Submitted to: International Meeting of the European Society for Chlamydia Research
Publication Type: Proceedings
Publication Acceptance Date: 6/25/1996
Publication Date: N/A
Technical Abstract: Chlamydial isolates were recovered from 1- to 6-week-old pigs with pneumonia, enteritis, and/or conjunctivitis from two herds. Using PCR-RFLP, the isolates have been determined to represent six distinctive strains. Four of the isolates representing four strains have been used to inoculate 4- to 7-day-old gnotobiotic piglets. Previously, one of the isolates had been reported to produce pneumonia when inoculated intratracheally. In the current study, two more of the isolates were fed orally, mixed in the milk formula, and a fourth isolate was placed in the conjunctival sac. The pigs given chlamydiae orally developed a mild to severe enteritis which lasted 7 to 10 days. The primary lesions were moderate to severe villus atrophy of the duodenum, ileum, and jejunum. The ileum was the most commonly infected area; however, in severe cases the entire small intestine and the colon were involved. Conjunctival sac inoculation produced mild to moderate conjunctivitis. Follicular development (seen with endemic trachoma) was not observed. However, the lesions were similar to those described in the human infant following infection at birth with venereal strains. Chlamydial infections in swine are proving to be an excellent model for studying the pathogenesis of chlamydiae in humans. The swine isolates are biologically more similar to the human strains than any other strains from non-human animals. They produce a disease syndrome in young pigs that is similar to that seen in infants following infection at the time of birth.