William Hsiao

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Using a systems biology approach, we discovered and dissected a three-way interaction between the immune system, the intestinal epithelium and the microbiota. We found that, in the absence of B cells, or of IgA, and in the presence of the microbiota, the intestinal epithelium launches its own protective mechanisms, upregulating interferon-inducible immune(More)
Acinetobacter baumannii has recently emerged as a significant global pathogen, with a surprisingly rapid acquisition of antibiotic resistance and spread within hospitals and health care institutions. This study examines the genomic content of three A. baumannii strains isolated from distinct body sites. Isolates from blood, peri-anal, and wound sources were(More)
OBJECTIVE Despite widespread use of antibiotics for the treatment of life-threatening infections and for research on the role of commensal microbiota, our understanding of their effects on the host is still very limited. DESIGN Using a popular mouse model of microbiota depletion by a cocktail of antibiotics, we analysed the effects of antibiotics by(More)
This article summarizes advances in the field of host-microbe interactions in the gut. The human gut is home to a complex community of microbes (the microbiota) that plays a critical role in host nutrient acquisition and metabolism, development of intestinal epithelial cells, and host immune system. Genetic background, nutritional status, and environmental(More)
In this study, we identified critically ill patients with Acinetobacter baumannii bacteremia and examined perirectal surveillance cultures for the presence of genetically related A baumannii strains using pulsed-field gel electrophoresis to determine whether gut colonization preceded clinical infection. Seven patients with imipenem-resistant A baumannii(More)
BACKGROUND Imipenem-resistant Pseudomonas aeruginosa (IRPA) is an emerging problem. The causal role of antibiotic selective pressure versus patient-to-patient transmission has not been assessed using a large cohort. METHODS Patients who were admitted to the medical and surgical intensive care units (ICUs) at the University of Maryland Medical Center from(More)
Endodontic infections are a leading cause of oro-facial pain and tooth loss in western countries, and may lead to severe life-threatening infections. These infections are polymicrobial with high bacterial diversity. Understanding the spatial transition of microbiota from normal oral cavities through the infected root canal to the acute periapical abscess(More)
MOTIVATION Direct sequencing of microbes in human ecosystems (the human microbiome) has complemented single genome cultivation and sequencing to understand and explore the impact of commensal microbes on human health. As sequencing technologies improve and costs decline, the sophistication of data has outgrown available computational methods. While several(More)
Neutrophil antigens are involved in a variety of clinical conditions including transfusion-related acute lung injury (TRALI) and other transfusion-related diseases. Recently, there are five characterized groups of human neutrophil antigen (HNA) systems, the HNA1 to 5. Characterization of all neutrophil antigens from whole genome sequencing (WGS) data may be(More)