Volume 5, Number 1—February 1999
Research
Dual and Recombinant Infections: An Integral Part of the HIV-1 Epidemic in Brazil
Artur Ramos*†, Amilcar Tanuri†, Mauro Schechter†, Mark A. Rayfield*, Dale J. Hu*, Maulori C. Cabral†, Claudiu I. Bandea*, James Baggs‡, and Danuta Pieniazek*
Table 1
Sensitivity of detection of HIV-1 dual infections caused by viruses of subtypes B and F
| No. of viral subtype |
Ratio F:B | No. of experiments | AluI digestion patterns of prt |
|||
|---|---|---|---|---|---|---|
| F | B | B | F | B&F | ||
| 100 | 100 | 1:1 | 1 | – | – | + |
| 50 | 50 | 1:1 | 4 | – | – | + |
| 25 | 25 | 1:1 | 4 | – | + (1) | + (3) |
| 10 | 10 | 1:1 | 4 | – | – | + |
| 5 | 5 | 1:1 | 4 | – | + (3) | + (1) |
| 100 | 5 | 20:1 | 2 | – | + (1) | + (1) |
| 100 | 10 | 10:1 | 2 | – | + (1) | + (1) |
| 100 | 25 | 4:1 | 2 | – | + | – |
| 100 | 50 | 2:1 | 2 | – | – | + |
| 5 | 100 | 1:20 | 1 | – | – | + |
| 10 | 100 | 1:10 | 1 | – | – | + |
| 25 | 100 | 1:4 | 1 | – | – | + |
| 50 | 100 | 1:2 | 1 | – | – | + |
| 100 | 0 | 3 | – | + | – | |
| 50 | 0 | 3 | – | + | – | |
| 25 | 0 | 3 | – | + | – | |
| 10 | 0 | 3 | – | + | – | |
| 5 | 0 | 2 | – | + | – | |
| 0 | 100 | 3 | + | – | – | |
| 0 | 50 | 2 | + | – | – | |
| 0 | 25 | 3 | + | – | – | |
| 0 | 10 | 3 | + | – | – | |
| 0 | 5 | 3 | + | – | – | |
Absence (-) and presence (+) of AluI digestion pattern of prt characteristic for subtype B, subtype F, and combination of subtypes B and F (Figure 1). The cloned proviral DNA of HIV-1 subtypes B and F spanning a 1444-bp fragment from p24 gag to rt was used for the nested PCR amplification of prt. Amplified products were digested with AluI restriction enzyme, and the presence of two digestion patterns was analyzed on a 10% polyacrylamide gel by ethidium-bromide staining.
