Detection of an <i>Enterococcus faecium</i> Carrying a Double Copy of the <i>PoxtA</i> Gene from Freshwater River, Italy

• Main Authors: Marzia Cinthi (Author), Sonia Nina Coccitto (Author), Gianluca Morroni (Author), Gloria D'Achille (Author), Andrea Brenciani (Author), Eleonora Giovanetti (Author)
• Format: Book
• Published: MDPI AG, 2022-11-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Oxazolidinones are valuable antimicrobials that are used to treat severe infections due to multidrug-resistant (MDR) Gram-positive bacteria. However, in recent years, a significant spread of clinically relevant linezolid-resistant human bacteria that is also present in animal and environmental settings has been detected and is a cause for concern. This study aimed to investigate the presence, genetic environments, and transferability of oxazolidinone resistance genes in enterococci from freshwater samples. A total of 10 samples were collected from a river in Central Italy. Florfenicol-resistant enterococci were screened for the presence of oxazolidinone resistance genes by PCR. <i>Enterococcus faecium</i> M1 was positive for the <i>poxtA</i> gene. The <i>poxtA</i> transfer (filter mating and aquaria microcosm assays), localization (S1-PFGE/hybridization), genetic context, and clonality of the isolate (WGS) were analyzed. Two <i>poxtA</i> copies were located on the 30,877-bp pEfM1, showing high-level identity and synteny to the pEfm-Ef3 from an <i>E. faecium</i> collected from an Italian coastal area. The isolate was able to transfer the <i>poxtA</i> to enterococcal recipients both in filter mating and aquaria microcosm assays. This is-to the best of our knowledge-the first detection of an enterococcus carrying a linezolid resistance gene from freshwater in Italy.

Item Description

10.3390/antibiotics11111618
2079-6382