Western blot assays using human serum. Dilutions of human serum (lanes 2–11) or a foamy virus–-positive Macaca mulatta MBG8 (lane 1) were used to probe filter strips containing equal amounts of lysates from simian foamy virus–infected cells (from M. fascicularis; i lanes) or noninfected cells (u lanes). Individual strips were developed by using TMB reagent (3,3′,5,5′-tetramethylbenzidine; Promega, Madison, WI, USA). The positions of the viral proteins Gag and Bet are indicated. Lanes 10 and 11 show the range of reactivity seen with negative serum; lane 10 shows serum with nonspecific reactivity to proteins of approximately the same size as viral proteins; lane 11 shows serum negative for both lysates.

Map of the diverse contexts, countries, and nonhuman primate (Macaca) species associated with human infection with simian foamy virus.

Phylogenetic trees of simian foamy virus (SFV) sequences derived from 3 persons. Human-derived SFV sequences (shown in boldface) were compared with those obtained from macaques of the group with which the person had been in contact and to SFV from other macaques of the same species but different geographic origin. Neighbor-joining trees A and B used gag PCR primers (1,124 bp), and C used pol PCR primers (445 bp). A) SFV gag–derived from BGH4 DNA clusters more closely (94% of bootstrap samplings) with gag sequences from 4 Macaca mulatta that ranged throughout her village (MBG4, MBG11, MBG13, and MBG14) than with gag sequences obtained from Bangladeshi performing monkeys, M. mulatta (MBG7, MBG8), of unknown origin. BGH4 gag is equidistant from gag of MBG7, MBG8, and virus obtained from SFVmulO, an M. mulatta of unknown origin housed at the Oregon National Regional Primate Center. B) SFV gag from HAD3, a worker at a Bali monkey temple, grouped with gag from several M. fascicularis (AK4, AK19, AK23) found at the same temple (100% of bootstrap samplings). UB3 is also an M. fascicularis Bali temple monkey that inhabited a temple ≈15 km away. HAD3-derived gag is less similar to M. fascicularis from Singapore (SM) and SFVfasW, an M. fascicularis housed at the Washington National Primate Research Center. C) Analysis of pol confirms the relationships (100% of bootstrap samplings) between SFV sequences isolated from humans (HAD3 and HAD38) and those in the corresponding nonhuman primate populations with which they reported contact (AK4, AK19, AK23). HAD3 and HAD38 worked at the same temple site where AK are found. UB1 and UB3 are M. fascicularis from a nearby monkey temple. Scale bars indicate number of nucleotide substitutions per site.