학술논문
Development and characterization of a new swine model of invasive pneumococcal pneumonia
Document Type
Report
Author
Source
Lab Animal. November 2021, Vol. 50 Issue 11, p327, 9 p.
Subject
Language
English
ISSN
0093-7355
Abstract
Author(s): Rosanel Amaro [sup.1] [sup.2] [sup.3] , Gianluigi Li Bassi [sup.1] [sup.2] [sup.4] [sup.5] , Ana Motos [sup.1] [sup.2] [sup.3] [sup.6] , Laia Fernandez-Barat [sup.1] [sup.2] [sup.3] [sup.6] , Eli [...]
Streptococcus pneumoniae is the most common microbial cause of community-acquired pneumonia. Currently, there are no available models of severe pneumococcal pneumonia in mechanically ventilated animals to mimic clinical conditions of critically ill patients. We studied endogenous pulmonary flora in 4 healthy pigs and in an additional 10 pigs in which we intra-bronchially instilled S. pneumoniae serotype 19 A, characterized by its resistance to penicillin, macrolides and tetracyclines. The pigs underwent ventilation for 72 h. All pigs that were not challenged with S. pneumoniae completed the 72-h study, whereas 30% of infected pigs did not. At 24 h, we clinically confirmed pneumonia in the infected pigs; upon necropsy, we sampled lung tissue for microbiological/histological confirmation of pneumococcal pneumonia. In control pigs, Streptococcus suis and Staphylococcus aureus were the most commonly encountered pathogens, and their lung tissue mean [plus or minus] s.e.m. concentration was 7.94 [plus or minus] 20 c.f.u./g. In infected pigs, S. pneumoniae was found in the lungs of all pigs (mean [plus or minus] s.e.m. pulmonary concentration of 1.26 × 10.sup.5 [plus or minus] 2 × 10.sup.2 c.f.u./g). Bacteremia was found in 50% of infected pigs. Pneumococcal pneumonia was confirmed in all infected pigs at 24 h. Pneumonia was associated with thrombocytopenia, an increase in prothrombin time, cardiac output and vasopressor dependency index and a decrease in systemic vascular resistance. Upon necropsy, microbiological/histological pneumococcal pneumonia was confirmed in 8 of 10 pigs. We have therefore developed a novel model of penicillin- and macrolide-resistant pneumococcal pneumonia in mechanically ventilated pigs with bacteremia and severe hemodynamic compromise. The model could prove valuable for appraising the pathogenesis of pneumococcal pneumonia, the effects associated with macrolide resistance and the outcomes related to the use of new diagnostic strategies and antibiotic or complementary therapies. In this article, the authors characterize a new swine model of invasive pneumococcal pneumonia in mechanically ventilated pigs to mimic clinical conditions of critically ill patients.
Streptococcus pneumoniae is the most common microbial cause of community-acquired pneumonia. Currently, there are no available models of severe pneumococcal pneumonia in mechanically ventilated animals to mimic clinical conditions of critically ill patients. We studied endogenous pulmonary flora in 4 healthy pigs and in an additional 10 pigs in which we intra-bronchially instilled S. pneumoniae serotype 19 A, characterized by its resistance to penicillin, macrolides and tetracyclines. The pigs underwent ventilation for 72 h. All pigs that were not challenged with S. pneumoniae completed the 72-h study, whereas 30% of infected pigs did not. At 24 h, we clinically confirmed pneumonia in the infected pigs; upon necropsy, we sampled lung tissue for microbiological/histological confirmation of pneumococcal pneumonia. In control pigs, Streptococcus suis and Staphylococcus aureus were the most commonly encountered pathogens, and their lung tissue mean [plus or minus] s.e.m. concentration was 7.94 [plus or minus] 20 c.f.u./g. In infected pigs, S. pneumoniae was found in the lungs of all pigs (mean [plus or minus] s.e.m. pulmonary concentration of 1.26 × 10.sup.5 [plus or minus] 2 × 10.sup.2 c.f.u./g). Bacteremia was found in 50% of infected pigs. Pneumococcal pneumonia was confirmed in all infected pigs at 24 h. Pneumonia was associated with thrombocytopenia, an increase in prothrombin time, cardiac output and vasopressor dependency index and a decrease in systemic vascular resistance. Upon necropsy, microbiological/histological pneumococcal pneumonia was confirmed in 8 of 10 pigs. We have therefore developed a novel model of penicillin- and macrolide-resistant pneumococcal pneumonia in mechanically ventilated pigs with bacteremia and severe hemodynamic compromise. The model could prove valuable for appraising the pathogenesis of pneumococcal pneumonia, the effects associated with macrolide resistance and the outcomes related to the use of new diagnostic strategies and antibiotic or complementary therapies. In this article, the authors characterize a new swine model of invasive pneumococcal pneumonia in mechanically ventilated pigs to mimic clinical conditions of critically ill patients.