Antiplasmodial activity of iron(II) and ruthenium(II) organometallic complexes against Plasmodium falciparum blood parasites

This work reports the in vitro activity against Plasmodium falciparumblood forms (W2 clone, chloroquine-resistant) of tamoxifen-based compounds and their ferrocenyl (ferrocifens) and ruthenocenyl (ruthenocifens) derivatives, as well as their cytotoxicity against HepG2 human hepatoma cells. Surprisingly with these series, results indicate that the biological activity of ruthenocifens is better than that of ferrocifens and other tamoxifen-like compounds. The synthesis of a new metal-based compound is also described. It was shown, for the first time, that ruthenocifens are good antiplasmodial prototypes. Further studies will be conducted aiming at a better understanding of their mechanism of action and at obtaining new compounds with better therapeutic profile.

Do fly parasites of bats and their hosts coevolve?speciation in Trichobius phyllostomae group (Diptera, Streblidae) and their hosts (Chiroptera, Phyllostomidae) suggests that they do not

We examined whether, like many parasite-host systems of coevolution, a group of obligate parasitic bat flies (Trichobius phyllostomae Kessel and related species) cospeciate with their hosts. We first did a cladistic analysis of the T. phyllostomae group and combined that analysis with a phylogenetic hypothesis from the literature for the Stenodermatinae bats. The cladistic analysis included, as outgroups, one species from each morphological group and complex of Trichobius Gervais, and one species from the following genera: Paratrichobius Miranda-Ribeiro, Megistopoda Macquart, Megistapophysys Dick & Wenzel, Neotrichobius Wenzel & Aitken, Speiseria Kessel and Strebla Wiedemann. The cladogram was rooted with a species of Strebla in the subfamily Streblinae. One cladogram was obtained and which found Trichobius to be polyphyletic. The phylogenetic hypothesis as follows: (Paratrichobius, (Neotrichobius, (Megistopoda, Megistapophysis)))) is the sister-group of the phyllostomae group and the following relationships within the ingroup, (((T. vampyropis Wenzel, Trichobius sp. 2) ((T. hispidus Wenzel, T. petersoni Wenzel) ((Trichobius sp. 1 (T. phyllostomae, T. brennani Wenzel))))). When we compared phylogenies through historical association analyses, cospeciation was uncommon, while host-switching was more common and better explained the association between the phyllostomae group and their bat hosts.

Effect of Bacillus sphaericus Neide on Anopheles (Diptera: Culicidae) and associated insect fauna in fish ponds in the Amazon

ABSTRACTWe analyzed the effects of Bacillus sphaericus on Anopheles larvae and on the associated insect fauna in fish farming ponds. Five breeding sites in the peri-urban area of the city of Manaus, AM, Brazil, were studied. Seven samples were collected from each breeding site and B. sphaericus was applied and reapplied after 15 days. The samples were made at 24 h before application, 24 h post-application and 5 and 15 days post-application. We determined abundance, larval reduction and larval density for Anopheles, and abundance, richness, Shannon diversity index and classified according to the functional trophic groups for associated insect fauna. A total of 904 Anopheles larvae were collected and distributed into five species. Density data and larval reduction demonstrated the rapid effect of the biolarvicide 24 h after application. A total of 4874 associated aquatic insects belonging to six orders and 23 families were collected. Regression analysis of diversity and richness indicated that the application of the biolarvicide had no influence on these indices and thus no effect on the associated insect fauna for a period of 30 days. B. sphaericus was found to be highly effective against the larvae of Anopheles, eliminating the larvae in the first days after application, with no effect on the associated insect fauna present in the fish ponds analyzed.

