Increased Incidence of Urolithiasis and Bacteremia During Proteus mirabilis and Providencia stuartii Coinfection Due to Synergistic Induction of Urease Activity
CE Armbruster, SN Smith, A Yep… - The Journal of …, 2014 - academic.oup.com
The Journal of infectious diseases, 2014•academic.oup.com
Background. Catheter-associated urinary tract infections (CaUTIs) are the most common
hospital-acquired infections worldwide and are frequently polymicrobial. The urease-
positive species Proteus mirabilis and Providencia stuartii are two of the leading causes of
CaUTIs and commonly co-colonize catheters. These species can also cause urolithiasis and
bacteremia. However, the impact of coinfection on these complications has never been
addressed experimentally. Methods. A mouse model of ascending UTI was utilized to …
hospital-acquired infections worldwide and are frequently polymicrobial. The urease-
positive species Proteus mirabilis and Providencia stuartii are two of the leading causes of
CaUTIs and commonly co-colonize catheters. These species can also cause urolithiasis and
bacteremia. However, the impact of coinfection on these complications has never been
addressed experimentally. Methods. A mouse model of ascending UTI was utilized to …
Abstract
Background. Catheter-associated urinary tract infections (CaUTIs) are the most common hospital-acquired infections worldwide and are frequently polymicrobial. The urease-positive species Proteus mirabilis and Providencia stuartii are two of the leading causes of CaUTIs and commonly co-colonize catheters. These species can also cause urolithiasis and bacteremia. However, the impact of coinfection on these complications has never been addressed experimentally.
Methods. A mouse model of ascending UTI was utilized to determine the impact of coinfection on colonization, urolithiasis, and bacteremia. Mice were infected with P. mirabilis or a urease mutant, P. stuartii, or a combination of these organisms. In vitro experiments were conducted to assess growth dynamics and impact of co-culture on urease activity.
Results. Coinfection resulted in a bacterial load similar to monospecies infection but with increased incidence of urolithiasis and bacteremia. These complications were urease-dependent as they were not observed during coinfection with a P. mirabilis urease mutant. Furthermore, total urease activity was increased during co-culture.
Conclusions. We conclude that P. mirabilis and P. stuartii coinfection promotes urolithiasis and bacteremia in a urease-dependent manner, at least in part through synergistic induction of urease activity. These data provide a possible explanation for the high incidence of bacteremia resulting from polymicrobial CaUTI.
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