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Fernando de Noronha (Distrito Estadual), Brazil

The article aims at studying reproduction aspects of Poecilia vivipara; Jenynsia multidentat; Phalloptychus januarius; ichthyoplankton composition and spatial distribution; feeding aspects of Jenynsia multidentata and Geophagus brasiliensis; considered benthopelagic species. Reproductive aspects of Poecilia vivipara population embryos showed four developmental stages until birth with sexual differentiation occurring after 15mm. Jenynsia multidentata reproduces throughout the whole year, with its first maturation occurring at 32mm. Embryos showed four developmental stages until birth, with sexual differentiation occurring after 13mm. Some aspects of Phalloptychus januarius reproduction, such as male and female proportion, female first pregnancy size, different stages of embryologic development and reproductive activity, were studied. First maturation was observed since 19mm total length. The embryos showed four different embryonic stages until the age of birth. The male's sexual dimorphism could be observed from 15mm total length. Jenynsia multidentata, with its first maturation occurring at 32mm. Embryos showed four developmental stages until birth, with sexual differentiation occurring after 13 \mm; ichthyoplankton were represented by families Atherinopsidae, Blenniidae, Clupeidae, Engraulidae, Gerreidae, Gobiidae, Mugilidae, Sciaenidae and Achiridae. Benthic fish diet, the principal feed components were represented by 60, 14% of organic matter, 26.04% of Navicula, 3,38% of Cladophora, 1.72% of Polychaeta, 1.16% of eggs, 1.04% of Pleurosigma, 0,83% of Chroococcus, 0.77% of Enteromorpha, 0,74% of Amphora, besides Ectocarpus, insect and microcrustacean fragments, Terpsinoe, Psychodidae, fry, Coscinodiscus, Cocconeis, barnacles, nauplius, Gomphonema, Isopoda, Amphipoda, Chilopoda and Ephidridae, reaching a total of 3,47%; The main stomachal items found in benthonic fishes were: particulate organic matter, eggs, polychaetae, algae and quartz crystals. The highest percentage of organic matter was founded in the Microbius meeki, Prinotus punctatus, Dormitator maculatus and Genidens genidens stomachs. In the Dormitator maculatus, Gobionellus oceanicus and Achirus lineatus stomachs were observed the highest percentages of polychaetae, while in A. lineatus and in A. tajasica stomachs were found a high percentage of quartz crystals probably eaten with epibenthic material. Source

Vilela R.C.,Federal University of Rio de Janeiro | Benchimol M.,University of Saint Ursula
Memorias do Instituto Oswaldo Cruz | Year: 2012

Trichomonas vaginalis and Tritrichomonas foetus are parasitic, flagellated protists that inhabit the urogenital tract of humans and bovines, respectively. T. vaginalis causes the most prevalent non-viral sexually transmitted disease worldwide and has been associated with an increased risk for human immunodeficiency virus-1 infection in humans. Infections by T. foetus cause significant losses to the beef industry worldwide due to infertility and spontaneous abortion in cows. Several studies have shown a close association between trichomonads and the epithelium of the urogenital tract. However, little is known concerning the interaction of trichomonads with cells from deeper tissues, such as fibroblasts and muscle cells. Published parasite-host cell interaction studies have reported contradictory results regarding the ability of T. foetus and T. vaginalis to interact with and damage cells of different tissues. In this study, parasite-host cell interactions were examined by culturing primary human fibroblasts obtained from abdominal biopsies performed during plastic surgeries with trichomonads. In addition, mouse 3T3 fibroblasts, primary chick embryo myogenic cells and L6 muscle cells were also used as models of target cells. The parasite-host cell cultures were processed for scanning and transmission electron microscopy and were tested for cell viability and cell death. JC-1 staining, which measures mitochondrial membrane potential, was used to determine whether the parasites induced target cell damage. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling staining was used as an indicator of chromatin damage. The colorimetric crystal violet assay was performed to analyse the cytotoxicity induced by the parasite. The results showed that T. foetus and T. vaginalis adhered to and were cytotoxic to both fibroblasts and muscle cells, indicating that trichomonas infection of the connective and muscle tissues is likely to occur; such infections could cause serious risks to the infected host. Source

