Compliance of clinical microbiology laboratories with recommendations for the diagnosis of bloodstream infections: Data from a nationwide survey in Italy.

In 2014, the Italian Working Group for Infections in Critically Ill Patient of the Italian Association of Clinical Microbiologists updated the recommendations for the diagnostic workflow for bloodstream infections (BSI). Two years after publication, a nationwide survey was conducted to assess the compliance with the updated recommendations by clinical microbiology laboratories. A total of 168 microbiologists from 168 laboratories, serving 204 acute care hospitals and postacute care facilities, were interviewed during the period January-October 2016 using a questionnaire consisting of nineteen questions which assessed the level of adherence to various recommendations. The most critical issues were as follows: (a) The number of sets of blood cultures (BC) per 1,000 hospitalization days was acceptable in only 11% of laboratories; (b) the minority of laboratories (42%) was able to monitor whether BCs were over or under-inoculated; (c) among the laboratories monitoring BC contamination (80%), the rate of contaminated samples was acceptable in only 12% of cases;(d) the Gram-staining results were reported within 1 hr since BC positivity in less than 50% of laboratories. By contrast, most laboratories received vials within 2-4 hr from withdrawal (65%) and incubated vials as soon as they were received in the laboratory (95%). The study revealed that compliance with the recommendations is still partial. Further surveys will be needed to monitor the situation in the future.

Early diagnosis of invasive pulmonary aspergillosis in a young immunocompetent patient.

A 22-year-old insulin-dependent diabetic male was admitted for diabetic ketoacidosis. He developed hospital-acquired pneumonia (HAP) for which empirical antibiotic and antifungal therapy was started on the ward. On day 6, clinical and laboratory findings worsened, and bronchoalveolar lavage (BAL) was performed. Serum real time-polymerase chain reaction (RT-PCR) indicated invasive pulmonary aspergillosis (IPA) and led to antifungal therapy being initiated 48 hours before the results of the BAL culture were available. Despite early appropriate antifungal therapy, however, the patient died on day 22 while being supported by venovenous extracorporeal membrane oxygenation.

Direct identification of bacteria in blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a new methodological approach.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently been demonstrated to be a powerful tool for the rapid identification of bacteria from growing colonies. In order to speed up the identification of bacteria, several authors have evaluated the usefulness of this MALDI-TOF MS technology for the direct and quick identification bacteria from positive blood cultures. The results obtained so far have been encouraging but have also shown some limitations, mainly related to the bacterial growth and to the presence of interference substances belonging to the blood cultures. In this paper, we present a new methodological approach that we have developed to overcome these limitations, based mainly on an enrichment of the sample into a growing medium before the extraction process, prior to mass spectrometric analysis. The proposed method shows important advantages for the identification of bacterial strains, yielding an increased identification score, which gives higher confidence in the results.

In vitro fluconazole susceptibility of 1565 clinical isolates of Candida species evaluated by the disk diffusion method performed using NCCLS M44-A guidelines.

We determined the in vitro activity of fluconazole against 1565 clinical Candida spp. isolates collected from different specimens of non-AIDS outpatients and inpatients in 3 different regions of Italy. Susceptibility testing was performed by agar disk diffusion using the NCCLS document M44-A guidelines. Candida albicans was the most frequently isolated yeast (68%) followed by C. glabrata (15%), C. tropicalis (5%), C. parapsilosis (5%), and C. krusei (5%). Other yeasts represented 4% of all isolates. Of the 1565 isolates tested, 1449 (92.6%) were susceptible (S) to fluconazole, 43 (2.7%) were susceptible dose-dependent (S-DD) and 73 (4.7%) were resistant (R). Almost all (98.2%) of the C. albicans isolates were classified as S or S-DD. Despite its widespread use, fluconazole displayed good activity against the isolates we tested, and the disk diffusion method was confirmed as a reliable approach to the evaluation of in vitro susceptibility of yeasts to this antimycotic agent.