Drug discovery in the new millennium: the pivotal role of biotechnology.

Biotechnology has made, and will continue to make, a major contribution to the health of mankind by providing new insights into disease and acting as a pivotal enabler for the drug-discovery process. The available techniques are diverse and changing rapidly: selecting and integrating the best approach is the key to success.

Streptococcus pneumoniae produces a second haemolysin that is distinct from pneumolysin.

Pneumococci are described as alpha-haemolytic but under certain circumstances they produce zones of beta-haemolysis on blood-containing medium. This observation was investigated using wild type strains and a genetically-modified strain unable to produce the haemolytic toxin, pneumolysin. beta-haemolysis was produced by all pneumococci tested.

Region 2 of the Escherichia coli K5 capsule gene cluster encoding proteins for the biosynthesis of the K5 polysaccharide.

The nucleotide sequence of region 2 of the Escherichia coli K5 capsule gene cluster has been determined. This region, essential for the biosynthesis of the K5 polysaccharide, contained four genes, termed kfiA-D. The G + C ratio was 33.

The role of pneumolysin and autolysin in the pathology of pneumonia and septicemia in mice infected with a type 2 pneumococcus.

Mice were infected intranasally with a serotype 2 pneumococcus, a pneumolysin-negative derivative (PLN-A), or an autolysin-negative derivative (AL-2). Numbers of wild type pneumococci were seen in the lung from approximately 12 h after infection and were first detected in the blood around this time. Immunofluorescent staining of lung sections showed that pneumolysin was produced in vivo.

Growth and virulence of a complement-activation-negative mutant of Streptococcus pneumoniae in the rabbit cornea.

Our previous work has demonstrated the importance of pneumolysin in the virulence of S. pneumoniae in a rabbit intracorneal model. This was accomplished by showing that deletion of the gene encoding pneumolysin resulted in reduced virulence, whereas restoration of the wild-type gene resulted in restoration of the virulent phenotype.