KARIN KIRCHGATTER
Projetos de Pesquisa
Unidades Organizacionais
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina - Líder
41 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 41
- Molecular Investigation Confirms Myotis Genus Bats as Common Hosts of Polychromophilus in Brazil(2023) MATHIAS, Bruno da Silva; MINOZZO, Guilherme Augusto; BIONDO, Alexander Welker; COSTA, Jaciara de Oliveira Jorge; SOARES, Herbert Sousa; MARCILI, Arlei; GUIMARAES, Lilian de Oliveira; ANJOS, Carolina Clares dos; SANTOS, Andrea Pires Dos; RIEDIGER, Irina Nastassja; FECCHIO, Alan; BUENO, Marina Galvao; PINHO, Joao Batista; KIRCHGATTER, KarinPlasmodium spp. and some other blood parasites belonging to the order Haemosporida are the focus of many epidemiological studies worldwide. However, haemosporidian parasites from wild animals are largely neglected in scientific research. For example, Polychromophilus parasites, which are exclusive to bats, are described in Europe, Asia, Africa, and Oceania, but little is known about their presence and genetic diversity in the New World. In this study, 224 samples of bats from remaining fragments of the Atlantic Forest and Pantanal biomes, as well as urbanized areas in southern and southeastern Brazil, were analyzed for the presence of haemosporidian parasites by PCR of the mitochondrial gene that encodes cytochrome b (cytb). The PCR fragments of the positive samples were sequenced and analyzed by the Bayesian inference method to reconstruct the phylogenetic relationships between Polychromophilus parasites from bats in Brazil and other countries. Sequences from Brazilian lineages of Polychromophilus were recovered in a clade with sequences from Polychromophilus murinus and close to the one Polychromophilus sequence obtained in Panama, the only available sequence for the American continent. This clade was restricted to bats of the family Vespertilionidae and distinct from Polychromophilus melanipherus, a parasite species mainly found in bats of the family Miniopteridae. The detection of Polychromophilus and the genetic proximity to P. murinus were further confirmed with the amplification of two other genes (clpc and asl). We also found a Haemosporida parasite sequence in a sample of Noctilio albiventris collected in the Pantanal biome, which presents phylogenetic proximity with avian Haemoproteus sequences. Morphological and molecular studies are still needed to conclude and describe the Polychromophilus species in Brazilian Myotis bats in more detail and to confirm Haemoproteus parasites in bats. Nevertheless, these molecular results in Brazilian bats confirm the importance of studying these neglected genera.
- Global drivers of avian haemosporidian infections vary across zoogeographical regions(2021) FECCHIO, Alan; CLARK, Nicholas J.; BELL, Jeffrey A.; SKEEN, Heather R.; LUTZ, Holly L.; TORRE, Gabriel M. De La; VAUGHAN, Jefferson A.; TKACH, Vasyl V.; SCHUNCK, Fabio; FERREIRA, Francisco C.; BRAGA, Erika M.; LUGARINI, Camile; WAMITI, Wanyoike; DISPOTO, Janice H.; GALEN, Spencer C.; KIRCHGATTER, Karin; SAGARIO, M. Cecilia; CUETO, Victor R.; GONZALEZ-ACUNA, Daniel; INUMARU, Mizue; SATO, Yukita; SCHUMM, Yvonne R.; QUILLFELDT, Petra; PELLEGRINO, Irene; DHARMARAJAN, Guha; GUPTA, Pooja; ROBIN, V. V.; CILOGLU, Arif; YILDIRIM, Alparslan; HUANG, Xi; CHAPA-VARGAS, Leonardo; ALVAREZ-MENDIZABAL, Paulina; SANTIAGO-ALARCON, Diego; V, Serguei Drovetski; HELLGREN, Olof; VOELKER, Gary; RICKLEFS, Robert E.; HACKETT, Shannon J.; COLLINS, Michael D.; WECKSTEIN, Jason D.; WELLS, KonstansAim Macroecological analyses provide valuable insights into factors that influence how parasites are distributed across space and among hosts. Amid large uncertainties that arise when generalizing from local and regional findings, hierarchical approaches applied to global datasets are required to determine whether drivers of parasite infection patterns vary across