Background
Methods
Salmonella isolates and growth conditions
Salmonella growth curves
RNA extraction and RNA-sequencing
Analysis of RNA-sequencing data
Motility assays
Invasion assays
Statistical analysis
Results and discussion
Growth characteristics of MDR S. Typhimurium strains exposed to chlortetracycline or florfenicol
Effect of chlortetracycline and florfenicol exposure on the transcriptome of MDR S. Typhimurium
Gene group | Chlortetracycline | Florfenicol | ||||||
---|---|---|---|---|---|---|---|---|
530 | 1306 | 1434 | 5317 | 530 | 1306 | 1434 | 5317 | |
Attachment | 4.8 ± 0.7 | 5.6 ± 0.9 | 13.2 ± 2.4 | 10.6 ± 1.9 | 4.3 ± 0.5 | 3.9 ± 0.5 | 7.1 ± 0.8 | 3.8 ± 0.3 |
Efflux | 1.9 ± 0.9 | 1.1 ± 0.9 | 3.2 ± 1.5 | 2.8 ± 1.7 | 1.6 ± 0.7 | 0.7 ± 0.6 | 1.5 ± 0.8 | 0.9 ± 0.7 |
Motility | − 10.3 ± 1.4 | − 7.5 ± 1.0 | − 10.6 ± 1.4 | − 9.2 ± 1.0 | − 10.9 ± 1.4 | − 7.9 ± 1.1 | − 9.3 ± 1.3 | − 4.2 ± 0.4 |
SOS response | 0.6 ± 0.3 | 0.8 ± 0.4 | 1.0 ± 0.4 | 1.2 ± 0.5 | 0.3 ± 0.4 | 0.6 ± 0.4 | 0.5 ± 0.4 | 0.6 ± 0.4 |
SPI-1 | 1.4 ± 0.4 | 2.3 ± 0.4 | 13.7 ± 1.9 | 10.9 ± 1.1 | 0.1 ± 0.5 | 0.5 ± 0.4 | 6.5 ± 0.9 | 4.5 ± 0.5 |
SPI-2 | 5.4 ± 0.8 | 5.6 ± 1.0 | 16.7 ± 3.3 | 12.3 ± 2.3 | 3.6 ± 0.7 | 4.3 ± 0.7 | 9.6 ± 2.0 | 4.5 ± 0.7 |
SPI-3 | 15.8 ± 11.9 | 7.8 ± 4.0 | 23.6 ± 17.8 | 23.1 ± 15.9 | 9.9 ± 7.4 | 3.4 ± 1.8 | 11.9 ± 8.1 | 11.5 ± 8.5 |
SPI-4 | − 0.2 ± 0.7 | 0.7 ± 0.7 | 14.6 ± 5.9 | 14.3 ± 4.0 | − 1.3 ± 1.1 | − 3.0 ± 1.5 | 2.0 ± 0.3 | 1.5 ± 0.1 |
SPI-5 | 3.6 ± 2.9 | 2.2 ± 3.6 | 20.2 ± 12.9 | 9.8 ± 8.2 | 2.9 ± 3.0 | 1.2 ± 3.2 | 6.9 ± 5.5 | 2.6 ± 1.9 |
Attachment genes
SPI-1
SPI-2
SPI-3
SPI-4
SPI-5
Motility and SOS response genes
Gene ontology analysis of differentially expressed genes
Gene ontology term | Chlortetracycline | Florfenicol | ||||||
---|---|---|---|---|---|---|---|---|
530 | 1306 | 1434 | 5317 | 530 | 1306 | 1434 | 5317 | |
Cell adhesion (GO:0007155) | NS | NS | 2.6 | 2.4 | NS | NS | 2.3 | 2.8 |
Biological adhesion (GO:0022610) | NS | NS | 2.6 | 2.4 | NS | NS | 2.3 | 2.8 |
Multi-organism process (GO:0051704) | 1.7 | NS | NS | NS | NS | NS | NS | NS |
Pathogenesis (GO:0009405) | NS | 1.8 | 2.3 | 2.2 | NS | NS | 2.1 | 3.0 |
Interspecies interaction between organisms (GO:0044419) | NS | 1.8 | 2.1 | 2.0 | NS | NS | 1.9 | 2.6 |
Multi-organism process (GO:0051704) | NS | 1.7 | 1.9 | 2.0 | NS | NS | 1.8 | 2.4 |
Pilus organization (GO:0043711) | 2.7 | NS | NS | NS | 2.8 | NS | NS | 3.4 |
Protein secretion (GO:0009306) | NS | NS | NS | NS | NS | NS | NS | 2.8 |
Secretion by cell (GO:0032940) | NS | NS | NS | NS | NS | NS | NS | 2.7 |
Peptide secretion (GO:0002790) | NS | NS | NS | NS | NS | NS | NS | 2.8 |
Transmembrane transport (GO:0055085) | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 | 1.6 |
Transport (GO:0006810) | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.4 |
Establishment of localization (GO:0051234) | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.3 | 1.4 |
Localization (GO:0051179) | 1.3 | 1.3 | 1.3 | 1.2 | 1.3 | 1.2 | 1.3 | 1.4 |