Multi-center evaluation of the VITEK® MS system for mass spectrometric identification of non-Enterobacteriaceae Gram-negative bacilli.

Studies have demonstrated that matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid, accurate method for the identification of clinically relevant bacteria. The purpose of this study was to evaluate the performance of the VITEK MS v2.0 system (bioMérieux) for the identification of the non-Enterobacteriaceae Gram-negative bacilli (NEGNB). This multi-center study tested 558 unique NEGNB clinical isolates, representing 18 genera and 33 species. Results obtained with the VITEK MS v2.0 were compared with reference 16S rRNA gene sequencing and when indicated recA sequencing and phenotypic analysis. VITEK MS v2.0 provided an identification for 92.5 % of the NEGNB isolates (516 out of 558). VITEK MS v2.0 correctly identified 90.9 % of NEGNB (507 out of 558), 77.8 % to species level and 13.1 % to genus level with multiple species. There were four isolates (0.7 %) incorrectly identified to genus level and five isolates (0.9 %), with one incorrect identification to species level. The remaining 42 isolates (7.5 %) were either reported as no identification (5.0 %) or called "mixed genera" (2.5 %) since two or more different genera were identified as possible identifications for the test organism. These findings demonstrate that the VITEK MS v2.0 system provides accurate results for the identification of a challenging and diverse group of Gram-negative bacteria.

Prospective evaluation of unmet needs of rural and aboriginal cancer survivors in Northern British Columbia.

BACKGROUND: The unmet needs of cancer survivors in rural, remote, and aboriginal communities are largely unexplored. We explored potential differences between rural survivors (rss) in 4 general population (gp) and 4 First Nations (fn) communities. METHODS: We approached 4 gp and 4 fn rs communities to participate in a mixed-methods project. Participants completed the Hospital Anxiety and Depression Scale (hads) and the Survivor Unmet Needs Survey (suns) and provided demographic information. Each question on the suns can be scored from 0 to 4, with 0 representing "no unmet need" and 4 representing "very high unmet need." A directed approach to content analysis of focus group and interview data was used to triangulate the hads and suns results. RESULTS: We prospectively accrued 23 fn rss and 56 gp rss for this study. More fn rss had borderline or abnormal anxiety (5% vs. 21%, p = 0.02). Compared with gp rss, fn rss had higher unmet needs scores in all categories: Information (2.29 vs. 0.8, p < 0.001), Work and Financial (1.66 vs. 0.5, p < 0.001), Access and Continuity of Health Care (1.83 vs. 0.44, p < 0.001), Coping and Sharing (2.22 vs. 0.62, p < 0.001), and Emotional (2.12 vs. 0.63, p < 0.001). The qualitative findings provided examples and insight into the unmet needs experienced by rss. CONCLUSIONS: First Nations rss had significantly higher anxiety and unmet needs compared with their gp rs counterparts. In addition, different qualitative themes were identified in the groups. Our findings support the development of tailored approaches to survivorship for these populations.

Identification of Enterobacteriaceae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using the VITEK MS system.

This multicenter study evaluated the accuracy of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry identifications from the VITEK MS system (bioMérieux, Marcy l'Etoile, France) for Enterobacteriaceae typically encountered in the clinical laboratory. Enterobacteriaceae isolates (n = 965) representing 17 genera and 40 species were analyzed on the VITEK MS system (database v2.0), in accordance with the manufacturer's instructions. Colony growth (≤72 h) was applied directly to the target slide. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry before mass spectrometry analysis. On the basis of the confidence level, the VITEK MS system provided a species, genus only, or no identification for each isolate. The accuracy of the mass spectrometric identification was compared to 16S rRNA gene sequencing performed at MIDI Labs (Newark, DE). Supplemental phenotypic testing was performed at bioMérieux when necessary. The VITEK MS result agreed with the reference method identification for 96.7% of the 965 isolates tested, with 83.8% correct to the species level and 12.8% limited to a genus-level identification. There was no identification for 1.7% of the isolates. The VITEK MS system misidentified 7 isolates (0.7 %) as different genera. Three Pantoea agglomerans isolates were misidentified as Enterobacter spp. and single isolates of Enterobacter cancerogenus, Escherichia hermannii, Hafnia alvei, and Raoultella ornithinolytica were misidentified as Klebsiella oxytoca, Citrobacter koseri, Obesumbacterium proteus, and Enterobacter aerogenes, respectively. Eight isolates (0.8 %) were misidentified as a different species in the correct genus. The VITEK MS system provides reliable mass spectrometric identifications for Enterobacteriaceae.

