Isolation and characterization of Rothia mucilginosa from a human oral microbiome sample
Cristina Mondelli
This paper reports the results of isolation and characterization of Rothia mucilginosa from the mouth of an eleven year old boy. More information can be found here.
Positively-Delicious & No-Negativity Here White Chocolate Cheesecake
Cristina Mondelli
Cheesecake
For the longest time I had the hardest time remembering the difference between gram-positive and gram-negative staining. Fortunately, designing a dessert around these two types of bacteria made studying much more fun! Gram-staining is a critical part of characterizing an unknown bacterial species. Gram-negative bacteria turn pink/red under the microscope after staining while gram-positive bacteria turn purple. The crystal violet stain included in gram-staining gives the peptidoglycan layer its purple color in gram-positive bacteria. The thick peptidoglycan layer is modeled in the dessert by the thick white chocolate cheesecake layer. The gram-positive cheesecake is covered in a dark purple blackberry topping to represent the way the cells look under a microscope. The gram-negative cheesecake has several layers representing the various layers of the cell membrane. The bottom crust is the plasma membrane and the red strawberry layer is the periplasmic membrane. The cheesecake also represents the peptidoglycan layer in the gram-negative bacteria. Red strawberries were chosen because the color matches gram-negative bacteria.
Elusive microbe that consumes ethane found under the sea
Stephen W. Ragsdale 3/27/2019
https://www.nature.com/articles/d41586-019-00842-2
Summary: In anoxic regions of the ocean a microbe is able to oxidize ethane with the help of its neighbors. Several other species are able to break down methane, propane, and butane. In environments which contain oxygen, using these molecules is thermodynamically favorable. In the absence of oxygen, it is much less favorable, and needs some assistance from other microbes. There is a syntrophy (beneficial to both sides) relationship between the newly discovered ethane eating microbe Candidatus Argoarcheaum ethanivorans and Desulfosarcina which reduces sulfate to sulfide.
Connections: This article discussed some different ways microbes obtain energy. The newly discovered microbe is a methanotroph. Coupling the reaction of one microbe to allow for another microbe to use a unique energy source is not something we covered in class and seems to be a novel idea. We have discussed how the electron tower can predict what microbes use for energy in different environments, however it is cool to learn there are microbes that don’t seem to follow the pattern.
Critical Analysis: It is easy to forget that microbes work together and that each species doesn’t live in a vacuum. The idea that species can transfer molecules and electrons to each other’s benefit is a new idea for me. I was also curious about how we could harness the power of these microbes to break down similar molecular compounds that may cause harm in the environment. I think this story is scientifically accurate because the author explained the controversy between two ideas and provided evidence from research journals to explain each idea. The author talks more about the microbes that break down methane, butane and propane because more is known about them, however it did make it difficult to tell if the author was describing the new microbe or the properties of one already well known.
Question: Can these microbes be used to clean up chemicals and how can we harness the coupled power of microbial metabolism?
Cristina Mondelli
F03
My artwork was supposed to depict a bumblebee and a flower. I used M. luteus for the “yellow’ stripes on the bee and the center of the flower, but it did not grow very well. It might have needed more time in the incubator, but I was worried about the C. violaceum taking over and overcrowding the stripes, so I placed it in the fridge prematurely. The E. coli grew well, but got contaminated in the white of the wings. My flower was disappointing because I used S. marcescens which I expected to turn pink. For some reason, it failed to turn pink and left me with a white flower. Additionally, the M. luteus did not grow in the center of the flower.
While I did grow other pictures on the differential media, I liked how the TSA grew the best. The TSA was not extremely selective and was designed to allow the majority of culturable microbes to sustain life for lab purposes. TSA remains the same color regardless of what grows on it, even though the colonies themselves have color. It does not change color to indicate a change in the pH or only encourage a certain characteristic of microbe to grow. Because growing microbes on the TSA plate does not indicate any special characteristics of the microbes, it is not differential either.
Researchers identify immune culprits linked to inflammation and bone loss in gum disease
Wednesday, October 17, 2018
Vicki Contie and Dr. Catherine Evans
Summary: Researchers at the University of Pennsylvania and the National Institute of Dental and Craniofacial Research have discovered the reason behind inflammation in periodontitis in a joint study between mice and humans. An unhealthy oral microbiome may trigger T helper 17 cells to begin an immune and inflammatory response, even if proper oral care is being undertaken. Mice with knocked out Th17 genes were compared to a selection of patients who also were missing the gene. They found a lack of periodontitis in those missing the Th17 cells when compared with those in their age bracket.
Connections: We have not covered the immune system, but we have spoken about how important microbes are. These researchers are suggesting that without the proper diversity in an individual’s oral microbiome, other diseases can arise. We’ve talked about how plaque occurs from biofilm buildup, however there are good things in the mouth that work to keep inflammation and other diseases from occurring. This is just another example of how microbes really run the world.
