Prolonged courses of antibiotics can raise the risk of infection.

More than a third of urinary tract infections in nursing home residents are antibiotic-resistant, a new study has found.

Investigators analyzed pathogens and antibiotic susceptibility for nursing home UTI events between January 2013 and December 2017. Data were collected from voluntary reports to the long-term care facility component of the National Healthcare Safety Network. 

Fully 243 nursing homes reported more than 5,400 UTIs during this time period. Nine pathogens accounted for 90% of the infections, the researchers said. “For the resistant phenotypes we assessed, 36% of all UTIs reported were associated with a resistant pathogen,” wrote lead author Taniece Eure, MPH, of the Centers for Disease Control and Prevention.

The three most frequently identified microorganisms were Escherichia coli (41%), Proteus species (14%), and Klebsiella pneumoniae/oxytoca (13%). In cases of E. coli, resistance to the antibiotics fluoroquinolone and extended-spectrum cephalosporin were most prevalent, at 50% and 20% respectively. 

Multidrug resistance was most common in Pseudomonas aeruginosa infections at 11%, and the highest rates of resistance were found for two bacteriums that represented a small percentage (5%) of pathogens reported: Staphylococcus aureus was 67% methicillin-resistant and Enterococcus faecium was 60% vancomycin-resistant.

This is the first summary of antibiotic resistance among common UTI-causing pathogens reported to NHSN by nursing homes, the researchers said. Half of the reporting facilities were nonprofits, median bed size was 91, and average occupancy was 87%. 

The National Healthcare Safety Network is a national healthcare-associated infection tracking system under the auspices of the CDC.

The study was published in the journal Infection Control & Hospital Epidemiology.