The genome of the zoonotic malaria parasite Plasmodium simium reveals adaptations to host switching

BACKGROUND: Plasmodium simium, a malaria parasite of non-human primates (NHP), was recently shown to cause zoonotic infections in humans in Brazil. We sequenced the P. simium genome to investigate its evolutionary history and to identify any genetic adaptions that may underlie the ability of this parasite to switch between host species. RESULTS: Phylogenetic analyses based on whole genome sequences of P. simium from humans and NHPs reveals that P. simium is monophyletic within the broader diversity of South American Plasmodium vivax, suggesting P. simium first infected NHPs as a result of a host switch of P. vivax from humans. The P. simium isolates show the closest relationship to Mexican P. vivax isolates. Analysis of erythrocyte invasion genes reveals differences between P. vivax and P. simium, including large deletions in the Duffy-binding protein 1 (DBP1) and reticulocyte-binding protein 2a genes of P. simium. Analysis of P. simium isolated from NHPs and humans revealed a deletion of 38 amino acids in DBP1 present in all human-derived isolates, whereas NHP isolates were multi-allelic. CONCLUSIONS: Analysis of the P. simium genome confirmed a close phylogenetic relationship between P. simium and P. vivax, and suggests a very recent American origin for P. simium. The presence of the DBP1 deletion in all human-derived isolates tested suggests that this deletion, in combination with other genetic changes in P. simium, may facilitate the invasion of human red blood cells and may explain, at least in part, the basis of the recent zoonotic infections

Neotropical Sylvatic Mosquitoes and <i>Aedes aegypti</i> Are Not Competent to Transmit 17DD Attenuated Yellow Fever Virus from Vaccinated Viremic New World Non-Human Primates

Beside humans, thousands of non-human primates (NHPs) died during the recent outbreak caused by the yellow fever virus (YFV) in Brazil. Vaccination of NHPs against YFV with the YF 17DD attenuated virus has emerged as a public health strategy, as it would reduce sylvatic transmission while also preserving endangered susceptible species. The hypothesis of establishing an uncontrolled transmission of this attenuated virus in nature was raised. We assessed vector competence of four sylvatic mosquito species, Haemagogus leucocelaenus, Haemagogus janthinomys/capricornii, Sabethes albiprivus, and Sabethes identicus, as well as the urban vector Aedes aegypti for YF 17DD attenuated vaccine virus when fed directly on eleven viremic lion tamarins or artificially challenged with the same virus. No infection was detected in 689 mosquitoes engorged on viremic lion tamarins whose viremia ranged from 1.05 × 103 to 6.61 × 103 FFU/mL, nor in those artificially taking ≤ 1 × 103 PFU/mL. Low viremia presented by YF 17DD-vaccinated New World NHPs combined with the low capacity and null dissemination ability in sylvatic and domestic mosquitoes of this attenuated virus suggest no risk of its transmission in nature. Thus, vaccination of captive and free-living NHPs against YFV is a safe public health strategy

Bioquímica plasmática de cascavéis (Caudisona durissa LINNAEUS, 1758) em cativeiro Blood biochemical parameters from captivity rattlesnake (Caudisona durissa LINNAEUS, 1758)

