Behavioral Responses in Zebrafish (Danio rerio) Exposed to Heavy Metal and Insecticide Induced Stress

Background: Changes in fish behavior can help identify accidental chemical pollution. Heavy metals and pesticides are two of the most found pollutants to investigate the different behavioral responses of fish to these two types of pollutants exposure. Methods: Real-time computer imaging was utilized to record parameters of fish behaviors, including swimming speed, turning frequency, depth and distance between fish. Deltamethrin and cadmium were 0.015 ppm and 3.5 ppm, respectively. It was conducted for a total period of 180 min. Fish behaviors were recorded with dechlorinated water during the first 60 mins, then deltamethrin and cadmium was introduced to observe behavioral responses of zebrafish during the next 120 mins. Result: As a result of increased swimming activity, the first response of zebrafish is avoidance followed by a changed distribution in the test chamber. The duration of hyperactivity during deltamethrin exposure was lasted 35 minutes larger than Cd exposure and the average swimming depth showed totally different trends with increased from 140 mm to 226 mm during deltamethrin exposure but decreased from 161 to 84 mm during cadmium exposure. It is proved that these different responses do exist under in the two chemicals studied and this may contribute to the development of biological early warning system to separate accidental chemical pollution types.

Assessment of the Viability of SARS-CoV-2 Coronavirus on Various Types of Test Surfaces, as Well as in Drinking and Sea Water

The aim of this study was to determine the dynamics of the residual infectious activity of the SARSCoV-2 virus on various types of surfaces, including banknotes and coins, in samples of drinking dechlorinated water and samples imitating seawater, with a concentration of sodium chloride salts of 0.9 and 3.5 % at a temperature of 24–28 ºC.Materials and methods. The studies were carried out using the SARS-CoV-2 coronavirus strain nCoV/Victoria/1/2020, from the collection of the SSC VB “Vector”, the initial titer being (6.0±0.2) lg TCD50/ml. We used a Vero E6 cell culture from the collection of the SSC VB “Vector” in the form of a 2-day monolayer with a confluence of 95–100 %, grown in 96-well culture plates.Results and conclusions. The SARS-CoV-2 coronavirus is viable in both fresh and sea water, regardless of its salinity, for at least 48 hours, and the degree of preservation of the residual infectious activity of the virus depends on the water temperature: the lower it is, the better the virus is preserved. It was found that at a temperature of 24–28 C, the SARS-CoV-2 coronavirus is able to maintain infectious activity on all types of test surfaces studied for at least 48 hours, while the degree of the residual infectious activity of the virus depends on the type of surface. The virus is best preserved on stainless steel, plastic and glass. It is demonstrated that SARS-CoV-2 virus activity is retained on the surface of paper money and coins for longer than 24 hours. The conducted studies have confirmed the ability of the SARS-CoV-2 coronavirus to maintain its infectious activity in the environment under favorable conditions and, accordingly, to pose an epidemiological threat to the population.

Antibiotic Resistance Patterns of Bacteria Isolated from Dechlorinated Water Samples

Chlorination has been the method of choice for disinfecting water used for drinking purposes. However, some stressed bacteria during chlorination are able to recover and alter the potability of water. This study assessed the recovery of stressed bacteria in dechlorinated water. Ten chlorinated water samples were collected from different points within Ilorin metropolis, Kwara, Nigeria. The samples (100ml) were dechlorinated with 0.1ml of 11.4mM sodium thiosulphate solution. The physicochemical characteristics of the chlorinated water samples were determined while bacteriological analyses were carried out on both chlorinated and dechlorinated water samples. The antibiotic susceptibility pattern of the isolates was determined using disc diffusion method. The physicochemical characteristics of the water samples ranged as follow: pH 7.3-8.4, chloride content 4.37-6.85 mg/l, suspended solids 0.004-0.017 g/100ml, and total hardness 30-72mg/l. The chlorinated water samples had bacterial, total, and faecal coliform counts ranging from 1.0 × 101 – 1.9 × 104cfu/ml, 0 – 480 MPN/100ml, and zero, respectively. The dechlorinated water sample had corresponding counts of 5.4 × 102 – 7.36 × 104cfu/ml, 6 - 1100 MPN/100ml, and 0 – 380 MPN/100ml. A total of eleven bacterial species belonging to the genera Bacillus, Burkholderia, Citrobacter, Enterobacter, Enterococcus, Escherichia, Staphylococcus, Serratia, and Streptococcus were isolated. Not lower than 60% of the bacterial isolates were susceptible to ofloxacin and ciprofloxacin. All the isolates exhibited multiple antibiotic resistances. The antibiotic resistance pattern of an isolate of Citrobacter freundii to cefuroxime, cefixime, and gentamycin changed remarkably and was plasmid-mediated, while that of E. coli and Enterobacter agglomerans remained unchanged to all the antibiotics and was non-plasmid mediated. Chlorination of water at the point of use is recommended. It is concluded that chlorination is essential in order to prevent reactivation of stressed bacteria during distribution and prevent infection by bacteria with high multiple antibiotic resistance index.

