We evaluated the reliability of the Bruker Daltonik's MALDI Biotyper system in species-level identification of yeasts directly from blood culture bottles. Identification results were concordant with those of the conventional culture-based method for 95.9% of Candida albicans (187/195) and 86.5% of non-albicans Candida species (128/148). Results were available in 30 min (median), suggesting that this approach is a reliable, time-saving tool for routine identification of Candida species causing bloodstream infection.
We report the first comparative evaluation between the Bruker Biotyper MS (BMS) and the Vitek MS (VMS) for the identification of yeasts. The rate of correct identifications at the species level was comparable using the commercial databases (89.8% versus 84.3%; P ؍ 0.712), but higher for BMS using an in-house-extended database (100% versus 84.3%; P ؍ 0.245). Importantly, the rate of misidentification was significantly higher for VMS (1% versus 12.1%; P < 0.0001), including the rate of major errors (0% versus 4.5%; P ؍ 0.0036). The introduction of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in the clinical microbiology laboratories is changing the approach to bacterial and fungal identification (1-4). In particular, several studies have already demonstrated the reliability of MALDI-TOF MS in the rapid identification of yeasts in different clinical settings (5-7), evidencing its cost-effectiveness in allowing the initiation of species-targeted antifungal therapy (7-9). To date, four MALDI-TOF MS systems are commercially available: the Microflex LT Biotyper (Bruker Daltonics, Bremen, Germany) (BMS), the Saramis system (bio-Mérieux, Marcy l'Etoile, France), the Vitek MS system (bioMérieux, Marcy l'Etoile, France) (VMS), and, very recently, the Andromas system (Andromas, Paris, France). Several comparative studies have already been performed using the most common systems (BMS and VMS), but, to the best of our knowledge, they have focused only on the identification of bacteria (10-13). Only very recently was a comparative study on yeasts performed using BMS and Saramis (bio-Mérieux, Marcy l'Etoile, France), the previously distributed version of VMS (14). In the present study, we evaluated the ability of BMS and VMS to identify a broad panel of yeasts of medical interest.One hundred ninety-seven isolates from different human samples, previously identified by conventional biochemical techniques or by sequencing the internal transcribed spacer 1 (ITS1) and ITS2 regions, were blindly identified using the two systems. In order to minimize the risk of misidentification related to the use of incomplete and error-filled public databases (15), the sequences obtained were compared to reference data available in two databases: GenBank, searched by using the nucleotide BLAST tool (blast.ncbi.nlm.nih.gov), and the CBS (Centraalbureau voor Schimmelcultures) yeast database (www.cbs.knaw.nl). The panel included 157 (79.7%) isolates belonging to 30 Candida or Candida-related species (Table 1), and 40 (20.3%) isolates belonging to 15 non-Candida species (Table 2). Before processing for MS identification, each isolate was cultured on Sabouraud dextrose (Kima, Padua, Italy) agar and incubated for 24 h at 35°C. For BMS, proteins were extracted as recommended by the manufacturer. Briefly, a loopful of yeasts was suspended in one volume of water and three volumes of absolute ethanol, and after centrifugation, the pellets were processed with an equal amount of formic acid and acetonitrile ...
Our aims were to identify (i) risk factors associated with the acquisition of multidrug-resistant (MDR, to 3 or more classes of antimicrobials) Proteus mirabilis isolates responsible for bloodstream infections (BSIs) and (ii) the impact on mortality of such infections. Risk factors for acquiring MDR P. mirabilis BSIs were investigated in a case-case-control study; those associated with mortality were assessed by comparing survivors and nonsurvivors in a cohort study. The population consisted of 99 adult inpatients with P. mirabilis BSIs identified by our laboratory over an 11-year period (1999 to 2009), 36 (33.3%) of which were caused by MDR strains, and the overall 21-day mortality rate was 30.3%. Acquisition of an MDR strain was independently associated with admission from a long-term care facility (odds ratio to which the isolate displayed in vitro resistance) more frequently than those with non-MDR infections; they also had increased mortality and (for survivors) longer post-BSI-onset hospital stays. In multivariate regression analysis, 21-day mortality was associated with septic shock at BSI onset (OR, 12.97; 95% CI, 32.2 to 52.23), P. mirabilis isolates that were MDR (OR, 6.62; 95% CI, 16.4 to 26.68), and IIAT (OR, 9.85; 95% CI, 26.7 to 36.25), the only modifiable risk factor of the 3. These findings can potentially improve clinicians' ability to identify P. mirabilis BSIs likely to be MDR, thereby reducing the risk of IIAT-a major risk factor for mortality in these cases-and facilitating the prompt implementation of appropriate infection control measures. The Gram-negative enteric bacterium Proteus mirabilis is an important cause of community-and health care-associated infections, including those involving the urinary tract, the abdominal cavity, and the bloodstream itself (13,19,50). Like many other members of the family Enterobacteriaceae, P. mirabilis can harbor numerous plasmid-and integron-mediated determinants of antimicrobial resistance (18). Multidrug-resistant (MDR) strains of P. mirabilis generally produce extended-spectrum -lactamases (ESBLs) or the AmpC-type cephalosporinase and rarely carbapenemases, and their prevalence in some settings is relatively high (8,10,12,13,25,31,39,41).Over the past decade, the proportion of BSIs caused by Gramnegative bacteria has risen sharply (11,26,38,51). Although 1 to 3% of all BSIs are caused by P. mirabilis (11,26,38,51), the incidence of MDR in the strains responsible for these infections is a cause for concern. In general, MDR infections are known to have a significant impact on the prognosis and survival of hospitalized patients (9,14,24,42,43,46), but it is unclear whether MDR strains are associated with worse clinical outcomes in P. mirabilis BSIs. Endimiani et al. (13) found that treatment failure and death are likely to occur in ESBL-producing P. mirabilis BSIs. Unfortunately, this study was small, including 23 patients and only 9 patients with ESBL BSIs. However, we can reasonably assume that empirical therapy is even more likely to be inadequate...
A single-test QFT-based screening strategy for LTBI in psoriasis patients receiving long-term anti-TNF-alpha treatment could reduce the incidence of false-positive LTBI cases, preventing unnecessary TB chemoprophylaxis.
Mannose-binding lectin (MBL) plays a key role in the human innate immune response. It has been shown that polymorphisms in the MBL2 gene, particularly at codon 54 (variant allele B; wild-type allele designated as A), impact upon host susceptibility to Candida infection. This systematic review and meta-analysis were performed to assess the association between MBL2 codon 54 genotype and vulvovaginal candidiasis (VVC) or recurrent VVC (RVVC). Studies were searched in MEDLINE, SCOPUS, and ISI Web of Science until April 2013. Five studies including 704 women (386 cases and 318 controls) were part of the meta-analysis, and pooled ORs were calculated using the random effects model. For subjects with RVVC, ORs of AB versus AA and of BB versus AA were 4.84 (95% CI 2.10–11.15; P for heterogeneity = 0.013; I 2 = 68.6%) and 12.68 (95% CI 3.74–42.92; P for heterogeneity = 0.932, I 2 = 0.0%), respectively. For subjects with VVC, OR of AB versus AA was 2.57 (95% CI 1.29–5.12; P for heterogeneity = 0.897; I 2 = 0.0%). This analysis indicates that heterozygosity for the MBL2 allele B increases significantly the risk for both diseases, suggesting that MBL may influence the women's innate immunity in response to Candida.
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