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Autoinducer 2–Like Activity in Poultry-Associated Enteric Bacteria in Response to Subtherapeutic Antibiotic Exposure
- Source :
- Avian Diseases. 49:74-80
- Publication Year :
- 2005
- Publisher :
- American Association of Avian Pathologists (AAAP), 2005.
-
Abstract
- The autoinducer-2 molecule, AI-2, is considered to be a universal signal for regulating a wide variety of physiological processes in bacteria by modulating gene expression. Studies were conducted to observe how Escherichia coli cells would respond to subtherapeutic tetracycline concentrations under continuous culture (chemostat) conditions, to observe AI-2 activity within the probiotic chicken microbial consortium (Preempt CF3; MS Bioscience, Dundee, IL) under in vitro conditions simulating a chicken cecum, and to observe the AI-2 activity in vivo within a chicken cecum as a function of exposure to subtherapeutic levels of chlortetracydine, tylosin, and vancomycin. The AI-2 activity in the E. coli continuous culture showed a 20-fold increase over baseline conditions for up to 24 hours. When the E. coli culture was subsequently exposed to pulses of chlortetracydine additions at subtherapeutic concentrations (2 microg/ml), AI-2 activity increased with increasing levels of tetracycline additions. The probiotic Preempt CF3 culture, however, did not exhibit any AI-2 activity in Viande Levure (VL) medium in the presence or absence of subtherapeutic levels of tetracycline. In vivo studies in the cecum of poultry chicks demonstrate that though AI-2 activity increased initially in the presence of vancomycin, there was no significant increase in AI-2 activity in the presence of tetracydine or tylosin. These results indicate that detectable levels of AI-2 activity are not evident within the probiotic culture (CF3) or within the chicken cecum. Understanding the relationships between AI-2 activity and microbial consortia characteristics could provide dues regarding the vulnerability of poultry chicks to enteric bacterial pathogen colonization.
- Subjects :
- Chlortetracycline
Tetracycline
Cell Count
Tylosin
Biology
medicine.disease_cause
Microbiology
law.invention
Lactones
Cecum
chemistry.chemical_compound
Probiotic
Food Animals
Vancomycin
law
Escherichia coli
Homoserine
medicine
Animals
General Immunology and Microbiology
Probiotics
biology.organism_classification
Anti-Bacterial Agents
Culture Media
Autoinducer-2
medicine.anatomical_structure
chemistry
Animal Science and Zoology
Chickens
Bacteria
medicine.drug
Subjects
Details
- ISSN :
- 19384351 and 00052086
- Volume :
- 49
- Database :
- OpenAIRE
- Journal :
- Avian Diseases
- Accession number :
- edsair.doi.dedup.....746a665caeba22417f09ade0d4289956