title: Host adaptation of Chlamydia pecorum towards low virulence evident in co-evolution of the ompA, incA, and ORF663 Loci.
abstract: Chlamydia (C.) pecorum, an obligate intracellular bacterium, may cause severe diseases in ruminants, swine and koalas, although asymptomatic infections are the norm. Recently, we identified genetic polymorphisms in the ompA, incA and ORF663 genes that potentially differentiate between high-virulence C. pecorum isolates from diseased animals and low-virulence isolates from asymptomatic animals. Here, we expand these findings by including additional ruminant, swine, and koala strains. Coding tandem repeats (CTRs) at the incA locus encoded a variable number of repeats of APA or AGA amino acid motifs. Addition of any non-APA/AGA repeat motif, such as APEVPA, APAVPA, APE, or APAPE, associated with low virulence (P<10-4), as did a high number of amino acids in all incA CTRs (P = 0.0028). In ORF663, high numbers of 15-mer CTRs correlated with low virulence (P = 0.0001). Correction for ompA phylogram position in ORF663 and incA abolished the correlation between genetic changes and virulence, demonstrating co-evolution of ompA, incA, and ORF663 towards low virulence. Pairwise divergence of ompA, incA, and ORF663 among isolates from healthy animals was significantly higher than among strains isolated from diseased animals (P≤10-5), confirming the longer evolutionary path traversed by low-virulence strains. All three markers combined identified 43 unique strains and 4 pairs of identical strains among all 57 isolates tested, demonstrating the suitability of these markers for epidemiological investigations.
authors.affiliation: INRA, UR1282 Infectiologie Animale et Santé Publique, Nouzilly, France.
authors.forename: Khalil Yousef
authors.initials: KY
authors.lastname: Mohamad
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, United States of America.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kaltenboeck
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, United States of America.
authors.forename: Kh Shamsur
authors.initials: KhS
authors.lastname: Rahman
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini", National Reference Laboratory for Animal Chlamydioses, Sezione Diagnostica di Pavia, Pavia, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Magnino
authors.affiliation: Friedrich-Loeffler-Institut Jena, OIE and National Reference Laboratory for Chlamydiosis, Jena, Germany.
authors.forename: Konrad
authors.initials: K
authors.lastname: Sachse
authors.affiliation: INRA, UR1282 Infectiologie Animale et Santé Publique, Nouzilly, France.
authors.forename: Annie
authors.initials: A
authors.lastname: Rodolakis
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D005075:Biological Evolution; D002689:Chlamydia / Q000378:metabolism / Q000472:pathogenicity*; D002690:Chlamydia Infections / Q000235:genetics / Q000378:metabolism; D048368:Phascolarctidae; D010750:Phosphoproteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013552:Swine; D020080:Tandem Repeat Sequences / Q000235:genetics; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C094163:IncA protein, bacteria; D010750:Phosphoproteins; C078167:OMPA outer membrane proteins
references.citation: Vet J. 2011 Sep;189(3):257-67
references.pmid: 20980178
references.citation: Am J Vet Res. 1992 Sep;53(9):1482-7
references.pmid: 1358014
references.citation: Vet J. 2008 Feb;175(2):202-11
references.pmid: 17317243
references.citation: Vet Microbiol. 2009 Mar 16;135(1-2):175-80
references.pmid: 18930605
references.citation: Infect Genet Evol. 2008 Mar;8(2):171-81
references.pmid: 18242149
references.citation: Comp Immunol Microbiol Infect Dis. 1996 Feb;19(2):155-61
references.pmid: 8814978
references.citation: Acta Vet Scand. 2008 Sep 26;50:39
references.pmid: 18822135
references.citation: Vet Microbiol. 1995 Jul;45(2-3):93-119
references.pmid: 7571380
references.citation: Mol Biol Evol. 2013 Dec;30(12):2725-9
references.pmid: 24132122
references.citation: Clin Infect Dis. 1998 Feb;26(2):314-22
references.pmid: 9502448
references.citation: Theriogenology. 2006 Jun;65(9):1750-8
references.pmid: 16280160
references.citation: Ann Rech Vet. 1976;7(2):195-205
references.pmid: 1035841
references.citation: BMC Microbiol. 2008 Dec 10;8:218
references.pmid: 19077205
references.citation: PLoS One. 2012;7(9):e44961
references.pmid: 23024776
references.citation: J Bacteriol. 2011 Jul;193(14):3690
references.pmid: 21571992
references.citation: Vet Ital. 2013 Jan-Mar;49(1):119-22
references.pmid: 23564593
references.citation: Proc Natl Acad Sci U S A. 1996 Oct 1;93(20):11121-5
references.pmid: 8855319
references.citation: Arthritis Rheum. 1967 Feb;10(1):1-12
references.pmid: 6066932
references.citation: BMC Genomics. 2014 Jan 14;15:23
references.pmid: 24417976
references.citation: Infect Immun. 2000 Feb;68(2):680-7
references.pmid: 10639433
references.citation: Aust Vet J. 2011 Oct;89(10):409-12
references.pmid: 21933169
references.citation: Infect Genet Evol. 2008 Dec;8(6):764-71
references.pmid: 18707024
references.citation: J Zoo Wildl Med. 2005 Mar;36(1):100-2
references.pmid: 17315464
references.citation: Nucleic Acids Res. 1999 Jan 15;27(2):573-80
references.pmid: 9862982
references.citation: J Clin Microbiol. 2007 Apr;45(4):1185-9
references.pmid: 17301282
references.citation: Vet Res. 2008 Nov-Dec;39(6):56
references.pmid: 18651990
references.citation: Vet Microbiol. 2009 Mar 16;135(1-2):22-30
references.pmid: 18950965
references.citation: Vet Res. 2010 May-Jun;41(3):27
references.pmid: 19995513
references.citation: J Clin Microbiol. 2013 Aug;51(8):2625-32
references.pmid: 23740730
references.citation: BMC Microbiol. 2011 Apr 18;11:77
references.pmid: 21496349
references.citation: Theriogenology. 2008 Jun;69(9):1061-9
references.pmid: 18374406
references.citation: Bioinformatics. 2009 May 1;25(9):1189-91
references.pmid: 19151095
references.citation: Vet Microbiol. 2010 Jul 14;143(2-4):424-8
references.pmid: 19969431
references.citation: J Bacteriol. 1993 Jan;175(2):487-502
references.pmid: 8419295
references.citation: Res Vet Sci. 1989 Jan;46(1):34-9
references.pmid: 2922503
references.citation: BMC Microbiol. 2008 Feb 28;8:42
references.pmid: 18307777
references.citation: J Clin Microbiol. 2004 Dec;42(12):5664-72
references.pmid: 15583297
references.citation: Vet Microbiol. 1999 Mar 19;65(4):255-64
references.pmid: 10223324
references.citation: BMC Vet Res. 2011 Jun 16;7:29
references.pmid: 21679409
references.citation: J Gen Microbiol. 1991 Nov;137(11):2525-30
references.pmid: 1686054