Scientists have discovered a troubling bacteria that appears to be resistant to the antibiotic of last resort. The bacteria is a Klebsiella, which causes more infections than the less-common type of bacteria, Enterbacter.
|Bacteria resistant to last-resort antibiotic, missed by standard tests|
Emory microbiologists have detected “heteroresistance” to colistin, a last-resort antibiotic, in already highly resistant Klebsiella pneumoniae, a bacterium that causes blood, soft tissue and urinary tract infections.
The results are scheduled for publication in mBio.
David Weiss, PhD, director of the Emory Antibiotic Resistance Center, and his colleagues had observed heteroresistance to colistin in other bacteria, called Enterobacter, previously.
Carbapenem-resistant Enterobacteriaceae (CRE), which include Klebsiella, were listed as one of the top three urgent antibiotic resistant threats in 2013 by the Centers for Disease Control and Prevention. Various types of Klebsiella are estimated to be responsible for 10 percent of infections acquired in health care facilities.
“This is concerning because Klebsiella is a more common cause of infection than Enterobacter, and these isolates were carbapenem-resistant, which means that they might actually be treated with colistin,” says Weiss, professor of medicine at Emory University School of Medicine and Emory Vaccine Center. “To our knowledge, this type of heteroresistant Klebsiella has not been observed in the United States before.”
The first author of the paper is Immunology and Molecular Pathogenesis graduate student Victor Band. Co-authors include Sarah Satola, PhD, Eileen Burd, PhD, Monica Farley, MD and Jesse Jacob, MD. Burd is director of clinical microbiology lab at Emory University Hospital and Farley is director of the Department of Medicine’s Division of Infectious Diseases. Weiss’s lab is based at the Yerkes National Primate Research Center, Emory University.
The bacterial isolates came from urine samples from two patients in Atlanta-area hospitals as part of the nationwide Multi-site Gram-Negative Surveillance Initiative, part of the CDC-funded Emerging Infections Program.