scales. We assessed global patterns of haemosporidian infections across a broad diversity of avian host clades and zoogeographical realms to depict hotspots of prevalence and to identify possible underlying drivers. Location Global. Time period 1994-2019. Major taxa studied Avian haemosporidian parasites (genera Plasmodium, Haemoproteus, Leucocytozoon and Parahaemoproteus). Methods We amalgamated infection data from 53,669 individual birds representing 2,445 species world-wide. Spatio-phylogenetic hierarchical Bayesian models were built to disentangle potential landscape, climatic and biotic drivers of infection probability while accounting for spatial context and avian host phylogenetic relationships. Results Idiosyncratic responses of the three most common haemosporidian genera to climate, habitat, host relatedness and host ecological traits indicated marked variation in host infection rates from local to global scales. Notably, host ecological drivers, such as migration distance for Plasmodium and Parahaemoproteus, exhibited predominantly varying or even opposite effects on infection rates across regions, whereas climatic effects on infection rates were more consistent across realms. Moreover, infections in some low-prevalence realms were disproportionately concentrated in a few local hotspots, suggesting that regional-scale variation in habitat and microclimate might influence transmission, in addition to global drivers. Main conclusions Our hierarchical global analysis supports regional-scale findings showing the synergistic effects of landscape, climate and host ecological traits on parasite transmission for a cosmopolitan and diverse group of avian parasites. Our results underscore the need to account for such interactions, in addition to possible variation in drivers across regions, to produce the robust inference required to predict changes in infection risk under future scenarios.
- First Molecular Detection of Polychromophilus Parasites in Brazilian Bat Species(2021) MINOZZO, Guilherme Augusto; MATHIAS, Bruno da Silva; RIEDIGER, Irina Nastassja; GUIMARAES, Lilian de Oliveira; ANJOS, Carolina Clares dos; MONTEIRO, Eliana Ferreira; SANTOS, Andrea Pires dos; BIONDO, Alexander Welker; KIRCHGATTER, KarinBlood parasites of the Haemosporida order, such as the Plasmodium spp. responsible for malaria, have become the focus of many studies in evolutionary biology. However, there is a lack of molecular investigation of haemosporidian parasites of wildlife, such as the genus Polychromophilus. Species of this neglected genus exclusively have been described in bats, mainly in Europe, Asia, and Africa, but little is known about its presence and genetic diversity on the American continent. Here, we investigated 406 bats from sites inserted in remnant fragments of the Atlantic Forest and Cerrado biomes and urbanized areas from southern Brazil for the presence of Polychromophilus species by PCR of the mitochondrial cytochrome b encoding gene. A total of 1.2% of bats was positive for Polychromophilus, providing the first molecular information of these parasites in Myotis riparius and Eptesicus diminutus, common vespertilionid bats widely distributed in different Brazilian biomes, and Myotis ruber, an endangered species. A Bayesian analysis was conducted to reconstruct the phylogenetic relationships between Polychromophilus recovered from Brazilian bats and those identified elsewhere. Sequences of Brazilian Polychromophilus lineages were placed with P. murinus and in a clade distinct from P. melanipherus, mainly restricted to bats in the family Vespertilionidae. However, the sequences were split into two minor clades, according to the genus of hosts, indicating that P. murinus and a distinct species may be circulating in Brazil. Morphological observations combined with additional molecular studies are needed to conclude and describe these Polychromophilus species.
