Plasmid-mediated transformation tropism of chlamydial biovars.
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.
Laboratory of Intracellular Parasites, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA; State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China.
Lihua
L
Song
John H
JH
Carlson
Bing
B
Zhou
Kimmo
K
Virtaneva
William M
WM
Whitmire
Gail L
GL
Sturdevant
Stephen F
SF
Porcella
Grant
G
McClarty
Harlan D
HD
Caldwell
D000818:Animals; D023502:Chlamydia muridarum / Q000235:genetics*; D002692:Chlamydia trachomatis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D022761:Gene Transfer, Horizontal; D005822:Genetic Vectors; D058507:Host Specificity; D006801:Humans; D051379:Mice; D010957:Plasmids; D014169:Transformation, Bacterial; D037521:Virulence Factors / Q000096:biosynthesis
D037521:Virulence Factors
Chlamydiae; plasmid; transformation; tropism