More than 6,000 deaths a year could be caused by a 30% fall in the effectiveness of antibiotics in the US, a report in The Lancet suggests.
It said most of the extra deaths would happen in patients having colorectal surgery, blood cancer chemotherapy and hip replacements.
UK experts said the study confirmed their fears that antibiotic resistance would affect routine surgery.
England's chief medical officer has called the issue a "ticking time bomb".
In this report, a team of scientists from a number of different American institutions estimated that as many as half of all bacteria that cause infections after surgery are resistant to antibiotics in the US.
They also estimated that one in four infections treated with antibiotics after chemotherapy treatment was now drug-resistant.
http://www.bbc.co.uk/news/health-34541253