- Infectious Diseases in Free-Ranging Blonde Capuchins, Sapajus flavius, in Brazil(2017) BUENO, Marina Galvao; CATO-DIAS, Jose Luiz; LAROQUE, Plautino de Oliveira; VASCONCELLOS, Silvio Arruda; FERREIRA NETO, Jose Soares; GENNARI, Solange Maria; FERREIRA, Fernando; LAURENTI, Marcia Dalastra; UMEZAWA, Eufrosina Setsu; KESPER, Norival; KIRCHGATTER, Karin; GUIMARES, Lilian Oliveira; PAVANATO, Heloise Juliao; VALENCA-MONTENEGRO, Monica MafraThe main threats to primates worldwide are the degradation, fragmentation, and loss of their habitats; hunting (especially for bushmeat); and illegal trade. For many species, the most important threat is forest fragmentation, resulting in small populations that are restricted to isolated forest patches. In this situation, primates are particularly vulnerable to disease. The Endangered blonde capuchin (Sapajus flavius) is now restricted to a few forest patches in Northeast Brazil. We investigated the occurrence of parasites and bacterial diseases in one of three free-ranging groups of S. flavius in a small forest patch in Paraiba state, Northeast Brazil. We tested for antibodies against Leishmania spp., Trypanosoma cruzi, Toxoplasma gondii, Leptospira spp. (24 strains), and Brucella spp.. We used molecular analysis to detect Plasmodium spp., and evaluated blood smears for the presence of hemoparasites. All individuals tested negative for Leptospira spp. and B. abortus, but 8 of 48 (16%) presented antibodies for both Leishmania spp. and T. cruzi. We identified antibodies to T. gondii in 12% of the individuals tested. Plasmodium brasilianum infection was present in 4% of the individuals tested, and blood smears showed microfilariae parasites in 46% of the individuals tested. The occurrence of these infectious diseases in S. flavius may pose a significant threat in terms of reduced recruitment and poor survival rates, and an understanding of the influence of pathogens is crucial for the management of small populations of primates.
- The recombinant LIC10508 is a plasma fibronectin, plasminogen, fibrinogen and C4BP-binding protein of Leptospira interrogans(2016) SIQUEIRA, Gabriela H.; TEIXEIRA, Aline F.; FERNANDES, Luis G.; SOUZA, Gisele O. de; KIRCHGATTER, Karin; ROMERO, Eliete C.; VASCONCELLOS, Silvio A.; VIEIRA, Monica L.; NASCIMENTO, Ana Lucia T. O.Leptospirosis is a zoonosis caused by pathogenic Leptospira spp. In this study, we report that the recombinant proteins LIC10507, LIC10508 and LIC10509 are recognized by confirmed leptospirosis serum samples at both phases of the disease. The recombinant rLIC10508 and rLIC10507 are plasminogen (PLG)-binding proteins, capable of generating plasmin in the presence of a PLG activator. The proteins bind to PLG in a dose-dependent and saturable manner, fulfilling host-ligand interaction. Furthermore, rLIC10508 interacts with fibrinogen (Fg), plasma fibronectin and C4b binding protein (C4BP). The binding of rLIC10508 to Fg decreases the fibrin clotting in a thrombin-catalyzed reaction. The incubation with 4 mu M of protein promoted 40% inhibition upon clotting formation. C4BP bound to rLIC10508 retained its cofactor activity for factor I promoting the cleavage of C4b protein, which may reduce the membrane attack complex formation. Although these proteins have high amino acid sequence similarity, rLIC10508 is the most talented of the three, a behavior that might be explained by its unique putative 3D structure, whereas structures of rLIC10507 and rLIC10509 are very similar. Plasmin generation (rLIC10507 and rLIC10508), together with decreasing fibrin clot formation (rLIC10508) and impairment of the complement system (rLIC10508) may help the bacteria to overcome host defense, facilitating the infection process.
- Detection of Reticuloendotheliosis Virus in Muscovy Ducks, Wild Turkeys, and Chickens in Brazil(2020) CALEIRO, Giovana S.; NUNES, Cristina F.; URBANO, Paulo R.; KIRCHGATTER, Karin; ARAUJO, Jansen de; DURIGON, Edison Luiz; THOMAZELLI, Luciano M.; STEWART, Brittany M.; EDWARDS, Dustin C.; ROMANO, Camila M.Reticuloendotheliosis viruses (REVs) are known to cause immunosuppressive and oncogenic disease that affects numerous avian species. Reticuloendotheliosis viruses are present worldwide and recently have been reported in South America with cases of infected commercial flocks in Argentina. We surveyed for the presence of REV in birds from a state in the northern region of Brazil using real-time PCR. We report here the presence of REV in Brazil, detected in Muscovy Ducks (Cairina moschata), Wild Turkeys (Meleagris gallopavo), and chickens (Gallus gallus) at a relatively high prevalence (16.8%). Phylogenetic analysis indicated a close relationship of these strains to variants in the US. This study provides evidence of REV in the Amazon biome and provides a baseline for future surveillance of the virus in the region and throughout Brazil.
