Direct colony PCR was carried out on 100 randomly selected E. coli strains each from the 2019 to 2020 collections, respectively. This became necessary as the mcr‐1 gene has often been shown to exist unexpressed (Fernandes et al., 2016 (link); Hassan et al., 2021 (link); Lentz et al., 2016 ; Terveer et al., 2017 (link)). For each year of collection, 50 strains were selected per source, that is chicken carcasses and faeces. The online research randomizer (version 4.0) computer software was utilized for the selection as all strains were serially numbered. The programme generated random numbers identifying strains to be included. Colonies served as DNA template in the reaction mixtures, with 12.5 μL of DreamTaq Green 2× Master Mix (Thermo Fisher Scientific), 6.5 μL nuclease‐free water and 0.5 μL of each primer solution (F: 5′CGGTCAGTCCGTTTGTTC3′ and R: 5′CTTGGTCGGTCTGTAGGG3′) specific for the mcr‐1 gene. The thermo‐cycling condition was maintained at 94°C 15 min + 25 × (94°C 30 s + 58°C 90 s + 72°C 60 s) + 72°C 10 min, using a MiniAmp Plus Thermal Cycler (Thermo Fisher Scientific). Resulting amplicons were subjected to agarose gel electrophoresis using 1.5% gel in 1× TBE with ethidium bromide. The gels ran for 90 min at 90 V before visualizing the bands (Cavaco et al., 2016 ). The PCR product expected for the mcr‐1 gene was expected to have 309 base pairs.