Phylogenetic Analysis of Staphylococcus aureus CC398 Reveals a Sub-Lineage Epidemiologically Associated with Infections in Horses

In the early 2000s, a particular MRSA clonal complex (CC398) was found mainly in pigs and pig farmers in Europe. Since then, CC398 has been detected among a wide variety of animal species worldwide. We investigated the population structure of CC398 through mutation discovery at 97 genetic housekeeping loci, which are distributed along the CC398 chromosome within 195 CC398 isolates, collected from various countries and host species, including humans. Most of the isolates in this collection were received from collaborating microbiologists, who had preserved them over years. We discovered 96 bi-allelic polymorphisms, and phylogenetic analyses revealed that an epidemic sub-clone within CC398 (dubbed 'clade (C)') has spread within and between equine hospitals, where it causes nosocomial infections in horses and colonises the personnel. While clade (C) was strongly associated with S. aureus from horses in veterinary-care settings (p = 2 × 10(-7)), it remained extremely rare among S. aureus isolates from human infections

Effects of animacy and noun-phrase relatedness on the processing of complex sentences

Previous work has suggested that syntactically complex object-extracted relative clauses are easier to process when the head noun phrase (NP1) is inanimate and the embedded noun phrase (NP2) is animate compared to the reverse animacy configuration, with differences in processing difficulty beginning as early as NP2 (e.g., The article that the senator… versus The senator that the article…). Two eye-tracking-while-reading experiments were conducted to better understand the source of this effect. Experiment 1 showed that having an inanimate NP1 facilitated processing even when NP2 was held constant. Experiment 2 manipulated both animacy of NP1 and the degree of semantic relatedness between the critical NPs. When NP1 and NP2 were paired arbitrarily, the early animacy effect emerged at NP2. When NP1 and NP2 were semantically related, this effect disappeared, with effects of NP1 animacy emerging in later processing stages for both the Related and Arbitrary conditions. The results indicate that differences in the animacy of NP1 influence early processing of complex sentences only when the critical NPs share no meaningful relationship

Rapid Differentiation between Livestock-Associated and Livestock-Independent Staphylococcus aureus CC398 Clades

Staphylococcus aureus clonal complex 398 (CC398) isolates cluster into two distinct phylogenetic clades based on single-nucleotide polymorphisms (SNPs) revealing a basal human clade and a more derived livestock clade. The scn and tet(M) genes are strongly associated with the human and the livestock clade, respectively, due to loss and acquisition of mobile genetic elements. We present canonical single-nucleotide polymorphism (canSNP) assays that differentiate the two major host-associated S. aureus CC398 clades and a duplex PCR assay for detection of scn and tet (M). The canSNP assays correctly placed 88 S. aureus CC398 isolates from a reference collection into the human and livestock clades and the duplex PCR assay correctly identified scn and tet(M). The assays were successfully applied to a geographically diverse collection of 272 human S. aureus CC398 isolates. The simple assays described here generate signals comparable to a whole-genome phylogeny for major clade assignment and are easily integrated into S. aureus CC398 surveillance programs and epidemiological studies. © 2013 Stegger et al.SCOPUS: ar.jinfo:eu-repo/semantics/publishe