Area Of Northeastern Brazil Research Articles

Helminths of freshwater turtles in Northeastern Brazil: parasite–host–environment relationships

ABSTRACT The parasitic fauna of reptiles is considered understudied compared to that of other vertebrates and is even less well known than the parasitic fauna of chelonians. Yet parasites are considered one of the main controllers of host populations because they can strongly impact population structure and species diversity. The objective of the present study was to identify the helminth fauna infecting freshwater turtles Phrynops geoffroanus and Mesoclemmys tuberculata, to evaluate the effects of host features (body mass and sex) and seasonality (dry and rainy seasons) on the abundance of parasites, and to compare infection rates in each host species between different biomes (Caatinga and Atlantic Forest) in an area of Northeastern Brazil. We found seven species of helminths that belong to Nematoda (Physaloptera sp., Serpinema amazonicus, Serpinema monospiculatus and Spiroxys figueiredoi), Cestoda (unidentified specimen), Digenea (Echinostomatidae) and Monogenea (Polystomoides brasiliensis). For both freshwater turtle species, we did not find a significant difference in the abundance of helminths related to the maximum carapace length, body mass or host sex; however, males had higher prevalence than females, while females presented greater abundance when infected. We observed significant differences in the infection levels between biomes and between seasons (dry and rainy), where the Atlantic Forest specimens showed higher infection rates compared to the Caatinga and the highest rates occurred in the dry season. The main parasitological parameters observed in P. geoffroanus and M. tuberculata showed that the studied biomes directly influenced the levels of parasitic infection. Variations in habitat characteristics can directly influence patterns of helminth diversity and abundance, and interactions between these characteristics can generate differences in parasitism rates of the same host species in different environments.

Impact of the COVID-19 pandemic on the actions of the Schistosomiasis Control Program in an endemic area in Northeastern Brazil

Schistosomiasis remains a serious public health concern in Brazil and the Schistosomiasis Control Program (PCE) was elaborated to assist in the control of the disease. Nevertheless, the irruption of the COVID-19 pandemic may have impacted the program. Herein, we assessed the impact of the pandemic on PCE actions in an endemic area in the region with the highest positivity rate for schistosomiasis in Brazil. We conducted an ecological, population-based study using data from the PCE of the state of Alagoas, between 2015 and 2021, to calculate the percentage of change. The temporal trend analysis was performed using the segmented log-linear regression model. To evaluate the spatial distribution of the data, choropleth maps were made showing the values of the% of change. Moran maps was elaborated to indicate the critical areas. Our analysis showed a decrease in the population surveyed in 2020 (-41.00%) and 2021 (-18.42%). Likewise, there was a reduction in the number of Kato-Katz tests performed (2020 = -43.45%; and in 2021 = -19.63%) and, consequently, a drop in the rate of positive tests (-37.98% in 2020 and -26.14% in 2021). Importantly, treatment of positive cases was lower than 80% (77.44% in 2020 and 77.38% in 2021). Additionally, spatial clusters with negative percentage values of up to -100% of the PCE indicators were identified mostly in the municipalities of the coastal areas that are historically most affected by schistosomiasis. Taken together, our analyzes corroborate that PCE actions in endemic municipalities of Alagoas were impacted by the COVID-19 pandemic.

Parasitism on bats by bat flies in remnants of a humid forest enclave area in Northeastern Brazil.

Flies are the main bloodsucking ectoparasites of Neotropical bats. The aim of this study was to describe the community of flies on bats from a humid forest enclave, surrounded by the semiarid landscape of the Caatinga domain, in Northeastern Brazil. In addition, we tested the influence of dry and rainy periods on the parasitological indices. Fieldwork was carried out in three anthropized remnants of a humid forest enclave in the Agreste mesoregion of Pernambuco state, Northeastern Brazil. Bats were captured monthly, from August 2018 to July 2019, and the ectoparasites were collected. Overall, 807 bats of 14 species and 11 genera of the families Phyllostomidae (13 spp.) and Vespertilionidae (1 sp.) were captured. Only four bat species had >50 individuals captured, and Carollia perspicillata was the most abundant species (259/807; 32%). Five hundred and seventy-one bat flies from 13 species (11 Streblidae and 2 Nycteribiidae) were collected, of which Trichobius joblingi was the most prevalent fly (197/571; 34.5%). Only the parasitism by T. joblingi was influenced by seasonality, with higher prevalence (P=0.01) and intensity of infestation (P=0.02) in the dry season. No lesions associated with parasitism were observed in any of the captured bats. Our results suggest that the bat-fly relationship can be affected in different ways by environmental variables, depending on the species involved. The results of this work contribute to the knowledge about ectoparasites of bats in the Neotropical region, with emphasis on humid forest enclaves, where studies of the host-parasite-environment relationship are scarce.

