Does cold environment affect Streptococcus pneumoniae adherence to rat buccal epithelium?

Area of Science:

• Microbiology
• Immunology
• Environmental Health

Background:

• Nasopharyngeal colonization by Streptococcus pneumoniae (pneumococcus) rises in winter.
• In vitro data suggest reduced bacterial adherence at lower temperatures.
• A discrepancy exists between in vitro findings and in vivo observations regarding pneumococcal adherence in cold conditions.

Purpose of the Study:

• To investigate the effect of cold temperatures on pneumococcal adherence to rat buccal epithelial cells in vivo.
• To explore whether cold exposure influences bacterial colonization of the nasopharynx.

Main Methods:

• Six groups of rats were used to study Streptococcus pneumoniae (ATCC 49619) adherence.
• Adherence was assessed under various cold exposure conditions: during the whole study, post-inoculation, and pre-inoculation.
• Control groups were maintained at room temperature (24°C) or exposed to cold (10°C) for basal adherence evaluation.

Main Results:

• Pneumococcal adherence significantly decreased in rats exposed to cold (10°C) throughout the study period.
• Cold exposure after bacterial inoculation showed a non-significant decrease in adherence.
• Conversely, rats at room temperature (24°C) exhibited significantly increased pneumococcal adherence.

Conclusions:

• In vivo, cold environments reduce pneumococcal adherence to host cells, contradicting in vitro predictions.
• Environmental temperature plays a crucial role in regulating bacterial colonization dynamics.
• Findings suggest a complex interaction between temperature and host-pathogen interactions in vivo.