Citation Details

Journal Article

Xen5, Xen 5, Pseudomonas aeruginosa

The ability of brominated furanones and other furanone compounds with 2(3H) and 2(5H) cores to inhibit bacterial adhesion of surfaces as well deactivate (destroy) them has been previously reported. The furanone derivatives 4-(2-(2-aminoethoxy)-2,5-dimethyl-3(2H)-furanone and 5-(2-(2-aminoethoxy)-ethoxy)methyl)-2(5H)-furanone were synthesized in our laboratory. These furanone derivatives were then covalently immobilized onto poly(styrene-co-maleic anhydride) (SMA) and electrospun to fabricate nonwoven nanofibrous mats with antimicrobial and cell-adhesion inhibition properties. The electrospun nanofibrous mats were tested for their ability to inhibit cell attachment by strains of bacteria commonly found in water ( Klebsiella pneumoniae Xen 39, Staphylococcus aureus Xen 36, Escherichia coli Xen 14, Pseudomonas aeruginosa Xen 5, and Salmonella tymphimurium Xen 26). Proton nuclear magnetic resonance spectroscopy ((1)H NMR), electrospray mass spectroscopy (ES-MS), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used to confirm the structures of the synthesized furanones as well as their successful immobilization on SMA. To ascertain that the immobilized furanone compounds do not leach into filtered water, samples of water, filtered through the nanofibrous mats were analyzed using gas chromatography coupled with mass spectroscopy (GC-MS). The morphology of the electrospun nanofibers was characterized using scanning electron microscopy (SEM).

Journal Article

Xen31, Xen 31, MRSA, S. aureus, IVIS, Bioluminescence

Biofilms that develop on indwelling devices are a major concern in clinical settings. While removal of colonized devices remains the most frequent strategy for avoiding device-related complications, antibiotic lock therapy constitutes an adjunct therapy for catheter-related infection. However, currently used antibiotic lock solutions are not fully effective against biofilms, thus warranting a search for new antibiotic locks. Metal-binding chelators have emerged as potential adjuvants due to their dual anticoagulant/antibiofilm activities, but studies investigating their efficiency were mainly in vitro or else focused on their effects in prevention of infection. To assess the ability of such chelators to eradicate mature biofilms, we used an in vivo model of a totally implantable venous access port inserted in rats and colonized by either Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, or Pseudomonas aeruginosa. We demonstrate that use of tetrasodium EDTA (30 mg/ml) as a supplement to the gentamicin (5 mg/ml) antibiotic lock solution associated with systemic antibiotics completely eradicated Gram-positive and Gram-negative bacterial biofilms developed in totally implantable venous access ports. Gentamicin-EDTA lock was able to eliminate biofilms with a single instillation, thus reducing length of treatment. Moreover, we show that this combination was effective for immunosuppressed rats. Lastly, we demonstrate that a gentamicin-EDTA lock is able to eradicate the biofilm formed by a gentamicin-resistant strain of methicillin-resistant S. aureus. This in vivo study demonstrates the potential of EDTA as an efficient antibiotic adjuvant to eradicate catheter-associated biofilms of major bacterial pathogens and thus provides a promising new lock solution.

Journal Article

Xen26, Xen 26, Salmonella typhumurium, Animals; Biological Therapy/*methods; Colonic Neoplasms/chemistry/*therapy; Disease Models, Animal; Electrophoresis, Gel, Two-Dimensional; Male; Mass Spectrometry; Mice; Mice, Inbred BALB C; Proteome/analysis; Salmonella typhimurium/*growth & development/*pathogenicity

The use of bacteria has contributed to recent advances in targeted cancer therapy especially for its tumor-specific accumulation and proliferation. In this study, we investigated the molecular events following bacterial therapy using an attenuated Salmonella Typhimurium defective in ppGpp synthesis (DeltappGpp), by analyzing those proteins differentially expressed in tumor tissues from treated and untreated mice. CT26 murine colon cancer cells were implanted in BALB/c mice and allowed to form tumors. The tumor-bearing mice were treated with the attenuated Salmonella Typhimurium. Tumor tissues were analyzed by 2D-PAGE. Fourteen differentially expressed proteins were identified by mass spectrometry. The analysis revealed that cytoskeletal components, including vimentin, drebrin-like protein, and tropomyosin-alpha 3, were decreased while serum proteins related to heme or iron metabolism, including transferrin, hemopexin, and haptoglobin were increased. Subsequent studies revealed that the decrease in cytoskeletal components occurred at the transcriptional level and that the increase in heme and iron metabolism proteins occurred in liver. Most interestingly, the same pattern of increased expression of transferrin, hemopexin, and haptoglobin was observed following radiotherapy at the dosage of 14 Gy.

