45 research outputs found
Identification of super-infected Aedes triseriatus mosquitoes collected as eggs from the field and partial characterization of the infecting La Crosse viruses
Exposure of Egyptian Rousette Bats (\u3ci\u3eRousettus aegyptiacus\u3c/i\u3e) and a Little Free-Tailed Bat (\u3ci\u3eChaerephon pumilus\u3c/i\u3e) to Alphaviruses in Uganda
The reservoir for zoonotic o’nyong-nyong virus (ONNV) has remained unknown since this virus was first recognized in Uganda in 1959. Building on existing evidence for mosquito bloodfeeding on various frugivorous bat species in Uganda, and seroprevalence for arboviruses among bats in Uganda, we sought to assess if serum samples collected from bats in Uganda demonstrated evidence of exposure to ONNV or the closely related zoonotic chikungunya virus (CHIKV). In total, 652 serum samples collected from six bat species were tested by plaque reduction neutralization test (PRNT) for neutralizing antibodies against ONNV and CHIKV. Forty out of 303 (13.2%) Egyptian rousettes from Maramagambo Forest and 1/13 (8%) little free-tailed bats from Banga Nakiwogo, Entebbe contained neutralizing antibodies against ONNV. In addition, 2/303 (0.7%) of these Egyptian rousettes contained neutralizing antibodies to CHIKV, and 8/303 (2.6%) contained neutralizing antibodies that were nonspecifically reactive to alphaviruses. These data support the interepidemic circulation of ONNV and CHIKV in Uganda, although Egyptian rousette bats are unlikely to serve as reservoirs for these viruses given the inconsistent occurrence of antibody-positive bats
Discovery and Characterization of Bukakata orbivirus (\u3ci\u3eReoviridae:Orbivirus\u3c/i\u3e), a Novel Virus from a Ugandan Bat
While serological and virological evidence documents the exposure of bats to medically important arboviruses, their role as reservoirs or amplifying hosts is less well-characterized. We describe a novel orbivirus (Reoviridae:Orbivirus) isolated from an Egyptian fruit bat (Rousettus aegyptiacus leachii) trapped in 2013 in Uganda and named Bukakata orbivirus. This is the fifth orbivirus isolated from a bat, however genetic information had previously only been available for one bat-associated orbivirus. We performed whole-genome sequencing on Bukakata orbivirus and three other bat-associated orbiviruses (Fomede, Ife, and Japanaut) to assess their phylogenetic relationship within the genus Orbivirus and develop hypotheses regarding potential arthropod vectors. Replication kinetics were assessed for Bukakata orbivirus in three different vertebrate cell lines. Lastly, qRT-PCR and nested PCR were used to determine the prevalence of Bukakata orbivirus RNA in archived samples from three populations of Egyptian fruit bats and one population of cave-associated soft ticks in Uganda. Complete coding sequences were obtained for all ten segments of Fomede, Ife, and Japanaut orbiviruses and for nine of the ten segments for Bukakata orbivirus. Phylogenetic analysis placed Bukakata and Fomede in the tick-borne orbivirus clade and Ife and Japanaut within the Culicoides/phlebotomine sandfly orbivirus clade. Further, Bukakata and Fomede appear to be serotypes of the Chobar Gorge virus species. Bukakata orbivirus replicated to high titers (106–107 PFU/mL) in Vero, BHK-21 [C-13], and R06E (Egyptian fruit bat) cells. Preliminary screening of archived bat and tick samples do not support Bukakata orbivirus presence in these collections, however additional testing is warranted given the phylogenetic associations observed. This study provided complete coding sequence for several bat-associated orbiviruses and in vitro characterization of a bat-associated orbivirus. Our results indicate that bats may play an important role in the epidemiology of viruses in the genus Orbivirus and further investigation is warranted into vector-host associations and ongoing surveillance efforts
Discovery and Characterization of Bukakata orbivirus (\u3ci\u3eReoviridae:Orbivirus\u3c/i\u3e), a Novel Virus from a Ugandan Bat
While serological and virological evidence documents the exposure of bats to medically important arboviruses, their role as reservoirs or amplifying hosts is less well-characterized. We describe a novel orbivirus (Reoviridae:Orbivirus) isolated from an Egyptian fruit bat (Rousettus aegyptiacus leachii) trapped in 2013 in Uganda and named Bukakata orbivirus. This is the fifth orbivirus isolated from a bat, however genetic information had previously only been available for one bat-associated orbivirus. We performed whole-genome sequencing on Bukakata orbivirus and three other bat-associated orbiviruses (Fomede, Ife, and Japanaut) to assess their phylogenetic relationship within the genus Orbivirus and develop hypotheses regarding potential arthropod vectors. Replication kinetics were assessed for Bukakata orbivirus in three different vertebrate cell lines. Lastly, qRT-PCR and nested PCR were used to determine the prevalence of Bukakata orbivirus RNA in archived samples from three populations of Egyptian fruit bats and one population of cave-associated soft ticks in Uganda. Complete coding sequences were obtained for all ten segments of Fomede, Ife, and Japanaut orbiviruses and for nine of the ten segments for Bukakata orbivirus. Phylogenetic analysis placed Bukakata and Fomede in the tick-borne orbivirus clade and Ife and Japanaut within the Culicoides/phlebotomine sandfly orbivirus clade. Further, Bukakata and Fomede appear to be serotypes of the Chobar Gorge virus species. Bukakata orbivirus replicated to high titers (106–107 PFU/mL) in Vero, BHK-21 [C-13], and R06E (Egyptian fruit bat) cells. Preliminary screening of archived bat and tick samples do not support Bukakata orbivirus presence in these collections, however additional testing is warranted given the phylogenetic associations observed. This study provided complete coding sequence for several bat-associated orbiviruses and in vitro characterization of a bat-associated orbivirus. Our results indicate that bats may play an important role in the epidemiology of viruses in the genus Orbivirus and further investigation is warranted into vector-host associations and ongoing surveillance efforts
Isolation and molecular characterization of Fikirini rhabdovirus, a novel virus from a Kenyan bat
Zoonotic and vector-borne pathogens have comprised a significant component of emerging human
infections in recent decades, and bats are increasingly recognized as reservoirs for many of these disease
agents. To identify novel pathogens associated with bats, we screened tissues of bats collected in Kenya.
