Pan-genome multilocus sequence typing and outbreak-specific reference-based single nucleotide polymorphism analysis to resolve two concurrent Staphylococcus aureus outbreaks in neonatal services.

We used a two-step whole genome sequencing analysis for resolving two concurrent outbreaks in two neonatal services in Belgium, caused by exfoliative toxin A-encoding-gene-positive (eta+) methicillin-susceptible Staphylococcus aureus with an otherwise sporadic spa-type t209 (ST-109). Outbreak A involved 19 neonates and one healthcare worker in a Brussels hospital from May 2011 to October 2013. After a first episode interrupted by decolonization procedures applied over 7 months, the outbreak resumed concomitantly with the onset of outbreak B in a hospital in Asse, comprising 11 neonates and one healthcare worker from mid-2012 to January 2013. Pan-genome multilocus sequence typing, defined on the basis of 42 core and accessory reference genomes, and single-nucleotide polymorphisms mapped on an outbreak-specific de novo assembly were used to compare 28 available outbreak isolates and 19 eta+/spa-type t209 isolates identified by routine or nationwide surveillance. Pan-genome multilocus sequence typing showed that the outbreaks were caused by independent clones not closely related to any of the surveillance isolates. Isolates from only ten cases with overlapping stays in outbreak A, including four pairs of twins, showed no or only a single nucleotide polymorphism variation, indicating limited sequential transmission. Detection of larger genomic variation, even from the start of the outbreak, pointed to sporadic seeding from a pre-existing exogenous source, which persisted throughout the whole course of outbreak A. Whole genome sequencing analysis can provide unique fine-tuned insights into transmission pathways of complex outbreaks even at their inception, which, with timely use, could valuably guide efforts for early source identification.

Fear-relevant images as conditioned stimuli for somatic complaints, respiratory behavior, and reduced end-tidal pCO2.

Two fear-relevant imagery scripts were used as conditioned stimuli (CSs) in a differential learning paradigm with 5.5% CO2-enriched air as unconditioned stimulus (US). In another condition, 2 neutral scripts were used as CSs (N = 56). Within each condition, one script was imagined while breathing the CO2-enriched air (CS+/US trial), the other while breathing room air (CS- trial). Three CS+ and 3 CS- trials were run in an acquisition phase, followed by 2 CS+ and 2 CS- test trials (imagining the scripts while breathing air). Respiratory behavior, end-tidal CO2, and heart rate were measured throughout the experiment; subjective symptoms were measured after each trial. The type of imagery had strong effects on symptoms and physiological responses. A selective conditioning effect was also observed: CS+ imagery produced more symptoms and altered respiratory behavior compared with CS- imagery, but only in the fear-relevant script condition. The findings are discussed as to their relevance for panic and agoraphobic anxiety.

Angiotensin II-induced rhythmic jaw movements in the ketamine-anesthetized guinea pig.

The EMG activity of the left anterior digastric muscle as well as associated jaw movements were studied in ketamine-anesthetized guinea pigs that had received i.v. infusions of angiotensin II (ANG-II). Rhythmic jaw movements with two distinct movement profiles were associated with ANG-II infusion. One movement profile was typified by vertical jaw opening and closing movements with little or no associated horizontal movement. The second rhythmical jaw movement profile was unlike the first in that jaw closing was accompanied by a significant horizontal deflection of the jaw. Both jaw movement profiles were similar in that little or no horizontal movement occurred during jaw opening. Tongue protrusions were also observed during jaw opening in both cases. The results show that ANG-II induces rhythmic jaw movements in anesthetized guinea pigs. ANG-II-induced jaw movement profiles and digastric muscle EMG activity are similar to those seen after an i.v. injection of apomorphine in the anesthetized guinea pig, and to those associated with lapping in the awake animal.