The United States government proposed several important steps last week that, if accomplished, will significantly change how this country attempts to counter the advance of antibiotic resistance, bringing us within reach of the more complete programs which exist in Europe. But as significant as it is, the new program has some perplexing gaps that left experts attending to the issue disappointed.
Big news in the world of food policy, farming and antibiotic use: Perdue Farms, the third-largest chicken producer in the United States, announced today that during the past decade it has ceased using most of the antibiotics that formerly propped up its chicken production.
There are caveats to that “most,” and I’ll explain them. But it’s important to say up front that this is a nationally significant move and looks like an industry-leading step.
The farm practice that underlies most agricultural use of antibiotics is known as “growth promotion”: It calls for giving very small doses of antibiotics routinely to meat animals because those doses cause them to gain fat and muscle more quickly than they would otherwise. Growth promotion dates back to the early days of the antibiotic era, and has always been somewhat mysterious. Though there were attempts to pick apart its mechanisms in the 1950s and 1960s (I’ve been reading some fascinating old accounts), for the most part, people simply accepted that it worked. It’s only in the past decade or so, as interest has increased in the microbes that reside everywhere in our and animals’ bodies (a vast community generally known as the microbiome), that researchers have begun trying to dissect what is going on.
The scientific team that has probably pursued this most intensely is the NYU Langone Medical Center lab led by Martin J. Blaser. Blaser published a popular account of their research into antibiotics’ effect on obesity, asthma, diabetes, and other disorders in Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues, published in April. (Disclosure: I reviewed the book for Nature.) Two years ago, the team showed that giving small doses of antibiotics to very young mice affected genes controlling metabolism of nutrients, and caused the mice to gain weight. Now they have followed up that research with detailed work exploring how much the timing and length of antibiotics affects weight gain. Though the work is still in mice, it leads to provocative conclusions about how growth promoters work in livestock, and what early-life antibiotics might do to humans as well.
Among the groups that work on awareness of antibiotics resistance — which include major medical and public health organizations as well as nonprofits trying to direct attention to antibiotic misuse in medicine and agriculture — there has been a lot of anticipation of a forthcoming report by the President’s Council of Advisors on Science and Technology. The report, which has been in the works for months, will be published shortly, possibly as early as next week. Today, the council — known as PCAST for short — held a public meeting to discuss the report’s contents and vote as a group to accept or rejected. The meeting was webcast, and as far as I could tell, the vote was unanimous.
Though the report itself won’t be out for a bit, the meeting gave a good sense of what the report will say. For accessibility, PCAST runs live voice-recognition transcription of its meetings; so while the meeting was proceeding, I grabbed a transcript to review later. Here’s what seems to be coming.
A newly formed international organization — more than 700 members in 55 countries — has launched an urgent appeal to governments and healthcare, begging for attention to antibiotic resistance as a grave global threat, and asking that antibiotics be declared a cultural heritage deserving legal protection.
The group grew out of meetings by French and other European researchers, and all its materials are bilingual, to the point that it is going by two names and acronyms: the World Alliance Against Antibiotic Resistance (WAAAR) and L’alliance contre le développement des bactéries multi-résistantes (AC2BMR).
The group has been in formation a while but went public Monday, publishing its appeal and asking for 10 specific actions to keep antibiotic resistance from surging beyond the point at which it can be controlled.
Breaking news today from the Centers for Disease Control and Prevention, out of its open-access journal Emerging Infectious Diseases: Researchers in Canada have identified a very highly resistant bacterium in squid imported from South Korea and being sold in a Chinese grocery store.
The letter reporting the finding was supposed to go live at noon ET, but hasn’t yet. When it does, it will be linked from this page, under the subheading Letters. It is titled: “Carbapenamase-Producing Organism in Food, 2014.”
A troubling and also kind of odd story came out of Denmark this weekend. In a court proceeding, a microbiologist has disclosed that three residents of the country who had no known connection to farming died of MRSA infections caused by ST398, the livestock-associated strain of drug-resistant staph that first appeared among pig farmers in the Netherlands in 2004 and has since moved through Europe, Canada and the United States.
