Experimental yellow fever virus infection in the squirrel monkey (Saimiri spp.) I: gross anatomical and histopathological findings in organs at necropsy.

BACKGROUND: Non-human primates contribute to the spread of the yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas. OBJECTIVE: To describe the severe histopathological aspects of YFV infection, 10 squirrel monkeys were infected with YFV and blood, brain, liver, kidney, spleen, heart, lung, lymph node and stomach were collected at 1-7, 10, 20 and 30 days post-infection (dpi). METHODS: Histopathological analysis and detection of the genome and viral antigens and neutralising antibodies were performed by RT-PCR, immunohistochemistry and neutralisation test, respectively. FINDINGS: Only one animal died from the experimental infection. The genome and viral antigens were detected in all investigated organs (1-30 dpi) and the neutralising antibodies from seven to 30 dpi. The brain contained perivascular haemorrhage (6 dpi); in the liver, midzonal haemorrhage and lytic necrosis (6 dpi) were observed. The kidney had bleeding in the Bowman's capsule and tubular necrosis (6 dpi). Pyknotic lymphocytes were observed in the spleen (1-20 dpi), the lung had haemorrhage (2-6 dpi), in the endocardium it contained nuclear pyknosis and necrosis (2-3 dpi) and the stomach contained blood in the lumen (6 dpi). MAIN FINDINGS: Squirrel monkeys reliably reproduced the responses observed in human cases of yellow fever and, therefore, constitute an excellent experimental model for studies on the pathophysiology of the disease.

Experimental yellow fever virus infection in the squirrel monkey (Saimiri spp. ) I: gross anatomical and histopathological findings in organs at necropsy

BACKGROUND Non-human primates contribute to the spread of the yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas. OBJECTIVE To describe the severe histopathological aspects of YFV infection, 10 squirrel monkeys were infected with YFV and blood, brain, liver, kidney, spleen, heart, lung, lymph node and stomach were collected at 1-7, 10, 20 and 30 days post-infection (dpi). METHODS Histopathological analysis and detection of the genome and viral antigens and neutralising antibodies were performed by RT-PCR, immunohistochemistry and neutralisation test, respectively. FINDINGS Only one animal died from the experimental infection. The genome and viral antigens were detected in all investigated organs (1-30 dpi) and the neutralising antibodies from seven to 30 dpi. The brain contained perivascular haemorrhage (6 dpi); in the liver, midzonal haemorrhage and lytic necrosis (6 dpi) were observed. The kidney had bleeding in the Bowman's capsule and tubular necrosis (6 dpi). Pyknotic lymphocytes were observed in the spleen (1-20 dpi), the lung had haemorrhage (2-6 dpi), in the endocardium it contained nuclear pyknosis and necrosis (2-3 dpi) and the stomach contained blood in the lumen (6 dpi). MAIN FINDINGS Squirrel monkeys reliably reproduced the responses observed in human cases of yellow fever and, therefore, constitute an excellent experimental model for studies on the pathophysiology of the disease.

Determinação qualitativa da microbiota bacteriana prepucial e vaginal em macacos-da-noite (Aotus azarai infulatus) criados em cativeiro

O potencial patogênico de diferentes micro-organismos, os relatos de resistência microbiana e a escassez de informações sobre a microbiota do trato genital de primatas não humanos são fatores que justificam a realização deste estudo. O objetivo do estudo foi caracterizar a microbiota bacteriana aeróbica vaginal e prepucial dos macacos-da-noite (Aotus azarai infulatus) criados em cativeiro, avaliando suas frequências entre os sexos e a organização social (acasalados ou não), além de avaliar a sensibilidade antibacteriana. As amostras foram colhidas, de 30 animais adultos e saudáveis, pertencentes ao plantel do Centro Nacional de Primatas, Ananindeua, Pará, através de swabs. Foram semeadas e incubadas em aerobiose em ágar sangue, ágar MacConkey e ágar Chapman, para identificação bacteriana e realização dos testes de sensibilidade através do sistema automatizado VITEK® 2 Compact. Os resultados foram analisados através de estimadores da riqueza e diversidade de espécies, nas comparações foi utilizado o teste qui-quadrado (?2) com (p < 0,05). Entre as cepas gram positivas isoladas a espécie Staphylococcus intermedius foi a de maior frequência entre fêmeas e machos (48,05% e 30,30%, respectivamente). Entre as cepas gram negativas Proteus mirabilis obteve maior frequência em fêmeas (27,10%) e em machos (31,34%). As mesmas espécies também foram as mais isoladas em animais não acasalados (S. intermedius: 41,33% e P. mirabilis: 29,17%) e acasalados (S. intermedius: 38,23% e P. mirabilis: 27,85%). Para as cepas gram positivas o perfil de sensibilidade antimicrobiana in vitro foi o mesmo para ambos os sexos, apresentando 100% de resistência a benzilpenicilina e 100% de sensibilidade a gentamicina, a ciprofloxacina e a norfloxacina. Para as cepas gram negativas, as fêmeas mostraram-se 100% sensíveis somente a levofloxacina e os machos a cinco antibióticos (cefepima, meropenem, amicacina, ciprofloxacina e levofloxacina), ambos os sexos foram menos susceptíveis a nitrofurantoína (fêmeas: 33,70% e machos: 25,40%). A análise dos dados demonstrou que há similaridade entre a composição bacteriana aeróbica da mucosa prepucial e vaginal de A. a. infulatus, que os números de isolamentos e de espécies bacterianas não variam em relação ao sexo e a organização social e que o perfil de sensibilidade antimicrobiana foi semelhante em ambos os sexos para cepas gram positivas e diferente para cepas gram negativas

The pathogenic potential about different micro-organisms, the reports os microbial resistance from the genital treat of not human primates and lack of information are factors that justify the reason for this study. The purpose for this study was to characterize the vaginal and prepuce aerobic microbiota from Nighty Monkeys (Aotus azarai infulatus) raised in captivity, valuating the frequency between sex and social organization (mated or not), besides to evaluate the antibacterial sensibility. The samples were collected from 30 adult and healthy individuals,that are raised on the National Center of Primates, in the municipality of Ananindeua on the State of Pará, Brazil using swabs to do it so. They were sown and incubated in aerobics with blood agar, MacConkey agar and Chapman agar, to bacterial identification and the sensibility tests were done by the automatic system VITEK® 2 Compact. The results were checked using the estimators of richness and diversity of species, on the comparisons were used the qui-squared (Χ2) with (p < 0,05). Between the isolated gram positive strains the Staphylococcus intermedius had the major frequency among females and males (48,05% e 30,30%, respectively). Between the gram negative strains the Proteus mirabilis had major frequency on females (27,10%) and males (31,34%). The same species were the most found in not mated animals (S. intermedius: 41,33% e P. mirabilis: 29,17%) and mated (S. intermedius: 38,23% e P. mirabilis: 27,85%). To the gram positive strains the standard antimicrobial sensibility in vitro were the same for both genders, showing 100% of resistance to benzilpenicilina and 100% de of sensigility against gentamicina, ciprofloxacina and norfloxacina. To the gram negative strains, he females showed 100% of sensibility against levofloxacina and the males against five antibiotics (cefepima, meropenem, amicacina, ciprofloxacina and levofloxacina), both genders were less sensitive to nitrofurantoína (females: 33,70% and males: 25,40%). The data analysis showed that are similiarity between the aerobic bacterial composition of the prepuce and vaginal mucosa from A. a. infulatus, and the numbers of isolations and bacterial species don’t vary related to gender and social organization and the standard antimicrobial sensibility were the same among genders to gram positive and different for gram negative strains.