Cutting Edge Research RIGHT Here at Sam!

                First of all, I’ll apologize since this is my third blog post of the week, but I COULD NOT not blog about this. You all should go to this article on npr and read the story. It’s about the research being done by our very own Dr. Bucheli and Dr. Lynne along with a team of scientists from Colorado and Baylor College of Medicine. This particular story was written/recorded in April before I joined the project, but I can tell you all that it’s an amazing project to be a part of.

                These scientists are working to find out whether the microbiome of decomposition can be used to estimate time of death of an individual. This work has been done with mice in a lab setting, but not with human cadavers. With this sort of information we may be able to one day pinpoint exactly how long a body has been somewhere, if a body was once in a specific location, or where a suspect was (and who they are) simply based on the bacteria which live on our body.

                I’m hoping that once I’m in the Biological Sciences Graduate Program here (crossing my fingers!), my thesis will hopefully revolve around some aspect of this research. My particular interest is in the changes found in soil microbiology, but every part of this research is fascinating to me! Maybe some of you will find it just as interesting as I do.  

Bog Goes the Cranberry Pest

I’ve recently developed somewhat of an addiction to cranberry juice. I’m not really sure how it happened, but one day I picked up the stuff and haven’t seemed to been able to put it down since. (So much for “somewhat” of an addiction…) While looking around Science Daily (we all seem to love this site don’t we?), I came across an article about insect resistance found in cranberry leaves. With the issues society is having with pesticides these days, I thought, Hmm…

                Since everyone tends to gravitate towards the “organic” produce and juices and blah blah blah now, I thought this was an interesting study. If was found that certain cultivars of cranberries were preferred over others by insects and this is likely due to six compounds which are found naturally in cranberry leaves which ward off the insects. Cranberries are a perennial crop, meaning they are harvested grow for more than two years and can produce many seasons of fruits. This means that an above average insect feeding activity can greatly affect the next season’s crop of fruit. Which is super bad for my juice addiction, right?

                These compounds that are found vary between cranberry cultivars, explaining why insect pests prefer one over another. If this information was found, I’m wondering if the cranberry crops cultivated for harvest may start to gravitate towards these cultivars in order to deter insect pests from destroying crops. I wonder if this type of information may be applicable to future studies to find natural pesticides to possibly breed into our crop cultivars to better suit the “organic” needs of consumers. Even though we all know “organic” isn’t all that organic.. 

The Staph says "Oink"

                Most of us all know that MRSA is an antibiotic-resistant Staph. infection. Specifically, MRSA is Methicillin-resistant Staphylococcus aureus, but the bacteria are resistant to most methicillin related antibiotics (like penicillin) as well. Researchers have now linked the community-acquired infection with yet another source: pig manure.

                First of all, MRSA has a couple of known sources as it is. Not only is MRSA acquired from extended hospital stays and surgery mixed with poor hygiene, but MRSA has also had a second rising in school-age and daycare attending children. The use of antibiotics for any-and-every-thing that pediatric doctors see has led to this rising of the antibiotic resistant staph. Recent studies have shown that MRSA may also rise from high production pig farms. Crop fields near these farms use the manure from the pigs to fertilize the crops. This has led to an increase in the MRSA infections within the surrounding communities. Scientists attribute this to the high antibiotic intake of the pigs. Because these pigs are used for their meat, the feed that they eat contains a high level of antibiotics, which is then shed when the pigs do their business.

                Studies which were performed based on skin and soft tissue infections, likely from contact with the crops or contact with the soil from these crop fields, showed that there was a significant association of MRSA and the application of the manure to nearby crop fields. Another association between MRSA and the operations that took place on the pig farms was found but it was weaker in association. Lastly, there was no association found between nearby dairy farm operations or applications and the MRSA infections. Moral of the story: if you want to live near a farm, (A) make sure they don’t use pig manure as their fertilizer if they have crop fields and (B) choose to live nears cows instead of pigs. 

Ladies, Know Your Lipstick!

                We've all seen detectives on crime shows pick up a champagne glass to examine the lipstick prints. We've also seen how that exact print, color, and brand was matched perfectly to either a victim or a suspect and within the hour the crime is solved. We all know how bogus that really all is. First of all, there is no way the crime was solved in an hour. Secondly, can they really match someone’s lipstick of all things? Isolating the DNA from any saliva mixed in the print, sure, but the brand? Maybe.

                Scientists from the University of Kent are now able to identify the brand of lipstick from crime scene lip prints. Not only can they do this, but they don’t even have to take the champagne glass (or water bottle, soda can, etc for all the non-fancy murderers) out of the evidence bag! Okay, okay, so crime scene techs have likely lifted the lip print in the past contrary to what TV shows depict, but now Raman spectroscopy is used to analyze the lipstick marks on a variety of pieces of evidence. Tissues, glasses, and even cigarette butts can be run under a specific type of laser light for analysis. This keeps evidence intact, allowing for it to be further processed if necessary.