If the report is correct — and sources have told me it is, but I’ve seen no data to confirm it — it reinforces the concern that bacteria which become resistant because of antibiotic use on farms can move off farms and affect the health of people who have no connection to farming.
Livestock MRSA has always one of the best cases for establishing that, because the drug to which it showed the greatest resistance, tetracycline, wasn’t used against human MRSA in the Netherlands, but was used routinely on farms — so the only place the strain could have picked up its unique resistance pattern was in pigs. (Here’s my long archive of posts on pig MRSA, dating back to my book Superbug where the story was told for the first time.)
The World Health Organization has released a significant report marking what I think must be the first attempt to quantify antibiotic resistance globally. It’s a very sobering read — not just for what the data says about the advance of resistance worldwide, but also because of what the organization could not say, because the data doesn’t exist.
The numbers themselves are unsettling. Dr. Keiji Fukuda, the WHO’s assistant director general, told the press: “It’s clear that rates are very high of resistance among bacteria causing many of the most common serious infections – the ones that we see both occurring in the community as well as in hospitals … In all regions of the world, we now see that hospitals are reporting untreatable, or nearly untreatable, infections.”
But the gaps in the numbers are too: There are 194 member countries in the WHO, but only 114 had the data-gathering resources to contribute something to the report, and only 22 were able to send in data on the most important occurrences of resistance in very common bacteria. Thus it’s possible that the report could be an under-estimate, or an over-estimate. But I can’t think of a scenario in which it could be considered substantially inaccurate. Its portrait of a world in which antibiotic resistance is advancing to grave proportions ought to be taken seriously.
A paper published this week reminded me to take a fresh look at NDM, the “Indian superbug” — actually a gene and enzyme — that got so much attention, including from me, in 2011. (Most of the posts are here.) Quick reminder: NDM surfaced in 2008 in Sweden, then was found in the United Kingdom, then in the United States and then elsewhere in the world. It had several distinctive qualities. It appeared in gut bacteria such as Klebsiella and E. coli, and caused infections when those bacteria escaped the gut and got elsewhere in the body. It rendered those bacteria not-vulnerable to almost all antibiotics, leaving so few drugs to use against it that medical personnel found it truly alarming. And it had strong links to South Asia: The first known patient was an Indian man living in Sweden who had gone home for a visit and been hospitalized; victims found later either had family links to India and Pakistan or had gotten medical care there, as medical tourists or because they were injured while traveling.
NDM (which stands for New Delhi metallo-beta-lactamase; it was originally NDM-1, but there are now at least seven variants) generated a lot of alarm at the time, with good reason. Its unusual resistance pattern made useless the last category of broad-spectrum, last-resort antibiotics, called carbapenems, that were still working reliably. Physicians treating patients who had infections involving NDM had to hunt among just a few remaining drugs that were still on the shelf because they were toxic or did not work reliably. Plus, because bacteria carrying the NDM resistance factor colonize the gut, the infection could be transported across borders and into hospitals without anyone noticing. With no symptoms showing, few hospitals would bother to check a patient (or a family member), especially since testing for gut bacteria is more complicated and intimate than, for instance, testing someone’s nostrils for MRSA.
By last year, NDM had mostly dropped out of the headlines, even though it was still moving across the globe (this 2013 paper details countries where it has been identified), and had also begun causing hospital outbreaks (for instance, this one in Denver in 2012). So the new paper I mentioned, written by staff from Public Health England and analyzing the first 250 patients with NDM in the UK, is a useful reminder of how formidable a microbiologic foe this can be.
Double-barreled news today from the US Centers for Disease Control and Prevention. In an analysis of several sets of hospital data, gathered by the agency and also purchased from independent databases, the CDC said it found that more than 37 percent of prescriptions written in hospitals involved some sort of error or poor practice, increasing the risk of serious infections or antibiotic resistance. And in a surprise announcement timed to the release of the federal draft budget, the agency said it is in line to receive $30 million to enhance its work combating antibiotic resistance in the US.