Journal Article

Xen8.1, Xen 8.1, S. aureus, IVIS, bioluminescence imaging, Analysis of Variance; Animals; Extracellular Space/*metabolism; Genetic Vectors/genetics; Green Fluorescent Proteins/metabolism; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Confocal; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Movement/*physiology; Neutrophils/*immunology/metabolism/physiology; Opsonin Proteins/metabolism; Skin Diseases, Bacterial/*immunology/metabolism; Toll-Like Receptor 2/metabolism

Neutrophil extracellular traps (NETs) are released as neutrophils die in vitro in a process requiring hours, leaving a temporal gap that invasive microbes may exploit. Neutrophils capable of migration and phagocytosis while undergoing NETosis have not been documented. During Gram-positive skin infections, we directly visualized live polymorphonuclear cells (PMNs) in vivo rapidly releasing NETs, which prevented systemic bacterial dissemination. NETosis occurred during crawling, thereby casting large areas of NETs. NET-releasing PMNs developed diffuse decondensed nuclei, ultimately becoming devoid of DNA. Cells with abnormal nuclei showed unusual crawling behavior highlighted by erratic pseudopods and hyperpolarization consistent with the nucleus being a fulcrum for crawling. A requirement for both Toll-like receptor 2 and complement-mediated opsonization tightly regulated NET release. Additionally, live human PMNs injected into mouse skin developed decondensed nuclei and formed NETS in vivo, and intact anuclear neutrophils were abundant in Gram-positive human abscesses. Therefore early in infection NETosis involves neutrophils that do not undergo lysis and retain the ability to multitask.

Journal Article

VivoTag, IVIS, Vivotag, Animals; Antibodies, Monoclonal/*diagnostic use/immunology/pharmacokinetics; Antigens, Neoplasm/*metabolism; Blotting, Western; Breast/immunology/metabolism/pathology; Breast Neoplasms/*diagnosis/immunology/metabolism; Carbonic Anhydrases/*metabolism; Carcinoma, Ductal, Breast/*diagnosis/immunology/metabolism; Carcinoma, Intraductal, Noninfiltrating/*diagnosis/immunology/metabolism; *Diagnostic Imaging; Female; Fluorescent Antibody Technique; Gene Expression Profiling; Humans; Luciferases/metabolism; Luminescent Measurements; Lymphatic Metastasis; Mice; Mice, Nude; Neoplasm Invasiveness; Oligonucleotide Array Sequence Analysis; RNA, Messenger/genetics; Real-Time Polymerase Chain Reaction; Tissue Array Analysis; Tissue Distribution; Tumor Cells, Cultured; Tumor Markers, Biological/genetics/metabolism

PURPOSE: To develop targeted molecular imaging probes for the noninvasive detection of breast cancer lymph node metastasis. EXPERIMENTAL DESIGN: Six cell surface or secreted markers were identified by expression profiling and from the literature as being highly expressed in breast cancer lymph node metastases. Two of these markers were cell surface carbonic anhydrase isozymes (CAIX and/or CAXII) and were validated for protein expression by immunohistochemistry of patient tissue samples on a breast cancer tissue microarray containing 47 normal breast tissue samples, 42 ductal carcinoma in situ, 43 invasive ductal carcinomas without metastasis, 46 invasive ductal carcinomas with metastasis, and 49 lymph node macrometastases of breast carcinoma. Targeted probes were developed by conjugation of CAIX- and CAXII-specific monoclonal antibodies to a near-infrared fluorescent dye. RESULTS: Together, these two markers were expressed in 100% of the lymph node metastases surveyed. Selectivity of the imaging probes were confirmed by intravenous injection into nude mice-bearing mammary fat pad tumors of marker-expressing cells and nonexpressing cells or by preinjection of unlabeled antibody. Imaging of lymph node metastases showed that peritumorally injected probes detected nodes harboring metastatic tumor cells. As few as 1,000 cells were detected, as determined by implanting, under ultrasound guidance, a range in number of CAIX- and CAXII-expressing cells into the axillary lymph nodes. CONCLUSION: These imaging probes have potential for noninvasive staging of breast cancer in the clinic and elimination of unneeded surgery, which is costly and associated with morbidities.