Dengue and chikungunya are increasing global public health concerns due to their rapid geographical spread and increasing disease burden. Knowledge of the contemporary distribution of their shared vectors, Aedes aegypti and Aedes albopictus remains incomplete and is complicated by an ongoing range expansion fuelled by increased global trade and travel. Mapping the global distribution of these vectors and the geographical determinants of their ranges is essential for public health planning. Here we compile the largest contemporary database for both species and pair it with relevant environmental variables predicting their global distribution. We show Aedes distributions to be the widest ever recorded; now extensive in all continents, including North America and Europe. These maps will help define the spatial limits of current autochthonous transmission of dengue and chikungunya viruses. It is only with this kind of rigorous entomological baseline that we can hope to project future health impacts of these viruses.

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The global distribution of the arbovirus vectors Aedes aegypti and Ae. Albopictus

Epithelial cells can respond to conserved bacterial products that are internalized after either bacterial invasion or liposome treatment of cells. We report here that the noninvasive Gram-negative pathogen Helicobacter pylori was recognized by epithelial cells via Nod1, an intracellular pathogen-recognition molecule with specificity for Gram-negative peptidoglycan. Nod1 detection of H. pylori depended on the delivery of peptidoglycan to host cells by a bacterial type IV secretion system, encoded by the H. pylori cag pathogenicity island. Consistent with involvement of Nod1 in host defense, Nod1-deficient mice were more susceptible to infection by cag pathogenicity island-positive H. pylori than were wild-type mice. We propose that sensing of H. pylori by Nod1 represents a model for host recognition of noninvasive pathogens.

Nod1 responds to peptidoglycan delivered by the Helicobacter pylori cag pathogenicity island

The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus

A Zika virus (ZIKAV) outbreak started in October 2013 in French Polynesia, South Pacific. We describe here the clinical and laboratory features of two mothers and their newborns who had ZIKAV infection as confirmed by ZIKAV RT-PCR performed on serum collected within four days post-delivery in date. The infants' infection most probably occurred by transplacental transmission or during delivery. Attention should be paid to ZIKAV-infected pregnant women and their newborns, as data on the impact on them are limited. .

Evidence of perinatal transmission of Zika virus, French Polynesia, December 2013 and February 2014.

There has been growing interest in Europe in recent years in the establishment and spread of invasive mosquitoes, notably the incursion of Aedes albopictus through the international trade in used tires and lucky bamboo, with onward spread within Europe through ground transport. More recently, five other non-European aedine mosquito species have been found in Europe, and in some cases populations have established locally and are spreading. Concerns have been raised about the involvement of these mosquito species in transmission cycles of pathogens of public health importance, and these concerns were borne out following the outbreak of chikungunya fever in Italy in 2007, and subsequent autochthonous cases of dengue fever in France and Croatia in 2010. This article reviews current understanding of all exotic (five introduced invasive and one intercepted) aedine species in Europe, highlighting the known import pathways, biotic and abiotic constraints for establishment, control strategies, and public health significance, and encourages Europe-wide surveillance for invasive mosquitoes.

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A review of the invasive mosquitoes in Europe: ecology, public health risks, and control options.

In September 2010, autochthonous transmission of chikungunya virus was recorded in southeastern France, where the Aedes albopictus mosquito vector is present. Sequence analysis of the viral genomes of imported and autochthonous isolates indicated new features for the potential emergence and spread of the virus in Europe.

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Chikungunya virus, southeastern France.

Constitutive expression of γ-glutamyltranspeptidase (GGT) activity is common to all Helicobacter pylori strains, and is used as a marker for identifying H. pylori isolates. Helicobacter pylori GGT was purified from sonicated extracts of H. pylori strain 85P by anion exchange chromatography. The N-terminal amino acid sequences of two of the generated endoproteolysed peptides were determined, allowing the cloning and sequencing of the corresponding gene from a genomic H. pylori library. The H. pylori ggt gene consists of a 1681 basepair (bp) open reading frame encoding a protein with a signal sequence and a calculated molecular mass of 61 kDa. Escherichia coli clones harbouring the H. pylori ggt gene exhibited GGT activity at 37°C, in contrast to E. coli host cells (MC1061, HB101), which were GGT negative at 37°C. GGT activity was found to be constitutively expressed by similar genes in Helicobacter felis, Helicobacter canis, Helicobacter bilis, Helicobacter hepaticus and Helicobacter mustelae. Western immunoblots using rabbit antibodies raised against a His-tagged-GGT recombinant protein demonstrated that H. pylori GGT is synthesized in both H. pylori and E. coli as a pro-GGT that is processed into a large and a small subunit. Deletion of a 700 bp fragment within the GGT-encoding gene of a mouse-adapted H. pylori strain (SS1) resulted in mutants that were GGT negative yet grew normally in vitro. These mutants, however, were unable to colonize the gastric mucosa of mice when orally administered alone or together (co-infection) with the parental strain. These results demonstrate that H. pylori GGT activity has an essential role for the establishment of the infection in the mouse model, demonstrating for the first time a physiological role for a bacterial GGT enzyme.

Essential role of Helicobacter pylori gamma-glutamyltranspeptidase for the colonization of the gastric mucosa of mice.

Background and aims Infection due to Helicobacter pylori causes many gastrointestinal diseases including peptic ulcers and gastric carcinoma. Their treatment and prevention depends on the successful eradication of H. pylori. However, even after a well-conducted treatment, H. pylori persists in about 10–30% of patients. Recurrent infections can correspond to relapse or to re-infection and require appropriate medical care. In this study, we explore retrospectively three clinical cases using molecular methods, and propose new guidelines for the diagnosis of recurrence. Material and methods Ten colonies of H. pylori were selected from the primary culture of biopsy samples taken from the antrum and fundus for each patient. The genotype of each isolated colony was determined by analyzing the polymorphism of two housekeeping genes, hspA and glmM. The genome-wide composition of H. pylori strains was studied using in house macro-arrays designed. Results Relapses were demonstrated by the stability of genoty...

Diagnosis of Helicobacter pylori recurrence: relapse or reinfection? Usefulness of molecular tools

Introduction: Buruli ulcer, caused by Mycobacterium ulcerans, is endemic in more than 30 countries worldwide, with Cote d'Ivoire being among the most affected countries. Methodology: We used seven variable number of tandem repeats (VNTR) markers and analyzed 114 samples from 11 Ivorian localities consisting of 33 bacterial strains and 81 clinical samples. Complete data sets at loci 1, 6, 9 and 33 were obtained for 18 of these strains (n = 15) and samples (n = 3) collected in each of the localities. Results: All the strains had allelic profile [3113], corresponding to the previously described Atlantic Africa genotype. Conclusion: Sequencing of PCR products at all loci showed no variation in sequence or repeat number, underlining the genetic monomorphism of M. ulcerans in Cote d'Ivoire.

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Jean Michel Thiberge

Papers

Chikungunya virus, southeastern France.

Essential role of Helicobacter pylori gamma-glutamyltranspeptidase for the colonization of the gastric mucosa of mice.

Diagnosis of Helicobacter pylori recurrence: relapse or reinfection? Usefulness of molecular tools

Multilocus VNTR analysis of Mycobacterium ulcerans strains isolated in Côte d'Ivoire.