Public areas including baby changing rooms, pedestrian crossings and hospital receptions are "reservoirs" for antibiotic-resistant bacteria, scientists say.
Researchers from the University of East London swabbed commonly touched surfaces in the east and west parts of the capital to compare levels of antibiotic-resistant staphylococci, a group of bacteria known to cause infections in humans.
They found disturbing levels of multi-drug-resistant bacteria on door handles, armrests and toilet seats in public areas such as London Underground stations and shopping centres, and public areas in two hospitals, such as receptions, public washrooms, corridors and lifts.
Cash and ticket machines, escalator rails and soap dispensers were also swabbed.
A total of 600 staphylococci isolates were recovered from general public settings and hospital public areas - 224 in east London and 376 in the west.
Of these, 281 (46.83%) showed resistance to two or more antibiotics, mainly to penicillin (80.42%), followed by fusidic acid (72.4%) and erythromycin (54.45%).
The findings, published in the Scientific Reports journal, show that 96 of the isolates were resistant to at least four antibiotics.
A higher proportion of multi-drug-resistant bacteria was found in public areas within hospitals (49.5%) compared with non-hospital public settings (40.66%), and in samples collected from east London (56.7%) compared with the west (49.96%).
The authors say these findings could reflect increased antibiotic use within hospitals and greater population density in east London.