Evolving trends in multiple-antibiotic-resistant bacteria in liver transplant recipients: a longitudinal study of antimicrobial susceptibility patterns.
The incidence, sources, impact on outcome, and temporal trends in multiple-antibiotic-resistant bacteria in liver transplant recipients over the last decade (from 1990 through 1999) were assessed. Of 165 consecutive patients who underwent transplantation, 31% (51 of 165 patients) had at least 1 infection caused by multiple-antibiotic-resistant bacteria. Overall, 69% (66 of 96 infections) of all bacterial infections were multiple-antibiotic resistant. Ninety-one percent (45 of 49 isolates) of the Staphylococcus aureus isolates, 50% (6 of 12 isolates) of the enterococci, and 54% of the gram-negative bacteria (47%; 7 of 15 Pseudomonas aeruginosa, and 60%; 12 of 20 Enterobacteriaceae) were multiple-antibiotic resistant. A significant trend toward an increase in infections caused by multiple-antibiotic-resistant bacteria (P =.003), largely caused by an increase in gram-positive infections, was documented through the decade. There was a significant increase in infections caused by methicillin-resistant S aureus (P =.0001) and vancomycin-resistant enterococci (P =.04) over time. The proportion of gram-negative isolates that were multiple-antibiotic resistant (P =.447) did not increase significantly over time. However, a strikingly high frequency of resistance to piperacillin or ceftazidime suggests that extended-spectrum beta-lactamase production in our Enterobacteriaceae may have been more prevalent than realized. Mortality at 1 year was significantly greater in patients with multiple-antibiotic resistant bacteria compared with all other patients (P =.001). These longitudinal trends have implications not only for guiding therapeutic practices, but ultimately for devising strategies to curtail multiple-antibiotic resistance in liver transplant recipients.
Singh
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N
Infectious Disease Section, Veterans Affairs Medical Center, Pittsburgh, PA 15240, USA. nis+@pitt.edu
Gayowski
T
T
Rihs
J D
JD
Wagener
M M
MM
Marino
I R
IR
D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D004755:Enterobacteriaceae / Q000187:drug effects / Q000302:isolation & purification; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D016031:Liver Transplantation; D008137:Longitudinal Studies; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D020713:Vancomycin Resistance