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

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]

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]