Pig as a reservoir of CRISPR type TST4 Salmonella enterica serovar Typhimurium monophasic variant during 2009–2017 in China

Figures & data

Figure 1. The CRISPR type and phylogenic relationship of 173 Salmonella Typhimurium and its monophasic variant isolates. (A) The CRISPR type for each strain is represented by spacers arrangement in CRISPR1 (left) and CRISPR2 (right) locus. Each unique spacer is represented by a unique combination of background colour with the colour and shape of the object in the foreground. Name of the spacers are labelled on the top of each spacers. And the frequency of each allelic type is listed on the left side of the CRISPR allele. The TSTs (Typhimurium sequence types) are derived from the combination of CRISPR 1 and CRISPR alleles. (B) The minimum spanning phylogenetic tree built from the CRISPR allelic profiles of 173 Salmonella Typhimurium and Salmonella 4,[5],12:i:- isolates. The size of each circle is proportional to the number of isolates in this circle and isolates in the same circle share the same CRISPR type. All TSTs are labelled and the origins of isolates are indicated with unique colours on the right side. The left side is composed of non-ST34 Salmonella Typhimrium isolates, while the right side includes only ST34 isolates of Salmonella Typhimurium and Salmonella 4,[5],12:i:- isolated mainly from humans and pigs. (C) The maximum-parsimony approach was performed to reveal the genetic relationship of 34 TSTs. Two lineages and four sub-lineages clearly showed that Lineage II and IB-1 was only Salmonella Typhimurium isolates, while Lineage IA was occupied by Salmonella 4,[5],12:i:-. Only Lineage IB-2 was mixed by both serotypes.