93 The use of MALDI-TOF MS for the identification of non-fermenting Gram-negative bacilli isolated from cystic fibrosis patients

Abstract: Introduction: Glucose non-fermenting Gram-negative bacteria are ubiquitous environmental organisms. Most of them are identified as opportunistic, nosocomial pathogens in patients. Uncommon species are identified accurately, mainly due to the introduction of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology practice. Most of these uncommon non-fermenting rods are isolated from lower respiratory tract samples. Their significance in lower respiratory tract infections, such as rules of their testing are not clarified yet. Aim: The aim of this study was to review the clinical microbiological features of these bacteria, especially their roles in lower respiratory tract infections and antibiotic treatment options. Method: Lower respiratory tract samples of 3589 patients collected in a four-year period (2013–2016) were analyzed retrospectively at Semmelweis University (Budapest, Hungary). Identification of bacteria was performed by MALDI-TOF MS, the antibiotic susceptibility was tested by disk diffusion method. Results: Stenotrophomonas maltophilia was revealed to be the second, whereas Acinetobacter baumannii the third most common non-fermenting rod in lower respiratory tract samples, behind the most common Pseudomonas aeruginosa. The total number of uncommon non-fermenting Gram-negative isolates was 742. Twenty-three percent of isolates were Achromobacter xylosoxidans. Beside Chryseobacterium, Rhizobium, Delftia, Elizabethkingia, Ralstonia and Ochrobactrum species, and few other uncommon species were identified among our isolates. The accurate identification of this species is obligatory, while most of them show intrinsic resistance to aminoglycosides. Resistance to ceftazidime, cefepime, piperacillin-tazobactam and carbapenems was frequently observed also. Conclusions: Ciprofloxacin, levofloxacin and trimethoprim-sulfamethoxazole were found to be the most effective antibiotic agents. Orv Hetil. 2018; 159(1): 23–30.

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108 First identification of non-lactose fermenting Gram negative respiratory isolates from an Irish cystic fibrosis population using matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS)

Journal of Cystic Fibrosis ◽

10.1016/s1569-1993(12)60278-1 ◽

2012 ◽

Vol 11 ◽

pp. S84 ◽

Cited By ~ 1

Author(s):

A.-R. Prior ◽

D. Keating ◽

R. Sheehan ◽

A. Salmon ◽

D. Britton ◽

...

Keyword(s):

Mass Spectrometry ◽

Cystic Fibrosis ◽

Laser Desorption ◽

Gram Negative ◽

Maldi Tof Ms ◽

Flight Mass Spectrometry ◽

Cystic Fibrosis Population ◽

Tof Ms ◽

Matrix Assisted Laser ◽

Matrix Assisted Laser Desorption

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A Prospective Evaluation of Two Rapid Phenotypical Antimicrobial Susceptibility Technologies for the Diagnostic Stewardship of Sepsis

BioMed Research International ◽

10.1155/2018/6976923 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 15

Author(s):

Cesira Giordano ◽

Elena Piccoli ◽

Veronica Brucculeri ◽

Simona Barnini

Keyword(s):

Antimicrobial Susceptibility ◽

Multidrug Resistant ◽

Rapid Identification ◽

Blood Cultures ◽

Gram Positive ◽

Gram Negative ◽

Maldi Tof Ms ◽

Gram Positive Bacteria ◽

Maldi Tof ◽

Tof Ms

Rapid identification of bloodstream pathogens by MALDI-TOF MS and the recently introduced rapid antimicrobial susceptibility testing (rAST) directly from positive blood cultures allow clinicians to promptly achieve a targeted therapy, especially for multidrug resistant microorganisms. In the present study, we propose a comparison between phenotypical rASTs performed in light-scattering technology (Alfred 60AST, Alifax®) and fluorescencein situhybridization (Pheno™, Accelerate) directly from positive blood cultures, providing results in 4–7 hours. Blood samples from 67 patients admitted to the Azienda Ospedaliero-Universitaria Pisana were analyzed. After the direct MALDI-TOF MS identification, the rAST was performed at the same time both on Alfred 60AST and Pheno. Alfred 60AST provided qualitative results, interpreted in terms of clinical categories (SIR). Pheno provided identification and MIC values for each antibiotic tested. Results were compared to the broth microdilution assay (SensiTitre™, Thermo Fisher Scientific), according to EUCAST rules. Using Alfred 60AST, an agreement was reached, 91.1% for Gram-negative and 95.7% for Gram-positive bacteria, while using Pheno, the agreement was 90.6% for Gram-negative and 100% for Gram-positive bacteria. Both methods provided reliable results; Alfred 60AST combined with MALDI-TOF MS proved itself faster and cheaper. Pheno provided identification and MIC determination in a single test and, although more expensive, may be useful whenever MIC value is necessary and where MALDI-TOF MS is not present.

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Optimizing identification of common respiratory pathogens from cystic fibrosis patients using MALDI-TOF MS method

Qatar Foundation Annual Research Forum Proceedings ◽

10.5339/qfarf.2013.biop-0162 ◽

2013 ◽

pp. BIOP 0162

Author(s):

Atqah Abdulwahab

Keyword(s):

Cystic Fibrosis ◽

Respiratory Pathogens ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tof Ms

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Rapid detection by MALDI-TOF MS of isolates from cystic fibrosis patients belonging to the epidemic clones Achromobacter xylosoxidans ST137 or Achromobacter ruhlandii DES.

Journal of Clinical Microbiology ◽

10.1128/jcm.00946-21 ◽

2021 ◽

Author(s):

Thomas Garrigos ◽

Manon Dollat ◽

Arnaud Magallon ◽

Angélique Chapuis ◽

Véronique Varin ◽

...

Keyword(s):

Cystic Fibrosis ◽

Achromobacter Xylosoxidans ◽

Ionization Time ◽

Maldi Tof Ms ◽

Local Database ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Maldi Biotyper ◽

Bruker Daltonics ◽

Tof Ms

Objective: Achromobacter spp. are increasingly reported among cystic fibrosis patients. Genotyping requires time consuming methods such as Multilocus-Sequence-Typing or Pulsed-Field-Gel-Electrophoresis. Therefore, data on the prevalence of the multiresistant epidemic clones, especially A. xylosoxidans ST137 (AxST137) and the Danish Epidemic Strain A. ruhlandii (DES) are lacking. We recently developed and published a database for Achromobacter species identification by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS, Bruker Daltonics). The aim of this study was to evaluate the ability of the MALDI-TOF MS to distinguish these multiresistant epidemic clones within Achromobacter species. Methods: All the spectra of A.xylosoxidans (n=1571) and A.ruhlandii (n=174) used to build the local database were analysed by ClinProTools™, MALDI Biotyper® PCA, MALDI Biotyper ® dendrogram and flexAnalysis™ softwares for biomarker peaks detection. Two-hundred-two isolates (including 48 isolates of AxST137 and 7 of DES) were tested. Results: Specific biomarker peaks were identified: absent peak at m/z 6651 for AxST137 isolates and present peak at m/z 9438 for DES isolates. All tested isolates were well typed by our local database and clustered within distinct groups (ST137 or non-ST137 and DES or non-DES) no matter the MALDI-TOF software or only by simple visual inspection of the spectra by any user. Conclusions: The use of MALDI-TOF MS allowed identifying isolates of A. xylosoxidans belonging to the AxST137 clone which spread in France and Belgium (the Belgian epidemic clone) and of A. ruhlandii belonging to the DES clone. This tool will help implementation of segregation measures to avoid inter-patient transmission of these resistant clones.

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