Staphylococcus aureus<unk>  on an indwelling catheter A<unk>  comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the<unk>  produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes".<unk> s may form on living or non-living surfaces and can be prevalent in natural, industrial, and hospital settings. The microbial cells growing in a<unk>  are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium.<unk> s can form on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease. Microbes form a<unk>  in response to a number of different factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. A cell that switches to the<unk>  mode of growth undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated. A<unk>  may also be considered a hydrogel, which is a complex polymer that contains many times its dry weight in water.<unk> s are not just bacterial slime layers but biological systems; the bacteria organize themselves into a coordinated functional community.<unk> s can attach to a surface such as a tooth or rock, and may include a single species or a diverse group of microorganisms. Subpopulations of cells within the<unk>  differentiate to perform various activities for motility, matrix production, and sporulation, supporting the overall success of the<unk> . The<unk>  bacteria can share nutrients and are sheltered from harmful factors in the environment, such as desiccation, antibiotics, and a host body's immune system. A<unk>  usually begins to form when a free-swimming bacterium attaches to a surface.
Biofilm
Tocolytic
Speculum 
Dentition
Indicator bacteria
Microgenia
Exudate
Mycobiota