Characterization and phylogenetic diversity of Allorhizobium vitis isolated from grapevine in Morocco.

AIMS: Crown gall, a phytobacteriosis characterized by the formation of tumours on plant roots was observed in recently planted vineyards of the Meknes region (Morocco). The objective of this research was to analyse the diversity of pathogenic agrobacteria isolated from grapevine in Morocco. METHODS AND RESULTS: Eighty-two isolates from 11 affected vineyards were characterized by recA sequencing and were found to belong to Agrobacterium tumefaciens genomospecies G1, G4 or G7, Rhizobium rhizogenes, and to Allorhizobium vitis. Only the All. vitis isolates appeared to be pathogenic on tomato and multilocus sequence analysis phylogenetic analyses revealed a weak genetic diversity, with the definition of only four genomic groups. Definition of the All. vitis genomic groups correlated with specific pathogenic traits: indeed, genomic groups differed with respect to the severity of hypersensitive response symptoms on tobacco leaves, the intensity of necrotic response on grapevine explants and opine profiles. Both vitopine and octopine were detected by UHPLC in tumours induced by isolates of three genomic groups, an opine signature scarcely ever reported. CONCLUSIONS: Allorhizobium vitis is the only causative agent of crown gall on grape in Morocco, pathogenic isolates can be separated into four genomic groups. SIGNIFICANCE AND IMPACT OF THE STUDY: This study of recently crown-gall-infested vineyards demonstrated that All. vitis is the only causative agent and revealed the presence of nonpathogenic Agrobacterium strain within tumours. Moreover, as the genetic diversity of the All. vitis isolates is relatively narrow, this study lays the basis for further analyses on the evolution of the disease, on the dissemination of the pTi and more globally on the fate of the different genomic groups in this newly colonized environment.

Spatial multi-criteria decision analysis for modelling suitable habitats of Ornithodoros soft ticks in the Western Palearctic region.

Ticks are economically and medically important ectoparasites due to the injuries inflicted through their bite, and their ability to transmit pathogens to humans, livestock, and wildlife. Whereas hard ticks have been intensively studied, little is known about soft ticks, even though they can also transmit pathogens, including African Swine Fever Virus (ASFV) affecting domestic and wild suids or Borrelia bacteria causing tick-borne relapsing fever (TBRF) in humans. We thus developed a regional model to identify suitable spatial areas for a community of nine Ornithodoros tick species (O. erraticus, O. sonrai, O. alactagalis, O. nereensis, O. tholozani, O. papillipes, O. tartakovskyi, O. asperus, O. verrucosus), which may be of medical and veterinary importance in the Western Palearctic region. Multi-Criteria Decision Analysis was used due to the relative scarcity of high-quality occurrence data. After an in-depth literature review on the ecological requirements of the selected tick community, five climate-related factors appeared critical for feeding activity and tick development: (i) a spring temperature exceeding 10°C to induce the end of winter soft tick quiescent period, (ii) a three-months summer temperature above 20°C to allow tick physiological activities, (iii) annual precipitation ranging from 60mm to 750mm and, in very arid areas, (iv) dry seasons interrupted by small rain showers to maintain minimum moisture inside their habitat along the year or (v) residual water provided by perennial rivers near habitats. We deliberately chose not to include biological factors such as host availability or vegetation patterns. A sensitivity analysis was done by performing multiple runs of the model altering the environmental variables, their suitability function, and their attributed weights. To validate the models, we used 355 occurrence data points, complemented by random points within sampled ecoregions. All models indicated suitable areas in the Mediterranean Basin and semi-desert areas in South-West and Central Asia. Most variability between models was observed along northern and southern edges of highly suitable areas. The predictions featured a relatively good accuracy with an average Area Under Curve (AUC) of 0.779. These first models provide a useful tool for estimating the global distribution of Ornithodoros ticks and targeting their surveillance in the Western Palearctic region.

Cirugía profiláctica en cáncer medular de tiroides hereditario / Prophylactic surgery in hereditary medullary thyroid cancer

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética en algunos cánceres como manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el cáncer medular de tiroides hereditario. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información sobre el cáncer medular de tiroides hereditario. Resultados: Los estudios revisados demuestran que la tiroidectomía profiláctica con resección linfática cervical representa el único tratamiento eficaz en el caso del cáncer medular de tiroides hereditario. Conclusiones: La cirugía profiláctica ha demostrado una importante disminución del riesgo de cáncer de tiroides y se considera una conducta de rigor en portadores del gen RET en el cáncer medular de tiroides.

Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for some cancers, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on hereditary Medullary Thyroid Cancer. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on hereditary Medullary Thyroid Cancer. Results: This research shows that prophylactic Thyroidectomy with cervical lymph node resection is the only effective and curative treatment for hereditary Medullary Thyroid Cancer. Conclusions: Prophylactic surgery has proof an important role decreasing the risk on Hereditary Thyroid cancer Syndrome and in RET carriers surgery is considered a must.

A comparative test of ixodid tick identification by a network of European researchers.

This study reports the results of a comparative test of identification of ticks occurring in Western Europe and Northern Africa. A total of 14 laboratories were voluntarily enrolled in the test. Each participant received between 22 and 25 specimens of adult and nymphal ticks of 11 species: Dermacentor marginatus, D. reticulatus, Haemaphysalis punctata, Hyalomma lusitanicum, Hy. marginatum, Ixodes ricinus, I. hexagonus, Rhipicephalus annulatus, R. bursa, R. rossicus, and/or R. sanguineus s.l. Ticks were morphologically identified by three of the co-authors and the identification confirmed by a fourth co-author who used molecular methods based on several genes. Then ticks were randomly selected and blindly distributed among participants, together with a questionnaire. Only specimens collected while questing and, if possible, in the same survey, were circulated. Because of the random nature of the test, a participant could receive several specimens of the same species. Species in the different genera had variable misidentification rates (MR) of 7% (Dermacentor), 14% (Ixodes), 19% (Haemaphysalis), 36% (Hyalomma), and 54% (Rhipicephalus). Within genera, the MR was also variable ranging from 5.4% for I. ricinus or 7.4% for D. marginatus or D. reticulatus to 100% for R. rossicus. The test provided a total misidentification rate of 29.6% of the species of ticks. There are no significant differences in MR according to the sex of the tick. Participants were requested to perform a second round of identifications on the same set of ticks, using only purposely prepared keys (without illustrations), circulated to the enrolled participants, including 2 species of the genus Dermacentor, 8 of Haemaphysalis, 10 of Hyalomma, 23 of Ixodes, and 6 of Rhipicephalus. The average MR in the second round was 28%: 0% (Dermacentor), 33% (Haemaphysalis), 30% (Hyalomma) 18% (Ixodes), and 50% (Rhipicephalus). Species which are not reported in the countries of a participating laboratory had always highest MR, i.e. purely Mediterranean species had highest MR by laboratories in Central and Northern Europe. Participants expressed their concerns about a correct identification for almost 50% of the ticks of the genera Hyalomma and Rhipicephalus. The results revealed less than total confidence in identifying the most prominent species of ticks in the Western Palearctic, and underpin the need for reference libraries for specialists involved in this task. Results also showed that a combination of certain genes may adequately identify the target species of ticks.

Cirugía profiláctica en síndrome de cáncer hereditario de mama / Prophylactic surgery in breast hereditary cancer syndrome

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética a desarrollar cáncer de mama, una manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el síndrome de cáncer hereditario de mama. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información del síndrome de cáncer hereditario de mama. Resultados: Los estudios revisados demuestran que la mastectomía bilateral profiláctica (MBP) disminuye en un 90% el riesgo de desarrollar cáncer de mama en las mujeres portadoras de BRCA1 o BRCA2. En cuanto a la salpingooferectomía (SO), reduciría entre un 50-56% el riesgo de cáncer de mama dependiendo de la mutación a la que se asocie. Conclusiones: La cirugía profiláctica ha demostrado importante disminución del riesgo de cáncer de mama, por lo que su uso es recomendado al hallazgo de las mutaciones BRCA1 y BRCA2.

Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for breast cancer, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on Hereditary Breast cancer Syndrome. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on Hereditary Breast cancer Syndrome. Results: This research shows that prophylactic bilateral mastectomy (PBM) decreases 90% risk of developing breast cancer in BRCA1 and BRCA2 carriers. On the other hand, Salpyngo-oophoferectomy (SO) technique decreases around 53% chances of breast cancer, depending on the associated mutation. Conclusion: Prophylactic surgery has shown an important role decreasing the risk on Hereditary Breast cancer Syndrome. So on, in cases of BRCA1 and BRCA2 carriers we suggest to perform prophylactic surgery.

