Streptococcus agalactiae

Etymology
Streptococcus agalactiae:

streptos: "chain" (from greek στρεπτός, meaning "twisted", but used medically to refer to "chains")

coccos: "berry" (from greek κόκκος, meaning "berry")

a: "no" (greek prefix indicating negation)

galactiae: "milk" (from greek  γαλακτ- ( galact-), meaning "milk"). (that's where we get the word galaxy from, referring to the "milky way")

Explanation
The bacteria Streptococcus agalactiae looks like a chain (streptos) of small round berry-like cells (coccos), which causes a variety of infections, particularly in newborns (such as septicemia and meningitis). In cows, it infects the udders, preventing them from producing milk (agalactiae).

Synonyms
Group B Streptococcus