Chiraz Talbi

Institut Pasteur, Lutetia Parisorum, Île-de-France, France

Are you Chiraz Talbi?

Claim your profile

Publications (9)37.09 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: A rhabdovirus was isolated in cell culture inoculated with tissue material from diseased grayling, Thymallus thymallus (L.), originating from a fish farm affected by a mortality episode in Poland. Diagnostics tests showed that the virus was not related to novirhabdoviruses known in Europe, nor to vesiculovirus-like species, except perch rhabdovirus (PRhV) with which it shared moderate serological relations. However, RT-PCR with PRhV probes gave negative results. To identify the virus, a random-priming sequence-independent single primer amplification was adopted. Surprisingly, two of the obtained sequences exhibited a high identity (>99%) with hirame rhabdovirus (HIRRV), a novirhabdovirus usually found in fish in marine Asiatic countries, for instance Japan, China and Korea. The full-length sequence of the phosphoprotein gene (P) demonstrated a higher identity of the present isolate with HIRRV from China compared with the Korean isolate. An identical viral sequence was also found in brown trout, Salmo trutta trutta L., affected by mortalities in a second farm in the same region, after a likely contamination from the grayling farm. To our knowledge, this is the first report of HIRRV in Europe, and in two hosts from fresh water that have not been described before as susceptible species.
    Journal of Fish Diseases 08/2013; DOI:10.1111/jfd.12119 · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in France and support the hypothesis of circulation of these viruses between other hosts and regions within Europe.
    Archives of Virology 09/2011; 156(12):2133-44. DOI:10.1007/s00705-011-1103-z · 2.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: [This corrects the article on p. e1001166 in vol. 6.].
    PLoS Pathogens 01/2011; 7(1). DOI:10.1371/annotation/66c3b26f-7b78-4412-96d0-c960b8d74b50 · 8.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Author Summary At least 15 million doses of anti-rabies post-exposure prophylaxis are administered annually worldwide, and an estimated 55,000 people die of rabies every year. Over 99% of these deaths occur in developing countries, predominantly in Asia and in Africa where rabies is endemic in domestic dogs. Despite the global health burden due to rabies, little is known about the patterns of the spread of dog rabies in these endemic regions. We used recently developed Bayesian analytical methods to unravel the dynamics and determinants of the spatial diffusion of dog rabies viruses in North Africa based on viral genetic data. Our analysis reveals a combination of restricted spread across administrative borders, the occasional long-distance movement of rabies viruses, and a strong fit between spatial spread of the virus and road distances between localities. Together, these data indicate that by transporting dogs, humans have played a key role in the dispersal of a major animal pathogen. Our studies therefore provide essential new information on the transmission dynamics of rabies in Africa, and in doing so will greatly assist in future intervention strategies.
    PLoS Pathogens 10/2010; 6(10):e1001166. DOI:10.1371/journal.ppat.1001166 · 8.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Genetic characterization of 32 canine rabies viruses circulating in Burkina Faso in 2007 identified two clades both belonging to the Africa 2 lineage. Sequence homology data suggest that transboundary spread is the most likely means of introduction, highlighting an evolving epidemiological situation.
    Zoonoses and Public Health 12/2009; 57(7-8):e42-6. DOI:10.1111/j.1863-2378.2009.01291.x · 2.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The burden of rabies in Africa is estimated at 24,000 human deaths year(-1), almost all of which result from infection with dog rabies viruses (RABV). To investigate the evolutionary dynamics of RABV in western and central Africa, 92 isolates sampled from 27 African countries over 29 years were collected and sequenced. This revealed that RABV currently circulating in dogs in this region fell into a single lineage designated 'Africa 2'. A detailed analysis of the phylogeographical structure of this Africa 2 lineage revealed strong population subdivision at the country level, with only limited movement of virus among localities, including a possible east-to-west spread across Africa. In addition, Bayesian coalescent analysis suggested that the Africa 2 lineage was introduced into this region of Africa only recently (probably <200 years ago), in accordance with the timescale of expanding European colonial influence and urbanization, and then spread relatively slowly, perhaps occupying the entire region in a 100 year period.