Daño hepático agudo inducido por claritromicina. A propósito de un caso / Acute liver injury induced by clarithromycin, case report

Introducción: El daño hepático por fármacos es una lesión secundaria al uso de medicamentos. Posee una baja incidencia, representando la causa más común de muerte por falla hepática aguda. Es importante el diagnóstico y tratamiento precoz para evitar resultados desfavorables. Presentación del caso: Mujer de 73 años, con antecedentes de Hipertensión arterial en tratamiento, colecistectomizada; cursó neumonía adquirida en la comunidad de presentación atípica en tratamiento con claritromicina 500mg/12 horas y al cuarto día de tratamiento presentó ictericia, coluria, hipocolia y astenia. Al examen físico presentó dolor a palpación en hemiabdomen derecho y hepatomegalia. Los exámenes en urgencias mostraron una marcada alteración de las pruebas hepáticas, con leucocitos de 9.020/mm3 y 8% de eosinófilos. Se solicitó ecotomografía abdominal que no evidenció obstrucción de vía biliar. Durante la hospitalización se descartó serología para Virus Hepatitis A, B, C, Epstein Barr, Citomegalovirus y Virus de la Inmunodeficiancia Humana (VIH), junto con un perfil inmunológico no patológico. Se complementó con colangioresonancia que no evidenció obstrucción de la vía biliar, por lo que se indicó biopsia hepática que concluyó "daño hepático secundario a fármacos''. Se suspendió claritromicina, evolucionando favorablemente dándose de alta al séptimo día. Discusión: La claritromicina es un antibiótico usado ampliamente para tratar las infecciones bacterianas, sin embargo, es capaz de inducir daño hepático. El diagnóstico del daño hepático por fármacos es difícil, requiriéndose alto índice de sospecha, en donde las manifestaciones clínicas, la eosinofilia y el descarte de otras patologías son fundamentales para plantear el diagnóstico.

Introduction: Drug induced liver injury (DILI), is a drug hepatotoxicity, with low incidence. However represents the most common cause of death secondary to acute liver failure. Assertive diagnosis and early treatment is important to avoid adverse results. Case report: A 73-year-old woman, with arterial hypertension and cholecystectomy, who suffered community acquired pneumonia with atypical presentation, was treated with clarithromycin 500 mg twice a day. She manifested jaundice, choluria, hipocholia and fatigue after the fourth day in treatment. Additional, physical examination: at palpation showed right and upper abdominal pain, and hepatomegaly. During the emergency room, laboratory tests showed significant alterations in liver function. Total leukocyte count 9020 with 8% eosinophils. Abdominal ultrasound was negative for biliary obstruction. During hospitalization, markers for autoimmune liver disease were non pathological, and viral serologies (Hepatitis A, B, C viruses, Epstein Barr, Cytomegalovirus and Human immunodeficiency virus) were negative. Biliary obstruction was negative according Magnetic resonance cholangiopancreatography. Liver biopsy showed "drug induced liver injury". Clarithromycin was suspended, and the patient achieved clinical improvement and she was discharge at the 7th day. Discussion: Clarithromycin is an antibiotic widely used for several bacterial infections, capable of induced hepatotoxicity. Diagnosis of DILI is difficult, that requires high index of clinical suspicion. Clinical manifestations, eosinophilia and diferential diagnoses are key for an assertive diagnosis

Dermatitis de contacto inducida por henna: Reporte de un caso / Contact dermatitis induced by henna: A case report

La henna es un colorante vegetal ampliamente utilizado para crear tatuajes temporales. Su coloración negra se debe a la adición de parafenilendiamina, potente sensibilizador, conocido como agente causal de dermatitis de contacto por reacciones de hipersensibilidad tipo IV. La frecuencia de dermatitis de contacto secundarias a este compuesto parece ir en aumento, siendo necesario educar a la población en relación a los efectos secundarios a su uso, que en algunos casos pueden ser severos y permanentes.

Henna is a vegetal colorant widely used to create temporary tattoos. Its black color is created by the addition of paraphenylenediamine that is a potent sensitizer agent, known as a cause of type-IV allergic contact dermatitis. The frequency of contact dermatitis secondary to this compound appears to be increasing, being necessary to educate people regarding the secondary effects of its use, which in some cases can be severe and permanent.

