Antibiotic Resistance on Factory Farms Devon Byrne

Overview… Conditions of factory farms - why do they use antibiotics? How does bacteria become resistant? How do humans get it? Human health consequences Direct effects on the environment What is being done?

Factory Farms Antibiotics are injected or orally administered to animals Animals routinely given antibiotics to promote growth prevent diseases (unsanitary, stressed, crowded conditions) treat infections

Factory Farms and Antibiotics The same antibiotics used in factory farms are used on humans penicillin, tetracycline, erythromycin, etc. Antibiotics kill the non-resistant bacteria and leave behind the resistant bacteria to multiply Resistant bacteria multiply in the animal Bacteria ready to be passed on to humans

Misuse and Overuse In conventional agriculture, antibiotics are considered food additives, not drugs, and can be purchased “over the counter” ~90% of all veterinary drugs are administered without professional consultation or approval ~70% of antibiotics used in U.S. are fed to factory farmed animals (cattle, poultry, pigs) Globally, half of all antibiotics are used towards agriculture

So what’s the problem?? "Antibiotic resistance is an inevitable consequence of [antibiotic] use, the more you use them the more resistance you will get.” - Associate Professor Collignon

Resistant Bacteria Bacteria can be… naturally resistant or acquire a genetic mutation that resists antibiotics Resistant bacteria produces enzymes that can… inactivate antibiotic alter antibiotic target site

http://www.textbookofbacteriology.net/ResistanceMechanisms.gif

How do humans get the resistant bacteria? Direct contact with animals Infected farms workers can then pass the resistant bacteria onto others Drinking contaminated water Manure can leak from factory farm lagoons into groundwater and waterways Eating under cooked meat Transfer of genes between animal and human bacteria

Human Health Consequences Children and people with weakened immune systems are most vulnerable Superbugs Food borne pathogenic (disease-causing) bacteria (Salmonella, Campylobacter, Enterococcus) are becoming increasingly resistant to classic antibiotic treatments

Fluoroquinolone-resistant Salmonella (ERS) Baytril, an antibiotic used in poultry, similar to human drug, Cipro, used to treat urinary tract infections, food poisoning Resistance to Cipro has increased 21% since its approval for use in poultry production in 1995 FDA believes ~5000 people affected annually by resistant salmonella

MRSA: Methicillin-resistant Staphylococcus aureus Staph infection that doesn’t respond to antibiotics Causes skin infections that can spread throughout body (potential to be life threatening) Common in hospitals, but now showing up more in community settings According to a European study, community-aquired cases of MRSA can be attributed to factory farms Responsible for ~19,000 US deaths in 2005 May surpass death toll from AIDS

Direct Effects on Environment Factory farm runoff contaminated with antibiotics Remaining in environment for long periods of time Disrupts the natural balance of bacteria Resistant strains outweigh nonresistant Antibiotics easily carried by wind and water “The biosphere is a diluted solution of tetracycline” - Stanley Falkow (Prof. of Microbiology at Stanford School of Medicine) Effects uncertain

What is being done to keep antibiotics working? 1978: FDA begins to express concern but overpowered by producers and pharmaceuticals 2003: McDonald’s pledges to only buy poultry not routinely given antibiotics for growth purposes 2006: EU bans adding antibiotics to animal feed for growth purposes 2007: Preservation of Antibiotics for Medical Treatment Act (U.S.) “phase out feeding food animals massive quantities of antibiotics important in human medicine”

What can we do? Cook meat thoroughly in order to kill bacteria Eat meat that is antibiotic free Don’t eat meat at all Wash your hands to avoid passing on bacteria

References APUA. "Antibiotics in the Ecosystem." Alliance for the Prudent Use of Antibiotics. 1999. 8 Dec. 2008 <http://www.tufts.edu/med/apua/ecology/eia.html>. Australian Broadcasting Company. "How bacteria become resistant." Millenium Bugs. 1999. 8 Dec. 2008 <http://www.abc.net.au/science/slab/antibiotics/resistance.htm>. Lewis, Ricki. "The Rise of Antibiotic-Resistant Infections." 1995. US Food and Drug Adminstration. 8 Dec. 2008 <http://www.fda.gov/fdac/features/795_antibio.html>. Millman, Suzanne. "The Emerging Threat of Antibiotic Resistance: A Hidden Cost of Factory Farming." Spring 2002. 8 Dec. 2008 <http://www.hsus.org/press_and_publications/humane_society_magazines_and_newsletters/all_animals/volume_4_issue_1_spring_2002/the_emerging_threat_of_antibiotic_resistance_a_hidden_cost_of_factory_farming.html>.

References Continued… Mlot, Christine. "Antibiotic Resistance." Controversies in Science and Technology : From Maize to Menopause. Ed. Daniel Kleinman, Jo Handelsman and Abby J. Kinchy. New York: University of Wisconsin P, 2005. Truant, Patti. "Agricultural Use of Antibiotics Prompts Human Health Concerns: FDA Bans Controversial Poultry Drug." MedScape Today. 6 Jan. 2006.WebMD.8 Dec. 2008 <http://www.medscape.com/viewarticle/520518>. Union of Concerned Scientists. "European Union Bans Antibiotics for Growth Promotion." Food & Agriculture. 14 Feb. 06. 8 Dec. 2008 <http://www.ucsusa.org/food_and_agriculture/solutions/wise_antibiotics/european-union-bans.html>. World Health Organization. "Use of antimicrobials outside human medicine and resultant antimicrobial resistance in humans." Media Centre. Jan. 2002. 8 Dec. 2008 <http://www.who.int/mediacentre/factsheets/fs268/en/index.html>.

Questions?