The salmonella outbreak that rippled out from California chicken processing facilities last year, sickening more than 400 and hospitalizing at least 134, came with a troubling footnote: Several bacteria samples taken from victims resisted multiple types of antibiotics.
They weren’t impervious to salmonella drugs, officials from Foster Farms are quick to point out, and no one has died. Officials conducting an investigation have yet to discern the precise causes of the outbreak.
But the presence of antibiotic-resistant bacteria underscored concerns about new mutations of bacteria arising and afflicting humans. One of the medical breakthroughs of the 20th century, antibiotics have been victims of their own success, losing effectiveness as they have become ubiquitous medical tools.
“Any time you use an antibiotic, either in an animal or in a human, you are going to put pressure on those bacteria and you are going to create a resistance,” said Dr. Tom Chiller, a medical epidemiologist for the federal Centers for Disease Control and Prevention. “We know resistance is occurring across the food chain, really from farm to fork, and we know humans can become sick from those bacteria.”
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Now California legislators are invoking public health as they seek limits on feeding antibiotics to livestock. They cite science that links overuse of antimicrobial drugs on farm animals to the prevalence of hardier bacteria.
“It’s a problem that I think we’re seeing more effects of,” said Sen. Jerry Hill, D-San Mateo.
Hill and Assemblyman Kevin Mullin, D-South San Francisco, have introduced bills that would restrict the use of antibiotics on livestock. Both lawmakers point to a growing body of evidence indicating that overuse of livestock antibiotics – often to help animals gain weight – has allowed drug-resistant bacteria to prosper and spread.
“There’s clearly a public health concern with the overuse of antibiotics,” Mullin said in an interview, and “we need to take a bold step now.”
Food producers have access to a range of different antibiotics, but the drugs can be divided into three broad categories: antibiotics used to treat an existing health issue; antibiotics used to guard against outbreaks, introduced before animals have fallen sick; and antibiotics used for “production purposes,” to help animals bulk up more quickly or with less food.
Representatives for California’s agriculture sector and its $2.8 billion cattle industry question the charge that farmers and ranchers habitually use antibiotics to fatten up their animals. While they support using antibiotics judiciously, they say food producers need the ability to swiftly treat ill animals.
“We really don’t want to use antibiotics, because that means we’ve got sick animals,” said Dave Daley, second vice president of the California Cattlemen’s Association. But “we want to make sure antibiotics, as needed, can be used by small farmers and ranchers to care for cattle that are truly sick.”
Antibiotic-resistant bacteria represent a serious issue: the Centers for Disease Control estimates they infect more than 2 million Americans a year, killing at least 23,000 of them. A recent CDC report warning of the perils of overuse noted that the amount of antibiotics given to livestock “contributes to the emergence of antibiotic-resistant bacteria in food-producing animals.”
Consequences of the drug-defying bacteria can include lengthened hospital stays and treatment methods that carry higher costs and more potential side effects, according to Avinash Kar, a staff attorney for the Natural Resources Defense Council.
“The antibiotic-resistant bacteria, once they’re generated and thrive on these facilities, can get out in a variety of ways,” including by permeating soil and water or migrating to workers, said Kar, whose organization is actively backing Mullin’s bill.
The federal Food and Drug Administration has spotlighted antibiotic resistance as a significant public health risk. In December, the agency released voluntary guidelines that would have pharmaceutical companies change how they label drugs, effectively prohibiting farmers from using antibiotics to promote growth.
Both bills before the Legislature would go further. Hill’s approach would build on the FDA advisory but make its recommendations mandatory, taking a tougher approach to banning over-the-counter weight-gain antibiotics.
“I think the FDA did not go far enough in their voluntary requirements,” Hill said. “You make them voluntary, there’s not a real incentive to focus on curtailing the use of antibiotics.”
Drug companies have said they will comply with the FDA’s framework, and the new guidelines are subject to a public comment period that ends in mid-March.
Assemblyman Frank Bigelow, R-O’Neals, said his colleagues should wait for the FDA process to play out before advancing additional regulations.
“There’s a hysteria that starts to occur, and people jump on bandwagons without knowing all the facts or looking at all the facts,” said Bigelow, a cattleman identifiable on the Assembly floor by his distinctive white rancher’s hat. “We already have an agency, the FDA, who has the oversight powers,” he added, “and we need to let them use those powers.”
Even more stringent than Hill’s proposal is Mullin’s bill, which would ban weight-gain antibiotics and sharply restrict access to the preventive kind.
Under the current system farmers and ranchers can obtain preventive antibiotics, intended to pre-emptively stem the spread of diseases like pneumonia, over the counter. The FDA has proposed having veterinarians sign off.
But making that oversight optional, as the FDA framework does, is not enough, according to Mullin. His bill would bar preventive use of antibiotics except in limited cases where there is documented risk of a sick animal infecting other animals.
To Mullin and allies, keeping those preventive antibiotics widely available would preserve a loophole.
“I’m concerned that, essentially, we’re not getting at the core problem and would still have a high volume of antibiotics in the food supply” if preventive use isn’t scaled back, Mullin said.
Beyond that, Kar said, some large producers use preventive drugs to compensate for cramped or unclean conditions that help incubate disease.
“It would really limit the circumstances when antibiotics are used to what we think are the appropriate uses: when the animal is sick or when there’s an outbreak on the premises that needs to be contained,” Kar said of Mullin’s bill. “It shouldn’t be because you’re raising the animals in crowded, unsanitary conditions.”
Building a barrier to obtaining preventive medicine is short-sighted, according to Noelle Cremers of the California Farm Bureau Federation. Cremers said the tightened standards Mullin proposes will delay treatment, comparing it to forcing a family to wait for a doctor to make house calls.
“Farmers and ranchers want to make sure that antibiotics remain effective for human health and animal health,” Cremers said, but “there’s a recognition that we need to prevent disease, and antibiotics applied through feed can do a really good job of preventing disease.”
California is in the midst of another withering drought, with dry grass leaving cattle more susceptible to respiratory issues and other problems, according to Daley of the California Cattlemen’s Association. Policymakers must give food producers the autonomy they need to keep their animals healthy, Daley said.
“Frankly, most cattlemen don’t want to see indiscriminate use of antibiotics, either,” Daley said, but “we need the flexibility to be able to use them when we need them.”