Screening of virulence gene and establishment of isogenic Chlamydia muridarum clones with different genotype

Abstract:

[Objective] To find difference in whole genome sequence between Chlamydia muridarum standard strain and attenuated strain, screening virulence gene and establish the corresponding isogenic organisms with different genotype, and it may lay a foundation for analyzing pathogenic mechanism. [Methods] C. muridarum strain Nigg G0 and attenuated strain G28 were sequenced by deep sequcencing. virulence-associated genes were identified by whole genome sequencing and alignment. A plaque-forming assay was used to isolate many plaques from both CM.G0 and CM.G28 population organisms. Based on PCR sequencing results from virulence-associated gene, individual clones with different genotype were selected. [Results] Whole genome sequencing and alignment revealed that TC0412, TC0237 and TC0668 gene have much difference between CM.G0 and CM.G28. We had obtained 111 plaque samples by plaque-forming assay, and 56 individual clones from CM.G0 and CM.G28 were selected by PCR identification of TC0412, TC0237 and TC0668. Some clones were matched in three pairs (B3, D1, E1) by TC0412 proteiform, and each pair contained the matched organisms which lack of mutation or carrying 100% mutation of TC0237 and TC0668 gene. [Conclusion] The results showed that TC0412, TC0237 and TC0668 gene may be associated with pathogenicity of C. muridarum. The screened clones which have been matched in pair can be used for next function research of virulence gene.