Characterization of Staphylococcus aureus from Pasteur Institute in Côte d'Ivoire: Methicillin Resistance, Reduced Sensitivity to Vancomycin, Panton-Valentine Leucotoxin and Exfoliatins.

Staphylococcus aureus, which causes various infections, particularly suppurations, expresses many virulence factors. The resistance of S. aureus to methicillin (MRSA) which can spread to vancomycin constitutes a major challenge in infectiology. The search for virulence and resistance factors is therefore of interest to better understand the mechanisms of this pathogenicity. The objectives of this study were to determine the frequency of phenotypic and genotypic (mecA, vanB) resistances, the frequency of virulence genes (eta, etb, and lukS) and to investigate the resistant strains for the presence of virulence genes. On thirty-one strains isolated from infections at the Pasteur Institute of Côte d'Ivoire, the study of susceptibility to methicillin and vancomycin was carried out by phenotypic and molecular methods. We observed phenotypic and genotypic resistance to methicillin of 41.9% and 32.3% respectively. Despite a suspicion of very high vancomycin susceptibility reduced, 25.8% by phenotypic method, the vanB gene was only found in 3.2% of strains. The prevalence of virulence genes was high with the eta gene, 96.8%, and the lukS gene 45.2%. The mecA gene was present with an eta gene in 32.3% of strains and in 9.7% with the lukS gene, however the vanB gene was not present in any strain carrying virulence factors. These results should lead to the screening of other van genes for resistance to vancomycin.

Factor structure of self-rating depression scale by Zung and prevalence of depressive state of night shift workers.

The Zung self-rating depression scale (SDS) was applied to Japanese night shift workers of a railway company in order to assess the prevalence of depressive state and clarify the structural characteristics of the SDS questionnaire. Out of 2,394 employees, 1,931 male workers were engaged in night shift work and 1,274 men (66.0%) completely answered the questionnaire. The control group was selected from daytime workers. The average age of the subjects was 39.4. Cronbach's alpha coefficient of the night shift workers was 0.835 and that of the control was 0.848. SDS index decreased with age. The mild, moderate, and severe depressive state of night shift workers evaluated by SDS were 13.7%, 2.1%, and 0.6%, respectively. A two-way analysis of variance on SDS index examined age and shift work. Age influenced SDS index, but there was no interaction between the factors. Two factors were extracted by factor analysis. Factor 1 consisted of 8 positive items, accounting for 16.7%. Factor 2 consisted of 8 depressive items, accounting for 15.6%. The residual four items consisted of somatic or behavioral features. Mean value of SDS index by age, distribution of SDS index, and factor structure of SDS questions of the night shift workers were similar to those of the control group.