Fast and reliable bacterial identification direct from positive blood culture using a new TFA sample preparation protocol and the Vitek® MS system.

A simple and reliable protocol using 0.1% trifluoroacetic acid (TFA) was developed to identify bacteria directly from blood cultures on the Vitek® MS system. Results presented a correlation of 99% for Gram-negative bacteria at species level, and 86.3% and 82.3% of Gram-positive bacteria at the genus and species levels, respectively.

Monteiro J ，Inoue FM ，Lobo AP ，Sugawara EK ，Boaretti FM ，Tufik S ... -  《-》

Direct common gram-negative bacterial identification from positive blood culture bottles by SELDI-TOF MS.

A protein database was constructed and validated with identification rate over 90% for the 4 most common Gram-negative bacteria on agar plates. By protein masses comparison, 120 bacteria of the 4 species from blood culture bottles were identified. The concordance was high (Kappa=0.906) between our method and conventional approach.

Xiao D ，Yang Y ，Jiang W ，Zhang H ，Liu H ，Yu H ，Xie C ，Zhong M ，Chen L ，Huang W ... -  《-》

Rapid identification of Gram-negative organisms from blood culture bottles using a modified extraction method and MALDI-TOF mass spectrometry.

The application of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry (MS) directly to blood culture broth has potential to identify bloodstream infection earlier and facilitate timely management. We prospectively tested a novel, rapid, and inexpensive in-house spin-lysis protocol with formic acid extraction and compared MALDI-TOF MS identification of Gram-negative bacteria with traditional phenotypic methods (Phoenix™) directly from 318 BACTEC™ (Becton Dickinson, Franklin Lakes, USA) blood cultures. The MS score was ≥1.7 in 268 (91.8%) monomicrobial broths, with concordance to genus and species level of 100% and 97.0%, respectively. MALDI-TOF MS still has limited capacity to detect all species in polymicrobial broths.

Gray TJ ，Thomas L ，Olma T ，Iredell JR ，Chen SC ... -  《-》

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 ... -  《-》

[EXPRESS IDENTIFICATION OF POSITIVE BLOOD CULTURES USING DIRECT MALDI-TOF MASS SPECTROMETRY].

Popov DA ，Ovseenko ST ，Vostrikova TY 《-》