medical Microiology

1. Klebsiella
School of Medical Laboratory
Sciences
Department of Microbiology
Medical Bacteriology course
Dr.Mahadi Hassan Mahmoud
PhD Microbiology

2. Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gamma
Proteobacteria
Order: Enterobacteriales
Family: Enterobacteriaceae
Genus: Klebsiella
Species: K. pneumoniae

3. History
 The Danish scientist Hans Christian Gram
(1853–1938), developed the technique
now known as Gram staining in 1884 to
discriminate between K. pneumoniae and
Streptococcus pneumoniae.
 Klebsiella was named after the German
bacteriologist Edwin Klebs (1834–1913).
 Community-acquired pneumonia caused
by Klebsiella pneumoniae may be called
Friedländer's Pneumonia, after Carl
Friedländer

4. Klebsiella:
 Member of enterobacteriaceae.
 Mainly saprophyte (water, soil and
vegetation).
 Gram negative rods.
 Non-sporing.
 Capsulated.
 Non-motile.

5. Klebsiella:
 The most important species in medical:
– K. pneumoniae.
– K. aerogenes.
– K. oxytoca.
– K. rhinoscleromatus.

6. Morphology & stain:
 Gram negative bacilli, thick and short.

7. Cultural characters:
 Facultative anaerobe.
 Non-fastidious.
 Optimum temperture 37C0.
 On MacConkey agar: Pink colonies (LF),
large mucoid colonies, moist and high
convex.
 On CLED: Yellow colonies (LF), large
mucoid colonies, moist and high convex.

8. Cultural characters:
 On Blood agar: Non-haemolytic colonies,
large mucoid colonies, moist and high
convex.

10. Biochemical reaction:
 Indole test: -ve.
 Urease test: +ve.
 Citrate utilization test: +ve.
 Motility test: -ve.
 Ferment glucose & lactose with production of
acid/gas.
 Does not produce H2S.
 MR test: +/-ve. (according to species)
 VP test: -/+ve. (according to species)

11. 

12. Antigenic structure:
 Possess O & K antigens.
 According to K antigen serotyped to 80
serotype.

13. Viability:
 Mainly found in water and soil.
 Resist to ampicillin.

14. Pathogenicity:
 Opportunistic pathogen.
 Mainly cause:
– Urinary tract infection (UTI).
– Wound infection.
– Pneumonia.
– Septicaemia (as a complication of many
infection).

15. Lab-diagnosis:
 Specimen: according to the side of infection (Urine,
pus , sputum or blood).
 Direct Gram stain:(Non contaminate specimen).
 Culture media: CLED, Blood agar and MacConkey
agar.
 Incubation.
 Colonial morphology.
 Biochemical reaction.

16. Atibiogram
 Klebsiellae often produce beta-
lactamases and are
resistant to ampicillin.
Cephalosporins and aminoglycosides
are used to treat Klebsiella infections.
 Some Klebsiella strains show multiple
drug resistance.

17. Enterobacter species
 Enterobacter organisms can be found in
the intestinal tract of humans and animals,
and in soil, sewage, water, and dairy
products.
They are opportunistic pathogens,associated
with urinary infections, wound infections,
and septicaemia,especially in persons
already in poor health.

18.  Enterobacter species are Gram negative
motile rods.
 On blood agar, they produce large
colonies that may resemble those
produced by klebsiellae but not so mucoid.