Details

Autor(en) / Beteiligte

• Janice, Jessin
• Wagner, Theresa Maria
• Olsen, Karina
• Hegstad, Joachim
• Hegstad, Kristin

Titel

Emergence of vancomycin-resistant enterococci from vancomycin-susceptible enterococci in hospitalized patients under antimicrobial therapy

Ist Teil von

• Journal of global antimicrobial resistance., 2024-03, Vol.36, p.116-122

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2024

Quelle

MEDLINE

Beschreibungen/Notizen

• •Vancomycin-resistant isolates emerge after vancomycin therapy within the patient.•In case 1, chromosomal integration of vanB-Tn1549 occurred in an ST192 strain.•In case 2, a vanB-Tn1549-carrying plasmid was acquired in an ST80 and ST117 strain.•The vanB-ST117 strain persists several months after discharge from the hospital. Enterococci are opportunistic pathogens with plastic genomes that evolve, acquire, and transmit antimicrobial-resistant determinants such as vancomycin resistance clusters. While vancomycin-resistant enterococci (VRE) have emerged as successful nosocomial pathogens, the mechanism by which vancomycin-susceptible enterococci (VSE) transform to VRE in hospitalized patients remains understudied. Genomes of Enterococcus faecium from two critically ill hospitalized patients subjected to multiple antibiotic therapies, including broad-spectrum antibiotics, were investigated. To identify mechanisms of resistance evolution, genomes of vancomycin-susceptible and -resistant isolates were compared. While VSE isolates were initially identified, VRE strains emerged post-vancomycin therapy. Comparative genomics revealed horizontal transmission of mobile genetic elements containing the Tn1549 transposon, which harbours the vanB-type vancomycin resistance gene cluster. This suggests that broad-spectrum antibiotic stress promoted the transfer of resistance-conferring elements, presumably from another gut inhabitant. This is one of the first studies investigating VSE and VRE isolates from the same patient. The mechanism of transmission and the within-patient evolution of vancomycin resistance via mobile genetic elements under antibiotic stress is illustrated. Our findings serve as a foundation for future studies building on this knowledge which can further elucidate the dynamics of antibiotic stress, resistance determinant transmission, and interactions within the gut microbiota. [Display omitted]