scholarly journals 536. Challenges in Using MALDI-TOF Technology to Assess for KPC Resistance in Klebsiella pneumoniae isolates in America

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S256-S257
Author(s):  
Michael Christopher Thompson ◽  
David Banach ◽  
Christina Nishimura ◽  
Anthony Muyombwe
Keyword(s):  
Klebsiella Pneumoniae ◽  
Protein Extraction ◽  
High Sensitivity ◽  
Rapid Identification ◽  
Health Concern ◽  
Ionization Time ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Maldi Tof ◽  
Control And Prevention ◽  
Low Sensitivity

Abstract Background The emergence of Klebsiella pneumoniae Carbapenemase-producing Enterobacteriaceae (KPC-E) has created a major public health concern. In clinical practice, rapid identification of KPC-KP has important implications for clinical management and infection control. In some settings matrix-assisted laser desorption ionization time of flight (MALDI-TOF) software has been used for rapid detection of KPC producing K. pneumoniae with high sensitivity and specificity. Genomic sequencing has determined that the 11.09 m/z peak is related to protein expression from the P109 gene found mostly in Tna4401a isoform among KPC-E. In our study, we evaluated the use of MALDI-TOF automated detection software to evaluate for KPC detection among a diverse group of KPC-E isolates. Methods We tested 52 KPC-E isolates from various hospitals in Connecticut and the Centers for Disease Control and Prevention (CDC) Antibiotic Resistance (AR) Bank. All specimens were verified as KPC-producing strains by detection of the blaKPCgene through polymerase chain reaction. Protein extraction using the standard extraction method was performed on sub-cultured isolates. Each isolate was tested three times on MALDI-TOF MS with the incorporated bio-subtype KPC module. An organism confidence or log score value of 2 or higher was considered valid. Results Among 52 tested KPC-K. pneumoniae isolates, 44 (85%) were from various hospitals in Connecticut, eight (15%) came from the AR Bank. Only 15 (25.1%) of the isolates were detected as KPC-producing using the MALDI-TOF KPC module. Further investigation by peak analysis confirmed all 15 isolates detected positive demonstrated a peak at 11.09 m/z. The 11.09 m/z peak was not found in the 37 specimens that were not detected. Conclusion The results from our study suggest low sensitivity using this software and contradicts results seen in previous European studies. The Tna4401a isoform is often seen in KPC-2 strains, which may be less prevalent in our sample of isolates, explaining the poor sensitivity of MALDI-TOF. Further study is needed to explore this finding and potential opportunities for MALDI-TOF for rapid identification of KPC-KP. Disclosures All authors: No reported disclosures.

scholarly journals 12. Evaluation of Rapid Phenotypic Testing for KPC Carbapenemase Producing klebsiella Pneumoniae Directly from Positive Blood Cultures by Use of “Hot Chocolate” Plates

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S7-S7
Author(s):  
Alexander Lawandi ◽  
Gleice C Leite ◽  
Brigitte Lefebvre ◽  
Jean Longtin ◽  
Todd C Lee
Keyword(s):  
Klebsiella Pneumoniae ◽  
Carbapenem Resistance ◽  
Empiric Therapy ◽  
Turnaround Time ◽  
Rapid Identification ◽  
Blood Cultures ◽  
Minimal Growth ◽  
Maldi Tof ◽  
Considerable Morbidity ◽  
Hot Chocolate

Abstract Background Invasive infections with Carbapenemase Producing Enterobacterales are associated with considerable morbidity and mortality, in part due to the risk of inappropriate empiric therapy. Consequently, the rapid identification of carbapenem resistance is crucial to the management of these infections. We sought to evaluate possible reductions in turnaround time to identification of this resistance in blood cultures growing these organisms by applying rapid phenotypic test kits to growth from “hot chocolate” plates. Methods 30 blood cultures, spiked with carbapenem resistant Klebsiella pneumoniae isolates or susceptible controls, were inoculated onto chocolate agars that had pre-warmed at 37°C. These plates were incubated at 37ºC for 3.5 hours. The resulting minimal growth was then identified using MALDI-TOF and underwent rapid phenotypic testing using three commercially available products (β-lacta and β-carba, from Bio-Rad, Marnes-la-Coquette, France, and Carba-NP, from bioMérieux, Durham, NC). The time to identification of carbapenem resistance using this method was then compared to that of the conventional laboratory workup. Results The identification was 100% accurate to the species level using MALDI-TOF paired to the 3.5 hour growth on the “hot choocolate” plates. The β-lacta kit identified resistance to 3rd generation cephalosporins for all ESBL and carbapenemase producing Klebsiella pneumoniae isolates, while the β-carba and Carba-NP kits identified carbapenem resistance only in the carbapenemase producers. The sensitivity of all assays was 100% (95% CI 0.87–1.0) and the specificity of carbapenemase detection was 100% (97.5% one-sided CI 0.4–1.0). The corresponding sensitivities and specificities of direct disc diffusion for ertapenem resistance detection were 88.5% (95% CI 0.70–0.98) and 100% (95%CI 0.40–1.0) respectively. The turnaround time for the rapid kits coupled to the “hot chocolate” plates was 4.25 to 5.1 hours as compared to 16 hours for the conventional workup. Conclusion Rapid phenotypic tests performed after inoculation of “hot chocolate” plates are highly sensitive for the presence of carbapenemase production and can be incorporated into the laboratory workflow for Klebisella pneumoniae with important reductions in turnaround time. Disclosures All Authors: No reported disclosures

