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ABSTRACTThe increasing incidence of infections caused by multidrug-resistant Pseudomonas aeruginosais a worldwide health problem. Because no new antipseudomonal agents are expected to be available in the near future, we evaluated the safety and efficacy of colistin, an old drug with bactericidal activity against this organism. We collected clinical and demographic data on 95 cancer patients diagnosed with infections caused by multidrug-resistant P. aeruginosabetween January 2001 and January 2004 and treated with either colistin (colistin group) or at least one active antipseudomonal agent (a beta-lactam antibiotic or a quinolone) (control group). We compared the results obtained for both groups. Thirty-one patients had been treated with colistin and 64 had been treated with an antipseudomonal non-colistin-containing regimen. Compared with the control group, patients in the colistin group had a lower median age (52 and 62 years, respectively; P= 0.012) but were more likely to have had nosocomial infections (87% and 64%, respectively; P= 0.02). Twenty-five patients (81%) in the colistin group and 40 patients (63%) in the control group had an APACHE II score of >15 (P= 0.074). The overall clinical response rates were 52% in the colistin group and 31% in the control group (P= 0.055). Multiple logistic regression analysis showed that those patients treated with colistin were 2.9 times (95% confidence interval, 1.1 to 7.6 times) more likely than those in the control group to experience a clinical response to therapy (P= 0.026). Colistin therapy was at least as effective and as safe a beta-lactam antibiotic or a quinolone in the treatment of infections caused by multidrug-resistant P. aeruginosaand, hence, may be a useful or preferred alternative therapy for this infection in cancer patients.

Risk factors for complications of catheter-related Staphylococcus aureusbacteremia (CRSAB) have been studied in the general patient population but have not been well defined in cancer patients. We investigated potential risk factors for intravascular and extravascular complications in these patients. We retrospectively reviewed the records of patients with CRSAB hospitalized at our institution between January 2001 and December 2004. Demographic, clinical, laboratory, and microbiologic characteristics were extracted for the period of hospitalization and up to 3 months thereafter. Intravascular complications were defined as infective endocarditis and/or septic thrombosis. Extravascular complications included septic arthritis, deep tissue abscess, osteomyelitis, septic pulmonary emboli, septic shock, and CRSAB-related death. Ninety-one patients were included in the current study; 63% had solid tumors and the remainder had hematologic malignancies. The incidence of overall complications was 40% (n = 36); 19% (n = 17) were intravascular. On multivariate analysis, renal failure was associated with an increased risk of overall complications (odds ratio OR, 12.78; 95% confidence interval CI, 1.43-114.29; p = 0.0226). Patients with solid tumors were more likely to have intravascular complications (OR, 5.47; 95% CI, 1.11-27.01; p = 0.04369). Risk factors for extravascular complications included hematologic malignancy (OR, 9.56; 95% CI, 2.36-38.77; p = 0.0016) and female sex (OR, 5.25; 95% CI, 1.2-22.99; p = 0.0279). Renal failure is a risk factor for CRSAB complications in patients with cancer. Patients with solid tumors and CRSAB tend to develop intravascular complications, while patients with hematologic malignancies are prone to develop extravascular complications. Hence consideration should be given to extending the duration of therapy beyond 2 weeks.

ABSTRACTTo evaluate the molecular characteristics and antibiotic susceptibility in biofilm of vancomycin-resistant Enterococcus faecium(VREF) organisms that had caused catheter-related VREF bacteremia (VREF-CRB), we compared 22 isolates causing bacteremia obtained from patients with VREF-CRB with 30 isolates from control patients with gastrointestinal colonization by VREF. Using pulsed-field gel electrophoresis, we identified 17 unique strains among the 22 VREF-CRB isolates and 23 strains among the gastrointestinal isolates. The espgene was detected in 53% (9 of 17) of the VREF-CRB and 61% (14 of 23) of the control strains (P= 0.6). VREF-CRB produced heavier biofilm colonization of silicone disks than did control organisms (P< 0.001). Daptomycin, minocycline, and quinupristin-dalfopristin were each independently more active than linezolid in reducing biofilm colonization by VREF-CRB (P< 0.01), with daptomycin being the most active, followed by minocycline. In conclusion, the espgene in VREF is not associated with heavy biofilm colonization or catheter-related bacteremia. In biofilm, daptomycin and minocycline were the most active antibiotics against VREF, and linezolid was the least active.

AbstractObjective:To study the clinical and molecular epidemiology of vancomycin-resistant Enterococcus faeciumorganisms causing catheter-related bacteremia in patients with cancer.Design:Retrospective case-control study.Setting:University of Texas M. D. Anderson Cancer Center, a tertiary-care hospital in Houston, Texas.Patients:Case-patients were patients with cancer who had catheter-related vancomycin-resistant E. faeciumbacteremia and control-patients were patients with cancer and vancomycin-resistant E. faeciumgastrointestinal colonization without infection.Results:Ten case-patients with catheter-related vancomycin-resistant E. faeciumbacteremia were compared with 30 control-patients with gastrointestinal colonization by vancomycin-resistant E. faecium. Patients with catheter-related vancomycin-resistant E. faeciumbacteremia were more likely to have required mechanical ventilation (P< .01), received total parenteral nutrition (P< .01), and had polyurethane catheters (P< .01) inserted in the femoral vein (P= .01). With the use of pulsed-fleld gel electrophoresis, 4 of the 10 catheter-related vancomycin-resistant E. faeciumbacteremia isolates were genetically indistinguishable, whereas only 2 of the 30 control vancomycin-resistant E. faeciumisolates displayed this same DNA pattern (P= .03).Conclusion:This study suggests that catheter-related vancomycin-resistant E. faeciumbacteremia occurs more frequently in patients who receive total parenteral nutrition, mechanical ventilation, and femoral catheters. (Infect Control Hosp Epidemiol 2005;26:658-661)

