Different Classes of Antibiotics Differentially Influence Shiga Toxin Production
| Autor: | Colleen M. McGannon, Cynthia Ann Fuller, Alison A. Weiss |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Sulfamethoxazole
Azithromycin Escherichia coli O157 medicine.disease_cause Trimethoprim Shiga Toxin Microbiology Bacteriophage chemistry.chemical_compound Shiga-like toxin Lysogen Ciprofloxacin hemic and lymphatic diseases Lysogenic cycle Escherichia coli medicine Bacteriophages Pharmacology (medical) Mechanisms of Action: Physiological Effects Antibacterial agent Pharmacology biology Shiga toxin biology.organism_classification Anti-Bacterial Agents Infectious Diseases Lytic cycle chemistry biology.protein |
| Zdroj: | Antimicrobial Agents and Chemotherapy. 54:3790-3798 |
| ISSN: | 1098-6596 0066-4804 |
| Popis: | Shiga toxin (Stx) in Escherichia coli O157:H7 is encoded as a late gene product by temperate bacteriophage integrated into the chromosome. Phage late genes, including stx , are silent in the lysogenic state. However, stress signals, including some induced by antibiotics, trigger the phage to enter the lytic cycle, and phage replication and Stx production occur concurrently. In addition to the Stx produced by O157:H7, phage produced by O157:H7 can infect harmless intestinal E. coli and recruit them to produce Shiga toxin. To understand how antibiotics influence Stx production, Stx lysogens were treated with different classes of antibiotics in the presence or absence of phage-sensitive E. coli , and Stx-mediated inhibition of protein synthesis was monitored using luciferase-expressing Vero cells. Growth-inhibitory levels of antibiotics suppressed Stx production. Subinhibitory levels of antibiotics that target DNA synthesis, including ciprofloxacin (CIP) and trimethoprim-sulfamethoxazole, increased Stx production, while antibiotics that target the cell wall, transcription, or translation did not. More Stx was produced when E. coli O157:H7 was incubated in the presence of phage-sensitive E. coli than when grown as a pure culture. Remarkably, very high levels of Stx were detected even when growth of O157:H7 was completely suppressed by CIP. In contrast, azithromycin significantly reduced Stx levels even when O157:H7 viability remained high. |
| Databáze: | OpenAIRE |
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