Explore the vast range of titles available.

Background Leptospirosis is caused by pathogenic spirochetes of the genus Leptospira spp. This zoonotic disease is distributed globally and affects domestic animals, including cattle. Leptospira interrogans serogroup Sejroe serovar Hardjo and Leptospira borgpetersenii serogroup Sejroe serovar Hardjo remain important species associated with this reproductive disease in livestock production. Previous studies on Brazilian livestock have reported that L. interrogans serovar Hardjo is the most prevalent leptospiral agent in this country and is related to clinical signs of leptospirosis, which lead to economic losses in production. Here, we described the isolation of three clinical strains (Norma, Lagoa and Bolivia) obtained from leptospirosis outbreaks that occurred in Minas Gerais state in 1994 and 2008. Results Serological and molecular typing using housekeeping ( secY and 16SrRNA) and rfb locus (ORF22 and ORF36) genes were applied for the identification and comparative analysis of Leptospira spp. Our results identified the three isolates as L. interrogans serogroup Sejroe serovar Hardjo and confirmed the occurrence of this bacterial strain in Brazilian livestock. Genetic analysis using ORF22 and ORF36 grouped the Leptospira into serogroup Sejroe and subtype Hardjoprajitno. Genetic approaches were also applied to compare distinct serovars of L. interrogans strains by verifying the copy numbers of the IS1500 and IS1533 insertion sequences (ISs). The IS1500 copy number varied among the analyzed L. interrogans strains. Conclusion This study provides evidence that L. interrogans serogroup Sejroe serovar Hardjo subtype Hardjoprajitno causes bovine leptospirosis in Brazilian production. The molecular results suggested that rfb locus (ORF22 and ORF36) could improve epidemiological studies by allowing the identification of Leptospira spp. at the serogroup level. Additionally, the IS1500 and IS1533 IS copy number analysis suggested distinct genomic features among closely related leptospiral strains.

Background The presence of lymphoma in buffaloes was first reported in India in the 1960s. The disease is similar to Enzootic Bovine Leucosis (EBL) caused by Bovine leukemia virus (BLV) in cattle; however, according to our results and those of other studies, the etiology of these lymphomas in buffalo do not appear to be associated with BLV. The objectives of this study are to describe four cases of the disease in buffaloes belonging to the same herd in the Amazon region of Brazil and to perform a clinical-anatomopathological, immunohistochemical, and etiological study of the lymphomas. Results Over a period of ten years, four buffaloes were observed presenting progressive weight loss, swelling of peripheral lymph nodes, and nodules in the subcutaneous tissue. Upon necropsy, whitish-colored tumor masses were observed in the form of nodules in the subcutaneous tissue, along with miliary nodules on the serosal surfaces of abdominal and thoracic organs and tumors in lymph nodes and other organs. Neoplastic lymphocyte proliferation was observed through histopathology. An immunohistochemical study revealed that the neoplasias were formed by proliferation of predominantly B lymphocytes. The presence of BLV genome was not detected in the lymphomas when using the real-time PCR technique, nor was it detected through immunohistochemical staining using monoclonal antibodies against two viral proteins. Bovine herpesvirus 6 was not detected in the tumors. However, Bovine immunodeficiency virus (BIV) was detected in samples of lymphoma and in the lymph nodes and kidneys of one of the animals. Conclusions The occurrence of lymphoma in buffaloes is reported for the first time in Brazil and is characterized by B-cell multicentric lymphoma. The etiology of the disease does not appear to be associated with BLV; however, the detection of BIV in samples of lymphoma from one sick animal deserves further study, considering the oncogenic potential of this virus.

Background The White spot syndrome virus (WSSV) and Penaeus stylirostris penstyldensovirus 1 (previously named Infectious hypodermal and hematopoietic necrosis virus -IHHNV) are two of the most important viral pathogens of penaeid shrimp. Different methods have been applied for diagnosis of these viruses, including Real-time PCR (qPCR) assays. A duplex qPCR method allows the simultaneous detection of two viruses in the same sample, which is more cost-effective than assaying for each virus separately. Currently, an assay for the simultaneous detection of the WSSV and the PstDV1 in shrimp is unavailable. The aim of this study was to develop and standardize a duplex qPCR assay for the simultaneous detection of the WSSV and the PstDV1 in clinical samples of diseased L. vannamei . In addition, to evaluate the performance of two qPCR master mixes with regard to the clinical sensitivity of the qPCR assay, as well as, different methods for qPCR results evaluation. Results The duplex qPCR assay for detecting WSSV and PstDV1 in clinical samples was successfully standardized. No difference in the amplification of the standard curves was observed between the duplex and singleplex assays. Specificities and sensitivities similar to those of the singleplex assays were obtained using the optimized duplex qPCR. The analytical sensitivities of duplex qPCR were two copies of WSSV control plasmid and 20 copies of PstDV1 control plasmid. The standardized duplex qPCR confirmed the presence of viral DNA in 28 from 43 samples tested. There was no difference for WSSV detection using the two kits and the distinct methods for qPCR results evaluation. High clinical sensitivity for PstDV1 was obtained with TaqMan Universal Master Mix associated with relative threshold evaluation. Three cases of simultaneous infection by the WSSV and the PstDV1 were identified with duplex qPCR. Conclusion The standardized duplex qPCR was shown to be a robust, highly sensitive, and feasible diagnostic tool for the simultaneous detection of the WSSV and the PstDV1 in whiteleg shrimp. The use of the TaqMan Universal Master Mix and the relative threshold method of data analysis in our duplex qPCR method provided optimal levels of sensitivity and specificity.

Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV) induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi), by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control.

To define the prevalence of anti-Leptospira sp. agglutinins in ewes in the Federal District, Brazil, serum samples from 157 ewes were tested for antibodies against serovars of Leptospira sp. by the microscopic agglutination test. Antibodies were detected in three flocks in a prevalence of 3% (95% CI = 0.4%-5.7%). Considering that sheep and cattle were raised together, the lack of sanitary control could represent a risk to cattle production, which is the most important activity in the Centre-West region of Brazil.

AbstractLeptospirosis is a zoonotic disease caused by pathogenic spirochetes of the genus Leptospira. It has a global distribution and affects domestic animals, including cattle. In livestock production, Leptospira interrogans serogroup Sejroe serovar Hardjo is the major reproductive disease leading to economic losses. The whole-genome sequence of the first Brazilian clinical isolate classified as L. interrogans serogroup Sejroe serovar Hardjo strain Norma enabled the evaluation of its genomic features. Here, we investigated particularities of this isolate, obtained from a leptospirosis outbreak. Bioinformatic analysis using the L. interrogans serovar Hardjo str. Norma was applied as a reference for genomic evaluation and comparative analysis among L. interrogans and L. borgpetersenii serovars. Our data suggest the occurrence of genomic recombination in L. interrogans serovar Hardjo str. Norma encompassing 45 Kb located upstream of the rfb locus. A hallmark of genetic evolution was predicted through an orthologue analysis that identified that sugar enzymes associated with carbohydrate and lipid biosynthesis and metabolism composed this genetic module. Comparative genomics revealed a wide range of relatedness among the bacterial strains of serogroup Sejroe that are classified as L. interrogans and L. borgpetersenii species. Furthermore, identification of an IS3 family suggests a genetic recombination site in L. interrogans serovar Hardjo str. Norma that is distinct among L. interrogans serovars and may contribute to clarify the taxonomic classification of Leptospira spp.Impact Statement Leptospirosis remains an important neglected disease with worldwide distribution. This zoonotic disease impacts in the livestock production and the bovine infection is currently associated to species L. borgpetersenii and L. interrogans serovar Hardjo. L.interrogans serovar Hardjo infection is recognized as reproductive disease associated with abortion and economic lost. In this context, we studied a unique whole genome sequence of L. interrogans serovar Hardjo subtype Hardjo-prajitno isolated from bovine leptospirosis outbreaks in Brazilian dairy farm, one of the greatest country of milk production in world. We compared L. interrogans and L. borgpetersenii genomes with L. interrogans serogroup Sejroe serovar Hardjo subtype Hardjo-prajitno focusing on rfb locus and sugars biosynthesis. Leptospira spp. taxonomy and serology information are strictly associated with rfb locus and we found high correlation among bacterial strains classified in serogroup Sejroe. Although L. interrogans and L. borgpetersenii classified in serogroup Sejroe possess a greater genetic correlation, we uniquely identified that serovar Hardjo strains often possess identical loci carrying predicted sugar biossinthesis genes and mobile elements. The Sru (Sejroe specific Rfb Upstream locus) locus associated to rfb locus probably contribute to Leptospira spp. genetic information concerning serogroup and serovar degrees of taxonomic and serology in this microbiology field.Data Summary All Leptospira spp. genome sequences used in this study were retrieved from National Center for Biotechnology Information (NCBI) (Table 1) with NCBI ID: NZ_CP006723.1, NZ_CP012603.1, NC_004342.2, NZ_CP011934.1, NZ_AKXA02000040.1, NZ_CP013147.1, NZ_CP012029.1, NZ_CP015048.1, NC_008508.1, GCA_000216175.3,GCA_000244115.3, NC005823.1, GCA_000244395.3, GCA_000346975.1.Highlights1. The study identified potential molecular features associated with serovar Hardjo subtype Hardjo-prajitno, present in both L. interrogans and L. borgpetersenii, by comparative genomics.2. A new potential recombinant site found upstream of the rfb locus contains proteins that correlate with serogroup taxonomy in the Leptospira genus.3. The proteins encoded in the recombinant locus are associated with the synthesis of serological surface determinants such as carbohydrates and lipopolysaccharides.

