A new, drug-resistant strain of E. coli, that a recent study hit upon, is causing serious antimicrobial-resistant infections in the US.
The new strain, ST131 has been reported in multiple countries and encountered all over the United States.
In the study, researchers analyzed resistant E. coli isolates collected during 2007 from hospitalized patients across the country. They identified 54 ST131 isolates, which accounted for 67 percent to 69 percent of E. coli isolates exhibiting fluoroquinolone or extended-spectrum cephalosporin resistance.
In the past, highly virulent E. coli strains usually have been susceptible to antibiotics, while highly resistant strains have been fairly weak in terms of their ability to cause disease.
The susceptible strains were easily treated even though they caused serious infections, while the resistant ones tended mostly to affect only weakened or vulnerable individuals. Now, the study's findings suggest, the ST131 strain has appeared with a high level of virulence and antimicrobial resistance.
"If this strain gains one additional resistance gene," Dr. Johnson added, "it will become almost untreatable and will be a true superbug, which is a very concerning scenario."
The findings were published in the Clinical Infectious Diseases.