Revista chilena de pediatría
versión impresa ISSN 0370-4106
FRAGA, José Carlos et al. Experimental empyema in rats through intrapleural injection of bacteria. Rev. chil. pediatr. [online]. 2003, vol.74, n.5, pp. 526-533. ISSN 0370-4106. http://dx.doi.org/10.4067/S0370-41062003000500013.
Objective: to evaluate empyema formation in rats through the injection of two bacteria (Pasteurella multocida and Staphylococcus aureus), using a simple, easy-to-use surgical technique. Methods:twenty four anesthetized Wistar white rats, 250-300g in weight, submitted to right anterior thoracotomy, muscular retraction and injection of a 0.2 ml solution into pleural space according the following scheme: Group I (n = 12): injection of 10 10 Pasteurella multocidacultured in pain heart infusion poth. Group II (n = 8): injection of 10 10 Staphylococcus aureuscultured in pain heart infusion poth. Group III (n = 4): injection of bacterium-free pain heart infusion (control). The rats were sacrificed after seven days, and pleural reaction was assessed by macroscopy. Mortality, and intrathoracic liquid volume were evaluated, and bacteriological tests were also performed. Results: Seven rats died within the first 48 hours in Group I (Pasteurella multocida); five completed the experiment, but none of them presented empyema. Only one animal died within the first 24 hours in Group II (Staphylococcus aureus); seven (88%) presented empyema at the time of sacrifice. All animals survived in Group III (control), without empyema or thoracic abnormalities. Pleural inoculation of Staphylococcus aureus (Group II) was significantly associated with empyema formation (P < 0.001). In this group, the amount of pleural liquid ranged from 0.9 to 3.9 ml. Conclusion: It is possible to induce empyema in rats through Staphylococcus aureuspleural injection by a simple surgical technique. Differently from other experiments, the pleural injection of Pasteurella multocidadid not provoke empyema in rats
Palabras clave : pleural diseases; Staphylococcus aureus; Pasteurella multocida.