Melissococcus pluton

Definition

Obsolete name for Melissococcus plutonius, a Gram-positive, non-spore-forming bacterium in the family Enterococcaceae that causes European foulbrood, a larval disease of the western honey bee (Apis mellifera). The organism was originally described as Bacillus pluton by White in 1912, later reclassified as Streptococcus pluton, and finally placed in the genus Melissococcus by Bailey and Collins in 1983. The specific epithet was subsequently corrected to plutonius to adhere to Latin grammatical rules for bacterial nomenclature. Infection occurs when larvae ingest contaminated food, leading to gut sepsis, reduced appetite, and characteristic twisted or discolored brood; secondary invaders often complicate diagnosis.

Etymology

From Greek melissa (honey bee) + Greek kokkos (grain/berry), referring to the bacterium's association with bees and its coccoid morphology; pluton from the original description by White, alluding to Pluton/Pluto, classical god of the underworld, perhaps metaphorically to the disease's lethal effect on brood.

Example

A beekeeper observing spotty brood pattern and larvae that appear molten or twisted in their cells might submit samples for Melissococcus plutonius culture or PCR detection, though the obsolete literature may still reference the pathogen as Melissococcus pluton.

Synonyms

• Melissococcus plutonius
• Streptococcus pluton
• Bacillus pluton

Related Terms

• European foulbrood
• Apis mellifera
• Paenibacillus larvae
• brood disease
• honey bee pathology
• melissococcus

Usage Notes

The name Melissococcus pluton appears in older literature and some databases but is nomenclaturally invalid; the correct current name is Melissococcus plutonius. Specialists in bee pathology and veterinary microbiology use the corrected form exclusively. The bacterium is facultatively anaerobic and fastidious, requiring specialized media for isolation. Distinguish from Paenibacillus larvae, which causes the more serious American foulbrood; European foulbrood caused by M. plutonius is often less lethal and may resolve with improved colony nutrition or hygiene.