A primary study on genes with selected mutations by in vitro passage of Chlamydia muridarum strains

• Published in: Pathogens and disease 2019-04, Vol.77 (3)
• Main Authors: Zhou, Zhou, Liu, Na, Wang, Yingzi, Emmanuel, Arthur Wirekoh, You, Xiaoxing, Liu, Jiulin, Li, Zhongyu, Wu, Yimou, Zhong, Guangming
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Load; Centrifugation; Chlamydia; Chlamydia Infections - microbiology; Chlamydia Infections - pathology; Chlamydia muridarum; Chlamydia muridarum - genetics; Chlamydia muridarum - growth & development; Chlamydia muridarum - pathogenicity; Dependence; Disease Models, Animal; Female; Gene sequencing; Genes; Genes, Bacterial; Genetic Variation; Genomes; Genotype; Genotypes; HeLa Cells; Humans; Mice, Inbred C3H; Mutation; Point mutation; Reproductive Tract Infections - microbiology; Reproductive Tract Infections - pathology; Serial Passage; Sexually transmitted diseases; STD; Strains (organisms); Vagina - microbiology; Virulence; Whole Genome Sequencing
• ISSN: 2049-632X; 2049-632X
• DOI: 10.1093/femspd/ftz017

ABSTRACT Objective This study is to investigate the functions of newly discovered genes in Chlamydia muridarum (C. muridarum) strains with single gene differences. Methods Using whole genome sequencing and plaque formation assays, C. muridarum parental and passaging strains were established, and the isogenic clones expressing certain genotypes were isolated. Strains with single gene differences were obtained. Based on prediction, the valuable strains with single gene differences of tc0412, tc0668 or tc0237 were subjected to the in vitro and in vivo experiments for biological characterization and virulence analysis. Results Insertional -472840T mutation of the tc0412 gene (T28T/B3 type) matching with the nonmutant tc0668 gene and tc0237 gene with point mutations G797659T (Q117E) might slow the growth of Chlamydia due to the lack of a plasmid. The nonmutant tc0668 in the strain might induce a high incidence of hydrosalpinx in mice, while tc0668 with a G797659T point mutation was significantly attenuated. Compared with the nonmutant tc0237, the strains containing mutant tc0237 were characterized by reduced centrifugation dependence during infection. Conclusion The identification and characterization of these genes might contribute to the comprehensive understanding of the pathogenic mechanism of Chlamydia. Newly discovered genes in C. muridarum