I made this video (below the fold) to illustrate the steps involved in making a phylogenetic tree. The basic steps are to: Build a data set Align the sequences Make a tree In the class that I'm teaching, we're making these trees in order to compare sequences from our metagenomics ...
Antibiotics are molecules of biological warfare. Produced by bacteria and some fungi, in response to extracellular signals, antibiotics represent a diverse group of compounds that inhibit bacterial growth at different points and different stages of the life cycle. We will get around to antibiotic resistance, but in these few words ...
This is a multi-part series on antibiotic resistance in bacteria. Eventually, we'll reach the ways in which bacteria develop antibiotic resistance, but before we get there, we'll spend a little more time on antibiotics themselves. What have we learned so far? 1. Antibiotics are natural products, made by bacteria and ...
The wind storms and heavy rains that hit Seattle a few years ago, and flooded the Battery Street tunnel, demonstrated why a bypass mechanism can be a helpful thing - for both bacteria and motorists. When the weather is nice, I bike to work. But when the weather gets bad ...
What's the difference between a synthetic drug and an antibiotic? Sometimes there's no difference at all. Let's take a look at chloramphenicol and couple of pencillins. Chloramphenicol kills many different kinds of bacteria by interfering with their ability to make new proteins. Here's a point where language gets tricky. Originally ...
Do other organisms make antibiotics? As far as I can tell, most of the commercially produced antibiotics are made by bacteria, fungi, and a bit chemistry (more on that in a moment). It appears, however, that compounds with antimicrobial properties are made by just about everything. Just to make things ...
Blogging from the NW ASM branch meeting, part II Yesterday, I wrote about the some of present (and future) methods that are (or will be) used in clinical labs to identify pathogenic microbes. In these next two posts, I want to describe the talks I attended on antibiotic resistance, from ...
This is third video in our series on analyzing the DNA sequences that came from bacteria on the JHU campus. In this video, we use a pivot table to count all the different types of bacteria that students found in 2004 and we make a pie graph to visualize the ...
Do different kinds of biomes (forest vs. creek) support different kinds of bacteria? Or do we find the same amounts of each genus wherever we look? Those are the questions that we'll answer in this last video. We're going to use pivot tables and count all the genera that live ...
Metagenomics is a field where people interrogate the living world by isolating and sequencing nucleic acids. Since all living things have DNA, and viruses have either DNA or RNA, we can identify who's around by looking at bits of their genome. Researchers are using this approach to find the culprit ...
I began this series last week with a question about a DNA sequence that was published and reported to be one the first beta-lactamases to be found in Streptococcus pneumoniae. Mike has a great post about one of problems with this paper. I think the data themselves are awfully suspicious ...
Here's a fun puzzler for you to figure out. The blast graph is here: The table with scores is here, click the table to see a bigger image: And here is the puzzling part: Why is the total score so high? If you want to repeat this for yourself, go ...
During the past few Fridays (or least here and here), we've been looking at a paper that was published from China with some Β-lactamase sequences that were supposedly from Streptococcus pneumoniae. The amazing thing about these particular sequences is that Β-lactamase has never been seen in S. pneumoniae before, making ...
One time I was watching a football game on TV and they had a short quiz, called "You make the call" or something like that, and you had to watch a play and pretend to be a referee. A short video clip showed football players falling over each other. Then ...
The University of Nevada in Las Vegas is looking for a few good undergraduates to come do research this summer in environmental microbiology. Environmental microbiology goes way beyond hot springs bacteria and Yellowstone Park. At UNLV, you can do science in the desert. It almost makes me wish I was ...
Decan Butler, the Reveres, and Nature have written that verdict is in. The scientific evidence has been shunted aside. The nurses and doctor who traveled to Tripoli on a humanitarian mission have been sentenced to death. There is still a chance, but it seems to be slim. Two articles in ...
I think all of us; me, the students the OO advocates, a thoughtful group of commenters, some instructors; I think many of us learned some things that we didn't anticipate the other day and got some interesting glimpses into the ways that other people view and interact with their computers ...
