Swiss trains are often seen also in Italy, especially in cargo traffic. Here one Bombardier TRAXX multiple electric system locomotive of Swiss federal railways SBB is hauling two similar locomotives of SBB's competitor company BLS Cargo. These locomotives are known as Re 484 in Switzerland and E.484 in Italy.
Picture from Domodossola in June 2020 by Stefano Bressanelli.

The Austrian federal railways ÖBB run their own EuroCity express trains from Austria over the Brenner pass to Italy. These trains run all the way to Venezia and Milano.
Picture from Bologna Centrale 1.12.2014 by Ilkka Siissalo.

Two Austrian Br 1144 locomotives have brought a very heavy cargo train over the mountains and over the border to Italy, but since they cannot move with the Italian DC currency, a small Italian diesel is needed to switch them to the other end of the station where the Austrian 15kV AC currency begins.
Picture from Tarvisio Boscoverde station 6.7.2015 by Ilkka Siissalo.

An old French TGV train no.4502 on the route Paris to Milano.
Picture from Milano Porta Garibaldi station 7.7.2019 by Ilkka Siissalo.

Side view of the same old French TGV train as above.
Picture from Milano Porta Garibaldi station 7.7.2019 by Ilkka Siissalo.

Two German G 2000 diesel shunter locomotives of Ralion (nowadays again DB Cargo) parked at Bergamo. Bergamo was the end station of the Rollende Landstrasse (rolling highway) service of DB, bringing lorries from Germany via Switzerland over the Alps to Italy or the other way round.
Picture from Bergamo 11.7.2007 by Ilkka Siissalo.