How Often Do Clinically Diagnosed Catheter‐Associated Urinary Tract Infections in Nursing Homes Meet Standardized Criteria?

Abstract

Objectives Determine the relationship of clinically diagnosed catheter-associated urinary tract infection (CAUTI) to standardized criteria and assess microorganism-level differences in symptom burden in a cohort of catheterized nursing home (NH) residents. Design Post-hoc analysis of a prospective longitudinal study. Setting Twelve NHs in Southeast Michigan. Participants 233 NH residents with indwelling urinary catheters. Measurements Clinical and demographic data, including CAUTI epidemiology and symptoms, were obtained at study enrollment, 14 days, and monthly thereafter for up to one year. Results One hundred twenty participants with an indwelling catheter (51%) were prescribed systemic antibiotics for 182 clinically diagnosed CAUTIs. Participants were predominantly white (90%), male (52%), with a mean age of 73.7 years. Common signs and symptoms were acute change in mental status (28%), fever (21%), and leukocytosis (13%). Forty percent of clinically diagnosed CAUTIs met Loeb’s minimum criteria, 32% met National Health Safety Network (NHSN) criteria, and 50% met either Loeb’s minimum or NHSN criteria. CAUTIs involving Staphylococcus aureus and Enterococcus spp. were least likely to meet criteria. CAUTIs involving K. pneumoniae were most likely to meet Loeb’s minimum criteria (OR=9.7 [95% CI, 2.3–40.3]), possibly due to an association with acute change in mental status (OR=5.9 [95% CI, 1.8–19.4]). Conclusion Fifty percent of clinically diagnosed CAUTIs met standardized criteria, which represents an improvement in antibiotic prescribing practices. At the microorganism-level, our exploratory data indicates that symptom burden may differ between microorganisms. Exploration of CAUTI signs and symptoms associated with specific microorganisms may yield beneficial information to refine existing tools guiding appropriate antibiotic treatment.

The Pathogenic Potential of Proteus mirabilis Is Enhanced by Other Uropathogens during Polymicrobial Urinary Tract Infection

“…In addition to P. mirabilis, the most prevalent organisms in CAUTIs experienced by nursing home residents in southeast Michigan were Enterococcus species (n ϭ 38 cultures [21%]), E. coli (n ϭ 37 [20%]), and P. aeruginosa (n ϭ 34 [19%]), while P. stuartii was present in only 7 urine cultures (4%) (8). It was therefore critical to test the impact of these organisms on P. mirabilis urease activity during coculture.…”

“…Older adults are at an even higher risk for UTI and CAUTI than younger adults due to several factors, including a higher rate of asymptomatic urine colonization, functional abnormalities, chronic diseases, and certain medications (39). We recently determined that P. mirabilis was the most common organism in CAUTIs experienced by nursing home residents in southeast Michigan, being present in a high percentage of both single-species and dual-species infections (8), which is consistent with the findings of previous studies of catheterized individuals in long-term-care facilities (6,7,40). Infections with P. mirabilis are typically complicated by the formation of bladder and kidney stones and permanent renal damage (9,14,15), there are no currently available vaccines for P. mirabilis, and the incidence of multidrug-resistant isolates is on the rise (41).…”

“…Infections with P. mirabilis are typically complicated by the formation of bladder and kidney stones and permanent renal damage (9,14,15), there are no currently available vaccines for P. mirabilis, and the incidence of multidrug-resistant isolates is on the rise (41). P. mirabilis is also a common constituent of polymicrobial CAUTI (7,8), and there is a growing appreciation for the influence of polymicrobe-host interactions on disease severity (42,43). It is imperative to identify novel targets for the prevention or disruption of P. mirabilis infection, particularly in the context of polymicrobial infection.…”

“…P. stuartii Δure refers to P. stuartii BE2467 lacking the entire urease operon carried by a plasmid (see below). Additional bacterial strains utilized in urease assay experiments were isolated from the urine of catheterized patients in chronic care facilities (6,8,52), with the exception of Acinetobacter baumannii strains ATCC 17978 and AB0057. Bacteria were routinely cultured at 37°C with aeration in 5 ml LB broth (10 g/liter tryptone, 5 g/liter yeast extract, 0.5 g/liter NaCl) or on LB broth solidified with 1.5% agar.…”

“…We recently determined that P. mirabilis is the most common uropathogen in CAUTIs from Michigan nursing home residents, followed by Enterococcus species, Escherichia coli, and Pseudomonas aeruginosa (8). To determine if other uropathogens are capable of enhancing P. mirabilis urease activity, we conducted coculture experiments with both historic and recent clinical isolates from catheterized nursing home residents, including multidrug-resistant isolates and a vancomycin-resistant Enterococcus faecalis isolate (Fig.…”