Fish oil replacement by soybean oil in the diet of fat snook juveniles

The objective of this work was to evaluate fish oil replacement by soybean oil in diets, as for the effects on the performance and body composition of juveniles of fat snook (Centropomus parallelus). The experiment was carried out in a randomized block design, with three treatments (lipid sources) and six replicates, in a 60-day period. Fat snook juveniles (24.17±0.28g) were distributed in 18 experimental tanks of 200 L each, equipped with aeration and heating systems, under continuous water renovation (800% per day). Three isoproteic (44% CP) and isoenergetic (4,635 kcal CE kg-1) diets were formulated to comprise three replacement rates (0, 50, and 100%) of fish oil by soybean oil. Biometric analyses were done to evaluate fish performance, and two entire specimens from each replicate were used for body composition analyses. The zootechnical indices of weight gain (38.68±5.41 g), feed conversion (1.38±0.10), and specific growth at 1.70±0.18% weight gain per day were considered satisfactory. Lipid source substitution does not affect the performance and body composition of fat snook juveniles, which suggests that soybean oil can replace fish oil in diet formulation.

Organochlorine pesticides in Piracicaba river basin (São Paulo/Brazil): a survey of sediment, bivalve and fish

The main objective of this paper was to evaluate the level of occurrence of the organochlorine compounds in samples of sediments, bivalves and two fish species collected in the Piracicaba River basin (São Paulo, Brazil). The isomers alpha and gamma of HCH and Heptachlor were most frequently detected in samples of sediments and specimens of bivalve and fish. Therefore, although the levels of these compounds found were not critically high, they are still found in the environment. This fact suggests that they are still being used, despite the fact that the use of these compounds was outlawed more than twenty years ago.

Determination of moisture content and water activity in algae and fish by thermoanalytical techniques

The water content in seafoods is very important since it affects their sensorial quality, microbiological stability, physical characteristics and shelf life. In this study, thermoanalytical techniques were employed to develop a simple and accurate method to determine water content (moisture) by thermogravimetry (TG) and water activity from moisture content values and freezing point depression using differential scanning calorimetry (DSC). The precision of the results suggests that TG is a suitable technique to determine moisture content in biological samples. The average water content values for fish samples of Lutjanus synagris and Ocyurus chrysurus species were 76.4 ± 5.7% and 63.3 ± 3.9%, respectively, while that of Ulva lactuca marine algae species was 76.0 ± 4.4%. The method presented here was also successfully applied to determine water activity in two species of fish and six species of marine algae collected in the Atlantic coastal waters of Bahia, in Brazil. Water activity determined in fish samples ranged from 0.946 - 0.960 and was consistent with values reported in the literature, i.e., 0.9 - 1.0. The water activity values determined in marine algae samples lay within the interval of 0.974 - 0.979.

Crystallographic studies of fish hemoglobins

The present work reports our succesfull experience concerning crystallization of four fish hemoglobins from three Brazilian species of Teleosts: Liposarcus anisitsi, Brycon cephalus and Piaractus mesopotamicus. The data shown here is part of a systematic functional and structural study of fish hemoglobins with the aim of better understanding the outstanding range of functional and structural properties exhibited by these proteins. We also present a reduced sparse-matrix method for crystallization of fish hemoglobins, which can reduce the amount of hemoglobin initially used in the crystallization experiments.

Isosporoid Coccidia (Apicomplexa: Eimeriidae) parasites of tanagers (Passeriformes: Thraupidae) from the Marambaia Island, Brazil

In recent years some coccidian parasites of birds were recorded in Marambaia Island, which is a protected environment with a great biodiversity of birds, mainly tanagers. In this current study Isospora tiesangui, I. sepetibensis, I. ramphoceli, I. navarroi, I. cadimi and I. marambaiensis were identified according to their respective thraupid hosts of the Marambaia Island. These species were characterized with histograms, linear regression and analysis of variance (ANOVA). The main feature of identification was the morphology of the sporocyst, mainly Stieda and substieda bodies, since the morphometry did not provide sufficient differentiation. Besides, Dacnis cayana and Thraupis palmarum were reported as new hosts to I. sepetibensis and I. navarroi respectively.

