Publications by authors named "Gema Mendez"

The reliability of Fourier-transform infrared (FT-IR) spectroscopy for typing and outbreak control has been previously assessed, but issues remain in standardization and reproducibility. We developed and validated a reproducible FT-IR with attenuated total reflectance (ATR) workflow for the identification of lineages. We used 293 isolates representing multidrug-resistant lineages causing outbreaks worldwide (2002-2021) to train a random forest classification (RF) model based on capsular (KL)-type discrimination.

View Article and Find Full Text PDF

MALDI-TOF MS is considered to be an important tool for the future development of rapid microbiological techniques. We propose the application of MALDI-TOF MS as a dual technique for the identification of bacteria and the detection of resistance, with no extra hands-on procedures. We have developed a machine learning approach that uses the random forest algorithm for the direct prediction of carbapenemase-producing Klebsiella pneumoniae (CPK) isolates, based on the spectra of complete cells.

View Article and Find Full Text PDF

The Enterobacter cloacae complex (ECC) encompasses heterogeneous clusters of species that have been associated with nosocomial outbreaks. These species may have different acquired antimicrobial resistance and virulence mechanisms, and their identification is challenging. This study aims to develop predictive models based on matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) profiles and machine learning for species-level identification.

View Article and Find Full Text PDF

Mycobacterium abscessus is one of the most common and pathogenic nontuberculous mycobacteria (NTM) isolated in clinical laboratories. It consists of three subspecies: M. abscessus subsp.

View Article and Find Full Text PDF
Article Synopsis
  • Excessive use of piperacillin/tazobactam (P/T) has led to the rise of P/T-resistant bacterial strains, complicating treatment options.
  • To address slow conventional testing methods, researchers developed MALDIpiptaz, a quick and affordable test using MALDI-MS technology to detect P/T resistance in bacterial isolates.
  • Results showed MALDIpiptaz can rapidly differentiate between P/T-resistant, ESRI developer, and P/T-susceptible isolates within 15 minutes, making it a promising tool for clinical diagnostics.
View Article and Find Full Text PDF

Vancomycin-resistant represents a health threat due to its ability to spread and cause outbreaks. MALDI-TOF MS has demonstrated its usefulness for identification, but its implementation for antimicrobial resistance detection is still under evaluation. This study assesses the repeatability of MALDI-TOF MS for peak analysis and its performance in the discrimination of vancomycin-susceptible (VSE) from vancomycin-resistant isolates (VRE).

View Article and Find Full Text PDF

In this study, we evaluate the performance of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid detection of carbapenemase activity in Enterobacterales in clinical microbiology laboratories during a multicenter networking validation study. The study was divided into three different stages: "software design," "intercenter evaluation," and "clinical validation." First, a standardized procedure with an online software for data analysis was designed.

View Article and Find Full Text PDF

Objectives: The main goal of this study was to accurately detect azole resistance in species of the Aspergillus fumigatus complex by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Methods: Identification of isolates (n = 868) was done with MALDI-TOF MS using both commercial and in-house libraries. To determine azole susceptibility, the EUCAST E.

View Article and Find Full Text PDF

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been used for the direct detection of KPC-producing isolates by analysis of the 11,109 Da mass peak representing the P019 protein. In this study, we evaluate the presence of the 11,109 Da mass peak in a collection of 435 unduplicated Klebsiella pneumoniae clinical isolates. The prevalence of the P019 peak in the K.

View Article and Find Full Text PDF

The increasing emergence of carbapenemase-producing Klebsiella pneumoniae (CPK) isolates is a global health alarm. Rapid methods that require minimum sample preparation and rapid data analysis are urgently required. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been used by clinical laboratories for identification of antibiotic-resistant bacteria; however, discrepancies have arisen regarding biological and technical issues.

View Article and Find Full Text PDF

Matrix-assisted laser desorption-ionization/time of flight mass spectrometry (MALDI-TOF MS) has been widely implemented for the rapid identification of microorganisms. Although most bacteria, yeasts and filamentous fungi can be accurately identified with this method, some closely related species still represent a challenge for MALDI-TOF MS. In this study, two MALDI-TOF-based approaches were applied for discrimination at the species-level of isolates belonging to the complex, previously characterized by Amplified Fragment Length Polymorphism (AFLP) and sequencing of the ITS1-5.

View Article and Find Full Text PDF

Objectives: to analyze the long-term immunovirological effect and tolerability of a maraviroc-containing antiretroviral therapy in viraemic and pretreated HIV-infected patients with a high prevalence of hepatitis C virus (HCV) coinfection.

Methods: forty-six R5 HIV-infected patients (48% HCV-coinfected) started a maraviroc-containing antiretroviral regimen, including patients with multidrug resistant virus and patients after first virologic failure. A retrospective study was performed, analysing percentage of patients with undetectable viral load, mean CD4+ gain, liver enzymes, clinical events and treatment modification up to week 48.

View Article and Find Full Text PDF