In Escherichia coli , the bifunctional penicillin-binding proteins (PBPs), PBP1A and PBP1B, play critical roles in the final stage of peptidoglycan (PG) biosynthesis. These synthetic enzymes each possess a PG glycosyltransferase (PGT) domain and a transpeptidase (TP) domain. Recent genetic experiments have shown that PBP1A and PBP1B each require an outer membrane lipoprotein, LpoA and LpoB, res...

Streptococcus pneumoniae CS109 and CS111 were isolated in the United States in 1991 and have high levels of resistance to expanded-spectrum cephalosporins (MICs of 8 and 32 micrograms of cefotaxime per ml, respectively). CS109, but not CS111, also showed high-level resistance to penicillin. As both strains expressed the serotype 23F capsule, were very closely related in overall genotype, and po...

coding regions of the transpeptidase domain of the pbp1a, pbp2b and pbp2x genes of the two GBS isolates were amplified and sequenced according to previously outlined methods. 4 Amino acid sequences were deduced and analysed using the ClustalW alignment tool included in the Lasergene software (DNAstar, Madison, WI, USA). Nucleotide and deduced amino acid sequences were compared with those of the...

Evasion of host immune defenses is critical for the progression of invasive infections caused by the leading neonatal pathogen, group B streptococcus (GBS). Upon characterizing the factors required for virulence in a neonatal rat sepsis model, we found that a surface-associated penicillin-binding protein (PBP1a), encoded by ponA, played an essential role in resistance of GBS to phagocytic clear...

European serotype 14 variants of the France 9V(-3) clone, which have arisen through recombination events involving the penicillin binding protein 1a (pbp1a) gene, have cpsB sequences distinct from those of the 9V(-3) clone. Serotype 14 variants of the 9V(-3) clone have not been compared to genetically diverse serotype 14 strains isolated from an entire metropolitan area in the United States. Al...

The peptidoglycan cell wall is an integral organelle critical for bacterial cell shape and stability. Proper cell wall construction requires the interaction of synthesis enzymes and the cytoskeleton, but it is unclear how the activities of individual proteins are coordinated to preserve the morphology and integrity of the cell wall during growth. To elucidate this coordination, we used single-m...

After the introduction of pneumococcal conjugate vaccines, the incidence of pneumococcal infections due to meropenem-resistant serotype 15A-ST63 strains increased in Japan. By using whole-genome sequencing and comparing sequences with those of clones from the United Kingdom, the United States, and Canada, we clarified the traits of the serotype 15A-ST63 clone. Our analysis revealed that the mer...

The main mechanism of resistance of pneumococci to penicillin is the alteration of the affinities of penicillin binding proteins (PBPs) to -lactams by heterologous recombination events (4). For the present study, we have investigated the diversity of the penA (accession numbers AM779386 to AM779409), pbpX (AM779338 to AM779361), and pbp1A (AM779362 to AM779385) genes of 21 clinical Portuguese S...

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...

results the number of s. pneumoniae isolates resistant to benzylpenicillin, imipenem, oxacillin and ceftazidime were 94.5%, 100%, 100%, and 21.8%, respectively. analysis of mutation in the genes for pbp showed that 85% of isolates had mutations in pbp2x, pbp2b and pbp1a. susceptibility to benzylpenicillin was decreased once the number of mutated pbp genes in s. pneumonia increased. according to...