Catheter-related Corynebacterium bacteremia: should the catheter be removed and vancomycin administered?

The purpose of this study was to determine the need for central venous catheter removal in patients with corynebacterial catheter-related bloodstream infections and the impact of central venous catheter retention on response to systemic antibiotic therapy and relapse. We searched the microbiology laboratory database and patients' medical records at our institution between January 2000 and December 2006. We identified 98 patients with corynebacteria infection. Most of the episodes (94%) were catheter-related. Removing the catheter did not affect the outcome of treatment, particularly when an active non-glycopeptide antibiotic was used. All Corynebacterium species isolates were susceptible to vancomycin, 54/55 (98%) to linezolid, 80/95 (84%) to rifampin, and 69/85 (81%) to tetracycline. The median duration of antibiotic therapy was 12 days (range, 0-28), and vancomycin was the most commonly used antibiotic (64%). There was a trend toward earlier fever resolution in patients treated with non-glycopeptide antibiotics compared to vancomycin, particularly if the catheter was not removed. Central venous catheter removal might not be necessary in patients with corynebacterial catheter related bloodstream infection, particularly if systemic therapy consists of non-glycopeptide antibiotics. Treatment with a systemic active antibiotic over a 7-day period appears to be adequate for resolution of the infection.

Inhaled aminoglycosides in cancer patients with ventilator-associated Gram-negative bacterial pneumonia: safety and feasibility in the era of escalating drug resistance.

We sought to evaluate the safety and feasibility of inhaled aminoglycosides or colistin in cancer patients with ventilator-associated pneumonia (VAP) due to Gram-negative bacteria (GNB). A retrospective case-matched study was obtained after obtaining IRB approval in patients at the intensive care unit at our NCI-designated comprehensive cancer center between 1999 and 2005. Sixteen patients with GNB-VAP who received inhaled aminoglycosides or colistin were compared with 16 patients who had received these antibiotics intravenously alone. Eligible patients were required to have received at least six doses of inhaled therapy, or 3 or more days of intravenous therapy. Clinical Pulmonary Infection Scores were used to assess pneumonia severity. Standard ATS criteria were used to define VAP. Patients treated with inhaled antibiotics were less likely to have received corticosteroids (13% vs 50%; P < 0.02) and had a higher median baseline creatinine level (0.85 vs 0.6 mg/dL; P < 0.02) than patients treated intravenously. Pseudomonas aeruginosa (69%) was the most common cause of VAP. There were no serious adverse events associated with inhaled antibiotics. Patients who received these antibiotics intravenously developed renal dysfunction (31%); none of the patients treated with inhaled antibiotics developed nephrotoxicity (P < or = 0.04). Patients treated with inhaled antibiotics were more likely to have complete resolution of clinical (81% vs 31% in the intravenous antibiotic group; P < 0.01) and microbiologic infection (77% vs 8% in the intravenous antibiotic group: P < 0.0006). In a multivariate analysis adjusted for corticosteroid use, inhaled antibiotic therapy was predictive of complete clinical resolution (odds ratio [OR], 6.3; 95% confidence interval [CI], 1.1, 37.6; P < 0.04) and eradication of causative organisms (OR 36.7; 95% CI, 3.3, 412.2; P < 0.003). In critically ill cancer patients with Gram-negative VAP, inhaled aminoglycosides were tolerated without serious toxicity and may lead to improved outcome.

Novel antifungal agents as salvage therapy for invasive aspergillosis in patients with hematologic malignancies: posaconazole compared with high-dose lipid formulations of amphotericin B alone or in combination with caspofungin.

