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  • Adjunctive corticosteroid therapy improves lung immunopathology and survival during severe secondary pneumococcal pneumonia in mice.

Adjunctive corticosteroid therapy improves lung immunopathology and survival during severe secondary pneumococcal pneumonia in mice.

The Journal of infectious diseases (2013-11-26)
Hazem E Ghoneim, Jonathan A McCullers
ABSTRACT

Secondary bacterial pneumonia is a significant cause of morbidity and mortality during influenza, despite routine use of standard antibiotics. Antibiotic-induced immunopathology associated with bacterial cell wall lysis has been suggested to contribute to these poor outcomes. Using Streptococcus pneumoniae in a well-established murine model of secondary bacterial pneumonia (SBP) following influenza, we stratified disease severity based on pneumococcal load in the lungs via in vivo bioluminescence imaging. Ampicillin treatment cured mice with mild pneumonia but was ineffective against severely pneumonic mice, despite effective bacterial killing. Adjunctive dexamethasone therapy improved ampicillin-induced immunopathology and improved outcomes in mice with severe SBP. However, early dexamethasone therapy during primary influenza infection impaired lung adaptive immunity as manifest by increased viral titers, with an associated loss of its protective functions in SBP. These data support adjunctive clinical use of corticosteroids in severe cases of community-acquired pneumonia.

MATERIALS
Product Number
Brand
Product Description

Supelco
Ampicillin Trihydrate, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Ampicillin trihydrate, VETRANAL®, analytical standard
Ampicillin trihydrate, European Pharmacopoeia (EP) Reference Standard
Sigma-Aldrich
Ampicillin, meets USP testing specifications
Sigma-Aldrich
Ampicillin trihydrate, 900-1050 μg/mg anhydrous basis (HPLC)
Ampicillin, anhydrous, European Pharmacopoeia (EP) Reference Standard
Supelco
Ampicillin, analytical standard
Sigma-Aldrich
Ampicillin sodium salt, BioXtra, suitable for cell culture
Sigma-Aldrich
Ampicillin sodium salt
Sigma-Aldrich
Ampicillin, anhydrous, 96.0-102.0% (anhydrous basis)
Sigma-Aldrich
Ampicillin sodium salt, powder or crystals, BioReagent, suitable for cell culture
USP
Ampicillin, United States Pharmacopeia (USP) Reference Standard
Supelco
Ampicillin Sodium, Pharmaceutical Secondary Standard; Certified Reference Material