All posts by kdshives

Rock Your Recruitment

2013/02/04 kdshives 3 Comments

It’s that time of year again!

Some of you reading this article are about to start your first round of graduate school interviews this spring. Many of these interviews will take place during what is known as recruitment weekend. However, this is a much different process than your standard job interview and you should be aware that there are some key differences between the two. While much of this advice comes from my own experience in the sciences and will vary according to your program, there are some basic themes to be aware of. Continue reading Rock Your Recruitment →

Hepatitis C, Techniques, Viral Disease

Tiny particles with big consequences: The number of viruses it takes to start an infection

2013/02/03 kdshives Leave a comment

Hepatitis virions, of an unknown strain of the... — Hepatitis virions (Photo credit: Microbe World)

My last post was written to introduce the concept of quasispecies in an RNA virus population.

This article will further expand on the topic and show how the quasispecies concept was used with powerful genetic sequencing technology to figure out a specific question: How many hepatitis C virus particles does it take to start an infection in humans? Continue reading Tiny particles with big consequences: The number of viruses it takes to start an infection →

Important Concepts

The Concept of Quasispecies

2013/01/11 kdshives 7 Comments

Today’s topic is directly related to my own research with RNA viruses and is what I consider a very interesting topic: quasispecies.

Many of us are familiar with the concept of a species at the macro (visible) scale. Dogs are dogs; pigs are pigs, and so on. Each is a distinct species based on the fact that they can only reproduce and generate fertile offspring with other members of the same species. Over the course of many generations mutations may arise in these populations which lead to different genotypes in the species. Left long enough, these two subpopulations may keep mutating to the point where they can no longer interbreed and become their own genetically distinct species. However, when you get down to the viral scale species becomes a much more difficult concept. Viruses don’t have sex in the traditional sense, so how can they be a species?

Continue reading The Concept of Quasispecies →

Bacterial Disease, Outbreak, Social Outreach, Vaccines, Viral Disease

Going against the herd: The importance of mass immunity in society

2012/12/27 kdshives Leave a comment

Why is it that members of the public health community are worried about falling vaccination rates in the US when getting vaccinated is treated as a largely personal choice? Do our personal health decisions for ourselves and our children have an impact on the health of society as a whole?

The answer to this is that yes, our individual decisions do matter to society when it comes to combating the spread of contagious disease.

A large part of this is herd or community immunity; the way in which mass immunity in a population can control the spread of disease among individuals. Herd immunity is a major reason behind why so many deadly diseases have all but disappeared from American society; our vaccination rates protect many of those who are unvaccinated from contagious diseases. However, this is beginning to change in the US and we are beginning to see outbreaks of diseases that have not been of major clinical concern for decades.

Read on to find out more on how herd immunity and how it protects vulnerable members of society. Continue reading Going against the herd: The importance of mass immunity in society →

Ask a Microbiologist, General

Ask a Microbiologist #3: What’s in the almond milk?

2012/12/10 kdshives 3 Comments

Today’s installment of Ask a Microbiologist comes from a reader wondering what might be in that old almond milk in the fridge:

“I found an open container of almond milk in my fridge the other day and it was OLD – I’m talking it had been opened for at least a month at this point. I know that as soon as it’s opened, the pasteurized almond milk is immediately primed for bacterial breeding. I was just curious as to which pathogenic (entero) bacteria are most likely to colonize at this point; I’m curious because there were zero indications of growth (ie no swelling of the container and no abnormal smells, colors, or textures).”

-Wondering what’s in there

Well WWIT, I’m glad you asked this, as I was starting to wonder about my soy milk as well.

This is a very open ended question and three main ways to inoculate your drink that could potentially lead to different contaminating microbes, some of which could be pathogenic. Continue reading Ask a Microbiologist #3: What’s in the almond milk? →

Fungal Disease, General, Mycology

Beyond Fever: Fungal infections and the benefits of body heat

2012/12/03 kdshives Leave a comment

So far on this site I’ve tried to address microbiology topics from all areas of the field; from the standards in bacteriology and virology to some more exotic parasites and fungal infections. When you look at the range of infections that people can acquire you see many bacteria, viruses, and parasites. However, invasive fungal infections, especially those that occur in healthy immune-competent hosts, are exceedingly rare when you compare mammals to insects, plans, and amphibians. I never gave this much thought until coming across a group of papers that together indicate that something as fundamental as a warm body temperature could protect us from a variety of pathogenic fungi.

Read on to see how endothermy may be a protective mechanism against fungal disease. Continue reading Beyond Fever: Fungal infections and the benefits of body heat →

K.D.Shives