Adding Microbial Friends to My Network - Part One

According to a recent survey, 91% of Americans own a cell phone. These phones accompany us everywhere. Cars, workplaces, malls, parks...even the bathroom. All of these places are teeming with microbial life, and our phones serve as a surface for microbial colonization. Surf the internet on the subway, take a couple photos at a pumpkin farm, or check Facebook on the toilet (...ew...), and you will likely acquire some microbial souvenirs on your phone.

Although most of these microbial hitchhikers won't cause you any harm, there are concerns about the spread of disease-causing or antibiotic-resistant bacteria on phones. For example, researchers in Scotland found 84% of hospital patients' phones were colonized by microbes, including pathogenic bacteria such as Staphylococcus aureus.

Most studies investigating microbial colonization of phones examine a single time point. But how does microbial colonization of phones proceed over time? I recently got a chance to find out! Two weeks ago, my cell phone of 6 years suffered a fatal fall (i.e., I dropped it). I dutifully reported to my local wireless store and left with a brand new smartphone. That night, I realized my old phone's misfortune was a golden opportunity for a longitudinal study of microbial colonization of mobile phones! 

With a little more foresight, I would have tromped into the store with sterile cotton swabs to sample my new phone straight out of the box. Alas, I didn't think of it until later. But I did sample my phone within 24 hours, so the results can serve as a good "baseline" for future comparisons.

The details
Awesome lab tech Lari and I used two kinds of agar plates: (1) lysogeny broth (LB) agar and (2) trypticase soy agar (TSA) with 5% sheep's blood. We used sterile cotton swabs soaked in phosphate-buffered saline to swab the front and back of the phone (in halves). We then spread the swabs over the agar and incubated the plates at 37 degrees Celsius (98.6 degrees Fahrenheit, which is internal body temperature).

The results

Here are the plates after about 36 hours of incubation.

LB agar - front of phone

In the Trenches: Cover Letters for Undergrads

Although the main purpose of my blog is to share fascinating microbiology, I also have interests in science education and the scientific enterprise itself. I thought about posting in a separate place on these topics, since it's a bit of inside baseball, but in the end I decided to include these posts here as a feature called "In the Trenches". Here's the first in the series, written for undergraduate students who are interested in doing research with a professor during their time in college. 

Standing out in a crowd: tips on writing cover letters for undergrads applying to lab research positions

There it is, stapled to the bulletin board in the hallway. A job announcement advertising the perfect research opportunity for you! It's a chance to work in a professor's lab, doing experiments on a fascinating topic. If you're interested in pursuing a career in science, conducting research with a faculty member during your undergraduate career is one of the best ways to develop your scientific skills and gain important experience. But, your classmates know this, too. How can you set yourself apart in a crowd of eager applicants? Write a good cover letter! Based on my experience hiring students for lab research positions, I’d like to offer a few pointers to help you craft a strong and professional cover letter for your application.

Most likely, the job announcement is a few brief sentences describing the project, a list of desired qualifications and a request to submit a resume to a particular person. Something like this... 

A work study position is available in the laboratory of Dr. Sarah Stupendous. The student will assist in studies of gene expression in bacteria exposed to antibiotics. Experience with PCR, gel electrophoresis and RNA isolation is desirable. Please submit a resume to Marcus Marvelous (marcusisthebest@fakemail.com). 

Some job announcements may be longer, some may even be shorter, but most share these main points: (1) what is the project, (2) what skills should you have, and (3) who to contact. In these three points lie the key to writing a strong cover letter.

Your simplest option is to open your e-mail, address a new message to Marcus Marvelous and write... 

Dear Marcus,
I am applying for the work study position in your lab. I have attached my resume.
Thank you,
Anna Aspiring 

Marcus Marvelous, a busy postdoctoral scientist in the Stupendous lab, receives this when he is waiting for an experiment to finish while eating his lunch at his desk and reading the latest, greatest research from some other lab. He thinks...<zzzzzzzzzzzzzz>.

Labs are looking for enthusiastic, self-motivated students who are eager about scientific research. Does anything in that e-mail sound enthusiastic or eager? Nope. Your e-mail should convince Marcus Marvelous that you are the perfect person for the job. Your e-mail is your cover letter, and it can make the difference between an impressive application and a boring one. In a short paragraph or two, you can do a lot to make your application stand out. Here are some tips…

Diarrhea, international politics and genome sequencing

At this time two years ago, European countries were in the grip of a severe outbreak of foodborne illness. From May to July 2011, over 4,000 people were sickened, and at least 50 people died. The culprit was a bacterium called Escherichia coli. You might find this name familiar. We have E. coli living inside us as part of our gut microbial community. These E. coli quietly exist in symbiosis with us, processing some of the food we eat and possibly protecting us from pathogens. However, some strains of E. coli are not so mild-mannered. 

The strain of E. coli responsible for the 2011 European outbreak was equipped with the genetic weaponry to cause not only gastrointestinal illness, which includes bloody diarrhea, but also a potentially fatal condition called hemolytic-uremic syndrome, which can lead to kidney failure. Investigations of this outbreak impacted international politics and deployed cutting-edge technologies, ultimately demonstrating just how much these little microbes can disrupt our carefully constructed human lives.

Electron micrograph of E. coli bacteria, magnified 10,000X.

Return from hiatus!

It's been about two years since my last post. Yikes!

I really enjoyed working on this blog, but my research life made it difficult to find time. After two years away, I'm going to attempt to resume the blog because... (1) it was a wonderful way for me to broaden my knowledge of microbiology (unfortunately that PhD didn't come with an automatic brain download of Bergey's Manual of Systematic Bacteriology. Or maybe fortunately) and (2) it is even more important now for scientists to engage with the public. It's our job to share the wonder of science with interested listeners/readers (and the not-so-interested).

I hope to have something new posted within a couple of weeks!