Virus zika is an arbovirus transmitted by Aedes mosquitoes, occurring described together with the... more Virus zika is an arbovirus transmitted by Aedes mosquitoes, occurring described together with the increase in microcephaly in newborns. In view of the severity associated with cases of microcephaly and other neurological disorders, the World Health Organization came to characterize it as a Public Health Emergency of National Importance. The objective of this work was to determine the expression profile of genes that encode key proteins related to microRNA and apoptosis pathways in neural cells of rodents of the Muridae family infected by this virus. The infected neural cells were Neuro-2a, and the methods employed were quantitative reverse transcription polymerase chain reaction and bioluminescence. Viral production and caspase-3/7 activation were higher at 96 hours after infection, as well as the expression of genes encoding Ago1, DGCR8, RIG-I and FAS-L.
Background-Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced... more Background-Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced an explosive epidemic. However, recent studies indicate that the introduction of ZIKV occurred in late 2013. Cases of microcephaly and deaths associated with ZIKV infection were identified in Brazil in November, 2015. Objectives-To determine the etiology of three fatal adult cases. Study design-Here we report three fatal adult cases of ZIKV disease. ZIKV infection in these patients was confirmed by cells culture and/or real-time reverse transcriptase polymerase chain *
Because of its ecological characteristics, the Caxiuanã National Forest (FLONA) is a potential ar... more Because of its ecological characteristics, the Caxiuanã National Forest (FLONA) is a potential area of arbovirus circulation. The present study aimed to investigate the occurrence of arbovirus transmission cycles at FLONA de Caxiuanã. Five field trips were performed to capture mosquitoes and sylvatic vertebrates. For these vertebrates, we attempted viral isolation by cell monolayer inoculation from blood, and hemagglutination inhibition and further seroneutralization assays from sera. For mosquitoes, we performed tests of viral genome detection. A total of 338 vertebrates were captured, and the greatest representative was birds (251/74.26%). A total of 16,725 mosquitoes were captured, distributed among 56 species. There were no viruses isolated by newborn mouse inoculation. Among birds, antibodies against Ilheus virus were the most prevalent. Catu virus, Caraparu virus, and Mucambo virus were the most prevalent among mammals and reptiles. Fragments of Mucambo virus, Ilheus virus, Bu...
The American Journal of Tropical Medicine and Hygiene, 2006
We studied the molecular epidemiology of dengue virus type 3 (DENV-3) in Brazil and Paraguay by a... more We studied the molecular epidemiology of dengue virus type 3 (DENV-3) in Brazil and Paraguay by analyzing the 5Ј and 3Ј untranslated regions (5Ј and 3ЈUTRs) and the E protein gene of viruses isolated between 2002 and 2004. Both 5Ј and 3ЈUTRs were highly conserved. However, the 3ЈUTR of two isolates from Brazil contained eight nucleotide deletions compared with the remaining 26 viruses. Phylogenetic analyses suggested that DENV-3 was introduced into Brazil from the Caribbean Islands at least twice and into Paraguay from Brazil at least three times.
This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arbo... more This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arboviruses were detected in the biological samples of approximately one-third of patients with encephalitis, myelitis, encephalomyelitis or Guillain-Barré syndrome, in a surveillance programme in Piauí state, Brazil, between 2015-2016. Fever and myalgia had been associated with these cases. Since in non-tropical countries most infections or parainfectious diseases associated with the nervous system are attributed to herpesviruses, enteroviruses, and Campylobacter jejuni, the present findings indicate that in tropical countries, arboviruses may now play a more important role and reinforce the need for their surveillance and systematic investigation in the tropics.
Revista da Sociedade Brasileira de Medicina Tropical
We report a case of encephalitis associated with Zika virus infection and reactivation of varicel... more We report a case of encephalitis associated with Zika virus infection and reactivation of varicella-zoster virus in the central nervous system of a Brazilian child. This case raises the possibility that reactivation of the latent varicella-zoster virus may be a mechanism of neurological impairment induced by acquired Zika virus infection.
Chikungunya (CHIKV) and Zika (ZIKV) viruses are two arboviruses which have recently broken their ... more Chikungunya (CHIKV) and Zika (ZIKV) viruses are two arboviruses which have recently broken their sylvatic isolation and gone into a rampant spreading among humans in some urban areas of the world, specially in Latin America. Given the huge burden that Chikungunya and Zika fevers impose to public health in the affected countries and the lack of effective interventions against them, the aim of this work was to evaluate the antiviral potential of bovine lactoferrin (bLf) – an iron-binding glycoprotein with broad-spectrum antimicrobial properties – in both CHIKV and ZIKV infections. The general antiviral activity of bLf was assessed by plaque assays, and the inhibitory effects of the protein on specific stages of virus infecion was evaluated by immunofluorescence and nucleic acid quantification assays. Our data show that bLf exerts a dose-dependent strong inhibitory effect on the infection of Vero cells by the aforementioned arboviruses, reducing their infection efficiency in up to near...
