Power Point for research paper presentation by Kevin Hugins. Through microbial endocrinology other treatments may be developed. As this paper has discussed, application of these techniques may one day provide a treatment for pathogens other than the traditional antibiotics. It may lead to techniques for dealing with auto-immune diseases. Considering the sheer numbers of microorganisms in our microbiota and all we have yet to learn on the molecular level, this field of research may answer questions we do not even know we have yet.

1. Microbial Endocrinology
Kevin Hugins
Biology 414-001
Kebret Kebede, M.D.
Nevada State College
Fall 2014

2. Microbial Endocrinology
Mark Lyte, Ph.D.
American Society for Microbiology General Meeting:
● Suggested bacteria recognize and respond to human
stress hormones and alter behavior accordingly.
● 1992 - 2 people attended
● 2007 - Filled auditorium
Current research has found some microorganisms can produce
neuroendocrine hormones:
● GABA
● Serotonin
● Acetylcholine
● Catecholamines
● Melatonin (Wang 2013)
http://www.ttuhsc.edu/facultysenate/images/Lyte_Mark.jp
g

3. Human Microbiota
Ratio of bacterial cells to human cells 10:1
Exist in symbiotic relationship with human host
Anxiety and stress can affect microbiota in human gut.
Hormone responsive gut bacteria:
Escherichia coli
Salmonella
Listeria
Campylobacter
Yersinia (Sharaff 2011)
http://www.cdc.gov/pulsenet/images/campy
-300px.jpg
http://www.cdc.gov/pulsenet/images/ecoli2-
300px.jpg
http://www.cdc.gov/pulsenet/images/salmon
ella-300px.jpg

4. Neuroendocrine hormones can alter virulance of bacteria and stimulate
growth. (Lyte 2013)
Microorganisms responsible for respiratory infection experience
exponential cell growth when exposed to catchecholamines:
Pseudomonas aeruginosa
Bordetella pertussis
Bordetella bronchiseptica
Klebsiella pneumonia
http://ehp.niehs.nih.gov/wp-
content/uploads/120/5/ehp.120-
a190.g001.png
http://media.historyofvaccines.org/i
mages/000744_540.jpg
http://klebsiella-
pneumoniae.org/klebsiella_pneumoniae_urinar
y_tract_infection_2.jpg

5. Insulin-like Receptors
Some fungi, protozoa and bacteria have insulin-like receptors on cell surface.
Burkholderia cepacia
Burkholderia pseudomallei
Streptococcus (some species)
Some microbial species show high affinity for insulin.
Aeromonas salmonicida
Burkholderia multivorans
Burkholderia cenocepacia
Infections with these organisms may contribute to an autoimmune response
leading to insulin dependent diabetes. (Nisr 2012)
https://www.sanger.ac.uk/about/pres
s/2004/gfx/040914_burk_300.jpg

6. Sex Steroids
Increasing exposure to testosterone and dihydrotestosterone (DHT) caused
considerable acceleration in cell division in E. coli.
Increase in corticosteroid dexamethasone caused increased speed of cell
division in S. aureus and E. faecalis.
Testosterone and DHT exposure Pseudomonas aeruginosa demonstrated an
eight fold increase in resistance to antimicrobial agent Cefepime.
Exposure of Entrococcus faecalis to testosterone resulted in Meropenem
insensitivity and exposure to DHT caused resistance to Norfloxacin.
(Plotkin 2003)

7. Androgens
Due to hormonal differences, the gut microbiota of males and females differs.
(Yurkovetskiy 2013)
Difference influenced by androgens.
● Microbiota between sexes is relatively the same from birth to puberty.
● At puberty male microbiome begins to change, becoming less diverse.
● Castration causes male gut microbiota to reverse and become more like
juveniles and females.
http://www.chemistry-blog.com/wp-
content/uploads/2008/01/beaker_by_chareen.jpg

8. Autoimmunity
Autoimmune diseases such as multiple sclerosis and rheumatoid arthritis
afflict women more commonly than men at younger ages.
This gap begins to close as men age and testosterone production declines.
Non-obese type-1 diabetes in mice.
More prevelant in females than males
Casteration increased incidence in males
Administration of androgen to females reduced incidence
(Markle 2013)
Enough
with the
castration!!
http://www.chemistry-blog.com/wp-
content/uploads/2008/01/beaker_by_chareen
.jpg

9. Infections In Intensive Care Patients
Coagulase-negative staphylococci (CoNS)
● Typically present on our skin showing low pathogenicity.
● CoNS infections common in intensive care patients.
● CoNS biofilms form on intravenous catheters of patients
● In medical settings, catecholamines are administered to patients
through intravenous catheters
● Staphylococci that appear dead due to antibiotics can recover
when exposed to catecholamines
● Catecholamines have exponential effect on the development of
staphylococcal biofilms (Sharaff 2011)

10. Today Microbial Endocrinology is defined as:
● The study of the ability of microorganisms to both produce and recognize
neuro chemicals that originate either within the microorganisms
themselves or within the host they inhabit.
Researchers must take an interdisciplinary approach to include the fields of
microbiology, neurobiology and endocrinology.
Research and understanding in this field has come a long way since Mark
Lyte gave his talk to an empty auditorium in 1992.

11. References
Lyte, M., & Freestone, P. (2009). Microbial Endocrinology Comes of Age. Microbe Magazine, 4(4), 169-175. Retrieved from
http://www.microbemagazine.org/index.php?option=com_content&view=article&id=281:microbial-endocrinology-comes-of-age&Itemid=263
Lyte, M. (2013). Microbial Endocrinology in the Microbiome-Gut-Brain Axis: How Bacterial Production and Utilization of Neurochemicals Influence
Behavior (V. Miller, Ed.). PLoS Pathogens, 9(11), E1003726. doi: 10.1371/journal.ppat.1003726
Markle, J. G., Frank, D. N., Mortin-Toth, S., Robertson, C. E., Feazel, L. M., Rolle-Kampczyk, U., ... Danska, J. S. (2013). Sex Differences in the Gut
Microbiome Drive Hormone-Dependent Regulation of Autoimmunity. Science, 339(6123), 1084-1088. doi: 10.1126/science.1233521
Nisr, R. B., Moody, A. J., & Gilpin, M. L. (2012). Screening microorganisms for insulin binding reveals binding by Burkholderia multivorans and
Burkholderia cenocepacia and novel attachment of insulin to Aeromonas salmonicida via the A-layer. FEMS Microbiology Letters, 328(2), 93-99. doi:
10.1111/j.1574-6968.2011.02484.x
Plotkin, B. J., Roose, R. J., Erikson, Q., & Viselli, S. M. (2003). Effect of Androgens and Glucocorticoids on Microbial Growth and Antimicrobial
Susceptibility. 47(6), 514-520. doi: 10.1007/s00284-003-4080-y
Sharaff, F., & Freestone, P. (2011). Microbial Endocrinology. 6(5), 685-694. doi: 10.2478/s11535-011-0067-z
Wang, Y., & Kasper, L. H. (2013). The role of microbiome in central nervous system disorders. Brain, Behavior, and Immunity, 38, 1-12. doi:
10.1016/j.bbi.2013.12.015
Yurkovetskiy, L., Burrows, M., Khan, A., Graham, L., Volchkov, P., Becker, L., ... Chervonsky, A. (n.d.). Gender Bias in Autoimmunity Is Influenced by
Microbiota. Immunity, 39(2), 400-412. doi: 10.1016/j.immuni.2013.08.013