan Mahmoud
Bsc, Msc, MIBMS Microbiology
08 April 2014
genus yersinia includes
 yersinia pestis, the cause of
plauge
 y.pseudotuberculosis
 y.enterocolitica, important
causes of diarrhoeal disease

2. 4/15/2013
2
 francisella tularensis
occasionally causes septic
infections.
 several species of pasteurlla are
primarily animal pathogens but
also causes human disease.
 Gram-negative rod short, pleomorphic
 Intracellular pathogen
 Zoonotic infection
 exhibit bipolar staining.
 they are catalase positive,
 oxidase negative,
 microaerophilic or facultative anaerobic.

3. 4/15/2013
3
 World-wide problem
 India has had latest scare (100s
infected)
 Sporadic cases in the U.S., south-
western mostly
 Usually associated with contact with
squirrels and other urban animals

4. 4/15/2013
4
Flea bite
Bacilli travel to lymph nodes
Infection results in swelling
and pain (Bubo seen in picture
below)
High fever, chills, headache,
nausea

5. 4/15/2013
5
 Clinical Syndromes
(Septicemic Plague)
Can penetrate and invade
bloodstream
 All organs infected
 Lungs (secondary pneumonic
plague)
 Danger to close contacts
 Clinical Syndromes (Primary
Pneumonic Plague)
 Spread via respiratory droplets
 1 bacilli can cause disease in patient
 Severe hemorrhaging
 Death in hours
 100% mortality if untreated, or late
treatment

6. 4/15/2013
6
50-75% mortality when it goes to
bloodstream
 Endotoxin shock primary problem
Intravascular coagulation
Multi-organ failure
“bruising” on skin……this is how
it got the name the ”black death”
See the same thing with Neisseria
meningitidis
Yersinia pestis and plauge
Plauge is an infection of wild
rodents, rodents, rodents,
transmitted from one rodent to
another and occasionally from
rodent to human by the bites of
fleas (black death).

7. 4/15/2013
7
I. Bubonic Plague:
 Interhuman Transmission:
> Bubonic Disease >Pneumonic
Plague > Exhales the Organism in
Droplets.
 Pestis Minor:
ii. Septicaemic Plague:
iii. Pneumonic Plague:
Symptoms
After i.p of 2-7days,there is high fever
and painful lymphadenopathy,
common with greatly enlarged, tender
nodes (buboes) in the groin of axillae.
vomiting and diarrhoea may occur with
early sepsis. later D.I.C. lead to
hypotension, renal and cardiac failure.
y. p, multiplies intravascular and can be
seen in B. smears.

8. 4/15/2013
8
Specimens:
 Blood is taken for culture
 Aspirates of enlarged lymph nodes
for smear and culture.
 Acute and convalescent sera may be
Examined for antibody level
 Pneumonia sputum is cultured,
 Meningitis C.S.F is taken for smear
and culture.
 Stained with giemsa
 waysons
 I.F stain.

9. 4/15/2013
9
Culture: all materials are cultured on
 B.A
 MaCconkey
 infusion broth.
on solid media growth is slow but b.
cultures are often positive in 24hrs.
Serology:

10. 4/15/2013
10
Sensetive to
 streptomycin.
 Tetracycline
 some times given in
combination.

11. 4/15/2013
11
A Quarantinable Disease.
 Control of Urban Plague:
 Garbage Disposal.
Y. enterocolitica and Y. pseudotuberculosis
 These are non lactose fermenting
 G-ve rods that are Urase+ and Oxid-
.They grow best at 25 cand also
motile, but not motile at37c,
 Diagnostic tests:
 Specimen, culture, serology.
 Treatment: most yersiniae infections
with diarrheal are self limited.

12. 4/15/2013
12
Francisella Tularensis and
Tularemia
 F.Tularences, is widely found in animal
reservoirs and transmitted to human by
biting arthropods, inhalation or ingestion
of contaminated water or food.
Morphology and identification
 F.T, is small G-ve pleomorphic rods, it
rarely seen in smears of tissue.
Specimen: blood is taken for serologic tests.
Culture:
 growth does not occur in most
ordinary media
 small colonies appear in 1-3 days on
glucose cysteine B.A incubated 37c
under aerobic condition.
 the organism identified usually by its
growth requirement and I.F stain.
 Caution: the organism is highly
infectious.

13. 4/15/2013
13
Serology:
 there is one or more AG can cross
react with brucella.
Diagnostic tests:
 generally smears and cultures are
not contributory
 diagnostic tests rests on serology,
paired serum collected 2 weeks
apart can show arise in titer, titer of
1:60 is highly suggestive.
Antibiogram
Sensetive to:
 Streptomycin
 Gentamicin
 Tetracycline equally effective, but
relapses occur morely frequently.
 Ceftriaxone is not effective.

14. 4/15/2013
14
 These are primarily animal pathogens
 non motile
 G-ve coco bacilli
 They are aerobe and facultative
anaerobe they are grow in ordinary
media at 37c .they are O+ve, Cat+ve.
Pathology
 The most common presentation is a history
of animal bite followed by an acute onset
of redness, swelling and pain, fever is often
low grade, lymphadenopathy is variable.
infections some times present as
bacteremia or chronic respiratory infection
without an evident connection with
animals.

15. 4/15/2013
15
species routine
nutri-
ent
media
bile
salt
media
Motil
ity
At 22c
At
37 c
Acid
(no gas)
from
maltose
sucrose
y. pestis + + - -- + -
y. pseudo-
tuberculosis
+ + + - + -
y. enterocolitica + + + - +b +
p. multocida + - - - - +
F tularensis - - - - + -
species slicin indol
e
urea
se
oxidas
e
cat onpg Orithine
decarbo
xylase
Y. pestis + - - - + + -
Y. pseudo
tuberculosis
+ - + - + + -
Y. enterocolitica - - + - + + +
P. multocida - + - -/+ + - +
P. ureae - - + + + - +
F. tularensis … - - … +/- …. -

16. 4/15/2013
16
THANK YOU FOR ATTENTION