The American Journal of Tropical Medicine and Hygiene, 2015
A Brazilian ranch worker with encephalitis and flaccid paralysis was evaluated in the regional Ac... more A Brazilian ranch worker with encephalitis and flaccid paralysis was evaluated in the regional Acute Encephalitis Syndromic Surveillance Program. This was the first Brazilian patient who met the Centers for Disease Control and Prevention (CDC) confirmation criteria for West Nile virus disease. Owing to the overlapping of neurological manifestations attributable to several viral infections of the central nervous system, this report exemplifies the importance of human acute encephalitis surveillance. The syndromic approach to human encephalitis cases may enable early detection of the introduction of unusual virus or endemic occurrence of potentially alarming diseases within a region.
The immunity of horses (n = 1401) against Saint Louis encephalitis virus (SLEV) was investigated ... more The immunity of horses (n = 1401) against Saint Louis encephalitis virus (SLEV) was investigated in the Brazilian Amazon region (Bragança/Pará, Salvaterra/Pará, Macapá/Amapá and Rio Branco/Acre) and Maracaju, State of Mato Grosso do Sul, by the hemagglutination inhibition (HI) and plaque reduction neutralization (PRNT) tests. HI and neutralizing antibodies specific (monotypic reactivity, MR) for SLEV and other flaviviruses included in the tests were detected, as was cross-reactivity (CR) against flaviviruses. In the HI test, MR was observed in 248 (17.7%) serum samples, 137 of which were (55.2%) against SLEV; CR was detected in 380 (27.1%). The frequency of MR against SLEV was significantly higher in Macapá and CR was significantly higher in Salvaterra. In the PRNT, neutralization of SLEV was observed in 713 (50.9%) samples, and the prevalence of neutralizing antibodies was significantly higher in Macapá than in Salvaterra (p = 0.0083). This study adds new data regarding the immunity of horses against SLEV in Brazil, and it confirms the wide distribution of SLEV and the diversity of flaviviruses in the country, as well as the apparent absence of disease in SLEV-infected horses.
Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infec... more Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD 50 /0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.
International Journal of Experimental Pathology, 2007
SummaryMinaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goi... more SummaryMinaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goiás State, Brazil, in 1996. In attempting characterization of virus serological (hemagluttination inhibition, HI; indirect immunofluorescence assay, IFA), physicochemical [test for deoxycholate acid (DCA) sensitivity; polyacrylamide gel electrophoresis (PAGE)] tests and ultrastructural studies were made. Virus was also assayed in suckling mice after intracerebral inoculation of 0.02 ml and in VERO and C6/36 cells with 0.1 ml of viral suspension containing 105 LD50/ml. Inoculated and control systems were observed daily. Every 24 h, one control and two inoculated animals were killed for tissue testing, including histopathological changes by haematoxylin and eosin (HE)‐stained sections, which were semi‐quantified. Research into viral antigen in the tissues of mice [central nervous system (CNS), liver, heart, lungs, spleen and kidneys] was carried out by the immunohistochemical technique usin...
The American Journal of Tropical Medicine and Hygiene, 2005
This paper reports the results of serologic, structural, biochemical, and genetic studies indicat... more This paper reports the results of serologic, structural, biochemical, and genetic studies indicating that Araguari virus, a previously unassigned viral agent, is a member of the family Orthomyxoviridae and genus Thogotovirus. Araguari virus has six RNA fragments; biologically, it shares several properties with other viruses in the family Orthomyxoviridae. Nucleotide sequencing of the RNA segments 4 (glycoprotein) and 5 (nucleoprotein) of Araguari virus aligned with the orthomyxoviruses, showing the closest relationship with Thogoto virus (sequence similarity ס 61.9% and 69.1%, respectively, for glycoprotein and nucleoprotein), but also sharing a more distant similarity with Dhori and Influenza C viruses, especially for the glycoprotein gene. Based on these results, we propose that Araguari virus should be assigned as a new member of the family Orthomyxoviridae and genus Thogotovirus.
We report here the first complete genome sequence of a Changuinola virus (CGLV) serotype Irituia ... more We report here the first complete genome sequence of a Changuinola virus (CGLV) serotype Irituia virus (BE AN 28873) isolated from a wild rodent (Oryzomys goeldi) in the municipality of Ipixuna, State of Pará, northern Brazil. All genome segments showed similarity with those belonging to members of the genus Orbivirus, family Reoviridae.
