Detection of the genotoxicity of air pollutants in and around the city of São Paulo (Brazil) with the Tradescantia-micronucleus (Trad-MCN) assay

Tradescantia pallida cv. purpurea, a popular garden plant in Brazil, was used for the Tradescantia micronucleus (Trad-MCN) assay. In situ monitoring of the genotoxicity of air pollutants was carried out by sentinel approach, using the plant grown in the field or using the plants in pots which were carried to the monitoring sites. Two highly polluted sites, in S?o Paulo city (Cerqueira Cesar and Congonhas) and two rural sites (the cities of Pirassununga, 200 km and Caucaia do Alto, 50 km from S?o Paulo, respectively) were chosen for this study, in order to determine the gradient difference of the air pollution levels. Sentinel plants in Congonhas site presented the highest frequency of micronuclei (4.4%), in comparison with 2.2 and 2.3% found in plants from Pirassununga and Cerqueira Cesar sites, respectively (Kruskal-Wallis; P<0.020). Significant increases (F test; P<0.0001) in the frequency of micronuclei were observed in plants exposed in the polluted urban sites (Cerqueira Cesar: 5.7%; Congonhas: 7.1% and Caucaia do Alto: 2.3%). The increase in the frequency of micronuclei observed indicates the potential risk of mutagenicity in presence of high concentrations of pollutants.     

Investigation of biota associated and natural infection by sporulated bacteria in Culicidae larvae from São Paulo state, Brazil

The aim of this study was to investigate the naturally occurring bacteria from Culicidae larvae found in São Paulo state between 2006 and 2008 from the Tiete Ecological Park in the municipality of Caraguatatuba. Bacterial strains were obtained after surface sterilization of larvae followed by thermal treatment and incubation in bacteriological media under laboratory conditions. Identification was determined using cytomorphology, biochemical and physiological tests. Strains were characterized by qualitative evaluation of biological activity against Culicidae larvae, comparing protein profiles obtained by electrophoresis of crystal protoxins, electrophoresis of Lysinibacillus sphaericus isoenzymes, detection of the L₂ fraction of Hemolytic BL enterotoxin and amplification of DNA using Multiplex-PCR to detect HBL, NHE, CytK, BceT and EntFM enterotoxins. The results obtained in this study demonstrated that the endosymbiotic bacterial diversity belonging to Bacillus and related genera associated with Culicidae larvae is limited to a number of species that does not vary throughout the seasons.     

Prevalence of Clostridium spp. and Clostridium difficile in children with acute diarrhea in São Paulo city,Brazil

Species of Clostridium are widely distributed in the environment, inhabiting both human and animal gastrointestinal tracts. Clostridium difficile is an important pathogen associated with outbreaks of pseudomembranous colitis and other intestinal disorders, such as diarrhea. In this study, the prevalence of Clostridium spp. and C. difficile, from hospitalized children with acute diarrhea, was examined. These children were admitted to 3 different hospitals for over 12 months. Eighteen (20%) and 19 (21%) stool specimens from children with (90) and without (91) diarrhea respectively, were positive to clostridia. Only 10 C. difficile strains were detected in 5.5% of the stool samples of children with diarrhea. None healthy children (without diarrhea) harbored C. difficile. From these 10 C. difficile, 9 were considered as toxigenic and genotyped as tcdA+/tcdB+ or tcdA-/tcdB+, and 1 strain as nontoxigenic (tcdA-/tdcB-). They were detected by the citotoxicity on VERO cells and by the multiplex-polymerase chain reaction. Thirty clinical fecal extracts produced minor alterations on VERO cells. The presence of C. difficile as a probable agent of acute diarrhea is suggested in several countries, but in this study, the presence of these organisms was not significant. More studies will be necessary to evaluate the role of clostridia or C. difficile in diarrhoeal processes in children.     

Virulence markers and antimicrobial susceptibility of bacteria of the Bacteroides fragilis group isolated from stool of children with diarrhea in São Paulo, Brazil

Bacteroides fragilis has been isolated from several human and non-human monomicrobial and mixed infections. In this study, some virulence markers and the antimicrobial susceptibility of bacteria of the B. fragilis group isolated from children's stools were evaluated. All the 64 isolates showed the following characteristics: capsulated, beta-hemolytic, hydrophilic, and serum-resistant. Only, 24 (37.5%) strains were resistant at 60 masculine C, for 30 min, and among them, 12 (18.75%) were resistant at 60 masculine C, for 60 min. Also, none strain was resistant at 100 masculine C. Four strains were able to hemagglutinate erythrocytes and D-mannose, D-galactose, D-arabinose, and D-xylose inhibited hemagglutination in 2 B. fragilis strains (p76a, p76b). The hemagglutination in the strain B. uniformis p3-2 was inhibited by D-xylose and D-galactose. The bft gene detection and the enterotoxin production were observed only in 13 EF-enterotoxigenic species. Fragilysin activity was confirmed on HT-29 cells. The antimicrobial determination confirmed that both imipenem and metronidazole were efficient against B. fragilis species; all the strains were resistant to lead and nickel. Plasmids of 2.9, 4.4, 4.8, and 8.9 kb were observed in 6 tested strains. These results show the values of the species identification from clinical infections, as well as of the periodic evaluation of the resistance patterns of the B. fragilis group at Brazilian medical institutions.     

