title: How natural infection by Nosema ceranae causes honeybee colony collapse.
abstract: In recent years, honeybees (Apis mellifera) have been strangely disappearing from their hives, and strong colonies have suddenly become weak and died. The precise aetiology underlying the disappearance of the bees remains a mystery. However, during the same period, Nosema ceranae, a microsporidium of the Asian bee Apis cerana, seems to have colonized A. mellifera, and it's now frequently detected all over the world in both healthy and weak honeybee colonies. For first time, we show that natural N. ceranae infection can cause the sudden collapse of bee colonies, establishing a direct correlation between N. ceranae infection and the death of honeybee colonies under field conditions. Signs of colony weakness were not evident until the queen could no longer replace the loss of the infected bees. The long asymptomatic incubation period can explain the absence of evident symptoms prior to colony collapse. Furthermore, our results demonstrate that healthy colonies near to an infected one can also become infected, and that N. ceranae infection can be controlled with a specific antibiotic, fumagillin. Moreover, the administration of 120 mg of fumagillin has proven to eliminate the infection, but it cannot avoid reinfection after 6 months. We provide Koch's postulates between N. ceranae infection and a syndrome with a long incubation period involving continuous death of adult bees, non-stop brood rearing by the bees and colony loss in winter or early spring despite the presence of sufficient remaining pollen and honey.
authors.affiliation: Bee Pathology laboratory, Centro Apícola Regional, JCCM, 19180 Marchamalo, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Higes
authors.forename: Raquel
authors.initials: R
authors.lastname: Martín-Hernández
authors.forename: Cristina
authors.initials: C
authors.lastname: Botías
authors.forename: Encarna Garrido
authors.initials: EG
authors.lastname: Bailón
authors.forename: Amelia V
authors.initials: AV
authors.lastname: González-Porto
authors.forename: Laura
authors.initials: L
authors.lastname: Barrios
authors.forename: M Jesús
authors.initials: MJ
authors.lastname: Del Nozal
authors.forename: José L
authors.initials: JL
authors.lastname: Bernal
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Jiménez
authors.forename: Pilar García
authors.initials: PG
authors.lastname: Palencia
authors.forename: Aránzazu
authors.initials: A
authors.lastname: Meana
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D001516:Bees / Q000382:microbiology* / Q000648:ultrastructure; D003510:Cyclohexanes / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D041981:Gastrointestinal Tract / Q000473:pathology; D008853:Microscopy; D046529:Microscopy, Electron, Transmission; D016881:Microsporidiosis / Q000382:microbiology* / Q000473:pathology; D016818:Nosema / Q000302:isolation & purification*; D012717:Sesquiterpenes / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D003510:Cyclohexanes; D005231:Fatty Acids, Unsaturated; D012717:Sesquiterpenes; C026211:fumagillin