Related Experiment Videos
Subinhibitory concentrations of erythromycin reduce pneumococcal adherence to respiratory epithelial cells in vitro
K Lagrou1, W E Peetermans, M Jorissen
1Infectious Diseases Research Group, Departments of Microbiology and Immunology and Internal Medicine, Rega Institute for Medical Research, K. U. Leuven, Minderbroedersstraat 10, 3000 Leuven, Belgium. katrien.lagrou@rega.kuleven.ac.be
Abstract:
We have investigated the influence of subinhibitory concentrations of erythromycin on the interaction between Streptococcus pneumoniae and human respiratory epithelial cells. Confluent in vitro cell cultures were inoculated with erythromycin-resistant S. pneumoniae and incubated for 24 h. Erythromycin significantly reduced adherence of the pneumococci after 4 h and 24 h: 4.0% +/- 0.7% (mean +/- S.E.M. ) of the pneumococci adhered to the epithelial cells in medium with erythromycin, compared with 7.7% +/- 0.8% in medium without erythromycin (P: = 0.002) after 4 h, and the corresponding values after 24 h were 24.2% +/- 5.3% and 38.4% +/- 5.0%, respectively (P: = 0.038). Disruption of epithelial integrity by S. pneumoniae, measured as the decrease in transepithelial electrical resistance, was delayed in the presence of erythromycin. Neither addition of erythromycin to the culture medium nor infection of the cell cultures with pneumococci significantly affected secretion of interleukin-8 by the epithelial cells. Addition of erythromycin to a pneumococcal suspension in cell culture medium without respiratory epithelial cells almost completely prevented the release of pneumolysin. We conclude that erythromycin at subinhibitory concentrations reduces the adherence to and disruption of respiratory epithelial cells by S. pneumoniae, possibly by interfering with pneumolysin release.
Insights
Subinhibitory erythromycin concentrations significantly reduce Streptococcus pneumoniae adherence to respiratory cells. This antibiotic may also interfere with pneumolysin release, impacting bacterial virulence.
Area of Science:
- Microbiology
- Cell Biology
- Pharmacology
Background:
- Streptococcus pneumoniae is a major cause of respiratory infections.
- Understanding how subinhibitory antibiotic concentrations affect bacterial-host interactions is crucial for treatment strategies.
Purpose of the Study:
- To investigate the impact of subinhibitory erythromycin concentrations on the interaction between S. pneumoniae and human respiratory epithelial cells.
- To determine if erythromycin affects bacterial adherence, epithelial integrity, or inflammatory responses.
Main Methods:
- In vitro culture of human respiratory epithelial cells.
- Inoculation with erythromycin-resistant S. pneumoniae.
- Measurement of bacterial adherence, transepithelial electrical resistance, and interleukin-8 secretion.
- Assessment of pneumolysin release.
Main Results:
- Erythromycin significantly reduced S. pneumoniae adherence at 4 and 24 hours (P < 0.05).
- Erythromycin delayed the disruption of epithelial integrity caused by S. pneumoniae.
- Interleukin-8 secretion was not significantly affected by erythromycin or pneumococcal infection.
- Erythromycin almost completely prevented pneumolysin release from S. pneumoniae.
Conclusions:
- Subinhibitory erythromycin concentrations decrease S. pneumoniae adherence to respiratory epithelial cells.
- Erythromycin may reduce bacterial virulence by inhibiting pneumolysin release.
- These findings suggest a potential role for subinhibitory erythromycin in managing pneumococcal respiratory infections.