New Delhi, Aug. 4 -- The United States, which had a frustrating swim world championships, ended on a high note Sunday with a world record in the women's 4x100 medley relay in the last event of the eight-day championships.

The Americans swam a time of 3 minutes, 49.34 seconds, breaking their own old mark of 3:49.63 set a year ago in the Paris Olympics.

The United States finished with nine gold medals and 29 overall, ahead of Australia with eight gold and 20 overall. France and Canada were next in the gold-medal count with four gold medals. The 18-year-old Canadian star Summer McIntosh won all four golds.

The Americans battled a case of "acute gastroenteritis" picked up at a training camp in Thailand. The malady clearly affected the team...