Acidentes com seres humanos envolvendo a espécie Caudisona durissa possuem a mais alta taxa de letalidade dentre os viperídeos brasileiros. Ressalta-se então a importância para a saúde pública da criação dessa espécie em cativeiro para produção de soro antiofídico. No entanto, essa atividade ainda hoje encontra alguns desafios como a instalação de doenças no plantel, evidenciando a importância de estudos sobre a fisiologia de serpentes. Dessa forma, foram realizadas análises de bioquímica plasmática em 53 serpentes da espécie Caudisona durissa, mantidas em cativeiro. Foram utilizadas amostras de plasma com heparina e as dosagens bioquímicas realizadas em aparelho automatizado (Ciba Corning - Express Plus®). Os resultados e seus respectivos desvios-padrões foram: uréia -1,32mg dL-1 (&plusmn;1,1); ácido úrico - 2,08mg dL-1 (&plusmn;1,4); creatinina - 0,52mg dL-1 (&plusmn;0,2); proteína total - 3,7g dL-1 (&plusmn;0,7); albumina - 1,62g dL-1 (&plusmn;0,4); globulinas - 2,08g dL-1 (&plusmn;0,5); cálcio - 15,25mg dL-1 (&plusmn;2,8); fósforo - 4,61mg dL-1 (&plusmn;1,9); colesterol - 171,58mg dL-1 (&plusmn;52,7); triglicerídeos - 19,29mg dL-1 (&plusmn;14,3); fosfatase alcalina - 31,04U L-1 (&plusmn;12,4); aspartato aminotransferase (AST) - 22,25U L-1 (&plusmn;11,4); alanina aminotransferase (ALT) - 7,11U L-1 (&plusmn;5,4) e Amilase - 1385,23U L-1 (&plusmn;568,7). Foram calculados os seguintes índices: relação uréia/creatinina - 2,5 e relação cálcio/fósforo - 3,3. O conjunto de resultados das análises bioquímicas do sangue das cascavéis em cativeiro pode servir como referência para apoio diagnóstico na espécie estudada e para outros trabalhos com o mesmo caráter de observação.<br>Human accidents involving rattlesnake Caudisona durissa have the highest fatality rate among the Brazilian Viperidae family. Breeding this specie in captivity in order to produce antivenoms is very important to public health. Nevertheless, there are some challenges that this activity must face, like the onset of diseases on the breeding stock, justifying the importance of studying these snakes' physiology. Blood biochemical analysis of 53 Caudisona durissa was performed using plasma samples in an automated equipment (Ciba Corning - Express Plus®). Mean values and its respective Standard deviations are: blood urea nitrogen (BUN) -1.32mg dL-1 (&plusmn;1.1); uric acid - 2.08mg dL-1 (&plusmn;1.4); creatinine - 0.52mg dL-1 (&plusmn;0.2); total protein - 3.7g dL-1 (&plusmn;0.7); albumin - 1.62g dL-1 (&plusmn;0.4); globulins - 2.08g dL-1 (&plusmn;0.5); calcium - 15.25mg dL-1 (&plusmn;2.8); phosphorus - 4.61mg dL-1 (&plusmn;1.9); cholesterol - 171.58mg dL-1 (&plusmn;52.7); triglycerides - 19.29mg dL-1 (&plusmn;14.3); alkaline phosfatase - 31.04U L-1 (&plusmn;12.4); aspartate aminotransferase (AST) - 22.25U L-1 (&plusmn;11.4); alanin aminotransferase (ALT) 7.11U L-1 (&plusmn;5.4); amylases - 1385.23U L-1 (&plusmn;568.7). The following indexes were calculated: BUN/creatinine ratio - 2.5 and calcium/phosphorus ratio -3.3. Rattlesnake blood biochemical results above could be used as reference in clinical evaluation for captivity C. durissa

IgM antibody responses against Plasmodium antigens in neotropical primates in the Brazilian Atlantic Forest

IntroductionZoonotic transmission is a challenge for the control and elimination of malaria. It has been recorded in the Atlantic Forest, outside the Amazon which is the endemic region in Brazil. However, only very few studies have assessed the antibody response, especially of IgM antibodies, in Neotropical primates (NP). Therefore, in order to contribute to a better understanding of the immune response in different hosts and facilitate the identification of potential reservoirs, in this study, naturally acquired IgM antibody responses against Plasmodium antigens were evaluated, for the first time, in NP from the Atlantic Forest.MethodsThe study was carried out using 154 NP samples from three different areas of the Atlantic Forest. IgM antibodies against peptides of the circumsporozoite protein (CSP) from different Plasmodium species and different erythrocytic stage antigens were detected by ELISA.ResultsFifty-nine percent of NP had IgM antibodies against at least one CSP peptide and 87% against at least one Plasmodium vivax erythrocytic stage antigen. Levels of antibodies against PvAMA-1 were the highest compared to the other antigens. All families of NP showed IgM antibodies against CSP peptides, and, most strikingly, against erythrocytic stage antigens. Generalized linear models demonstrated that IgM positivity against PvCSP and PvAMA-1 was associated with PCR-detectable blood-stage malaria infection and the host being free-living. Interestingly, animals with IgM against both PvCSP and PvAMA-1 were 4.7 times more likely to be PCR positive than animals that did not have IgM for these two antigens simultaneously.DiscussionIgM antibodies against different Plasmodium spp. antigens are present in NP from the Atlantic Forest. High seroprevalence and antibody levels against blood-stage antigens were observed, which had a significant association with molecular evidence of infection. IgM antibodies against CSP and AMA-1 may be used as a potential marker for the identification of NP infected with Plasmodium, which are reservoirs of malaria in the Brazilian Atlantic Forest

Avaliação da resposta inflamatória hematológica em cascavéis (Crotalus durissus Linnaeus, 1758) inoculadas com BCG Assessment of blood inflammatory response in BCG stimulated rattlesnakes (Crotalus durissus Linnaeus, 1758)