Small RNA Deep-Sequencing Analyses Reveal a New Regulator of Virulence in Agrobacterium fabrum C58.

Novel ways of regulating Ti plasmid functions were investigated by studying small RNAs (sRNAs) that are known to act as posttranscriptional regulators in plant pathogenic bacteria. sRNA-seq analyses of Agrobacterium fabrum C58 allowed us to identify 1,108 small transcripts expressed in several growth conditions that could be sRNAs. A quarter of them were confirmed by bioinformatics or by biological experiments. Antisense RNAs represent 24% of the candidates and they are over-represented on the pTi (with 62% of pTi sRNAs), suggesting differences in the regulatory mechanisms between the essential and accessory replicons. Moreover, a large number of these pTi antisense RNAs are transcribed opposite to those genes involved in virulence. Others are 5'- and 3'-untranslated region RNAs and trans-encoded RNAs. We have validated, by rapid amplification of cDNA ends polymerase chain reaction, the transcription of 14 trans-encoded RNAs, among which RNA1111 is expressed from the pTiC58. Its deletion decreased the aggressiveness of A. fabrum C58 on tomatoes, tobaccos, and kalanchoe, suggesting that this sRNA activates virulence. The identification of its putative target mRNAs (6b gene, virC2, virD3, and traA) suggests that this sRNA may coordinate two of the major pTi functions, the infection of plants and its dissemination among bacteria.

Hepatitis alcohólica severa no respondedor a a glucocorticoides: reporte de un caso / Alcoholic hepatitis not responding to corticosteroids: a case report

INTRODUCCIÓN: La hepatitis alcohólica corresponde a un daño inflamatorio agudo sobre un hígado progresivamente dañado por la ingesta excesiva y prolongada de alcohol. Puede presentar ictericia, manifestaciones de alcoholismo crónico e insuficiencia hepática progresiva. PRESENTACIÓN DEL CASO: Varón de 60años con antecedentes de daño hepático crónico secundario a alcoholismo activo, que presentó cuadro de dos semanas de ictericia progresiva, prurito y bradipsiquia, asociado a leucocitosis, hiperbilirrubinemia, y elevación discreta de transaminasas, con predominio de GOT sobre GPT. Hemocultivos, urocultivo y serologías para virus hepatotropos fueron negativos. La ecografía abdominal mostró signos de hepatopatía crónica, sin dilatación de vía biliar. Con una función discriminante de Maddrey de 106 puntos se inició pentoxifilina, evolucionando tórpidamente. Se agregó prednisona durante siete días; se obtiene una puntuación de Lille de 0,99 (no respondedor), suspendiendo los corticoides. Progresó la insuficiencia hepática, con posterior insuficiencia renal aguda, acidosis metabólica, trastornos hidroelectrolíticos y fallecimiento al mes de evolución. DISCUSIÓN: La hepatitis alcohólica posee alta mortalidad. Existen múltiples escalas pronósticas. Los corticoides están indicados en casos severos, sin embargo hasta un 40 por ciento se catalogan como no respondedores. Se requieren nuevos tratamientos para mejorar la supervivencia de estos pacientes.

INTRODUCTION: Alcoholic hepatitis constitutes an acute inflammatory episode due to prolonged alcohol abuse on a previously damaged liver. Clinical features include jaundice, signs of chronic alcoholism and progressive liver failure. CASE REPORT: A 60-yearold male with a history of cirrhosis due to ongoing excessive intake of alcohol presented a two week history of progressive jaundice, pruritus, and bradypsychia. Laboratory tests showed leukocytosis, hyperbilirubinemia and a mild elevation of liver enzymes (GOT over GPT). Blood and urine cultures as well as serological markers for viral hepatitis were negative. Abdominal ultrasound showed signs of chronic liver disease, with no bile duct dilatation. A modified Maddrey’s discriminant function of 106 was determinant on starting therapy with pentoxifyline. However, patient’s status deteriorated. Prednisone was added to the treatment but seven days later, the patient was categorized as a non-responder (Lille score of 0.99), so the glucocorticoids were suspended. The patient’s liver failure progressed, after which renal failure, metabolic acidosis and electrolytic abnormalities developed; that led to his death after one month from admission. DISCUSSION: Alcoholic hepatitis requires prompt diagnosis and treatment, due to its high death rate. There are various prognostic scales available, one of which is the modified Maddrey’s discriminant function. The fundamental therapeutic measure is the use of intravenous glucocorticoids; yet up to 40 percent of patients qualify as non-responders.

