Transcript Emerging Pathogens - Promega Corporation

Emerging Pathogens
Community-Associated MethicillinResistant Staphylococcus aureus
©2008, Promega Corporation. All rights reserved.
Staphylococcus aureus
• Commonly colonizes the skin,
axillae, perineum, nasal
passages of mammals
• ~30% of the population is
temporarily or permanently
colonized
• Can be an opportunistic
pathogen
• Quickly develops resistance to
b-lactam antibiotics such as
penicillin and macrolide
antibiotics such as
erythromycin.
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Photo credit: Image #7488 CDC/
Rodney M. Donlan, Ph.D.; Janice Carr
Photo courtesy of the CDC Public
Health Image Library (PHIL).
HA-MRSA: Health Care-Associated MRSA
• Methicillin-Resistant Staphylococcus aureus (MRSA)
• Appeared in the 1960s
• First case reported in the UK in 1961 as a nosocomial
(hospital acquired) infection
• Reports from Japan, rest of Europe and Australia
• First case in the US in 1968
• Associated with hospitalization, long-term care, surgeries,
dialysis, ventilation, other invasive procedures
• multidrug resistant
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CA-MRSA: Community-Associated MRSA
• First cases in early 80s
• 1997-1999 four pediatric
deaths in Minnesota and
North Dakota were attributed
to CA-MRSA
• 2007, a high school athlete
died of CA-MRSA infection in
Virginia, two other HS
students ill
• 2007, 13 cases in Rockville,
MD high school and cases in
OH and MI
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Photo credit: Image #7821 CDC/ Janice
Haney Carr/ Jeff Hageman, M.H.S.
Photo courtesy of the CDC Public Health
Image Library (PHIL).
CA-MRSA
• Cases not associated with risk factors of hospitalization, long-term health
care, or invasive medical procedures
• Not as drug resistant as HA-MRSA
• Often carry gene encoding a skin cytotoxin allowing it to be invasive
• Populations at risk: people living in close quarters like dormitories,
military barracks, prisons; people participating in contact sports; injection
drug users
• Not a new bacterial species: common sense measures and good hygiene
are best practices to prevent spread and serious infection
• A video and other course materials on prevention of MRSA infection in
athletic settings are available from the CDC.
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References
• CDC Four Pediatric Deaths from Community-Acquired Methicillin
Resistant Staphylococcus aureus in Minnesota and North Dakota, 19971999. MMWR Weekly (1999) 48, 707-10.
• Naimi, T. et al. (2003) Comparison of Community- and Health CareAssociated Methicillin-Resistant Staphylococcus aureus Infection. J.
Amer. Med. Assoc. 290, 2976–84.
• Athletes Susceptible to Antibiotic-resistant Staph Infections. Science
Daily. http://www.sciencedaily.com/releases/2008/06/080624151110.htm
• Borlaug, G., Davis, J.P., Fox, B.C. (2005) Community Associated
Methicillin Resistant Staphylococcus aureus (CA MRSA): Guidelines for
Clinical Management and Control of Transmission. Wisconsin Division of
Public Health
• Klevens, R.M. et al. (2007) Invasive Methicillin-Resistant Staphylococcus
aureus Infections in the United States. J. Amer. Med. Assoc. 208, 1763–
71.
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