Summary
Highlights
For the past two years, the documentary has investigated the emergence and spread of nightmare bacteria, or superbugs, that are increasingly resistant to the strongest antibiotics. These bacteria, such as KPC and NDM-1, are defeating drugs, causing over 20,000 deaths and 2 million illnesses annually. This growing problem is fueled by the overuse of antibiotics, creating untreatable pathogens.
A significant portion of antibiotics are used on farms, not by humans. A North Georgia farm, under anonymity, demonstrates how antibiotics are essential for industrial-scale farming. Veterinarian Chuck Hofaker explains their goal is disease prevention in large chicken populations, using antibiotics like 'Linky' in drinking water or feed. An estimated 70% of US antibiotics are sold to farms, contributing to faster growth and cheaper food, but raising concerns about antibiotic resistance transferring to humans.
Scientists are trying to determine if antibiotic use on farms contributes to human antibiotic resistance. In Flagstaff, Arizona, hospitals have seen a rise in resistant urinary tract infections. Genetic researcher Lance Price sampled supermarket meat in Flagstaff to investigate if resistant bacteria from farms are ending up on our plates. He hypothesizes that contaminated food could be a source of drug-resistant E. coli causing human infections, noting that systemic infections from resistant E.coli can lead to sepsis.
Antibiotics were first used on animals in the 1940s, coinciding with the industrialization of agriculture. Increased animal confinement led to higher disease transmission, which antibiotics initially seemed to 'fix'. A significant unintended benefit was faster growth and increased productivity, making meat cheaper. However, as early as the 1960s, the British government's 'Swan Report' warned about antibiotic resistance as a consequence of using antibiotics for growth promotion, though a direct link to human illness was not definitively established at the time.
Researchers in central Pennsylvania, including Joan Casey and Brian Schwarz, are studying how antibiotic resistance might travel through the environment. They found a significant rise in MRSA infections in this region, particularly among young, healthy individuals, and noted a correlation between these infections and the proximity to large pig farms. Their theory proposes that MRSA from pig manure, loaded with undigested antibiotics and resistant bacteria, can become airborne or wash into local water systems, potentially reaching nearby residents.
Farmers and drug makers dismiss the studies as speculative due to lack of direct testing of manure and the difficulty of proving a definitive link. The CDC acknowledges the presence of resistance in animals, humans, and retail meat but highlights the challenge in tracing a specific instance of animal antibiotic use to a human illness. In 1977, FDA Commissioner Donald Kennedy attempted to restrict penicillin and tetracycline use in animals due to concerns about resistance, but strong opposition from farm lobbies and industry, supported by influential Congressman Jamie Whitten, led to the proposal being shelved due to a perceived lack of 'smoking gun' evidence.
Veterinarians Guy Loneragan and Morgan Scott discovered that using tetracycline, an older antibiotic, in cattle—intended to preserve the effectiveness of cephalosporins—actually led to an increase in resistance to cephalosporins. This unforeseen outcome supported the 1977 FDA's concern that even seemingly less critical antibiotics could accelerate overall resistance, highlighting a complex link between different antibiotic types despite initial assumptions.
Lance Price's study in Flagstaff found that 20% of tested meat contained dangerous E. coli, with a third of those being highly resistant. Using whole genome sequencing, he's genetically linked over 100 human urinary tract infections back to supermarket meat, suggesting a common origin, likely the farm. However, a significant gap remains: data on antibiotic usage on farms is not publicly available or collected, hindering a complete understanding of the resistance pathways.
There is a significant lack of data regarding antibiotic use in animals, including specific volumes for different animals or purposes. Despite calls from government and academic institutions for this data to understand resistance, it is not currently collected. FDA Commissioner Margaret Hamburg acknowledges the need but emphasizes moving forward. Recent proposals in Congress to mandate reporting were opposed by industry groups, viewing them as attempts to restrict antibiotic use. The FDA has since adopted a voluntary approach, asking pharmaceutical companies to discontinue selling antibiotics for growth promotion, expecting compliance within three years and increased veterinary oversight. Critics argue this voluntary measure, without mandatory data collection, may be insufficient to address the 88% of antibiotic use not tied to growth promotion and question its effectiveness and oversight.
After 40 years, antibiotic use in agriculture and human antibiotic resistance have both significantly increased. The documentary concludes that we live in a shared environment where bacteria move freely between animals and people, making the route of transmission less important than the fact of movement itself. This interconnectedness underscores the critical need for comprehensive strategies to combat antibiotic resistance.