K. granulomatis doesn't grow in bacteriological media.
K. africana is biochemically similar to K. pneumoniae complex members and can be differentiated by the inability to metabolize
D-arabitol.
K. grimontii is distinguishable from K. oxytoca and K. michiganensis by the inability of most strains to ferment melezitose.
K. michiganesis is distinguishable from K. oxytoca by no urease production, no utilization of putrescine, and no pectate degradation.
K. quasipneumoniae is difficult to be differentiated from K. pneumoniae using biochemical tests. K. quasipneumoniae can utilize
tricarballylic acid and may ferment L-sorbose.
K. pasteurii is negative for lysine decarboxylation.
K.
spallanzanii is negative for Voges-Proskauer test and unable to use L-proline.
K. variicola - can only be genetically differentiated from K. pneumoniae strains; does not ferment adonitol.
Genus Klebsiella
Klebsiella pneumoniae cells, Gram staining
Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Proteobacteria, Class Gammaproteobacteria, Order Enterobacterales, Family Enterobacteriaceae, Genus Klebsiella,
-
Klebsiella aerogenes (Hormaeche and Edwards 1960) Tindall et al. 2017 (old synonyms: Enterobacter aerogenes Hormaeche and
Edwards 1960,
K. mobilis Bascomb et al. 1971);
- Klebsiella africana corrig. Rodrigues et al. 2019;
- Klebsiella granulomatis Carter et al. 1999, basonym: Calymmatobacterium granulomatis Aragao and Vianna 1913, old synonyms:
Encapsulatus inguinalis Bergey et al. 1923, Klebsiella granulomatis Bergey et al. 1925, Donovania granulomatis Anderson et al. 1944;
- Klebsiella grimontii Passet and Brisse 2018 (previous Klebsiella oxytoca phylogroups Ko2 and Ko6);
-
Klebsiella huaxiensis Hu et al. 2019;
-
Klebsiella indica Gujarati et al. 2020;
-
Klebsiella michiganensis Saha et al. 2013;
- Klebsiella oxytoca Lautrop 1956, (Bacillus oxytocus perniciosus Flügge 1886);
-
Klebsiella pasteurii Merla et al. 2020;
- Klebsiella pneumoniae subsp. pneumoniae Trevisan 1887 (Bacillus pneumoniae Schroeter 1886) - type species of the genus;
- Klebsiella pneumoniae subsp. ozaenae Orskov 1984 (Bacterium ozanae, Abel 1893);
- Klebsiella pneumoniae subsp. rhinoscleromatis Orskov 1984 (Trevisan 1887);
- Klebsiella quasipneumoniae Brisse et al. 2014;
- Klebsiella singaporensis Li et al. 2004;
-
Klebsiella spallanzanii Merla et al. 2020;
- Klebsiella variicola subsp. variicola (Rosenblueth et al. 2004) Rodrigues et al. 2019;
- Klebsiella variicola subsp. tropica
corrig. Rodrigues et al. 2019.

NOTES
K. singaporensis is a later heterotypic synonym of Klebsiella variicola Rosenblueth et al. 2004.
K. planticola, K. ornithinolytica and K. terrigena, were transferred to genus Raoultella.
K. aerogenes (Hormaeche and Edwards 1960) Tindall et al. 2017 and K. mobilis Bascomb et al. 1971 are later synonyms of
Enterobacter aerogenes
.
Gram-negative, straight, non-motile, capsulated, 0.3-1.0 μm x 0.6-6 μm bacilli.
K. oxytoca strains produce a dark brown pigment when growth on media containing
gluconate and ferric citrate.
Glistening moist colonies of varying degrees of stikiness (M–type colonies). Klebsiella
granulomatis
grows intracellulaly only; it has not been cultured.
No special requirements. Facultatively anaerobic, optimum growth temperature 35-37
ºC. Grows on: Nutrient agar/broth, Trypticase Soy Agar ± 5% sheep blood, Mac Conkey,
Mueller-Hinton agar.
K. granulomatis grow in the yolk sac of developing embryo or in cell cultures (fresh
mononuclear cells or Hep-2 cell line.
Widely distributed in nature. Isolated from soil and plants, where they seem to be
responsible for nitrogen fixation, also isolated from water, and some from clinical
specimens (human and animal).
K (capsular) and O (somatic) antigens are presented. Cross-reaction of K and O
antigens of Klebsiella with antigens of
E. coli, Streptococcus pneumoniae and
Salmonella paratyphi may occur. No H (flagellar) antigens presented.
Many strains produce bacteriocins.
- Klebsiella pneumoniae subsp. pneumoniae may cause infections of the urinary and
respiratory tract (pneumonia) in humans and animals (capsule type 1, 2 and 3), also
metritis in mares.
