15-Letter Words Matching ____E____O_____

There are 17 15-letter words that match ____E____O_____. 4 are common words, such as BACTERIOLOGICAL and BACTERIOLOGISTS. A rarer one is PREREVISIONISTS. In this set, I is the most frequent open letter (16 words). 4 words contain a doubled letter.

Full list 17

bacteriologicalbacteriologistsepidemiologistssegregationistsconservatorshipdessertspoonfulepidemiologicalcholecystokinincooperationistsdialectologicaldialectologistsecclesiologicalecclesiologistshysterectomizednonmetaphoricalnonmetropolitanprerevisionists

About this list

Words
17 (4 common words)
Common example
bacteriological
Rare example
prerevisionists
Doubled letters
4
Ending in S
7
Most frequent letter
I (16)

Questions

How many 15-letter words matching ____e____o_____ are there?

17. 4 of them are common words.

What is a common example?

BACTERIOLOGICAL is among the common words in this set.