Group B streptococci (GBS) are a leading cause of neonatal sepsis and meningitis. GBS adhere to fibronectin when it is attached to a solid phase. We isolated a Tn917 transposon mutant, COH1-GT1, which shows decreased adherence to fibronectin. COH1-GT1 also shows decreased adherence to and invasion of respiratory epithelial cells in vitro and decreased virulence in vivo. COH1-GT1 contains a Tn91...

The rostral cluster of SCP-immunoreactive cells, originally identified in each buccal hemiganglion of juvenile Aplysia, was examined in mature specimens. Immunohistochemical and dye-fill experiments showed that each rostral cluster consists of approximately 40 cells. Although these neurons exhibit heterogeneity of size and shape, all cells project an axon into the radula nerve. Tracing of dye-f...

The plasticity of a synapse in the molluscan peripheral nervous system was examined under a variety of experimental, physiological, and pharmacological conditions. These studies employed the isolated salivary glands and attached buccal ganglia of the freshwater snail Helisoma. Action potentials evoked in buccal neuron 4 normally evoke a large excitatory postsynaptic potential (EPSP) which drive...

Intrinsic buccal muscle 5 (I5) in Aplysia is innervated by 2 motor neurons (termed B15 and B16). In addition to the classical transmitter ACh, B15 also contains the 2 neuropeptides SCPA and SCPB. In a previous study, we demonstrated that the SCPs were released from the terminals of B15 in the I5 muscle and that this release was sufficient to raise cAMP levels in I5 muscle fibers. Significant pe...

The adhesion of gram-positive bacteria to extracellular matrix (ECM) proteins is regarded as an important determinant of pathogenicity. A comparison of the adhesion of Streptococcus agalactiae strain O90R to different ECM proteins showed that the most pronounced binding could be observed for immobilized fibrinogen. To investigate the genetic determinants of S. agalactiae fibrinogen binding, a p...