In vivo study on the toxic, cytotoxic, and genotoxic potentials of stem bark ethanolic extract of Cenostigma gardnerianum Tul. (Caneleiro)

Many species of medicinal plants have been used as a therapeutic alternative in the treatment of diseases around the world, as well as promoting advances in the production of herbal medicines. However, this use is often done indiscriminately and leads to serious consequences in the body of those who use them. Therefore, studies on the toxic, cytotoxic, and genotoxic potentials of medicinal plant species are necessary for their safe use. Cenostigma gardnerianum Tul, popularly known as Caneleiro or Canela-de-velho, is widely used by the population for its anti-inflammatory, antispassmolytic, antitussive, antifungal properties, among others. The aim of this research was to study and analyze a possible toxicity, cytotoxicity, and genotoxicity of the ethanolic extract from the bark of the stem of Cenostigma gardnerianum Tul. by means of the Allium cepa in vivo bioassay. The extract was divided into four concentrations, divided into groups A, B, C and D, respectively: 0.5mg/ml, 1.0mg/ml, 2.0mg/ml and 5.0mg/ml, in addition to the Negative Control (dechlorinated water), Positive Control (dimethyl sulfoxide) and Blank control (distilled water). The roots were measured for toxicity evaluation, the Mitotic Index (MI) was calculated for cytotoxicity research, and finally micronuclei count was performed to study the genotoxicity of each extract concentration. The low growth of the meristems indicated the presence of toxicity; the mitotic indices found were statistically lower than in the negative control, revealing cytotoxicity; and the high micronucleus count showed the presence of genotoxicity. From the results obtained, it was concluded that the ethanolic extract of the Caneleiro bark presents toxic, cytotoxic, and genotoxic activity, with statistically significant values for concentrations starting from 2mg/ml.

Growth performance of Astyanax altiparanae fed with plant and/or animal lipid sources

The lambari, Astyanax altiparanae, exhibits a great potential for aquaculture due to its omnivory, rapid growth and ease captive production. Despite of fish lipid metabolism being directly related to the dietary lipid consumed, which may lead to changes in fish growth, nothing much have been established regarding the lipid sources that can be applied in A. altiparanae captive production. Thus, this present research was conducted aiming to evaluate the growth performance and whole body composition of A. altiparanae fed with lipid sources of plant and/or animal origins. Were used a Completely Randomized design experiment with five treatments. The treatments consisted of isoproteic and isoenergetic diets, containing the following lipid sources: T1: linseed, chia and sunflower oils; T2: linseed and corn oils; T3: linseed, chia, corn and sunflower oils; T4: sunflower, corn and fish oils; T5: linseed, chia, sunflower, corn oils and bovine fat. Each treatment was replicated six times, where the experimental units consists of 10 fishes (averaged weight: 4.0 + 0.5 g) placed in an aquarium containing 80L of dechlorinated water. Were compared the growth performance parameters among the treatments by applying an one-way analysis of variance (ANOVA) at 5% significance (P < 0.05). The results revealed that both growth performance and whole body composition of A. altiparanae were not affected by the lipid source, which indicate that these fishes can efficiently use both vegetable lipid sources as well as mixtures of vegetable and animal lipid sources without any growth disadvantages.

Molluscicidal activities of Tetrapleura tetraptera fruit extract, Aridanin and their particulate formulations on adult and newly hatched Biomphalaria glabrata snails