In patients with hematologic malignancy, invasive aspergillosis continues to be associated with high mortality even when treated with conventional antifungal therapy. To investigate novel antifungal agents, we compared 53 patients who received posaconazole salvage therapy to 52 contemporary control patients who received high-dose lipid formulation of amphotericin B (HD-LPD/AMB at > or = 7.5 mg kg(-1) per day) and 38 other control patients who received caspofungin plus HD-LPD/AMB. Patients in the three groups had similar. The overall response rate to salvage therapy was 40% for posaconazole, 8% for HD-LPD/AMB (P < or = 0.001) and 11% for combination therapy (P < 0.002). Aspergillosis contributed to the death of 40% of posaconazole group, 65% of the HD-LPD/AMB group and 68% of the combination group (P < or = 0.008). By multivariate analysis, posaconazole therapy independently improved response (9.5; 95% confidence interval, 2.8-32.5; P < 0.001). HD-LPD/AMB alone or in combination was associated with a significantly higher rate of nephrotoxicity (P < or = 0.02) and hepatotoxicity (P < 0.03). In conclusion, posaconazole salvage therapy demonstrated greater efficacy and safety than HD-LPD/AMB alone or in combination with caspofungin in the salvage therapy of invasive aspergillosis in hematologic malignancy.

Modulation of P-glycoprotein activity by acridones and coumarins from Citrus sinensis.

Bioguided fractionation of the roots of Citrus sinensis (Rutaceae) led to the isolation and identification of five coumarins, namely, clausarin, suberosin, poncitrin, xanthyletin and thamnosmonin, seven acridones, namely, acrimarine B, 2-methoxycitpressine I, citpressine I, buntanine, acrimarine E, honyumine and acrimarine C, and one terpenoid, namely, limonin. Among these compounds, clausarin, 2-methoxycitpressine I and acrimarine E inhibited P-glycoprotein-mediated drug efflux in K562/R7 human leukemic cells over-expressing P-glycoprotein.

Fungal osteoarticular infections in patients treated at a comprehensive cancer centre: a 10-year retrospective review.

This study reviewed retrospectively the clinical characteristics of 28 cancer patients with fungal osteoarticular infections (FOAIs) between 1995 and 2005. Most patients (26; 93%) had haematological malignancies (19 had leukaemia); half (14) were allogeneic stem-cell transplant recipients. Twelve patients (43%) had severe neutropenia (< or = 100/mm3) with a mean duration of 65 days (range 10-500 days), and ten (36%) patients had received a significant dose of corticosteroids. Most (19; 68%) FOAIs were caused by contiguous extension, while nine (32%) were associated with haematogenous spread. Pain, joint instability and local drainage were seen in 28 (100%), six (21%), and seven (25%) patients, respectively. Sixteen (57%) patients had symptoms for < 1 month. The sinuses (ten; 36%) and the vertebral spine (six; 21%) were the most common sites involved. Moulds were the predominant pathogens: Aspergillus fumigatus (two); non-fumigatus Aspergillus spp. (eight); non-specified Aspergillus spp. (three); Fusarium spp. (six); Zygomycetes (five); Scedosporium apiospermum (two); and Exserohilum sp. (one). Candida was the causative pathogen in four cases (including two cases of mixed FOAIs). Arthritis and post-operative FOAIs were both uncommon manifestations, occurring in two patients each. All patients received systemic antifungal therapy (combinations in 20 cases), and 19 cases underwent adjunctive surgery. The crude mortality rates (at 12 weeks) were 44% (9/20) in the patients who underwent surgery and antifungal therapy vs. 33% (2/6) in patients who received antifungal therapy alone (p not significant). FOAI is a rare, yet severe, manifestation of localised or systemic mycoses, caused predominantly by moulds, and is seen typically in patients with haematological malignancies.

Mycobacterium tuberculosis at a comprehensive cancer centre: active disease in patients with underlying malignancy during 1990-2000.

Thirty HIV-seronegative cancer patients with active tuberculosis were evaluated. Eighteen (60%) were immigrants, 19 (63%) had haematological malignancy, and fever was the most common presentation (97%). Of 19 (63%) patients with pulmonary tuberculosis, 11 (58%) were misdiagnosed initially as suffering from cancer following radiography. Death was attributed to tuberculosis for six (21%) of 29 patients who received anti-mycobacterial therapy. All four patients who had received high-dose systemic corticosteroids within 4 weeks of diagnosis of infection died, whereas two (8%) deaths occurred in 25 individuals without corticosteroid exposure (p < 0.001; OR 8.67). At this institution, active tuberculosis was rare, and was seen mostly in immigrants. Recent high-dose corticosteroid therapy is a significant predictor of mortality in cancer patients with tuberculosis.

