Is The Prevalence of Staphylococcus aureus Increasing Among York College Students? By: Angel Newson Department of Biological Sciences, York College of Pennsylvania Staphylococcus aureaus (S. aureus) is one of the leading causes of bacterial infections and is the most commonly identified multi-drug resistant pathogen in many parts of the world including the United States. Of the 94,000 persons infected in 2005, 19,000 died (Sampathkumar, 2007). S.aureus is a gram-positve bacterium frequently found in nasal passages of healthy individuals or carried on the skin. An average of 25% to 30% of the U.S. population is colonized in the nose for S. aureus. Asymptomatic colonization of S. aureus is more common than infections (Weber, 2008). Two places where MRSA has been identified are athletic clubs and hospitals. There are five factors that facilitate transmission of Community associated MRSA: Crowding, direct skin-to-skin contact, compromised skin such as cuts or abrasions, sharing of items or surfaces contaminated by wound drainage, and cleanliness and hygiene (Weber, 2007). MRSA has become resistant to a majority of the Beta- lactam antibiotics, which target bacterial enzymes that are critical to cell wall synthesis (McCarthy, 2003). MRSA strains carry a gene known as mecA that is responsible for its resistance. ***Objectives***  To determine the correlation between gender, healthcare workers, and athletes with the prevalence of coagulase-positive S. aureus on York College Campus  To compare the prevalence of coagulase-positive S. aureus at YCP between 2007 and 2008  To determine the antibiotic resistance of the samples by measuring B-lactamase activity  To compare coagulase-positive S. aureus detected from both nasal and skin samples Introduction Abstract Methods Results Figure 2. Comparison of Coagulase+ and B- lactamase+ nasal samples between male and females. The total amount of individuals positive in each category is represented by the blue bar. Number of Male or females are represented by the corresponding color coded bar. Figure 1. Comparison of Coagulase + and B-lactamase + S. aureus nasal samples between individuals associated with healthcare and athletics. Both male and female samples are included. Discussion Literature Cited McCarthy, Michael. Resistant Bacteria Spread Through US Communities. The Lancet 2003;362(9395): Sampathkumar, Priya. Methicillin-Resistant Staphylococcus aureus: The Latest Health Scare. Mayo Clinic Proceedings 2007; 82(12): Weber, Carol J. Update on Methicillin-Resistant Staphylococcus aureus (MRSA). Journal of Urologic Nursing 2008; 28(2): Acknowledgments: Carolyn Mathur, PhD, YCP Research Mentor Jeffery Thompson, PhD, YCP Senior Thesis Instructor Figure 3. Comparison of nasal and skin samples of coagulase positive S. aureus. Positive coagulase samples were tested for the presence of B-lactamase. None of the coagulase positive skin samples tested positive for B-lactamase. * indicates a significant difference in B-lactamase positive nasal and skin samples (p=0.0037). Collected 58 Nasal and 22 skin swabs from YCP students Growth in M-Staphylococcus Broth Mannitol Salt Agar Plate Streaks Coagulase Testing B-Lactamase testing Data was recorded at each experimental phase Statistical analysis was conducted using Fisher’s exact testing CharacteristicN¹ # Of positive (%) N¹ # Of Positive (%) All Students58 18 (31.0)10227 (26.5) Females4313 (30.2)7721 (27.3) Males155 (33.3)256 (24) Athletics3912 (30.8)5113 (25.5) Healthcare215 (23.8)205 (25) Athletics and Healthcare 145 (35.7)73 (42.9) N¹= sample size Table 1. Comparison of Staphylococcus aureus prevalence among nasal samples of York College Students between 2007 and Correlation between coagulase positive Sa nasal samples for 2007 and 2008 showed no significant difference (P=0.5852). An upward trend was observed between sample years. The percentages of positive nasal samples were 26.5% and 31% for 2007 and 2008 students, respectively. B-lactamase positive Sa skin and nasal samples were very significant (P= ). Percentages for positive nasal samples were 77.8% compared to 0% of skin samples. The percentage of coagulase positive Sa nasal samples (31%) showed no significant difference in comparison to the coagulase positive Sa skin sample percentage (23%), P= Percentage variations among characteristics were minimal. There was no difference in the percentage of Sa coagulase positive students who participated in athletics, healthcare affiliate, or a combination of the two characteristics. Positive results for both Coagulase positive Sa and B- lactamase positive Sa were higher among female samples. Figure 4. Represents the process by which the presences of B- lactamase enzymes break penicillin bonds. This reaction causes the deactivation of penicillin. The inactive form is unable to kill bacteria which ultimately increase the resistance of the microorganism. This mechanism is one of many ways in which bacteria become resistant to various antibiotic treatments. The study indicates that there was no significant difference in coagulase positive Sa prevalence between 2007 and The number of female samples that were coagulase positive increased approximately 10%. The total number of student samples for 2007 was 102. Of the 102 sampled, only 27 were coagulase positive (26.5%). In contrast to 2007 samples, 18 of the 58 students tested positive (36%) in 2008 samples. This increase, however, was not significant. There is no correlation between healthcare and athletic affiliation, and the prevalence of S. aureus among YCP students. Skin samples were similar when compared to nasal samples tested for coagulase positive Sa. None of the Sa skin samples tested positive for B-lactamase. Almost all of the nasal Sa samples that were coagulase positive also tested positive for B- lactamase (14 of 18 = 78%). Although there was no difference between the skin and nasal Sa coagulase tests, there was a difference in antibiotic resistance. S. aureus from samples of the nasal area was characteristically more resistant than skin samples. Although some students could potentially carry a resistant strain of S. aureus in nasal membranes, lack of its presence on student skins prevents spreading of the bacteria when students are in close contact. Conclusion S. aureus infections have been and will continue to rise in the immediate future. It is necessary to assess the impact that MRSA and other staph infections will have on local communities. It has breached the hospital barrier and is now potentially a threat for the entire population. Although this current study suggest a small, insignificant increase in the prevalence of S. aureus at York College, additional sampling of a larger, more diverse student population would be ideal in measuring its presence among YCP students. * Community associated Methicillin-Resistant Staphylococcus aureus (MRSA) infections have been increasing over the past several decades. S. aureus, once know as a hospital-acquired infection, is responsible for numerous hospitalizations annually. Infections are caused by community-acquired or hospital-acquired S. aureus. Nasal and skin samples from current York College students were collected and tested for the presence of coagulase positive S. aureus and B-lactamase enzymes. Statistical analysis were conducted to determine the relation between the prevalence of coagulase positive S. aureus samples and gender, healthcare affiliation, and athletic activity. When compared to a similar experiment conducted by a former student in 2007, there was no significant difference among coagulase positive S. aureus nasal samples between 2007 and 2008, although there was a slight increase. S. aureus B-lactamase positive nasal samples showed a significant difference when compared to skin samples. As the bacteria continues to spread throughout communities, the number of individuals carrying the bacteria or infected with the bacteria are expected to increase. # of students