The presence of more colonies growing inside the lytic halos of vB_KpnS-VAC35_ad15_m compared to the infection established by vB_KpnS-VAC35_ad15 suggested that mucin either affected the phage-infection capacity, or it enhanced the bacterial defence to the phage [as it has already been documented in the literature for different microorganisms (Green et al., 2021; de Freitas Almeida et al., 2022)]. This evidence concerns the gene MUC5AC and infection.