Two<unk> s 1a and 1b with antigens 2a and 2b on surface, which are recognized by two distinct antibodies, 3a and 3b, respectively A<unk>  or serovar is a distinct variation within a species of bacteria or virus or among immune cells of different individuals. These microorganisms, viruses, or cells are classified together based on their surface antigens, allowing the epidemiologic classification of organisms to the subspecies level. A group of serovars with common antigens is called a serogroup or sometimes serocomplex.<unk> ng often plays an essential role in determining species and subspecies. The Salmonella genus of bacteria, for example, has been determined to have over 2600<unk> s. Vibrio cholerae, the species of bacteria that causes cholera, has over 200<unk> s, based on cell antigens. Only two of them have been observed to produce the potent enterotoxin that results in cholera: O1 and O139.<unk> s were discovered by the American microbiologist Rebecca Lancefield in 1933.
Serotype
Isotype 
Strain 
Endotype
Strain pattern
Killing Season
Course 
Phenotype 