The efficacy and feasibility of donor granulocyte transfusion therapy (GTX) have changed considerably over the past four decades. The authors sought to determine the impact of high‐dose (approximately 5.5 × 1010 cells) GTX in patients with candidemia.The authors' case–control retrospective analysis comprised 491 consecutive patients treated at The University of Texas M. D. Anderson Cancer Center (Houston,TX) from 1993 to 2000. The cohort included 29 patients with Candida species bloodstream infection who had received GTX and 462 who had not.Both groups were comparable in age, gender, APACHE II score, recent chemotherapy received, broad‐spectrum antibiotics, systemic corticosteroids, radiotherapy, intravascular catheter, and concordant antifungal therapy (P ≥ 0.1). The patients who received GTX compared with those who did not had a higher incidence of underlying leukemia (86% vs. 29%, P < 0.001), persistent neutropenia (59% vs. 18%, P < 0.001), non‐Candida albicans candidemia (Candida glabrata, 35%; Candida krusei, 31%: 90% vs. 67%, P = 0.01), and breakthrough invasive mycosis (62% vs. 23%, P < 0.001). Neutropenia was more prolonged in patients who received GTX (28 vs. 10 days, P < 0.001). Also, more of the patients who received GTX had received hematopoietic stem cell transplantations (28% vs. 13%, P = 0.03), exposure (within 4 weeks) to antifungals (79% vs. 38%, P < 0.001), and stays in critical care units (62% vs. 40%, P = 0.02). The overall attributable mortality rate for 25 evaluable recipients of GTX was 48% (n = 12), compared with 45% (n = 115) of 254 evaluable patients in the control group (P = 0.5). Of the 158 patients with leukemia, 25 (16%) had received GTX. In patients with leukemia, more of those who had received GTX experienced disseminated candidiasis (44% vs. 26%; P < 0.07) and persistent neutropenia (68% vs. 43%, P < 0.02), had candidemia that was more prolonged (> 72 hours, P < 0.02), and had more stays in critical care units (68% vs. 44%, P < 0.03). On the bases of a reduced multivariate model, a significantly increased risk of death was found for patients with hematopoietic stem cell transplantation (odds ratio [OR] = 2.51; 95% confidence interval [95% CI], 0.99–6.31; P < 0.05), for patients with persistent neutropenia (OR = 4.57; 95% CI, 1.99–10.47; P < 0.0003), and for patients with leukemia who also had prolonged candidemia (OR = 3.59; 95% CI, 1.61–7.98; P < 0.002), disseminated candidiasis (OR = 5.19; 95% CI, 2.17–12.42; P < 0.0002), or non‐C. albicans candidemia (OR = 5.02; 95% CI, 1.07–23.64; P < 0.04). In patients with leukemia, death was attributable to candidemia in 50% of the GTX recipients, compared with 59% of the non‐GTX patients who had received antifungal therapy alone (P = 0.4).Despite the presence of multiple predictors of increased mortality, high‐dose GTX therapy in these high‐risk patients with cancer was associated with better than expected survival rates. Cancer 2004. © 2004 American Cancer Society.

Objective:To investigate the epidemiology and environmental sources of Fusarium infections in patients with cancer.Design:Retrospective case-control study conducted following surveillance environmental cultures and DNA analysis of isolated organisms.Setting:A tertiary-care, university cancer center.Methods:In 1996 and 1997, environmental cultures were performed on air samples and water systems. A retrospective chart review was performed for 70 patients with cancer identified with fusariosis between 1987 and 1997. Patients with fusariosis were compared with 49 uninfected control patients who occupied hospital rooms with positive environmental cultures for Fusarium. With the use of random amplification of polymorphic DNA organisms isolated from infected patients were compared with environmental organisms.Results:Most of the patients with Fusarium (40, 57%) were infected on or within 3 days of admission, indicating community rather than nosocomial acquisition. Patients were comparable in terms of underlying immunocompromised status to 49 uninfected control patients. However, the duration from admission to infection in the patients with fusariosis tended to be shorter than the duration from admission to discharge in the exposed control patients (P= .06). Water cultured from the hospital tanks and from sinks and water fountains was negative for Fusarium. With the use of polymerase chain reaction, environmental isolates did not match clinical ones. Quantitative air sampling showed that the quantitative outdoor Fusarium levels were eightfold higher than the indoor levels. During the rainy summer season, outdoor air concentrations of Fusarium were at their highest, coinciding with the peak incidence of fusariosis at our center.Conclusion:The most likely source of fusariosis was the external environment rather than nosocomial sources, such as water.