- The interaction of two novel putative proteins of Leptospira interrogans with E-cadherin, plasminogen and complement components with potential role in bacterial infection(2019) KOCHI, Leandro T.; V, Luis G. Fernandes; SOUZA, Gisele O.; VASCONCELLOS, Silvio A.; HEINEMANN, Marcos B.; ROMERO, Eliete C.; KIRCHGATTER, Karin; NASCIMENTO, Ana L. T. O.Leptospirosis is a worldwide zoonosis caused by pathogenic species of Leptospira. Leptospires are able to adhere to exposed extracellular matrix in injured tissues and, once in the bloodstream, can survive the attack of the immune system and spread to colonize target organs. In this work, we report that two novel putative proteins, coded by the genes LIC11711 and LIC12587 of L. interrogans serovar Copenhageni are conserved among pathogenic strains, and probably exposed in the bacterial surface. Soluble recombinant proteins were expressed in Escherichia coli, purified and characterized. Both recombinant proteins bound to laminin and E-cadherin, suggesting an initial adhesion function in host epithelial cells. The recombinant protein LIC11711 (rLIC11711) was able to capture plasminogen (PLG) from normal human serum and convert to enzymatically active plasmin (PLA), in the presence of PLG activator. rLIC12587 (recombinant protein LIC12587) displayed a dose dependent and saturable interaction with components C7, C8, and C9 of the complement system, reducing the bactericidal effect of the complement. Binding to C9 may have consequences such as C9 polymerization inhibition, interfering with the membrane attack complex formation. Blocking LIC11711 and LIC12587 on bacterial cells by the respective antiserum reduced leptospiral cell viability when exposed to normal human serum (NHS). Both recombinant proteins could be recognized by serum samples of confirmed leptospirosis, but not of unrelated diseases, suggesting that the native proteins are immunogenic and expressed during leptospirosis. Taken together, our data suggest that these proteins may have a role in leptospiral pathogenesis, participating in immune evasion strategies.
- Avian Malaria and Related Parasites from Resident and Migratory Birds in the Brazilian Atlantic Forest, with Description of a New Haemoproteus Species(2021) ANJOS, Carolina C.; CHAGAS, Carolina R. F.; FECCHIO, Alan; SCHUNCK, Fabio; COSTA-NASCIMENTO, Maria J.; MONTEIRO, Eliana F.; MATHIAS, Bruno S.; BELL, Jeffrey A.; GUIMARAES, Lilian O.; COMICHE, Kiba J. M.; VALKIUNAS, Gediminas; KIRCHGATTER, KarinDetermining the prevalence and local transmission dynamics of parasitic organisms are necessary to understand the ability of parasites to persist in host populations and disperse across regions, yet local transmission dynamics, diversity, and distribution of haemosporidian parasites remain poorly understood. We studied the prevalence, diversity, and distributions of avian haemosporidian parasites of the genera Plasmodium, Haemoproteus, and Leucocytozoon among resident and migratory birds in Serra do Mar, Brazil. Using 399 blood samples from 66 Atlantic Forest bird species, we determined the prevalence and molecular diversity of these pathogens across avian host species and described a new species of Haemoproteus. Our molecular and morphological study also revealed that migratory species were infected more than residents. However, vector infective stages (gametocytes) of Leucocytozoon spp., the most prevalent parasites found in the most abundant migrating host species in Serra do Mar (Elaenia albiceps), were not seen in blood films of local birds suggesting that this long-distance Austral migrant can disperse Leucocytozoon parasite lineages from Patagonia to the Atlantic Forest, but lineage sharing among resident species and local transmission cannot occur in this part of Brazil. Our study demonstrates that migratory species may harbor a higher diversity and prevalence of parasites than resident species, but transportation of some parasites by migratory hosts may not always affect local transmission.
