Intensively kept pigs pre-disposed to chlamydial associated conjunctivitis.

In the present study, ocular chlamydial infections in pigs that originate from two different farming systems were investigated. In particular, the aim was to test pigs with and without clinical ocular symptoms for the presence of Chlamydiaceae and for linked infections with Acanthamoebae spp. possibly acting as vectors for Chlamydia or Chlamydia-like organisms. In a total of 181 pigs, 102 from Germany (GER), representing the intensively kept animals and 79 from Switzerland (CH), which were kept extensively, were screened for the presence of different pathogens by PCR, including a new Chlamydiaceae-specific intergenic spacer rRNA gene PCR. Additionally, results of clinical examination and cytology were compared between the symptomatic and asymptomatic pigs of the two groups. Ocular symptomatic pigs showed a high prevalence of Chlamydia suis in both groups: CH 79%, GER 90%. Only 23% asymptomatic pigs from CH, but 88% asymptomatic pigs from GER were positive for C. suis by PCR. DNA of Chlamydia-like organisms were detected in 19% CH, but only in 2% GER pigs, whereas only 4% CH and 1% GER pigs were also positive for Acanthamoebae spp. A co-infection of Acanthamoebae spp. and C. suis was present in only 3% of the CH but 28% of the GER pigs. In general, the intensively kept pigs in our study seemed to be pre-disposed to ocular chlamydial infection and associated conjunctivitis. Infections with Chlamydia-like organisms alone and in combination with Acanthamoebae played no role for clinical findings within the tested pig groups, whereas a co-infection of Acanthamoebae and C. suis was able to cause serious ocular manifestations in half of the cases of intensively kept pigs being positive for these microorganisms.

Chlamydiales in guinea-pigs and their zoonotic potential.

The aim was to detect and characterize chlamydial infections in guinea-pigs (GP) with ocular disease, study their pathogenicity and zoonotic potential and to test for the presence of Acanthamoebae spp. in GP eyes and to investigate whether they could act as vectors for Chlamydia-like organisms. Overall 126 GP, of which 77 were symptomatic, were screened by clinical examination, cytology, gross pathology, histology, immunohistochemistry, polymerase chain reaction (PCR) and bacteriology. A new Chlamydiaceae-specific intergenic spacer rRNA gene PCR, designed to amplify this segment linking the 16S and 23S regions, was performed. DNA samples were also received from one owner including samples of his cat and rabbit. Guinea-pigs: 48 of 75 symptomatic, but only 11 of 48 asymptomatic GP were positive by PCR for Chlamydophila caviae guinea-pig inclusion conjunctivitis (GPIC) (P < 0.0001). Eighteen of 75 or 15/48, respectively, were positive for DNA from Chlamydia-like organisms. Acanthamoebae-DNA could be found in two GP, of which one was symptomatic. Owner, cat and rabbit: Samples of all three species were positive by PCR for C. caviae GPIC and the owner's one-day disposable contact lenses showed a positive PCR result for the Chlamydia-like organism Parachlamydia acanthamoebae. No Acanthamoebae-DNA could be detected. This study is the first to describe Chlamydia-like organisms in GP and to detect C. caviae GPIC in human, cat and rabbit. Therefore, C. caviae GPIC could pose a zoonotic potential. We believe that the finding of C. caviae GPIC in species other than GP is probably not unique.