Endemic and Emerging Chlamydial Infections of Animals and Their Zoonotic Implications

Moredun Research Institute, Pentlands Science Park, Edinburgh, UK.
Transboundary and Emerging Diseases (Impact Factor: 2.94). 11/2011; 59(4):283-91. DOI: 10.1111/j.1865-1682.2011.01274.x
Source: PubMed


The Chlamydiae are a diverse group of obligate intracellular Gram-negative bacteria that are known to infect a wide variety of host species and are responsible for a wide range of diseases in animals and man. Many of these organisms have been extensively characterized and their zoonotic implications recognized. Studies of human disease first provided evidence for the disease-causing potential of Chlamydia-related bacteria; however, there is now increasing evidence that a number of these organisms may also be the causative agents for a number of pathogenic conditions of livestock that had previously remained undiagnosed. The aim of this review is to draw together the evidence for the role of the newly emerging chlamydial infections in livestock disease, the current understanding of their roles in human disease and highlight the potential for zoonotic transmission.

Download full-text


Available from: David Longbottom,
  • [Show abstract] [Hide abstract]
    ABSTRACT: Changes in the taxonomy of the order Chlamydiales, after its separation from the order Rickettsiales, were presented. These changes resulted in the recognition of the following families: Chlamydiaceae, Chlavichlamydiaceae, Criblamydiaceae, Parachlamydiaceae, Piscichlamydiaceae, Rhabdochlamydiaceae, Simkaniaceae, and Waddliaceae. Other described changes concerned particularly the family Chlamydiaceae. Its genus Chlamydia was divided into Chlamydia and Chlamydophila. However, in the following years, a revision to the single original genus was made, based upon phylogenetic analysis of 16S and 23S rRNA genes of the strains belonging to these two taxonomic units. The review also discusses other families outside the family Chlamydiaceae, which contain so-called Chlamydia-related or Chlamydia-like organisms. Members of each family share a 16S rDNA gene sequence similarity >90%. Furthermore, characterisation of the pathogenecity is presented, focusing especially on the representatives of the family Chlamydiaceae, which cause animal infections, and describing their zoonotic potential. Available data on this topic, connected with the representatives of other families, were mentioned.
    Bulletin- Veterinary Institute in Pulawy 01/2012; 56(3). DOI:10.2478/v10213-012-0047-8 · 0.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The outbreak of chlamydiosis in one of the western provinces of Poland, was diagnosed accidentally as a concurrent infection in a commercial laying hen flock during an outbreak of fowl pox. For histological examination, skin and subcutaneous tissue samples from lesions on heads of the birds were collected. Swabs from throat and trachea have been examined by nested PCR, real-time PCR, and partial ompA sequencing. Detailed electron microscopy analysis revealed fowl pox intracytoplasmic inclusions, called Bollinger bodies, and the presence of other intracytoplasmic inclusions; specific for Chlamydia sp. Results of nested PCR confirmed the presence of Chlamydiaceae sp. in two tested samples. Surprisingly, one of the two Chlamydiaceae-positive cases turned out to be infected with a non-classified strain. Results of real-time PCR and sequencing confirmed the presence of a new Chlamydia species that has not been found in Poland to date. Partial sequencing and BLAST analysis of ompA gene sequence confirmed the highest homology to non-classified poultry strains of Chlamydia sp. that were previously detected in Germany and France. The zoonotic potential and the exact taxonomic status of this atypical strain have yet to be defined.
    Bulletin- Veterinary Institute in Pulawy 03/2013; 57(1):25-28. DOI:10.2478/bvip-2013-0005 · 0.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chlamydia spp. are obligate intracellular bacteria distributed globally, known to cause various forms of diseases in animals and humans. To date, there is limited information about the seroprevalence of Chlamydia and the risk factors associated with Chlamydia infection in dogs in the world. In the present study, a serological survey was undertaken to examine the seroprevalence and risk factors associated with dog chlamydiosis in Yunnan Province, southwestern China. A total of 591 dogs were sampled, antibodies to Chlamydia were determined by indirect hemagglutination assay (IHA). The overall seroprevalence was estimated at 17.6%. The risk factors associated with seroprevalence were determined by a multivariate logistic regression analysis. Gender and age of dogs were not significant in the logistic regression analysis (P>0.05) and left out of the final model. Type and geographical origin of dogs were considered as main risk factors associated with Chlamydia infection, stray dogs (31.37%) were more than 16 times (OR=16.167, 95% CI= 6.283-41.599, P<0.01) at risk of acquiring the infection compared to the police dogs (7.62%), while pet dogs (14.41%) had a 3 times (OR=2.968, 95% CI=1.349-6.529, P=0.007) higher risk. Positive dogs were found in 5 districts of Yunnan Province with prevalence ranging from 2.56% to 31.67% except Diqing (0/56). Dogs in Kunming (20.21%) had a 9 times higher risk of being seropositive compared to dogs in Lijiang (2.56%) (OR=9.057, 95%CI=1.211-67.714, P=0.032), although no regional differences were found in other 4 administrative divisions compared to Lijiang (P>0.05). Our study revealed a widespread and high prevalence of Chlamydia infection in dogs in Yunnan Province, southwestern China, with higher exposure risk in stray dogs and distinct geographical distribution. These findings suggests the potential importance of dogs in the transmission of zoonotic Chlamydia infection, and thus Chlamydia should be taken into consideration in diagnosing dog diseases.
    Acta tropica 10/2013; 130(1). DOI:10.1016/j.actatropica.2013.09.027 · 2.27 Impact Factor
Show more