Food being served at McDonald's outlets in the UAE is free from E. coli bacteria, UAE authorities have said on Friday.

The Ministry of Climate Change and Environment said in a post that food being served at the fast food chain is safe. It added, "UAE regulatory authorities continue to conduct regular inspections to ensure that all food facilities meet safety and quality standards.

In the US, an E. coli outbreak sickened people across the West and Midwest, with one dead and 10 hospitalised due to serious complications, according to the US Centres for Disease Control and Prevention.

The CDC and McDonald's are scrutinising the company's supplies of slivered onions and beef patties as they try to determine the cause of the outbreak, the company said.

The US Department of Agriculture said late on Wednesday that the onions used were the likely source of the illness, though one of its state partners is testing samples of the beef for E. coli.

The E. coli O157:H7 strain that led to the McDonald's outbreak is the same as a strain linked to a 1993 incident at Jack in the Box that killed four children. McDonald's suppliers test their products frequently and did so in the date range the CDC gave for the outbreak, and none of them identified this E. coli strain, company spokespeople said.