Drugs-China-Resources-Drugs-China-Resources-Therapy-Apdt-Strategy-Inactivate-Bacteria-r
This study was designed to investigate the antibacterial effect of a novel photosensitizer S-Porphin sodium METHODS: The plate counting method was used to evaluate the antimicrobial effect of S-PS-aPDT. The bacterial viability was detected by SYTO9/PI. The intracellular reactive oxygen species (ROS) generation was estimated by electron spin resonance spectroscopy and flow cytometry. The destruction of bacteria and biofilm was observed by scanning electron microscope (SEM) and atomic force RESULTS: The aPDT induced antibacterial effect in S. aureus and MDR S. aureus was S-PS concentration- and light dose-dependent.
S. aureus exhibited much level, as well as morphological damages under AFM observation. When pretreated with the efflux pump inhibitors (EPIs), the intracellular uptake of S-PS in MDR S. aureus increased and the coupled aPDT produced significantly enhanced CONCLUSION: S-PS-aPDT exhibited excellent bactericidal activity in plankton and biofilms. S-PS might be a good candidate for using in PDT anti-bacterial field. The introduction of EPIs could effectively improve the killing effect of MDR S. Hyperbiofilm Formation by Bordetella pertussis Strains Correlates with Enhanced Pertussis, or whooping cough, caused by the obligate human pathogen Bordetella pertussis is undergoing a worldwide resurgence.
The majority of studies of this pathogen are conducted with laboratory-adapted strains which may not be representative of the species as a whole. Biofilm formation by B. pertussis plays an important role in pathogenesis. We conducted a side-by-side comparison of the biofilm-forming abilities of the prototype laboratory strains and the currently circulating isolates from two countries with different vaccination programs. Compared to the reference strain, all strains examined herein formed biofilms at high levels. Biofilm structural analyses revealed country-specific differences, with strains from the United States forming more structured biofilms. Bacterial hyperaggregation and reciprocal expression of biofilm-promoting and -inhibitory factors were observed in clinical isolates.
An association of increased biofilm formation with augmented epithelial cell adhesion and higher levels of bacterial colonization in the mouse nose and trachea was detected. To our knowledge, this work links for the first time increased biofilm formation in bacteria with a colonization advantage in an animal model. We propose that the enhanced biofilm-forming capacity of currently circulating strains contributes to their persistence, transmission, and An optical microsensor to measure fluorescent light intensity in biofilms. Rhamnose-containing polysaccharides have developed an optical microsensor to quantify fluorescent light intensity distribution in biofilms. The optical system consisted of a beam splitter, light couplers, filters and a spectrophotometer able to accept the fiberoptic cable to measure fluorescent light intensity. The emitted light, fluorescence from the biofilm, was collected at the tip of the optical microsensor and was transferred to a spectrophotometer via a fiberoptic cable. The total fluorescent light intensity was evaluated from the emission spectrum by numerical integration.
The newly developed fiberoptic microsensor was tested using a Staphylococcus aureus strain producing yellow fluorescent protein (YFP) grown as biofilm. We used a 405-nm violet laser diode for excitation, and measured the emission intensity between 480 nm and 540 nm. The optical microsensor that quantifies fluorescent light intensity is a promising tool in biofilm research which often requires detection and quantification of fluorescent light intensity distribution generated by various fluorescent proteins. Lack of galactose or galacturonic acid in Bradyrhizobium japonicum USDA 110 exopolysaccharide leads to different symbiotic responses in soybean. Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT Exopolysaccharide (EPS) and lipopolysaccharide (LPS) from Bradyrhizobium japonicum are important for infection and nodulation of soybean (Glycine max), although their roles are not completely understood. To better understand Colanic acid polymer , we constructed mutants in B. japonicum USDA 110 impaired in galactose or galacturonic acid incorporation into the EPS without affecting the LPS.
The derivative LP 3010 had a deletion of lspL-ugdH and produced EPS without galacturonic acid whereas LP 3013, with an insertion in exoB, produced EPS devoid of both galactosides.
