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lsa (E) is a pleuromutilin, lincosamide, and streptogramin A (PLSA phenotype) resistance gene that was first described in S. aureus and was thought to have been transferred from Enterococcus sp. This study aimed to elucidate the prevalence of the lsa (E) gene among E. faecium isolates at a tertiary teaching hospital and to evaluate the transferability of the lsa (E) gene from E. faecium to S. aureus in vitro. A total of 96 E. faecium strains isolated from one hospital in Beijing in 2013 were analysed for quinupristin-dalfopristin (QDA) resistance genes, and multilocus sequence typing (MLST) was performed. The transferability of QDA resistance between ten E. faecium strains and four S. aureus strains was determined by filter mating. Genome sequencing of the transconjugant was performed. A total of 46 E. faecium isolates (46/96, 47.92%) tested positive for lsa (E), while two isolates (2/96, 2.08%) tested positive for lsa (A). Thirty-six lsa (E)-positive strains (36/46, 78.3%) belonged to ST78. Among 40 mating tests, lsa (E) was successfully transferred through one conjugation at a frequency of 1.125 × 10–7 transconjugants per donor. The QDA resistance of the transconjugant N7435-R3645 was expressed at a higher level (MIC = 16 mg/L) than that of the parent S. aureus strain (MIC = 0.38 mg/L). Next-generation sequencing (NGS) analysis of the transconjugant N7435-R3645 showed that the complete sequence of the lsa (E)-carrying plasmid pN7435-R3645 had a size of 92,396 bp and a G + C content of 33% (accession no. MT022086). The genetic map of pN7435-R3645 had high nucleotide similarity and shared the main open reading frame (ORF) features with two plasmids: E. faecium pMG1 (AB206333.1) and E. faecium LS170308 (CP025078.1). The rep gene of pN7435-R3645 showed 100% identity with that of pMG1, although it did not belong to the rep 1-19 family but instead a unique rep family. Multiple antibiotic resistance genes, including lsa (E), aadE and lnu (B), erm (B), ant6 -Ia, and lnu (B), were present on the plasmid. In conclusion, an lsa (E)-carrying plasmid that can be transferred by conjugation from E. faecium to S. aureus in vitro was identified. This multidrug resistance (MDR) pMG1-like plasmid may act as a vector in the dissemination of antimicrobial resistance among species. [ABSTRACT FROM AUTHOR]

Beijing Isotope-Separation-On-Line neutron-rich beam facility (BISOL) is proposed as a double drive radioactive ion beams (RIBs) facility using both a nuclear reactor and a deuteron linear accelerator. The accelerator driven neutron source will be a so called IFMIF-like intense neutron source. To satisfy the requirement of neutron production from a 40 MeV, 50 mA (corresponding to 2 MW) deuteron beam, a windowless liquid lithium target has been adopted as the high-power neutron converter for this facility. The preliminary conceptual design of the target is described. Hydraulic and thermodynamic calculations have been carried out using computational fluid dynamics (CFD) method. The lithium fluid stability and the impact of beam momentum transfer are discussed. [ABSTRACT FROM AUTHOR]