Analysis of some phenotypic traits of feces-borne temperate lambdoid bacteriophages from different immunity groups: a high incidence of cor+, FhuA-dependent phages

A group of previously isolated heterogeneous mEp lambdoid phages (43) from 19 different immunity groups for phage infection was further characterized to gain insight into some phenotypic traits and to assess their relationship with phage λ. Interestingly, the FhuA host receptor was required by the majority of mEp phages (37 out of 43; ~85%). The cor gene, which has been reported to be involved in FhuA-dependent exclusion of lambdoid phages, was also found in most of the FhuA-dependent phages. Accordingly, no cor amplification by PCR was obtained among the six FhuA-independent mEp lambdoid phages. In contrast, it was found that around 25% of the population (10 out of 43 phages) required the specific and essential λ N antitermination function, and the λ site-specific DNA recombination function was observed only in two members (4.6%). Thus, a larger proportion of phages require the FhuA receptor for infection, and this is frequently correlated with the cor gene.