A Comparison of Staphylococcus aureus Isolates from Laboratories LS 203 and LS 224 at York College...
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A Comparison of A Comparison of Staphylococcus aureus Staphylococcus aureus Isolates from Isolates from Laboratories LS 203 and LS 224 at York College of Laboratories LS 203 and LS 224 at York College of Pennsylvania Pennsylvania Introduction Introduction Staphylococcus aureus causes a variety of human diseases ranging in severity from skin infections and food poisoning to more lethal diseases such as pneumonia and toxic-shock syndrome (Kuroda et al. 2001). S. aureus is one of the most pathogenic species of staphylococci and is a major cause of nosocomial infections. In addition, it is becoming increasingly associated with community-acquired diseases. Isolates of Staphylococcus aureus can be found most commonly in the nasal membranes, throat, and skin of some healthy individuals, which makes it easy to spread these illnesses in public places (Jacobs et al. 1961). b b h h g g f f e e d d LS 224 LS 203 Area Sampled LS 203 LS 224 DOORKNOB (back door) - - DOORKNOB (front door) + - GARBAGE CAN (front) + - CABINET HANDLE + + CHAIR 1 + + CHAIR 2 + - CHAIR 3 - - LIGHT SWITCH (front) - + BACK BENCH - - MIDDLE BENCH - - INCUBATOR - - BALANCE - - MICROWAVE - - EQUIPMENT COUNTER - - SUPPLY COUNTER - - Total 5 3 Objectives Objectives ► To survey the frequency of Staphylococcus aureus in biology labs LS 224 and LS 203. ► To compare the number of areas in each lab that tested positive for Staphylococcus aureus. ► To observe and compare specific objects/sites found to contain S. aureus in both laboratories. Figure 1. Gram stained slides that contained S. aureus. Red circles indicate clusters of Staphylococcus aureus. a) front light switch b) cabinet handle c) chair d) chair e) front doorknob f) chair g) cabinet handle h) front garbage can Figure 1 Table 1. Each object sampled and whether it tested positive or negative for Staphylococcus aureus. Collection of Samples • samples collected using sterile cotton swabs • swabs were placed in sterile tubes containing staph broth Incubated samples @ 37°C for 72 hours Streak Plate Method • all samples were plated on mannitol salt agar containing a phenol red indicator • one sample on each plate •Allowed bacteria to grow for 4 days Gram Stain •Yellow colonies from plates Slide Agglutination Test •All samples with yellow bacterial growth (test for coagulase) Methods Methods a a c c Conclusions Conclusions 1) No apparent difference in the amount of positive sites between the two labs. 2) No obvious difference between the specific objects containing S. aureus in each laboratory. Results Results • 5 out of 15 samples (33%) in LS 203 were positive for S. aureus (Table 1). • 3 out of 15 samples (20%) contained Staphylococcus aureus in LS 224 (Table 1). • 3 samples in LS 203 were positive for S. aureus while the same 3 sites in LS 224 were negative. • Only one sample in LS 224 was positive while the same object in LS 203 was negative. • There was an insufficient sample size to conduct a sign test (Ostle 1963). Literature Cited Literature Cited Jacobs, S., Williamson, G., and Willis, A. 1961. Nasal abnormality and the carrier rate of Staphyloccocus aureus. J. clinical Pathology 519-521. Kuroda, M., Ohta, T., Uchiyama, I., Baba, T., Yuzawa, H., Kobayashi, I., Cui, L., Oguchi, A., Aoki, K., Nagai, Y., Lian, J., Ito, T., Kanamori, M., Matsumaru, H., Maruyama, A., Murakami, H., Hosoyama, A., Mizutani- Ui, Y., Takahashi, N., Sawano, T., Inoue, R., Kaito, C., Sekimizu, K., Hirakawa, H., Kuhara, S., Goto, S., Yabuzaki, J., Kanehisa, M., Yamashita, A., Oshima, K., Furuya, K., Yoshino, C., Shiba, T., Hattori, M., Ogasawara, N., Hayashi, H., Hiramatsu, K. 2001. Whole genome sequencing of meticillin- resistant Staphylococcus aureus. The Lancet 357:1225-1238. Ostle, B. 1963. Statistics in Research: basic concepts and techniques for research workers . 2 nd Jacqueline Boyle Jacqueline Boyle Department of Biological Sciences, York College of Department of Biological Sciences, York College of Pennsylvania Pennsylvania Acknowledgements Acknowledgements Dr. Carolyn Mathur, Research Mentor Dr. Karl Kleiner Mrs. Barbara Taylor Dr. Bruce Smith Discussion Discussion Only four out of the fifteen paired samples revealed contrasting results. All other results were the same for both labs. Although LS 203 had a slightly higher number of samples that tested positive for Staphylococcus aureus, the difference between the two labs was not evident. A larger sample size would have been necessary in order to carry out the sign test and show whether there was a significant difference between the two laboratories. Abstract Abstract The majority of infections caused by Staphylococcus aureus are acquired in hospitals, but it is becoming more common to contract these illnesses through public places in the community. The purpose of this experiment was to test two laboratories and compare the areas that test positive for Staphylococcus aureus in each location. Standard methods such as gram staining were used as well as a slide agglutination test. Data revealed 33% of the samples tested positive for S. aureus in LS 203 and 20% in LS 224. No substantial difference in the prevalence S. aureus could be confirmed between the two labs.
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Transcript of A Comparison of Staphylococcus aureus Isolates from Laboratories LS 203 and LS 224 at York College...
