122 A one-year experience of routine identification by MALDI-TOF MS of non-fermenting Gram-negative rods recovered from respiratory samples from cystic fibrosis patients

Objective: The aim of this study was to determine the capacity of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) to identify 155 HACEK clinical isolates and other fastidious or infrequently isolated Gram-negative rods (e.g., Actinobacillus, Capnocytophaga, Pasteurella, Neisseria, Moraxella, Dysgonomonas, among others). Methods: All the isolates were identified by standard biochemical tests and MALDI-TOF MS. Two different extraction methods (direct transfer formic acid method on spot and ethanol formic acid extraction method) and different cut-offs for genus/specie level identification were used. MALDI-TOF MS identification was considered correct when the result obtained from the MS database agreed with the phenotypic identification result. When both the methods gave discordant results, the 16S rDNA gene sequencing was considered as the gold standard identification method. Results: Employing the score cut-offs suggested by the manufacturer, 93.55% and 69.03% isolates were correctly identified at the genus and species level, respectively. On the contrary , employing lower cut-off scores for identification, 98.06% and 92.09% isolates were properly identified at the genus and species level respectively and no significant differences between the results obtained with two extraction methods were observed . Conclusion: The accurate identification of 14 genera showed the reliability of MALDI-TOF MS as an optional methodology to the routine identification methods currently used in laboratories.

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

Journal of Cystic Fibrosis ◽

10.1016/s1569-1993(16)30332-0 ◽

2016 ◽

Vol 15 ◽

pp. S74-S75

Author(s):

L. O'Brien ◽

G. Edwards ◽

A. Hardy ◽

M. Smith ◽

H. Green ◽

...

Keyword(s):

Cystic Fibrosis ◽

Gram Negative ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tof Ms

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Comparison of Accelerate PhenoTest BC Kit and MALDI-TOF MS/VITEK 2 System for the rapid identification and antimicrobial susceptibility testing of gram-negative bacilli causing bloodstream infections

Official Journal of the Association of Medical Microbiology and Infectious Disease Canada ◽

10.3138/jammi-2020-0004 ◽

2020 ◽

Vol 5 (3) ◽

pp. 145-157

Author(s):

William Stokes ◽

Lorraine Campbell ◽

Johann Pitout ◽

John Conly ◽

Deirdre Church ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Susceptibility Testing ◽

Bloodstream Infections ◽

Rapid Identification ◽

Antimicrobial Susceptibility Testing ◽

Gram Negative ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Vitek 2 ◽

Tof Ms

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Ritkábban előforduló, alsó légúti fertőzést okozó Gram-negatív nem fermentáló pálcák

Orvosi Hetilap ◽

10.1556/650.2018.30926 ◽

2018 ◽

Vol 159 (1) ◽

pp. 23-30

Author(s):

Emese Juhász ◽

Miklós Iván ◽

Júlia Pongrácz ◽

Katalin Kristóf

Keyword(s):

Respiratory Tract ◽

Lower Respiratory Tract ◽

Respiratory Tract Infections ◽

Diffusion Method ◽

Lower Respiratory Tract Infections ◽

Gram Negative ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tract Infections ◽

Tof Ms

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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Evaluation of ID Fungi Plates Medium for Identification of Molds by MALDI Biotyper

Journal of Clinical Microbiology ◽

10.1128/jcm.01687-19 ◽

2020 ◽

Vol 58 (5) ◽

Cited By ~ 2

Author(s):

Marie Gladys Robert ◽

Charlotte Romero ◽

Céline Dard ◽

Cécile Garnaud ◽

Odile Cognet ◽

...

Keyword(s):

Filamentous Fungi ◽

Susceptibility Testing ◽

Antifungal Susceptibility ◽

Antifungal Susceptibility Testing ◽

Maldi Tof Ms ◽

Extraction Protocol ◽

Maldi Tof ◽

Morphological Aspects ◽

Routine Identification ◽

Tof Ms

ABSTRACT MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol.

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