Hongxia Bao1,2,3, Jian-Hua Zhao1,2,3, Songling Zhu1,2,3, Shuang Wang4, Jianjuan Zhang1,2,3, Xiao-Yu Wang1,2,3, Bing Hua1,2,3, Chang Liu1,2,3, Huidi Liu1,2,3, Shu-Lin Liu1,2,3,5. 1. Systemomics Center, College of Pharmacy & Genomics Research Center, Harbin Medical University, Harbin, PR China. 2. HMU-UCCSM Centre for Infection & Genomics, Harbin Medical University, Harbin, PR China. 3. Translational Medicine Research & Cooperation Center of Northern China, Heilongjiang Academy of Medical Sciences, Harbin, PR China. 4. Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, Harbin, PR China. 5. Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, T2N 1N4, Canada.
Abstract
AIM: Type VI secretion systems (T6SS) play key roles in bacterial pathogenesis, but their evolutionary features remain largely unclear. In this study, we conducted systematic comparisons among the documented T6SSs in Salmonella and determined their structural diversity, phylogenetic distribution and lineage-specific properties. MATERIALS & METHODS: We screened 295 Salmonella genomes for 13 T6SS core components by hidden Markov models and identified 363 T6SS clusters covering types i1, i2, i3 and i4a. RESULTS: Type i3 and i4a T6SSs were restricted to Salmonella enterica subspecies enterica and Salmonella bongori, respectively. whereas type i2 T6SSs were conserved between S. enterica subspecies, arizonae and diarizonae. S. enterica subspecies salamae, indica and houtenae harbored only type i1 T6SSs, which had wide distribution and high sequence diversity. CONCLUSION: The diverse Salmonella T6SSs have undergone purifying selection pressures during the bacterial evolution and may be involved in host adaptation.
AIM: Type VI secretion systems (T6SS) play key roles in bacterial pathogenesis, but their evolutionary features remain largely unclear. In this study, we conducted systematic comparisons among the documented T6SSs in Salmonella and determined their structural diversity, phylogenetic distribution and lineage-specific properties. MATERIALS & METHODS: We screened 295 Salmonella genomes for 13 T6SS core components by hidden Markov models and identified 363 T6SS clusters covering types i1, i2, i3 and i4a. RESULTS: Type i3 and i4a T6SSs were restricted to Salmonella enterica subspecies enterica and Salmonella bongori, respectively. whereas type i2 T6SSs were conserved between S. enterica subspecies, arizonae and diarizonae. S. enterica subspecies salamae, indica and houtenae harbored only type i1 T6SSs, which had wide distribution and high sequence diversity. CONCLUSION: The diverse Salmonella T6SSs have undergone purifying selection pressures during the bacterial evolution and may be involved in host adaptation.
Entities:
Keywords:
; type VI secretion system; genomic evolution
Authors: Fernando A Amaya; Carlos J Blondel; María F Barros-Infante; Dácil Rivera; Andrea I Moreno-Switt; Carlos A Santiviago; David Pezoa Journal: Front Microbiol Date: 2022-02-10 Impact factor: 5.640