Carlos Serna
cserna.bsky.social
Carlos Serna
@cserna.bsky.social
Graduate Teaching Assistant at UCM (Madrid). Interested on epidemiology, bacterial genomics, bioinformatics and AMR 🧬💻🐄
Plot twist 🚨: the very same Tn7734-ICE Tn7740 element turned up in two clonal, vancomycin-resistant E. faecium isolates from a Dutch ICU. This confirms that npmA2 has crossed species lines at least once 🧫⚠️ (9/14)
July 17, 2025 at 12:13 PM
Zooming in on the genetic environment, we found every npmA2 copy in the same vehicle; a 5 kb composite transposon (Tn7734) nested inside a 30 kb ICE element (ICE Tn7740). Both elements are novel, no previous records in public databases 🧬 (8/14)
July 17, 2025 at 12:13 PM
A phylogeny of  ST11 genomes told a different story; no evidence of a single pig‑to‑human transmission event 🐖 🔛 🧑‍🌾. Instead, npmA2 appeared in several distinct local clades, pointing to multiple and independent introductions (caveat: pig isolates remain scarce in public databases) (7/14)
July 17, 2025 at 12:13 PM
Nearly every npmA2‑positive genome belonged to the Clostridioides difficile ST11 lineage (isolates from hospitals 🏥, pig farms 🐷 and even water 💧 in the US, UK and Germany). That led to the next question; how did this rare gene reach ST11? (5/14)
July 17, 2025 at 12:13 PM