Patients With a Prolonged Intensive Care Unit Length of Stay Have Decreased Health-Related Quality of Life After Cardiac Surgery.

Cardiac surgery patients with a prolonged ICU length of stay (prICULOS) have lower rates of functional survival following their procedure, however detailed information on their health related quality of life (HRQoL) is lacking. We sought to investigate the potential need for intervention in these high-risk patients through comprehensive HRQoL assessments in the months to year following their surgery. A prospective, observational pilot study was undertaken and cardiac surgery patients with a prICULOS (ICU length of stay of ≥5 days) were recruited. A control group was obtained through recruitment of cardiac surgery patients with an ICU length of stay of <5 days. In-person clinical or telephone survey HRQoL assessments were completed at 3-6 months and 1-year time points after their procedure. The standardized mean difference (SMD) was calculated for all study variable comparisons to quantify the standardized effect size observed between non-prICULOS and prICULOS patients. 789 cardiac procedures were performed during the study period and 89 patients experienced a prICULOS (10.7%). Of these 89 patients, 35 prICULOS patients were recruited along with 35 controls. 29 out of 35 prICULOS patients completed the study (83%). At the 3-6 month follow up the prICULOS patients had higher levels of weight loss, fear of falling, and driving deficits. At 1-year, prICULOS patients had persistent difficulties with activities of daily living and required more family and external support. This study demonstrates the need for closer follow up and intervention for cardiac surgery patients with a prICULOS who were found to have poorer mid and long-term HRQoL.

Rivaroxaban for treatment of suspected or confirmed heparin-induced thrombocytopenia study.

UNLABELLED: Essentials Heparin-induced thrombocytopenia (HIT) is a thrombogenic condition that is difficult to treat. We evaluated rivaroxaban as a treatment option in patients with suspected or confirmed HIT. One patient had recurrent thrombosis and 9/10 patients with thrombocytopenia had platelet recovery. Rivaroxaban may be an effective and safe treatment option for HIT. SUMMARY: Background Rivaroxaban is a direct oral anti-Xa inhibitor that has the potential to greatly simplify treatment of heparin-induced thrombocytopenia (HIT). Objectives To evaluate the efficacy and safety of rivaroxaban in this patient population, we conducted a multicenter, single-arm, prospective cohort study of patients with suspected or confirmed HIT. Patients/Methods Twenty-two consecutive adults with suspected or confirmed HIT received rivaroxaban 15 mg bid until a local HIT assay result was available. Participants with a positive local assay result continued rivaroxaban 15 mg bid until platelet recovery (or until day 21 if they had acute thrombosis at study entry), then stepped down to rivaroxaban 20 mg daily until day 30. Results and Conclusions The primary outcome measure, incidence of new symptomatic, objectively-confirmed venous and arterial thromboembolism at 30 days, occurred in one HIT-positive participant (4.5%; 95% confidence interval [CI], 0-23.5%) and one HIT-positive participant required limb amputation despite platelet recovery. Platelet recovery was achieved in nine out of 10 HIT-positive patients with thrombocytopenia. Rivaroxaban appears to be effective for treating patients with confirmed HIT, although the small number of patients enrolled limits precision.

HLA class II alleles associated with susceptibility and resistance to Crohn's disease in the Jewish population.

