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Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment.

BACKGROUND: Septic thrombophlebitis increases patient morbidity and mortality following metastatic infections, pulmonary emboli, and/or septic shock. Central venous catheter (CVC) removal for occult septic thrombophlebitis challenges current strategy in neutropenic patients. PATIENTS AND METHODS: We prospectively evaluated infection-related mortality in 100 acute leukemia patients, with CVC-related bloodstream infection (CRBSI) after chemotherapy, who systematically underwent ultrasonography to identify the need for catheter removal. Their infection-related mortality was compared with that of a historical cohort of 100 acute leukemia patients, with CRBSI after chemotherapy, managed with a clinically driven strategy. Appropriate antimicrobial therapy was administered in all patients analyzed. RESULTS: In the prospective series, 30/100 patients required catheter removal for ultrasonography-detected septic thrombophlebitis after 1 median day from BSI onset; 70/100 patients without septic thrombophlebitis retained their CVC. In the historical cohort, 60/100 patients removed the catheter (persistent fever, 40 patients; persistent BSI, 10 patients; or clinically manifest septic thrombophlebitis, 10 patients) after 8 median days from BSI onset; 40/100 patients retained the CVC because they had not clinical findings of complicated infection. At 30 days median follow-up, one patient died for infection in the ultrasonography-assisted group versus 17 patients in the historical cohort (P < 0.01). With the ultrasonography-driven strategy, early septic thrombophlebitis detection and prompt CVC removal decrease infection-related mortality, whereas clinically driven strategy leads to inappropriate number, reasons, and timeliness of CVC removal. CONCLUSION: Ultrasonography is an easy imaging diagnostic tool enabling effective and safe management of patients with acute leukemia and CRBSI.

In total, 124 Streptococcus pyogenes isolates were obtained from throat cultures of different symptomatic patients. All isolates showed M-pheno-type macrolide resistance and contained the macrolide efflux gene mef (A). The isolates were screened for the presence and insertion site of mef (A)-containing genetic elements. In 25.8% of the isolates, mef (A) was found to be carried by elements belonging to the Tn 1207.3 /Φ10394.4 family inserted in the comEC gene, while 74.2% contained chimeric elements with a different genetic structure and chromosomal location, probably associated with the recently described 60-kb tet (O)– mef (A) element.