Using mesoscopic confocal microscope, the researchers found that bacterial biofilm is a network of channels that are recovered after destruction of the structure of colonies and overlap between the two cultures. Probably, the system of channels needed for the transport of nutrients, and it can be used to deliver antibiotics into the biofilm. Article published in the journal The ISME Journal.
Bacteria often grow in biofilms — colonies that are attached to surfaces and immersed in a complex extracellular matrix. The structure of biofilms, which protects the microorganisms from adverse environmental conditions, including the action of antibiotics, is poorly understood. The fact that conventional optical microscopy allows us to consider either individual bacteria at high magnification, or the colony as a whole — but with low resolution.
Scientists from the Scottish University of Strathclyde under the direction of Liam Rooney (Liam Rooney) investigated the structure of biofilms of bacteria Escherichia coli using mesoscopic confocal microscope Mesolens. This is a great lens with four magnification and a numerical aperture of 0.47, which is about five times more than the ordinary lens this increase. The microscope allows you to record the field of view in six square millimeters with a lateral resolution of 700 nm and an axial (depth) of 7 micrometers — that is, to consider the individual bacteria and the structure of a biofilm at the same time (although I Mesolens not tried to apply in Microbiology).
Using mesoscope scientists saw that the bacterial culture is a three-dimensional network of channels with a width of about 15 micrometers, Even after the structure of the colony broke, the channels are again formed, although the living bacteria in the biofilm has become less. Hence, the formation of channels is a property not of individual cells and colonies as a whole.