MICs are different for E coli in urine and blood for cefazolin. Urine isolates are 96% susceptible but blood are 53% susceptible. Special attention must be paid when prescribing these antibiotics for E coli outside of urine
Note
Cefazolin has different breakpoints for gram-negative urine isolates versus other body sites.
Just because an E. coli isolate is susceptible in the urine, does not mean it is susceptible in the blood; blood breakpoints must be applied to the isolate.
