The following is an observation on the survival of dry cultures of pneumococci and streptococci for seven years under unusual and adverse conditions of storage. Dry cultures of 27 pneumococci and 10 streptococci prepared by the Division of Laboratories and Research of the Department of Health of New York (Wadsworth, 1939) were given to the author on 17th July, 1940. All the cultures were examin...

1. Actively growing pneumococci produce acid at such a rate that change in the pH of the medium parallels change in rate of growth. 2. The death of the pneumococci is not followed by change in the reaction. 3. Acidification during growth in beef infusion media proceeds until a pH of about 7 is reached. At this point growth stops. The increase in hydrogen ion concentration is not the only origin...

Polymorphonuclear leucocytes contain an enzyme which destroys the basophilic character of beat-killed pneumococci (R and S variants) and inactivates the type specific polysaccharide antigen of encapsulated cells. The same enzyme, however, fails to cause a disintegration of the bacterial cells, or to decompose the capsular polysaccharide itself. The enzyme has been extracted from a number of ani...

Three multiresistant serotype 6B Streptococcus pneumoniae strains were isolated from the middle ear fluids of children undergoing tympanostomy in Atlanta. Because multiresistant 6B pneumococci have been reported to spread from a single clone, the three isolates were compared with 13 other multiresistant 6B pneumococci by hybridization of endonuclease-restricted DNA fragments with a digoxigenin-...

Adherence molecules are key players in pathogen-host interactions. These are usually surface-exposed structures that facilitate adherence to host cells, or target host serum proteins of the extracellular matrix. Our knowledge of the function of pneumococcal cell-surface structures, and the basic mechanisms underlying their interaction with host receptor molecules has dramatically increased, thr...

1. Living pneumococcus cells contain a group of enzymes, the bacteriolytic system, capable of causing the lysis of heat-killed pneumococci (R and S variants irrespective of type derivation). This lysis expresses itself by a loss of the Gram staining reaction, a disintegration of the cell body, and a clearing of the bacterial suspension. 2. Under certain conditions of treatment with the bacterio...

To the Editor: Streptococcus pneumoniae is a major human pathogen. In 2007, Park et al. identifi ed a novel serotype, 6C (1), which emerged from serotype 6A. A study of children in the Netherlands who had not previously received a pneumococcal vaccine found low prevalence of this newly identifi ed serotype before the heptavalent pneumococcal conjugate vaccine Prevnar/Prevenar (PCV7) (Wyeth, Tap...

Heat-labile opsonins to pneumococci in normal mammalian sera, unlike antibodies, fail to interact with the bacteria at 0 degrees C and require Ca(++) and/or Mg(++). They are readily removed from serum by antigen-antibody complexes that fix complement (C) and are inhibited by reagents that inactivate various C components. The principal heat-labile opsonin to pneumococci is activated C3 (C3(b)), ...

In the preceding paper (1) are recorded the facts so far obtained in a study of the proteolytic enzymes of pneumococcus. It has been shown that bile solutions of pneumococci, extracts obtained by disintegration of the organisms in phosphate mixtures, and sterile filtrates of autolyzing broth cultures possess the power to hydrolyze peptones and to a less extent certain intact proteins. In the pr...

1. When mice are exposed to an atmosphere containing cultures of bacteria in the form of a fine mist, the bacteria readily penetrate into the lower respiratory tract. 2. Pneumococci which have reached the lung as a result of this procedure usually disappear within a few hours and give rise to no infection. Hemolytic streptococci, on the other hand, persist in the lung for a considerably longer ...