Phylum Proteobacteria, Class Gammaproteobacteria, Order Pseudomonadales, Family Moraxellaceae, Genus Moraxella, Moraxella
nonliquefaciens (Scarlett 1916) Lwoff 1939.
Old synonym: Bacillus duplex non liquefaciens Scarlett 1916.
Gram-negative rods, showing variation in shape, size, and arrangement. Nonmotile.
Colonies are translucent to semiopaque. Some strains are very mucoid. Cell walls of
nonmucoid strains often contain polysaccharide that is chemically and
immunologically identical to capsular polysaccharide of serogroup B meningococci.
Nonfimbriated variants occur spontaneously in cultures and form noncorroding,
nonspreading colonies which are convex and usually larger than their corroding
counterparts (often 3.0 mm after 48 h), and have a butyrous consistency. Fimbriated
cells of collection strains may also form large colonies, but these may be less
corroding than the colonies of fresh isolates. Nonhemolytic. Optimal growth occurs at
35-37 ºC. Variable growth at 42 ºC. No growth on Hugh and Leifson’ s OF medium,
MacConkey agar or in minimal medium containing ammonium and acetate.
Isolated from the respiratory tract, including nasal cavity (the natural habitat), bronchial aspirates in chronic bronchitis and upper
Usually nonpathogenic. May be involved in respiratory disease. It has been found in individuals with endophthalmitis and occasionally
in blood in systemic disease.
- Elliot Juni and Kjell Bovre. Order IX Pseudomonadales Orla-Jensen 1921, Family II Moraxellaceae Rossau, Van Landschoot,
Gillis and De Ley 1991 In: Bergey’s Manual of Systematic Bacteriology, Second edition, Vol two, part B, George M. Garrity (Editor-
in-Chief), pp. 411-442.
- D L Sharma. Fatal septicaemia due to Moraxella non liquefaciens (sic). Arch Dis Child. 1974 December; 49(12): 966–967.
- Kjell Bovre and S. D. Henriksen. A new Moraxella species, Moraxella osloensis, and a revised description of Moraxella
nonliquefaciens. Int J Syst Bacteriol April 1967 17:127-135.
Positive results for catalase, esterase, nitrate reduction & oxidase.
Negative results for alkaline & acid phosphatase, DN-ase, gelatin liquefaction, H2S production, indole production, phenylalanine
deaminase, Tween 80 hydrolysis. No acid production from glucose and other sugars. Urea hydrolysis is lost in subcultures.
(c) Costin Stoica