Previous studies have suggested that susceptibility to Crohn's disease (CD) is associated with the histocompatibility complex (HLA) class II alleles DR1, DQ5, and DR13 in the Caucasian population, DR7 in the French and German populations, and DR4 and DQ4 in the Japanese population. However, little is known about the relationship between HLA class II alleles and CD in the Jewish population since these previous studies included few Jewish individuals. In order to determine whether the HLA associations observed with predominantly non-Jewish populations were also present in the Jewish CD population and whether there were any HLA class II alleles uniquely associated with CD in the Jewish population, 132 CD patients, of which 82 were Ashkenazi Jewish, were HLA-typed using serologic and DNA methods. Ethnically matched controls were similarly typed. No association with DR1 or DR13 was observed in the Jewish CD population although an association with DR13 (OR [odds ratio] = 5.3, p = 0.02) was observed in the non-Jewish CD population. However, an association with DR15 (OR = 2.7, p = 0.03), which is normally associated with ulcerative colitis, was observed in the Jewish, but not non-Jewish, CD group. In addition, a strong negative association was observed with DR3, which was especially striking in the Jewish population (OR = 0.35, p = 0.025); similar negative associations with DR3 have been observed by others using non-Jewish populations. Furthermore, a significant negative association with DR7 (OR = 0.45, p = 0.04) was observed in the Jewish, but not non-Jewish, population. Consistent with this was the negative association with DQ2 (OR = 0.38, p = 0.005), which is in strong linkage disequilibrium with both DR3 and DR7, in the Jewish, but not non-Jewish, population. These studies support previous suggestions that susceptibility to CD in Jewish and non-Jewish populations is determined by distinct genes and provide further support to the hypothesis that a gene on the DR3 haplotype may protect against CD. Furthermore, protection is conferred by the same or another gene found on Jewish, but not non-Jewish, DR7 haplotypes.

Repair of articular cartilage defects using mesenchymal stem cells.

Degeneration of articular cartilage in osteoarthritis is a serious medical problem. We have isolated a population of cells from the connective tissue of mammals termed mesenchymal stem cells (MSCs) for their apparent unlimited growth potential and their ability to differentiate into several phenotypes of the mesodermal lineage, including cartilage and bone. These qualities make them ideal candidates for cartilage repair. We isolated MSCs from adult rabbit muscle and cultured them in vitro into porous polyglycolic acid polymer matrices. The matrices were implanted into 3-mm-diameter full thickness defects in rabbit knees with empty polymer matrices serving as the contralateral controls. The implants were harvested 6 and 12 weeks postop. At 6 weeks, the controls contained fibrocartilage while the experimentals seemed to contain undifferentiated cells. By 12 weeks postop, the controls contained limited fibrocartilage and extensive connective tissue, but no subchondral bone. In contrast, the implants containing MSCs had a surface layer of cartilage approximately the same thickness as normal articular cartilage and normal-appearing subchondral bone. There was good integration of the implant with the surrounding tissue. Implantation of MSCs into cartilage defects appears to effect repair of both the articular cartilage and subchondral bone. Studies are ongoing to further characterize the use of MSCs for cartilage repair.

Multi-centre evaluation of mass spectrometric identification of anaerobic bacteria using the VITEK® MS system.

Accurate and timely identification of anaerobic bacteria is critical to successful treatment. Classic phenotypic methods for identification require long turnaround times and can exhibit poor species level identification. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an identification method that can provide rapid identification of anaerobes. We present a multi-centre study assessing the clinical performance of the VITEK(®) MS in the identification of anaerobic bacteria. Five different test sites analysed a collection of 651 unique anaerobic isolates comprising 11 different genera. Multiple species were included for several of the genera. Briefly, anaerobic isolates were applied directly to a well of a target plate. Matrix solution (α-cyano-4-hydroxycinnamic acid) was added and allowed to dry. Mass spectra results were generated with the VITEK(®) MS, and the comparative spectral analysis and organism identification were determined using the VITEK(®) MS database 2.0. Results were confirmed by 16S rRNA gene sequencing. Of the 651 isolates analysed, 91.2% (594/651) exhibited the correct species identification. An additional eight isolates were correctly identified to genus level, raising the rate of identification to 92.5%. Genus-level identification consisted of Actinomyces, Bacteroides and Prevotella species. Fusobacterium nucleatum, Actinomyces neuii and Bacteroides uniformis were notable for an increased percentage of no-identification results compared with the other anaerobes tested. VITEK(®) MS identification of clinically relevant anaerobes is highly accurate and represents a dramatic improvement over other phenotypic methods in accuracy and turnaround time.