K. pneumoniae capsule type 1 and 2 are highly virulent for mice.
May cause meningitis, diarrhea, bacteremia, wounds and burns infections.
Produces enterotoxin similar to ST and LT and plasmid mediated.
Also isolated from plants – rice.
K. pneumoniae has been isolated from leg arthritis followed by leg necrosis and septicaemia in canaries (admin note).
- Klebsiella pneumoniae subsp. ozaenae occurs in ozena (a chronic disease of the nose characterized by a foul-smelling nasal
discharge and atrophy of nasal structures) and other chronic diseases of the respiratory tract.
- Klebsiella pneumoniae subsp. rhinoscleromatis causes a slowly progressing granulomatous disease of the nasal mucous
membrane (rhinoscleroma).
- Klebsiella granulomatis causes donovanosis (chronic genital ulceration).
-
Klebsiella grimontii was isolated from bacteraemia, wound infections, asymptomatic faecal carriage, diabetic foot syndrome and
antibiotic-associated haemorrhagic colitis.
-
Klebsiella huaxiensis was isolated from human urine.
-
Klebsiella indica was isolated from the exterior surface washing of a tomato.
-
Klebsiella oxytoca can be isolated from various clinical samples (including human feces), and from botanical and aquatic
environments.
-
Klebsiella pasteurii was isolated from feces of cows, turtles and humans.
-
Klebsiella quasipneumoniae, both subspecies were isolated from human blood cultures.
-
Klebsiella spallanzanii was isolated from human urine and cow feces.
- Klebsiella singaporensis was isolated from soil.
- Klebsiella africana was isolated from a fecal sample of a human asymptomatic carrier in Sokone, Senegal.
- Klebsiella variicola was isolated from plants and clinical samples.
  1. J. G. Holt et al., 1994. Facultatively Anaerobic Gram-Negative Rods. Subgroup 1. Family Enterobacteriaceae. In: Begey’s Manual of
    Determinative Bacteriology, 9th-edition, Williams & Wilkins, pp 175-189.
  2. Don J. Brenner and J.J. Farmer III, 2001. Family I. Enterobacteriaceae. In: Bergey’s Manual of Systematic Bacteriology, Second
    edition, Vol two, part B, George M. Garrity (Editor-in-Chief), pp 587-897.
  3. Carter J.S., Bowden F.J., Bastian I., Myers G.M., Sriprakash K.S. & Kemp D.J.: Phylogenetic evidence for reclassification of
    Calymmatobacterium granulomatis as Klebsiella granulomatis comb. nov. Int. J. Syst. Bacteriol., 1999, 49, 1695-1700.
  4. Sakazaki R., Tamura K., Kosako Y. and Yoshizaki E.: Klebsiella ornithinolytica sp. nov., formerly known as ornithine-positive
    Klebsiella oxytoca. Curr. Microbiol., 1989, 18, 201-206.
  5. Gavini F. et al.: Priority of Klebsiella planticola Bagley, Seidler, and Brenner 1982 over Klebsiella trevisanii Ferragut, Izard, Gavini,
    Kersters, De Ley, and Leclerc 1983. Int. J. Syst. Bacteriol., 1986, 36, 486-488.
  6. Li X., Zhang D., Chen F., Ma J., Dong Y. & Zhang L.: Klebsiella singaporensis sp. nov., a novel isomaltulose-producing bacterium.
    Int. J. Syst. Evol. Microbiol., 2004, 54, 2131-2136.
  7. Izard D., Ferragut C., Gavini F., Kersters K., De Ley J. & Leclerc H.: Klebsiella terrigena, a new species from soil and water. Int. J.
    Syst. Bacteriol., 1981, 31, 116-127.
  8. Rosenblueth M. et al.: Klebsiella variicola, a novel species with clinical and plant-associated isolates. Syst. Appl. Microbiol., 2004,
    27, 27-35
  9. R. Podschun et al.: Isolation of Klebsiella planticola from Newborns in a Neonatal Ward Journal of Clinical Microbiology, August
    1998, p. 2331-2332, Vol. 36, No. 8
  10. Adeolu M, Alnajar S, Naushad S, S Gupta R. Genome-based phylogeny and taxonomy of the 'Enterobacteriales': proposal for
    Enterobacterales ord. nov. divided into the families Enterobacteriaceae, Erwiniaceae fam. nov., Pectobacteriaceae fam. nov.,
    Yersiniaceae fam. nov., Hafniaceae fam. nov., Morganellaceae fam. nov., and Budviciaceae fam. nov. Int J Syst Evol Microbiol
    2016; 66:5575-5599.
