Aureus Current Areas of Research

Much of the current research on staphylococcus aureus centers on the emergence of antibiotic-resistance strains. In particular, the resistant strain MRSA is resistant to methicillin and related drugs. This has created a number of issues for medical practitioners, as staph infections are one of the more common infections that occur in a health setting.

One of the threads of research in this regard concerns the spread of staph infection in the hospital setting. It has long been believed that s. aureus infections were transmitted between patients. Where outbreaks have occurred, the response has generally reflected this view, with patients being segregated, and other similar remedies. Recent research has shown, however, that transmission between patients in the intrahospital setting does not occur nearly as much as previously thought (Long, Beres, Olsen & Musser, 2014). This is an important finding for health care facilities, because it changes the way that staph outbreaks are conceived, and thus the way that are dealt with in the hospital setting.

There are a number of different strains of staphylococcus that can exist in a hospital setting, staph being heterogeneous. S. aureus is fairly well-established in many hospitals. The risk of staph infection is therefore fairly high. The authors tested the genomes of S. aureus that they found in four Houston-area hospitals over a period of six months, and their findings indicated that these were not the same staphylococcus passed from one patient to another, but were independent. Thus, where a staph infection occurs, it may have more to do with overall cleanliness of the facility, because patients are not transmitted the staphylococcus to each other, but contracting it independently. The findings lead the authors to conclude that there is a fundamental difference between everyday staph infections and outbreak scenarios. The findings in particular indicate that much testing on which current knowledge is based is not refined enough to detect subtle differences between staph strains -- being able to identify different strains enabled the authors to determine that infections were not usually transmitted between patients, but instead tend to be independently acquired. This has significant consequences for how hospitals deal with infection, and it also sheds some new light as to the nature of staphylococcus the hospital setting.

Another thread of research is with respect to chronic staph infections. Kriegeskorte et al. (2014) investigate this at the genetic level. They studied thymidine-dependent small-colony variants of staphylococcus aureus and found that these variants contained mutations in ThyA. These mutations were leading to inactivity of thymidylate synthase proteins. This inactivity in turn led to increased S. aureus virulence and genes responsible for colonized were upregulated. The result of this is that these particular strains colonize more easily, with increased virulence. This mechanism is what is responsible for the chronic staph infections that were studied.

The findings are important because these virulent small-colony variants are common in patients who are receiving long-term treatment with trimethoprim-sulfamethoxazole (TMP-SMX),an antibiotic that is widely used to treat a number of different infections. The findings also suggest, though do not prove, that the mutations have occurred because of heavy use of this antibiotic. The strain has adapted so that the long-term use of the antibiotic results in the mutation to the more virulent strain, and that is the cause of the chronic S. aureus infection in the patient. There are implications for treating such chronic infections, but also for determining the best course of action for dealing with the underlying infection in a manner that does not encourage the development of the mutations in the staphylococcus in the first place.

A third thread of current research is with respect to finding ways to treat the methicillin-resistant strains of staphylococcus aureus. These strains are particularly challenging for those in the hospital environment, because they are not only common but are resistant to common antibiotics. The authors studied emulsifying agents for essential oil formulations. They looked at rhamnolipids can be made from waste frying oil, and using them as the emulsifying agent can create essential oils that are used to treat S. aureus and another challenging infection, Candida albicans. The essential oils that were used in their study were melaleuca alternifora, cinnamonium verum (cinnamon), origanum compacum (a member of the oregano family), and lavandula angustifloria (lavender).

The findings are that this method of emulsifying the essential oils increase the antimicrobial effect, which should aid in the treatment of these...

The authors also note that the use of edible oil waste in the production of rhamnolipids lowers its cost, because this oil waste is so readily available. However, the authors noted that in some cases, antimicrobials did not interact with the microbial cells, where in other cases they did. The authors did not seem to have an explanation to help predict the differences, but noted that when there was no direct interaction with microbial cells, the antimicrobials were, not surprisingly, ineffective.
Overall, each of these areas of research highlights the fight against staphylococcus. Researchers are learning more about how this infection spreads, and how better to handle the resistant strains. One approach is to understand on a genetic level how the microbe works, and another seeks to refine the techniques for fighting it. So all of these different area of research contribute to the fight against staph infections, in particular the fight against the strains that are resistant to antibiotics. The genetic approach in particular reflects the application of new technology in the fight against these strains, by allowing researchers to understand these strains better than they have in the past.

2. Microbes are still a major health concern. The issue with S. aureus in particular is that there are many different strains, and some of these have become resistant to antibiotics. In particular, researchers are learning that patients with long-term antibiotic use are especially susceptible to infection from resistant strains. By understanding how this resistance comes about -- mutations in key genes, allowing the microbe to actually become more virulent in patients on long-term antibiotics, the microbe has remained a threat. Its ability to adapt to a challenging environment makes it a persistent threat. Furthermore, what researchers are learning about how these microbes spread is enlightening. The prior approaches to dealing with staph infections has been predicated on assumptions that are no disproven. The microbes have remained relevant.

There is still some information that is lacking. The articles do not talk as much about what is lacking --that's a lot more open-ended -- but researchers are trying to learn more about the behavior of these microbes. They are trying to learn more on the genetic level about them, so that they can determine what genetic-level approaches can be used to help fight these microbes. Ultimately, that is the knowledge that is being sought here, how to deal with staphylococcus infections in the hospital setting. It is a bit of a moving target, and new technologies allow for different research approaches, which is why there is a lot of research on the subject, approaching it from different angles. Ultimately, as long as staph infections are still common, there will be research into their mechanisms and the potential remedies that exist.

The biggest issue why staphylococcus cannot be overcome is that its genes are mutating. Traditionally, it could be treated with antibiotics, but at this point there are strains that are resistant to methicillin and this has allow for this form of infection to become increasingly prevalent, and more difficult to deal with. So the challenge arises from the overuse of antibiotics and the subsequent mutation of the genes to work around the antibiotics. The newer strains of S. aureus are more dangerous, and they are much harder to treat, because they have evolved to get around our traditional treatment methods.

In terms of unanswered questions, one issue that was identified is that the emulsions, while sometimes successful, were not always successful at inhibiting microbial activity. There are definitely some question about the methods that are used to handle these microbes -- if there were no unanswered questions then they would not have to research to find out how to stop these microbes.

Another unanswered question is about the genetic mechanisms. One of the important issues is to learn how the genes mutate. Regular staphylococcus is not as threatening as the methicillin-resistant strains, so the question is how does it evolve into one of those strains, and can that evolution be de-activated. There has been some progress on this, as the article indicates, but ultimately there remains a gap in our knowledge with respect to how to deal with this microbe on the genetic level. Some of the mechanisms that cause the evolution of antibiotic-resistant strains remain unknown, but if they are known then they can be reversed as well, at the genetic level. There is potential for a breakthrough in this regard, but key details remain unknown.

Overall, this is an important are for research, something that is reflected in the number of different approaches that researchers are taking to understand the issue and develop different…