MALDI-TOF MS Identification and Clustering Applied to Species in Nosocomial Setting.

microorganisms cause important bacterial infections in humans. Recently, carbapenem resistant isolates carrying the KPC gene were described and their clonal transmission in different nosocomial outbreaks reported. In this study, the relative numbers of species, their antimicrobial susceptibility along 3 years of observation and the identification ability of the two most common MALDI-TOF platforms were evaluated.

Multi-drug resistant Pseudomonas aeruginosa nosocomial strains: Molecular epidemiology and evolution.

Pseudomonas aeruginosa causes a wide variety of nosocomial infections. In the study, phylogenetic, selective pressure analysis and homology modelling were applied to oprD efflux pump gene with the aim to characterize multi-drug resistant strains circulating in the nosocomial setting, their transmission dynamics and ongoing evolution. One hundred ninety-three consecutive inpatients with Pseudomonas aeruginosa infection were enrolled at the University Campus Bio-Medico of Rome, between January 2015 and December 2016.

Klebsiella pneumoniae blaKPC-3 nosocomial epidemic: Bayesian and evolutionary analysis.

K. pneumoniae isolates carrying blaKPC-3 gene were collected to perform Bayesian phylogenetic and selective pressure analysis and to apply homology modeling to the KPC-3 protein. A dataset of 44 bla-3 gene sequences from clinical isolates of K.

Unusual microorganisms and antimicrobial resistances in a group of Syrian migrants: Sentinel surveillance data from an asylum seekers centre in Italy.

Background: Three years of civil war in Syria have caused death and increase of communicable diseases. The suffering population has been forced to migrate creating a fertile condition for epidemic spread of infection within the refugee camps.

Methods: Forty-eight Syrian migrants, upon their arrival in Italy, were accommodated at the asylum seekers centre of Castelnuovo di Porto.

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and Bayesian phylogenetic analysis to characterize Candida clinical isolates.

Clinical Candida isolates from two different hospitals in Rome were identified and clustered by MALDI-TOF MS system and their origin and evolution estimated by Bayesian phylogenetic analysis. The different species of Candida were correctly identified and clustered separately, confirming the ability of these techniques to discriminate between different Candida species. Focusing MALDI-TOF analysis on a single Candida species, Candida albicans and Candida parapsilosis strains clustered differently for hospital setting as well as for period of isolation than Candida glabrata and Candida tropicalis isolates.

Turnaround time of positive blood cultures after the introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry.

A comparative evaluation of the turnaround time (TAT) of positive blood culture before and after matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) introduction in the laboratory routine was performed. A total of 643 positive blood cultures, of which 310 before and 333 after MALDI-TOF technique introduction, were collected. In the post MALDI-TOF period, blood culture median TAT decreased from 73.

Viridans Group Streptococci clinical isolates: MALDI-TOF mass spectrometry versus gene sequence-based identification.

Viridans Group Streptococci (VGS) species-level identification is fundamental for patients management. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been used for VGS identification but discrimination within the Mitis group resulted difficult. In this study, VGS identifications with two MALDI-TOF instruments, the Biotyper (Bruker) and the VITEK MS (bioMérieux) have been compared to those derived from tuf, soda and rpoB genes sequencing.