Genomic and phenotypic comparison of two Salmonella Typhimurium strains responsible for consecutive salmonellosis outbreaks in New Zealand

International Journal of Medical Microbiology

卷:311

Jackie Benschop¹  David T.S. Hayman²  Marian Price-Carter²  Holly Gray³  Nigel P. French⁴  Sara Burgess⁵  Jonathan C. Marshall⁶  Philip E. Carter⁶  Leah Toombs-Ruane⁶  Anne C. Midwinter⁶  Patrick J. Biggs⁶  Samuel J. Bloomfield⁷ 

[1] Corresponding author.;

[2] School of Fundamental Science, Massey University, Palmerston North, 4410, New Zealand;

[3] Te Pūnaha Matatini, Centre of Research Excellence for Complex Systems, New Zealand;

[4] AgResearch, Hopkirk Research Institute, Massey University, Palmerston North, 4410, New Zealand;

[5] Institute of Environmental Science of Research, 34 Kenepuru Drive, Kenepuru, Porirua, 5022, New Zealand;

[6] Massey University's Molecular Epidemiology and Public Health Laboratory, Hopkirk Research Institute, Massey University, Palmerston North, 4410, New Zealand;

[7] Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, UK;

关键词: Genomics;    Salmonella;    Phage;    Epidemic;    Plasmid;   

DOI  :  

来源: DOAJ

【 摘 要 】

Salmonella enterica serovar Typhimurium DT160 was the predominant cause of notified human salmonellosis cases in New Zealand from 2000 to 2010, before it was superseded by another S. Typhimurium strain, DT56 variant (DT56v). Whole genome sequencing and phenotypic testing were used to compare 109 DT160 isolates with eight DT56v isolates from New Zealand animal and human sources. Phylogenetic analysis provided evidence that DT160 and DT56v strains were distantly related with an estimated date of common ancestor between 1769 and 1821. The strains replicated at different rates but had similar antimicrobial susceptibility profiles. Both strains were resistant to the phage expressed from the chromosome of the other strain, which may have contributed to the emergence of DT56v. DT160 contained the pSLT virulence plasmid, and the sseJ and sseK2 genes that may have contributed to the higher reported prevalence compared to DT56v. A linear pBSSB1-family plasmid was also found in one of the DT56v isolates, but there was no evidence that this plasmid affected bacterial replication or antimicrobial susceptibility. One of the DT56v isolates was also sequenced using long-read technology and found to contain an uncommon chromosome arrangement for a Typhimurium isolate. This study demonstrates how comparative genomics and phenotypic testing can help identify strain-specific elements and factors that may have influenced the emergence and supersession of bacterial strains of public health importance.

【 授权许可】

Unknown