Chlamydiae in oviducts and uteri of repeat breeder pigs

Chlamydial infections of the genital organs cause reproductive failure in female pigs, and the uterus is recognized a target tissue for an infection. In contrast, information on the effect of chlamydiae on the porcine oviduct is patchily and inconclusive, although the bacteria are known to cause severe tubal defects in humans and laboratory animals. The aim of this study was to examine the segments ampulla (A), isthmus (I) and utero-tubal junction of the left (n=20) or both (n=22) oviducts, and uteri (U) from 42 culled repeat breeder pigs for chlamydiae using ompA-PCR, partial ompA gene sequencing, immunohistochemistry (IHC) and microscopy of tissue specimens for histopathology. As revealed by PCR, among a total of 26 chlamydia-positive females, 19 were tested positive in one or more segments of one or both oviducts, 14 were found positive in the uterus, and concomitant infections of both organs were observed in 7 of them. Sequencing of 33 PCR products revealed the following chlamydial species: Chlamydophila (Cp.) psittaci (n=18), Cp. abortus (n=2), Chlamydia (C.) suis (n=10), and C. trachomatis (n=3). Immunopositive staining was observed within the surface epithelium (in A, I, U), stromal tissue (in I, U) and muscular layer (in A, I, U). A total of 24 females had inflamed oviductal segments (in A and/or I) and 36 inflamed uteri. However, there was no relationship between histopathology and results of PCR or IHC. In conclusion, chlamydiae were found to infect oviducts and uteri of pigs. Further studies are required to clarify whether chlamydial infection causes specific histopathology and alters tubal function.