Croton L. (Crotonoideae, Euphorbiaceae) em uma área protegida do Nordeste do Brasil

Abstract Croton is the largest genus of Crotonoideae Burmeist. (ca. 1200 species), with approximately 300 species distributed in all the phytogeographic domains in Brazil. The Chapada of Araripe Environmental Protection Area (CA-EPA) is one of the largest protected areas in northeastern Brazil and comprises many different types of vegetation. Considering the expressive representation of Croton in that northeastern region and its morphological complexity, we carried out a taxonomic study of the species occurring in the CA-EPA. The analysis of collections deposited in regional herbaria, together with field observations, revealed 18 Croton species, five of which had never been cited as occurring in the study area; seven of those taxa are endemic to the Brazilian semiarid region. Croton species were recorded in all of the vegetation types in the CA-EPA, especially in the “carrasco” and “caatinga” vegetation. The plants habits, the shapes of their stipules, extrafloral nectaries, indumenta, and staminate and pistillate sepals were important characteristics for their differentiation.

Habitat use of Guiana dolphin Sotalia guianensis in a heavily urbanized embayment

Understanding environmental and anthropogenic variables that influence the presence of dolphins in coastal areas is fundamental for conservation planning and forecasting. In this study, we applied generalized additive models to identify areas of high probability of occurrence of Guiana dolphins in Mucuripe embayment, a heavily urbanized area in northeastern Brazil. Sighting and effort data were collected during systematic, boat-based surveys between 2009 and 2011. Models were built using 70% of the data to test the model and 30% to evaluate its predictive performance. Variables investigated included depth, slope, seabed complexity, and distance to the coast, breakwaters, and the fishing grounds. The best model explained 40.8% of the total deviance. Seabed complexity, distance to the breakwaters and distance to the fishing grounds were the most important variables, with dolphins showing a preference for areas with a less complex seabed immediately adjacent to the breakwaters (<500 m, decreasing with distance) as well as a preference for fishing grounds (again decreasing with distance). Using the validation data, the model showed excellent performance. The habitat use and preference of Guiana dolphins in the study area seem to be mainly influenced by foraging opportunities, with dolphins concentrating in areas with higher prey abundance and where foraging success is higher because of a strategy called ‘barrier-feeding’, in which animals herd fish against piers, breakwaters, and the coast.

Bat-parasite interaction networks in urban green areas in northeastern Brazil.

Interaction networks can provide detailed information regarding ecological systems, helping us understand how communities are organized and species are connected. The goals of this study were to identify the pattern of interaction between bats and ectoparasites in urban green areas of Grande Aracaju, Sergipe, and calculate connectance, specialization, nesting, modularity and centrality metrics. Bats were captured using 10 mist nets inside and on the edges of the fragments, and the collected ectoparasites were stored in 70% alcohol. All analyses were performed using R software. The interaction network consisted of 10 species of bats and 13 ectoparasites. Connectivity was considered low (0.12). The specialization indices for ectoparasites ranged from 0.50 to 1.00, and the value obtained for the network was 0.96, which is high. The observed nesting metric was low (wNODF = 1.47), whereas the modularity was high (wQ = 0.74), indicating that the studied network had a modular topology. All centrality metrics had low values. The observed modularity may have been caused by the evolutionary history of the bats and ectoparasites involved and the high specificity index of the interactions. The low centrality values may be associated with low connectivity and a high degree of specialization. This study provides relevant information on bat–parasite interactions in an urban environment, highlighting the need for further studies to improve our understanding of host–parasite interaction networks.

