Proteeae species bacteriuria accompanying Proteeae species groin skin carriage in geriatric outpatients

Abstract

There have been numerous reports of Proteeae species urinary tract infections among elderly individuals. To explore a possible urinary carrier source of Proteeae species in this population, the frequency of aerobic gram-negative bacillus (AGNB) bacteriuria at the greater than or equal to 10(2)/ml level was determined in 67 ambulatory elderly outpatients classified as to Proteeae group (Morganella, Proteus, Providencia) groin carriage by a set of two skin cultures obtained at least 1 week apart. None had urethral catheters, symptomatic infections, skin ulcers, or recent antibiotic therapy. We found AGNB bacteriuria in 12 of 15 carriers (80%) and in 21 of 52 noncarriers (40%) (P = 0.009). Proteeae species bacteriuria occurred in eight carriers (53.3%) and six noncarriers (11.5%) (P = 0.001). At the 10(2) to 10(4)/ml level, Proteeae species were isolated in urine specimens from seven carriers (46.7%) and four noncarriers (7.7%) (P = 0.001). There was concordance of species of skin and urine Proteeae isolates in six carriers. By contrast, non-Proteeae AGNB bacteriuria at any level was present in four Proteeae species carriers (26%) and 15 noncarriers (28.8%) (P greater than 0.05). There was a 36.7% frequency of Proteeae species bacteriuria in nursing home residents, in contrast to 8.1% among those living in private homes; this parallels the greater frequency of Proteeae species groin carriage among nursing home residents in the study population. Low-level urinary colonization with Proteeae species accompanying Proteeae species groin skin colonization in elderly individuals is a hitherto unrecognized finding. This may account for the greater frequency of Proteeae species urinary infections in this population.