Bioaccumulation and Depletion of the Antibiotic Sulfadiazine 14C in Lambari (Astyanax bimaculatus).

Antibiotics are present in the environment, primarily due to their release through wastewater treatment plants, agricultural practices, and improper disposal of unused medications. In the environment, these drugs can be bioaccumulated by organisms and transferred along the food chain. This is a problem when considering the consumption of fish meat. In the United States, legislation stipulates that the maximum residue limit for sulfadiazine (SDZ) should not exceed 100 µg kg-1. Lambari fishes have potential economic importance in aquaculture, as they are relatively easy to breed and can be raised in small-scale operations. Finally, studying the biology and ecology of lambari could provide valuable information about freshwater ecosystems and their inhabitants. The current work aimed to measure the bioaccumulation and depletion of the antibiotic SDZ 14C in lambari (Astyanax bimaculatus). For this purpose, the tests were divided into two stages; seven days of exposure and seven days of depletion, where one fish was randomly selected and sampled every day. In the exposure phase, the fish were fed the medicated feed three times a day at a concentration of 2.5 mg·g-1. The control fish were fed uncontaminated feed. For the depletion phase, the remaining lambari were transferred to clean tanks and fed uncontaminated feed three times a day. The fish samples were burned in the Oxidizer and the reading of radioactivity was performed in a liquid scintillation spectrometer. It is worth noting that on day 7 and day 14, the water in the aquariums was filtered through filter paper to collect the metabolic excrement. SDZ concentrations increased over the days and accumulation occurred in the fish, with day seven presenting the maximum accumulation value of 91.7 ng·g-1 due to feeding uptake. After the depletion phase on day 13, the value found was 0.83 ng·g-1. The bioconcentration factor calculated was 20 L·kg-1. After the bioaccumulation period, the concentrations of SDZ in the water and excreta were 4.5 µg·L-1 and 363.5 ng·g-1, respectively. In the depletion period, the concentrations in the water and excreta were 0.01 µg·L-1 and 5.96 ng·g-1, respectively. These results imply that there was little SDZ bioaccumulation in the fish, but that it was distributed in larger amounts in the water. This is due to the physicochemical properties of the molecule with the low Log P value. Regarding the maximum residue limit, the value was below the established value. This study contributes to understanding SDZ dynamics in an aquatic species native to Brazil.

In vitro anthelmintic activity of Euphorbia forskalii J. Gay aqueous extracts evaluation on different life stages of Haemonchus contortus.

The use of medicinal plants in the control of gastrointestinal parasitosis is a promising solution for improving the productivity of sheep flocks. In order to evaluate the anthelmintic activity of Euphorbia forskallii, in vitro bioassays were performed on three life stages of Haemonchus contortus. Five aqueous extracts concentrations namely 10 mg/mL; 5 mg/mL; 2.5 mg/mL; 1.25 mg/mL and 0.62 mg/mL were used for adult worm mortality tests. Egg hatch inhibition and L3 larval migration inhibition tests were studied at 5 mg/mL; 2.5 mg/mL; 1.25 mg/mL; 0.62 mg/mL and 0.31 mg/mL. A negative control PBS and a positive control levamisole 2.5 mg/mL were established for each test. A phytochemical screening was performed to determine the presence of some secondary metabolites. The results obtained showed the presence of total polyphenols, total flavonoids and condensed tannins within the aqueous extracts of E. forskalii. A high and significant (P < 0.05) morality rate compared to the negative control with an LC50 of 2.30 mg/mL was obtained. Inhibition of egg hatch and larval migration were high and significant (p < 0.05) compared to the negative control. There was an IC50 of 1.03 mg/mL and 0.92 mg/mL respectively for inhibition of egg hatching and L3 larval migration. The present study revealed the in vitro anthelmintic activity of E. forskalii aqueous extracts and allows us to consider in perspective complementary studies to confirm this activity.

Dog ownership, demographics, owners' knowledge of rabies, and factors associated with canine rabies vaccination in urban and rural areas of Dedougou, Burkina Faso.

Rabies is a prioritized zoonotic disease in Burkina Faso and is known as a major zoonotic disease with high public health importance. This investigation was conducted to assess community knowledge, dog ecology and demographics, and factors associated with dog vaccination against rabies in the urban and rural areas of Dedougou. Three hundred and sixteen (316) dog-owning households were surveyed in the rural and urban areas of Dedougou using a semi-structured questionnaire. Among participants, 55.7% lived in rural area, and 59.8% were farmers. Only 34.5% of participants had satisfactory knowledge of rabies. About 22% were aware of the required age of dogs' primo vaccination against rabies while 55.7% knew the frequency of booster vaccination. Participants living in households with less than five persons were significantly more likely to be aware of rabies than those living in households with the higher number of persons (P<0.05). Participants who were aware of rabies were more likely to vaccinate their dogs compared to those who were not aware of rabies (P<0.05). In total, 2930 persons were recorded in visited households with 60.6% from rural area, and an average household size of 9.27 persons. Three hundred and thirty seven dogs were found in surveyed households' and 54.9% were from rural area. In overall, a dog per human ratio of 1:8.7 was determinated. Regarding dog ownership practices, the majority of respondents reported that they provided their dogs with water (84.5%) and food (84.8%). This research reported supplementary data on dog ecology and rabies, which could be useful for rabies control planning in Burkina Faso.