Sero-Epidemiology as a Tool to Screen Populations for Exposure to Mycobacterium ulcerans

Sero-epidemiological analyses revealed that a higher proportion of sera from individuals living in the Buruli ulcer (BU) endemic Densu River Valley of Ghana contain Mycobacterium ulcerans 18 kDa small heat shock protein (shsp)-specific IgG than sera from inhabitants of the Volta Region, which was regarded so far as BU non-endemic. However, follow-up studies in the Volta Region showed that the individual with the highest anti-18 kDa shsp-specific serum IgG titer of all participants from the Volta Region had a BU lesion. Identification of more BU patients in the Volta Region by subsequent active case search demonstrated that sero-epidemiology can help identify low endemicity areas. Endemic and non-endemic communities along the Densu River Valley differed neither in sero-prevalence nor in positivity of environmental samples in PCR targeting M. ulcerans genomic and plasmid DNA sequences. A lower risk of developing M. ulcerans disease in the non-endemic communities may either be related to host factors or a lower virulence of local M. ulcerans strains

Development of a temperature-switch PCR-based SNP typing method for Mycobacterium ulcerans

Mycobacterium ulcerans (M. ulcerans), the causative agent of the devastating skin disease Buruli ulcer (BU), is characterized by an extremely low level of genetic diversity. Recently, we have reported the first discrimination of closely related M. ulcerans variants in the BU endemic Densu River Valley of Ghana. In the study real-time PCR-based single nucleotide polymorphism (SNP) typing at 89 predefined loci revealed the presence of ten M. ulcerans haplotypes circulating in the BU endemic region. Here we describe the development of temperature-switch PCR (TSP) assays that allow distinguishing these haplotypes by conventional agarose gel-based analysis of the PCR products. After validation of the accuracy of typing results, the TSP assays were successfully established in a reference laboratory in Ghana. Development of the cost-effective and rapid TSP-based genetic fingerprinting method will thus allow investigating the spread of M. ulcerans clones by regular genetic monitoring in BU endemic countries

Synthesis and applications of amino-functionalized carbon nanomaterials

Carbon-based nanomaterials (CNMs) have attracted considerable attention in the scientific community both from a scientific and an industrial point of view. Fullerenes, carbon nanotubes (CNTs), graphene and carbon dots (CDs) are the most popular forms and continue to be widely studied. However, the general poor solubility of many of these materials in most common solvents and their strong tendency to aggregate remains a major obstacle in practical applications. To solve these problems, organic chemistry offers formidable help, through the exploitation of tailored approaches, especially when aiming at the integration of nanostructures in biological systems. According to our experience with carbon-based nanostructures, the introduction of amino groups is one of the best trade-offs for the preparation of functionalized nanomaterials. Indeed, amino groups are well-known for enhancing the dispersion, solubilization, and processability of materials, in particular of CNMs. Amino groups are characterized by basicity, nucleophilicity, and formation of hydrogen or halogen bonding. All these features unlock new strategies for the interaction between nanomaterials and other molecules. This integration can occur either through covalent bonds (e.g., via amide coupling) or in a supramolecular fashion. In the present Feature Article, the attention will be focused through selected examples of our approach to the synthetic pathways necessary for the introduction of amino groups in CNMs and the subsequent preparation of highly engineered ad hoc nanostructures for practical applications. This journal i

Western blot analysis of anti-<i>P. falciparum</i> MSP-1 IgG responses in children.

<p>Sera from children living in Mbandji 2 were tested for IgG responses against a domain of the <i>P. falciparum</i> MSP-1 protein by Western Blot analysis. Specific bands were detected in the majority of individuals of all tested age groups above 1 year. The band corresponding to the specific signal of the MSP-1 protein domain is indicated with an arrow.</p

Age distribution of study participants.

<p><b>A</b> In Cameroon, serum samples were collected from 395 healthy individuals from the BU endemic village of Mbandji 2. <b>B</b> In the Obom sub-district of the Ga-South district in Ghana, blood sera were collected from 96 BU patients (black) and 384 control individuals (grey) of the different age groups shown.</p

Changes in anti-<i>M. ulcerans</i> 18 kDa shsp IgG titres in sequentially collected serum samples.

<p><b>A</b> IgG titres against the <i>M. ulcerans</i> 18 kDa shsp were determined in serial serum samples collected from 80 individuals. The majority of changes were small and most individuals showed a slightly decreased titre after one year. <b>B</b> Boxplot of differences in OD values between the two samples are shown by age group. Changes in antibody titres were most pronounced in young adults.</p

Age distribution of BU incidence and anti-18 kDa shsp IgG serum titres among healthy inhabitants of Mbandji 2.

<p><b>A</b> Incidence of reported BU by age in the Bankim Health District (March 2010 – May 2013). <b>B</b> Boxplot of OD values of 1∶100 diluted serum samples from inhabitants of Mbandji 2 tested in an anti-<i>M. ulcerans</i> 18 kDa shsp IgG specific ELISA by age group. No IgG titres above the background level were observed for children below the age of four. The background response (OD<0.35) is indicated as a dotted line.</p