Ecological distribution of Penaeus schmitti (Dendrobranchiata: Penaeidae) juveniles and adults on the southern coast of São Paulo state,Brazil

This study aimed to describe the ecological distribution and the effects of environmental factor oscillation on the life cycle of Penaeus schmitti along the coastal area of Cananéia, southern São Paulo state, Brazil. Shrimp and environmental factors were sampled monthly from July 2012 to May 2014 at seven sampling stations covering both estuarine and marine environments, using a shrimp fishing boat. A total of 273 juveniles and 829 adults were sampled, and there were significant differences in body size (carapace length – CL) throughout the seasons (ANOVA). Smaller animals were observed in the summers of 2013 and 2014 and at sites closer to the coast, which are under estuarine influence. Adults were observed mostly in autumn and in deeper regions. We detected a positive relationship between the abundance of juveniles and the bottom water temperature and between the abundance of adults and the water salinity (canonical correspondence analysis). The presence of smaller individuals in the estuarine environment demonstrates the importance of the estuaries in this species’ ontogeny, mainly concerning their protection, since this environment has physical (depth) and physiological (salinity) barriers to their predators. Furthermore, we could clearly observe the plasticity of juveniles in relation to environmental factors. In contrast, adults were less tolerant to the variation in environmental factors, mainly water salinity, which was a limiting factor of their distribution. Seasonal differences in body size could be directly associated to this species’ life cycle and characterized by trophic and reproductive migratory activities between the estuarine and oceanic regions.     

Prevalence and mean intensity of infestation by Carcinonemertes carcinophila imminuta (Nemertea: Carcinonemertidae) in the gills of Callinectes danae and Callinectes ornatus (Decapoda: Portunidae) from São Sebastião,Brazil

The nemerteans of the genus Carcinonemertes live in association with decapod crustaceans. Juveniles of Carcinonemertes carcinophila imminuta Humes, 1942 are found in the gills of their hosts. A total of 281 specimens (52 males and 229 females) of Callinectes danae Smith, 1869 and 373 (332 males and 41 females) of Callinectes ornatus Ordway, 1863 were inspected for the occurrence of Carcinonemertes carcinophila imminuta in their gills. The prevalence and mean intensity of infestation by these nemerteans with regard to sex, maturity, condition of adult female crabs (ovigerous or non ovigerous), size (carapace width) and molt stage of hosts were evaluated. A prevalence of infestation by Carcinonemertes carcinophila imminutaof 39.1% was found in the population of Callinectes danae; the mean intensity of infestation was 12.0±2.7, while intensity ranged from 1 to 268. In this host species, significant differences in prevalence were observed between males and females, juveniles and adults and ovigerous and non-ovigerous adult females. Prevalence of infestation did not differ significantly among crabs in different molt stages. Mean intensity did not differ significantly between males and females nor among crabs in different molt stages. Significant differences in mean intensity were observed between ovigerous and non-ovigerous adult females of Callinectes danae. A positive correlation was observed between prevalence of infestation and the carapace width of Callinectes danae females. The prevalence of infestation in Callinectes ornatus was 8.0%; the mean intensity of infestation was 2.7±0.4 while intensity ranged from 1 to 9. Prevalence and mean intensity of infestation did not differ significantly between males and females and juveniles and adults. Prevalence did not differ significantly among crabs in different molt stages. No correlation was observed between the prevalence of infestation and the carapace width of males and females of Callinectes ornatus.     

Molecular detection and isolation of human T-cell lymphotropic virus type I (HTLV-I) from patients with HAM/TSP in São Paulo,Brazil

Background: Infection with HTLV-I is etiologically linked with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). However some patients with chronic progressive paraparesis resembling HAM/TSP have been shown to be infected with HTLV-II.Objective: To clarify the role of each of these human retroviruses in the etiology of HAM/TSP in São Paulo, Brazil.Study design: A detailed serological and molecular analysis of HTLV-I/II infection was performed in a cohort of 19 patients with HAM/TSP attending a neurological clinic.Results: Plasma samples analyzed for anti-HTLV-I/II antibodies using a Western blot assay, comprising HTLV-I (rgp46^I)- and HTLV-II (rgp46^II)-specific recombinant env epitopes, demonstrated reactivity to rgp46^I and hence were typed as seropositive for HTLV-I. Presence of HTLV genomic sequences in peripheral blood mononuclear cells (PBMC) was sought after by PCR using consensus primers SK 110 and SK 111 for the pol region of HTLV proviral DNA followed by hybridization with type-specific probes—SK 112 (HTLV-I) and SK 188 (HTLV-II). Southern blots from all individuals hybridized with SK 112 but not with SK 188, further confirming HTLV-I infection. Cocultivation of PBMC from eight of these patients with activated lymphocytes from normal individuals resulted in active viral production, detected as presence of soluble p24^gag antigen in culture supernatants. Investigation of risk factors for HTLV-I infection in these individuals revealed that five out of 19 patients studied (26.3%) had received blood transfusions previous to disease onset.Conclusions: We demonstrate HTLV-I as the only viral type involved in the etiology of HAM/TSP in a cohort from São Paulo, Brazil, and emphasize that prevention measures, including widespread routine screening of blood donations for HTLV should be conducted in Brazil.     

