Thanks for the correction. I borrowed the spanish plural.
Trivia: Spanish would distinguish between "una bacteria" (one bacterium) feminine noun in Spanish so it ends in "a", and between "una colonia de bacterias" (a colony of bacteria). Bacterias would be the correct plural in Spanish. English works a little different here.
English still prefers using the Latin and Greek plurals for words borrowed from, or indeed inherited from, Latin and Greek. "medium"/"media", "datum"/"data", "stratum"/"strata", "stigma"/"stigmata", "bacterium"/"bacteria", "schema"/"schemata" ...
The exceptions are things like
* mixed modern coinages (e.g. "television", a Latin suffix with a Greek prefix),
* divergent modern coinages ("bicycle" is not Greek "κύκλος" nor Latin "cyclus", and was taken from French),
* words not attested in the plural in the original language (e.g. "virus", only attested in the singular),
* words not actually singular in the original language (e.g. "ignoramus" is a verb in Latin, first person plural), and
* things that have since diverged (e.g. "hippopotamus", where "ποταμός" meaning "river" is "-ός" and hence "ποταμοι" in Greek but the word that English has came via Late Latin).
English generally pluralizes these things the Germanic way with "-es"/"-s", although pluralizing "hippopotami" as Latin is well attested and "bicycles" is the French plural.
Getting English speakers to remember "spaghetto", "panino", "confetto", "graffito", "paparazzo", or even "die" (singular of "dice") is somewhat hard. (-:
Trivia: Spanish would distinguish between "una bacteria" (one bacterium) feminine noun in Spanish so it ends in "a", and between "una colonia de bacterias" (a colony of bacteria). Bacterias would be the correct plural in Spanish. English works a little different here.