MELBOURNE :Backstroke queen Kaylee McKeown marked herself a major threat for the 200 metres individual medley gold at the Paris Olympics as she shattered a national record at the Australian Open Championships on Wednesday. McKeown will defend her 100m and 200m backstroke titles at Paris but a separate showdown with Canadian sensation Summer McIntosh beckons for the medley title after the Australian's sizzling time of 2:06.99 at the Gold Coast Aquatic Centre. McKeown's swim, the best this year