A total of 183 recent Staphylococcus aureus clinical isolates were tested with three commercially available rapid agglutination methods. The capsular polysaccharide type and resistance to oxacillin of these isolates were also determined. Seven isolates were not identified correctly by agglutination methods. All isolates not identified by the rapid methods were of capsular serotype 5, and of these isolates, six were resistant to oxacillin. The results suggest that these agglutination kits can be improved by the use of antibodies reactive with S. aureus capsular polysaccharide.
The production of the human voice is generated by vocal folds auto-oscillation, due to the interaction between the air flow coming from the lungs and the elastic structure of the vocal folds. The purpose of this thesis is to realise an experimental and theoretical study in order to improve the understanding and modelling of this phenomenon and some of its perturbations.Firstly, the MSePGG algorithm is proposed for the calibration of a non-invasive device for in vivo glottal area measurements. The algorithm is validated on mechanical replicas and illustrated for measurements on human speakers.Secondly, the vocal folds are covered by a thin layer of liquid, essential for phonation. An experimental approach is proposed to systematically study the influence of the presence of liquid on vocal fold replicas. Water spraying is shown to impact basic voice parameter as well as their perturbation. A simplified theoretical flow model accounting for the presence of both air and water is proposed and validated.Thirdly, the effect of vertical vocal fold angular asymmetry, as occurring in the case of unilateral vocal fold paralysis, on the fluid structure interaction is experimentally assessed. It is found that loss of vocal folds full contact leads to important variation on phonation features and their variations.A simple theoretical model is shown to fit the increase of auto-oscillation onset threshold pressure. For future clinical applications obtained results suggest the further development of the MSePGG device and illustrate the multiple of potential causes of voice perturbation.
Abstract Background Increased access to heart valves through early surgery and progress in molecular microbiology have reduced the proportion of infective endocarditis (IE) with no microbiological documentation and increased the proportion of IE associated with unusual microorganisms. Methods We performed an ancillary study of a large prospective population-based survey on IE. Unusual-microorganism IE was defined as definite IE (Duke-Li criteria) due to microorganisms other than streptococci, staphylococci, or enterococci. Results Of 471 cases of documented IE, 46 (9.8%) were due to unusal microorganisms; the following were involved in >1 case: Candida albicans (n = 4), Cutibacterium acnes (n = 4), Pseudomonas aeruginosa (n = 3), Cardiobacterium hominis (n = 3), and Coxiella burnetii (n = 2). Cases were documented with blood cultures (n = 37, 80.4%), heart valve polymerase chain reaction (PCR; n = 5), heart valve culture (n = 2), PCR on vertebral biopsy (n = 1), or serology (n = 1). As compared with IE due to staphylococci, streptococci, or enterococci (n = 420), IE due to unusual microorganisms occurred more frequently in patients with previously known heart disease (69.0% vs 44.3%; P = .002), prosthetic valve (40.5% vs 18.1%; P = .0006), longer duration of fever (mean, 35.1 ± 46.8 days vs 12.5 ± 17.8; P = .003), and who were more often nosocomial (38.1% vs 20.2%; P = .02). Conclusions In this population-based study, 9.8% of IE cases were due to unusual microorganisms, with a predominance of anaerobes, yeast, and gram-negative bacilli. As compared with IE related to staphylococci, streptococci, or enterococci, IE cases related to unusual microorganisms were associated with previously known heart disease, prosthetic valve, longer duration of fever, and nosocomial acquisition. Trial registration ORCID 0000-0003-3617-5411
