Hemorrhage Attenuates Neutrophil Recruitment in Response to Secondary Respiratory Infection by Pseudomonas Aeruginosa.
Shock
; 52(5): 506-512, 2019 11.
Article
en En
| MEDLINE
| ID: mdl-30475329
ABSTRACT
Neutrophil recruitment into the lung airspaces plays an important role in the containment and clearance of bacteria. Hemorrhagic shock, a complication of traumatic injury, induces immune dysfunction that compromises host defense and frequently leads to secondary infection. The objective of the current study was to determine whether prior hemorrhage impacts neutrophil recruitment in response to secondary Pseudomonas aeruginosa. Experiments were performed using a mouse model (C57BL/6) of respiratory infection by P. aeruginosa (strain PA103, 3â×â10 colony-forming units [CFUs]) that is delivered by intratracheal inhalation 24âh after hypovolemic hemorrhagic shock (fixed mean arterial blood pressure at 35âmmHg for 90âmin, Ringer's lactate infused as fluid resuscitation). By postmortem flow cytometry analyses of bronchoalveolar lavage fluid, we observe that prior hemorrhage attenuates the entry of neutrophils into the lung airspaces in response to P. aeruginosa. The reduction in neutrophil recruitment occurs in an amplified inflammatory environment, with elevated lung tissue levels of interleukin 6 and C-X-C motif ligand 1 in mice receiving hemorrhage prior to infection. As compared to either insult alone, outcome to sequential hemorrhage and respiratory infection includes enhanced mortality. The effect of prior hemorrhage on clearance of P. aeruginosa, as determined by quantifying bacterial CFUs in lung tissue, was not statistically significant at 24âh postinfection, but our data suggest that further inquiry may be needed to fully understand the potential impact of hemorrhagic shock on this process. These results suggest that changes in neutrophil recruitment may contribute to the immune dysfunction following hemorrhagic shock that renders the host susceptible to severe respiratory infection.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Pseudomonas aeruginosa
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Infecciones por Pseudomonas
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Infecciones del Sistema Respiratorio
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Hemorragia
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Neutrófilos
Tipo de estudio:
Etiology_studies
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Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
2019
Tipo del documento:
Article