Adjunctive transferrin to reduce the emergence of antibiotic resistance in Gram-negative bacteria.

BACKGROUND: New strategies are needed to slow the emergence of antibiotic resistance among bacterial pathogens. In particular, society is experiencing a crisis of antibiotic-resistant infections caused by Gram-negative bacterial pathogens and novel therapeutics are desperately needed to combat such diseases. Acquisition of iron from the host is a nearly universal requirement for microbial pathogens-including Gram-negative bacteria-to cause infection. We have previously reported that apo-transferrin (lacking iron) can inhibit the growth of Staphylococcus aureus in culture and diminish emergence of resistance to rifampicin. OBJECTIVES: To define the potential of apo-transferrin to inhibit in vitro growth of Klebsiella pneumoniae and Acinetobacter baumannii, key Gram-negative pathogens, and to reduce emergence of resistance to antibiotics. METHODS: The efficacy of apo-transferrin alone or in combination with meropenem or ciprofloxacin against K. pneumoniae and A. baumannii clinical isolates was tested by MIC assay, time-kill assay and assays for the selection of resistant mutants. RESULTS: We confirmed that apo-transferrin had detectable MICs for all strains tested of both pathogens. Apo-transferrin mediated an additive antimicrobial effect for both antibiotics against multiple strains in time-kill assays. Finally, adding apo-transferrin to ciprofloxacin or meropenem reduced the emergence of resistant mutants during 20 day serial passaging of both species. CONCLUSIONS: These results suggest that apo-transferrin may have promise to suppress the emergence of antibiotic-resistant mutants when treating infections caused by Gram-negative bacteria.

Monoclonal Antibody Protects Against Acinetobacter baumannii Infection by Enhancing Bacterial Clearance and Evading Sepsis.

Background: Extremely drug-resistant (XDR) Acinetobacter baumannii is one of the most commonly encountered, highly resistant pathogens requiring novel therapeutic interventions. Methods: We developed C8, a monoclonal antibody (mAb), by immunizing mice with sublethal inocula of a hypervirulent XDR clinical isolate. Results: C8 targets capsular carbohydrate on the bacterial surface, enhancing opsonophagocytosis. Treating with a single dose of C8 as low as 0.5 µg/mouse (0.0167 mg/kg) markedly improved survival in lethal bacteremic sepsis and aspiration pneumonia models of XDR A. baumannii infection. C8 was also synergistic with colistin, substantially improving survival compared to monotherapy. Treatment with C8 significantly reduced blood bacterial density, cytokine production (tumor necrosis factor α, interleukin [IL] 6, IL-1ß, and IL-10), and sepsis biomarkers. Serial in vitro passaging of A. baumannii in the presence of C8 did not cause loss of mAb binding to the bacteria, but did result in emergence of less-virulent mutants that were more susceptible to macrophage uptake. Finally, we developed a highly humanized variant of C8 that retains opsonophagocytic activity in murine and human macrophages and rescued mice from lethal infection. Conclusions: We describe a promising and novel mAb as therapy for lethal, XDR A. baumannii infections, and demonstrate that it synergistically improves outcomes in combination with antibiotics.

Neurodegenerative Diseases: The Value of Early Predictive End Points.

Use of early predictive biomarkers of neurodegenerative disease in phase I clinical trials may improve the translation of novel drug therapies from preclinical development through late-stage studies. This article provides a categorical summary of promising biomarker approaches or clinical end points in molecular, cellular, metabolic, electrophysiological, or clinical function that can be used to predict or quantify the progression of neurodegenerative disorders and guide program support.

Shared Decision Making and Patient-Centered Care in Israel, Jordan, and the United States: Exploratory and Comparative Survey Study of Physician Perceptions.

BACKGROUND: Shared decision making (SDM) is a health communication model that evolved in Europe and North America and largely reflects the values and medical practices dominant in these areas. OBJECTIVE: This study aims to understand the beliefs, perceptions, and practices related to SDM and patient-centered care (PCC) of physicians in Israel, Jordan, and the United States. METHODS: A hypothesis-generating comparative survey study was administered to physicians from Israel, Jordan, and the United States. RESULTS: A total of 36 surveys were collected via snowball sampling (Jordan: n=15; United States: n=12; Israel: n=9). SDM was perceived as a way to inform patients and allow them to participate in their care. Barriers to implementing SDM varied based on place of origin; physicians in the United States mentioned limited time, physicians in Jordan reported that a lack of patient education limits SDM practices, and physicians in Israel reported lack of communication training. Most US physicians defined PCC as a practice for prioritizing patient preferences, whereas both Jordanian and Israeli physicians defined PCC as a holistic approach to care and to prioritizing patient needs. Barriers to implementing PCC, as seen by US physicians, were mostly centered on limited appointment time and insurance coverage. In Jordan and Israel, staff shortage and a lack of resources in the system were seen as major barriers to PCC implementation. CONCLUSIONS: The study adds to the limited, yet important, literature on SDM and PCC in areas of the world outside the United States, Canada, Australia, and Western Europe. The study suggests that perceptions of PCC might widely differ among these regions, whereas concepts of SDM might be shared. Future work should clarify these differences.