Molecular Detection and Identification of Chlamydiaceae in the Eyes of Wild and Domestic Ruminant Hosts from Northern Spain.

Andrea Dias-Alves,Oscar Cabezón,Nicole Borel,Jorge Ramón López-Olvera,Santiago Lavín,Xavier Fernández Aguilar,Gregorio Mentaberre

doi:10.3390/pathogens10030383

Abstract

Infections by Chlamydiae are associated with ocular disease in humans and animals. In this study, the presence and diversity of Chlamydia spp. was assessed in diseased and healthy eyes of domestic sheep and wild ruminants that share mountain habitats in northern Spain. The presence of Chlamydia spp. was tested by real-time PCR in 1786 conjunctival swabs collected from both eyes of 893 animals from mountain habitats in northern Spain, and chlamydial species were identified in the positive samples by ArrayTube microarray methods. Chlamydial DNA was detected in 0.6% (CI95% 0.2–1.3) of the Pyrenean chamois (Rupicapra pyrenaica) and 1.4% (CI95% <0.01–8.1) of the sheep (Ovis aries) sampled, with Chlamydia pecorum the only chlamydial species identified. No association of C. pecorum with ocular disease or co-infection with Mycoplasma conjunctivae was found. Further studies on the pathogenesis of infectious keratoconjunctivitis are needed to better understand the ecology of C. pecorum and its possible role as a ruminant pathogen at the wildlife–livestock interface.

Highlights

Introduction published maps and institutional affilChlamydiae are obligate intracellular gram-negative bacteria affecting both humans and animals
Chlamydiaceae was detected in seven swab samples from five of the 893 animals tested (0.6%, CI95%: 0.2–1.3)
Chlamydiaceae has been associated with ocular disease in wild and domestic animals, yet there is scarce knowledge about the frequency and diversity of chlamydial infections in the eyes of ruminants, and its association with ocular clinical signs

Summary

Introduction

Chlamydiae are obligate intracellular gram-negative bacteria affecting both humans and animals. According to the current taxonomy, the Chlamydiaceae family consists of the single genus Chlamydia, which comprises 13 species: Chlamydia (C.) trachomatis, C. pneumoniae, C. psittaci, C. abortus, C. felis, C. pecorum, C. suis, C. gallinacea, C. caviae, C. avium, C. serpentis, C. poikilothermis and C. muridarum [1]. Chlamydiaceae can establish prolonged persistent infections, which are typically asymptomatic, but can cause disease affecting the eyes, the genital tract, the joints or the respiratory tract, and occasionally cause systemic disease [2]. Chlamydial species can cause clinical syndromes of variable severity, suggesting that strain and/or host factors may play a major role in disease outcome [3]. In wild and domestic ruminants, C. abortus, C. psittaci, C. pecorum and. C. pneumoniae are the species most commonly detected in association with disease [4]. C. pneumoniae are the species most commonly detected in association with disease [4]. iations.

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