Mississippi mud in the 1990s: risks and outcomes of vancomycin-associated toxicity in general oncology practice.

BACKGROUND: Discrepancies between the severity of toxicities reported in early clinical trials and recent clinical experience with vancomycin have led to confusion regarding the need for routine serum vancomycin level monitoring and discontinuation of vancomycin when toxicities occur. Therefore, the authors examined the incidence, outcomes, and predictive factors of vancomycin-associated toxicities in general oncology practice with the goal of developing clinically relevant prediction rules and guidelines. METHODS: All 742 consecutive cancer patients who received vancomycin at a comprehensive cancer center during a 3-month period were followed prospectively for the development and outcome of phlebitis, rash, ototoxicity, and nephrotoxicity. Logistic regression was used to derive a multiple variable model of the risk of nephrotoxicity. A clinical prediction rule, the Nephrotoxicity Risk Score, was developed from the risk model and validated prospectively. RESULTS: Phlebitis occurred in 3% of patients (95% confidence interval [95% CI], 2-4%), predominantly those with recently inserted central venous catheters. Rashes occurred in 11% of patients (95% CI, 9-13%); however, all but 4 patients also were receiving beta-lactam antibiotics. Clinical evidence of ototoxicity developed in 6% of patients (95% CI, 4-9%) who were receiving vancomycin plus other ototoxic agents and only 3% of patients (95% CI, 2-5%) not receiving other ototoxic agents (P = 0.08). Nephrotoxicity occurred in 17% of patients (95% CI, 15-20%). Logistic regression revealed that factors associated with an increased risk of nephrotoxicity included administration of other mild to moderate (P = 0.01) or severely nephrotoxic agents (P < 0.001) or an acute physiology and chronic health evaluation (APACHE) score > 40 (P = 0.002). Elevated serum vancomycin peak levels did not reliably predict subsequent nephrotoxicity. CONCLUSIONS: Vancomycin-associated toxicities usually are mild and self-limiting. Some patients are at a significantly higher risk of nephrotoxicity but the authors believe these individuals can be identified reliably with the Nephrotoxicity Risk Index using information available at vancomycin initiation. Further testing of the Nephrotoxicity Risk Index is ongoing.

Minocycline and ethylenediaminetetraacetate for the prevention of recurrent vascular catheter infections.

Three patients with recurrent vascular catheter-related bacteremia were successfully treated by allowing a solution of minocycline and ethylenediaminetetraacetate (EDTA) to dwell in the lumen of the indwelling catheter or by coating polyurethane catheters with minocycline/EDTA and flushing the lumen daily with the same solution. In vitro and in vivo experiments showed that minocycline/EDTA may have broad-spectrum antimicrobial activity, may have optimal anticoagulant activity, and may be highly efficacious in preventing catheter colonization.

In vitro study of the potential role of quinupristin/dalfopristin in the treatment of catheter-related staphylococcal infections.

The susceptibility of clinical isolates of methicillin-susceptible and -resistant staphylococci from cancer patients with central venous catheter bacteremia to quinupristin/dalfopristin, a semisynthetic streptogramin, was determined in vitro. Susceptibility of these isolates to nine other antistaphylococcal antibiotics was also determined for comparison. A total of 197 staphylococcal strains were tested from 1983 to 1992. Quinupristin/dalfopristin was bactericidal against all isolates, independent of their resistance to methicillin. Its activity was similar to that of vancomycin but superior to that of teicoplanin. Quinupristin/dalfopristin may prove to be an important addition to our armamentarium against catheter-related staphylococcal infections.

A comparison of aztreonam plus vancomycin and imipenem plus vancomycin as initial therapy for febrile neutropenic cancer patients.

