Molecular Characterization of Vancomycin-Resistant Enterococcus spp. from Clinical Samples and Identification of a

Raúl Alejandro Atriano Briano1, Nallely S Badillo-Larios2, Perla Niño-Moreno2,3

  • 1Laboratory of Hematology, Faculty of Chemical Sciences, Autonomous University of San Luis Potosi, San Luis Potosi 78240, Mexico.

Insights

This study reveals that common hospital-acquired infection bacteria, Enterococcus, possess virulence factors and resistance genes. The emerging ST2700 strain shows high virulence and drug resistance, requiring urgent monitoring.

Area of Science:

  • Microbiology and Infectious Diseases
  • Molecular Biology and Genetics
  • Antimicrobial Resistance Research

Background:

  • Enterococcus species are a leading cause of healthcare-associated infections, driven by virulence factors and increasing vancomycin resistance.
  • The interplay between antimicrobial resistance and virulence in Enterococcus remains incompletely understood.
  • Vancomycin, a critical last-resort antibiotic, exhibits diminished effectiveness against certain Enterococcus strains.

Purpose of the Study:

  • To investigate the prevalence of glycopeptide-resistant genotypes within Enterococcus species.
  • To identify and quantify key virulence factors in clinical Enterococcus isolates.
  • To explore the association between vancomycin resistance and specific virulence factor genes.

Main Methods:

  • Analysis of 159 Enterococcus strains isolated from nosocomial infections over six months.
  • Utilized multiplex PCR for species identification, detection of glycopeptide resistance genes (e.g., vanA), and 12 distinct virulence factors.
  • Statistical analysis to determine associations between resistance and virulence markers.

Main Results:

  • Enterococcus faecalis and Enterococcus faecium were the predominant species identified.
  • Vancomycin resistance was detected in 10.7% of isolates, with the vanA genotype found in 47% of these resistant strains.
  • Key virulence factors included acm (cell adhesion, 54%), gelE (tissue damage, 66%), cpd (sex pheromone, 64%), and ccf (horizontal gene transfer, 84%). A significant association was observed between acm, ccf, and cpd prevalence in vancomycin-resistant Enterococcus (VRE) isolates.
  • A novel Enterococcus faecium strain (ST2700) exhibiting five virulence factors and the vanA genotype was identified.

Conclusions:

  • Enterococcus faecalis and Enterococcus faecium pose significant clinical challenges due to multidrug resistance and virulence factors like acm, which promotes host colonization.
  • Genes ccf and cpd facilitate the spread of antimicrobial resistance through horizontal gene transfer.
  • The emergence of the virulent, drug-resistant ST2700 strain necessitates immediate surveillance and control strategies.

Related Concept Videos

Modern Molecular Taxonomy01:29

Modern Molecular Taxonomy

Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
145
Applications of Molecular Taxonomy01:20

Applications of Molecular Taxonomy

Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to...
109
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
207