Isolation of chlamydia in keratoconjunctivitis

Two isolates, identified as Chlamydia (neorickettsia) were obtained from the lacrimal secretion of calves with an acute infection on two of a total of four investigated farms with a record of infectious keratoconjunctivitis. In about 70% of the calves that survived there were complement-fixing antibodies against the neorickettsial antigen, the titers ranging from 1:8 to 1:64. Calves that yielded the causative agent were investigated in terms of the antibody dynamics. In the remaining herds no specific antibodies were demonstrated in animals that had survived. One of the isolated strains was used to infect (via the external camera oculi) a rabbit. Acute keratoconjunctivitis followed, and the blood serum of the rabbit was found to contain complement-fixing antibodies of a titer within the 1:8-1:16 range from the 30th day on. A neorickettsial strain was also isolated from the ocular secretion of a dog with serofibrinous keratoconjunctivitis, and this was regarded as a rarely encountered finding.