844 - Nosocomial Pseudomonas aeruginosa Blood-Stream Infections; Susceptibility Pattern and Mortality at a Tertiary Care Centre in Edmonton, Alberta, Canada

Background: Pseudomonas aeruginosa is one of the leading gram negative nosocomial pathogens, causing severe infections including blood-stream infections (BSI) with high mortality rates. (1). Multi-drug resistant P. aeruginosa (MDRPA) infection rates are reported to be increasing (2) and have been associated with increased mortality (3). This study aims to review the susceptibility pattern and trend of P. aeruginosa BSIs and mortality and identify patients at increased risk of BSI with a resistant P. aeruginosa isolate. This data has important treatment implications.

Methods: Cases of nosocomial P. aeruginosa bacteremia were prospectively identified at the University of Alberta, Edmonton, Alberta, Canada by the infection prevention and control surveillance program between January 1, 2007 and December 31, 2018. Patient charts were retrospectively reviewed to collect microbiological, clinical, and epidemiological information.

Results: 148 cases of P. aeruginosa BSI were identified over a 12-year period between January 2007 and December 2018. There were 19 cases of MDRPA BSI and 9 cases of XDRPA BSI. The incidence of P. aeruginosa BSI was 0.47 per 10,000 patient days and remained relatively stable over the study period. 66.9% of cases occurred in men. The mean age was 60 years. The average length of stay prior to bacteremia was 42 days. The overall 30-day mortality following P. aeruginosa BSI was 36.4%. Risk factors for increased 30-day mortality included: pulmonary source of infection (OR 4.26, p < 0.001), bacteremia with extremely drug resistant Pseudomonas aeruginosa (XDRPA) (p < 0.0001), and diabetes (OR 2.24, p < 0.05). BSI with MDRPA was not an independent risk factor for increased mortality. Significant risk factors for bacteremia with an MDRPA or XDRPA were length of stay > 28 days (OR 4.22, p < 0.001) and hemodialysis (OR 8.92, p < 0.000001).Annual hospital acquired P. aeruginosa blood-stream infections from 2007-2018
Antibiogram of P. aeruginosa blood-stream isolates from 2007-2018


Conclusion: The incidence of P. aeruginosa BSI as well as the rate of MDRPA and XDRPA BSI have remained stable at our centre between 2007 and 2018. We found that BSI with XDRPA but not MDRPA alone was a significant risk factor for mortality. Risk factors for BSI with a resistant P. aeruginosa strain may be considered to guide empiric therapy.