How to add some text between date and hour with twig localizeddate extension

This is my code

{{ commentaire.dateCommentaire|localizeddate('medium', 'medium') }}

and this is the output

12 MARS 2016 20:35:21

I'd like to add a text between date and hour to be like this

12 MARS 2016 à 20:35:21

How can I do this ?