Virus isolates were identified by next generation sequencing of viral nucleic acid preparations from the
infected cell culture supernatant and characterized molecularly. Here we report the identification of
Fikirini rhabdovirus, a novel rhabdovirus isolated from a bat, Hipposideros vittatus, captured along the
Kenyan coast.Technical Support Corps funds from the Global Disease Detection Program of the
Centers for Disease Control and Prevention (Atlanta, GA), and by an Interagency Agreement between the United States Agency for International Development Emerging Pandemic Threats Program and the United States Centers for Disease Control and Prevention.http://vir.sgmjournals.orghb201
Quasi-local conserved charges and spin transport in spin-1 integrable chains
We consider the integrable one-dimensional spin-1 chain defined by the Zamolodchikov-Fateev (ZF) Hamiltonian. The latter is parametrized, analogously to the XXZ spin-1/2 model, by a continuous anisotropy parameter and at the isotropic point coincides with the well-known spin-1 Babujian-Takhtajan Hamiltonian. Following a procedure recently developed for the XXZ model, we explicitly construct a continuous family of quasi-local conserved operators for the periodic spin-1 ZF chain. Our construction is valid for a dense set of commensurate values of the anisotropy parameter in the gapless regime where the isotropic point is excluded. Using the Mazur inequality, we show that, as for the XXZ model, these quasi-local charges are enough to prove that the high-temperature spin Drude weight is non-vanishing in the thermodynamic limit, thus establishing ballistic spin transport at high temperature
Eastern equine encephalitis virus in mice I: clinical course and outcome are dependent on route of exposure
Rotavirus Genome Segment 7 (NSP3) Is a Determinant of Extraintestinal Spread in the Neonatal Mouse
We used the neonatal mouse model of rotavirus infection to study extraintestinal spread following oral inoculation. Five-day-old pups were inoculated with either SA11-Cl3, SA11-Cl4, SA11-4F, RRV, or B223. By using virus detection in the liver as a proxy determination for extraintestinal spread, rotavirus strains capable of extraintestinal spread at high frequency (rhesus rotavirus [RRV]) and very low frequency (SA11-Cl4) were identified. Both strains productively infected the gastrointestinal tract. Oral inoculation of mice with RRV/ SA11-Cl4 reassortants and determination of virus titers in the gut and liver revealed that the extraintestinal spread phenotype segregated with RRV genome segment 7 to a high level of significance (P = 10(−3)). RRV segment 7 also segregated with the growth of virus in the gut (P = 10(−5)). Although infection of the gut was clearly required for tropism to the liver, there was no correlation between virus titers in the gut and detection of virus in the liver. Five days after intraperitoneal administration to bypass the gut barrier to virus spread, RRV and SA11-Cl4 both were recovered in the liver. However, only RRV was found in the liver following subcutaneous inoculation, suggesting that this peripheral site presented a similar barrier to virus spread as the gut. Sequence analysis of segment 7 from parental RRV and SA11-Cl4 and selected reassortants showed that (i) amino acid differences were distributed throughout the coding sequences and not concentrated in any particular functional motif and (ii) parental sequence was preserved in reassortants. These data support the hypothesis that NSP3, coded for by genome segment 7, plays a significant role in viral growth in the gut and spread to peripheral sites. The mechanism of NSP3-mediated tropism is under investigation
A Lymphatic Mechanism of Rotavirus Extraintestinal Spread in the Neonatal Mouse
We used the neonatal mouse model of rotavirus infection and virus strains SA11-clone 4 (SA11-Cl4) and Rhesus rotavirus (RRV) to examine the mechanism of the extraintestinal spread of viruses following oral inoculation. The spread-competent viruses, RRV and reassortant R7, demonstrated a temporal progression from the intestine, to the terminal ileum, to the mesenteric lymph nodes (MLN), and to the peripheral tissues. SA11-Cl4 was not found outside the intestine. Reassortant virus S7, which was unable to reach the liver in previous studies (E. C. Mossel and R. F. Ramig, J. Virol. 76:6502-6509, 2002), was recovered from 60% of the MLN, suggesting that there are multiple determinants for the spread of virus from the intestine to the MLN. Phenotypic segregation analysis identified RRV genome segment 6 (VP6) as a secondary determinant of the spread of virus to the MLN (P = 0.02) in reassortant viruses containing segment 7 from the spread-incompetent parent. These data suggest that in the orally infected neonatal mouse, the extraintestinal spread of rotavirus occurs via a lymphatic pathway, and the spread phenotype is primarily determined by NSP3 and can be modified by VP6