There are five ways that I know of that allow bacteria to escape death. I call these t he five paths to antibiotic resistance 1. Persistence is resistance: Most antibiotics kill by acting on the metabolic pathways needed for bacteria growth. Ironically, bacteria can survive by not growing. Read more ...
It looked like just any other rainy Saturday morning in the Pacific Northwest, but no, this Saturday was a day for microbiology. Reluctantly, I crawled out of my warm bed and headed over to the University of Washington to attend a meeting of the Pacific NW branch of the American ...
Goodbye desktop, we're off to see the web. Both my students and I have been challenged this semester by the diversity of computer platforms, software versions, and unexpected bugs. Naturally, I turned to the world and my readers for help and suggestions. Some readers have suggested we could solve everything ...
I read about this in Bio-IT World and had to go check it out. It's called the Genome Projector and it has to be the coolest genome browser I've ever seen. They have 320 bacterial genomes to play with. Naturally, I chose our friend E. coli. The little red pins ...
HealthMap is a great site that could be an excellent resource when teaching a biology, microbiology, or health class. Not to mention, I can picture people using it before they travel somewhere or even just for fun. I learned about HealthMap awhile ago from Mike the Mad Biologist, but I ...
Cofactor Genomics is offering to sequence a genome for a few classes for free using Next Generation DNA Sequencing technology (either Illumina GA or via AB SOLiD). Quoting from their site: Cofactor will ask course organizers for a 1 page description of how their ~700Mb sequencing project could be used ...
The other day, one of my commentors wrote that "a well-informed sixth-grader should be able to distinguish MRSA from E. coli". Well, here's a nutrient agar plate with some of the bacteria that we isolated from a local creek last fall. We identified our bacteria by sequencing the 16S ribosomal ...
Are viral and fungal infections always a bad thing? Maybe not if you're a plant. In fact, if you're a plant trying to grow in the hot (65°; C) soils of Yellowstone National Park, you're going to need all the help you can get. A new study by Márquez, et.al ...
That's how new life forms are created every day in the wild, folks. Human researchers of course have added a few twists on the theme. If we can't induce bacteria or animal cells to collect new bits of DNA on their own, we turn to electroshock therapy. With plants.... aw ...
I'm teaching an on-line bioinformatics course this semester for Austin Community College. They are in Texas of course, but I am in Seattle. This presents a few interesting challenges and some minor moments of amusement. Today, the school sent all the faculty emails telling us to stay home if we're ...
If you like cool and unusual photos be sure to take a look at the 2008 Nikon Small World competition site. You can view lots of lovely pictures of things found under a microscope and vote for your favorite ones. You don't even have to focus the microscope! One of ...
If you're old enough or you've taken microbiology, there's a chance that sometime in your life you heard of Legionaire's disease. This disease was caused a bacteria that inhabited the air conditioners in a hotel where several veterans held a conference. Naturally, it was the microbiologists who collected samples of ...
The 2009 Summer Research Experience for Undergraduates in Environmental Microbiology at UNLV is now accepting applications. This NSF supported program provides undergraduates with an opportunity to perform independent research under the guidance of a faculty mentor. Students will collaborate with faculty mentors in developing and carrying out hypothesis-based projects on ...
Would you like to have some fun playing with chromatograms and helping our class identify bacteria in the dirt? This quarter, my bioinformatics class, at Shoreline Community College, will be working with chromatograms that were obtained by students at Johns Hopkins University, and graciously made available by Dr. Rebecca Pearlman ...
In the class that I'm teaching, we found that several PCR products, amplified from the 16S ribosomal RNA genes from bacterial isolates, contain a mixed base in one or more positions. We picked samples where the mixed bases were located in high quality regions of the sequence (Q >40), and ...
DNA sequence traces are often used in cases where: We want to identify the source of the nucleic acid. We want to detect drug-resistant variants of human immune deficiency virus. We want to know which base is located at which position, especially where we might be able to diagnose a ...