  11. Rodrigues C, Passet V, Rakotondrasoa A, Diallo TA, Criscuolo A, Brisse S. Description of Klebsiella africanensis sp. nov.,
    Klebsiella variicola subsp. tropicalensis subsp. nov. and Klebsiella variicola subsp. variicola subsp. nov. Res Microbiol 2019; 170:
    165-170.
  12. Rodrigues C, Passet V, Rakotondrasoa A, Diallo TA, Criscuolo A, Brisse S. Erratum to "Description of Klebsiella africanensis sp.
    nov., Klebsiella variicola subsp. tropicalensis subsp. nov. and Klebsiella variicola subsp. variicola subsp. nov." [Res Microbiol 170
    (3) (2019) 165-170]. Res Microbiol. 2019 Sep-Oct;170(6-7):300. doi: 10.1016/j.resmic.2019.09.001. Epub 2019 Oct 5. Erratum for:
    Res Microbiol. 2019 Apr - May;170(3):165-170. PMID: 31594671.
  13. Passet V, Brisse S. Description of Klebsiella grimontii sp. nov. Int J Syst Evol Microbiol 2018; 68:377-381.
  14. Brisse S, Passet V, Grimont PA. Description of Klebsiella quasipneumoniae sp. nov., isolated from human infections, with two
    subspecies, Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and Klebsiella quasipneumoniae subsp.
    similipneumoniae subsp. nov., and demonstration that Klebsiella singaporensis is a junior heterotypic synonym of Klebsiella
    variicola. Int J Syst Evol Microbiol 2014; 64:3146-3152.
  15. Hu Y, Wei L, Feng Y, Xie Y, Zong Z. Klebsiella huaxiensis sp. nov., recovered from human urine. Int J Syst Evol Microbiol 2019; 69:
    333-336.
  16. Gujarati S, Chaudhari D, Hagir A, Khairnar M, Shouche Y, Rahi P. Klebsiella indica sp. nov., isolated from the surface of a tomato.
    Int J Syst Evol Microbiol 2020; 70:3278-3286.
  17. Merla C, Rodrigues C, Passet V, Corbella M, Thorpe HA, Kallonen TVS, Zong Z, Marone P, Bandi C, Sassera D, et al. Description
    of Klebsiella spallanzanii sp. nov. and of Klebsiella pasteurii sp. nov. Front Microbiol 2019; 10:2360.
Positive results for catalase, nitrate reduction (except K. singaporensis), esculin
hydrolysis (most strains), acid production from: L-arabinose, D-adonitol, cellobiose,
glucose, mannitol, melibiose, maltose, D-mannose, raffinose, salicin, trehalose and
D-xylose.

Negative results for oxidase, arginine dihydrolase, H
2S production, phenylalanine
deaminase, gelatin hydrolysis, DN-ase and lipase.
(c) Costin Stoica
Klebsiella pneumoniae on Mac Conkey agar
Antibiogram
Encyclopedia
Culture media
Biochemical tests
Stainings
Images
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Identification
Software
R E G N U M
PROKARYOTAE
 
ONPG
Lysine
decarboxylase
Ornithine
decarboxylase
Indole
production
Citrate
utilization
Voges-Proskauer
Urea
hydrolysis
Klebsiella oxytoca
+
+
-
+
+
+
+
Klebsiella pneumoniae
subsp. ozaenae
[+]
d
-
-
d
-
-
Klebsiella pneumoniae
subsp. pneumoniae
+
+
-
-
+
+
+
Klebsiella pneumoniae
subsp. rhinoscleromatis
-
-
-
-
-
-
-
Klebsiella africana
+
+
-
+
+
+
+
Klebsiella grimontii
+
+
+
+
+
+
-
Klebsiella huaxiensis
+
+
-
+
+
-
-
Klebsiella indica
+
-
-
+
+
-
-
Klebsiella michiganensis
+
+
-
+
+
+
-
K. quasipneumoniae subsp.
quasipneumoniae
+
+
-
-
+
+
+
K. quasipneumoniae subsp.
similipneumoniae
+
+
-
-
+
+
+
Klebsiella pasteurii
+
-
-
+
+
+
-
Klebsiella spallanzanii
+
+
-
+
+
-
+
Raoultella  ornithinolytica
+
+
+
+
+
[+]
+
Raoultella  planticola
+
+
-
[-]
+
+
+
Raoultella terrigena
+
+
[-]
-
d
+
+
Differential characters of the species from genera Klebsiella and Raoultella:
Legend: +  positive 90-100%, - negative 90-100%, [+] positive 75-89%, [-] negative 75-89%, d positive 25-74% of strains
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