Evidence of new strains of Wolbachia symbiont colonising semiaquatic bugs (Hemiptera: Gerroidea) in mangrove environment of the Lesser Antilles.

Wolbachia Hertig, 1936 is an intracellular bacterial symbiont colonizing many arthropods. Of the studies done on the bacteria present in the superfamily Gerroidea Leach, 1815, no report of Wolbachia infection had yet been made. Thus, we checked the presence of Wolbachia in six Gerroidea species which colonize tropical aquatic environments by PCR using wsp primer set before sequencing and phylogenetic analyses.

Upscaling the Surveillance of Tick-borne Pathogens in the French Caribbean Islands.

Despite the high burden of vector-borne disease in (sub)tropical areas, few information are available regarding the diversity of tick and tick-borne pathogens circulating in the Caribbean. Management and control of vector-borne disease require actual epidemiological data to better assess and anticipate the risk of (re)emergence of tick-borne diseases in the region. To simplify and reduce the costs of such large-scale surveys, we implemented a high-throughput microfluidic real-time PCR system suitable for the screening of the main bacterial and parasitic genera involved in tick-borne disease and potentially circulating in the area.

RNA Viruses of and and Cattle Susceptibility in the French Antilles.

Ticks transmit a wide variety of pathogens including bacteria, parasites and viruses. Over the last decade, numerous novel viruses have been described in arthropods, including ticks, and their characterization has provided new insights into RNA virus diversity and evolution. However, little is known about their ability to infect vertebrates.

Immunomodulatory Effects of Saliva on Bovine Cells: Characterization of Cellular Responses and Identification of Molecular Determinants.

The tropical bont tick, , is a tick species of veterinary importance and is considered as one of major pest of ruminants in Africa and in the Caribbean. It causes direct skin lesions, transmits heartwater, and reactivates bovine dermatophilosis. Tick saliva is reported to affect overall host responses through immunomodulatory and anti-inflammatory molecules, among other bioactive molecules.

Recombination Is a Major Driving Force of Genetic Diversity in the Anaplasmataceae .

The disease, Heartwater, caused by the , represents a major problem for tropical livestock and wild ruminants. Up to now, no effective vaccine has been available due to a limited cross protection of vaccinal strains on field strains and a high genetic diversity of within geographical locations. To address this issue, we inferred the genetic diversity and population structure of 194 isolates circulating worldwide using Multilocus Sequence Typing based on , and .

An in vitro model to assess the immunosuppressive effect of tick saliva on the mobilization of inflammatory monocyte-derived cells.

Tick-borne pathogens cause potent infections. These pathogens benefit from molecules contained in tick saliva that have evolved to modulate host innate and adaptive immune responses. This is called "saliva-activated transmission" and enables tick-borne pathogens to evade host immune responses.

A user-friendly and scalable process to prepare a ready-to-use inactivated vaccine: the example of heartwater in ruminants under tropical conditions.

The use of cheap and thermoresistant vaccines in poor tropical countries for the control of animal diseases is a key issue. Our work aimed at designing and validating a process for the large-scale production of a ready-to-use inactivated vaccine for ruminants. Our model was heartwater caused by the obligate intracellular bacterium Ehrlichia ruminantium (ER).

West Nile virus transmission in sentinel chickens and potential mosquito vectors, Senegal River Delta, 2008-2009.

West Nile virus (WNV) is an arthropod-borne Flavivirus usually transmitted to wild birds by Culex mosquitoes. Humans and horses are susceptible to WNV but are dead-end hosts. WNV is endemic in Senegal, particularly in the Senegal River Delta.

West Nile virus surveillance, Brazil, 2008-2010.

Background: West Nile virus (WNV) is an emergent pathogen that is widely distributed in North and Central America. The recent introduction in South America has focused attention on the spread of WNV across Southern American countries. The transmission network involves mosquitoes, birds, horses and humans.

Efficiency of inactivated vaccines against heartwater in Burkina Faso: impact of Ehrlichia ruminantium genetic diversity.

In order to identify the appropriate strains to use in vaccination trials against heartwater in Burkina Faso, the protective effect of Gardel and Welgevonden strains was assessed against local strains on sheep vaccinated by infection-and-treatment method: Gardel protected significantly against Burkina Faso strains tested (survival rate 59% for immunised sheep vs 13% for control sheep) while Welgevonden did not (survival rate 45% for immunised sheep vs 25% for control sheep). The efficacy of the ISA50 inactivated vaccine, produced under industrial process, was evaluated in sheep during field challenges in two successive years. During year 1, there was a limited protective effect of the Gardel vaccine with 65% of survival rate for the vaccinated group compared to 49% for the control group (N=153, p=0.

Amblyomma variegatum ticks and heartwater on three Caribbean Islands.

Amblyomma variegatum tick infestation, tick infection by Ehrlichia ruminantium (ER), and ER genetic diversity were studied in the Caribbean Islands of Guadeloupe, Marie-Galante, and Antigua between 2003 and 2005. Nested PCR for pCS20 was used to detect ER, while ER strains were characterized by sequencing or by restriction fragment length polymorphism (RFLP) profiles of map-1 PCR products. In 2003 in Guadeloupe, the prevalence of tick-infested herds was 35.

Nested PCR for detection and genotyping of Ehrlichia ruminantium: use in genetic diversity analysis.

Ehrlichia ruminantium, the agent of cowdriosis transmitted by Amblyomma ticks, presents an extensive genetic and antigenic diversity of key importance for vaccine formulation. Two means of nested polymerase chain reaction (PCR) targeting were developed to conduct molecular epidemiology studies in the Caribbean and Africa. The first used a conserved DNA fragment for detection of the pathogen in animals and vectors, and the second relied on the polymorphic map1 gene for genotyping.