1. Typical pneumococci were present dunng the winter months in the throat secretions of a large percentage of healthy individuals in city and country. 2. A higher percentage of atypical strains of pneumococci have been obtained from healthy persons than from those suffering from pneumonia. In the latter cases the atypical strains may have been overlooked, because of the larger number of typical...

The characteristic appearances exhibited by the surface colonies of both S and R pneumococci in 24 and 48 hour cultures upon rabbit blood agar have been reviewed. Emphasis has been laid upon the behavior and structure of the colonies formed by R pneumococci, their frequent similarity to the colonies formed by certain strains of Streptococcus viridans, and their failure to undergo rapid autolysi...

The role of nitric oxide (NO) in the pathophysiology of gram-positive sepsis is uncertain. In inflammatory conditions, high-output NO production is catalyzed by the enzyme inducible nitric oxide synthase (iNOS). The ability of 2 strains of pneumococci, pneumococcal cell wall preparations, and purified pneumococcal capsule (Pnu-Imune 23) to trigger the production of iNOS protein and NO in RAW 26...

Pediatric parapneumonic empyema (PPE) has been increasing in several countries including Spain. Streptococcus pneumoniae is a major PPE pathogen; however, antimicrobial pretreatment before pleural fluid (PF) sampling frequently results in negative diagnostic cultures, thus greatly underestimating the contribution of pneumococci, especially pneumococci susceptible to antimicrobial agents, to PPE...

Pulmonary edema is a component of the fully developed influenza viral lesion in the mouse. Mice with experimental pulmonary fluid have an increased susceptibility to inhaled pneumococci and under these circumstances the organisms grow in the lung and produce the lesion of bacterial pneumonia. The presence of pulmonary edema in the lesion due to the influenza virus in the lung of the mouse appea...

Streptococcus pneumoniae is thought to adhere to the blood-brain barrier (BBB) endothelium prior to causing meningitis. The platelet activating factor receptor (PAFR) has been implicated in this adhesion but there is a paucity of data demonstrating direct binding of the bacteria to PAFR. Additionally, studies that inhibit PAFR strongly suggest that alternative receptors for pneumococci are pres...

The capsular polysaccharide of Streptococcus pneumoniae represents an important virulence factor and protects against phagocytosis. In this study the amount of capsular polysaccharide present on the bacterial surface during the infection process was illustrated by electron microscopic studies. After infection of A549 cells (type II pneumocytes) and HEp-2 epithelial cells a modified fixation met...

Most Streptococcus pneumoniae strains are killed by very low concentrations of penicillin and other beta-lactam antibiotics, yet middle ear inflammation and effusion persist for days to weeks after treatment in most cases of pneumococcal otitis media. To study the effect of beta-lactam antibiotic treatment on pneumococci and the middle ear inflammatory response during pneumococcal otitis media,...