YSM Issue 86.1

ENTOMOLOGY
would be a misnomer. Even within a single
bacterium species, the bacteria of the gut
microbiota can be divided into distinct
strains that vary widely in their metabolic
behavior. Different strains colonize the gut
in distinct patterns, with each strain likely
filling a unique niche. This large diversity
may confer an advantage to the host in
responding to a wide variety of environmental
conditions, fighting off pathogens
and metabolizing a range of toxins.
A Possible Link to Bee Deaths
One of Moran’s recent discoveries suggests
a possible link between the health
of the bee microbiota and CCD. Since
the 1950s, honey bees in the United States
have been treated with an antibiotic called
tetracycline to combat American foulbrood
(AFB), a disease characterized by infection
Beekeepers began reported losses of 30-90% of their honey bee colonies in the fall
of 2006. Courtesy of Waldan Kwong.
microbiota likewise developed resistance to
tetracycline in the form of eight different
resistance genes. As the introduction of the
new drug tylosin to target AFB coincided
with the outbreak of CCD in 2006, Moran
suggests the possibility that the drug was
disruptive to the gut community. Other
countries that restrict the use of antibiotics
in beekeeping did not experience a disappearance
of bees as large and as abrupt as
that in the United States in 2006.
Although this link between antibiotic use
and CCD has not been proven, it neverthe-
less suggests the importance of considering
the vital role that the gut microbiota of
honey bees play in keeping bees and their
colonies healthy. The gut community, welldefined
in the honey bee, may be inseparable
from its host. These symbionts are crucial
for the honey bees in their absorption of
food, removal of toxins, and potentially in
their defense against pathogens. What other
benefits these bacteria confer is unknown,
but Moran’s research is helping us take steps
toward understanding what may lie at the
very core of honey bee health.
About the Author
Katie Leiby is a junior in Silliman College majoring in biomedical engineering. She
works in Dr. Laura Niklason’s lab characterizing the extracellular matrix of decellularized
lungs.
Acknowledgements
The author would like to thank Professor Moran for her time and her enthusiasm in
sharing her research.
The antibiotics used to combat American
foulbrood may be linked to Colony
Collapse Disorder. Courtesy of beeinformed.org.
by spores. Once a colony gets AFB, the
entire colony needs to be destroyed, resulting
in large costs for the beekeeper. By the
1990s, the drug target had become resistant,
and efforts were initiated to find a new antibiotic.
Moran found that the honey bee gut
Further Reading
• Nancy Moran et al., “Distinctive Gut Microbiota of Honey Bees Assessed Using
Deep Sampling from Individual Worker Bees,” PLOS ONE, April 27, 2012; 7(4):
e36393. doi: 10.1371/journal.pone.0036393.
• Engel, Philipp, Vincent G. Martinson, and Nancy A. Moran, “Functional diversity
within the simple gut microbiota of the honey bee,” PNAS, June 18, 2012; 109(43).
doi: 10.1073/pnas.1202970109.
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January 2013 | Yale Scientific Magazine 19