Comparison of microbiological and molecular diagnosis for identification of respiratory secondary infections in COVID-19 patients and their antimicrobial resistance patterns

Diagn Microbiol Infect Dis. 2024 Oct;110(2):116479. doi: 10.1016/j.diagmicrobio.2024.116479. Epub 2024 Aug 3.

Abstract

We report the use of a new multiplex Real-Time PCR platform to simultaneously identify 24 pathogens and 3 antimicrobial-resistance genes directly from respiratory samples of COVID-19 patients. Results were compared to culture-based diagnosis. Secondary infections were detected in 60% of COVID-19 patients by molecular analysis and 73% by microbiological assays, with no significant differences in accuracy, indicating Gram-negative bacteria as the predominant species. Among fungal superinfections, Aspergillus spp. were detected by both methods in more than 7% of COVID-19 patients. Oxacillin-resistant S. aureus and carbapenem-resistant K. pneumoniae were highlighted by both methods. Secondary microbial infections in SARS-CoV-2 patients are associated with poor outcomes and an increased risk of death. Since PCR-based tests significantly reduce the turnaround time to 4 hours and 30 minutes (compared to 48 hours for microbial culture), we strongly support the routine use of molecular techniques, in conjunction with microbiological analysis, to identify co/secondary infections.

Keywords: Real-Time PCR; SARS-CoV-2; antimicrobial-resistance; culture-based diagnosis; molecular-based syndromic test; secondary infection.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Bacteria / classification
  • Bacteria / drug effects
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Bacterial Infections / diagnosis
  • Bacterial Infections / microbiology
  • COVID-19* / diagnosis
  • COVID-19* / microbiology
  • Coinfection* / diagnosis
  • Coinfection* / microbiology
  • Coinfection* / virology
  • Drug Resistance, Bacterial / genetics
  • Female
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Molecular Diagnostic Techniques / methods
  • Multiplex Polymerase Chain Reaction / methods
  • Real-Time Polymerase Chain Reaction / methods
  • Respiratory Tract Infections / diagnosis
  • Respiratory Tract Infections / microbiology
  • Respiratory Tract Infections / virology
  • SARS-CoV-2* / genetics

Substances

  • Anti-Bacterial Agents