Comparative susceptibility of embryonated hen eggs and pig lung alveolar macrophages to chlamydial infection.

Pig lung alveolar macrophages provided a suitable cell culture system for primary isolation of ovine chlamydia and sustained their growth through several passages. In centrifuged preparations, titres of established strains compared favourably with those obtained in fertile eggs, and in parallel titrations on primary isolation, evidence of chlamydial infection was detectable in macrophages several days earlier than in eggs.