germs and cells
There is no microorganism there which is common in athletes.
There are a number of bacteria that can cause UTIs. E. coli is the most common cause.
i think it is mycobacterium bovis, (which is the one you can catch from cattle), which is much more uncommon than mycobacterium tuberculosis, (which is the most common one ).
You find a lot of bugs in forest, and also a lot of microorganisms (such as fungi, moss, ect). So altogether it is toss up between bugs being the most common or microorganism's.
fungi
Virus is most harmful
Microorganisms are tiny living organisms like bacteria and viruses. Scientists study how these microorganisms impact our health and environment.
For Bacteria: E. coliFor Eukaryotes: Probably Saccharomyces cerevisiae (the yeast that makes beer and bread) or Candida albicans (Very common yeast that causes infections in humans).
fungi is a microorganism.
Aerobic microoganisms
Viruses are very different from the most microorganisms and they are classified as microbes.
A microorganism is called a "pathogen".