A, PCR products amplified using the specific primers for K. pneumoniae TEM gene (Lane M, gene ruler 100-bp DNA ladder (Thermo Fisher Scientific); Lanes 1 to 7, PCR products of the positive samples); B, PCR products amplified using the specific primers for K. pneumoniae SHV gene (Lanes 1, 2 and 6, positive samples; Lanes 3 to 5, negative samples).