Egg production by the exotic shrimp Athanas dimorphus (Caridea: Alpheidae) in a harbor area in northeastern Brazil

The shrimp Athanas dimorphus was recently recorded in the Western Atlantic, with successive records of introduction along the Brazilian coast. The present study aimed to investigate aspects related to propagule pressure of this shrimp, such as egg production, fecundity, egg volume, and the correlation between fecundity and female size. Additionally, we aimed to determine whether the species is established in the locality, in addition to inferring its ability as a propagule donor to adjacent regions. The following hypotheses were formulated: (1) the species has a reproductively active population in the studied area; (2) the studied population shows continuous reproduction throughout the year. Ovigerous females were collected monthly in the intertidal region of Praia do Paraíso, State of Pernambuco, northeastern Brazil, between April 2017 and March 2018. A total of 524 ovigerous females were sampled. Of these, 362 females carried normal eggs – 324 with eggs in stage I of embryonic development, 5 in stage II, 33 in stage III – 161 had abnormal eggs, and 1 carried eggs in the hatching stage. Only females carrying normal eggs were used in the analyses. The females’ carapace length and egg number and volume were measured and correlated. Mean fecundity in stage I was 63.2 ± 39.1, with egg number decreasing significantly between stages I and III. The mean egg volume increased significantly between stages I and III, presenting a total increase of 35%. The fecundity and size of females were positively correlated. Our results meet the two formulated hypotheses, indicating that A. dimorphus has a reproductively active population in the study area, with continuous reproduction throughout the year. As predicted by the propagule pressure theory, species with such characteristics are considered to be effective invaders, increasing their chances of reaching and establishing in new areas.

Ectoparasitic flies of bats (Mammalia: Chiroptera) in urban green areas of northeastern Brazil.

In urban and degraded areas, ectoparasite abundance can be affected by increasing human population density and habitat fragmentation. This study aimed to characterize the ectoparasitic fly community associated with bats in the urban green areas of Sergipe, Brazil. Campaigns were conducted monthly, for two consecutive nights, between September 2019 and February 2021. To capture the bats, ten mist nets were set up inside and at the edge of the habitat fragments. All ectoparasites found were removed from the bats and stored in 70% alcohol. The specificity index, parasitological rates, and level of parasite aggregation were calculated, and the influence of host sex and seasonality on parasitological rates were verified for the most parasitized bats. The collected ectoparasites corresponded to the families Nycteribiidae (S = 1; n = 26) and Streblidae (S = 13; n = 849), with Trichobius costalimai and Medistopoda aranea being the most abundant species. For some interactions, there was an influence of host sex on the prevalence rates, with the highest number of parasites being found on females, which can be explained by their greater susceptibility to parasitism owing to their long stay in roosts. The seasonality influenced the parasitological rates, and opposing patterns (from what was expected) were observed for some interactions; this influence may be due to the biological differences between parasite species. This study provides relevant data on this interaction, especially for urban areas in northeastern Brazil, expanding the number of studies in the State of Sergipe and promoting future studies.

Nitrogen dynamics in small watersheds in the Atlantic Forest and Cerrado in Northeastern Brazil

The aim of this study was to determine concentrations of nitrogen (N) in two biomes, Atlantic Forest (AF) and Cerrado (CR), at the interface between terrestrial and aquatic ecosystems. This involved evaluating N in vegetation (litterfall), soil and water in small watersheds in environmental protection areas in northeastern Brazil. Soil chemical and physical analyzes were performed and mineralization and nitrification rates were determined. The forms of organic, inorganic and particulate nitrogen in water were determined by spectrophotometry. Two collections were carried out, one in the dry season (October and November 2019) and another in the rainy season (February and March 2020), in two environmental preservation areas, Estação Veracel Private Natural Heritage Reserve - (Atlantic Forest) and Chapada Diamantina National Park (Cerrado), with five small watersheds sampled in each biome. The N concentration in litterfall was similar in both biomes, with averages of 0.69%. In relation to soil and water, N concentrations were higher in AF compared to CR, with concentrations of 0.95 ± 0.40 and 0.59 ± 0.14 µg.Ng-1 of nitrate in the soils of AF and CR, respectively, and 3.53 ± 2.51 µM of nitrate in water in AF and 0.76 ± 0.78 µM in CR.

