SuperbugsAntibiotic-Resistant E coli Found in U.S. Veterinary Hospital
Animals treated in Philadelphia veterinary hospital were found to be infected with a antibiotic-resistant strain of E coli. In the United States, the gene has been detected in only a few human bacterial infections, and never in companion animals. Only a handful of cases in dogs have been reported worldwide.
On 1 April 2019, Shelley Rankin, Ph.D., the chief of clinical microbiology at the University of Pennsylvania’s School of Veterinary Medicine, got a surprising notification from the U.S. Food and Drug Administration (FDA).
Four times a year, Rankin and her colleagues at PennVet ship off bacterial isolates from the school’s veterinary hospitals to the FDA’s Veterinary Laboratory Information and Response Network (Vet-LIRN). PennVet is among a network of veterinary labs across the country that submits animal isolates for antibiotic resistance surveillance and whole-genome sequencing.
CIDRAP reports that the notification Rankin received from Vet-LIRN that day regarded a set of isolates submitted at the end of 2018. Among the isolates was a sample of carbapenem-resistant Escherichia coli from one of a handful of sick cats and dogs treated at PennVet’s Ryan Veterinary Hospital in July and August of 2018.
Since none of the animals had previously been treated with carbapenems, a last-resort antibiotic, Rankin and her colleagues suspected that Vet-LIRN might find a carbapenem-resistance gene in the E coli isolate. But it wasn’t the gene they expected to find.
“Brand New” Vet Medicine Finding
In Philadelphia’s numerous human hospitals, Rankin explained, there’s a reasonably high prevalence of Klebsiella pneumoniae carbapenemase (KPC) genes among patients with carbapenem-resistant and carbapenemase-producing Enterobacteriaceae (CRE and CPE) infections. So they suspected the E coli from the dogs and cats might harbor KPC genes.
But the gene identified by Vet-LIRN was New Delhi metallo-beta-lactamase-5, or NDM-5, a gene that confers elevated resistance to carbapenems. In the United States, the gene has been detected in only a few human bacterial infections, and never in companion animals. Only a handful of cases in dogs have been reported worldwide.
Testing of six more E coli isolates from animals treated at the hospital during the period detected the NDM-5 gene in all of them, and sequencing revealed genetic similarities among the isolates, indicating a unique cluster, or outbreak, of cases.
“We were a little surprised that it was a completely new resistance mechanism for us,” said Rankin. “This is brand new for us in veterinary medicine.”
