Suckling mice is used in the isolation of?

Arbovirus REF: Jawetz's, Melnick, & Adelberg's Medical Microbiology, 24th edition cchapter 47. Principles of Diagnostic Medical MicrobiologyRecovery of Arbovirus and detection:Virus isolation attempts require appropriate biosafety precautions to prevent laboratory infections. Virus occurs in the blood only early in the infection, usually before the onset of symptoms. Virus can also be found in cerebrospinal fluid and tissue specimens, depending on the agent. Alpha viruses and flaviviruses are usually able to grow in common cell lines, such as Vero, BHK, HeLa, and MRC-5. Mosquito cell lines are useful. Intra cerebral inoculation of suckling mice or hamsters may also be used for virus isolation.