A simple and cost-effective diagnostic of Macrophomina phaseolina on watermelon by direct PCR

Macrophomina phaseolina (Tassi) Goid is the causal agent of charcoal rot and vine decline in cucurbits such as watermelon. Molecular methods have been used for rapid identification. However, a large number of steps used reduces its applicability. This study aimed to detect M. phaseolina in watermelon from producing areas in Northeastern Brazil by direct PCR. Plant tissue samples were collected from seven producing areas and the DNA was extracted using the CTAB method. Amplifications were performed by direct PCR using the MpKFI/MpKRI primers, then the PCR products were subjected to agarose gel electrophoresis and sequenced. Amplicons of 350 bp were observed in stem tissue samples from three areas. The identity of the samples was confirmed by sequencing. This study represents the first molecular diagnosis of M. phaseolina associated with watermelon in Northeastern Brazil. The methodology presented here can be applied for a reliable and simple diagnosis of the pathogen in other crops.

ESTUDO DO CRESCIMENTO MICELIAL DE MACROPHOMINA SPP. NO BRASIL, SUA PATOGENICIDADE E SENSIBILIDADE A FUNGICIDA

ABSTRACT Macrophomina (Botryosphaeriaceae) is one of the main genera of soilborne phytopathogenic fungi, which causes root and seed rot in more than 800 host plants worldwide. Recent phylogenetic studies identified the species M. phaseolina and M. pseudophaseolina in Trianthema portulacastrum and Boerhavia diffusa in melon and watermelon production areas in northeastern Brazil. Therefore, the objective of this study was: i) to verify the effect of temperature and salinity on the mycelial growth of M. phaseolina, M. pseudophaseolina and M. euphorbiicola, ii) to assess their pathogenicity on melon and watermelon seedlings, and iii) to determine their sensitivity to the fungicide carbendazim. The optimal temperature for mycelial growth rate (MGR) for Macrophomina spp. ranged from 27.18 ºC (CMM4771 – M. pseudophaseolina) to 31.80 ºC (CMM4763 – M. phaseolina). For the effect of salinity on mycelial growth of Macrophomina isolates, the EC50 ranged from 103.76 (CMM4868 – M. euphorbiicola) to 315.25 mM (CMM4801 – M. pseudophaseolina). The pathogenicity test demonstrated that M. phaseolina, M. pseudophaseolina and M. euphorbiicola are pathogenic on melon with M. phaseolina exhibiting a higher level of virulence. Macrophomina euphorbiicola isolates did not cause disease in watermelon. The most sensitive isolates to the fungicide carbendazim were CMM4868, CMM4867 (M. euphorbiicola) and CMM1531 (M. phaseolina) with EC50 of 0.003, 0.012 and 0.012 mg.L-1 a.i., respectively. All Macrophomina spp. used in these experiments were pathogenic to the tested melon and watermelon cultivars with the exception of the M. euphorbiicola isolate that did not cause damage to watermelon.

Ground penetrating radar (GPR) models of the regolith and water reservoir of an underground dam in the Brazilian semiarid region

Underground dams supply water for smallholders in semiarid regions. The aim was to use a ground penetrating radar (GPR) to detect and map the depth to the regolith, validate the size and position and calculate the water reservoir volume of a future underground dam. A GPR survey using a 450 MHz antenna was conducted across an intermittent stream bed in a 0.85-ha area in northeastern Brazil. Nine soil trenches were opened, and the depth to the regolith was recorded at each site. The radargrams were pre-processed, migrated, and the features corresponding to the top of the regolith were delineated in the radargrams. The regolith and the terrain surface were interpolated and plotted in 3D, and the underground water reservoir volume was estimated. The depth to the regolith ranged from 0.81 to 1.60 m at the soil sites, with larger values observed along the intermittent stream thalweg, and close to the dam at the lowest part of the terrain. The radargrams transverse to the slope suggest that the future dam should be 45 m longer and centered at the thalweg position, 22 m south of the initially proposed location. This would increase the water reservoir by 50% to a total of 6 million L. The GPR allowed to properly locate the future underground dam, visualize its shape in 3D and estimate its water reservoir volume, with minimal need of soil sounding.

Helminths of sigmodontine rodents in an agroforestry mosaic in the Brazilian Atlantic Forest: Patterns and processes of the metacommunity structure.

