Henri Jean Boulouis

Bio: Henri Jean Boulouis is an academic researcher from École nationale vétérinaire d'Alfort. The author has contributed to research in topics: Bartonella & Bartonella Infection. The author has an hindex of 21, co-authored 36 publications receiving 2326 citations. Previous affiliations of Henri Jean Boulouis include University of Paris & Institut national de la recherche agronomique.

Bartonella Spp. in Pets and Effect on Human Health

Abstract: Among the many mammals infected with Bartonella spp., pets represent a large reservoir for human infection because most Bartonella spp. infecting them are zoonotic. Cats are the main reservoir for Bartonella henselae, B. clarridgeiae, and B. koehlerae. Dogs can be infected with B. vinsonii subsp. berkhoffii, B. henselae, B. clarridgeiae, B. washoensis, B. elizabethae, and B. quintana. The role of dogs as an important reservoir of Bartonella spp. is less clear than for cats because domestic dogs are more likely to be accidental hosts, at least in nontropical regions. Nevertheless, dogs are excellent sentinels for human infections because a similar disease spectrum develops in dogs. Transmission of B. henselae by cat fleas is better understood, although new potential vectors (ticks and biting flies) have been identified. We review current knowledge on the etiologic agents, clinical features, and epidemiologic characteristics of these emerging zoonoses.

Factors associated with the rapid emergence of zoonotic Bartonella infections.

Abstract: Within the last 15 years, several bacteria of the genus Bartonella were recognized as zoonotic agents in humans and isolated from various mammalian reservoirs. Based on either isolation of the bacterium or PCR testing, eight Bartonella species or subspecies have been recognized as zoonotic agents, including B. henselae, B. elizabethae, B. grahamii, B. vinsonii subsp. arupensis, B. vinsonii subsp. berkhoffii, B. grahamii, B. washoensis and more recently B. koehlerae. The present manuscript reviews the factors associated with the emergence of these zoonotic pathogens, including better diagnostic tools and methods to identify these fastidious bacteria, host immunosuppression (caused by infectious agents, cancer, aging or induced by immunosuppressive drugs), the interaction of co-infection by several infectious agents that may enhanced the pathogenecity of these bacteria, increased outdoor activity leading to exposure to wildlife reservoirs or vectors, poverty and low income associated with infestation by various ectoparasites, such as body lice and finally the dispersal of Bartonellae around the world. Furthermore, a description of the main epidemiological and clinical features of zoonotic Bartonellae is given. Finally, the main means for diagnosis, treatment and prevention of these diseases are presented.

Transmission of Bartonella henselae by Ixodes ricinus.

Abstract: Bartonella spp. are facultative intracellular bacteria associated with several emerging diseases in humans and animals. B. henselae causes cat-scratch disease and is increasingly associated with several other syndromes, particularly ocular infections and endocarditis. Cats are the main reservoir for B. henselae and the bacteria are transmitted to cats by cat fleas. However, new potential vectors are suspected of transmitting B. henselae, in particular, Ixodes ricinus, the most abundant ixodid tick that bites humans in western Europe. We used a membrane-feeding technique to infect I. ricinus with B. henselae and demonstrate transmission of B. henselae within I. ricinus across developmental stages, migration or multiplication of B. henselae in salivary glands after a second meal, and transmission of viable and infective B. henselae from ticks to blood. These results provide evidence that I. ricinus is a competent vector for B. henselae.

Cat scratch disease and other zoonotic Bartonella infections.

Abstract: Members of the genus Bartonella are maintained in many domesticated and wild animal hosts. Bartonella henselae, the best understood species, infects housecats and other members of the Felidae. Additional species of Bartonella are found in cats, dogs, livestock, rodents, rabbits and other wild and domesticated animals. In immunocompetent humans, B. henselae causes cat scratch disease, which is most often a relatively benign and self-limiting illness. In contrast, B. henselae infections are often severe in immunocompromised individuals, and can be fatal without antibiotic treatment. Other species of Bartonella have also been linked occasionally to human illnesses, with varying levels of evidence for a causative role. The significance of Bartonella spp. as pathogens for animals is currently unclear. The vast majority of infections are asymptomatic, and although these organisms have been implicated occasionally in illnesses, proving a causative role is difficult.

Role of Hippoboscidae Flies as Potential Vectors of Bartonella spp. Infecting Wild and Domestic Ruminants

Abstract: The putative role of biting flies in Bartonella transmission among ruminants was investigated. Amplification of the Bartonella citrate synthase gene from 83 Hippoboscidae was detected in 94% of 48 adult Lipoptena cervi flies, 71% of 17 adult Hippobosca equina flies, 100% of 20 adult Melophagus ovinus flies, and 100% of 10 M. ovinus pupae. Our findings suggest that Hippoboscidae play a role in the transmission of Bartonella among ruminants. The vertical transmission of Bartonella in M. ovinus and the presence of Bartonella DNA in all samples suggest a symbiotic association between Bartonella and M. ovinus.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

BIGSdb: Scalable analysis of bacterial genome variation at the population level

Abstract: The opportunities for bacterial population genomics that are being realised by the application of parallel nucleotide sequencing require novel bioinformatics platforms These must be capable of the storage, retrieval, and analysis of linked phenotypic and genotypic information in an accessible, scalable and computationally efficient manner The Bacterial Isolate Genome Sequence Database (BIGSDB) is a scalable, open source, web-accessible database system that meets these needs, enabling phenotype and sequence data, which can range from a single sequence read to whole genome data, to be efficiently linked for a limitless number of bacterial specimens The system builds on the widely used mlstdbNet software, developed for the storage and distribution of multilocus sequence typing (MLST) data, and incorporates the capacity to define and identify any number of loci and genetic variants at those loci within the stored nucleotide sequences These loci can be further organised into 'schemes' for isolate characterisation or for evolutionary or functional analyses Isolates and loci can be indexed by multiple names and any number of alternative schemes can be accommodated, enabling cross-referencing of different studies and approaches LIMS functionality of the software enables linkage to and organisation of laboratory samples The data are easily linked to external databases and fine-grained authentication of access permits multiple users to participate in community annotation by setting up or contributing to different schemes within the database Some of the applications of BIGSDB are illustrated with the genera Neisseria and Streptococcus The BIGSDB source code and documentation are available at http://pubmlstorg/software/database/bigsdb/ Genomic data can be used to characterise bacterial isolates in many different ways but it can also be efficiently exploited for evolutionary or functional studies BIGSDB represents a freely available resource that will assist the broader community in the elucidation of the structure and function of bacteria by means of a population genomics approach

Rodent-borne diseases and their risks for public health

Abstract: Rodents are the most abundant and diversified order of living mammals in the world. Already since the Middle Ages we know that they can contribute to human disease, as black rats were associated with distribution of plague. However, also in modern times rodents form a threat for public health. In this review article a large number of pathogens that are directly or indirectly transmitted by rodents are described. Moreover, a simplified rodent disease model is discussed.

A comparison of homologous recombination rates in bacteria and archaea.

Abstract: It is a standard practice to test for the signature of homologous recombination in studies examining the genetic diversity of bacterial populations. Although it has emerged that homologous recombination rates can vary widely between species, comparing the results from different studies is made difficult by the diversity of estimation methods used. Here, Multi Locus Sequence Typing (MLST) datasets from a wide variety of bacteria and archaea are analyzed using the ClonalFrame method. This enables a direct comparison between species and allows for a first exploration of the question whether phylogeny or ecology is the primary determinant of homologous recombination rate.