The study investigated the molluscicidal activities of chloroform/methanol (1:1) extract of Tetrapleura tetraptera and isolated Aridanin. It also developed useable particulate formulation of chloroform methanol extract and Aridanin and evaluated their molluscicidal activities. This is with a view to providing information on development of useable particulate formulations for the control of snail intermediate hosts of schistosomiasis. The plant material was extracted successively in n-hexane (100%), chloroform (100%), chloroform/methanol (1:1) and methanol (100%) respectively by maceration. Bioactivity-guided fractionation of chloroform methanol extract was performed using column chromatography to isolate the active compound, Aridanin. Particulate formulations of chloroform methanol extract and Aridanin were prepared by emulsion solvent evaporation method. Molluscicidal screening on adult and newly hatched Biomphalaria glabrata snails was evaluated according to WHO protocols. The blank polymer formulation, dechlorinated water and Niclosamide served as controls. The result showed that Aridanin demonstrated the highest molluscicidal activity on adult B. glabrata snails with 24 h- LC50 of 1.61 ppm. The chloroform methanol extract had an LC50 value of 23.00 ppm, while particulate formulation of Aridanin and chloroform methanol extract had LC50 of 13.40 and 170.60 ppm respectively. This study showed that newly hatched B. glabrata snails are less susceptible to molluscicides compared to adult snails (P

INFLUENCE OF LEAD ACETATE IN CONJUNCTION WITH STEARATES ON THE BONE BRAIN AND PERIPHERAL BLOOD OF SUSPICIOUS ANIMALS

In modern conditions, industrial pollution of the environment with lead is quite significant and has an adverse effect on the body. It has pronounced cumulative properties and is accumulated in bones in the form of insoluble tri-phosphorus. However, under the influence of certain conditions, its reserves in the bones become mobile; it transits into the bloodstream and can cause poisoning, even in the sharp form. The aim – to study the effect of lead acetate in the body at sub-toxic doses on the background of drinking water with stearates content. Materials and Methods. To study the influence of low-frequency lead in isolation and in combination with stearates under conditions of a subacute sanitary-toxicological experiment, the animals were divided into four groups of 7 animals each. The group 1 of animals was a control group. The group 2 of animals consumed dechlorinated water from the city water supply (water + AcPb). Animals of the groups 3 and 4 also consumed dechlorinated water from the city water supply, but with an admixture of sodium stearate (group 3 StNa + AcPb) and potassium stearate (group 4 StK + AcPb) at a dose of 1/250 LD50. After a 30-day application of these waters to animals, the groups 2, 3 and 4 were orally administered lead acetate at a dose of 7 mg/100 g of body weight (1/110 LD50). Results and Discussion. As a result of the action of lead acetate in a dose of 70 mg/kg and stearates, there was an increase in the bone marrow of the number of promyelocytes, stem cells, segmental neutrophils of lymphocytes and normocytes. However, the number of myelocytes and metamyelocytes decreased. Lead acetate and stearates caused an increase in the number of rodenuclear neutrophils, eosinophils, monocytes, lymphocytes and a decrease in the number of segmental neutrophils in the blood of experimental animals. Unlike intact animals in the groups 2, 3 and 4, there were observed events of functional failure of the erythrocytes system such as anisocytosis, poikilocytosis and hypochromia. Conclusions. 1. Thus, with the action of lead acetate at a dose of 70 mg/kg in combination with sodium and potassium stearates, there was an increase in the bone marrow of promyelocytes, stabnoid, segmented neutrophils of lymphocytes and normocytes. The number of myelocytes and metamyelocytes decreased. Lead acetate in combination with sodium and potassium stearates caused an increase in the number of stab neutrophils, eosinophils, monocytes, lymphocytes and a decrease in the number of segmented neutrophils in the blood of experimental animals.

Parasites pitched against nature: Pitch Lake water protects guppies (Poecilia reticulata) from microbial and gyrodactylid infections

SUMMARYThe enemy release hypothesis proposes that in parasite depleted habitats, populations will experience relaxed selection and become more susceptible (or less tolerant) to pathogenic infections. Here, we focus on a population of guppies (Poecilia reticulata) that are found in an extreme environment (the Pitch Lake, Trinidad) and examine whether this habitat represents a refuge from parasites. We investigated the efficacy of pitch in preventing microbial infections in Pitch Lake guppies, by exposing them to dechlorinated water, and reducing gyrodactylid infections on non-Pitch Lake guppies by transferring them to Pitch Lake water. We show that (i) natural prevalence of ectoparasites in the Pitch Lake is low compared to reference populations, (ii) Pitch Lake guppies transferred into aquarium water develop microbial infections, and (iii) experimentally infected guppies are cured of their gyrodactylid infections both by natural Pitch Lake water and by dechlorinated water containing solid pitch. These results indicate a role for Pitch Lake water in the defence of guppies from their parasites and suggest that Pitch Lake guppies might have undergone enemy release in this extreme environment. The Pitch Lake provides an ideal ecosystem for studies on immune gene evolution in the absence of parasites and long-term evolutionary implications of hydrocarbon pollution for vertebrates.