Phylogenetically or taxonomically related hosts may harbour similar parasite communities due to phylogenetic conservatism. In addition, host attributes may favour their exposure to parasites. This study aimed to characterize the helminth fauna of sigmodontine rodents in an Atlantic Forest area in northeastern Brazil and determine the pattern of the helminth metacommunity structure. The influence of host attributes and host taxonomy on the metacommunity structure was also investigated. The most abundant helminth species were Raillietina sp. and Hassalstrongylus lauroi. Euryoryzomys russatus was the most infected host species for helminth parasites, as approximately 81% (35/43) of the animals were infected by at least one helminth species. The helminth metacommunity structure was coherent at both the infracommunity and the component community scales, indicating that species responded to the same environmental gradient. A quasi-Clementsian pattern was observed for the infracommunities, indicating the occurrence of compartments of parasite species that were substituted along the environmental gradient, which was formed by host individuals. A quasi-Gleasonian pattern was found at the component community scale, showing random boundary clumping, which is consistent with the individualistic responses of parasite species to each host species. These patterns corroborated the high values of beta-diversity observed, indicating high species turnover among communities at both scales. Host taxonomic distance was the most important variable explaining the patterns of the helminth metacommunity structure.

Factors affecting searcher efficiency and scavenger removal of bat carcasses in Neotropical wind facilities

AbstractBat fatalities at wind facilities have been reported worldwide, and environmental impact assessments depend on searches for carcasses around wind turbines to quantify impacts. Some of the carcasses may go undetected by search teams or be removed by scavengers during search intervals, so these biases must be evaluated and taken into account in fatality estimation. We investigated the influence of different factors on searcher efficiency and scavenger removal in a dry forest area in northeastern Brazil, one of the regions with the highest density of wind turbines in the Neotropics. We conducted searcher efficiency and scavenger removal trials around 34 wind turbines from January 2017 to January 2018. Searcher efficiency was influenced by cover type, season, and carcass size, ranging between 12% for small bats in shrub vegetation during the rainy season and 96% for large bats in absent or sparse vegetation during the dry season. Carcass type and season affected scavenger removal; carcass persistence time was shorter for chicks (1.2 days) than for bats and mice (2.1 days), and the probability of a carcass persisting for a whole day was higher in the rainy season, while the probability of carcass persistence for 7, 14, and 28 days was higher in the dry season. The scavenger community was composed of canids, birds of prey, and insects, with systematic removal of carcasses by the crab‐eating fox (Cerdocyon thous) throughout the year and by dung beetles in the rainy season. Based on our findings, impact assessments of wind facilities on bats should conduct searcher efficiency trials in all seasons and cover types around wind turbines, using bat carcasses or models of different sizes. Scavenger removal trials should cover all seasons as well, and use mouse carcasses (but not chick carcasses) as surrogates for bats.

Parasitos gastrointestinais em cães e gatos em linha com a abordagem "Saúde Única”

ABSTRACT Dogs and cats are frequently affected by gastrointestinal parasites of medical and veterinary concern. The correct diagnosis is pivotal to the treatment outcome, reducing the risk of environmental contamination and spreading of these pathogens. The aim of this study was to determine the prevalence of gastrointestinal parasites of domiciled dogs and cats in an urban area of Northeastern Brazil, as well as to discuss the findings from a “One Health” perspective. Fecal samples (n = 231) of dogs (n = 126) and cats (n = 105) were obtained directly from the environment after spontaneous defecation, and subsequently analyzed through the Mini-FLOTAC and Baermann techniques. Of all samples, 28.14% (65/231) presented immature forms of gastrointestinal parasites, with 31.75% (40/126) and 23.81% (25/105) of dogs and cats positive, respectively (x 2 = 1.413; p = 0.2345). Two genera of helminths (Ancylostoma and Toxocara) and two genera of protozoa (Cystoisospora and Entamoeba) were identified. Additionally, co-infections were observed in 15% (6/40) of positive dogs and 28% (7/25) of positive cats (p = 0.2207). None metastrongyloid larvae were detected. In conclusion, animals herein assessed presented a high prevalence of zoonotic gastrointestinal nematodes. Therefore, preventive measures against these neglected parasites should be stimulated.