A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported \"color\", but several studies have demonstrated that stratifying according to \"color\" is not a useful strategy to control for population structure, due to the dissociation between self-reported \"color\" and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs). Self-reported \"color\", according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported \"color\" and skin pigmentation, self-reported \"color\" and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three \"color\" groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the \"color\" categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different \"color\", and in some cases, the sibling reporting the darker \"color\" category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported \"color\" and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported \"color\", such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654), which is located in the known pigmentation gene SLC24A5, was strongly associated with skin pigmentation in this sample.

The effect of topical application of ointment based on Strychnos pseudoquina hydroethanolic extract in the cutaneous wounds healing in diabetic rats was evaluated. Samples of S. pseudoquina were submitted to phytochemical prospection and in vitro antioxidant assay. Thirty Wistar rats were divided into 5 groups: Sal-wounds treated with 0.9% saline solution; VH-wounds treated with 0.6 g of lanolin cream (vehicle); SS-wounds treated with silver sulfadiazine cream (10 mg/g); ES5- and ES10-wounds treated with an ointment of S. pseudoquina extract, 5% and 10%, respectively. Fragments of wounds were removed for histological and biochemical analysis every 7 days during 21 days. ES showed equivalent levels per gram of extract of total phenols and flavonoids equal to 122.04 mg for TAE and 0.60 mg for RE. The chlorogenic acid was one of the major constituents. S. pseudoquina extract presented high antioxidant potential in vitro. ES5 and ES10 showed higher wound healing rate and higher amount of cells, blood vessels, and type III and I collagen. The oxidative stress markers were lower in the ES5 and ES10 groups, while the antioxidants enzymes levels were higher. Ointment based on S. pseudoquina extract promotes a fast and efficient cutaneous repair in diabetic rats.

Tropical Dry Forests (TDFs) have been broadly converted into pastures and crops, with direct consequences to biodiversity, ecosystem services, and social welfare. Such land use and cover changes (LUCC) usually are strongly influenced by government environmental and development policies. The present study aimed at analyzing LUCC in Brazilian TDFs between 2000 and 2015, using the north of Minas Gerais state (128 000 km2) as a case study. We evaluated the potential biophysical and social-economic drivers of TDF loss, natural regeneration and net area change at the county level. Further, we determined the effects of these LUCC variables on socioeconomic indicators. We identified a considerable change in TDF cover, expressed as 9825 km2 of deforestation and 6523 km2 of regeneration, which resulted in a net loss of 3302 km2. The annual rate of TDF cover change was −1.2%, which is extremely high for a vegetation type that is protected as part of the Atlantic Rain Forest biome since 1993. TDF deforestation was directly affected by county area and by the increase in cattle density, and inversely affected by terrain declivity, indicating that land conversion is mostly driven by cattle ranching in flat regions. TDF regeneration was directly affected by county area and inversely affected by the increase in population density and terrain declivity. LUCC variables did not affect welfare indicators, undermining claims from rural sectors that TDF protection would cause a socioeconomic burden for northern Minas Gerais. Our results highlight the importance of naturally regenerating secondary forests to the maintenance of ecosystem integrity and its services, which are frequently neglected in conservation strategies. Hegemonic macroeconomic policies affecting TDFs have been deeply rooted in deforestation for commodities production, and need urgent review because they cause long-term environmental impacts without evidence of welfare gains.

Clearing tropical vegetation impacts biodiversity, the provision of ecosystem services, and thus ultimately human welfare. We quantified changes in land cover from 2000 to 2015 across the Cerrado biome of northern Minas Gerais state, Brazil. We assessed the potential biophysical and socio-economic drivers of the loss of Cerrado, natural regeneration and net cover change at the municipality level. Further, we evaluated correlations between these land change variables and indicators of human welfare. We detected extensive land-cover changes in the study area, with the conversion of 23 446 km2 and the natural regeneration of 13 926 km2, resulting in a net loss of 9520 km2. The annual net loss (−1.2% per year) of the cover of Cerrado is higher than that reported for the whole biome in similar periods. We argue that environmental and economic variables interact to underpin rates of conversion of Cerrado, most severely affecting more humid Cerrado lowlands. While rates of Cerrado regeneration are important for conservation strategies of the remaining biome, their integrity must be investigated given the likelihood of encroachment. Given the high frequency of land abandonment in tropical regions, secondary vegetation is fundamental to maintain biodiversity and ecosystem services. Finally, the impacts of Cerrado conversion on human welfare likely vary from local to regional scales, making it difficult to elaborate land-use policies based solely on socio-economic indicators. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’.