40 research outputs found
Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl beta-1,6 glucosamine specific antibody production using biofilm-embedded bacteria
Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides
coupled to protein carriers and polysaccharides embedded in liposomes administered together with
non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether
protective antibodies are directed to slime-associated known exopolysaccharides and could be
produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was
carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofil
BIIL 284 reduces neutrophil numbers but increases P. aeruginosa bacteremia and inflammation in mouse lungs
Background: A clinical study to investigate the leukotriene B4 (LTB4)-receptor antagonist BIIL 284 in cystic fibrosis (CF) patients was prematurely terminated due to a significantly increased risk of adverse pulmonary events. We aimed to establish the effect of BIIL284 in models of Pseudomonas aeruginosa lung infection, thereby contributing to a better understanding of what could have led to adverse pulmonary events in CF patients. Methods: P. aeruginosa DNA in the blood of CF patients during and after acute pulmonary exacerbations and in stable patients with non-CF bronchiectasis (NCFB) and healthy individuals was assessed by PCR. The effect of BIIL 284 treatment was tested in an agar bead murine model of P. aeruginosa lung infection. Bacterial count and inflammation were evaluated in lung and other organs. Results: Most CF patients (98%) and all patients with NCFB and healthy individuals had negative P. aeruginosa DNA in their blood. Similarly, the P. aeruginosa-infected mice showed bacterial counts in the lung but not in the blood or spleen. BIIL 284 treatment decreased pulmonary neutrophils and increased P. aeruginosa numbers in mouse lungs leading to significantly higher bacteremia rates and lung inflammation compared to placebo treated animals. Conclusions: Decreased airway neutrophils induced lung proliferation and severe bacteremia in a murine model of P. aeruginosa lung infection. These data suggest that caution should be taken when administering anti-inflammatory compounds to patients with bacterial infections
Production of poly-β-1, 6-N-acetylglucosamine by MatAB is required for hyphal aggregation and hydrophilic surface adhesion by Streptomyces
Microbial Biotechnolog
Theranostic body fluid cleansing : rationally designed magnetic particles enable capturing and detection of bacterial pathogens
We report on theoretical and experimental considerations on bacteria capturing and enrichment via magnetic separation enabling integrated diagnosis and treatment of blood stream infections. We show optimization of carrier-pathogen interactions based on a mathematical model followed by an experimental proof-of-concept study along with investigations on the process safety
Non-mucoid Pseudomonas aeruginosa expresses alginate in lungs of patients with cystic fibrosis and in a murine model.
Background. In patients with cystic fibrosis (CF), lung infection with mucoid Pseudomonas aeruginosa strains
overexpressing the exopolysaccaride alginate is preceded by colonization with nonmucoid strains. We investigated
the kinetics, impact of environmental signals, and genetics of P. aeruginosa alginate expression in a mouse model
and in patients with CF.
Methods. Using indirect immunofluorescence, microarray technology and real-time reverse-transcriptionpolymerase
chain reaction, we assessed alginate gene expression during aerobic and anaerobic growth of the nonmucoid
strain PAO1 in vitro, in a mouse lung-infection model and in sputum specimens from patients with CF infected
with nonmucoid or mucoid P. aeruginosa strains.
Results. Anaerobic conditions increased the transcription of alginate genes in vitro and in murine lungs within
24 h. Alginate production by PAO1 in murine lungs and by nonmucoid P. aeruginosa strains in patients with CF
was reversible after in vitro culture under aerobic conditions. A subpopulation of P. aeruginosa clones revealing
stable alginate production was detected in murine lungs 2 weeks after infection.
Conclusions. Anaerobiosis and lung infection rapidly induce alginate production by gene regulation in nonmucoid
P. aeruginosa. This trait may contribute to early persistence, leading to chronic P. aeruginosa infection
once stable mucoid strains are generated
Linear and cyclic oligo-beta(1→6)-D-glucosamines: Synthesis, conformations, and applications for design of a vaccine and oligodentate glycoconjugates
International audienc