BACKGROUND: The improved efficacy of imipenem over other beta-lactam antibiotics in the treatment of febrile neutropenic patients has been attributed to its broad spectrum of activity. METHODS: A prospective, randomized, clinical trial was performed comparing vancomycin 1 g every 12 hours plus imipenem/cilassatin 500 mg every 6 hours and the same dose of vancomycin plus aztreonam 2 g every 6 hours for empiric treatment of febrile episodes in neutropenic patients with cancer. RESULTS: The imipenem regimen cured 76% of the 148 evaluable episodes compared with a 67% cure rate for the 152 episodes treated with the aztreonam regimen (p = 0.1). Most of the polymicrobial infections (77% or 10/13) treated with the imipenem responded, whereas only 38% (5/13) of these infections responded to the aztreonam regimen. Although the cost of the imipenem regimen was less than the cost of the aztreonam regimen, it was associated significantly more with skin rashes (12/194 vs 3/189, p = 0.02). In a multivariate analysis, a poor outcome was independently associated in both instances with the persistence of neutropenia and the presence of pneumonia (p < 0.001). CONCLUSIONS: Overall, in a multifactorial analysis that included efficacy, toxicity, and cost, the imipenem and aztreonam regimens were comparable.

Bacteriologic profile of surgical infection after antibiotic prophylaxis.

Wound infections resulting from contamination during major head and neck surgery continue to be a critical issue. In this study, specimens of pus or draining fluids from the wounds of 43 surgical patients who received perioperative administration of ampicillin/sulbactam or clindamycin were cultured for aerobic and anaerobic isolates to species level. Polymicrobial infections were identified in 13 of 43 patients (30%); 82% of isolates were aerobic organisms (45 of 55), and 18% were anaerobic or facultative species (10 of 55). Nine of 43 patients (21%) showed no bacterial isolates from cultured material. Independent of the primary site of malignancy or antibiotics used, nine of 25 isolates (36%) obtained from patients who underwent concomitant dental extractions, but only one of 24 (4%) who did not, developed anaerobic infections, (p < 0.001). The minimum inhibitory concentration of anaerobic isolates suggested sensitivity to the antibiotics used, and minimum bactericidal concentration data suggested that further postoperative doses may be required to adequately treat the heavily contaminated wounds. These data suggest that wound colonization following dental extraction procedures in clean contaminated head and neck surgery increases the risk of anaerobic infections. The use of a therapeutic dose and longer duration of perioperative antibiotics may be warranted.

Low infection rate and long durability of nontunneled silastic catheters. A safe and cost-effective alternative for long-term venous access.

BACKGROUND: Tunneled central venous catheters (CVCs) and infusion ports have often been considered as the only safe alternative for long-term venous access. The objective of this study was to assess the durability, cost, and infection rate of nontunneled, noncuffed Silastic CVCs. METHODS: We studied a representative cohort of 340 consecutive cancer patients with 359 nontunneled Silastic CVCs inserted and followed up at our center. All patients were evaluated clinically and microbiologically at the time of CVC removal. RESULTS: The mean in-place duration of the catheter for the 359 nontunneled CVCs studied was 109 days (total, 39,147 days of catheter use), and the infection rate was 0.13 per 100 catheter days. When compared with the tunneled Hickman catheter, the insertion cost saving was at least $2322 per CVC. At our institution, the use of nontunneled Silastic catheters with the support of an expert infusion team has resulted in an annual cost saving of at least $7,692,000. Long peripheral CVCs (in the basilic/cephalic vein) had a 26% rate of inflammation at the insertion site compared with only 2.6% for the short subclavian CVCs (P < .01). Most of the exit-site inflammations were sterile, with negative skin and catheter cultures. Neutropenia, bone marrow transplantation, high-dose steroids, and use of vesicant chemotherapeutic agents through the CVC did not predispose the patients to catheter infection. By univariate analysis, acute leukemia was the only risk factor for catheter infection. CONCLUSIONS: Given the low infection rate and long durability of nontunneled silicone CVCs, these catheters could offer a cost-effective and safe alternative to surgically implantable tunneled catheters.