It is also a name for the page and a half of indecipherable foreplay used in university physics textbooks before they give you the formula for something. Engineering student: I forgot the formula for the volume of a sphere, but I was able to figure it out from the area of a circle using calculus.
Bacterial is the taxonomy, i.e. the rank-based classification, of bacteria. In the scientific classification established by Carolus Linnaeus, each species has to be assigned to a genus (binary nomenclature), which in turn is a lower level of a hierarchy of ranks (family, suborder, order, subclass, class, division/phyla, kingdom and domain).
The family Enterobacteriaceae is the largest and most heterogeneous collection of medically important gram-negative bacilli and are commonly isolated from clinical specimens. There are over fourteen genera that been described to cause human infection but by far the most important single species is Escherichia coli.