Kidney injury biomarkers and parasitic loads of Schistosoma mansoni in a highly endemic area in northeastern Brazil

Schistosomiasis affects approximately 240 million people worldwide. In Brazil, it is estimated that 1.5 million people are infected with Schistosoma mansoni and up to 15% of diagnosed individuals develop kidney damage. Renal involvement in schistosomiasis mansoni is characterized by glomerular lesions, with a high incidence, especially in chronically infected patients living in areas of high endemicity. Renal damage occurs slowly and is often asymptomatic, with a long-term manifestation of chronic kidney disease, with progressive loss of kidney functions, and early detection of subclinical kidney disease is of great importance. The aim of this study was to investigate kidney damage in patients infected with S. mansoni through urinary biomarkers of kidney injury and their association with the different parasite loads found. The patients were divided into two groups based on the diagnosis of infection by S. mansoni by the Kato-Katz and IgG-ELISA-SEA method: group of individuals infected by S. mansoni, Kato-Katz positive (PG); and group of individuals not infected by S. mansoni, Kato-Katz-negative (NG). Urinary creatinine and albuminuria were determined by immunoturbidimetry and proteinuria by the colorimetric method. The urinary biomarkers of podocyte injury (VEGF and Nephrin) and glomerular inflammation (MCP-1) were quantified by immunoassay and expressed by the urinary creatinine ratio. Urinary VEGF showed significantly higher levels in PG compared to NG (p = 0.004), increasing at all intensities of infection including low parasite load (p = 0.020). Our results show increased signs of podocyte damage in patients with schistosomiasis mansoni regardless of the parasite load, evidenced by increased urinary VEGF levels. However, further studies are needed since data related to schistosomiasis glomerulopathy and its association with new urinary biomarkers of kidney injury are scarce in the literature.

Parasitism by Bat Flies on Bats in Remnants of a Humid Forest Enclave Area in Northeastern Brazil

Parasitism by Bat Flies on Bats in Remnants of a Humid Forest Enclave Area in Northeastern Brazil

Assessment of Potential Human Health, Radiological and Ecological Risks Around Mining Areas in Northeastern Brazil

Assessment of Potential Human Health, Radiological and Ecological Risks Around Mining Areas in Northeastern Brazil

On-farm conservation in Phaseolus lunatus L: an alternative for agricultural biodiversity

ABSTRACT On-farm conservation characterized by cultivation by smallholder farmers in agricultural and quilombola (formed by descendants of Afro-Brazilian slaves) communities is a tool for the maintenance of seeds and genetic diversity. Smallholder farmers who grow local varieties in diversity centers and communities contribute to supporting the capacity of agricultural and food systems to adapt to adverse conditions. Widely cultivated in the Northeast region of Brazil, lima bean (Phaseolus lunatus L), despite having relative economic and social importance, is little exploited in terms of conservation aspects. Based on a process of participatory interview, this article documents the knowledge of smallholder farmers associated with local varieties of this species, as well as the practices and strategies used for on-farm conservation in three producing areas of northeastern Brazil. The results revealed that farmers have a low level of education; the main factor for the loss of traditional knowledge is the disinterest of younger people in agriculture. The study highlights the importance of integrating scientific knowledge with traditional knowledge to develop sustainable agroecosystems, in which on-farm conservation is an alternative to diversify agriculture, but which requires government and private support to stimulate and enhance agricultural activities and the interaction among smallholder farmers.

Intestinal polyparasitism and levels of mucosal anthelmintic SIgA in children from endemic areas in Northeastern Brazil.

Interactions between parasites during co-infections are often complex and can impact immunization and treatment programmes, as well as disease outcomes and morbidity. However, little is known about these interactions and the mechanisms involved. In this study, a coproparasitological survey was carried out in school-age children living in endemic areas of parasitic infection in the state of Sergipe, Northeastern Brazil. Anti-helminth-specific and total secretory immunoglobulin-A (SIgA) levels were measured in stool and saliva samples and were compared in children presenting monoparasitism, polyparasitism (helminths and/or intestinal protozoa) and no infections. The survey showed that protozoa were more prevalent than helminths, and that there was a high frequency of polyparasitism in the studied population, mainly from combinations of protozoan species. Although less frequent, combinations between species of protozoa and helminths were also observed. The levels of salivary SIgA in these co-infected individuals were lower than the average observed in infections with helminths alone. Although the children participating in this survey were asymptomatic, and it was, therefore, not possible to evaluate the impact of salivary SIgA reduction on the diseases, and the study highlights the need for further investigations of co-infections by intestinal parasites and the effects on immune response induced by the interactions between different parasites.