Virus zika is an arbovirus transmitted by Aedes mosquitoes, occurring described together with the... more Virus zika is an arbovirus transmitted by Aedes mosquitoes, occurring described together with the increase in microcephaly in newborns. In view of the severity associated with cases of microcephaly and other neurological disorders, the World Health Organization came to characterize it as a Public Health Emergency of National Importance. The objective of this work was to determine the expression profile of genes that encode key proteins related to microRNA and apoptosis pathways in neural cells of rodents of the Muridae family infected by this virus. The infected neural cells were Neuro-2a, and the methods employed were quantitative reverse transcription polymerase chain reaction and bioluminescence. Viral production and caspase-3/7 activation were higher at 96 hours after infection, as well as the expression of genes encoding Ago1, DGCR8, RIG-I and FAS-L.
Background-Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced... more Background-Zika virus (ZIKV) was first detected in Brazil in May 2015 and the country experienced an explosive epidemic. However, recent studies indicate that the introduction of ZIKV occurred in late 2013. Cases of microcephaly and deaths associated with ZIKV infection were identified in Brazil in November, 2015. Objectives-To determine the etiology of three fatal adult cases. Study design-Here we report three fatal adult cases of ZIKV disease. ZIKV infection in these patients was confirmed by cells culture and/or real-time reverse transcriptase polymerase chain *
Because of its ecological characteristics, the Caxiuanã National Forest (FLONA) is a potential ar... more Because of its ecological characteristics, the Caxiuanã National Forest (FLONA) is a potential area of arbovirus circulation. The present study aimed to investigate the occurrence of arbovirus transmission cycles at FLONA de Caxiuanã. Five field trips were performed to capture mosquitoes and sylvatic vertebrates. For these vertebrates, we attempted viral isolation by cell monolayer inoculation from blood, and hemagglutination inhibition and further seroneutralization assays from sera. For mosquitoes, we performed tests of viral genome detection. A total of 338 vertebrates were captured, and the greatest representative was birds (251/74.26%). A total of 16,725 mosquitoes were captured, distributed among 56 species. There were no viruses isolated by newborn mouse inoculation. Among birds, antibodies against Ilheus virus were the most prevalent. Catu virus, Caraparu virus, and Mucambo virus were the most prevalent among mammals and reptiles. Fragments of Mucambo virus, Ilheus virus, Bu...
The American Journal of Tropical Medicine and Hygiene, 2006
We studied the molecular epidemiology of dengue virus type 3 (DENV-3) in Brazil and Paraguay by a... more We studied the molecular epidemiology of dengue virus type 3 (DENV-3) in Brazil and Paraguay by analyzing the 5Ј and 3Ј untranslated regions (5Ј and 3ЈUTRs) and the E protein gene of viruses isolated between 2002 and 2004. Both 5Ј and 3ЈUTRs were highly conserved. However, the 3ЈUTR of two isolates from Brazil contained eight nucleotide deletions compared with the remaining 26 viruses. Phylogenetic analyses suggested that DENV-3 was introduced into Brazil from the Caribbean Islands at least twice and into Paraguay from Brazil at least three times.
This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arbo... more This study showed that laboratory markers of recent infection by dengue, Zika or chikungunya arboviruses were detected in the biological samples of approximately one-third of patients with encephalitis, myelitis, encephalomyelitis or Guillain-Barré syndrome, in a surveillance programme in Piauí state, Brazil, between 2015-2016. Fever and myalgia had been associated with these cases. Since in non-tropical countries most infections or parainfectious diseases associated with the nervous system are attributed to herpesviruses, enteroviruses, and Campylobacter jejuni, the present findings indicate that in tropical countries, arboviruses may now play a more important role and reinforce the need for their surveillance and systematic investigation in the tropics.
Revista da Sociedade Brasileira de Medicina Tropical
We report a case of encephalitis associated with Zika virus infection and reactivation of varicel... more We report a case of encephalitis associated with Zika virus infection and reactivation of varicella-zoster virus in the central nervous system of a Brazilian child. This case raises the possibility that reactivation of the latent varicella-zoster virus may be a mechanism of neurological impairment induced by acquired Zika virus infection.
Chikungunya (CHIKV) and Zika (ZIKV) viruses are two arboviruses which have recently broken their ... more Chikungunya (CHIKV) and Zika (ZIKV) viruses are two arboviruses which have recently broken their sylvatic isolation and gone into a rampant spreading among humans in some urban areas of the world, specially in Latin America. Given the huge burden that Chikungunya and Zika fevers impose to public health in the affected countries and the lack of effective interventions against them, the aim of this work was to evaluate the antiviral potential of bovine lactoferrin (bLf) – an iron-binding glycoprotein with broad-spectrum antimicrobial properties – in both CHIKV and ZIKV infections. The general antiviral activity of bLf was assessed by plaque assays, and the inhibitory effects of the protein on specific stages of virus infecion was evaluated by immunofluorescence and nucleic acid quantification assays. Our data show that bLf exerts a dose-dependent strong inhibitory effect on the infection of Vero cells by the aforementioned arboviruses, reducing their infection efficiency in up to near...
