VanA-type vancomycin-resistant Enterococcus faecium ST1336 isolated from mussels in an anthropogenically impacted...

Area of Science:

• Microbiology
• Environmental Science
• Food Safety

Background:

• Enterococcus faecium is a significant cause of hospital-acquired infections.
• Vancomycin resistance in Enterococcus faecium (VRE) is a growing public health concern.
• Environmental reservoirs for VRE are increasingly being investigated.

Purpose of the Study:

• To identify and characterize multidrug-resistant vancomycin-resistant Enterococcus faecium (VRE) in marine mussels.
• To investigate the genomic features and genetic elements associated with VRE found in mussels.
• To assess the potential role of mussels as a dissemination source for VRE in coastal ecosystems.

Main Methods:

• Sampling of marine brown mussels (Perna perna) from anthropogenically affected coastal waters in Brazil.
• Isolation and identification of Enterococcus faecium.
• Genomic analysis including whole-genome sequencing to determine sequence type and identify resistance genes and mobile genetic elements.
• Detection of the vanA gene and Tn1546-like elements.

Main Results:

• The occurrence of multidrug-resistant vancomycin-resistant Enterococcus faecium (VRE) carrying the vanA gene was confirmed in Perna perna mussels.
• A novel sequence type, ST1336, was identified for the VRE isolates.
• The VRE isolates harbored a Tn1546-like element, a known mobile genetic element associated with vancomycin resistance.
• The mussels were sourced from coastal waters impacted by anthropogenic activities.

Conclusions:

• Marine mussels from anthropogenically affected areas can harbor multidrug-resistant VRE.
• The identification of a novel VRE sequence type (ST1336) in mussels suggests environmental adaptation or introduction.
• Mussels represent a potential pathway for VRE dissemination within marine ecosystems.
• These findings have implications for seafood safety, quality, and the broader environmental surveillance of antimicrobial resistance.