Clinical evaluation of NucliSENS magnetic extraction and NucliSENS analytical specific reagents for the real-time detection of respiratory syncytial virus (RSV) in paediatric respiratory specimens.

AIMS: To evaluate the combination of NucliSENS magnetic extraction and NucliSENS analytical specific reagents (bioMérieux, Marcy L'Etoile, France) for the detection of respiratory syncytial virus (RSV) from a variety of respiratory samples. METHODS: Nucleic acids (NA) from paediatric samples (n = 603) and an RSV-specific inhibition control (R-IC) were coextracted using the miniMAG and/or the easyMAG. Nucleic-acid-sequence-based amplification (NASBA) and molecular beacon detection of RSV and R-IC were performed using NucliSENS analyte-specific reagents (NRSVA) and the NucliSENS EasyQ Analyzer. NRSVA results were compared with R-Mix culture and direct fluorescent antibody detection (DFA). RESULTS: The NRSVA analytical specificity was 100%, and the NRSVA limit of detection was 5-20 RNA copies/reaction. The prediscordant analysis, sensitivity, specificity, PPV and NPV were, respectively, for R-Mix (64.7%, 100%, 100%, 94.5%); DFA (98.8%, 99.0%, 94.4%, 99.8%); NRSVA (94.1%, 95%, 75.5%, 99%). After discordant analysis, sensitivity, specificity, PPV and NPV were, respectively, for R-Mix (56.7%, 100%, 100%, 92.3%); DFA (87.6%, 99.2%, 95.5%, 97.7%); NRSVA (93.8%, 97%, 85.9%, 99%). RSV was detected in 17.8% of the samples and in seven coinfections. Children with proven RSV infection, compared with children without a pathogen identified, had shorter median hospitalisation stays (2 days vs 3 days, p = 0.035), used fewer antibiotics (54% vs 69%) and had shorter durations of antibiotic therapy (6.2 days vs 9.3 days, p = 0.021), respectively. CONCLUSIONS: NRSVA is sensitive and specific for RSV detection in respiratory samples. The R-IC monitored the test process, including NA extraction, target amplification and detection. The rapid detection of respiratory pathogens can foster appropriate patient management.

Evaluation of matrix scaffolds for tissue engineering of articular cartilage grafts.

Injury to articular cartilage predisposes that joint to further degeneration and eventually osteoarthritis. Recent studies have demonstrated the feasibility of using chondrocytes together with different biomaterial carriers as grafts for the repair of cartilage defects. The following study was undertaken to determine the effect of a variety of these materials on chondrocyte growth and extracellular matrix synthesis. We cultured chondrocytes on several commonly used materials and compared their rates of synthesis of proteoglycan and collagen. Additionally, we evaluated them in a closed culture recirculating system on these materials and compared them with standard culture techniques. This was done to see whether such a bioreactor-type system can be used to enhance the quality of in vitro reconstructed tissues. Our results demonstrated marked variability with respect to how chondrocytes responded to culture on the various materials. Bioabsorbable polymers such as polyglycolic acid (PGA)--enhanced proteoglycan synthesis, whereas collagen matrices stimulated synthesis of collagen. The use of the closed culture system, in general, improved the rates of synthesis of collagen and proteoglycan on the different material scaffolds. Exceptions were collagen synthesis on collagen matrices: use of the closed culture system did not enhance the rate of synthesis. Rates of proteoglycan synthesis on PGA scaffold initially was higher in the closed culture system but did not sustain a difference over the entire course of the 3-week culture period. This study demonstrates the importance of carrier material for the purpose of cartilage tissue reconstruction in vitro.