How to cite this article: Vet. Res. (2008) 39:56
DOI: 10.1051/vetres:2008032

Identification and characterisation of coding tandem repeat variants in incA gene of Chlamydophila pecorum

Khalil Yousef Mohamad¹, Abdessalem Rekiki¹, Garry Myers², Patrik M. Bavoil³ and Annie Rodolakis<sup>1

1</sup>  INRA, UR1282, Infectiologie Animale et Santé Publique, Centre de recherche de Tours, F-37380 Nouzilly, France
²  Institute for Genome Science, University of Maryland, Baltimore, MD, USA
³  Department of Biomedical Sciences, University of Maryland, Baltimore, MD, USA

Received 5 March 2008; accepted 23 July 2008; published online 25 July 2008

Abstract - Bacteria of the family Chlamydiaceae are obligate intracellular pathogens of human and animals. Chlamydophila pecorum is associated with different pathological conditions in ruminants, swine and koala. To characterize a coding tandem repeat (CTR) identified at the 3' end of incA gene of C. pecorum, 51 strains of different chlamydial species were examined. The CTR were observed in 18 of 18 tested C. pecorum isolates including symptomatic and asymptomatic animals from diverse geographical origins. The CTR were also found in two strains of C. abortus respectively isolated from faeces from a healthy ewe and from a goat belonging to asymptomatic herds, but were absent in C. abortus strains isolated from clinical disease specimens, and in tested strains of C. psittaci, C. caviae, C. felis and C. trachomatis. The number of CTR repeats is variable and encode several motifs that are rich in alanine and proline. The CTR-derived variable structure of incA, which encode the Chlamydiaceae-specific type III secreted inclusion membrane protein, IncA, may be involved in the adaptation of C. pecorum to its environment by allowing it to persist in the host cell.

Key words: Chlamydophila pecorum / incA gene / coding tandem repeats

Corresponding author: rodolaki@tours.inra.fr

© INRA, EDP Sciences 2008