A2: Microbes in the News

Article and link: Florida Tests Bacteria-Infected Mosquitoes to Kill off Bugs. USNews Associated Press. April 19, 2017. Link:  https://www.usnews.com/news/best-states/florida/articles/2017-04-18/florida-tests-bacteria-infected-mosquitoes-to-kill-off-bugs

Summary: Bacteria-laden mosquitoes have been released in a segment of Florida in order to find how it affects the local wild mosquito population.  These mosquitoes mate with wild mosquitoes in the area, but their offspring are unable to survive.  Other methods are being created such as genetically modifying mosquitoes whose offspring can’t survive outside a lab and introducing them to the population.  All of this is supposed to be utilized as a cheaper form of pest-control.  Some people don’t wan’t GMOs of any kind in their area due to philosophical views.

Connections: We have studied the Zika virus in class, which is carried by mosquitoes.  This pest control is aimed to stop viruses such as Zika from being transferred as much.  Also, we have learned about bacterial pathogens in class.

Critical analysis:  I think this story is fascinating.  If I were trying to control mosquitoes, probably the last thing I would do is say “Add more mosquitoes to the area”.  But, this was done with some thought behind it.  If the infected mosquitoes highly outnumber the wild population, this will lead to less percentage of wild population males from mating and seems like a good way to limit population totals over time.  I feel the story is scientifically accurate, but I wonder if there are more flaws than most people would perceive.  What if the wild population recognizes these mosquitoes and don’t mate with them?  What if the infected mosquitoes can’t fertilize the wild mosquitoes so the wild female will continue to mate until fertilized by a fertile male regardless.  How often do you have to reintroduce these populations?  I think the article was written well, but I wish it delved into some of these possible questions addressed to provide me with a better idea of how feasible this is on a large scale.  I think it did a good job of communicating science because it picked a hot topic such as the Zika virus to bring to light new genetically modified capabilities as well as other means of pest control that the public is not used to.

Question: The article mentioned that the research team is trying to introduce the infected male mosquitoes at a rate of 7:1 compared to the wild males currently existing.  What methods are usually used to measure mosquito populations in such a wide open area?

A2: Microbes in the News

Article and Link: 3.77-billion-year-old fossils stake new claim to oldest evidence of life.  Science the magazine. March 1, 2017. Link: https://www.sciencemag.org/news/2017/03/377-billion-year-old-fossils-stake-new-claim-oldest-evidence-life

Summary: New fossils may provide evidence that life on Earth existed 300 million years prior than what we can prove today.  Structural and chemical signatures show that iron-oxidizing bacteria may have formed features caught in the 3.77-billion-year-old fossils.  Other scientists, aren’t so optimistic about the findings.

Connections: We’ve went over in class the two ideas that life formed at the surface or below the surface.  In this article, these fossils show that deep-sea microbes may have existed before the current 3.4-billion-year-old stromatolites, which were near or on the surface.  Also, it connects to energy-procuring strategies of microbes such as chemolithotrophy found in this article.

Critical Analysis:  I found it interesting that the evidence that  the article is based on are fossilized structures that are easy to miss with the human eye, and how it has caused such a debate due to the implications of accepting that life conclusively existed 300 million years prior to what we can prove at the moment.  I think the article was scientifically accurate because it provided both sides of the story.  The backers of the evidence claim that not only are the structures very similar to what occurs at modern hydrothermal vents by microbes, but that the chemical signatures also point toward life.  The naysayers argue that such characteristics found in such ancient rock are hard to use as certain evidence due to the amount of changes the rock has undergone through time that may lead to inaccurate findings; they also argue that it isn’t impossible for abiological processes to create similar structures.  I believe it was written well.  Clear, concise sentences and not very long in length to lose the reader’s interest in the minutia.  For that reason, I also thought it did a good job of communicating science to the public.  It gave information on a contested issue relevant to most people as a whole in a snack-size chunk that wouldn’t turn people away from reading the information.

Question: A stromatolite formation found in Australia is currently given the nod as the oldest proof of life currently.  At the time it was discovered, how long did it take the gain this level of acceptance?

 

A2: Microbes in the News

Title: Microbes Set the Stage for First Animals

Date:  April 8, 2017

Authors:  Amanda Doyle

Link:  https://www.space.com/36403-microbes-set-stage-for-first-animals.html

Summary:  Several researchers  have found what they describe as “…odd creatures, most of which have no evidence of a circulatory or digestive system…”. These creatures existed around 541 million years ago during the Cambrian Period. These creatures, the scientists argue, might not have been animals at all.

Connection:  We have talked about the eveloution of life on Earth, from microbial life to multicellular life. Somewhere between singlecelled life and multicellular life, these creatures showed up which we thought might have been the ancesters of animal life; but other kinds of life might have existed at the same time.

Critical Analysis: This article did a pretty good job explaining the science behind these researchers findings. They explain how the enviroment changed over time and alowed these creatures to evolve along with others.

Question: Do you think these microbes could  still be around today in another form? Perhaps like the colonial Portuguese man o’ war?

