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 ... -  《-》

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 ... -  《-》

Evaluation of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry for species identification of nonfermenting Gram-negative bacilli.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) to identify 396 Nonfermenting Gram-Negative Bacilli clinical isolates was evaluated in comparison with conventional phenotypic tests and/or molecular methods. MALDI-TOF MS identified to species level 256 isolates and to genus or complex level 112 isolates. It identified 29 genera including uncommon species.

Almuzara M ，Barberis C ，Traglia G ，Famiglietti A ，Ramirez MS ，Vay C ... -  《-》

MALDI-TOF identification of Gram-negative bacteria directly from blood culture bottles containing charcoal: Sepsityper® kits versus centrifugation-filtration method.

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry has dramatically altered the way microbiology laboratories identify clinical isolates. Direct blood culture (BC) detection may be hampered, however, by the presence of charcoal in BC bottles currently in clinical use. This study evaluates an in-house process for extraction and MALDI-TOF identification of Gram-negative bacteria directly from BC bottles containing charcoal. Three hundred BC aliquots were extracted by a centrifugation-filtration method developed in our research laboratory with the first 96 samples processed in parallel using Sepsityper® kits. Controls were colonies from solid media with standard phenotypic and MALDI-TOF identification. The identification of Gram-negative bacteria was successful more often via the in-house method compared to Sepsityper® kits (94.7% versus 78.1%, P≤0.0001). Our in-house centrifugation-filtration method was further validated for isolation and identification of Gram-negative bacteria (95%; n=300) directly from BC bottles containing charcoal.

Riederer K ，Cruz K ，Shemes S ，Szpunar S ，Fishbain JT ... -  《-》