Bat flies (Diptera: Streblidae, Nycteribiidae) parasitic on bats (Mammalia: Chiroptera) at Parque Estadual da Cantareira, São Paulo, Brazil: parasitism rates and host-parasite associations

A total of 443 bat flies belonging to the families Nycteribiidae and Strelidae, were collected on 22 species of bats (Molossidae, Phyllostomidae, and Vespertilionidae) from Parque Estadual da Cantareira (S?o Paulo, Brazil), between January, 2000 and January, 2001. Eighteen new occurrences of bat flies were recorded on Anoura geoffroyi (Anastrebla caudiferae), Glossophaga soricina (A. caudiferae), Sturnira lilium (Trichobius phyllostomae, T. furmani, and Paraeuctenodes similis), Artibeus lituratus (A. caudiferae), A. fimbriatus (Megistopoda proxima), A. obscurus (Metelasmus pseudopterus), Myotis nigricans (M. proxima, M. aranea, Paratrichobius longicrus), M. ruber (Anatrichobius passosi, Joblingia sp.), M. levis (A. passosi), M. albescens (A. passosi, Basilia andersoni), and Histiotus velatus (M. aranea). Seven new occurrences were recorded for the state of S?o Paulo, increasing the range for T. tiptoni, T. furmani, M. proxima, Aspidoptera falcata, A. caudiferae, A. modestini and B. andersoni. The relationships between parasitism and host sex, reproductive stage, age hyperparasitism by fungi are discussed.     

Impact of the Três Marias dam on the reproduction of the forage fish Astyanax bimaculatus and A. fasciatus from the São Francisco River,downstream from the dam,southeastern Brazil

Alterations to the hydrologic regime downstream from hydroelectric dams include thermal disturbances which may have an impact on the reproductive success of fish. In order to make a comparative analysis of forage fish reproduction in two sections of the São Francisco River downstream from the Três Marias hydroelectric power plant, we captured 606 specimens of Astyanax fasciatus (n?=?465) and A. bimaculatus (n?=?141) at 2-month intervals between November 2009 and October 2010. Fish were captured in two sections of the São Francisco River: section 1, encompassing the first 34 km immediately downstream from the dam; section 2, after the confluence with the Abaeté River, 34–54 km downstream from the dam. The canonical correlation test indicated that for both species, female reproduction is more dependent on environmental factors than male reproduction. Compared to section 1, the specimens captured in section 2 were more abundant and the females of both species presented larger total length, body weight, gonadosomatic index and fecundity values. Higher values of water temperature, dissolved oxygen and turbidity during the rainy season (September to February) were also recorded for section 2, when compared to section 1 where the physical–chemical conditions of the water do not favour reproduction. Based on this analysis of reproductive parameters, this study shows, for the first time, that the reproductive activity of two species of forage fishes, A. fasciatus and A. bimaculatus, from the section of the São Francisco River immediately downstream from the Três Marias dam is disrupted and that the Abaeté River is an important tributary for the reproductive success of these species.     

Late Quaternary grassland (Campos), gallery forest,fire and climate dynamics,studied by pollen,charcoal and multivariate analysis of the São Francisco de Assis core in western Rio Grande do Sul (southern Brazil)

We present a detailed pollen and charcoal record of a 368-cm-long sediment core from the lowland Campos (grassland) region near the city of São Francisco de Assis in the western Rio Grande do Sul State in southern Brazil. Based on four AMS radiocarbon dates, the record represents the last about 22,000 cal yr BP. The region was naturally covered by Campos throughout the recorded glacial and Holocene period under cold and relatively dry and warm and dry condition, respectively. Initial expansion of gallery forest after 5170 cal yr BP indicates a change to wetter climatic conditions. Maximum extent of gallery forest after 1550 cal yr BP reflects the wettest recorded period. There is some evidence of plant migration from the eastern Atlantic coastal lowland reaching the western lowland, first after mid Holocene times by Cecropia and, possibly, species of Myrsine and Moraceae and later, after about 1000 cal yr BP, by species of Alchornea and Acalypha. Multivariate analysis revealed that the long-term pollen composition dynamics is a two-phase process, with random, chaotic changes characterizing some periods when climate conditions were likely more stable, and directional compositional changes (phase transitions) in periods coincide with major climate and/or anthropogenic changes. Natural fires were rare during full- and lateglacial periods, but became frequent at the beginning of the Holocene, suggesting the beginning of human occupation of the western lowland at that time. Highest fire frequency is found during the wet late Holocene period, suggesting an increase of indigenous populations in the São Francisco de Assis region.