bTo better understand the role of Opa in gonococcal infections, we created and characterized a derivative of MS11 (MS11⌬opa) that had the coding sequence for all 11 Opa proteins deleted. The MS11⌬opa bacterium lost the ability to bind to purified lipooligosaccharide (LOS). While nonpiliated MS11⌬opa and nonpiliated Opa-expressing MS11 cells grew at the same rate, nonpiliated MS11⌬opa cells rarely formed clumps of more than four bacteria when grown in broth with vigorous shaking. Using flow cytometry analysis, we demonstrated that MS11⌬opa produced a homogeneous population of bacteria that failed to bind monoclonal antibody (MAb) 4B12, a MAb specific for Opa. Opa-expressing MS11 cells consisted of two predominant populations, where ϳ85% bound MAb 4B12 to a significant level and the other population bound little if any MAb. Approximately 90% of bacteria isolated from a phenotypically Opa-negative colony (a colony that does not refract light) failed to bind MAb 4B12; the remaining 10% bound MAb to various degrees. Piliated MS11⌬opa cells formed dispersed microcolonies on ME180 cells which were visually distinct from those of piliated Opa-expressing MS11 cells. When Opa expression was reintroduced into MS11⌬opa, the adherence ability of the strain recovered to wild-type levels. These data indicate that Opa contributes to both bacterium-bacterium and bacterium-host cell interactions.

Fluorescent silica nanoparticles (FSNs) are prepared by incorporating dye into a mesoporous silica nanoparticle (MSN) synthesis procedure. FSNs containing sulforhodamine B, hydrophobically modified sulforhodamine B, and Cascade Blue hydrazide are made. The MSN‐based FSNs do not leach dye under simulated physiological conditions and have strong, stable fluorescence. FSNs prepared with sulforhodamine B are compared to FSNs prepared with hydrophobically modified sulforhodamine B. The data indicate that FSNs prepared with sulforhodamine B are equally as stable but twice as fluorescent as particles made with hydrophobically modified sulforhodamine B. The fluorescence of a FSN prepared with sulforhodamine B is 10 times more intense than the fluorescence of a 4.5 nm core–shell CdSe/ZnS quantum dot. For diagnostic applications, a method to selectively and covalently bind antibodies to the surface of the FSNs is devised. FSNs that are functionalized with antibodies specific for Neisseria gonorrhoeae specifically bind to Neisseria gonorrhoeae in flow cytometry experiments, thus demonstrating the functionality of the attached antibodies and the potential of MSN‐based FSNs to be used in diagnostic applications.

Glycomics lags substantially behind proteomics and genomics in its ability to decipher and synthesize complex glycans. The slow progress in deciphering glycan interactions at a molecular level is in large part due to the absence of a functional system to express, on a large scale, carbohydrates of known structure, in the context of a biologically relevant assay system. Here we describe the characterization of a glycan-functionalized catanionic surfactant vesicles (CVs) as a platform for glycan synthesis, and to demonstrate that the resulting glycan-functionalized CVs can serve as a scaffold for the interrogation of protein-glycan interactions. We demonstrate that N. gonorrhoeae lipooligosaccharide (LOS) glycosyltransferase LgtE, an enzyme that catalyzes the addition of galactose onto a terminal glucose found on LOS can be used to biochemically modify LOS or glucose functionalized CVs. CVs were characterized by differential lectin binding using flow cytometry. LgtE activity was measured on whole cells and LOS functionalized vesicles and found to have approximately the same biochemical properties. We further demonstrate that CVs can be ink-jet printed. This paper presents proof-of-concept that glycan-functionalized catanionic vesicles can be used to create a high-specificity and high-throughput glycan array that will allow for the investigation of a variety of protein-glycan interactions.

Progressive familial intrahepatic cholestasis (PFIC) is a rare disease of impaired bile acid excretion which can lead to nutritional deficiencies. Vitamin deficiencies during pregnancy can result in adverse maternal and fetal outcomes. A 20-year-old primiparous woman at 30 4/7 weeks with PFIC type 2 presented with worsening cholestasis, coagulopathy and fat-soluble vitamin deficiency. She developed visual deficits and was found to have severe vitamin A deficiency. Her coagulopathy and visual deficits improved following vitamin K and A supplementation, respectively. She delivered at 32 2/7 weeks following preterm labour. This case highlights several unique aspects in the care of pregnant women with liver disease. These patients are at risk for fat-soluble vitamin deficiencies which can result in significant coagulopathy and rarely, visual deficits due to vitamin A deficiency. Prompt treatment is necessary to prevent permanent sequelae.