Recent surveillance from US hospitals shows that more than 99.5% of vancomycin-resistant enterococci (VRE) isolates remain susceptible to daptomycin. This report describes emergence of daptomycin-resistant VRE at a major cancer center. The percentage of patients with daptomycinresistant VRE bacteremia increased from 3.4% in 2007 to 15.2% in 2009 (P = .03). Without susceptibility data, empiric daptomycin therapy for VRE infections should be used with caution.Vancomycin-resistant enterococci (VRE) were first isolated in the United States in the late 1980s and have spread widely in the ensuing years. The most recent National Nosocomial Infection Surveillance (NNIS) report showed that 28.5% of all enterococcal isolates are resistant to vancomycin. 1 Studies have shown poorer clinical outcomes among patients with VRE infections when compared with those infected with vancomycin-susceptible enterococci. 2 In the past decade, 4 new drugs with activity against VRE have been licensed for use: quinupristin-dalfopristin (1999), linezolid (2000), tigecycline (2005), and daptomycin (2003). Few studies have examined and compared the efficacy of these agents for use in the treatment of VRE infections. Among the newer drugs, common adverse effects such as myelotoxicity (linezolid) and myalgias (quinupristin-dalfopristin) limit the use in certain circumstances, especially among patients undergoing treatment for cancer.Recent surveillance studies from US hospitals have demonstrated that more than 99.5% of VRE isolates remain susceptible to daptomycin. 3 The purpose of this report is to describe the recent emergence at our hospital of daptomycin-resistant VRE strains. METHODSWe examined the daptomycin susceptibility profile of all isolates collected during episodes of VRE bacteremia at Memorial Sloan-Kettering Cancer Center (MSKCC) from January (CDC), Atlanta, Georgia, using the broth microdilution method (cation-adjusted MuellerHinton broth). Pulsed-field gel electrophoresis (PFGE) was performed after SmaI digestion and interpreted according to criteria previously described. 5 Statistical analysisPoisson regression was used to perform time-trend analysis on VRE healthcare-associated infection (HAI) rates from 2005 through 2009. The proportion of isolates resistant to daptomycin was analyzed using the Cochran-Armitage test for linear trend. A P value ≤.05 was considered statistically significant. All analyses were performed using SAS, version 9.1 (SAS Institute). Of 18 patients with daptomycin-resistant VRE bacteremia, 15 (83%) had underlying hematologic malignancy (Table 1), 16 (89%) had no prior exposure to daptomycin, and 2 patients had received daptomycin for 5 and 17 days before the diagnostic culture sample was obtained. Of the 18 patients, 11 (61%) had mixed bacteremia, with isolation of daptomycinsusceptible and daptomycin-resistant strains during the same episode. Of these, only 1 had received daptomycin before or during the VRE bacteremia episode. RESULTS FromIsolates from 14 of the 18 patients with daptomycin-res...

An evaluation of the Luminex NxTAG Respiratory Pathogen Panel was performed on 404 clinical respiratory specimens. Clinical sensitivities and specificities of the assay compared to those of the reference methods were 80.0% to 100.0% and 98.9% to 100.0%, respectively. Correct genotyping information was provided for 95.5% of influenza virus A specimens. The closed-tube format of the assay simplified the workflow and minimized carryover contamination.

We compared the performance characteristics of culture and the Cepheid Xpert vanA assay for routine surveillance of vancomycin-resistant enterococci (VRE) from rectal swabs in patients at high risk for VRE carriage. The Cepheid Xpert vanA assay had a limit of detection of 100 CFU/ml and correctly detected 101 well-characterized clinical VRE isolates with no cross-reactivity in 27 non-VRE and related culture isolates. The clinical sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert vanA PCR assay were 100%, 96.9%, 91.3%, and 100%, respectively, when tested on 300 consecutively collected rectal swabs. This assay provides excellent predictive values for prompt identification of VRE-colonized patients in hospitals with relatively high rates of VRE carriage. Vancomycin-resistant enterococci (VRE) are recognized as nosocomial pathogens alongside methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. Vancomycin resistance in enterococci species is conferred mainly by the presence of the vanA or vanB gene, although the presence of other genes, including vanC, vanD, vanE, and vanG, can also result in a resistant phenotype (7,25). In North America, the vanA gene is the most prevalent resistance marker in enterococci species, followed by the vanB gene, which can be found in bacteria other than enterococci (4, 10). Both the vanA and vanB genes are carried on transposable plasmids, and transfer of these plasmids to other enterococci and S. aureus has been shown both in vitro and in vivo (7).Several reports have shown that in allogeneic hematopoietic stem cell transplant recipients, VRE colonization, prior to stem cell transplantation, is a significant risk factor for the development of VRE bacteremia, which is associated with poor clinical outcomes (3,14,22,24). In order to decrease the spread of VRE in hospital settings, the Hospital Infection Control Practices Advisory Committee (HICPAC) recommends a multipronged approach that includes rapid identification and reporting of VRE-positive stools or rectal swabs by the microbiology laboratory in order to ensure prompt isolation of colonized patients (2).Currently, VRE surveillance is performed at our institution using traditional culture. This procedure requires 48 to 96 h to obtain a final result and involves multiple media and incubation steps. Recently, the Food and Drug Administration (FDA) approved a rapid molecular assay, the Xpert vanA (Cepheid, Sunnyvale, CA), for the detection of VRE directly from rectal swab specimens only. The assay is a real-time, one-step PCR assay performed on the GeneXpert instrument and provides results in less than 1 h, compared to 48 to 96 h with culture. In addition to providing rapid results for timely isolation of colonized patients, rapid and more sensitive detection of VRE may also result in the timely identification of patients at risk for the development of VRE bacteremia. The objective of the present study was to evaluate the performance characteristics of this novel P...

