There is mounting evidence that the ability of germs to resist antibiotic treatment is growing in the U.S., with certain "nightmare bacteria" on the rise. But two antibiotic strategies from nature that have been explored by a few companies may offer alternate approaches to the problem.
Of particular concern are the so-called gram-negative bacilli (GNB) bacteria, which include E. coli, salmonella and Shigella, as well as enterobacteriaceae bacteria. Enterobacteriaceae are a family of more than 70 bacteria including Klebsiella pneumoniae and E. coli that normally live in the digestive system. Over time, some of these bacteria have become resistant to a group of antibiotics known as carbapenems, often referred to as "last-resort" antibiotics.
In March, the Centers for Disease Control and Prevention warned against carbapenem-resistant enterobacteriaceae (CRE), which spread in healthcare facilities and kill up to half of patients who get bloodstream infections from them. They have the potential to kill perfectly healthy individuals and can transfer their resistance to other bacteria within their family.
Moreover, a subsequent report by the Infectious Diseases Society of America (IDSA), published in the journal Clinical Infectious Disease, warned that the seven antibiotic drugs currently in development do not address the entire spectrum of resistance to GNBs. "We're losing ground because we are not developing new drugs in pace with superbugs' ability to develop resistance to them," said Dr. Helen Boucher, lead author of the policy paper and a member of IDSA's board of directors.
Despite the warnings, drug companies seem to be reducing their research efforts for the less profitable antibiotics in favor of cancer and cholesterol treatments. Only four pharmaceutical companies currently are involved in antibiotic research and development. One, Astra Zeneca, has announced it will reduce future investments in antibiotics; another, PolyMedix, recently announced a filing for bankruptcy.
Antibiotic drugs remain the cornerstone of the medical solution strategy, despite that technology appears to be losing the "arms race" against resistant bacteria. The number of approved antibiotics has dropped eightfold since the mid-1980s, and prospects for achieving IDSA's goal of 10 by 2020 are remote.
It should not be so surprising that we're losing this war of numbers with an organism that can spread and mutate over many quickly produced generations. A single bacterium can divide every 20 minutes, becoming 8 million cells in 24 hours The overuse and misuse of antibiotic drugs, particularly in the livestock and poultry industries, has created a vast landscape of artificial selection. The strong have survived the onslaught of our drugs and they have gone on to breed ever-stronger scions, each generation being winnowed for resistance to the drugs.
Next page: Two strategies