Rapid and accurate species and genomic species identification and exhaustive population diversity assessment of Agrobacterium spp. using recA-based PCR.

Agrobacteria are common soil bacteria that interact with plants as commensals, plant growth promoting rhizobacteria or alternatively as pathogens. Indigenous agrobacterial populations are composites, generally with several species and/or genomic species and several strains per species. We thus developed a recA-based PCR approach to accurately identify and specifically detect agrobacteria at various taxonomic levels. Specific primers were designed for all species and/or genomic species of Agrobacterium presently known, including 11 genomic species of the Agrobacterium tumefaciens complex (G1-G9, G13 and G14, among which only G2, G4, G8 and G14 still received a Latin epithet: pusense, radiobacter, fabrum and nepotum, respectively), A. larrymoorei, A. rubi, R. skierniewicense, A. sp. 1650, and A. vitis, and for the close relative Allorhizobium undicola. Specific primers were also designed for superior taxa, Agrobacterium spp. and Rhizobiaceace. Primer specificities were assessed with target and non-target pure culture DNAs as well as with DNAs extracted from composite agrobacterial communities. In addition, we showed that the amplicon cloning-sequencing approach used with Agrobacterium-specific or Rhizobiaceae-specific primers is a way to assess the agrobacterial diversity of an indigenous agrobacterial population. Hence, the agrobacterium-specific primers designed in the present study enabled the first accurate and rapid identification of all species and/or genomic species of Agrobacterium, as well as their direct detection in environmental samples.

Review of the sylvatic cycle of African swine fever in sub-Saharan Africa and the Indian ocean.

African swine fever (ASF) is a major limiting factor for pig production in most of the countries in Sub-Saharan Africa and the Indian Ocean. In the absence of vaccine, a good understanding of the ecology and epidemiology of the disease is fundamental to implement effective control measures. In selected countries of Southern and East Africa, the association between Ornithodoros moubata ticks and warthogs has been described in detail in the literature. However, for many other countries in the region, information related to the sylvatic cycle is lacking or incomplete. In West African countries, for instance, the role of wild pigs in the epidemiology of ASF has never been demonstrated and the existence and potential impact of a sylvatic cycle involving an association between soft ticks and warthogs is questionable. In other countries, other wild pig species such as the bushpigs (Potamochoerus spp.) can also be asymptomatically infected by the virus but their role in the epidemiology of the disease is unclear and might differ according to geographic regions. In addition, the methods and techniques required to study the role of wild hosts in ASF virus (ASFV) epidemiology and ecology are very specific and differ from the more traditional methods to study domestic pigs or other tick species. The aim of this review is (i) to provide a descriptive list of the methodologies implemented to study the role of wild hosts in African swine fever, (ii) to compile the available knowledge about the sylvatic cycle of ASFV in different regions of Sub-Saharan Africa and the Indian Ocean in addition to the one that has been described for East and Southern Africa, and (iii) to discuss current methodologies and available knowledge in order to identify new orientations for further field and experimental surveys.

Assessment of interactions between African swine fever virus, bushpigs (Potamochoerus larvatus), Ornithodoros ticks and domestic pigs in north-western Madagascar.

Since its introduction in Madagascar in 1998, African swine fever (ASF) has severely affected national pig production and persists as a common disease in that country. Two of its natural hosts in the African continent, the bushpig (Potamochoerus larvatus) and tick vectors of the Ornithodoros moubata complex, are reported in west and central regions of the island. However, their role in the maintenance and transmission of the virus has been insufficiently studied. In this work, we tried to assess their potential role in the epidemiology of the disease in Madagascar, by assessing the levels of interaction between (i) ASF virus (ASFV) and bushpigs and (ii) between soft ticks and domestic and wild suids in north-western Madagascar. Twenty-seven sera and 35 tissue samples from bushpigs were collected and analysed for the presence of anti-ASF antibodies and viral DNA. In addition, the sera from 27 bushpigs and 126 domestic pigs were analysed with an ELISA test for the detection of antibodies against salivary antigens from Ornithodoros ticks. No circulation of ASFV or anti-ASFV antibodies nor anti-tick antibodies were detected in bushpigs. However, seven of the domestic pig sera (5.6% of the total sample population) were antibody positive for O. moubata antigens. The probability of freedom from ASFV in the bushpig population using Bayesian statistical methods ranged between 73% and 84%. The probabilities of absence of anti-tick antibodies in domestic and wild pigs were estimated at 63% and 71%, respectively. These preliminary results suggest that bushpigs are unlikely to play a significant role in the maintenance and transmission of ASFV in Madagascar. Nevertheless, further ASFV surveys are needed on that species to confirm this assumption. In addition, the presence of antibodies against O. moubata in domestic pigs suggests that soft ticks may be able to maintain ASFV within a domestic pig cycle in areas of Madagascar where they remain present.

