A study of patients at various hospitals in Atlanta has revealed a subpopulation of drug-resistant bacteria that utilize "heteroresistance" to hide among otherwise treatable types of bugs, leading to potentially deadly infections.
Heteroresistant strains of Enterobacter cloacae that are not susceptible to even colisitin, a "last resort" antibiotic, have been causing an increasing number of hospital infections worldwide, according to the study authors. The resistant bacteria were isolated from urine and blood samples containing drug-susceptible bacteria and were found to make up about 5 percent of the total population. The numbers were small enough that the bugs couldn't be detected using a traditional antibiotic-resistance detection test.
The researchers concluded that this type of heteroresistance in bacteria that already do not respond to drug treatment is likely to make hospital infections more difficult to treat. David Weiss, PhD, lead researcher on the study, says the team is working to develop more sensitive diagnostic techniques that could help identify these strains early on in patients with infections.