Molecular characterization of virulence factors in Aeromonas hydrophila obtained from fish

Multiple factors can be involved in the virulence processes of Aeromonas hydrophila. The objective of the present paper was to verify the presence of aerolysin, hidrolipase, elastase and lipase virulence genes through the polymerase chain reaction (PCR) in A. hydrophila isolates obtained from fish of the São Francisco River Valley, and to evaluate virulence according to the presence of these genes in Nile tilapia fingerlings. One hundred and fourteen isolates from the bacteria were used. DNA was heat extracted and PCR undertaken using specific primers described in the literature. For in vivo tests Nile tilapia fingerlings were used. From the PCR tests, negative isolates for all genes tested were selected, positive isolates for two genes (aerolysin and elastase) and positive for the four genes tested. These were inoculated at a concentration of 10(8) UFC/ml into the tilapias, considered as treatments; another group of animals was used as control (with inoculation of saline solution). In all, 12 distinct standards regarding the presence of virulence factors in isolates from A. hydrophila, were observed. Of the 114 isolates analyzed, 100 (87.72%) presented at least one of the virulence factors under study. The virulence factors were widely distributed among the A. hydrophila isolates. Aerolysin was the most frequent virulence factor present in the isolates analyzed. A. hydrophila led to the mortality of the Nile tilapia fingerlings, regardless of the absence or quantity of virulence genes tested.

Management practices to control gastrointestinal parasites in sheep farms in Minas Gerais, southeastern Brazil

Parasite related problems are considered one of the major health problems for sheep breeding, causing considerable economic losses to commercial husbandry. The aim of this study was to determine the technological level and the level of knowledge of farmers regarding management practices to control gastrointestinal parasites in sheep in Minas Gerais state, southeastern Brazil. The analysis was based on 213 questionnaires applied by official veterinarians of the State Government Agency for Animal Health (Instituto Mineiro de Agropecuária, IMA), covering 16.6% of all counties. From two hundred and thirteen sheep farms sampled, 117 farms had their technological level determined. From the samples, 0.9% were characterized as high level, 45.3% as medium, and 53.0% as low technological level. The flock size ranged from 2 to 1843 with an average of 80.5 sheep per farm. The majority of the sheep production systems was extensive/semi-extensive (74.5%). The management practices adopted by the farmers to reduce parasitism were: split young and adult animals (5.6%), change pasture after deworm the animals (5.2%), use quarantine for incoming animals (2.3%), deworm newly arrived sheep (1.5%), and have regular technical assistance (31.9%). Although 76.5% of the farmers medicate the animals, treatments were performed without any major technical criteria, with an average interval of 4.6 months. The most commonly used drug families were macrocyclic lactones (38.5%) and benzimidazoles (24.9%). The management practices adopted in Minas Gerais are based on old recommendations and may not return in a good set of strategies to prevent parasite infections. Field observations reinforce the finding where farmers have obtained unsatisfactory results in maintaining the health and productivity level of their enterprises.

Effects of the 2,4-D herbicide on gills epithelia and liver of the fish Poecilia vivipara

The 2,4-dichlorophenoxyacetic acid, usually named 2,4-D is one of the most widely used herbicides in the world. Acute toxicity of 2,4-D herbicide was investigated through its effects on guppies (Poecilia vivipara Bloch et Schneider 1801). Fish were exposed to the herbicide at concentrations of 10, 20 and 40µl per liter of water for 24 hours to determine its effects on gills and liver epithelia. The estimated LC50 was 34.64µl of 2,4-D per liter of water. Histochemical analyses and Feulgen's reaction were conducted to detect glycoconjugates and DNA, respectively, in gills and liver epithelia. Histochemistry revealed qualitative variations of glycoconjugates present on mucous cells and granules. The four types of mucous cells contained neutral granules, acids, or both. Increasing amounts of syalomucins were observed from the control group to the group exposed to the highest concentration of 2,4-D, suggesting increased mucous viscosity and the formation of plaques that could inhibit gas exchange and osmoregulation. Lamellar fusion observed in the group exposed to 40µl of 2,4-D suggests a defense mechanism. Hepatocytes showed vacuolization in the 10 and 20µl/L groups. The 40 µl/L group showed normal hepatocytes as well as changed ones, many Ito cells, micronuclei, and nuclear swelling. These effects may be associated with toxicity or adaptative processes to cellular stress. The data from this study indicates the importance of assessing similar risks to aquatic species and suggests that Poecilia vivipara is an adequate biological model for analysis of environmental contamination.