    Journal of General Virology 04/2009; 90(Pt 4):783-91. DOI:10.1099/vir.0.007765-0 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Author Summary Rhabdoviruses are of considerable socioeconomic importance. For example, rabies virus causes lethal encephalitis resulting in approximately 50,000 human deaths per year. Rhabdoviruses infect cells and propagate despite having small genomes that encode only five multifunctional proteins. One of these, the matrix protein, plays a structural role in virus assembly in addition to modulating the production of host and virus proteins, promoting viral egress from the host cell and modulating cell death. We have solved the 3-dimensional crystal structures of matrix proteins from two distantly related rhabdoviruses: Lagos bat virus and vesicular stomatitis virus. The two proteins have very similar structures despite having dissimilar amino acid sequences. Surprisingly, for both we observe self-association between a pocket on the main globular domain and one extremity of an adjacent molecule in the crystal. Repetition of this interaction gives rise to non-covalent polymers of matrix proteins, adjacent proteins being tethered by a flexible linker. This provides a compelling molecular mechanism for the self-association of matrix molecules required for virus assembly. While the general mode of polymerization is conserved between the two structures, the precise molecular details of the interactions differ, consistent with these matrix proteins binding different cellular factors during infection.
    PLoS Pathogens 01/2009; 4(12):e1000251. DOI:10.1371/journal.ppat.1000251 · 8.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Lyssaviruses are RNA viruses with single-strand, negative-sense genomes responsible for rabies-like diseases in mammals. To date, genomic and evolutionary studies have most often utilized partial genome sequences, particularly of the nucleoprotein and glycoprotein genes, with little consideration of genome-scale evolution. Herein, we report the first genomic and evolutionary analysis using complete genome sequences of all recognised lyssavirus genotypes, including 14 new complete genomes of field isolates from 6 genotypes and one genotype that is completely sequenced for the first time. In doing so we significantly increase the extent of genome sequence data available for these important viruses. Our analysis of these genome sequence data reveals that all lyssaviruses have the same genomic organization. A phylogenetic analysis reveals strong geographical structuring, with the greatest genetic diversity in Africa, and an independent origin for the two known genotypes that infect European bats. We also suggest that multiple genotypes may exist within the diversity of viruses currently classified as 'Lagos Bat'. In sum, we show that rigorous phylogenetic techniques based on full length genome sequence provide the best discriminatory power for genotype classification within the lyssaviruses.
    PLoS ONE 02/2008; 3(4):e2057. DOI:10.1371/journal.pone.0002057 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction Hirame rhabdovirus (HIRRV) is one of the four recognized species within the Novirhabdovirus genus, represented by the type species Infectious Haematopoietic Necrosis (IHNV). HIRRV was first isolated during an outbreak on cultured flounder (Paralichthys olivaceus) and ayu (Plecoglossus altivelis) in Japan (1). It was also found on other marine fish in Asia, such as stone flounder (Kareius bicoloratus) in China (2). Furthermore, it was shown to be pathogenic for a range of salmonids species, including rainbow trout, experimentally challenged in freshwater. The major clinical signs of HIRRV infection were congestion of the gonads, focal hemorrhages of the skeletal muscle and fins and ascitic fluid collection (3). We report the first description of HIRRV in Europe, isolated from grayling and brown trout in a farm in Poland. Materials & methods Thirty adult graylings (Thymallus thymallus) with clinical signs and thirty asymptomatic adult brown trouts (Salmo trutta m. fario) from the same farm in Poland were tested for the presence of novirhabdoviruses by cell culture. Pools of kidney and spleen from a maximum of 10 fish were homogenized. For virus propagation, epithelioma papulosum cyprini (EPC), fathead minnow (FHM), rainbow trout gonad (RTG) and bluegill fry (BF-2) cell lines were inoculated and incubated at 15°C. Cell cultures were collected for virus identification when cytopathic effect (CPE) appeared, usually 4 to 7 d later. Starting from RNA extracted from cell culture supernatant, a random-priming sequence-independent single primer amplification (SISPA) was adopted to search for viral sequences (4). PCR products were cloned and sequenced according to the Sanger method.