Rapid Discrimination of Pseudomonas aeruginosa ST175 Isolates Involved in a Nosocomial Outbreak Using MALDI-TOF Mass

Ana Candela1,2, Manuel J Arroyo3, María Sánchez-Cueto1,2

  • 1Clinical Microbiology and Infectious Diseases Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain.

Insights

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier-transform infrared spectroscopy (FTIR-S) show promise for detecting Pseudomonas aeruginosa outbreaks. These methods, combined with machine learning, offer rapid identification of high-risk bacterial clones.

Area of Science:

  • Clinical Microbiology
  • Infectious Disease Diagnostics
  • Spectroscopic Analysis

Background:

  • Nosocomial outbreaks caused by *Pseudomonas aeruginosa* pose significant challenges in healthcare settings.
  • Traditional DNA-based methods for bacterial strain typing can be time-consuming and resource-intensive.
  • Rapid and accurate detection of outbreak-specific bacterial clones is crucial for effective infection control.

Purpose of the Study:

  • To evaluate matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier-transform infrared spectroscopy (FTIR-S) as rapid diagnostic alternatives.
  • To assess the utility of these methods for detecting *Pseudomonas aeruginosa* sequence type (ST) 175 isolates during a hospital outbreak.
  • To compare the discriminatory power of MALDI-TOF MS and FTIR-S against established methods like pulse-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS).

Main Methods:

  • Analysis of 27 *P. aeruginosa* isolates from a hospital outbreak using MALDI-TOF MS and FTIR-S.
  • Spectra acquisition involved specific sample preparation protocols for each technique.
  • Data analysis utilized Clover Biosoft Software with machine learning algorithms (e.g., K-nearest neighbor) for classification and validation.

Main Results:

  • MALDI-TOF MS identified three outbreak-specific biomarkers (5,169, 6,915, and 7,236 m/z) with discriminatory power comparable to PFGE.
  • A classification model based on these biomarkers achieved 97.0% correct classification, discriminating clusters similar to WGS.
  • FTIR-S demonstrated discriminatory power similar to PFGE and successfully differentiated the analyzed sequence types (STs).

Conclusions:

  • MALDI-TOF MS and FTIR-S, when combined with machine learning tools, are effective alternatives to DNA-based methods for outbreak detection.
  • These spectroscopic techniques offer a powerful approach for real-time monitoring of high-risk bacterial clones in healthcare environments.
  • The study highlights the potential for rapid, cost-effective identification of pathogens involved in nosocomial infections.

Related Concept Videos

Stereotypes, Prejudice, and Discrimination02:55

Stereotypes, Prejudice, and Discrimination

Humans are very diverse and although we share many similarities, we also have many differences. The social groups we belong to help form our identities (Tajfel, 1974). These differences may be difficult for some people to reconcile, which may lead to prejudice toward people who are different. Prejudice is a negative attitude and feeling toward an individual based solely on one’s membership in a particular social group (Allport, 1954; Brown, 2010). Prejudice is common against people who...
89.6K
Confirmation Biases01:31

Confirmation Biases

The confirmation bias is the tendency to focus on information that confirms our existing beliefs and ignore information that is inconsistent with our expectations. For example, if you think that your professor is not very nice, you notice all of the instances of rude behavior exhibited by the professor while ignoring the countless pleasant interactions he is involved in on a daily basis. Have you ever fallen prey to the confirmation bias, either as the source or target of such bias?
5.4K
Generalization, Discrimination, and Extinction01:24

Generalization, Discrimination, and Extinction

Generalization, discrimination, and extinction are key concepts in operant conditioning that influence how behaviors are learned and maintained.
Generalization occurs when a behavior reinforced in one context is performed in similar situations. For instance, a student who studies diligently for calculus and receives excellent grades might apply the same study habits to psychology and history, expecting similar results. Generalization shows how learning in one setting can influence behavior in...
334
Diversity in Cell Signaling Responses01:22

Diversity in Cell Signaling Responses

The physiological function of a cell and cellular communication are outcomes of a range of extrinsic signals, intracellular signaling pathways, and cellular responses. No two cell types express the same repertoire of signaling components. Receptors are highly selective for their cognate ligands, but once activated, they can alter multiple cellular processes such as DNA transcription, protein synthesis, and metabolic activity. 
Graded and Abrupt Responses
Some signaling systems generate...
6.3K
High-Performance Liquid Chromatography: Types of Detectors01:15

High-Performance Liquid Chromatography: Types of Detectors

The role of the detectors in High-Performance Liquid Chromatography (HPLC) is to analyze the solutes as they exit from the chromatographic column. The detector recognizes the solute's property and generates corresponding electrical signals, which are converted into a readable graph of the detector's response versus elution time called a chromatogram at the computer. There are several types of HPLC detectors, each with its own advantages and limitations, depending on the analyte...
357
Stereotype Threat and Self-fulfilling Prophecies02:09

Stereotype Threat and Self-fulfilling Prophecies

When we hold a stereotype about a person, we have expectations that he or she will fulfill that stereotype. A self-fulfilling prophecy is an expectation held by a person that alters his or her behavior in a way that tends to make it true. When we hold stereotypes about a person, we tend to treat the person according to our expectations. This treatment can influence the person to act according to our stereotypic expectations, thus confirming our stereotypic beliefs. Research by Rosenthal and...
37.2K