Population structuring of the tsetse Glossina tachinoides resulting from landscape fragmentation in the Mouhoun River basin, Burkina Faso.

The impact of landscape fragmentation resulting from human- and climate-mediated factors on the structure of a population of Glossina tachinoides Westwood (Diptera: Glossinidae) in the Mouhoun River basin, Burkina Faso, was investigated. Allele frequencies at five microsatellite loci were compared in four populations. The average distance between samples was 72 km. The sampling points traversed an ecological cline in terms of rainfall and riverine forest ecotype, along a river loop that enlarged from upstream to downstream. Microsatellite DNA demonstrated no structuring among the groups studied (F(ST) = 0.015, P = 0.07), which is contrary to findings pertaining to Glossina palpalis gambiensis Vanderplank in the same geographical area. The populations of G. tachinoides showed complete panmixia (F(IS) = 0, P = 0.5 for the whole sample) and no genetic differentiation among populations or global positioning system trap locations. This is in line with the results of dispersal studies which indicated higher diffusion coefficients for G. tachinoides than for G. p. gambiensis. The impact of these findings is discussed within the framework of control campaigns currently promoted by the Pan African Tsetse and Trypanosomosis Eradication Campaign.

Biological and ecological characteristics of soft ticks (Ixodida: Argasidae) and their impact for predicting tick and associated disease distribution.

As evidence of global changes is accumulating, scientists are challenged to detect distribution changes of vectors, reservoirs and pathogens caused by anthropogenic and/or environmental changes. Statistical and mathematical distribution models are emerging for ixodid hard ticks whereas no prediction has ever been developed for argasid ones. These last organisms remain unknown and under-reported; they differ from hard ticks by many structural, biological and ecological properties, which complicate direct adaptation of hard tick models. However, investigations on bibliographic resources concerning these ticks suggest that distribution modelling based on natural niche concept and using environmental factors especially climate is also possible, bearing in mind the scale of prediction and their specificities including their nidicolous lifestyle, an indiscriminate host feeding and a short bloodmeal duration, as well as a flexible development cycle through diapause periods.

Population sizes and dispersal pattern of tsetse flies: rolling on the river?

The West African trypanosomoses are mostly transmitted by riverine species of tsetse fly. In this study, we estimate the dispersal and population size of tsetse populations located along the Mouhoun river in Burkina Faso where tsetse habitats are experiencing increasing fragmentation caused by human encroachment. Dispersal estimated through direct (mark and recapture) and indirect (genetic isolation by distance) methods appeared consistent with one another. In these fragmented landscapes, tsetse flies displayed localized, small subpopulations with relatively short effective dispersal. We discuss how such information is crucial for designing optimal strategies for eliminating this threat. To estimate ecological parameters of wild animal populations, the genetic measures are both a cost- and time-effective alternative to mark-release-recapture. They can be applied to other vector-borne diseases of medical and/or economic importance.

Molecular divergences of the Ornithodoros sonrai soft tick species, a vector of human relapsing fever in West Africa.

The soft tick Ornithodoros sonrai is recognized as the only vector of Borrelia crocidurae causing human relapsing fever in West Africa. Its determination has been exclusively based on morphological features, geographical distribution and vector competence. Some ambiguities persist in its systematics and may cause misunderstanding about West African human relapsing fevers epidemiology. By amplifying and aligning 16S and 18S rDNA genes in O. sonrai specimens collected from 14 distinct sites in Senegal and Mauritania, we showed the existence of four genetically different subgroups that were morphologically and ecologically identified as belonging to the same species. Within O. sonrai, intraspecific polymorphism was high (pairwise divergence from 0.2% to 16.4%). In all cases, these four subgroups formed a monophyletic clade sharing a common ancestor with East African soft ticks that transmit Borrelia duttoni human relapsing fever. From amplification of the flagellin gene of B. crocidurae we verified that all subgroups of O. sonrai were infected by B. crocidurae and may constitute vectors for this pathogen. All flagellin sequences were identical, refuting the hypothesis suggesting parallel evolution between O. sonrai and B. crocidurae. However, differences in infection rates were significant, suggesting different vector competences between subgroups of O. sonrai.

