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Quinolone-resistance in Salmonella is associated with decreased mRNA expression of virulence genes invA and avrA, growth and intracellular invasion and survival
- Source :
- Veterinary microbiology. 133(4)
- Publication Year :
- 2008
-
Abstract
- A variety of environmental factors, such as oxygen, pH, osmolarity and antimicrobial agents, modulate the expression of Salmonella pathogenicity islands (SPI) genes. This study investigated SPI-1 gene expression and the pathogenicity of quinolone-resistant Salmonella. mRNA expression levels of the invA and avrA genes, located in SPI-1, in quinolone-susceptible and quinolone-resistant Salmonella strains were determined using real-time fluorescent quantitative reverse transcription-polymerase chain reaction (RT-PCR). Twenty-five quinolone-resistant Salmonella mutants were derived from quinolone-susceptible strains by multiple-passage selection through increasing concentrations of ciprofloxacin in vitro, while an additional 15 strains were quinolone-resistant Salmonella clinical isolates. Sequence analysis showed no gene deletion or point mutations of nine SPI-1 genes (including invA and avrA) occurred in either the selected or clinical quinolone-resistant strains, while a single gyrA point mutation (S83F) was observed in all 40 quinolone-resistant strains. The mRNA expression levels of invA and avrA were significantly decreased (P
- Subjects :
- Salmonella
Mutant
Virulence
Down-Regulation
Microbial Sensitivity Tests
Biology
Quinolones
medicine.disease_cause
Microbiology
Mice
Bacterial Proteins
Drug Resistance, Multiple, Bacterial
Gene expression
medicine
Animals
Humans
RNA, Messenger
Gene
Regulation of gene expression
Antiinfective agent
General Veterinary
Macrophages
General Medicine
Gene Expression Regulation, Bacterial
Pathogenicity island
Molecular biology
Anti-Bacterial Agents
HeLa Cells
Subjects
Details
- ISSN :
- 03781135
- Volume :
- 133
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Veterinary microbiology
- Accession number :
- edsair.doi.dedup.....72db8f2290b5ea0d80de8ae360b1c6b2