scholarly journals Evaluation of HiCrome KPC Agar for the Screening of Carbapenem-Resistant Enterobacterales Colonization in the ICU Setting of a Tertiary Care Hospital

2021 ◽  
Author(s):  
Ashoka Mahapatra ◽  
K Nikitha ◽  
Sutapa Rath ◽  
Bijayini Behera ◽  
Kavita Gupta
Keyword(s):  
Tertiary Care ◽  
High Sensitivity ◽  
Care Hospital ◽  
Predictive Values ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Carbapenem Resistant ◽  
Rectal Swabs ◽  
Control And Prevention ◽  
Indian Setting ◽  
Sensitivity Specificity

Abstract Background Spread of carbapenem-resistant Enterobacterales (CRE) is a significant concern in intensive care unit (ICU) settings. Approaches to routine screening for CRE colonization in all ICU patients vary depending on institutional epidemiology and resources. The present study was aimed to evaluate the performance of HiCrome Klebsiella pneumoniae carbapenemase (KPC) agar for the detection of CRE colonization in ICU settings taking the Centers for Disease Control and Prevention (CDC) recommended method as reference. Methods Two-hundred and eighty rectal swabs (duplicate) from 140 patients were subjected to CRE detection in HiCrome KPC agar and MacConkey agar (CDC criteria). Results Using CDC method, total 41 CRE isolates were recovered comprising of 29 E scherichia coli, 11 Klebsiella, and 1 Enterobacter spp. On the other hand, 49 isolates of CRE recovered from 140 rectal swabs using HiCrome KPC agar, out of which 33 were E. coli, 15 Klebsiella, and 1 Enterobacter sp. Statistical Analysis Sensitivity, specificity, negative, and positive predictive values of CRE screening by HiCrome KPC agar were found to be 100% (91.4–100), 91.9% (84.8–95.8), 83.6% (70.9–91.4), and 100% (95.9–100), respectively, taking the CDC recommended method as reference. Conclusion HiCrome KPC agar has high sensitivity in screening CRE colonization. Further studies are needed to establish its applicability for detecting the predominant circulating carbapenemases in the Indian setting.

scholarly journals Establishment and Application of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Detection of Shewanella Genus

2021 ◽  
Vol 12 ◽  
Author(s):  
Keyi Yu ◽  
Zhenzhou Huang ◽  
Ying Li ◽  
Qingbo Fu ◽  
Lirong Lin ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Rapid Identification ◽  
Species Level ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Type Strains ◽  
Tof Ms

Shewanella species are widely distributed in the aquatic environment and aquatic organisms. They are opportunistic human pathogens with increasing clinical infections reported in recent years. However, there is a lack of a rapid and accurate method to identify Shewanella species. We evaluated here matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid identification of Shewanella. A peptide mass reference spectra (PMRS) database was constructed for the type strains of 36 Shewanella species. The main spectrum projection (MSP) cluster dendrogram showed that the type strains of Shewanella species can be effectively distinguished according to the different MS fingerprinting. The PMRS database was validated using 125 Shewanella test strains isolated from various sources and periods; 92.8% (n = 116) of the strains were correctly identified at the species level, compared with the results of multilocus sequence analysis (MLSA), which was previously shown to be a method for identifying Shewanella at the species level. The misidentified strains (n = 9) by MALDI-TOF MS involved five species of two groups, i.e., Shewanella algae–Shewanella chilikensis–Shewanella indica and Shewanella seohaensis–Shewanella xiamenensis. We then identified and defined species-specific biomarker peaks of the 36 species using the type strains and validated these selected biomarkers using 125 test strains. Our study demonstrated that MALDI-TOF MS was a reliable and powerful tool for the rapid identification of Shewanella strains at the species level.

scholarly journals Evaluation of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Rapid Identification of Bacteria in Processed Soybean Products

2013 ◽  
Vol 2 (3) ◽  
pp. 104 ◽  
Author(s):  
Yuko Furukawa ◽  
Mitsuru Katase ◽  
Kazunobu Tsumura
Keyword(s):  
Laser Desorption ◽  
Rapid Identification ◽  
Bacterial Cells ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Identification Of Bacteria ◽  
Tof Ms

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently been demonstrated as a rapid and reliable method for identifying bacteria in colonies grown on culture plates. Rapid identification of food spoilage bacteria is important for ensuring the quality and safety of food. To shorten the time of analysis, several researchers have proposed the direct MALDI-TOF MS tequnics for identification of bacteria in clinical samples such as urine and positive blood cultures. In this study, processed soybean products (total 26 test samples) were initially conducted a culture enrichiment step and bacterial cells were separated from interfering components. Harvested bacterial cells were determined by MALDI-TOF MS and 16S rRNA gene sequencing method. Six processed soybean products (23%) were increased bacterial cells after culture enrichiment step and they were sucessfully obtained the accurate identification results by MALDI-TOF MS-based method without colony formation.

