By Dr. Geoffrey Modest
Not-so-shockingly, the US government reported the first case of a patient in the US with colistin-resistant E. coli, in a 49 yo Pennsylvania woman with a urinary tract infection. They found a plasmid-mediated piece of DNA which passed along the mcr-1 gene, conferring colistin resistance (see http://www.reuters.com/article/us-health-superbug-idUSKCN0YH2KT . For the case study, see doi:10.1128/AAC.01103-16). This is precisely the issue reported last year in China [see https://stg-blogs.bmj.com/bmjebmspotlight/2015/12/10/primary-care-corner-with-geoffrey-modest-md-troubling-microbiome-changes . This blog looked at the initial report from China, noting that China is the world’s largest producer of poultry and pig products and one of the largest veterinary users or colistin (aka polymixin E), finding this resistant bug in 16 samples from various sites: sputum, urine, ascitic fluid, bile…]. Since the Chinese finding, the Walter Reed National Military Medical Center has been testing all extended-spectrum b-lactamase-producing E. coli for colistin-resistance.
This current finding and the blog (which goes into detail on the China case) basically make the following points:
- Antibiotic resistance is a huge and growing problem: >2 million illnesses blamed on antibiotic resistance in the US with 23,000 annual deaths
- Potential for spread of this E. coli, resistant to the last-line big gun colistin, is real, and highlighted by this case in the US 6 months after the report in China. The concern is that the ability for E. coli to elaborate plasmid-mediated resistance makes it more spreadable than through the prior identified mechanism of chromosomal changes
- Part of the issue is us guys: more than 1/2 of patients admitted to the hospital get an antibiotic, but 30-50% of the time it is considered unnecessary. Blogs below look at the overuse of antibiotics in the outpatient setting as well.
- The biggest part of the problem is use/remarkable overuse of antibiotics in agriculture (as in the colistin case), leading to lots of resistant bugs (see blogs below).
- And there is real concern, as per the CDC, that we may be entering a post-effective antibiotic era
- Confounding the issue, is the lack of aggressive antibiotic development by drug companies: even expensive antibiotics (the $100-200/pill ones) are typically given for short, and therefore less-profitable, courses of treatment. The $$ is in long-term, preferably lifelong need for meds. Some of the big drug companies who mostly foreswore against antibiotic drug development have “signed a declaration calling for new incentives from governments to support investment in development of medicines to fight drug-resistant superbugs”. Perhaps the hepatitis c drug model will develop: hugely overpriced drugs, which even for only a few months can develop huge profits…???
See https://stg-blogs.bmj.com/bmjebmspotlight/category/antimicrobial-resistance/ for a litany of articles/critiques on antibiotic overprescribing, resistance, and efforts to combat resistance, including a US White House report from last year