Battling a Honey Bee Pathogen

Our health is impacted directly by human specific pathogens and indirectly by pathogens affecting other organisms important to us. One such organism is the honey bee or Apis mellifera as biologists sometimes refer to them. In recent years honey bees have been afflicted by an array of problems which has produced disease and death in honey bee colonies as well as the dreaded colony collapse disorder. Honey bee health problems appear to be exacerbated by increased world trade which introduces new organisms into habitats they were previously not part of.

Genomic Analyses of the Microsporidian Nosema ceranae, an Emergent Pathogen of Honey Bees is a research paper published by PLOS Pathogens and authored by R. Scott Cornman, Yan Ping Chen, Michael C. Schatz, Craig Street, Yan Zhao, Brian Desany, Michael Egholm, Stephen Hutchison, Jeffery S. Pettis, W. Ian Lipkin and Jay D. Evans. The paper is focused on an organism known as Nosema ceranae or N. ceranae; the abbreviation generally used by scientists. N. ceranae is a unicellular parasitite of adult honey bees and belongs to the microsporidia phylum which are spore-forming parasites. The research group sequenced the genome of N. ceranae so as to better understand the organism. Increased understanding can lead to effective strategies that mitigate infectious damage to honey bee colonies.

The authors traced the possible proliferation pathway for N. ceranae:

N. ceranae was first described from colonies of the Asian honey bee, Apis cerana, that were sympatric with A. mellifera colonies in China. Fries et al. [5] suggested that a host switch from A. ceranae to A. mellifera occurred relatively recently. Currently, N. ceranae is the predominant microsporidian parasite of bees in North America [6] and Europe [3].

The paper depicts health effects of the pathogen:

Health impacts of Nosema infection on honey bees include a decreased ability to acquire nutrients from the environment and ultimately a shortened lifespan [8]. At the colony level, Nosema infection can lead to poor colony growth and poor winter survivorship.

The linkage between Colony Collapse Disorder (CCD) and N. ceranae are not precisely specifiable. The pathogen may be a contributory cause or one of several pathogenic challenges resulting in CCD. By sequencing the N. ceranae genome it is hoped that we are closer to being able to safeguard the welfare of honey bees. Honey bees provide billions of dollars of pollination services to farmers in the United States, making possible the food we purchase at reasonable prices. Of course honey bees provide honey and other bee products as well and are extremely valuable to us.

The authors suggest a possible approach to treating N. ceranae infections in honey bees by noting that genes encoding signal peptides may be found in proteins that interact with tissue of the host honey bees. Medications able to disrupt regulatory mechanisms in humans have proven to be effective in the treatment of various diseases. Perhaps parallel strategies will aid honey bees in resisting the N. ceranae parasite.