RECOVERY OF THIRD-STAGE LARVAE OF ANGUILLICOLA CRASSUS (NEMATODA : DRACUNCULOIDEA) FROM THE FLESH OF FISHES : ASSESSMENT OF A DIGESTIVE MEDIUM AS A TOOL FOR THE STUDY OF FISH PARATENIC HOSTS.

The purpose of this study was to recover third-stage larvae (L3) of Anguillicola crassus alive from the flesh of fishes. Different digestive media have been tested on eel flesh for their efficiency and on living infective third-stage larvae for their harmlessness. The results were : (1) Long-term survival of the L3 larvae was low, but their morphological features were recognizable in each digestion runs. (2) Pepsin concentrations between 2.5 and 40 g/l proved to be without influence on the short-term (2-4 hours) survival of the L3 larvae of A. crassus. The digestion of the eel flesh was more advanced with the most concentrated media, when applied for 12 hours. (3) L3 larvae survived longer at pH 1.8 than 1.5, and digestion appeared to be faster at the upper pH level. (4) L3 larvae survival was much longer at 20°C than at 30°C, but efficiency of the digestion process was poor at the lower temperature. For epidemiological studies, the optimal factors combination has been established at pepsin concentration : 10 g/l, pH : 1.8 and temperature : 20-22°C, particularly when quantitative recovery of L3 larvae and work efficiency were taken into account

Thermoplastic starch and poly(ε-caprolactone) blends: morphology and mechanical properties as a function of relative humidity

International audienc

Fasciola hepatica: The growth and larval productivity of redial generations in Galba truncatula subjected to miracidia differing in their mammalian origin

International audienceExperimental infections of Galba truncatula with 4 isolates of Fasciola hepatica miracidia differing by their mammalian origin (cattle, nutrias, rabbits, or sheep) were carried out to determine if parasite origin had an effect on the number of free rediae, their growth, and their larval productivity in each redia category. The mammalian origin of miracidia had a significant influence on the numbers of free rediae (they were higher in cattle-group snails) and the lengths of rediae (they were lower in rabbit groups). The redia category had also a significant effect on body and pharyngeal measurements. In all groups, the majority of cercariae (55.8–63.2%) were produced by the daughter rediae (R2a rediae) originating from the first mother redia. Compared with the other groups, the mean number of cercariae at day 49 postexposure was twice as high in cattle groups. In contrast, the mean number of daughter rediae produced by each second-appearing mother redia or each R2a redia was higher in the nutria, rabbit, and sheep groups. The mammalian origin of F. hepatica miracidia had an effect on the number of live rediae, their length, and their redial and cercarial productivity

Do agricultural landscape features influence the local abundance of rodents, ticks and their interactions?

International audienc

Do agricultural landscape features influence the local abundance of rodents, ticks and their interactions?

International audienc

Pulsed light inactivation of Bacillus subtilis vegetative cells in suspensions and spices

International audienc

Does agricultural landscape influence rodents and ticks abundances and their interaction?

International audienc

Pilot-Scale Pulsed UV Light Irradiation of Experimentally Infected Raspberries Suppresses Cryptosporidium parvum Infectivity in Immunocompetent Suckling Mice

International audienceCryptosporidium spp., a significant cause of foodborne infection, have been shown to be resistant to most chemical food disinfectant agents and infective for weeks in irrigation waters and stored fresh vegetal produce. Pulsed UV light (PL) has the potential to inactivate Cryptosporidium spp. on surfaces of raw or minimally processed foods or both. The present study aimed to evaluate the efficacy of PL on viability and in vivo infectivity of Cryptosporidium parvum oocysts present on raspberries, a known source of transmission to humans of oocyst-forming apicomplexan pathogens. The skin of each of 20 raspberries was experimentally inoculated with five 10-ll spots of an oocyst suspension containing 6 3 10 7 oocysts per ml (Nouzilly isolate). Raspberries were irradiated by PL flashes (4 J/cm 2 of total fluence). This dose did not affect colorimetric or organoleptic characteristics of fruits. After immunomagnetic separation from raspberries, oocysts were bleached and administered orally to neonatal suckling mice. Seven days after infection, mice were euthanized, and the number of oocysts in the entire small intestine was individually assessed by immunofluorescence flow cytometry. Three of 12 and 12 of 12 inoculated mice that received 10 and 100 oocysts isolated from nonirradiated raspberries, respectively, were found infected. Four of 12 and 2 of 12 inoculated mice that received 10 3 and 10 4 oocysts from irradiated raspberries, respectively, were found infected. Oocyst counts were lower in animals inoculated with 10 3 and 10 4 oocysts from irradiated raspberries (92 6 144 and 38 6 82, respectively) than in animals infected with 100 oocysts from nonirradiated raspberries (35,785 6 66,221, P ¼ 0.008). PL irradiation achieved oocyst reductions of 2 and 3 log for an inoculum of 10 3 and 10 4 oocysts, respectively. The present pilot-scale evaluation suggests that PL is an effective mode of decontamination for raspberries and prompts further applicability studies in industrial contexts