Search Results for staph

Birth Control: an invitation for Staphylococcus aureus

English: This SEM shows a strain of Staphyloco...

This SEM shows a strain of Staphylococcus aureus bacteria taken from a vancomycin intermediate resistant culture (VISA). (Photo credit: Wikipedia)

Michele Taylor (11 AM Micro) found the following story about how a common medication can alter the carriage of relatively benign microorganisms in healthy individuals, potentially leading to a higher incidence of disease. Here is Michele’s summary:

An article found on livestrong.com states that in 2009, “according to the Center for Disease Control and Prevention, more than 80 percent of women in the United States have taken birth control pills at one time in their lives.”

The use of birth control pills has increased for those both sexually and non-sexually active. This is accredited to the benefits the pill comes with, which include: avoiding pregnancy, reducing menstrual cramps, causing lighter menstrual periods, and preventing uterine and ovarian cancer, ovarian cysts, and acne. In addition, there are many different types and strengths of this medication that can be taken. This is important in avoiding any unwanted side effects. These effects range from weight gain to nausea. They negative side effects are often overlooked with the benefit of the pills and the convenience of being able to switch prescriptions. However, a new side effect that has drawn the media’s attention is the risk of carrying staph bacteria.

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Staphylococcus in the nose

Via the review journal Trends in Microbiology, authors from the University of Tubingen (Germany) have reviewed the major determinants that allow Staphylococcus aureus  to colonize the human body. Previous epidemiological studies have examined the source of nosocomial infections by S. aureus, and have found that many of these infections occur by endogenous means, or from the patient’s own microbial flora as opposed to being introduced from other sources. Understanding the relationship between the host and the microbe then becomes essential for identifying means for controlling hospital acquired infections.

Previous genetic analysis of individuals with persistent (greater than several months) colonization by S. aureus has identified several possible, but no conclusive host traits that might explain why these individuals remain infected for so long. The role of a number of S. aureus  surface determinants have also been identified from genomic studies, including a number of factors that aid in the attachment of the bacterium to nasal epithelial cells. Shedding of bacteria occurs constantly via the continual loss of epithelial cells and the action of mucous membranes, and consequently the bacterial reproductive rate in this environment is high. The bacterium also makes a number of potent immune system evasion factors, such as staphylokinase which in addition to promoting dissemination, also allows complement and bound IgG to be deactivated.

Individuals with long term colonization do appear to receive some benefit from the arrangement, should they avoid an unfortunate complication during hospital care. Competition by long term microbial residents such as S. aureus can prevent the colonization by other more virulent organisms via the process of microbial antagonism. One well documented study examined the protective effects of sensitive S. aureus in preventing acquisition of methicillin-resistant isolates. Additionally, individuals with these organisms also appear to make more antibodies against several important S. aureus virulence traits such as toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxin.

The upshot of the review is that there exists a complicated interaction between the host and the microorganism, and a variety of determinants are critical for determining the effectiveness of the interaction. Genetic analysis of S. aureus isolates of human origin indicates that although there is heterogeneity in bacterial factors, by in large most isolates are relatively similar and equally able to colonize the human nose.  Factors that are much more significant likely exist on the host side and are currently under study. However, the utility of unraveling the complexity of host factors in light of the generally more simplistic diversity of pathogen factors seems to be less important than devising mechanisms to block S. aureus determinants in the first place.

Want to kill Staph? Turn on the lights

So here’s something new: as summarized in this Science Daily article, scientists at the University of New Mexico are looking at a novel strategy for the elimination of bacteria from surfaces. The need is great for us in the United States. As noted by Science Daily:

… increased infection and resistance rate has not been met with a simultaneous development of novel antimicrobial and antibiotic agents; in fact, only three classes of antibiotics have been developed since the 1950s…

The researchers at UNM are utilizing a novel set of compounds (“conjugated polyelectrolytes” or CPEs) that have marked bacteriocidal activity towards Gram negative bacteria. Newly developed light-activated CPEs are essentially inert to living cells when they are in the dark, but are bacteriocidal when exposed to light. There are many potential applications from this technology, one of which as discussed by the editor of Science Daily could be to ultimately incorporate these materials into a new type of antibacterial countertop that can be sterilized by turning on the lights.  Read the rest of this entry

Some Holiday spirit for the class

In searching through the Internet this morning, I found some microbiology art to help us get into the season!

Staphylococcus and Serratia; Author(s):Tasha Sturm, Cabrillo College

Staphylococcus and Serratia; Author(s):Tasha Sturm, Cabrillo College

Another Christmas tree!

fungal-christmas; via Stephanie Mounaud, JCVI

Star: Talaromyces stipitatus; Tree: Aspergillus nidulans Ornaments: Penicillium marneffei; Trunk: Aspergillus terreus – via Stephanie Mounaud, JCVI

Some yummy cookies!

Not OK to eat in lab, via Ms. Humble

Not OK to eat in lab, via Ms. Humble

Uh, Ebola and MRSA!

Lots of yuckier examples if you click the picture, via Wendy Staples

Lots of yuckier examples if you click the picture, via Wendy Staples

Rethink your Decision to Play Contact Sports

staph2Ashley Hiltebeitel (12:00 Micro) found another summary of microbes in the news from Science Daily. This one details the occurrence of MRSA in student athletes. This should come as no surprise to BIO230 students, who have been the subjects of scientific experiments looking at Staphylococcus aureus on YCP students in the past–click through to see how much Staphylococcus is in Nurses who have already gone through this class. Here is Ashley’s summary:

Even without showing signs and symptoms of of an infection, IDWeek2014 is presenting a study that Staphyloccocus aureus, more commonly known as MRSA, can be carried within college athletes who play contact sports such as football and soccer. This study shows that carrying the infection without showing symptoms puts them at a higher risk to obtain infection or spreading it to their peers or teammates. This disease can cause a serious infection which could lead to death. IDWeek2014 is the first to study athletes in college who are not part of a larger MRSA outbreak.

