You should clarify what you want to measure about it: its diameter, mass, weight, color, etc. If you want to measure its diameter, that would usually be specified in microns (= micrometers).
No. The closest metric unit is the meter.
You would measure that in grams, or milligrams.
centimeter
The basic metric unit of measure for length is the meter (m).
gram
meters There is no special unit for the size of bacteria, so traditional systems of length are used. As most people who care about bacteria enough to measure them are scientists, and most scientists use metric (the better to understand each other), the metric system is used. Now, the basic unit of length in the metric system is a meter, but that is much to big to measure a bacterium with. Conveniently, metric units come with a series of prefixes to express multiples or fraction of a unit (you may know of centimeters, which are hundredths of a meter, and kilometers, which are a thousand meters) In general, bacteria will be measured in micrometers, which is to say millionths of a meter. In general, a bacterium will measure anywhere from one to ten nanometers.
metric unit
kilograms
A microgram.
meters
miles?
Litres.
Tonnes
Millimeters
barman curls -2
The metric unit of length is the 'meter'.
You would use meters.