Invasive fungal infections (IFI) remain a serious threat to immunocompromised hosts. Current diagnostic methods, including fungal culture and antigen detection, are slow and often lack specificity. Rapid diagnostic tools with increased sensitivity and specificity could improve the care of patients with IFI. Recently, Luminex Molecular Diagnostics (Toronto, Canada) developed 23 analyte-specific reagents (ASRs) for the detection of the most common clinically relevant fungi. This study's objective was to evaluate the sensitivity and specificity of a subset of these ASRs for fungal isolates and clinical specimens. Previously characterized fungal and bacterial isolates (n ‫؍‬ 110), blood culture specimens (n ‫؍‬ 34), and respiratory specimens (n ‫؍‬ 44) were tested using either a Candida 7-plex panel (Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida lusitaniae, Candida guilliermondii, and Candida krusei) or a mold 11-plex panel (Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Scedosporium prolificans, Scedosporium apiospermum, Fusarium oxysporum/Fusarium solani, Rhizopus arrhizus, Rhizopus microsporus, Mucor indicus, and Cunninghamella bertholletiae). The Candida 7-plex panel correctly identified all Candida isolates as confirmed by fungal culture and biochemical tests, for a sensitivity and specificity of 100%. The mold 11-plex panel correctly identified all mold isolates tested except for A. niger. Fungal isolates of Rhizopus and Mucor species were not detected, either, although they could represent species other than those targeted by the ASRs. Further evaluation will be necessary to confirm the sensitivities of some of the mold ASRs. Implementation of these ASRs will allow same-day detection of fungal DNA in clinical specimens.Invasive fungal infections (IFI) remain a major cause of morbidity and mortality in immunocompromised hosts. In patients undergoing hematopoietic stem cell transplantation (HSCT), the timing for the acquisition of an IFI differs with the type of transplant (autologous versus allogeneic HSCT) and the type of IFI (candidiasis versus aspergillosis) (24). A recent article by the Transplant-Associated Infection Surveillance Network (TRANSNET) reported that the 12-month cumulative incidence for IFI in HSCT was 3.4%, with a range of 0.9 to 13.2% and an overall 1-year survival rate ranging from 6.3% to 33.6% depending on the cause of IFI (16). The most common cause of IFI was invasive aspergillosis (most commonly Aspergillus fumigatus), followed by invasive candidiasis (most commonly Candida glabrata) and mucormycosis (formerly zygomycosis) (16). These cases included only proven and probable fungal infections as defined by the Mycoses Study Group and the Cooperative Group of the European Organization for Research and Treatment of Cancer (EORTC) (2).Diagnosis of IFI currently relies on the recovery of molds or yeasts in culture, fungal stains, detection of antigens, including galactomannan and ␤-D glucans, and various radiologic...

hWe explored the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for identification of Fusobacterium nucleatum subspecies. MALDI-TOF MS spectra of five F. nucleatum subspecies (animalis, fusiforme, nucleatum, polymorphum, and vincentii) were analyzed and divided into four distinct clusters, including subsp. animalis, nucleatum, polymorphum, and fusiforme/vincentii. MALDI-TOF MS with the modified SARAMIS database further correctly identified 28 of 34 F. nucleatum clinical isolates to the subspecies level. Fusobacterium nucleatum is an opportunistic pathogen, associated with various forms of periodontal diseases and extraoral infections, as well as colorectal cancer (1, 2). F. nucleatum is a highly heterogeneous species and was classified into five subspecies: animalis, nucleatum, polymorphum, vincentii, and fusiforme (3-5). Recent studies based on phylogenetic analysis of the nucleic acid sequences of 16S rRNA, rpoB, zinc protease, and 22 other housekeeping genes suggested that F. nucleatum subsp. fusiforme and vincentii be classified into a single subspecies, F. nucleatum subsp. fusiforme/vincentii (4, 5).Different subspecies may vary in pathogenesis relating to different levels of disease activity (6-8). Fusobacterium nucleatum subsp. nucleatum is isolated mostly in periodontal diseased sites, whereas F. nucleatum subsp. fusiforme/vincentii is often isolated from healthy sites as normal flora (9). F. nucleatum subsp. animalis and polymorphum are associated with pregnancy complications (7), and F. nucleatum subsp. animalis is also associated with inflammatory bowel disease (10). Until now, molecular technologies have been the most effective and widely accepted tools for subspecies identification (3,4,11). At the subspecies level of F. nucleatum, the sequence divergences of 16S rRNA genes were only 0.6% to 1.9%, so full-length sequencing of 16S rRNA was desirable (4).This study aimed to explore the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of F. nucleatum at the subspecies level. A commercially available database was amended using 15 F. nucleatum isolates comprising the type strains and other wellcharacterized clinical isolates of the five subspecies and then tested for rapid identification of F. nucleatum subspecies.(This study was presented in part at the 113th (10). A total of 34 F. nucleatum clinical isolates were collected from Case Western Reserve University, Memorial Sloan-Kettering Cancer Center, Harvard University School of Public Health, and bioMérieux, Inc. The isolates were stored in Trypticase soy broth with glycerol at Ϫ80°C, cultivated on Columbia agar (Becton, Dickinson and Company, Sparks, MD) supplemented with 5% sheep blood, and incubated at 37°C for 48 h in an anaerobic chamber, as previously described (10).Full-length 16S rRNA gene sequencing. Bacterial DNA was extracted from a pure colony with a Pure Link genomic DNA minikit (Invitrogen, Carlsbad, CA). The 16S ...