A Comparison of A Comparison of Staphylococcus aureusStaphylococcus aureus Isolates from Isolates from Laboratories LS 203 and LS 224 at York College of Laboratories LS 203 and LS 224 at York College of
PennsylvaniaPennsylvania
IntroductionIntroduction
Staphylococcus aureus causes a variety of human diseases ranging in severity from skin infections and food poisoning to more lethal diseases such as pneumonia and toxic-shock syndrome (Kuroda et al. 2001). S. aureus is one of the most pathogenic species of staphylococci and is a major cause of nosocomial infections. In addition, it is becoming increasingly associated with community-acquired diseases. Isolates of Staphylococcus aureus can be found most commonly in the nasal membranes, throat, and skin of some healthy individuals, which makes it easy to spread these illnesses in public places (Jacobs et al. 1961).
bb
hh
ggff
eedd
LS 224 LS 203
Area Sampled LS 203 LS 224
DOORKNOB (back door) - -
DOORKNOB (front door) + -
GARBAGE CAN (front) + -
CABINET HANDLE + +
CHAIR1 + +
CHAIR2 + -
CHAIR3 - -
LIGHT SWITCH (front) - +
BACK BENCH - -
MIDDLE BENCH - -
INCUBATOR - -
BALANCE - -
MICROWAVE - -
EQUIPMENT COUNTER - -
SUPPLY COUNTER - -
Total 5 3
ObjectivesObjectives
► To survey the frequency of Staphylococcus aureus in biology labs LS 224 and LS 203.
► To compare the number of areas in each lab that tested positive for Staphylococcus aureus.
► To observe and compare specific objects/sites found to contain S. aureus in both laboratories.
Figure 1. Gram stained slides that contained S. aureus. Red circles indicate clusters of Staphylococcus aureus. a) front light switch b) cabinet handle c) chair d) chair e) front doorknob f) chair g) cabinet handle h) front garbage can
Figure 1
Table 1. Each object sampled and whether it tested positive or negative for Staphylococcus aureus.
Collection of Samples• samples collected using sterile cotton swabs• swabs were placed in sterile tubes containing staph broth
Incubated samples @ 37°C for 72 hours
Streak Plate Method• all samples were plated on mannitol salt agar containing a phenol red indicator• one sample on each plate•Allowed bacteria to grow for 4 days
Gram Stain•Yellow colonies from plates
Slide Agglutination Test•All samples with yellow bacterial growth (test for coagulase)
MethodsMethods
aa
cc
ConclusionsConclusions
1) No apparent difference in the amount of positive sites between the two labs.
2) No obvious difference between the specific objects containing S. aureus in each laboratory.
ResultsResults
• 5 out of 15 samples (33%) in LS 203 were positive for S. aureus (Table 1).
• 3 out of 15 samples (20%) contained Staphylococcus aureus in LS 224 (Table 1).
• 3 samples in LS 203 were positive for S. aureus while the same 3 sites in LS 224 were negative.
• Only one sample in LS 224 was positive while the same object in LS 203 was negative.
• There was an insufficient sample size to conduct a sign test (Ostle 1963).
Literature CitedLiterature Cited
Jacobs, S., Williamson, G., and Willis, A. 1961. Nasal abnormality and the carrier rate of Staphyloccocus aureus. J. clinical Pathology 519-521.
Kuroda, M., Ohta, T., Uchiyama, I., Baba, T., Yuzawa, H., Kobayashi, I., Cui, L., Oguchi, A., Aoki, K., Nagai, Y., Lian, J., Ito, T., Kanamori, M., Matsumaru, H., Maruyama, A., Murakami, H., Hosoyama, A., Mizutani- Ui, Y., Takahashi, N., Sawano, T., Inoue, R., Kaito, C., Sekimizu, K., Hirakawa, H., Kuhara, S., Goto, S., Yabuzaki, J., Kanehisa, M., Yamashita, A., Oshima, K., Furuya, K., Yoshino, C., Shiba, T., Hattori, M., Ogasawara, N., Hayashi, H., Hiramatsu, K. 2001. Whole genome sequencing of meticillin-resistant Staphylococcus aureus. The Lancet 357:1225-1238.
Ostle, B. 1963. Statistics in Research: basic concepts and techniques for research workers. 2nd ed. The Iowa State University Press, Ames, Iowa.
Jacqueline BoyleJacqueline Boyle
Department of Biological Sciences, York College of Department of Biological Sciences, York College of PennsylvaniaPennsylvania
AcknowledgementsAcknowledgements
Dr. Carolyn Mathur, Research MentorDr. Karl Kleiner
Mrs. Barbara TaylorDr. Bruce Smith
DiscussionDiscussion
Only four out of the fifteen paired samples revealed contrasting results. All other results were the same for both labs. Although LS 203 had a slightly higher number of samples that tested positive for Staphylococcus aureus, the difference between the two labs was not evident. A larger sample size would have been necessary in order to carry out the sign test and show whether there was a significant difference between the two laboratories.
AbstractAbstract
The majority of infections caused by Staphylococcus aureus are acquired in hospitals, but it is becoming more common to contract these illnesses through public places in the community. The purpose of this experiment was to test two laboratories and compare the areas that test positive for Staphylococcus aureus in each location. Standard methods such as gram staining were used as well as a slide agglutination test. Data revealed 33% of the samples tested positive for S. aureus in LS 203 and 20% in LS 224. No substantial difference in the prevalence S. aureus could be confirmed between the two labs.
