The most dangerous antibiotic-resistant bacteria are more dynamic, widespread and infectious than previously thought, a new study warns.
CRE (carbapenem resistant Enterobacteriaceae) were last year branded ‘nightmare bacteria’ by CDC director Dr Tom Frieden after proving immune to many last-resort antibiotics.
But a team of Harvard scientists warn new research shows that was a gross understatement.
In an analysis of samples from across the country, the team discovered a much wider variety of CRE species than ever - each species with its own medication-fighting traits.
Worryingly, the species seem to be learning from each other, sharing and spreading medication-resistant genes, some of which have never been seen before.
Worse, the scientists believe CREs may be transmitting from person to person without showing symptoms.
'While the typical focus has been on treating sick patients with CRE-related infections, our new findings suggest that CRE is spreading beyond the obvious cases of disease,' said Dr William Hanage, associate professor of epidemiology at Harvard Chan School and senior author of the study.
'We need to look harder for this unobserved transmission within our communities and healthcare facilities if we want to stamp it out.'
CRE are a class of bacteria that are resistant to multiple antibiotics, including carbapenems, which are considered last-resort drugs when other antibiotics have failed.
CRE, which tend to spread in hospitals and long-term care facilities, cause an estimated 9,300 infections and 600 deaths in the U.S. each year, according to the CDC - and incidence is on the rise.
The researchers looked at about 250 samples of CRE from hospitalized patients from three Boston hospitals and one California hospital.
They had four aims:
*to get a snapshot of CRE's genetic diversity;
*to define how and how often outbreaks occur;
*to document CRE spread within and between hospitals;
*to learn how resistance is being spread among species of CRE.
Previous studies have typically examined just one outbreak at a time.
Researchers found what Dr Hanage termed a ‘riot of diversity,’ both among CRE species and among carbapenem resistance genes.
They also found that resistance genes are moving easily from species to species, contributing to a continually evolving threat from CRE.
In addition, the researchers found resistance mechanisms that hadn't been seen before - implying that there are more to be discovered.
Dr Hanage insists the only way to control the widespread strengthening of CREs is through more genomic surveillance of these dangerous bacteria.
'The best way to stop CRE making people sick is to prevent transmission in the first place,' said Dr Hanage.
'If it is right that we are missing a lot of transmission, then only focusing on cases of disease is like playing Whack-a-Mole; we can be sure the bacteria will pop up again somewhere else.'
— Last Edited by Greentea at 2017-01-17 10:44:02 —