Table 1.
Main genetic differences and associated phenotypic changes of S. Typhimurium D23580 (ST313) in comparison with ST19 strains.
| Gene/prophage | Genetic change(s) compared to ST19 | Phenotypic change(s) compared to ST19 |
|---|---|---|
| pSLT-BT plasmid | Insertion of a composite Tn21-like mobile element (absent in ST19) 11 | CAKSSuW resistance 11 |
| ssel | Pseudogene (insertion of an IS200 element) 11,40,51,54,67 | Hypermigration DCs 54 |
| lpxo | Pseudogene 11,40 | Unknown |
| fliC | Reduced fliC mRNA expression compared to SL1344 and DT104 62 | Reduced NLRC4 inflammasome activation and macrophage death 62 |
| pgtE | SNP at the −12 position of the pgtE TSS compared to 4/74 64 | Increased resistance to complement-mediated serum killing 64 |
| BPT1 | Novel prophage (absent in LT2) 39 | 10,000-fold greater spontaneous phage production 39 |
| BPT5 | Novel prophage (absent in LT2) 39 | Unknown |
| st313-td (bstA) | Novel gene carried by BTP1 propage (absent in LT2) 41 | Increased intra-macrophage replication 41 |
| gtrC | Novel gene carried by BTP1 propage (absent in LT2) 39,42 | Acetylation of rhamnose residues of O-antigen 42 |
| iroC/iroD | Reduced expression in macrophages compared to 4/74 51 | Unknown |
| allP/allB | Pseudogenes (1694 base pairs deletion) 11 | Reduced allantoin degradation 11 |
| ttdA | Pseudogene (nonsense mutation G-A nucleotide change) compared to SL1344 67 | Reduced L- tartrate degradation 67 |
| melR | Pseudogene compared to 4/74 51 | Inability to ferment melibiose 51,70 |
| ratB | Pseudogene (nonsense mutation G-A nucleotide change) compared to SL1344 67 | Possibly reduced cecal colonization and fecal shedding1 68 |
| sopE2 | Reduced sopE2 mRNA expression compared to SL1344 and DT104 62 | Reduced invasion of intestinal epithelial cells 62 |
| macB | Pseudogene 40 | Possibly reduced intestinal colonization2 69 |
| pipD | C-terminal deletion compared to LT2, SL1344 and DT104 11,67 | Reduced enteropathogenicity in bovine ligated ileal loops 67 |
CAKSSuW: A, ampicillin; C, chloramphenicol; K, kanamycin; S, streptomycin; Su, sulfonamide; W,trimethoprim. TSS: Transcriptional Starting Site.
1Phenotype of ΔratB AH12 S. Typhimurium strain (ST19) compared to wild-type AJB715 S. Typhimurium strain (ST19) in CBA/J mice challenge. studies
2Phenotype of ΔmacAB mutant strains derived from S. Typhimurium strain ATCC 14028 (ST19) compared to wild-type S. Typhimurium HA420 strain. (ST19) in BALB/c mice challenge studies