The next time you bite into a crisp juicy apple and the tart juices spill out around your tongue, remember the honeybee. Our fall harvest depends heavily on honeybees carrying pollen from plant to plant. Luscious fruits and vegetables wouldn't grace our table, were it not for the honeybees and ...
The simple fact is this: some DNA sequences are more believable than others. The problem is, that many students and researchers never see any of the metrics that we use for evaluating whether a sequence is "good" and whether a sequence is "bad." All they see are the base calls ...
Hey students: if you are looking for a summer internship in marine metagenomics and you can get your application together before June 16th, Jonathan Eisen posted information about an open position on his blog. It also looks like he's looking for post-docs (see the side bar on the right of ...
For the record: Chlamydia is NOT a virus. I am bummed. I like the little MicrobeWorld radio broadcasts, and the video podcasts are even more fun. But I was perusing the archives and I found this: I could ignore this if it came from a different source, but MicrobeWorld is ...
Bacteria can cause other epidemics, why not obesity? Is there a relationship between our body weight and our bacterial inhabitants? Two reports in Nature (1, 2) suggest that bacterial populations differ between people who are obese and people who not, and that the bacterial inhabitants of their guts, may be ...
We had a great discussion in the comments yesterday after I published my NJ trees from some of the flu sequences. If I list all the wonderful pieces of advice that readers shared, I wouldn't have any time to do the searches, but there are a few that I want ...
A few weeks ago, I wrote about visiting the Dead Sea Scrolls exhibit at the Pacific Science Center and learning how DNA analysis is being used to help put pieces of the scrolls together. One of the mysteries that was discussed in the exhibit was the question of whether the ...
We have lots of DNA samples from bacteria that were isolated from dirt. Now it's time to our own metagenomics project and figure out what they are. Our class project is on a much smaller scale than the honeybee metagenomics project that I wrote about yesterday, but we're using many ...
What happens when a group of streptococci stick to cells in your throat and start to make toxins? Your body fights back by making clones. The animated video, Fighting Infection by Clonal Selection, from Etsuko Uno and Drew Berry is so good that if I didn't know better, I would ...
A few years ago, the General Biology students at the Johns Hopkins University began to interrogate the unseen world. During this semester-long project, they study the ecosystems of the Homewood campus, and engage in novel research by exploring the microbial ecosystems in different sections of the campus. Biology lab students ...
When purified, it glows with an unearthly light. You can't go "chemical free" and try to escape it. It's part of our bones and it forms the backbone of our DNA. A tool for good, a tool of war, essential for gardening, and infamous as a pesticide; phosphorus is truly ...
What do malaria, sleeping sickness, yellow fever, and dengue virus have in common? Sure, they're all tropical diseases, but there's something else. All of these diseases have some kind of insect vector. image from the Public Health Library tags: , At one time, I thought it was merely a matter ...
Microbiologist develop some strange habits when it comes to food. Some take a fatalistic approach. They reason that microbes are everywhere, we're going to die anyway, we might as well eat dirt and make antibodies. You know these people. They quote things like the " 10 second rule" when food ...
Okay OpenOffice fans, show me what you can do. Earlier this week, I wrote about my challenges with a bug in Microsoft Excel that only appears on Windows computers. Since I use a Mac, I didn't know about the bug when I wrote the assignment and I only found out ...
I'm sure everyone else thinks the big news today is the announcement by the Washington State Health department requiring hospitals to report MRSA cases to the state. I think the cool news is their on-line database. We'll get to that a bit later. What is MRSA? MRSA stands for methicillin-resistant ...
Hospital cases of methicillin resistant Staphylococcus aureus (MRSA) have risen 33-fold during the past ten years in Washington state, yet our hospitals fail to identify or track cases in a systemic fashion ( Seattle Times). The Seattle Times began a three-part investigative report today describing the rise in MRSA incidence ...
Trade publications; such as catalogs, technical bulletins, and web sites; are a valuable source of information for students in biotechnology-related courses. Not only do catalogs and technical publications provide current information, but they also contain a wealth of useful facts and physical constants that biologists need on-the-job. Further, using catalogs ...