- Recombinant proteins of Plasmodium malariae merozoite surface protein 1 (PmMSP1): Testing immunogenicity in the BALB/c model and potential use as diagnostic tool(2019) ELIZARDEZ, Yelina B.; FOTORAN, Wesley L.; GALISTEO JUNIOR, Andre S. J.; CURADO, Izilda; KESPER JUNIOR, Norival; MONTEIRO, Eliana F.; NETO, Irineu Romero; WUNDERLICH, Gerhard; KIRCHGATTER, KarinBackground Plasmodium malariae is the third most prevalent human malaria-causing species and has a patchy, but ample distribution in the world. Humans can host the parasite for years without presenting significant symptoms, turning its diagnosis and control into a difficult task. Here, we investigated the immunogenicity of recombinant proteins of P. malariae MSP1. Methods Five regions of PmMSP1 were expressed in Escherichia coli as GST-fusion proteins and immunized in BALB/c mice. The specificity, subtyping, and affinity of raised antibodies were evaluated by enzyme-linked immunosorbent assays. Cellular immune responses were analyzed by lymphoproliferation assays and cytokine levels produced by splenocytes were detected by cytometry. Results We found that N-terminal, central regions, and PmMSP1(19) are strongly immunogenic in mice. After three doses, the induced immune responses remained high for 70 days. While antibodies induced after immunization with N-terminal and central regions showed similar affinities to the target antigens, affinities of IgG against PmMSP1(19) were higher. All proteins induced similar antibody subclass patterns (predominantly IgG1, IgG2a, and IgG2b), characterizing a mixed Th1/Th2 response. Further, autologous stimulation of splenocytes from immunized mice led to the secretion of IL2 and IL4, independently of the antigen used. Importantly, IgG from P. malariae-exposed individuals reacted against PmMSP1 recombinant proteins with a high specificity. On the other hand, sera from P. vivax or P. falciparum-infected individuals did not react at all against recombinant PmMSP1 proteins. Conclusion Recombinant PmMSP1 proteins are very useful diagnostic markers of P. malariae in epidemiological studies or in the differential diagnosis of malaria caused by this species. Immunization with recombinant PmMSP1 proteins resulted in a significant humoral immune response, which may turn them potential component candidates for a vaccine against P. malariae.
- Diversity and distribution of avian malaria and related haemosporidian parasites in captive birds from a Brazilian megalopolis(2017) CHAGAS, Carolina Romeiro Fernandes; VALKIUNAS, Gediminas; GUIMARAES, Lilian de Oliveira; MONTEIRO, Eliana Ferreira; GUIDA, Fernanda Junqueira Vaz; SIMOES, Roseli Franca; RODRIGUES, Priscila Thihara; LUNA, Expedito Jose de Albuquerque; KIRCHGATTER, KarinBackground: The role of zoos in conservation programmes has increased significantly in last decades, and the health of captive animals is essential to guarantee success of such programmes. However, zoo birds suffer from parasitic infections, which often are caused by malaria parasites and related haemosporidians. Studies determining the occurrence and diversity of these parasites, aiming better understanding infection influence on fitness of captive birds, are limited. Methods: In 2011-2015, the prevalence and diversity of Plasmodium spp. and Haemoproteus spp. was examined in blood samples of 677 captive birds from the Sao Paulo Zoo, the largest zoo in Latin America. Molecular and microscopic diagnostic methods were used in parallel to detect and identify these infections. Results: The overall prevalence of haemosporidians was 12.6%. Parasites were mostly detected by the molecular diagnosis, indicating that many birds harbour subclinical or abortive infections. In this project, birds of 17 orders (almost half of all the orders currently accepted in taxonomy of birds), 29 families, and 122 species, were tested, detecting positive individuals in 27% of bird species. Birds from the Anatidae were the most prevalently infected (64.7% of all infected animals). In all, infections with parasites of the genus Plasmodium (overall prevalence 97.6%) predominated when compared to those of the genus Haemoproteus (2.4%). In total, 14 cytochrome b (cytb) lineages of Plasmodium spp. and 2 cytb lineages of Haemoproteus spp. were recorded. Eight lineages were new. One of the reported lineages was broad generalist while others were reported in single or a few species of birds. Molecular characterization of Haemoproteus ortalidum was developed. Conclusion: This study shows that many species of birds are at risk in captivity. It is difficult to stop haemosporidian parasite transmission in zoos, but is possible to reduce the infection rate by treating the infected animals or/and while keeping them in facilities free from mosquitoes. Protocols of quarantine should be implemented whenever an animal is transferred between bird maintaining institutions. This is the first survey of haemosporidians in captive birds from different orders maintained in zoos. It is worth emphasizing the necessity of applying practices to control these parasites in management and husbandry of animals in captivity.