Fig. 3b.

Charts showing thermal stability measured for each antibiotic over time, as determined by bioassay. Results are expressed as means from triplicate experiments. Zone of inhibition (ZOI) indicates diameter of the zone of inhibition, in millimetres. Statistically significant variations of the ZOI relative to starting values are marked with an asterisk where appropriate. Antibiotic solutions were prepared and maintained at 37°C for 42 days (body temperature group). Of note, temocillin and aztreonam have been tested with E. coli NCTC 12241, and colistimethate with P. aeruginosa PAO1, whereas all other results are from inhibition of S. aureus NCTC 12973.