A criação de serpentes peçonhentas em cativeiro para produção de soros antipeçonhas possui crescente importância para a saúde pública devido ao aumento do número de notificações de acidentes ofídicos a cada ano no Brasil. Iniciado no século XX, ainda hoje essa atividade apresenta alguns desafios como a instalação de doenças no plantel. O hemograma é um exame de triagem clínica que auxilia no diagnóstico de diversas moléstias que acometem diferentes espécies de animais, no entanto ainda pouco estudado em serpentes. A caracterização das alterações hematológicas em cascavéis inoculadas experimentalmente com BCG pode servir de base na utilização deste exame no auxílio ao diagnóstico de infecções bacterianas na espécie. Dessa forma, foram realizados exames hematológicos em 10 serpentes da espécie Crotalus durissus pertencentes ao plantel da Divisão de Herpetologia do Instituto Vital Brazil. Os animais foram divididos em dois grupos (Grupos 1 e 2), homogêneos entre si em relação ao peso e proporção sexual. Os dois grupos foram inoculados com BCG e submetidos à coleta de sangue antes da inoculação e em três momentos pós-inoculação (3º, 5º, e 7º dias para o Grupo 1 e 11º, 17º e 21º dias para o Grupo 2). O hemograma foi realizado por método semidireto pela utilização de líquido de Natt e Herrick e as lâminas foram coradas pelo Giemsa. Observou-se anemia discreta, com redução dos valores de concentração de hemoglobina corpuscular média e da hemoglobina globular média no Grupo 1 que foi relacionada à doença inflamatória. A trombocitopenia observada no Grupo 2 sugeriu a atuação deste tipo celular em processos inflamatórios. Um único animal do Grupo 1 apresentou granulocitose e alguns animais apresentaram discreta azurofilia. Observaram-se alterações morfológicas nos leucócitos. Os granulócitos apresentaram granulações grosseiras e os azurófilos apresentaram aumento de tamanho e grandes vacúolos. De forma geral, a inoculação de BCG em cascavéis desencadeia respostas inflamatórias hematológicas caracterizadas pela participação de trombócitos, granulócitos e azurófilos.<br>The high demand for anti-venom production in response to the increased number of cases of snakebite envenomation highlights the importance of raising and breeding venomous snakes in captivity. Knowledge of types of venoms and anti-venoms is of great interest to public health. The maintenance of venomous serpents in captivity started in the early twentieth century, but still nowadays it is a challenge to manage and prevent diseases in captive fauna. Hematology is commonly used for general health assessment and illness detection. However, data on serpent blood analysis are still scarce. Alterations in hematological parameters were experimentally induced in rattlesnakes by the inoculation of BCG. Based on this, hemograms can be used as a health auxiliary diagnosis method for bacterial diseases in this species. In this study, blood samples were taken from 10 healthy specimens of rattlesnakes (Crotalus durissus) born and bred in captivity in the Herpetological Division of Vital Brazil Institute. Animals were divided into two groups (group 1 and 2) with similar live weight and sex proportion, and were then inoculated subcutaneously with BCG (Bacillus Calmette-Guérin). Blood samples were taken before and after inoculation at three experimental times (days 3, 5 and 7 for group 1 and days 11, 17 and 21 for group 2). Hematological analysis was performed through semi-direct technique, blood samples were diluted in Natt and Herrick solution and smears were stained by Giemsa. Serpents from group 1 developed discrete anemia due to the inflammatory syndrome, and showed significant decrease of MCH and MCHC. Granulocytes were characterized by the presence of rough granules. The azurophils varied in shape and size and showed large amount of cytoplasmic vacuoles. The thrombocytopenia observed in group 2 suggests that these cells participate in the inflammatory process. A single individual from group 1 showed granulocytosis and a few animals showed a discrete azurophilia. In general, BCG inoculation unleashes hematological inflammatory responses characterized by the presence of thrombocytes, azurophils and granulocytes cells

DataSheet_1_IgM antibody responses against Plasmodium antigens in neotropical primates in the Brazilian Atlantic Forest.docx

IntroductionZoonotic transmission is a challenge for the control and elimination of malaria. It has been recorded in the Atlantic Forest, outside the Amazon which is the endemic region in Brazil. However, only very few studies have assessed the antibody response, especially of IgM antibodies, in Neotropical primates (NP). Therefore, in order to contribute to a better understanding of the immune response in different hosts and facilitate the identification of potential reservoirs, in this study, naturally acquired IgM antibody responses against Plasmodium antigens were evaluated, for the first time, in NP from the Atlantic Forest.MethodsThe study was carried out using 154 NP samples from three different areas of the Atlantic Forest. IgM antibodies against peptides of the circumsporozoite protein (CSP) from different Plasmodium species and different erythrocytic stage antigens were detected by ELISA.ResultsFifty-nine percent of NP had IgM antibodies against at least one CSP peptide and 87% against at least one Plasmodium vivax erythrocytic stage antigen. Levels of antibodies against PvAMA-1 were the highest compared to the other antigens. All families of NP showed IgM antibodies against CSP peptides, and, most strikingly, against erythrocytic stage antigens. Generalized linear models demonstrated that IgM positivity against PvCSP and PvAMA-1 was associated with PCR-detectable blood-stage malaria infection and the host being free-living. Interestingly, animals with IgM against both PvCSP and PvAMA-1 were 4.7 times more likely to be PCR positive than animals that did not have IgM for these two antigens simultaneously.DiscussionIgM antibodies against different Plasmodium spp. antigens are present in NP from the Atlantic Forest. High seroprevalence and antibody levels against blood-stage antigens were observed, which had a significant association with molecular evidence of infection. IgM antibodies against CSP and AMA-1 may be used as a potential marker for the identification of NP infected with Plasmodium, which are reservoirs of malaria in the Brazilian Atlantic Forest.</p