Klebsiella species are common bacteria found in the environment and in humans as normal flora. However, they can act as opportunistic pathogens, causing infections like pneumonia, urinary tract infections, and rhinoscleroma. Diagnosis involves Gram staining, culturing samples on selective media, and biochemical testing to identify the species and determine if it is causing an infection.

1. KLEBSIELLA
• Klebsiella species are found everywhere in nature.
They have associated biochemical adaptations
which make them better suited to a particular
environment. They can be found in water, soil,
plants, insects, animals, and humans
• Klebsiella species are routinely found in the human
nose, mouth, and gastrointestinal tract as normal
flora; however, they can also behave as
opportunistic human pathogens. Klebsiella species
are known to also infect a variety of other animals.

2. Type of klebsiela and disease
associated
• K. pneumomia: causes lobar
pneumonia(Lobar pneumonia is an acute
exudative inflammation of an entire
pulmonary lobe) & UTI(Urinary Tract Infection)
which mainly nosocomial(present in hospital)
• K. rhinoscleromatis: causes
rhinoscleroma(granuloma of nose and throat)

3. • K. oxytoca : nosocomial infection.( colitis and
sepsis)
• K. ozonae : causes atrophic rhinitis.( decrease
in size of mucuous lining surface)

4. Diagnosis of klebsiella infection
• Sample: site of infection (sputum)
Procedure:
1. Gram stained smear: Gram (-) bacilli, non-motile, polysaccharide capsule (K
antigen), oxidase negative, rod shaped bacilli
2. Culture:
 on Mackoney’s agar plate: rose pink colonies due to lactose fermentation
 On EMB(eosin methylene blue) agar plate: large, mucoid colonies due to
production of extracellular slime
3. Biochemical reaction:
 Ferment glucose, lactose, maltose, mannite, sucrose with production acid
and gas
 TSI(triple sugar iron) medium: yellow(acidic) butt and yellow(acidic) slant
 IMVC(4 different tests that are used for differentiation of enteric bacteria)
test:
 Oxidase and 𝐻2
S negative, variable urease result and reduce nitrate to
nitrite.

5. • 4. serology: antigen can be detected by slide
aggluttination test and capsular swelling test

6. Lobar pneumonia& Rhinoscleroma