Campylobacter Spp. Epidemiology and Antimicrobial Susceptibility in a Developing Country, Burkina Faso (West Africa)

Data on campylobacteriosis are almost nonexistent in Burkina Faso. In this study conducted from 2006 to 2008 in Ouagadougou, stool specimens and sociodemographic data were collected from 1 246 patients attending the university teaching hospital for enteritis. Stool samples were analyzed for the presence of Campylobacter by the direct culture method on selective mCCDA agar followed by antibiotic susceptibility testing on the isolated strains. The isolation rate of Campylobacter was 2.3%,comprising of the following species C. jejuni (51.8%), C. coli (13.8%), and C. upsaliensis (3.5%). However, 30.9% of the isolates were unidentified. No resistant strain was found to gentamicin. The resistance to amoxicillin+clavulanic acid (3.4%) was lower than those (10.3-34.5%) to the other antibiotics: erythromycin (10.3%), tetracycline (10.3%), ciprofloxacin (13.8%), amoxicillin (24.1%) and ceftriaxone (34.5%), nalidixic acid (34.5%). Significant associations were found between Campylobacter enteritis and contact with animals (P=0.03), and HIV infection (P<0.0001), in contrast to other sociodemographic and seasonal factors. From the data obtained Amoxicillin+clavulanic acid appear to be the first choice for treatment. The implementation of a national program may be helpful in controlling the spread of the disease and the increase of resistance to antibiotics.Keywords: Campylobacter, epidemiology, HIV, drug resistance, Burkina Fas

Observatoires de la gratuité des soins au Mali : émergence, processus et résultats préliminaires

Due to copyright restrictions, this item cannot be sharedLe Mali s’est engagé, depuis le début des années 2000, dans plusieurs nouvelles politiques d’exemption du paiement des soins (dites de gratuité). Pour mieux comprendre ces politiques, le ministère de la santé a mis en place des observatoires de la gratuité des soins. Cette note d’information présente ce projet et livre quelques résultats préliminaires

Spatial swarm segregation and reproductive isolation between the molecular forms of Anopheles gambiae

Anopheles gambiae, the major malaria vector in Africa, can be divided into two subgroups based on genetic and ecological criteria. These two subgroups, termed the M and S molecular forms, are believed to be incipient species. Although they display differences in the ecological niches they occupy in the field, they are often sympatric and readily hybridize in the laboratory to produce viable and fertile offspring. Evidence for assortative mating in the field was recently reported, but the underlying mechanisms awaited discovery. We studied swarming behaviour of the molecular forms and investigated the role of swarm segregation in mediating assortative mating. Molecular identification of 1145 males collected from 68 swarms in Donéguébougou, Mali, over 2 years revealed a strict pattern of spatial segregation, resulting in almost exclusively monotypic swarms with respect to molecular form. We found evidence of clustering of swarms composed of individuals of a single molecular form within the village. Tethered M and S females were introduced into natural swarms of the M form to verify the existence of possible mate recognition operating within-swarm. Both M and S females were inseminated regardless of their form under these conditions, suggesting no within-mate recognition. We argue that our results provide evidence that swarm spatial segregation strongly contributes to reproductive isolation between the molecular forms in Mali. However this does not exclude the possibility of additional mate recognition operating across the range distribution of the forms. We discuss the importance of spatial segregation in the context of possible geographic variation in mechanisms of reproductive isolation

Testing of Aerosols for Lung Toxicity by In-Vitro Studies at the Air-Liquid Interface for up to 24 Hours

The state of the art of studying the health effects of aerosols in vitro is based on submerged exposure of collected particulate matter, suspended in culture medium. However, this method neglects the gas phase including their interactions with particles and cells. It may change the properties of the investigated particles and does not represent the actual process in the human lung. Exposure at the Air-Liquid Interface (ALI) avoids these disadvantages, but requires a comprehensive system to guarantee reproducible conditions. Therefore, KIT and VITROCELL Systems developed a fully automated ALI exposure station. The exposure station offers a complete measurement system for parallel exposure of up to 24 human lung cell cultures towards gases, nanoparticles and complex mixtures such as combustion aerosols. The aerosol flow, temperature, and humidity are adjusted to the conditions resembling the human lung. An internal negative control using humidified synthetic air is also implemented and the particle dose per time can be increased by electrostatic particle deposition. The particle mass per area deposited by diffusional as well as by electrostatic mechanism is monitored online using a quartz crystal microbalance. Additionally, a new tool to reproducibly expose sample grids for transmission electron microscopy was developed and applied. Image evaluation of TEM images delivers dose information with respect to the spatial distribution and the agglomeration state of the deposited particles. Applications of the ALI exposure station are environmental atmospheres and technical emission sources like marine diesel engines or wood combustion. Long-term stability of A549 lung cells was examined for exposure times up to 24 hours by exposing A549 cell cultures towards clean air as well as towards airborne titanium dioxide and copper oxide nanoparticles. Dose measurement data and biological responses as viability (AlamarBlue assay), cytotoxicity (LDH release), and release of cytokines during long-term exposure are reported

Spatial distribution and male mating success of Anopheles gambiae swarms

<p>Abstract</p> <p>Background</p> <p><it>Anopheles gambiae </it>mates in flight at particular mating sites over specific landmarks known as swarm markers. The swarms are composed of males; females typically approach a swarm, and leave <it>in copula</it>. This mating aggregation looks like a lek, but appears to lack the component of female choice. To investigate the possible mechanisms promoting the evolution of swarming in this mosquito species, we looked at the variation in mating success between swarms and discussed the factors that structure it in light of the three major lekking models, known as the female preference model, the hotspot model, and the hotshot model.</p> <p>Results</p> <p>We found substantial variation in swarm size and in mating success between swarms. A strong correlation between swarm size and mating success was observed, and consistent with the hotspot model of lek formation, the <it>per capita </it>mating success of individual males did not increase with swarm size. For the spatial distribution of swarms, our results revealed that some display sites were more attractive to both males and females and that females were more attracted to large swarms. While the swarm markers we recognize help us in localizing swarms, they did not account for the variation in swarm size or in the swarm mating success, suggesting that mosquitoes probably are attracted to these markers, but also perceive and respond to other aspects of the swarming site.</p> <p>Conclusions</p> <p>Characterizing the mating system of a species helps understand how this species has evolved and how selective pressures operate on male and female traits. The current study looked at male mating success of <it>An. gambiae </it>and discussed possible factors that account for its variation. We found that swarms of <it>An. gambiae </it>conform to the hotspot model of lek formation. But because swarms may lack the female choice component, we propose that the <it>An. gambiae </it>mating system is a lek-like system that incorporates characteristics pertaining to other mating systems such as scramble mating competition.</p