An image-based computational model of oscillatory flow in the proximal part of tracheobronchial trees.

A computational model of an oscillatory laminar flow of an incompressible Newtonian fluid has been carried out in the proximal part of human tracheobronchial trees, either normal or with a strongly stenosed right main bronchus. After acquisition with a multislice spiral CT, the thoracic images are processed to reconstruct the geometry of the trachea and the first six bronchus generations and to virtually travel inside this duct network. The facetisation associated with the 3D reconstruction of the tracheobronchial tree is improved to get a computation-adapted surface triangulation, which leads to a volumic mesh composed of tetrahedra. The Navier-Stokes equations associated with the classical boundary conditions and different values of the flow dimensionless parameters are solved using the finite element method. The airways are supposed to be rigid during rest breathing. The flow distribution among the set of bronchi is determined during the respiratory cycle. Cycle reproducibility and mesh size effects on the numerical results are examined. Helpful qualitative data are provided rather than accurate quantitative results in the context of multimodelling, from image processing to numerical simulations.

[Recommendations in the use of portal images]. / Recommandations pour l'utilisation des images de contrôle.

Technical radiotherapy progress drive the practices towards increasingly more precise irradiations. The recent developments of the various imaging methods and specialized software made more controls possible. The fields of investigations relate to the quality assurance of the irradiation, the reproducibility of positioning, the movements evaluations and real time dosimetry. Radiotherapy finds, in the images exploitation, a strong potential in improving quality treatments, however it is conditioned by the implementation of ambitious programs, time consuming, but essential to grant the precision of virtual simulations and the daily practice. If all the existing technical devices and software offer higher tools than the current practices, the recommendations can be limited to the insurance of a sufficient precision and reproducibility of the whole treatments. It is thus fundamental to be able to filter the errors, the systematic deviations and to control the statistics of positioning and movements. Each radiotherapy department must apply an adapted program to each site and exploit the imaging chain to maintain its results.

Epidemiological processes involved in the emergence of vector-borne diseases: West Nile fever, Rift Valley fever, Japanese encephalitis and Crimean-Congo haemorrhagic fever.

Over the past few decades, the geographical distribution of arthropod-borne zoonoses has dramatically expanded. The influence of human-induced or ecological changes on the risk of disease outbreaks is undeniable. However, few hypotheses have been proposed which address the re-emergence of these diseases, the spread of these viruses to previously uninfected areas and their establishment therein. Host and vector movements play an important role in the dissemination of pathogens, and the ability of these diseases to colonise previously uninfected areas may be explained by the diversity of hosts and vectors, the presence of favourable ecological conditions, and the successful adaptations of vectors or pathogens to new ecosystems. The objective of this paper is to describe the epidemiological processes of the vector-borne diseases Rift Valley fever, West Nile fever, Japanese encephalitis and Crimean-Congo haemorrhagic fever.

Recognition of tRNAs by Methionyl-tRNA transformylase from mammalian mitochondria.

Protein synthesis involves two methionine-isoaccepting tRNAs, an initiator and an elongator. In eubacteria, mitochondria, and chloroplasts, the addition of a formyl group gives its full functional identity to initiator Met-tRNA(Met). In Escherichia coli, it has been shown that the specific action of methionyl-tRNA transformylase on Met-tRNA(f)(Met) mainly involves a set of nucleotides in the acceptor stem, particularly a C(1)A(72) mismatch. In animal mitochondria, only one tRNA(Met) species has yet been described. It is admitted that this species can engage itself either in initiation or elongation of translation, depending on the presence or absence of a formyl group. In the present study, we searched for the identity elements of tRNA(Met) that govern its formylation by bovine mitochondrial transformylase. The main conclusion is that the mitochondrial formylase preferentially recognizes the methionyl moiety of its tRNA substrate. Moreover, the relatively small importance of the tRNA acceptor stem in the recognition process accounts for the protection against formylation of the mitochondrial tRNAs that share with tRNA(Met) an A(1)U(72) motif.