Plasmid-mediated transformation tropism of chlamydial biovars

• Published in: Pathogens and disease 2014-03, Vol.70 (2), p.189-193
• Main Authors: Song, Lihua, Carlson, John H., Zhou, Bing, Virtaneva, Kimmo, Whitmire, William M., Sturdevant, Gail L., Porcella, Stephen F., McClarty, Grant, Caldwell, Harlan D.
• Format: Article
• Language: English
• Subjects: Animals; Chlamydia muridarum - genetics; Chlamydia trachomatis; Chlamydia trachomatis - genetics; Chlamydiae; Gene Expression Regulation, Bacterial; Gene Transfer, Horizontal; Genetic Vectors; Host Specificity; Humans; Mice; plasmid; Plasmids; transformation; Transformation, Bacterial; tropism; Virulence Factors - biosynthesis
• ISSN: 2049-632X; 2049-632X
• DOI: 10.1111/2049-632X.12104

Abstract Chlamydia trachomatis and C. muridarum are human and mouse pathogens, respectively, which show high conservation of gene order and content. Both species contain a common 7.5-kb plasmid that is an important virulence factor. Recently described transformation systems have been used to characterize C. trachomatis L2 plasmid gene functions; however, similar studies have not been reported for C. trachomatis ocular tropic serovar A or the mouse strain, C. muridarum. Here, we have conducted genetic experiments with C. trachomatis serovar A and C. muridarum and report the following: (1) successful transformation of C. muridarum and C. trachomatis serovar A is restricted to a shuttle vector with a C. muridarum or C. trachomatis serovar A plasmid backbone, respectively; (2) transformation of plasmid-deficient C. muridarum with the C. muridarum-based shuttle vector complement glycogen accumulation and inclusion morphology; and (3) C. muridarum plasmid-encoded Pgp4 is a regulator of chromosomal (glgA) and plasmid (pgp3) virulence genes. In summary, our findings show a previously unrecognized and unexpected role for the chlamydial plasmid in its transformation tropism and confirm the plasmids regulatory role of virulence genes in C. muridarum. This study is the first to show that plasmid mediated transformation of chlamydiae is biovar-specific; a tropism that provides experimental evidence for a co-evolutionary relationship between plasmid and chromosomal genes. This study is the first to show that plasmid mediated transformation of chlamydiae is biovar-specific; a tropism that provides experimental evidence for a co-evolutionary relationship between plasmid and chromosomal genes.