"Petri dish" on paper
Paper instead of a laboratory for bakposev
ChemPort.Ru based on the materials of Chemistry World: Paper device spots antibiotic-resistant bacteriaCanadian researchers have developed a paper-based device that tests the resistance of bacteria to certain antibiotics.
A simple system will be able to help medical personnel in areas remote from developed infrastructure to choose the most appropriate treatment for bacterial infections.
Testing bacteria for antibiotic sensitivity in order to select effective medicines is vital for the appropriate drug treatment of patients. Existing methods allow us to determine the most effective antibiotic in the fight against certain bacteria, but the equipment necessary for this is often expensive and highly qualified operators and appropriate conditions are needed to work on it.
In the course of the new work, Ratmir Derda and colleagues from the University of Alberta have developed a portable device made of paper and other cheap materials. The research team turned to high school seniors for help in creating and testing new devices in order to demonstrate how easy it is to make a diagnostic system and use it.
The Derda device consists of a paper base with a transparent plastic window on top of an area with a nutrient medium impregnating a sheet of thick filter paper. The culture medium has the same pattern of hydrophobic sites to ensure the distribution of samples evenly over the medium. Before sterilizing the device in an autoclave, two antibiotic zones are added to the medium. After autoclaving, the pigment allowing to determine the viability of the cell is applied to the culture medium, then a bacterial sample is added on top of the dye. At the end of all operations performed, the device is tightly closed and kept in the thermostat overnight.
In areas without bacterial growth, the dye remains blue. In places where bacterial growth is observed, the dye turns pink. The colors are easy to see through the plastic window of the device, so there is no need to open the device. The blue area around the antibiotic zones indicates that the bacteria are sensitive to antibiotics. Hydrophobic sites on the nutrient medium help to quantify the blue areas in order to have an idea of how sensitive bacteria are to certain antibiotics.
Preparation and application of the device is not difficult
M: nutrient medium; A: antibiotic zone; C: bacterial growth zone
A drawing from an article by Deiss et al. published in the journal Lab on a Chip:
Antimicrobial susceptibility assays in paper-based portable culture devices – VM.
Maria Lieberman, an expert on paper-based sensors from the University of Notre Dame in Indiana, USA, says that the work carried out by the researchers shows that living microorganisms can be grown and sorted by antibiotic resistance using paper-based devices that are small enough and weigh little enough to fit in a person's pocket.
The researchers also found that such a device can easily be stored for a long time. After proper staffing, which contains culture medium and antibiotics, such a kit can be stored for up to 70 days in a sealed bag. This storage capacity, along with the cheap components of the device and the ease of its use, makes the device very promising for use in remote areas.
Portal "Eternal youth" http://vechnayamolodost.ru05.11.2013