title: Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry: rapid identification of bacteria isolated from patients with cystic fibrosis.
abstract: Despite extensive research into the diagnosis and management of cystic fibrosis (CF) over the past decades, sufferers still have a median life expectancy of less than 37 years. Respiratory tract infections have a significant role in increasing the morbidity and mortality of patients with CF via a progressive decline in lung function. Rapid identification of organisms recovered from CF sputum is necessary for effective management of respiratory tract infections; however, standard techniques of identification are slow, technically demanding and expensive. The aim of this study is to asses the suitability of matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF MS) in identifying bacteria isolated from the respiratory tract of patients with CF, and is assessed by testing the accuracy of MALDI-TOF MS in identifying samples from a reference collection of rare CF strains in conjunction with comparing MALDI-TOF MS and standard techniques in identifying clinical isolates from sputum samples of CF patients. MALDI-TOF MS accurately identified 100% of isolates from the reference collection of rare CF pathogens (EuroCare CF collection). The isolate identification given by MALDI-TOF MS agreed with that given by standard techniques for 479/481 (99.6%) clinical isolates obtained from respiratory samples provided by patients with CE In two (0.4%) of 481 samples there was a discrepancy in identification between MALDI-TOF MS and standard techniques. One organism was identified as Pseudomonas aeruginosa by MALDI-TOF but could only be identified by the laboratory's standard methods as of the Pseudomonas genus. The second organism was identified as P. beteli by MALDI-TOF MS and Stenotrophomonas maltophilia by standard methods. This study shows that MALDI-TOF MS is superior to standard techniques in providing cheap, rapid and accurate identification of CF sputum isolates.
authors.affiliation: Centre for Immunology and Infectious Diseases, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Baillie
authors.affiliation: Centre for Immunology and Infectious Diseases, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Ireland
authors.affiliation: Department of Microbiology, Barts Health NHS trust, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Warwick
authors.affiliation: Centre for Immunology and Infectious Diseases, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Wareham
authors.affiliation: Centre for Immunology and Infectious Diseases, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Wilks
mesh_terms: D015373:Bacterial Typing Techniques; D003550:Cystic Fibrosis / Q000382:microbiology*; D006801:Humans; D010641:Phenotype; D011237:Predictive Value of Tests; D011552:Pseudomonas Infections / Q000175:diagnosis; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000302:isolation & purification; D015203:Reproducibility of Results; D012141:Respiratory Tract Infections / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013183:Sputum / Q000382:microbiology; D013997:Time Factors