Comparative evaluation of the Vitek-2 Compact and Phoenix systems for rapid identification and antibiotic susceptibility testing directly from blood cultures of Gram-negative and Gram-positive isolates.

We performed a comparative evaluation of the Vitek-2 Compact and Phoenix systems for direct identification and antimicrobial susceptibility testing (AST) from positive blood culture bottles in comparison to the standard methods. Overall, 139 monomicrobial blood cultures, comprising 91 Gram-negative and 48 Gram-positive isolates, were studied. Altogether, 100% and 92.3% of the Gram-negative isolates and 75% and 43.75% of the Gram-positive isolates showed concordant identification between the direct and the standard methods with Vitek and Phoenix, respectively. AST categorical agreements of 98.7% and 99% in Gram-negative and of 96.2% and 99.5% in Gram-positive isolates with Vitek and Phoenix, respectively, were observed. In conclusion, direct inoculation procedures for Gram-negative isolates showed an excellent performance with both automated systems, while for identification of Gram-positive isolates they proved to be less reliable, although Vitek provided acceptable results. This approach contributes to reducing the turnaround time to result of blood cultures, with a positive impact on patient care.

Gherardi G ，Angeletti S ，Panitti M ，Pompilio A ，Di Bonaventura G ，Crea F ，Avola A ，Fico L ，Palazzo C ，Sapia GF ，Visaggio D ，Dicuonzo G ... -  《-》

Rapid identification and susceptibility testing using the VITEK 2 system using culture fluids from positive BacT/ALERT blood cultures.

Chen JR ，Lee SY ，Yang BH ，Lu JJ ... -  《JOURNAL OF MICROBIOLOGY IMMUNOLOGY AND INFECTION》

Identification and susceptibility testing of microorganism by direct inoculation from positive blood culture bottles by combining MALDI-TOF and Vitek-2 Compact is rapid and effective.

The objective of this study was to evaluate the reliability and accuracy of the combined use of MALDI-TOF MS bacterial identification and the Vitek-2 Compact antimicrobial susceptibility testing (AST) directly from positive blood cultures. Direct identification by MALDI-TOF MS and AST were performed in parallel to the standard methods in all positively flagged blood cultures bottles during the study period. Three hundred and twenty four monomicrobial positive blood cultures were included in the present study, with 257 Gram-negative and 67 Gram-positive isolates. MALDI-TOF MS identification directly from blood bottles reported the correct identification for Enterobacteriaceae in 97.7%, non-fermentative Gram-negative bacilli 75.0%, Staphylococcus aureus 75.8%, coagulase negative staphylococci 63.3% and enterococci 63.3%. A total 6156 isolate/antimicrobial agent combinations were tested. Enterobacteriaceae group and non-fermentative Gram-negative Bacilli showed an agreement of 96.67% and 92.30%, respectively, for the Gram-positive cocci the overall agreement found was 97.84%. We conclude that direct identification by MALDI-TOF and inoculation of Vitek-2 Compact AST with positive blood culture bottles yielded very good results and decreased time between initial inoculation of blood culture media and determination of the antibiotic susceptibility for Gram-negative rods and Gram-positive cocci causing bacteremia.

Romero-Gómez MP ，Gómez-Gil R ，Paño-Pardo JR ，Mingorance J ... -  《-》

Evaluation of the Merlin MICRONAUT system for rapid direct susceptibility testing of gram-positive cocci and gram-negative bacilli from positive blood cultures.

Wellinghausen N ，Pietzcker T ，Poppert S ，Belak S ，Fieser N ，Bartel M ，Essig A ... -  《-》

Direct inoculation method using BacT/ALERT 3D and BD Phoenix System allows rapid and accurate identification and susceptibility testing for both Gram-positive cocci and Gram-negative rods in aerobic blood cultures.

This study describes a direct inoculation method using the automated BacT/ALERT 3D and the BD Phoenix System in combination for identification and susceptibility testing of isolates from positive blood cultures. Organism identification and susceptibility results were compared with the conventional method for 211 positive aerobic blood cultures. Of 110 Gram-positive cocci (GPCs), 98 (89.1%) isolates were correctly identified to the species level. Of 101 Gram-negative rods (GNRs), 98 (97.0%) isolates were correctly identified to the species level. The overall categorical agreement in antimicrobial susceptibility testing among the 110 GPCs was 92.7%, with 0.04% very major and 0.7% major error rates. The overall categorical agreement among 78 isolates of enterobacteria and 23 isolates of nonfermenters in GNRs was 99.5% and 91.1%, respectively, with no major errors identified. We conclude that, compared with previously reported direct inoculation methods, our method is superior in identification and susceptibility testing of GPCs.

Yonetani S ，Okazaki M ，Araki K ，Makino H ，Fukugawa Y ，Okuyama T ，Ohnishi H ，Watanabe T ... -  《-》