Treffers continued his dominance of the 50 metre backstroke to win his fourth Australian title on Thursday night, confirming his place was the country's best short-distance racer.

But because the event is not part of the Olympic Games program, Swimming Australia will not send Treffers to the world titles in Budapest later this year.

Instead, the 25-year-old will turn his attention to the world university games and start his preparation for a home Commonwealth Games campaign.

Treffers won a gold medal in the 50 metre backstroke at the Commonwealth Games in Glasgow in 2014, but failed in his bid to force his way on to the Olympic team last year.

"Without the opportunity to race in Budapest, I've got to look forward to the Commonwealth Games," Treffers said.

"Swimming Australia doesn't select someone for it because I guess their main focus in the Olympic Games and Olympic events.

"In that respect it's frustrating because I don't get the chance to compete at the world championships and try to win a medal for Australia.

"But it is my best event and I've just got to focus on what I can control to keep working towards the Commonwealth Games."

Treffers relocated to the Gold Coast the end of last year for a fresh start to his swimming career after missing out on a spot on the Olympic team.

He is working with former world champion and Olympic gold medallist Ashley Callus in the hope of defending his title and taking his swimming in a new direction.

But it was an old favourite that got Treffers back in the winner's book at the national titles in Brisbane, beating rival Mitch Larkin by 0.3 seconds to win the 50 metres backstroke.

It was sweet redemption for Treffers, who lost his national title crown last year after battling illness at the Australian championships.

Treffers was satisfied with the win, but says he can improve his time despite finishing only 0.36 seconds outside of his Australian record.

"I was a bit disappointed with the time and I felt like I could have gone faster," Treffers said.

"But I look at that as motivation that I've got a lot more to improve on and that there's a lot more improvement in me.

"It was great to get the win but for me it's all about looking forward from now on."