                Prior to this advancement, scientists were forced to destroy evidence to analyze lipstick evidence. If that were not the preferred choice, the analysis had to be left to matter of opinions. I don’t know about you ladies, but sometimes Peachy-Pink Kiss can look a lot like Sunburst Coral to me. I wouldn't want someone to practically guess that the lipsticks match. Now that scientists have found that this technology can match brands of lipsticks, they’re working to apply this to other cosmetics as well.

If you’re interested in learning more about the Raman spectroscopy, you can read about the article I found here. 

Once Bitten, Twice Shy

                  I don’t know about the rest of you, but I HATE mosquitoes. I absolutely cannot stand them.  The feeling, however, is not mutual. I can go outside for a split second in the summer time and the next thing I know, I’ve been bitten a million times. It’s been this way for forever, and it seems as though nothing works. The spray is gross, smelly, and sticky (although they have a nice unscented “dry” one that came out recently that is definitely a step up!). Even if it does work, it’s only for a short time and then it wears off. Did anyone else ever try those ridiculous coil ankle bracelet things that were made by OFF which supposedly repelled mosquitoes without the need for the spray? Well if you didn’t, I can assure you, they didn’t work. Like I said, NOTHING seems to work. Until now?

          I found this article in Science Daily while trying to find something interesting (despite really just wanting to discuss more soil microbiology with applications to forensics). It discusses the efforts that are in progress to try to uncover a “new” and natural (?!) repellant that –get this– is produced by our skin! Because human skin releases a variety of compounds, the human “scent” is actually what attracts mosquitoes. Through a number of tests, scientists have isolated these compounds in order to try and determine which compounds specifically are the attractants. They found that certain substances clearly attract the insects, but others actually inhibit their sense of smell.

Um, yes, please! Can we get this by the gallon, anyone? Of course, this is all still in its preliminary stages of research, but it was found that these types of compounds are actually found in abundance in certain lotions, perfumes, and cosmetics. This would explain why some people don’t get bit as often… The main flaw with this article is that it fails to name some of these lotions and perfumes. I mean, geez, I am apparently not using the right ones, and would like to find out which are the right ones, pronto! 

Understanding Soil Microbiology

The study of soil microbiology as it relates to forensic science is a relatively novel idea. While DNA, dental records, and trace evidence has been used to determine identities of both suspects and victims, along with location of crime scene and other details, soil could potentially be used to determine if a victim was placed in a location then removed. By studying the microbial composition of soils around a decomposing body, scientists will be able to track the fluctuations and changes of microbes from the soil. Using this data, it could be determined how old a dump site location is, or if someone reported a dump site, this data could support or disprove such claims.

First, it is important that scientists understand the basics of normal soil microbiology. Soil microbiology was once studied by sampling soil sites and simply counting microbes from the samples [1]. This was not sufficient enough to develop a better understanding of the microbial composition of the soil.  Since these methods were not efficient enough, soil enzymes were studied. Because the presence of enzymes in the soil is indicative of the presence of microbes, it is important to study the enzymes that are found. By studying these enzymes, and through the knowledge of microbiology, scientists are able to link the enzymes with certain bacteria that undergo various enzymatic activities in order to survive in the soil [1].

Enzyme testing is not without its faults, however. Simply using the enzymes found in the soil and a background of microbiology will not show, for certain, which microbes can be classified as being present in the soil [1]. Instead of using enzymatic testing as confirmatory and characterizing tests, scientists will use the data gathered from these methods to monitor various details of the soil. Various approaches to testing soil have been proposed over the years in efforts to more clearly classify the microbiota of soil. Through enzymatic testing and metabolic analysis, the compositions of soils are better understood than they were fifty years ago, but the complete classification is still out of grasp.

Even more recently developed, DNA sequencing of soil samples has proven to be a relatively well informative method for determining what, and just how many, microbes compose the soil. While there are several methods which are currently used to study the DNA or RNA of soil microbiology, several in the science community have supported the ideas that molecular ecology is essential for the study of soil microbiology [1]. The future of understanding the microbiology of soil is still geared towards the continued study of microbial composition and activities through the use of molecular techniques [1]. Due to the vast contrast between the many soil types, along with the added complexities from climate, altitude, and geographic location, the complete composition of soil microbiota may never be absolutely determined. Along with all these complicating factors, the changes that are constantly taking place in these factors will continue to keep the soil microbiology from being completely determined.

By knowing the basics of soil microbiology, scientists should one day be able to more widely apply what is known in order to utilize soil from forensic cases to determine a variety of evidentiary information. Through the knowledge of general soil characteristics, scientists can already begin to study forensic applications for this information in efforts to utilize another route of evidence to help solve crimes. Because we already see widespread changes in crime scenes from the more well known aspects of crime investigation due to television, perhaps developing new techniques to uncovering clues will prove to be beneficial not only to the scientific community, but the criminal justice community as well.

Resources:

1. Insam, H. (2001). Developments in soil microbiology since the mid 1960s. Geoderma, 100, 389-402.