Detection of methicillin resistance of Staphylococcus aureus in vitreous humor using MALDI-TOF MS and Fc-MBL@Fe3O4 enrichment

Sci Rep. 2024 Dec 28;14(1):30757. doi: 10.1038/s41598-024-80715-5.

Abstract

Endophthalmitis is a serious infectious eye disease that causes permanent vision loss. This study developed a method for rapid identification and drug resistance analysis of pathogens in vitreous humor. After short-term rapid culture, 30 Staphylococcus aureus isolates were enriched and purified from the vitreous humor using Fc-MBL@Fe3O4, and then identified by MALDI-TOF MS. The bacterial solution was adjusted to 106 CFU/mL and mixed with CAMHB containing cefoxitin (4 µg/mL) at the same volume. After culture, it was enriched by Fc-MBL@Fe3O4 and identified by MALDI-TOF MS. MRSA was judged according to whether the bacteria could successfully be identified. The enrichment efficiency of Fc-MBL@Fe3O4 for S. aureus in CAMHB was 88.1%. The detection rate of S. aureus reached 100% after 8 h of vitreous humor culture. The best test performance was achieved with Fc-MBL@Fe3O4 enrichment after a 3 h incubation. At this time point, 96.7% validity, 100% sensitivity, and 100% specificity were achieved. Thus, the identification and drug resistance analysis of S. aureus (51-110 CFU) in vitreous humor was completed within 11 h. This study provides a new method for rapid clinical diagnosis of endophthalmitis and precise treatment with antibiotics.

Keywords: MALDI-TOF MS; MRSA; Magnetic enrichment; Pathogen identification; Vitreous humor.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Endophthalmitis / diagnosis
  • Endophthalmitis / drug therapy
  • Endophthalmitis / microbiology
  • Humans
  • Methicillin-Resistant Staphylococcus aureus* / drug effects
  • Methicillin-Resistant Staphylococcus aureus* / isolation & purification
  • Microbial Sensitivity Tests
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization* / methods
  • Staphylococcal Infections / diagnosis
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / drug effects
  • Staphylococcus aureus / isolation & purification
  • Vitreous Body* / microbiology

Substances

  • Anti-Bacterial Agents