Carbapenemase-producing Enterobacteriaceae and non-Enterobacteriaceae from animals and the environment: an emerging public health risk of our own making?

Acquired carbapenemases pose one of the most pressing public health threats relating to antibiotic resistance. In most countries, the number of carbapenemase-producing bacteria from human clinical specimens is rising, and the epidemiological status of these multiresistant bacteria is progressively worsening. Furthermore, there is a growing number of reports of carbapenemases found either in bacteria isolated from non-human sources or in Salmonella enterica subsp. enterica, a zoonotic species. However, carbapenemases are not yet systematically sought in bacteria from non-human sources, reports of them are largely observational, and there is limited investigation of carbapenemase-positive bacteria in animals and possible links with people who may have acted as potential sources. Active surveillance and monitoring for carbapenem-resistant bacteria in the food chain and other non-human sources is urgently needed, with an enhanced and rigorous follow-up of all positive results. The carbapenems are currently our last good defence against multiresistant Gram-negative bacteria. Our ability to limit the rise and spread of carbapenemase producers, which occur only at basal levels in many countries at present, should serve as a key performance indicator for the success or failure of the efforts that have been called for by international organizations and governments to reduce the impact of antibiotic resistance.