Infection of Wildlife by Mycobacterium bovis in France Assessment Through a National Surveillance System, Sylvatub

Mycobacterium bovis infection was first described in free-ranging wildlife in France in 2001, with subsequent detection in hunter-harvested ungulates and badgers in areas where outbreaks of bovine tuberculosis (TB) were also detected in cattle. Increasing concerns regarding TB in wildlife led the French General Directorate for Food (DGAL) and the main institutions involved in animal health and wildlife management, to establish a national surveillance system for TB in free-ranging wildlife. This surveillance system is known as “Sylvatub.” The system coordinates the activities of various national and local partners. The main goal of Sylvatub is to detect and monitor M. bovis infection in wildlife through a combination of passive and active surveillance protocols adapted to the estimated risk level in each area of the country. Event-base surveillance relies on M. bovis identification (molecular detection) (i) in gross lesions detected in hunter-harvested ungulates, (ii) in ungulates that are found dead or dying, and (iii) in road-killed badgers. Additional targeted surveillance in badgers, wild boars and red deer is implemented on samples from trapped or hunted animals in at-risk areas. With the exception of one unexplained case in a wild boar, M. bovis infection in free-living wildlife has always been detected in the vicinity of cattle TB outbreaks with the same genotype of the infectious M. bovis strains. Since 2012, M. bovis was actively monitored in these infected areas and detected mainly in badgers and wild boars with apparent infection rates of 4.57–5.14% and 2.37–3.04%, respectively depending of the diagnostic test used (culture or PCR), the period and according to areas. Sporadic infection has also been detected in red deer and roe deer. This surveillance has demonstrated that M. bovis infection, in different areas of France, involves a multi-host system including cattle and wildlife. However, infection rates are lower than those observed in badgers in the United Kingdom or in wild boars in Spain

Développement d'une PCR en temps réel pour la détection des Brucella et relations avec le genre Ochrobactrum

Le genre Brucella inclut 10 espèces infectant les animaux et accidentellement l homme. Dans le but d améliorer le diagnostic des brucelloses animales, les performances des techniques de PCR conventionne et PCR en temps réel (PCR-TR) ont été comparées en ciblant les gènes bcsp31, per et IS711 (séquence répétée du génome). La PCR-TR se révèle plus rapide et plus sensible, et la cible IS711 offre une meilleure sensibilité. La PCR-TR évaluée sur des prélèvements biologiques d animaux montre une sensibilité diagnostique supérieure en faveur de l IS711. Afin de confirmer la proximité génétique des genres Brucella et Ochrobactrum, nous avons mis en évidence la présence de la séquence BRU-RS (site préférentiel d insertion d IS711) chez Ochrobactrum, cependant la séquence IS711 en est absente. De même les gènes de Brucella codant des protéines membranaires et une protéine périplasmique ont été révélés chez Ochrobactrum, avec toutefois une variabilité antigénique entre les espèces. En conclusion, la présence de la séquence d insertion IS711 est bien spécifique du genre Brucella et représente une cible de choix pour l identification de ces bactéries.The genus Brucella consists of 10 recognized species that infects animals and occasionally humans. In order to improve the direct diagnosis of animal brucellosis, the performances of real-time PCR (PCR-TR) assays using TaqMan® probes and conventional PCR assays were compared by targeting the 3 following specific genes: (i) bcsp31, (ii) per and (iii) the IS711 (repeated sequence of the genome). The PCR-TR is faster and more sensitive, and the IS711 target offers the highest sensitivity. IS711 offers the highest diagnostic sensitivity as evaluated using PCR-TR on biological samples from animals. In order to confirm the genetic proximity between Brucella and Ochrobactrum, we showed the presence of BRU-RS (insertion site of IS711) in Ochrobactrum, however the IS711 sequence was not found. Moreove Brucella genes encoding outer membrane proteins and one periplasmic protein were present in both genus, but displayed antigenic variability among species. In conclusion, the specificity of insertion sequence IS711 in Brucella is confirmed, and the insertion sequence IS711 is therefore a good target for the identification of this genus.LE MANS-BU Sciences (721812109) / SudocSudocFranceF

Pestes porcines : un point sur la surveillance de la PPA en 2014

National audienc