A2: Microbes in the News Assignment

Article: NASA Astronaut Kate Rubins Talks About Microbes

Date:  August 3, 2016

Author:  Kate Rubins, NASA.gov Video (youtube channle)

Link:  https://www.youtube.com/watch?v=r33F8OLtGDw

Summary:  NASA Astronaut Kate Rubins talks about upcomming experiments on the Internatinal Space Station. These include understanding the microbiome of the human body and the microbiome of the spacestation itself. The astronauts can do this via protible DNA sequencers among other exciting new mirobial research equipment.

Connections:  This vidio got me excited about the experiments being conducted on bord the ISS. They will be studying things related to subjects we’ve learned in class such as; microbial gene expression in microgravity, human immune system, bone and muscle system changes due to microgravity, understanding the human and spacestations microbiomes. They can do this with protable DNA and RNA sequencers. This is to connect the effects of spaceflight (microgravity, increased radiation, recycled atmosphere among others) back to the microbiome on Earth and other planets.

Critical analysis:  I really enjoyed this vidio and it got me excited for the upcoming experiments the astronauts on the ISS will be conducting.  I learned that DNA sequencing can be done with a device “as big as a cellphone”, which is very exciting for the future of microbiology. I also really enjoy NASAs vidios and articles, as I feel they do a great job expressing science so everyone can understand it.

Question:  Would you want to go to the ISS knowing you’ll be potentially shairing microbiomes with your colleagues more rapidly then normal? This would be due to the tight quarters plus the recycled atmosphere and water systems.

A2: Microbes in the News – The ‘Dark Matter’ of the Microbial World

The ‘Dark Matter’ of the Microbial World

Sarah Zhang, March 7, 2017, The Atlantic

https://www.theatlantic.com/science/archive/2017/03/archaea-sequencing-challenges/518535/

Summary: Archaea have been historically understudied but they actually are an important part of the human microbiome. Since the genomes of archaea are widely unknown the use of common primers based on 16S rRNA gene sequencing has failed to identify the diversity of archaea that are present in the microbiome of primates, including humans. When sequencing was done on feces samples using archaea primers instead of universal primers, many more archaea species were identified –  in humans the difference was 37 species with arcane primers versus 1 species with universal primers. The most common archaea species found were methanogens. This difference is most likely due to the fact that universal primers are made with common bacterial species in mind. With metagenomics this scenario is likely to change in the near future –  we are now able to sequence the entire genomes of the species found in our samples so it is likely that the extent to which archaea are present in primates’ microbiomes will start to be more understood.

Connections: In class we briefly covered Archaea. This article cites an interesting cycle – the microbes that we cannot culture  are not studied as often. We base future studies on what we know (culture methods, genomes) so scientists tend to expand more on previous knowledge rather than studying completely new and unknown species. I believe that this will change soon, but when primers were the main tool in sequencing genomes I could see how this would happen. Scientists simply did not have enough information and tools to fully characterize Archaea.

This article did a good job of communicating the extent to which Archaea are not fully understood. They probably should have explained more about the fact that Archaea are not a type of Bacteria even though they are prokaryotes.

Question: What is the proportion of Archaea in the human microbiome? Are they essential in nutrient absorption and even production?

A2 Microbes in the news: Fungal infection ‘threat’ to human health

Fungal infection ‘threat’ to human health

James Gallagher, BBC News, July 5th, 2016

https://www.bbc.com/news/health-36702215

Summary: This article aims to describe the extent to which fungal infections can be pathogenic to humans. Often when people think of fungal infections, they may not necessarily consider that these type of infections kill one million people per year. Also, there are no vaccines available for fungal infections. Three major groups of fungi are responsible for the infections. People that are immunosuppressed are most vulnerable to these infections.

Connections: Fungi are eukaryotes, which means that they share many cellular mechanisms with the eukaryotic hosts that they infect, such as humans. This explains in part why it is so difficult to make vaccines against and treat fungal infections. Since antibiotics rely on differences between the pathogens and host for their targets, if the pathogen and host are similar, there are fewer cellular mechanisms available for the antibiotic to target.

Critical analysis: I though that the numbers in this story were interesting. I was not aware that approximately 1 million people are killed every year by fungal infections, and that there are three main categories of fungi that are responsible for these infections.

Question: Do any vaccines against fungal infections exist? What is their mechanism?

Getting antibiotics as a baby may have lasting effects on brain, behavior

Getting antibiotics as a baby may have lasting effects on brain, behavior

https://arstechnica.com/science/2017/04/getting-antibiotics-as-a-baby-may-have-lasting-effects-on-brain-behavior/

Published: April 5, 2017 at ArsTechnica

This article looks at a few different articles having to do with gut microbiome and their effects on the human brain in terms of behavior.   The main focus is a later paper in a series which looks as the exposure of baby mice to antibiotics given before and after birth.   The mice were split into two groups were one had penicillin introduced through the mother while in the womb and to themselves when they were born, with a later group added in which mice had the penicillin as well as were given a probiotic.   The group that had the penicillin had 42 percent of the population that were aggressive as opposed to the 9 percent in the control group.   Additionally, the antibiotic group appeared to be less social and a little less anxious.   The probiotic mice also had a thinner blood-brain barrier.   The group with the probiotics introduced had some of the effects of the antibiotic blocked.

