A5026649949- Antibiotic Resistance in Bacteria
- Streptococcal Infections and Treatments
- Neonatal and Maternal Infections
- Influenza Virus Research Studies
- Antimicrobial Resistance in Staphylococcus
- Respiratory viral infections research
- Pneumonia and Respiratory Infections
- Bacterial Infections and Vaccines
- Immune Response and Inflammation
- Neonatal Respiratory Health Research
- Immunotherapy and Immune Responses
- Escherichia coli research studies
- Complement system in diseases
- Protein purification and stability
- Vibrio bacteria research studies
- Inhalation and Respiratory Drug Delivery
- Bacterial Identification and Susceptibility Testing
- Bacterial Genetics and Biotechnology
- Infective Endocarditis Diagnosis and Management
- Monoclonal and Polyclonal Antibodies Research
Sanofi (France)
2025
Sanofi (United States)
2024
Boston Children's Hospital
2009-2012
Harvard University
2009-2012
Unidad de Investigación en cuidados y servicios de salud (Investén-isciii)
2002-2004
Universitat de les Illes Balears
2002-2004
Servei de Salut de les Illes Balears
2004
Research Institute of Health Sciences
2004
Mediterranean Institute for Advanced Studies
2002
Hospital Universitario Son Dureta
2002
ABSTRACT Klebsiella pneumoniae is a common cause of gram-negative bacterial nosocomial pneumonia. Two surface polysaccharides, lipopolysaccharide (LPS) O side chain and capsular polysaccharide (CPS), are critical for the microorganism in causing sepsis, but little known about their role To investigate contribution pathogenesis K. pneumonia, we characterized host response to challenge with highly virulent clinical isolate or isogenic insertion-duplication mutants deficient CPS LPS murine...
The clinical burden caused by influenza can be mitigated the prophylactic use of seasonal vaccines. Their immunogen composition is revised biannually to optimally match antigenic drift hemagglutinin circulating virus strains. Antibodies directed against neuraminidase also correlate with protection influenza, yet evolution remains underexplored. To evaluate diversity N1 neuraminidase, we generated a panel immune sera 17 neuraminidases derived from human H1N1 strains that were isolated between...
The clinical burden caused by influenza can be mitigated the prophylactic use of seasonal vaccines. Their immunogen composition is revised biannually to optimally match antigenic drift hemagglutinin circulating virus strains. Antibodies directed against neuraminidase also correlate with protection influenza, yet evolution remains underexplored. To evaluate diversity N1 neuraminidase, we generated a panel immune sera 17 neuraminidases derived from human H1N1 strains that were isolated between...
ABSTRACT We recently described the use of mini-Tn 5 to generate complement-sensitive mutants derived from a complement-resistant Klebsiella pneumoniae clinical isolate deficient in lipopolysaccharide O side chain. One mutant with reduced capacity survive nonimmune human sera carried transposon inserted htrA gene. cloned and sequenced gene predicted deduced amino acid sequence that putative HtrA homolog contains structural features similar those previously proteins. To investigate biological...
ABSTRACT The airway epithelium represents a primary site for the entry of pathogenic bacteria into lungs. It has been suggested many respiratory pathogens, including Klebsiella pneumoniae , that adhesion and invasion lung epithelial cells is an early stage pneumonia process. We observed poorly encapsulated K. clinical isolates isogenic unencapsulated mutant invaded more efficiently than highly strains independent K type. By contrast, was completely avirulent in mouse model pneumonia, unlike...
Abstract Streptococcus pyogenes, or group A Streptococcus, is one of the most frequent causes pharyngitis and skin infections in humans. Many virulence mechanisms have been suggested to be involved infectious process. Among them binding bacterial cell surface complement regulatory proteins factor H, H-like protein 1 (FHL-1), C4b-binding protein. Previous studies indicate that these three regulators streptococcal involves M encoded by emm gene. M-type 18 strains are prevalent among clinical...
ABSTRACT The airway epithelium represents a primary site for contact between microbes and their hosts. To assess the role of complement in this event, we studied interaction A549 cell line derived from human alveolar epithelial cells major nosocomial pathogen, Klebsiella pneumoniae , presence serum. In vitro, found that C3 opsonization poorly encapsulated K. clinical isolates an unencapsulated mutant enhanced dramatically bacterial internalization by compared to highly isolates. Local...
Group A Streptococcus (GAS) can be internalized by epithelial cells, including keratinocytes from human skin or pharyngeal epithelium. Internalization of GAS cells has been postulated both to play a role in host defense and provide sanctuary site for survival. The cholesterol-binding cytolysin streptolysin O (SLO) appears enhance virulence part inhibiting internalization disrupting the lysosomal degradation GAS. We now report that low-level production SLO an inducible expression system...
Exposure to group A Streptococcus (GAS) has been shown induce maturation of dendritic cells (DC).To identify bacterial determinants that modulate DC activation in response GAS infection, we analyzed the induction human monocyte-derived following exposure clinical isolates.Unexpectedly, only 6 24 strains tested induced surface expression major histocompatibility complex class II and costimulatory molecules CD80 CD83 levels consistent with maturation. Rather, majority did not promote...
A survey of emm gene sequences and an analysis the pulsed-field electrophoretic profiles 30 Streptococcus pyogenes isolates with reduced susceptibilities to ciprofloxacin detected prevalence type 6 considerable genetic diversity among isolates. The mechanism resistance in these was based on point mutations topoisomerase IV subunit C encoded by parC, mainly replacement serine-79 alanine.
Abstract Neuraminidase (NA), the second most abundant surface glycoprotein on influenza virus, plays a key role in viral replication and propagation. Despite growing evidence showing that NA-specific antibodies correlate with resistance to disease humans, current licensed vaccines focus almost entirely hemagglutinin (HA) antigen. Here, we demonstrate recombinant NA (rNA) protein is highly immunogenic both naïve mice ferrets, as well pre-immune irrespective of level match preexisting...
Current influenza vaccines could be augmented by including recombinant neuraminidase (rNA) protein antigen to broaden protective immunity and improve efficacy. Toward this goal, we investigated formulation conditions optimize rNA physicochemical stability. When in sodium phosphate saline buffer (NaPBS) was frozen thawed (F/T), the tetrameric structure transitioned from a "closed" an "open" conformation, negatively impacting functional activity. Hydrogen deuterium exchange experiments...
Abstract The clinical burden caused by influenza can be mitigated the prophylactic use of seasonal vaccines. Their immunogen composition is revised biannually to optimally match antigenic drift hemagglutinin circulating virus strains. Antibodies directed against neuraminidase also correlate with protection influenza, yet evolution remains underexplored. To evaluate diversity N1 neuraminidase, we generated a panel immune sera 17 neuraminidases derived from human H1N1 strains that were...