Detection of drug-resistant viruses in the BTP3-based filter method.

<p>(A) 100 μM BTP3-Neu5Ac supplemented with or without 10 μM NAIs was added directly onto the influenza virus-loaded filter membranes. After 15 min at 56°C, BTP3 was visualized with a handheld UV flashlight and NAI susceptibility was evaluated by comparing the fluorescent images for NAI (-) and NAI-supplemented samples. NAI susceptibility of seven influenza virus strains was assessed for each NAI. (B) Fluorescence patterns of agents that may cause false-positive results. MuV, <i>S</i>. <i>pneumoniae</i>, and HPIV-1 with known titres were loaded onto the filter membranes and BTP3-Neu5Ac reaction was carried out as described in (A). OV, PV, ZV, and LV represent oseltamivir, peramivir, zanamivir, and laninamivir, respectively.