Wollongong's swimming golden girl Emma McKeon is firing on all cylinders as the 2016 Olympic Games countdown ticks over to 12 months.

The 21-year-old claimed her first gold medal of the 2015 World Championships in Russia on Sunday, helping Australia's 4x100 metres freestyle relay to the top of the podium ahead of Netherlands and the US.

She teamed up with Emily Seebohm, and sisters Bronte and Cate Campbell to clock a meet record three minutes 31.48 seconds to turn around what loomed as a disastrous first day in Kazan.

Bronte Campbell's sizzling 51.77s third leg set up her sister and world 100m champion Cate to comfortably bring home the women's relay victory.

Australia - the world record holders with 3:30.98 - avenged their 2013 world titles silver finish behind the US.

"To come second [in 2013] was amazing, but to stand together on the podium and sing the national anthem with your big sister is something not many get to do. It's my highlight of the year," Bronte Campbell said.

The Netherlands (3:33.67) took silver and defending champions the US bronze (3:34.61).

It was the perfect way to kick off the championship's for McKeon, who became a household name around Australia following her breakout Commonwealth Games campaign in 2014.

However, it is individual success she will be hunting for in Russia as she turns both eyes toward next year's Games.

Wednesday signals 12 months to the opening ceremony in Rio and McKeon is shaping as one of the country's brightest medal hopes.

She contested the 100m butterfly final overnight on Monday, and will take on the non-Olympic 50m butterfly event, as well as the 200m freestyle later in the week.

The women's 4x200m freestyle and 4x100m medley are also on the agenda in Russia for McKeon.

Older brother David McKeon, meantime, is also pressing his Rio claims at the world championships.

The women's team gold medal on Sunday was a shining light on an otherwise dark day for Australia.

Australian coach Jacco Verhaeren appeared livid over the Australian men's horror start to the eight-day meet.

World champion Christian Sprenger (100m breaststroke), world No1 Mack Horton (400m freestyle) and the fancied men's 4x100m freestyle relay team failed to qualify for their respective finals.

"It's a world championships and you don't get away with an easy swim ... you have to step up," Verhaeren said of the men's shocker.

Jess Ashwood opened the team medal tally with 400m freestyle bronze.

Ashwood, 22, claimed 400m bronze (4:03.34 PB) behind American defending champion and world record holder Katie Ledecky (3:59.13, meet record).