She eclipsed the  record shared by Tracy Caulkins and Libby Trickett
associated press
Barcelona, 4 August
Missy Franklin claimed her record sixth gold medal of the world championships on Sunday night, swimming the leadoff leg for the Americans in the 400-meter medley relay. She gave the U.S. a slight lead, and her teammates — Jessica Hardy, Dana Vollmer and Megan Romano — made it look easy from there. The winning time was 3 minutes, 53.23 seconds, nearly two seconds ahead of runner-up Australia.
The 18-year-old Franklin became the most decorated female swimmer ever at the worlds and improved on her performance at the London Olympics, where she was one of the biggest stars with four golds and a bronze.
She eclipsed the women’s record that had had been shared by Tracy Caulkins, who won five times at the 1978 worlds, and Libby Trickett, who did it in 2007.
Franklin also joins Michael Phelps, Mark Spitz, Australia’s Ian Thorpe and East Germany’s Kristin Otto as the only swimmers to capture as many as six golds at either worlds or an Olympics. "I still can’t really believe that it happened," Franklin said. The Aussies took the silver in 3:55.22. Russia held on for the bronze (3:56.47). Franklin completed a grueling week in which she competed in eight events. She dropped out of the 50 backstroke after swimming in the preliminaries of the non-OIympic event, wanting to focus on more important races, and took fourth in the 100 freestyle.
The victory in the final race of the meet came after a stunning result for the Americans in the next-to-last event. The men appeared to have an easy victory in their 400 medley relay, but 19-year-old breaststroker Kevin Cordes, the least experienced member of the foursome, left too soon on the exchange between the first and second legs.
The U.S. team, which touched nearly one and a half seconds ahead of France, was disqualified. The French moved up to take the gold, while the silver went to Australia and Japan snatched the bronze. Franklin stood above them all — even though, amazingly enough, she was not even chosen the top female swimmer of the meet.
That award went to fellow American Katie Ledecky, who won four golds and set two world records. She edged out Franklin based on a formula that doesn’t count the relays and gives bonus points for world marks.
Sun was named the top male swimmer after sweeping the freestyle distance events. He closed with a victory in the 1,500 free, adding to his triumphs in the 400 and 800.  Japan’s Daiya Seto held off American Chase Kalisz to  win the 400 individual medley. Yuliya Efimova won the 50m breaststroke.