Typhi-Biofilm-Capsule-Production-Capability-Subsequent-Methods-Cell-Release-Biofilm-Vitro-Electron-Microscopy-Cytotoxicity-Cells-h
Functionality of the biofilm diffusion barrier was tested against ciprofloxacin. Biofilm production was graded and semi-quantified RESULTS: Out of 30 isolates, 23 produced biofilm. The average post-treatment detection of S. Typhi in blood was 7-13 days and in stool was 13-32 days. A fall in cell count from 10⁴ to approximately 10¹ over the course of 3 days as compared to total elimination of planktonic cells in 16 h after ciprofloxacin application substantiated the protective role of biofilm. Lactic dehydrogenase release ranged from 38% in non-biofilm producers to 97% in the highest biofilm producers, indicating increased pathogenic behavior.
CONCLUSIONS: The period of S. Typhi clearance from typhoid patients after recovery was found to be directly related to biofilm production capability. Anti-biofilm investigation of graphene/chitosan nanocomposites against biofilm 510275, PR China; Medical Microbiology & Marine Pharmacology Laboratory, Tamil Nadu, India; Southern Marine Science and Engineering Guangdong Laboratory 510275, PR China; Southern Marine Science and Engineering Guangdong Laboratory In this study graphene/chitosan nanoparticles (GR/CS NCs) were developed. The homogenous combination of GR and CS was confirmed by FTIR spectroscopy. The combination of CS with GR sheets reduced the XRD intensity of the GR peak in GR/CS NCs, while TEM images revealed the immobile CS coating of GR sheets. Further, the anti-biofilm activity of GR/CS NCs was tested. The tests showed that the formation of biofilm by Pseudomonas aeruginosa and Klebsiella pneumoniae was inhibited at 40□g/mL GR/CS NCs up to 94 and 92 %, respectively.
The intracellular and cell surface damage of the bacteria was observed by CLSM and SEM. Also, GR/CS NCs produced a toxic effect of 90 % on Artemia franciscana at 70□g/mL upon 24 h incubation. The recorded properties of the synthesized GR/CS NCs qualify them as potential agents against multi-drug resistant Microfluidic bioanalytical system for biofilm formation indication. Subdivision of the Federal State Budgetary Research Institution Saratov Federal Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), Saratov, Subdivision of the Federal State Budgetary Research Institution Saratov Federal Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), Saratov, The formation of biofilms is a key factor that researchers must consider when they work with bacterial cultures. We describe a new microfluidic bioanalytical sensory system for indicating biofilm formation. The method is demonstrated with Pseudomonas bacteria as an example and is based on the real-time recording of cell-polarizability changes caused by an alternating electric field. Control experiments using phase-contrast microscopy and traditional microbiological plating were done that proved biofilms had formed.
The physical picture was described of the sensor-signal changes during cell transition from planktonic to biofilm growth. This transition was indicated by the appearance of a peak-shaped signal at 500 kHz and by an increase in the recorded relaxation time. Phenomena of increase in the signal relaxation time from 2 s for planktonic to 25 s for biofilm cells. The proposed microfluidic sensor system for indicating biofilm formation holds much promise, because it ensures an analysis time of about 20-30 min. An added bonus is that for this system there is no need to grow bacterial biofilms in a sensor and the flow cell is reusable. Colanic acid -based quorum sensing stimulates biofilm formation by Salmonella Enteritidis in anaerobic conditions. Quorum sensing regulates a variety of phenotypes in bacteria including the production of virulence factors.
Salmonella spp. have quorum sensing systems is incomplete in that the bacterium relies on the synthesis of signaling molecules by other microorganisms. Exopolysaccharides aimed to evaluate the influence of the AI-1 N-dodecanoyl-DL-homoserine lactone (C12-HSL) on the growth, motility, adhesion, and biofilm formation of Salmonella enterica serovar Enteritidis PT4 578 on a polystyrene surface. Experiments were conducted at 37 °C in anaerobic tryptone soy broth supplemented with C12-HSL and/or a mixture of four synthetic swarming, and twitching motility were not altered in the presence of C12-HSL and/or furanones under anaerobic conditions.