While carrying this microorganism in their noses and throats, contact athletes are twice as likely to be colonized with MRSA than people who do not play contact sports such as tennis and golf. To show the extreme difference, the two year long study performed by IDWeek2014 showed an 8 to 31 percent range of colonization of MRSA in those who play football, soccer, or other contact sports compared to 0 to 23 percent of those athletes who do not contact their opponent.

staphNatalia Jimenez-Truque, PhD, MSCI, research instructor, Vanderbilt University Medical Center, Nashville, Tenn. states that even without the full scale of the outbreak, a substantial number of athletes are being colonized with the harmful bacteria. She is convinced that the spread of the disease can be decreased within sports teams by reminding athletes to have good hygiene which includes more hand washing and not sharing personal items in the locker rooms such as towels, soaps, and razors.

The study being presented by IDWeek2014 researched the time it takes for Staphylococcus aureus to be colonized within an athlete. 377 male and female Vanderbilt University varsity athletes were observed. This group included 14 different sports. The contact sports observed were football, soccer, basketball, and lacrosse, while the non-contact sports included baseball, cross country, and golf. The number of participants for the contact sports were 224 and the the number for the non-contact sports were 153. Monthly nasal and throat swabs occurred over two academic years for each athlete. MRSA was found to be acquired more quickly and longer in contact athletes over non-contact athletes.

Skin and soft tissue infections are the result of MRSA. The infections usually heal on their own or can be easily treated. Pneumonia and infections of the blood, heart, bone, joints, and central nervous system can come from the invasive form of MRSA and kill about 18,000 people every year. This is harder to treat than the skin and soft tissue infections because doctors use powerful antibiotics delivered through an I.V.

When an athlete who plays a contact sport has cuts and scrapes on their body, they have a higher risk of getting colonized or infected with MRSA. Researchers suggest that this can be avoided by covering open wounds, regularly washings hands, showering after all practice and games, and not sharing personal items as mentioned before. They also suggest that athletes with scratches and cut should not be allowed to practice or play in games. MRSA is often spread person to person because researchers found little staph in a clean athletic environment.

In conclusion, Jimenez-Truque states that, “Staph is a problematic germ for us — always has been, always will be — and we need to do all we can to reduce the risk of infection in those at highest risk, such as college athletes.”

Streptococcus pneumonia: Are you at Risk?

Red blood cells on an agar plate are used to d...

Red blood cells on an agar plate are used to diagnose infection. The plate on the left shows a positive staphylococcus infection. The plate on the right shows a positive streptococcus infection and with the halo effect shows specifically a beta-hemolytic group A. (Photo credit: Wikipedia)

Olivia Rehman (11 AM Micro) found some articles discussing the complex relationship between members of the normal microbiota, and influenza. Here is Olivia’s summary:

While looking at Science Daily, I was interested to find two similar articles that discussed the bacteria Streptococcus pneumonia. While this is typically a harmless bacterium found in the linings of throats and noses of most people, it can quickly cause disease under certain conditions. For years, scientists have been researching the “cause” of this change from harmless to pathogenic.

In April of 2011, scientists had claimed that these bacteria are only able to spread when individuals are infected with the flu. This article titled, “Flu Helps Spread Pneumonia,” goes on to support this theory using infant mice. He found that all mice had to be infected with the flu for the bacteria to spread and that by blocking the flu infection; the mice did not spread the disease.  They explained this phenomenon by stating that flu virus increases the bacterial load in the nose and for others it alters host immunity, making individuals more susceptible. While this study in 2011 may have identified a cause of this disease, a more recent article takes a closer look.

In August of 2013, researchers from the University of Buffalo studied how Streptococcus pneumonia spreads and becomes a virulent pathogen. In this article from Science Daily, the team was looking to find ways to interfere with the disease transmission to possibly block the process and prevent disease from happening. They found that S. pneumonia form biofilms within the nose and cause disease when the bacteria travel to the lungs or the middle ear. By growing biofilms on top of human epithelial cells, they infected the bacteria with influenza A virus, or exposed them to other similar conditions that accompany the flu such as increased temperature, higher amounts of ATP, and the hormone norepinephrine. These stimuli produced a sudden release of the bacteria from the biofilm in the nose into other areas such as the middle ears, lungs or bloodstream. They also noticed that the gene expression of the bacteria revealed more virulence. This causes some sort of “interkingdom” signaling and the bacteria respond to the host molecules. Researchers hope that by finding ways to interrupt the signaling they can prevent this disease from happening altogether.

Currently 80% of children carry the bacteria in their nose and if infected with influenza, are susceptible to life-threatening secondary infections like meningitis, pneumonia and sepsis. Statistics show that more than one million children under the age of five die from S. pneumonia each year. This is just one of the many examples of how opportunistic infections occur and hopefully we will be able to intervene and prevent these deaths in the near future. By looking at articles two years apart, it seems that science is making some advances in their research. While they haven’t found the answer to prevention just yet, they are gaining more knowledge about the organism and gathering a better understanding of how it works. It seems that our best prevention now is to get vaccinated for the flu.

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