Being that we talk a lot in class about how helpful a good gut microbiome is and how bad it is to overuse antibiotics —especially those that are more broad-spectrum, the contents of this article are no real surprise to me.   Even talk of cytokines being increased in the brains of exposed mice is a concept that I can understand thanks to learning about then with the immunology portion of class.

Overall, the article does a pretty good job at telling the story of the paper to the general public.   It goes as far as to include a section to discuss some of the limitation of the discussed study, such as the fact that the period of exposure to penicillin was quite long as well as the fact that the exposure before and after death was not differentiated in the study.   My only issue with the paper was that in one of their background statements, they say that, “gut microbes have been caught making most of the neurotransmitters our brains use to regulate themselves,’ but yet the link they provide leads to a paper that seems to more-so talk about the way that our neurotransmitters will influence the gut microbe, not vice versa (though the full paper was a paid paper and not free to view).

Question:   If there is a chance for the probiotics to help block the effects of the antibiotic use in infancy, would it be possible for probiotics to be used in a longer trial such that they eventually reverse the behavior issues that arise from the use of antibiotics?

Ancient Microbes Found Hidden in Crystals

Microbes survived inside giant cave crystals for up to 50,000 years

ScienceNews

February 18, 2017

https://www.sciencenews.org/article/microbes-survived-inside-giant-cave-crystals-50000-years?mode=topic&context=79

Summary:

Microbes have been found inside giant crystals in caves in Chihuahua, Mexico. These microbes could have survived there for tens of thousands of years undisturbed. They are not like any other genus known currently and after genetic testing from microbial communities in the caves researchers do not think that the crystals were contaminated by other microbes since the crystal’s formation, confirming the age estimates for the microbes.

Connection:

This goes hand in hand with the extremophile unit. These microbes survived for thousands of years without any contact with the outside world. The microbes could have also made spores since it is unknown if they were dormant for the entirety of thier time in the crystal or for a portion. Whatever the case researchers were able to wake the microbes up and study them in lab.

Critical Analysis:

I found it intersting when the article was talking about astrobiology becasue before this class I had no idea that was a field. Now that I know about it I can see the need in such a field. I also think that it is interesing how these microbes are like no other on Earth and this could help us find life on other planets.

Question:

How will NASA insure that no Earth microbes will make it to other worlds where they are studying life?

A2: Microbes in the News – Amoeba can help kill bacteria protected by biofilm

Article:  Study finds amoeba “grazing,’ killing bacteria usually protected by film (April 17, 2017)

Source: University of Wisconsin-Madison

Study finds amoeba “grazing,” killing bacteria usually protected by film

Summary:

An Amoeba species called Dictyostelids  is capable of penetrating biofilm in order to eat the bacteria within. Bacteria tested were  Pseudomonas aeruginos,  Pseudomonas syringae,  Klebsiella oxytoca and  Erwinia amylovora.  All these bacteria are capable of creating biofilms and were harmful to humans or plants. This also opens up further studies of methods of killing bacteria without resorting to antibiotics, which the bacteria may grow resistances to.

Connection:
We’ve learned about how certain microbes can create biofilms to protect and help with survival. This article is about how we can get around that. Also my isolate happened to be a bacteria capable of creating biofilms (S.epidermidis)

Critical Analysis:

Most of the article was regarding the scientists’ steps in finding out about this amoeba rather than the actual science behind it. However, it did use many quotes by the scientists so it did give assurances on the accuracy of the report.

Question:

What is the molecular mechanism of how the amoeba can “eat” biofilm?

Will using amoeba to kill bacteria be safe for humans/plants in vivo?

 

A2: Microbes in the News — How gut bacteria change cancer drug activity

Article:

How gut bacteria change cancer drug activity (April 21, 2017)

Source: Medical xpress

https://medicalxpress.com/news/2017-04-gut-bacteria-cancer-drug.html

Summary:

University College London (UCL) did a study using  Caenorhabditis elegans has a model organism to study the effect of genetics, diet and chemical make up of the gut effect the cancer drug  fluoropyrimidines. Fluoropyrimidines is a colorectal cancer drug that kills cancer cells by preventing DNA replication. They used the  Caenorhabditis elegans worm because their digestive tract can be a model of human digestive tract. They screened total of 55,000 different conditions and found that certain bacteria in the gut can improve the effectiveness of the drug by assisting in activating the drug as well as allow the body cells to uptake the drug more.

Connection:

We’ve learned about the natural human flora and how they affect us. This shows an example of how bacteria can affect drugs that we take.

Critical Anaylsis:

Although the article was interesting and concise, they really did not go into details of the experiment. For example, what sort of conditions did they test exactly.

Question:

What conditions did the screen consider? What bacteria exactly? How did the bacteria improve drug intake (Molecular mechanism)?