Sensitive assays for isolation and detection of simian foamy retroviruses

Simian foamy viruses (SFVs) are highly prevalent in a variety of nonhuman p rimate species ranging from prosimians to apes, SFVs possess a broad host r ange, and human infections can occur by cross-species transfer (W, Heneine et al., Nat, Med, 4:403-407, 1998). Retrovirus screening of potential sourc es of infection, such as laboratory research animals and simian-derived bio logical products, could minimize human exposure to SFVs by reducing the ris k of potential retrovirus infection in humans. We describe a variety of sen sitive assays for SFV isolation and detection which were developed with a p rototype strain of SFV serotype 2, The Mns dunni cell line (M, R, Lander an d S. K, Chattopadhyay, J. Virol, 52:695-698, 1984) was found to be highly s ensitive for SFV production on the basis of various general and specific re trovirus detection assays such as reverse transcriptase assay, transmission electron microscopy, immunofluorescence assay, and Western blotting. A hig hly sensitive PCR assay was developed on the basis of the sequences in prim ary SFV isolates obtained from pig-tailed macaques (Macaca nemestrina) and rhesus macaques (Macaca mulatta). Analysis of naturally occurring SFV infec tion in macaques indicated that analysis by a combination of assays, includ ing both highly sensitive, specific assays and less sensitive, broadly reac tive assays, is important for evaluation of retrovirus infection.