To further confirm the crucial role of the δ subunit in lethal infection, we constructed the complemented strain atp16Δ/ATP16 and the overexpressed strain Atp16 O/E by reintroducing an ATP16 gene ORF into the ATP16 locus of atp16Δ/Δ and introducing an ATP16 gene ORF into the ADH1 locus of WT. Here, ADH1A is linked to infection.