Multiplex ALK, RET, and ROS1 fusion mutation detection in FFPE from lung cancer patients by MALDI-TOF mass spectrometry.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e13103-e13103
Author(s):  
Kang-Yi Su ◽  
Bing-Ching Ho ◽  
Gee-Chen Chang ◽  
Hsuan-Yu Chen ◽  
Pan-Chyr Yang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Lung Cancer ◽  
High Sensitivity ◽  
Poor Quality ◽  
Lung Cancer Patients ◽  
Maldi Tof Mass Spectrometry ◽  
Anaplastic Lymphoma ◽  
Maldi Tof ◽  
Low Sensitivity ◽  
Alk 5

e13103 Background: Approximately 3-7% of lung tumors harbor anaplastic lymphoma kinase (ALK) fusions in the subgroup of non-small cell lung cancer (NSCLC). In addition to echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion, TRK-fused gene (TFG)-ALK, kinesin family member 5B (KIF5B)-ALK and kinesin light chain 1 (KLC1)-ALK had been reported in lung cancer. On the other hand, RET proto-oncogene (RET) and ROS proto-oncogene 1 (ROS1) fusion proteins also have prevalence in lung cancer. Food and Drug Administration (FDA)-approved several target drugs are available to treat patients with fusion mutations. Therefore, the diagnosis of ALK, RET or ROS1 fusion genes shows quite important. However, nowadays methods of detecting fusions such as fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are limited to technique, low sensitivity, sample quality as well as subtype classification. Methods: We established nucleotide MALDI-TOF mass spectrometry based multiplex detection platform to distinguish major types including 9 types of EML4-ALK, 5 types of ALK, 5 types of RET and 8 types ROS1 fusions. Results: The detection limitation was about less 1% mutant cells among wild-type cells. In the pilot testing, we used 2 patients’ cell cDNA and 4 patients’ lung FFPE samples cDNA, which had been diagnosed as ALK fusion before, to be detected by this panel, and then identified their variant types successfully. Furthermore, one patient harbored CCDC6-RET fusion mutation was identified by our platform and confirmed by Sanger Sequencing. Conclusions: Taken together, this new panel has high sensitivity and allows little and poor quality samples for detecting. The correlation between clinical characteristics and fusion subtypes can be further investigated by utilizing this platform in the future. Also, the detection panel can be revised based on clinical needs by removing/adding probes.

scholarly journals MDRSA: A Web Based-Tool for Rapid Identification of Multidrug Resistant Staphylococcus aureus Based on Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

2021 ◽  
Vol 12 ◽  
Author(s):  
Chia-Ru Chung ◽  
Zhuo Wang ◽  
Jing-Mei Weng ◽  
Hsin-Yao Wang ◽  
Li-Ching Wu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Rapid Identification ◽  
Antibiotics Resistance ◽  
Web Tool ◽  
Web Based ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

As antibiotics resistance on superbugs has risen, more and more studies have focused on developing rapid antibiotics susceptibility tests (AST). Meanwhile, identification of multiple antibiotics resistance on Staphylococcus aureus provides instant information which can assist clinicians in administrating the appropriate prescriptions. In recent years, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful tool in clinical microbiology laboratories for the rapid identification of bacterial species. Yet, lack of study devoted on providing efficient methods to deal with the MS shifting problem, not to mention to providing tools incorporating the MALDI-TOF MS for the clinical use which deliver the instant administration of antibiotics to the clinicians. In this study, we developed a web tool, MDRSA, for the rapid identification of oxacillin-, clindamycin-, and erythromycin-resistant Staphylococcus aureus. Specifically, the kernel density estimation (KDE) was adopted to deal with the peak shifting problem, which is critical to analyze mass spectra data, and machine learning methods, including decision trees, random forests, and support vector machines, which were used to construct the classifiers to identify the antibiotic resistance. The areas under the receiver operating the characteristic curve attained 0.8 on the internal (10-fold cross validation) and external (independent testing) validation. The promising results can provide more confidence to apply these prediction models in the real world. Briefly, this study provides a web-based tool to provide rapid predictions for the resistance of antibiotics on Staphylococcus aureus based on the MALDI-TOF MS data. The web tool is available at: http://fdblab.csie.ncu.edu.tw/mdrsa/.

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