The American Journal of Tropical Medicine and Hygiene, 2015
A Brazilian ranch worker with encephalitis and flaccid paralysis was evaluated in the regional Ac... more A Brazilian ranch worker with encephalitis and flaccid paralysis was evaluated in the regional Acute Encephalitis Syndromic Surveillance Program. This was the first Brazilian patient who met the Centers for Disease Control and Prevention (CDC) confirmation criteria for West Nile virus disease. Owing to the overlapping of neurological manifestations attributable to several viral infections of the central nervous system, this report exemplifies the importance of human acute encephalitis surveillance. The syndromic approach to human encephalitis cases may enable early detection of the introduction of unusual virus or endemic occurrence of potentially alarming diseases within a region.
The immunity of horses (n = 1401) against Saint Louis encephalitis virus (SLEV) was investigated ... more The immunity of horses (n = 1401) against Saint Louis encephalitis virus (SLEV) was investigated in the Brazilian Amazon region (Bragança/Pará, Salvaterra/Pará, Macapá/Amapá and Rio Branco/Acre) and Maracaju, State of Mato Grosso do Sul, by the hemagglutination inhibition (HI) and plaque reduction neutralization (PRNT) tests. HI and neutralizing antibodies specific (monotypic reactivity, MR) for SLEV and other flaviviruses included in the tests were detected, as was cross-reactivity (CR) against flaviviruses. In the HI test, MR was observed in 248 (17.7%) serum samples, 137 of which were (55.2%) against SLEV; CR was detected in 380 (27.1%). The frequency of MR against SLEV was significantly higher in Macapá and CR was significantly higher in Salvaterra. In the PRNT, neutralization of SLEV was observed in 713 (50.9%) samples, and the prevalence of neutralizing antibodies was significantly higher in Macapá than in Salvaterra (p = 0.0083). This study adds new data regarding the immunity of horses against SLEV in Brazil, and it confirms the wide distribution of SLEV and the diversity of flaviviruses in the country, as well as the apparent absence of disease in SLEV-infected horses.
Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infec... more Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD 50 /0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.
International Journal of Experimental Pathology, 2007
SummaryMinaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goi... more SummaryMinaçu virus was isolated from Ochlerotatus scapularis (Diptera: Culicidae) in Minaçu, Goiás State, Brazil, in 1996. In attempting characterization of virus serological (hemagluttination inhibition, HI; indirect immunofluorescence assay, IFA), physicochemical [test for deoxycholate acid (DCA) sensitivity; polyacrylamide gel electrophoresis (PAGE)] tests and ultrastructural studies were made. Virus was also assayed in suckling mice after intracerebral inoculation of 0.02 ml and in VERO and C6/36 cells with 0.1 ml of viral suspension containing 105 LD50/ml. Inoculated and control systems were observed daily. Every 24 h, one control and two inoculated animals were killed for tissue testing, including histopathological changes by haematoxylin and eosin (HE)‐stained sections, which were semi‐quantified. Research into viral antigen in the tissues of mice [central nervous system (CNS), liver, heart, lungs, spleen and kidneys] was carried out by the immunohistochemical technique usin...
The American Journal of Tropical Medicine and Hygiene, 2005
This paper reports the results of serologic, structural, biochemical, and genetic studies indicat... more This paper reports the results of serologic, structural, biochemical, and genetic studies indicating that Araguari virus, a previously unassigned viral agent, is a member of the family Orthomyxoviridae and genus Thogotovirus. Araguari virus has six RNA fragments; biologically, it shares several properties with other viruses in the family Orthomyxoviridae. Nucleotide sequencing of the RNA segments 4 (glycoprotein) and 5 (nucleoprotein) of Araguari virus aligned with the orthomyxoviruses, showing the closest relationship with Thogoto virus (sequence similarity ס 61.9% and 69.1%, respectively, for glycoprotein and nucleoprotein), but also sharing a more distant similarity with Dhori and Influenza C viruses, especially for the glycoprotein gene. Based on these results, we propose that Araguari virus should be assigned as a new member of the family Orthomyxoviridae and genus Thogotovirus.
We report here the first complete genome sequence of a Changuinola virus (CGLV) serotype Irituia ... more We report here the first complete genome sequence of a Changuinola virus (CGLV) serotype Irituia virus (BE AN 28873) isolated from a wild rodent (Oryzomys goeldi) in the municipality of Ipixuna, State of Pará, northern Brazil. All genome segments showed similarity with those belonging to members of the genus Orbivirus, family Reoviridae.
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