Propagation and titration of Alkhumra hemorrhagic fever virus in the brains of newborn Wistar rats.
Alkhumra hemorrhagic fever virus (AHFV) is a novel flavivirus identified first in Saudi Arabia. In this study, successful propagation of AHFV in the brains of newborn Wistar rats is described and the median rat lethal dose (RLD50) is determined. AHFV-RNA-positive human sera diluted 1:10 were injected intracerebrally into 16, ≤24h old rats. Post-inoculation, the rats were observed daily for 30 days. Brains of moribund rats were tested for AHFV-RNA using RT-PCR and cultured in LLC-MK2 cells. The titer of the isolated virus was determined and expressed in median tissue culture infectious dose (TCID50). To determine the RLD50, AHFV brain suspension was 10-fold diluted serially and each dilution was inoculated in the cerebral hemispheres of 10 rats for a total of 90 rats. Three days post-inoculation, the rats developed tremor, irritability, convulsion, opisthotonus, and spastic paresis starting in the hind limbs and ascending to involve the whole body. All infected rats died within 3-7 days with histopathologically confirmed meningoencephalitis. AHFV-RNA was detected in the brains of all infected rats and the virus titer was 10(9.4) RLD50/ml. The virus titer in LLC-MK2 was 10(8.2) TCID50/ml. In conclusion, AHFV was propagated successfully to high titers in the brains of newborn Wistar rats.
Department of Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia. Electronic address: tmadani@kau.edu.sa.
Tariq A
TA
Madani
Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
Moujahed
M
Kao
Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; The Scientific Chair of Sheikh Mohammad Hussein Alamoudi for Viral Hemorrhagic Fever, King Abdulaziz University, Jeddah, Saudi Arabia.
El-Tayeb M E
el-TM
Abuelzein
Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia.
Esam I
EI
Azhar
Department of Family and Community Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Hussein M S
HM
Al-Bar
Laboratory Animals Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
Huda
H
Abu-Araki
Department of Pathology, Faculty of Medicine, King Abdul Aziz University, Jeddah, Saudi Arabia.
Rana Y
RY
Bokhary
Galveston National Laboratory, Departments of Pathology and Microbiology and Immunology, University of Texas Branch, Galveston, TX, USA.
Thomas G
TG
Ksiazek
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000821:virology*; D004669:Encephalitis Viruses, Tick-Borne / Q000254:growth & development* / Q000302:isolation & purification* / Q000472:pathogenicity; D004671:Encephalitis, Arbovirus / Q000473:pathology / Q000821:virology; D005260:Female; D006801:Humans; D007928:Lethal Dose 50; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load; D014776:Virus Cultivation / Q000379:methods
Alkhumra hemorrhagic fever virus; Median rat lethal dose; Propagation; Wistar rats