Category: Talya Klinger

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Bacteria, Botulism, and Beauty

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By Talya Klinger, MSS Intern

The molecular structure of botulinum toxin
What do foodborne illnesses, neck dystonia treatments, and celebrities’ beauty regimens have in common? Clostridium botulinum, baratii, and other species of Clostridium bacteria produce all of the above and more. These seemingly innocuous, rod-shaped bacteria, commonly found in soil and in the intestinal tracts of fish and mammals, produce one of the most deadly biological substances: botulinum toxin, a neurotoxin that intercepts neurotransmitters and paralyzes muscles in the disease known as botulism. Nonetheless, botulinum toxin isn’t all bad: this chemical not only protects the bacteria from intense heat and high acidity, but it makes for an effective treatment for medical conditions as wide-ranging as muscle spasms, chronic migraines, and, yes, wrinkles. 


C. botulinum
Clostridium botulinum and similar bacteria can make their way into the human body in a number of ways. Wounds infected with Clostridium botulinum or spores ingested by infants can lead to the rare but serious disease of botulism, as can accidental overdoses of medicinal or cosmetic botulinum toxin. Botulism is often foodborne, usually contracted by infants from honey or by adults from improperly home-canned foods and unrefrigerated herb-infused oils. Regardless of where any case of botulism comes from, it causes muscle paralysis, which can manifest as blurred vision, dry mouth, and muscle weakness in adults or lethargy and constipation in infants. These are only early warning signs for an illness that, if left untreated, can paralyze a patient’s respiratory muscles to the point of asphyxiation. Although 95-97% of botulism patients receive treatment and survive, they often require months of intensive care and suffer years of muscle weakness, fatigue, and shortness of breath.

So how does the neurotoxin that makes botulism so deadly work? Clostridium bacteria produce several protein compounds with similar structures and molecular weights, consisting of two chains of amino acids—one small and one large. These two amino acid chains are linked together by a covalent bond between two sulfur atoms, one in each chain. The botulinum toxin proteins bind to nerve endings where they join muscles, blocking the neurotransmitter acetylcholine, which ordinarily causes muscle contractions. This blockage is permanent, paralyzing the muscle until a new nerve ending forms a synaptic connection with it. Because the process of forming new neuromuscular junctions takes at least 2 or 3 months, the affected muscle will often atrophy in the meantime, causing the long-term side effects that plague botulism survivors.

Ironically, the very mechanisms that make botulinum toxin so dangerous give it a wide range of beneficial medical applications. When botulinum toxin is administered in small, controlled doses, its muscle-contraction preventing effects make it a viable treatment for neck dystonia, sustained involuntary eyelid closure, chronic migraines, neurogenic bladder dysfunction, and other conditions caused by involuntary muscle movements. In popular culture and tabloid media, Botox’s serious medical applications are often overshadowed by its cosmetic notoriety: smoothing out wrinkles. Cosmetic Botox inhibits the neuromuscular activity that leads to wrinkles, relaxing the surrounding skin. Seeming to reverse one of the telltale signs of aging may have given botulinum toxin its Hollywood appeal, but its wide ranging pharmaceutical uses are what continue to fascinate research scientists.

In a nutshell, the molecule botulinum toxin is a toxic protein made by clostridium botulinum bacteria. In measured amounts, the toxic protein is marketed as Botox for pharmaceutical uses. When uncontrolled doses of the bacteria are ingested, however, Clostridium botulinum can result in deadly cases of muscle paralysis called botulism. 

 If you are intrigued by the terrible beauty of such a versatile molecule as botulinum toxin, come to Marin Science Seminar on September 30th, at Terra Linda High School, 320 Nova Albion Way, in Room 207 from 7:30 to 8:30 pm, when bioanalysis and pharmacology expert Dr. Erik Foehr will discuss his research on botulinum toxin.


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An Interview with Dr. Jenna Judge, Marine Biologist

by Talya Klinger, MSS Intern

Driftwood is a common sight on beaches, but what happens to driftwood when it sinks to the seafloor? Dr. Jenna Judge, a recent doctoral graduate of UC Berkeley’s Department of Integrative Biology, researches evolution and ecology in deep-sea habitats, such as driftwood, as well as hydrothermal vents and sunken whale bones. Her research shows that these unusual substrates host diverse, lively communities shaped by the wood they inhabit. Attend her research presentation at Terra Linda High School, Room 207, from 7:30-8:30 pm on September 9th.


