OBJECTIVETo evaluate the susceptibility of Aedes albopictus and Culex pipiens quinquefasciatus to oral infection with bat Japanese encephalitis virus isolates (GD1 and HN2 strains).

METHODSAedes albopictus and Culex pipiens quinquefasciatus were infected orally by GD1 and HN2 strains of bat Japanese encephalitis virus. TaqMan real-time PCR was used to detect the virus and monitor the changes in the viral loads in Aedes albopictus and Culex pipiens quinquefasciatus at a 2-day interval, starting from 4 days till 20 days after the infection.

RESULTSThe infected Aedes albopictus and Culex pipiens quinquefasciatus were found positive for the Japanese encephalitis virus from day 4 to day 20. Both Aedes albopictus and Culex pipiens quinquefasciatus were susceptible to infection by GD1 and HN2 strains, but the latter showed a greater susceptibility. The HN2 strain virus appeared to have a greater virulence than the GD1 strain.

CONCLUSIONAedes albopictus and Culex pipiens quinquefasciatus can carry GD1 and HN2 strains of bat Japanese encephalitis virus isolates.

Aedes ; virology ; Animals ; Chiroptera ; virology ; Culex ; virology ; Disease Susceptibility ; Encephalitis Virus, Japanese ; isolation & purification

Angiotensin-Converting Enzyme 2/metabolism* ; COVID-19/virology* ; Disease Susceptibility ; Humans ; SARS-CoV-2/pathogenicity* ; Species Specificity

To explore the infectivity characteristics and susceptibility of Sendai strain Tianjin in 129Sv, DBA/2, Kunming and BALB/c mice and determine the optimal small rodent animal model for strain Tianjin research, the Sendai strain Tianjin was propagated for 72h in 9-11 day-old chicken embryos, the allantoic fluids were then harvested and the virus titer (1:1280) was detected by hemagglutination assay. Four different kinds of mice were intranasally inoculated with 5 microl and the diluted 30 microl virus solution. The weight loss of mice was monitored for 12 consecutive days and the survival rate was observed. Kunming and BALB/c mice were sacrificed on the first day prior to infection and on the fourth and seventh days post infection of the diluted 30 microl Sendai strain Tianjin. Their left lobes of lung were fixed with 4% formalin for histopathologic examination. The maximum percentage of average weight loss of 129Sv, DBA/2 were 13.0%, 4.7% with 100% survival rate when 129Sv, DBA/2, Kunming and BALB/c were inoculated with 5 microl virus solution, while the mice were inoculated with diluted 30 microl virus solution, the maximum percentage of average weight loss reached 21.7%, 30.3%, 16.7% and 9.7% with the survival rate of 20%, 0%, 80% and 100%. Lung infections of mice Kunming on the fourth and seventh day post infection were more severe than that of BALB/c, showing a large number of inflammatory cell exudation and thickening of the submucosa. It suggested that DBA/2 was the most susceptible to the infection of strain Tianjin. The mice susceptibility ranked as DBA/2>129Sv>Kunming>BALB/c. Mice DBA/2 and 129Sv could be used as the optimal small rodent animal models in the research of pathogenicity and vaccine of Sendai strain Tianjin.
Animals ; Disease Susceptibility ; Female ; Humans ; Lung ; pathology ; virology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred DBA ; Respirovirus Infections ; physiopathology ; virology ; Sendai virus ; classification ; physiology

Integrin alphavbeta3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of alphavbeta3 integrin, a stable CHO-677 cell line expressing the murine alphavbeta3 heterodimer (designated as "CHO-677-malphavbeta3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits alphav and beta3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-malphavbeta3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-malphavbeta3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable alphavbeta3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of alphavbeta3 integrin, and as a cell model for FMDV research.
Animals ; Animals, Suckling ; CHO Cells ; Cloning, Molecular ; Cricetulus ; DNA, Complementary/genetics/metabolism ; Disease Susceptibility/virology ; Foot-and-Mouth Disease/*genetics/virology ; Foot-and-Mouth Disease Virus/*physiology ; Integrin alphaVbeta3/*genetics/metabolism ; Mice

OBJECTIVETo study the susceptibility of Aedes albopictus to dengue virus infection.

METHODSAedes albopictus from 15 collections in Guizhou province were challenged orally with dengue virus 1-4 types, respectively. The total RNA from mosquitos were extracted. The viral NS1 gene fragment was amplified with reverse transcriptase polymerase chain reaction (RT-PCR). Dengue virus in mosquitoes was isolated with C6/36 cells. Then the viral antigen was detected by indirect immunofluorescence assay (IFA). Antigen and nucleic acid of dengue virus from 15 geographic strains of Aedes albopictus orally infected with dengue viruses (DEN-1, DEN-2, DEN-3 and DEN-4) were detected by IFA, RT-PCR and the virus was isolated with C6/36 cells, respectively.

RESULTSThe rates of Aedes albopictus orally infected with DEN-1, DEN-2, DEN-3 and DEN-4 were 12/15, 12/15, 8/15 and 13/15, respectively.

CONCLUSIONSDifferent geographic strains of Aedes albopitus in Guizhou were susceptible to dengue viruses.

Aedes ; cytology ; virology ; Animals ; Antigens, Viral ; analysis ; Cell Line ; China ; DNA, Viral ; analysis ; Dengue Virus ; genetics ; isolation & purification ; Disease Susceptibility ; Ecosystem ; Reverse Transcriptase Polymerase Chain Reaction ; Viral Nonstructural Proteins ; genetics