psaA encodes a 37-kDa pneumococcal lipoprotein which is part of an ABC Mn(II) transport complex. Streptococcus pneumoniae D39 psaA mutants have previously been shown to be significantly less virulent than wild-type D39, but the mechanism underlying the attenuation has not been resolved. In this study, we have shown that psaA and psaD mutants are highly sensitive to oxidative stress, i.e., to su...

UNLABELLED We determined whether there is turnover of the peptidoglycan (PG) cell wall of the ovococcus bacterial pathogen Streptococcus pneumoniae (pneumococcus). Pulse-chase experiments on serotype 2 strain D39 radiolabeled with N-acetylglucosamine revealed little turnover and release of PG breakdown products during growth compared to published reports of PG turnover in Bacillus subtilis. PG ...

Streptococcus pneumoniae is the world's leading cause of pneumonia, bacteremia, meningitis and otitis media. A major pneumococcal virulence factor is the cholesterol-dependent cytolysin, which has the defining property of forming pores in cholesterol-containing membranes. In recent times a clinically significant and internationally successful serotype 1 ST306 clone has been found to express a n...

Streptococcus pneumoniae is one of the most frequent opportunistic pathogens worldwide. DNA processing protein A (DprA) is an important factor involved in bacterial uptake and DNA integration into bacterial genome, but its role in S. pneumoniae virulence remains unclear. The aim of this study was to characterize the effects of the pneumococcal dprA gene on the pathogenesis of S. pneumoniae. To ...

MreC and MreD, along with the actin homologue MreB, are required to maintain the shape of rod-shaped bacteria. The depletion of MreCD in rod-shaped bacteria leads to the formation of spherical cells and the accumulation of suppressor mutations. Ovococcus bacteria, such as Streptococcus pneumoniae, lack MreB homologues, and the functions of the S. pneumoniae MreCD (MreCD(Spn)) proteins are unkno...

Aspirin or acetylsalicylic acid (ASA) is a medicine used to treat pain, fever, and inflammation. Here, we for the very first time reported the genome-wide transcriptional profiling of aspirin-regulated genes in Streptococcus pneumoniae in the presence of 5 mM aspirin in chemically-defined medium (CDM) using microarray analysis. Our results showed that expression of several genes was differentia...

There are a number of problems associated with current windowing environments, such as the lack of consistency both within and between applications, the poor integration between applications, little or no interoperability, ‘hard-wired’ and inflexible interfaces, and the enormous cost of producing applications. These problems are examined, and a unified approach that addresses them is presented....

This document discusses the ergonomic problems with currently available software products, and what in general is necessary in order to make an application pleasant to work with. The application of these principles to a new open-architecture user interface system, Views, is then described. 1991 Mathematics Subject Classification: 68U99. 1991 CR Categories: H.1.2, H.5.2, D39, H.5.0, I.7.2.