Bacteria harness viruses to distinguish friend from foe

April 16, 2019

https://www.sciencedaily.com/releases/2019/04/190416132121.htm

Summary- Researchers have discovered that bacteria found in the gut use a virus to self-recognize using the virus to self identify.   Thomas Wood of Pennsylvania State University one of the senior authors found a demarcation line was formed when Escherichia coli K-12 strains were near each other, but not when identical clones were near each other.   They found that prophage CPS-53 and one of its proteins, YfdM, were required for the demarcation line and that CPS-53 is essentially inactive in cell lysis and phage-particle production causing them to believe this was the reason for the difference.

connection- We have discussed bacteria and viruses in detail throughout the semester.   I thought it was interesting how the viruses that attack these bacteria are being used to keep itself safe and recognize itself.

critical analysis- I thought the subject was very interesting and was something that had not been discussed previously.   I did think the article was written for people with a scientific background and that some of the details would be unknown to someone without some microbiology background.

quesiton- Are there other bacteria in the body that use this same technique?

Bacteria That Eat Drugs Could Help Solve the Antibiotic Resistance Crisis

Researchers design bacteria to gobble up antibiotics in the environment, before microbes have a chance to turn deadly.

By  Jonathon Keats|Thursday, November 08, 2018

Link: https://discovermagazine.com/2018/dec/the-antibiotic-eaters

Summary: Antibiotic resistance has been around for a long time; it has even existed in nature long before humans contributed more antibiotic resistant bacteria. In the year 2007, a postdoctoral researcher in the Harvard University lab of George Church named Gautam Dantas researched the bacteria that are capable of consuming and using antibiotics as a nutrition source. It was found that bacteria evolved to resist beta-lactam which is supposed to weaken their cell walls but by producing an enzyme that breaks the ringlike part if the molecular structure when it is exposed to penicillin. There is still a lot more for scientists to learn about why bacteria engage in the behavior of eating substance that are meant to kill them.

Connections: When it comes to penicillin, we learned that it also targets the peptidoglycan in bacteria cell walls, it binds to microbial tanspeptidase enzyme so it can’t cross-link peptidoglycan. We also learned in class when taking about penicillin that it will not kill Archaea because they don’t have peptidoglycan. There is also a huge problem with over prescribing antibiotics in humans and livestock that is contributing to the more antibiotic resistant bacteria that are out there.

Critical analysis: What I found interesting is that some bacteria have evolved in a way that certain antibiotics that are made to kill them, becomes a nutrition source for them. It is amazing how this can come about but it is also quite concerning because it might be even harder to find other alternative medicine in the future. However, with the increasing amount of inavation in technology, like whole genome sequencing can help with this huge problem that is still on going.

Question: What kind of other ways in the future that could help with the problem of antibiotic resistant bacteria?

Summary- Mohammed Saleem, a professor from Purdue, has found a new method that can treat infections by antibiotic resistant bacteria. The method involves treating the infection with blue light, which strips the bacteria of a pigment necessary for survival in the host. By removing this pigment, the bacteria are weakened to a point that traditional mild antiseptics. This has been found to be effective in mice infected with MRSA, and the researchers are looking forward to human trials.

connections- We have learned that antibiotic resistance is a major area of research of monumental importance. Because blue light is not toxic to the host, it is selective for the pathogen and is an easily accessible method of treating infections on the skin.

critical analysis- It is not explained exactly why the bacteria need the pigment, or how the blue light washes this pigment from the cell. The blue light does not kill the cell, and the use of “mild antiseptics” are still necessary. Depending on what the antiseptics are, this could still contribute to antibiotic resistance.

question- What does the pigment do to help the bacteria live in the host body?

https://www.purdueexponent.org/campus/article_b4027a8b-01ad-5ea9-b4e9-fbff0cc00fbf.html

If you have kept up with my “microbes in the news” posts, you’ll probably notice a theme at this point. I’m very interested in the gut microbiome. I think this is largely just because I’m a health geek and strive to fuel my body as efficiently as possible. But with that said, also how junk food and preservatives affect the gut biome, because trust me, I still get my fair share.

“UH Maui College research finds that food preservatives kill beneficial bacteria found in humans” UHM Nov 2017

Summary:

The study began out of interest for the increased number of those with food allergies, obesity, and metabolic disorders. Trying to understand what in our environment is causing this was the driver for the study. The article talks about how there is a correlation between gut microbe disturbance and consumption of common preservatives. The study showed that the gut microbes are killed or inhibited after inoculated with common preservatives in the same concentration regarded as safe by the FDA.

Connections: This is exactly what we learned about when talking of the human microbiome.

Critical analysis: Being that this study came from a university, I feel it is fairly dependable. This article seems to have been published before the publication of a primary literature paper, but otherwise interesting to know the correlations.   I also feel the article did a good job of giving the information to the public, as it did not draw any conclusions.

Question: Can we expect to gut microbes to evolve to process preservatives?

AS SUBWAY COMMUTERS MINGLE, THEIR MICROBES DO TOO

As Subway Commuters Mingle, Their Microbes Do Too

Summary: A research group in the University of Hong Kong wanted to get a holistic view of how many microbes interact with humans in a city. They specifically studied the Hong Kong metro system which provided the team with a way to look at microbe populations throughout the city. About 5 million people are riding the metro every day. In their study, they had volunteers ride the metro during the morning and during the night. They collected bacteria by telling the volunteers to hold on to the handrails and then swab their hands (palms) after they got off the metro. The goal of their study is to understand what microbes on the metro transfer onto the riders. After the samples underwent DNA sequence analysis they discovered that the microbes the riders encountered were very dependent on time. They discovered that the morning riders were mostly exposed to microbes that belonged to the same environment surrounding different metro lines. The evening riders had a mixture of microbes some also belonging to different metro lines but the majority belonged to microbes that live on human skin. Through their study, they discovered that different metro lines had distinct populations of microbes in the morning but in the evening the populations had blended together.

Connections: During lecture, we have talked a lot about how we have an immune system to protect us from microbes. Specifically, we have an innate (non-specific) immune system which consist of physical barriers such as skin and hair. A lot of the microbes found on the hands of the volunteers belonged to a mix of different microbes found in different metro lines and microbes that are found on the human skin. Without these physical barriers a lot of people will be exposed to the microbes and could potentially get sick. We have also talked about ways of disinfecting places to prevent the spread of microbes. Even though, the metro employees were cleaning the train rails that people touched throughout the day, the commuter traffic through out the day were spreading microbes along with it. So, although the rails were being cleaned through the day the microbial spreading was still occurring.

Critical analysis: We already know that microbes are everywhere. The goal of this study wasn’t to scare the metro riders. They want to educate the public that might not fully understand what microbes are, that they are everywhere and they can spread quickly. Especially in public places, through the study they wanted to help commuters understand what they can do to protect themselves and reduce the spread of bacteria.  Many people grab these rails and then might rub their eyes or eat something without washing their hands. I think this study is important so people have better hygiene after being in public spaces. Meaning perhaps washing their hands as soon as they can or having hand sanitizer handy when they can’t wash their hands.

Question: I wonder if the rails were being cleaned though out the day for the purpose of the experiment only. Are they cleaned on a regular basis though-out the day when it’s not for   study? If not, would they have potentially found other more harmful bacteria?