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Updated: Aug 3, 2026
A Non-invasive and Technically Non-intensive Method for Induction and Phenotyping of Experimental Bacterial Pneumonia in Mice
Published on: September 28, 2016
Pulmonary microbial infection in mice: comparison of different application methods and correlation of bacterial
A Munder1, S Krusch, T Tschernig
1Institute for Laboratory Animal, Medical School of Hannover, Germany. munder.antje@mh-hannover.de
Abstract:
Many investigations have been performed in characterising experimental bacterial infections in the lung of mice using several pathogens. Robust experimental pulmonary infection models require a reproducible method of application with defined numbers of pathogens to the respiratory tract without contaminating extrapulmonary tissues. At the same time trauma due to the experimental procedure should be kept to a minimum. So far several routes of administration have been used but a systematic comparison of these methods is still missing. Here we provide a comprehensive evaluation of view controlled i.t. instillation, tracheotomy, intranasal application, blind instillation and aerosol infection. An infection dose of up to 5 x 10(4) bacteria (L. monocytogenes) was applied to a group of ten mice by each technique and the animals were killed after 1 h or 24h. The number of viable bacteria was estimated by plating homogenates of the lungs and spleens. In addition, pathological effects on lung tissue were examined by histology 24h after infection. The highest reproducibility was achieved after applying Listeria directly in the trachea under view or by tracheotomy. However, mice were severely affected in their vitality after tracheotomy. Thus, for topical application of bacterial suspension into the lung the view controlled i.t. instillation is most appropriate.
Insights
For reproducible mouse lung infection models, view-controlled intratracheal instillation is superior. This method minimizes trauma and ensures accurate pathogen delivery, outperforming other techniques like tracheotomy or intranasal application.
Area of Science:
- * Microbiology
- * Immunology
- * Veterinary Medicine
Background:
- * Experimental bacterial lung infections in mice are crucial for research.
- * Existing methods for pathogen delivery lack systematic comparison and standardization.
- * Minimizing procedural trauma and ensuring accurate, reproducible pathogen delivery are key challenges.
Purpose of the Study:
- * To comprehensively evaluate and compare different methods for experimental bacterial lung infection in mice.
- * To identify the most reproducible and least invasive route for pathogen administration.
- * To guide the selection of optimal techniques for pulmonary infection models.
Main Methods:
- * Comparison of five administration routes: view-controlled intratracheal (i.t.) instillation, tracheotomy, intranasal application, blind instillation, and aerosol infection.
- * Application of a defined dose (up to 5 x 10^4 Listeria monocytogenes) to groups of ten mice.
- * Assessment of bacterial load in lungs and spleens at 1h and 24h post-infection.
- * Histological examination of lung tissue pathology 24h after infection.
Main Results:
- * View-controlled i.t. instillation and tracheotomy offered the highest reproducibility in pathogen delivery.
- * Tracheotomy significantly compromised animal vitality.
- * View-controlled i.t. instillation demonstrated the best balance of reproducibility and minimal invasiveness for topical lung application.
Conclusions:
- * View-controlled intratracheal instillation is the most appropriate method for reproducible topical application of bacterial suspensions into the mouse lung.
- * This technique enhances the reliability of pulmonary infection models.
- * Careful selection of administration routes is critical for robust experimental outcomes.