Vilela R.C.,Federal University of Rio de Janeiro | Benchimol M.,University of Saint Ursula
Memorias do Instituto Oswaldo Cruz | Year: 2011

Trichomonas vaginalis and Tritrichomonas foetus are human and bovine parasites, respectively, that provoke the sexually transmitted disease trichomoniasis. These extracellular parasites adhere to the host epithelial cell surface. Although mucinases and proteases have been described as important proteins for parasite adhesion to epithelial cells, no studies have examined the role of the keratin molecules that cornify the vaginal epithelium. Here, we investigated the interaction of T. vaginalis and T. foetus with human keratin in vitro; additionally, adherence assays were performed in cattle with T. foetus to elucidate whether trichomonads were able to interact with keratin in vivo. We demonstrated that both T. vaginalis and T. foetus interacted directly with keratin. Additionally, the trichomonads ingested and digested keratin, shedding new light on the Trichomonas infection process. Source

Chaves Vilela R.,Federal University of Rio de Janeiro | Chaves Vilela R.,National Institute of Metrology of Brazil | Benchimol M.,University of Saint Ursula
Memorias do Instituto Oswaldo Cruz | Year: 2013

Trichomonas vaginalis and Tritrichomonas foetus are parasitic protists of the human and bovine urogenital tracts, respectively. Several studies have described the cytotoxic effects of trichomonads on urogenital tract epithelial cells. However, little is known about the host cell response against trichomonads. The aim of this study was to determine whether T. foetus and T. vaginalis stimulated the release of the cytokine interleukin (IL)-10 from cultured bovine epithelial cells. To characterise the inflammatory response induced by these parasites, primary cultures of bovine oviduct epithelial cells were exposed to either T. vaginalis or T. foetus. Within 12 h after parasite challenge, supernatants were collected and cytokine production was analysed. Large amounts of IL-10 were detected in the supernatants of cultures that had been stimulated with T. foetus. Interestingly, T. vaginalis induced only a small increase in the release of IL-10 upon exposure to the same bovine cells. Thus, the inflammatory response of the host cell is species-specific. Only T. foetus and not T. vaginalis induced the release of IL-10 by bovine oviduct epithelial cells. Source

Midlej V.,University of Saint Ursula | Midlej V.,Federal University of Rio de Janeiro | Benchimol M.,University of Saint Ursula
Parasitology | Year: 2010

This study reports that the cytopathic effect of Trichomonas vaginalis, an important human parasite of the urogenital tract, occurs due to mechanical stress and subsequent phagocytosis of the necrotic cells. The investigation was done using a primary culture of bovine oviduct epithelial cells (BOECs), grown either in monolayers or as floating cells. Trophozoites displaying different virulence levels were co-incubated with BOECs for times varying between 1 min and 48 h. Analyses were performed using videomicroscopy, scanning and transmission electron microscopy, colourimetric assays and cytochemistry. Injury was observed as early as 1 h after incubation, while after 12 h the host cells were severely damaged when a fresh trichomonad isolate was used. Trichomonads attack the host cells by clustering around them. Mechanical stress on the microvilli of the host cells was observed and appeared to induce plasma membrane damage and cell death. After membrane injury and lysis, fragments of the necrotic cells were ingested by trichomonads. Phagocytosis occurred by trichomonads avidly eating large portions of epithelial cells containing the nucleus and other organelles, but living or intact cells were not ingested. Necrotic fragments were rapidly digested in lysosomes, as shown by acid phosphatase and ruthenium red assays where only the BOECs were labelled. The lytic capacity of the trichomonads was more pronounced in host cell suspensions. © 2009 Cambridge University Press. Source

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