In Dr. Judge’s words:


1.   Why did you decide to become a marine biologist in the first place?

Well, I grew up in the mountains, but I was always interested in nature and science. I also loved the beach when my family would go on camping trips to the coast. However, I really decided to pursue marine biology in high school after learning about extreme deep-sea environments and the strange animals that live there from my AP Biology teacher. From there, I looked for colleges that offered a marine biology major for undergraduates and went to UC Santa Barbara. My interests in the ocean and the deep sea in particular were reinforced with each class I took and especially the semester abroad I spent in Australia doing a marine biology program. At the time, the obvious next step for me to take was to apply to graduate school to pursue a career as a marine biologist. While this route has served me well, I usually advise college students to take some time after graduation to explore options before jumping into graduate school. It is a big decision, and it’s important to have a strong sense of yourself and what you want to get out of an advanced program before choosing a program and an adviser.

2.  How did you decide to research driftwood?

I ended up studying sunken wood as a habitat for deep-sea animals after learning that the communities on wood are similar to other deep-sea ecosystems I was initially interested in, but had been much less studied. These ecosystems were hydrothermal vents (basically deep-sea volcanoes), cold seeps, and whale falls, which I’ll explain more about in my talk. Due to a series of conversations with scientists at the Monterey Bay Aquarium Research Institute, I was given the opportunity to test whether the kind of wood matters in shaping animal communities by sinking a bunch of wood at about 2 miles deep and waiting 2 years to see what happened. You’ll see what happened during my talk.

3.   How does your work on communities that form around driftwood relate to other ecosystems?

The experiment I did on sunken wood showed that, like forests and other terrestrial (land) ecosystems, the immediate habitat can act as a filter that shapes the community that colonizes that habitat. This means that the ocean isn’t just a big bathtub with a soup of organisms floating or swimming through it, but that even on small scales, the complexity of a habitat can significantly affect who decides to settle down there. I see all ecosystems as a connected web across the Earth, and I am especially interested in links between the land and the ocean, like wood, but also how the increase in artificial materials like plastic is affecting marine ecosystems.

4.  What advice do you have for high school students who aspire to be biologists?

Follow your curiosity! Ask questions and read about what interests you to keep learning and following your interests. Reach out to people who are doing things you find interesting. Scientists are always happy to hear from people who appreciate what they are doing, and it will help you learn more about what it might be like to pursue certain career paths. And once you have some ideas, research colleges that will support that passion and allow you to fully explore and develop your passion. You might find that the best program for you isn’t at the “top” university in the state or the country. For me, I was only looking at CA schools, and I was really excited about marine biology. So, I focused on applying to schools that had specific aquatic or marine biology majors like UCSB and UCSC, but I did not bother applying to UC Berkeley or UCLA even though they rank higher overall. I encourage you to find a good fit for your interests (and of course a good personal fit!) when choosing a college, and if you don’t have a clear idea about what you want to pursue (most people don’t, I was unusually focused), take your time. If you are looking to pursue marine biology in particular, here is a good site that lists all the programs across states: http://marinebio.org/marinebio/careers/us-schools/.

5.  One final question: do you have a favorite driftwood-dwelling creature?

My favorite wood-dwelling creatures would have to be limpets, since they are what led me to studying sunken wood in the first place. Limpets are snails that have no coil in their shell and a particular group of them are specialized to live in a wide range of deep-sea habitats, including hydrothermal vents, cold seeps, whale falls, and sunken wood. They also  live on empty shark egg cases, crab carapaces, worm tubes, squid beaks, algal holdfasts, and likely other organic substrates that sink to the bottom. 

Join us Wednesday, September 9th, 2015, 7:30 – 8:30 pm at Terra Linda HS, 320 Nova Albion, San Rafael – Room 207 – to hear Dr. Judge talk about her work.  Link to Dr. Judge’s Marin Science Seminar profile. 

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