LONDON — Bacteria resistant to antibiotics have now spread to every part of the world and might lead to a future where minor infections could kill, according to a report published Wednesday by the World Health Organization.

In its first global survey of the resistance problem, WHO said it found very high rates of drug-resistant E. coli bacteria. The agency noted there are many countries where treatment for the bug is useless in more than half of patients.

Unless there is urgent action, “the world is headed for a post-antibiotic era in which common infections and minor injuries which have been treatable for decades can once again kill,” Dr. Keiji Fukuda, one of the agency’s assistant director-generals, warned in a release.