Analysis of hematologic and serum chemistry values of Spheniscus magellanicus with molecular detection of avian malarial parasites (Plasmodium spp.)

Magellanic penguins (Spheniscus magellanicus) routinely migrate from their breeding colonies to Southern Brazil often contracting diseases during this migration, notably avian malaria, which has been already reported in Brazil and throughout the world. Detection of Plasmodium spp. in blood smears is the routine diagnostic method of avian malaria, however it has a low sensitivity rate when compared to molecular methods. Considering the negative impact of avian malaria on penguins, the aim of this study was to detect the presence of Plasmodium spp. in Magellanic penguins using Polymerase Chain Reaction (PCR) and by verifying clinical, hematological, and biochemical alterations in blood samples as well as to verify the likely prognosis in response to infection. Blood samples were obtained from 75 penguins to determine packed cell volume (PCV), red blood cell (RBC) and white blood cell (WBC) counts, mean corpuscular volume (MCV), uric acid, total protein, albumin, globulin and aspartate aminotransferase (AST) activity levels. Whole blood samples were used for PCR assays. Plasmodium spp. was detected in 32.0% of the specimens using PCR and in 29.3% using microscopic analyses. Anorexia, diarrhea and neurological disorders were more frequent in penguins with malaria and a significant weight difference between infected and non-infected penguins was detected. PCV and MCV rates showed no significant difference. RBC and WBC counts were lower in animals with avian malaria and leukopenia was present in some penguins. Basophil and lymphocyte counts were lower in infected penguins along with high monocyte counts. There was no significant difference in AST activities between infected and non-infected animals. There was a significant increase in uric acid values, however a decrease in albumin values was observed in infected penguins. Based on this study, we concluded that Plasmodium spp. occurs in Magellanic penguins of rehabilitation centers in Southeastern Brazil, compromising the weight of infected animals with clinical alterations appearing in severe cases of this disease. It was also noted that, although the hematological abnormalities presented by these animals may not have been conclusive, leukopenia, monocytosis and the decrease of basophils and lymphocytes revealed an unfavorable prognosis, and Plasmodium spp. infections may progress with elevated uric acid concentration and low albumin levels.

Gastrointestinal parasites of swine raised in different management systems in the State of Rio de Janeiro, Brazil

Abstract: From 2012 to 2013 were surveyed gastrointestinal parasites from pig farms located in different municpaliyies in the state of Rio de Janeiro. Fecal samples from 790 pigs were collected from the rectum on 88 family farms and 702 farms with industrial production. The samples were subjected to Faust et al., Sheather, Ritchie, Lutz and direct examination faecal techniques. The estimated parasite prevalence was 93.1% in family farms and 59.1% in industrial farms. Balantidium coli, coccidia and Entamoeba sp. were the parasites with the highest frequencies, and the male and female reproductive categories and fatteners pigs the most infected (p<0.05). Trophozoites of B. coli were most evident in stool samples from semi-solid followed by solid and diarrheal consistencies. Strongyles eggs and Trichuris suis have been detected exclusively in family farms. Ascaris suum eggs and Strongyloides ransomi showed low frequency. The high degree of parasitism, especially protozoa, indicates the need to reassess the management of pigs in both types of production.

First description of microchromosome in the Anostomidae fish Schizodon nasutus from Argentina

Thirty-six specimens of Schizodon nasutus (Anostomidae-Characiformes) from the middle Paraná River (Posadas, Argentina) were analyzed cytogenetically. The karyotype of this species was similar to those described for this species in the literature. C-banding technique showed a rich heterochromatic pattern relative to other Anostomidae species. The NORs were located on one chromosome pair in terminal position and showed a very marked size heteromorphism. A microchromosome was observed with a frequency of about 20% in the sample studied. This additional element was punctiform, negative C-band, and constant in all metaphase plates of the seven carriers. The present study is the first karyotypic approach to Schizodon nasutus from Argentina and the first description of microchromosome in Anostomidae