Legend: +  positive 90-100%, - negative 90-100%, [+] positive 75-89%, [-] negative 75-89%, d positive 25-74% of strains
Genus Morganella
Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Proteobacteria, Class Gammaproteobacteria, Order Enterobacteriales, Family Enterobacteriaceae, Genus Morganella,
Morganella morganii subsp. morganii  (Winslow et al. 1919) Jensen et al. 1992  - type species of the genus, old synonym Proteus
morganii,
Morganella morganii subsp. sibonii
Jensen et al. 1992,
Morganella psychrotolerans  Emborg et al. 2006.
Gram negative, 1.0 x 1.7 µm, straight rods.  
Large, gray, moist colonies (beta haemolytic). No special growth requirements.
Facultatively anaerobic, growth temperature 30-37 ºC and below (
Morganella
psychrotolerans
can produce toxic concentrations of histamine in seafood at 2-5 ºC).
Grow on: Nutrient agar or nutrient brot; Trypticase Soy Agar ± 5% sheep blood;
MacConkey agar.
Widely distributed in nature (soil, water, foods). Isolated from human & animal stools.
Unknown clinical significance – opportunistic pathogen. Isolated from intestine, urinary infections, absceses, pericarditis,
endophthalmitis (most infections occurred after surgical interventions).
Morganella psychrotolerans have been involved in histamine fish poisoning caused by eating seafood in which bacteria have
produced high concentrations of histamine.
  1. J. G.Holt et al., 1994. Begey’s manual of Determinative Bacteriology, 9th-edition, Williams & Wilkins.1994;
  2. Jensen K.T., Frederiksen W., Hickman-Brenner F.W., Steigerwalt A.G., Riddle C.F. & Brenner D.J.: Recognition of Morganella
    subspecies, with proposal of Morganella morganii subsp. morganii subsp. nov. and Morganella morganii subsp. sibonii subsp.
    nov. Int. J. Syst. Bacteriol., 1992, 42, 613-620.
  3. Fulton MacD.: The identity of Bacterium columbensis Castellani. Journal of Bacteriology, 1943, 46, 79-81.
  4. Emborg Jette, Dalgard Paw & Ahrens Peter: Morganella psychrotolerans sp. nov., a histamine-producing bacterium isolated
    from various seafoods. Int. J. Syst. Evol. Microbiol., 2006, 56, 2473-2479.
  5. 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.
Positive results for catalase, urease, phenylalanine deaminase, nitrate reduction, tartrate & acid production from: glucose (with gas
production).

Negative results for oxidase, ONPG, arginine dihydrolase, citrate utilization, H
2S production, Voges-Proskauer reaction, gelatinase,
malonate utilization, esculin hydrolysis, acetate utilization, DN-ase, lipase
acid production from lactose, mannitol, inositol, sorbitol, rhamnsoes, sucrose, melibiose, arabinose, cellobiose, dulcitol, glycerol,
alpha-methyl-D-glucoside, raffinose, salicin, xylose, mucate, erythritol & adonitol
(c) Costin Stoica
Antibiogram
Encyclopedia
Culture media
Biochemical tests
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R E G N U M
PROKARYOTAE
 
Lysine
decarboxylase
Ornithine
decarboxylase
Indole
production
Motility
Maltose
fermentation
Trehalose
fermentation
M. morganii subsp. morganii
-
+
+
+
-
-
M. morganii subsp. sibonii
d
d
d
[+]
-
+
M. morganii biotype 1
+
[+]
+
-
+
-
Morganella psychrotolerans can be differentiated from M. morganii by the ability to grow at 2 °C but not 37 °C, inability to grow in 8.5%
NaCl, variable fermentation of D-trehalose (negative for
M. morganii) and no fermentation of D-galactose (positive for M. morganii).
Differential characters of the
M. morganii subspecies & biotypes:
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