Pollution bactériologique des puits d’eau utilisés par les populations dans la Communauté Urbaine de Douala - Cameroun

Une étude bactériologique a été menée sur 588 échantillons d’eau prélevés dans 49 puits de 7 quartiers de la ville de Douala. Les quartiers ont été choisis suivant la typologie de l’habitat. Les analyses des coliformes ont été faites suivant la technique par inclusion en une couche, et celle des streptocoques par ensemencement dans les tubes à vis avec bouillon de Rothe. Les résultats montrent que ces eaux abritent de nombreuses bactéries pathogènes, coliformes fécaux et streptocoques fécaux. Leurs densités subissent d’importantes fluctuations spatiales et temporelles, et varient entre 200 et 29*105 UFC/100 ml pour les coliformes totaux et entre 30 et 44*103 UFC/100 ml pour les coliformes fécaux ; les streptocoques fécaux sont le plus souvent présents. Les facteurs de variation sont l’environnement du puits, l’entretien, le niveau de la nappe dans le puits, la situation géographique. Les puits les plus contaminés sont ceux qui sont situés à moins de 5 m des sources de pollution telles que les latrines à fond perdu, les dépôts sauvages des ordures ménagères, l’absence ou le traitement régulier de l’eau, le niveau superficiel de l’eau dans le puits. Les puits aménagés, c'est-à-dire munis d’un couvercle bien utilisé et d’une margelle en béton, avec une profondeur d’au moins 4 m, situés au moins à 15 m en amont d’une quelconque source de pollution et dont le traitement est régulier, présentent tous une eau de qualité beaucoup améliorée ; les contaminations fécales y baissent d’au moins 1000 unités. Les points d’eau non aménagés sont très nombreux et les fortes densités de germes dans ces eaux montrent de grands risques sanitaires à court terme pour les consommateurs.© 2009 International Formulae Group. All rights reserved.Mots clés: Zone urbaine pauvre, coliformes totaux, coliformes fécaux, streptocoques fécaux, eaux de puits

Hepatoprotective Effects of Aqueous Extract of Opilia celtidifolia (Opiliaceae) Leaves against Ethanol-Induced Liver Damage in Rats

Objective. Opilia celtidifolia is a plant used in Cameroonian ethnomedicine to cure jaundice. The aim of this study was to evaluate the hepatoprotective activity of O. celtidifolia leaves aqueous extract in rats subjected to ethanol-induced liver damage. Material and Methods. 36 rats including 18 males and 18 females were divided into 6 groups of 3 males and 3 females each, namely, 3 control groups (normal, negative, positive) and 3 test groups. The normal and negative control groups were given distilled water (5 ml/kg), the positive control group received silymarin (100 mg/kg), and the test groups were given O. celtidifolia extract at the doses of 100, 200, and 400 mg/kg. All groups, except the normal control, received concomitantly and daily 40% ethanol (4 g/kg) for 3 weeks to induce hepatotoxicity. Biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, and lipid profile (total cholesterol, HDL, LDL, and triglycerides) were evaluated. Histological sections of the liver, kidneys, and lungs were examined. Qualitative and quantitative phytochemical analysis of the extract were carried out. Results. The groups treated with the extract at the doses of 200 and 400 mg/kg showed a significant decrease (p<0.001) of transaminases (ALT and AST), ALP, and bilirubin compared with the negative control. These results were confirmed by observation of histological sections of the liver that confirmed protective action of extract against ethanol-induced hepatocellular injury. Conclusion. O. celtidifolia possesses hepatoprotective properties that could be related to its high content of tannins and saponins in the leaves aqueous extract

The Mediating Role of Trust and Social Cohesion in the Effects of New Ways of Working: A Dutch Case Study

Purpose-The aim of the chapter is to understand the role of trust and social cohesion in the effects of New Ways of Working. Design-The study consists of a cross-sectional survey (N= 549) at a Dutch insurance company with four locations. NWW was introduced in one of the locations 15 years ago, the other locations only recently. We present and test a model in which trust and social cohesion are mediators between NWW and performance. Findings-The implementation of NWW leads to better performance (Beta 0.16, p <0.001). However, the main effect is explained completely by the mediating role of trust (between employees-managers and between colleagues) and social cohesion. The number of days working at home has no significant relationship to performance. Research implications-The theory and findings of this chapter call for further elaboration in research: more contextualization of these data is needed and more comprehensive theoretical models, such as the role of personality, task and function. Practical implications-If employees feel to be trusted by their supervisors and colleagues, the performance will increase, 'even' if they work at home or in flexible offices. The implementation of NWW will therefore only be beneficial if there are trustful relations and attention is paid to social cohesion of the group. Originality-The study is among the first to prove the relationship between NWW and performance and more importantly, it is one of the first in explaining that relationship by pointing on the mediating role of trust and social cohesion

HIV-1 Drug Susceptibility to Potential Second- and Third-Line Antiretroviral Regimens among Cameroonian Patients: Evidence from a Cross-sectional Design

Scale-up of antiretroviral therapy (ART) and the growing number of long-term treated patients may favor multi-HIV drug resistance (HIVDR) in resource-limited settings. Understanding the burden of HIVDR with ART-exposure may provide new insights for an effective long-term management of infected patients