Moraxella lacunata

Moraxella lacunata is a rod-shaped,^[1] Gram-negative, nonmotile bacterium, generally present as diploid pairs.^[2] It causes one of the commonest forms of catarrhal conjunctivitis.^[3]

Moraxella lacunata
Microscope view of Moraxella lacunata bacteria
Scientific classification
Domain:	Bacteria
Kingdom:	Pseudomonadati
Phylum:	Pseudomonadota
Class:	Gammaproteobacteria
Order:	Pseudomonadales
Family:	Moraxellaceae
Genus:	Moraxella
Species:	M. lacunata
Binomial name
Moraxella lacunata (Eyre 1900) Lwoff 1939 (Approved Lists 1980)

History

Moraxella lacunata was first described independently by Victor Morax (1896) and Theodor Axenfeld (1897), hence the alternate name "Morax-Axenfeld diplobacilli" and the name of eye infection in humans is sometimes called Morax-Axenfeld conjunctivitis.^[2]

Characters

It has the ability to change its morphology in laboratory. M. lacunata became shorter and tended to lose its Gram-negative staining characteristic when left out for 5 days. It also tended to retain these new characteristics on subsequent blood-agar transfers.^[4]

Clinical significance

Infection occurs mainly in adults, but can occur at any age. It is characterized by:

• Chronic, mild angular blepharoconjunctivitis frequently localized on the lid at the outer canthus
• Typical erythema of the edges of the lids
• Slight maceration of the skin, most marked at the angles, especially the outer canthus
• Superficial infiltration of the cornea is not uncommon.^[3]
• The discharge is grayish yellow, adherent to the lashes, and accumulates mainly at the angles.^[5]