Pathogenesis, Epidemiology and Variants of Melissococcus plutonius (Ex White), the Causal Agent of European Foulbrood

Abstract

The bacterium Melissococcus plutonius is the etiologic agent of the European foulbrood (EFB), one of the most harmful bacterial diseases that causes the larvae of bees to have an intestinal infection. Although EFB has been known for more than a century and is practically present in all countries where beekeeping is practiced, the disease has been little studied compared to American foulbrood. Recently, great advances have been made to understand the disease and the interaction between the pathogen and its host. This review summarizes the research and advances to understand the disease. First, the morphological characteristics of M. plutonius, the infection process and bacterial development in the gut of the larva are described. Also, the epidemiological distribution of EFB and factors that favor the development of the disease as well as the classification of M. plutonius according its genomic and phenotype characteristics are reported. Finally, the new molecular tools for the study of M. plutonius, possible virulence factors in its genome, the issue of current EFB control measures and possible alternatives to the use of antibiotics are addressed.

IPM Strategy to Control EFB in Apis mellifera: Oxytetracycline Treatment Combined with Partial Shook Swarm and Queen Caging

“…The shook swarm method, both TSS and PSS, is reported as an alternative to OTC treatment in the case of EFB. The combination of TSS and OTC treatment was found to reduce the recurrence of EFB at the colony level [ 9 ]. We monitored the experimental apiary for 7 months after the PSS, assessing the sucrose solution consumption, colony strength, side effects, honey yield, and relapses, and collected samples for the laboratory investigation (residues of OTC in the honey and real-time PCR analyses for the M. plutonius gene sequence).…”

“…The presence of M. plutonius has been confirmed in five continents. Among the member states of the World Organization for Animal Health (WOAH), Nicaragua and Mozambique are the only nations to have never reported the presence of EFB by 2019 [ 9 ].…”

Biotic and abiotic stresses on honeybee health

“…Nosema ceranae) pathogens threaten honeybee health. Paenibacillus larvae and M. plutonius, the causative agents of American foulbrood and European foulbrood, mainly infect the larvae of A. mellifera and A. cerana, respectively, consequently leading to the collapse of a colony if left untreated (Alonso-Salces et al 2017;de León-Door et al 2020;Devi et al 2021). Although the absence of antibodies in insects leads to a deficiency in transgenerational immunity, the survival rate of the offspring of orally vaccinated queens can be largely increased after P. larvae challenge (Dickel et al 2022).…”

Evaluation of Functional Properties of Some Lactic Acid Bacteria Strains for Probiotic Applications in Apiculture

“…Viruses like the deformed wing virus, often transmitted by parasitic mites such as Varroa destructor [ 8 ], severely weaken bee colonies. Bacterial infections, notably American Fulbrood caused by Paenibacillus larvae [ 9 ] and European Foulbrood caused by Melissococcus plutonius , and other associated bacterial flora consisting of Paenibacillus alvei , Enterococcus faecalis , and Bacterium eurydice , lead to substantial brood mortality [ 10 , 11 ]. Fungal pathogens, especially Nosema ceranae , cause nosemosis, impacting bees’ digestive tracts [ 12 , 13 ], while chalkbrood caused by Ascosphaera apis affects larvae [ 14 ].…”