CC398 explained

CC398 or MRSA CC398 is a new variant of MRSA that has emerged in animals and is found in intensively reared production animals (primarily pigs, but also cattle and poultry), where it can be transmitted to humans as LA-MRSA (livestock-associated MRSA). A 2009 study shows, however, that dissemination of CC398 from exposed humans to other, non-exposed humans is infrequent.^[1] Though dangerous to humans, CC398 is often asymptomatic in food-producing animals.^[2] In a single study conducted in Denmark, MRSA was shown to originate in livestock and spread to humans,^[3] though the MRSA strain may have originated in humans and was transmitted to livestock.^[4]

A 2011 study reported 47% of the meat and poultry sold in surveyed U.S. grocery stores was contaminated with S. aureus, and of those 5–24.4% of the total were resistant to at least three classes of antibiotics. "Now we need to determine what this means in terms of risk to the consumer," said Dr. Keim, a co-author of the paper.^[5] Some samples of commercially sold meat products in Japan were also found to harbor MRSA strains.^[6]

An investigation of 100 pig-meat samples purchased from major UK retailers conducted by the Guardian in 2015 showed that some 10% of the samples were contaminated.^[7]

In 2017 17 out of 401 examined horses in Denmark were found to carry MRSA, typically strains of CC398.^[8] The same year it was reported that from 20142016 44 persons in Denmark were infected with LA-MRSA from fur farming mink and that LA-MRSA was found in 88% of Danish pig herds.^[9]

See also

• Carbapenem resistant enterobacteriaceae
• Necrotizing fasciitis
• Staphylococcus aureus
• Toxic shock syndrome
• XF-73
• Teixobactin

Notes and References

1. 10.1371/journal.pone.0006800. 19710922. 2728842. Nasal Colonization of Humans with Methicillin-Resistant Staphylococcus aureus (MRSA) CC398 with and without Exposure to Pigs. PLOS ONE. 4. 8. e6800. 2009. Cuny. Christiane. Nathaus. Rolf. Layer. Franziska. Strommenger. Birgit. Altmann. Doris. Witte. Wolfgang. 2009PLoSO...4.6800C. free.
2. Web site: Joint scientific report of ECDC, EFSA and EMEA on meticillin resistant Staphylococcus aureus (MRSA) in livestock, companion animals and food. | EFSA. www.efsa.europa.eu. 16 June 2009 .
3. 10.1002/emmm.201202413 . Whole genome sequencing identifies zoonotic transmission of MRSA isolates with the novel mecA homologue mecC . 2013 . Harrison . Ewan M. . Paterson . Gavin K. . Holden . Matthew T.G. . Larsen . Jesper . Stegger . Marc . Larsen . Anders Rhod . Petersen . Andreas . Skov . Robert L. . Christensen . Judit Marta . Bak Zeuthen . Anne . Heltberg . Ole . Harris . Simon R. . Zadoks . Ruth N. . Parkhill . Julian . Peacock . Sharon J. . Holmes . Mark A. . EMBO Molecular Medicine . 5 . 4 . 509–15 . 23526809 . 3628104 . 8.
4. Tomasz . Alexander . The use of whole genome sequencing to solve an epidemiological puzzle . EMBO Molecular Medicine . April 2013 . 5 . 4 . 486–487 . 10.1002/emmm.201302622. 23554168 . 3628098 .
5. Web site: US meat and poultry is widely contaminated with drug-resistant Staph bacteria, study finds . ScienceDaily.
6. Ogata K, Narimatsu H, Suzuki M, Higuchi W, Yamamoto T, Taniguchi H . Commercially distributed meat as a potential vehicle for community-acquired methicillin-resistant Staphylococcus aureus . Applied and Environmental Microbiology . 78 . 8 . 2797–802 . 3 February 2012 . 22307310 . 3318828 . 10.1128/AEM.07470-11. 2012ApEnM..78.2797O .
7. News: Harvey . Fiona . Wasley . Andrew . Stuart . Caz . Carson . Mary . O'Kane . Maggie . Mann . Ben . Baqué . Irene . Lukic . Dee . Parkar . Yusuf . 18 June 2015 . The pig superbug and the baby – video . The Guardian .
8. News: MRSA-bakterier er fundet i 17 danske heste . . Christian Bæk . Lindtoft . 18 April 2017 . 18 April 2017 . da . MRSA bacteria found in 17 Danish horses.
9. News: 44 personer smittet med husdyr-MRSA fra mink på tre år . . Politiken . 2 March 2017 . 18 April 2017 . da . 44 persons infected with livestock MRSA from mink in three years .