Morax-Axenfeld diplobacilli

Morax-Axenfeld diplobacillus or Moraxella lacunata is a rod-shaped,^[1] Gram negative, non motile bacteria, generally present as diploid pairs.^[2] They cause one of the commonest forms of catarrhal conjunctivitis.^[3]

History

M. lacunata was first described independently by Victor Morax (1896) and Theodor Axenfeld (1897), hence the name "Morax-Axenfeld diplobacilli" and the name of eye affection 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 their Gram-negative staining characteristic when left out for 5 days. They 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:

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

References