There are some peculiarities of the use of APA in biology. It concerns specific terms and names when writing academic paper in biology.

Here, names of species, bacteria varieties, and genera are italicized.

Examples:

Clostridium difficile

Homo sapiens

As for references, such names are italicized in the title as well:

Lessa, F. C., Mu, Y., Bamberg, W. M., Zintars, G., Beldavs, M. S., Dumyati, G. K., … McDonald, L. C. (2015). Burden of Clostridium difficile infection in the United States. The New England Journal of Medicine, 372, 825-834. doi: 10.1056/NEJMoa1408913

When referring to cultural terms or cultural names of some objects, they should be capitalized, for example, the Indigenous population.