Critical Analysis: This news release was very interesting because it paints the oral microbiome as the good-guy in this situation, even though we often think of it as the enemy. I felt the story was scientifically accurate because they explained how the researchers came to the conclusion they did and how the study was set up. The article was written in such a way as to describe what the researchers did in case anyone wanted to question their methods. I felt the article was well written, but it may be harder for individual’s without scientific backgrounds to understand. It was easier to read than a journal article, but harder to read than the average newspaper. This article did a good job communicating to the people it was aimed at: dental professionals.
Question: How does mouthwash and brushing your teeth affect an individual’s oral microbiome?
Castellaniella was discovered in 2006 as being separate from the genus Alcaligenes. The genus was named after Castellani who first discovered Alcaligenes in 1919 and contains two species C. defragrans and C. denitrificans.
Dr. Aldo Castellani (1874-1971) was born in in Florence, Italy where he studied and received his M.D. in 1899. Shortly afterwards, he was recruited by the Royal Society. While a member of the Sleeping Sickness Commission in Uganda, Castellani devised a new method for examining samples of cerebrospinal fluid of stricken patients. In 1903, he proposed the bacteria trypanosomes as the cause of sleeping sickness and named them specifically T. ugandensis. Due to the work of Castellani and members of the Royal Society’s commission, in less than five years Sleeping Sickness was discovered, its pathology and etiology presented, and became treatable through various means. In 1905, Castellani also discovered the presence of a spirochaete in yaws patients which was named “Treponema pertenuis Castellani‘ in a 1908 In
dian Medical Gazette. He remained in Ceylon for 12 years where he was appointed a position at Ceylon Medical School by the Secretary of State. In 1926 he established the School of Tropical Medicine at Tulane University and taught at Louisiana State University, and still had time to direct the Royal Clinic of Tropical and Sub-Tropical Diseases in Italy. In 1959 he co-founded the International Society of Dermatology and served as its president from 1960-1964. Before his death in 1971 at the age of 97, Dr. Castellani worked on four continents, was knighted, participated in three wars, described new microbial species, developed a new kind of mixed vaccines used by the Allies in World War I, and encouraged countless others in the pursuit of exploring tropical diseases.
Cipollaro, V.A. (n.d.). The history of the International Society of Dermatology. https://www.intsocderm.org/wp-content/uploads/sites/804/ISD%20Golden%20Jubilee_WEB.pdf
Kampfer, P., Denger, K., Cook, A.M., Lee, S.-T., Jackel, U., Denner, E.B.M., and Busse, H.J.. 2006. Castellaniella gen. nov., to accommodate the phylogenetic lineage of Alcaligenes defragrans, and proposal of Castellaniella defragrans gen. nov., comb. nov. and Castellaniella denitrificans sp. nov. International Journal of Systematic and Evolutionary Microbiology 56, 815-819.
N.A. 1971. Dr. Aldo Castellani, a Specialist On Sleeping Sickness, Is Dead. The New York Times 44.
Mitja, O., Asiedu, K., and Mabey, D.. 2013. Yaws. The Lancelet. https://doi.org/10.1016/S0140-6736(12)62130-8.
de Raadt, P. (2005). The history of sleeping sickness. World Health Organization: Fourth International Cours on African Trypanosomoses
The Etiology of Yaws. (1908). The Indian Medical Gazette, 43(3), 101.
Wright, A. (1999). Twentieth Century Impressions of Ceylon: Its History, People, Commerce, Industries, and Resources: Asian Educational Services.
Article and link: https://www.sciencedaily.com/releases/2019/01/190115121103.htm
Published: January 15th, 2019
Summary- This short article introduces two new fungal species which inhabit glacial ice on Ellesmere Island. The author also begins to explain how their habitat is being affected by climate change and what further research is being performed.
Connections- While we have not covered much yet, I did find it interesting that the researchers proposed the name Mrakia hoshinonis after Tamotsu Hoshino, a polar region fungi researcher from the National Institute of Advanced Science and Technology. The other species is proposed to be called Vishniacozyma ellesmerensis after the island where it was discovered. The naming process reminded me of the Epithet assignment. These microbes also live in cold environments, which means they could be categorized as psychrophiles.
Critical analysis- I found this story interesting because it shows just how much we still don’t know about microbes in general, let alone the ones that live in extreme environments. I do not think there was enough information in this story to say it is scientifically accurate or not. The author does not talk too much on how the researchers found and identified the species. Because of our lack of knowledge, it is easy to see why two new species could be found in one small area. The author went on a tangent in the article to talk about climate change. And while it had to do with further research, I felt like it stole the show from the idea of new species in glacial ice and what the implications are of the discovery. The public may not recognize all the different aspects that go into discovering a new species, and they might get caught up in the scary climate change drama.
Question- What can we learn from microbes that live in extremely cold environments?
Hi everyone! My name is Cristina Mondelli and I am a senior biology student. I plan on starting a dental practice in Fairbanks after attending dental school, which will enable me to travel and participate in medical missions. I recently returned from spending time in the Philippines teaching children about dental hygiene and playing soccer, and I had a blast! My hobbies include anything soccer related, teaching science to kids, and exploring the outdoors. I am excited to learn more about how microbes affect our oral health so I can share that knowledge with others. I am looking forward to an exciting semester with you all!
