Methods: Hospitalized adults with PODU from 1 August 2005- 31 August 2015 at Palmetto Health hospitals in Columbia, SC were identified. PODU was defined based on clinical, radiographic and microbiology criteria. Descriptive statistical methods (Fisher’s exact) were used for preliminary analysis.
Results: 75 cases with PODU were included with a mean age of 53 years and male predominance (48; 64%). The most common comorbidities were paraplegia (45, 60%), diabetes (23, 31%) and previous strokes (17, 23%). 49 cases (65%) received antibiotics within a year of PODU. Prior infections or colonization with P. aeruginosa within the past year was present in 24/75 (32%) cases.
Most cases had multiple sources of cultures: blood (61; 81%); bone/deep tissue (37; 49%) and/or superficial (73; 97%). Among a total of 99 clinical isolates, 56 (57%) were Gram positive cocci (GPC) and 43 (43%) were gram-negative bacilli (GNB). The most common organisms were Enterobacteriaceae (26; 26%), coagulase negative staphylococci (CONS) (20, 20% ), Stapylococcus aureus (19, 19%), [12 (12%) methicillin resistant S. aureus], and P. aeruginosa (9, 9%). Of the Enterobacteriaceae, 69% (18/26) were susceptible to ciprofloxacin and 88% (23/26) to ceftriaxone. All cases (9/9) of PODU due to P. aeruginosa had a prior infection/colonization with P. aeruginosa within 1 year as compared to 15/66 (23%) in those with PODU due to other organisms (p=0.001).
Conclusion: The microbiology of PODU is diverse (including GPC and GNB). Prior positive P. aeruginosa culture was a predictor of P. aeruginosa PODU. When empirical antimicrobial therapy is indicated, data supports the use of intravenous vancomycin plus ceftriaxone in the absence of prior infection/colonization with P. aeruginosa, or intravenous vancomycin plus an anti-pseudomonal agent in the presence of prior P. aeruginosa within the past year.
C. Derrick, None
M. N. Al-Hasan, None
S. Weissman, None
K. Sanasi-Bhola, None