Comparison of an Automated System with Conventional Identification and Antimicrobial Susceptibility Testing

Table 1

Discordant results obtained for isolates by Phoenix as compared to Kirby-Bauer disk diffusion test.

Antimicrobial (𝑛)*	Organism	Phoenix AST	Disc diffusion	Interpretation
Erythromycin (1)	S. saprophyticus	Susceptible	Resistant	Very major error
Vancomycin (1)	Enterococcus spp.	Resistant	Susceptible	Major error
Linezolid (2)		Intermediate	Susceptible	Minor errors
Erythromycin (1)		Intermediate	Susceptible	Minor error
Nitrofurantoin (1)		Resistant	Susceptible	Major error
Piperacillin/tazobactam (3)	Escherichia coli	Sensitive	Resistant	Very major error
Cefepime (2)	Escherichia coli	Sensitive	Resistant	Very major error
		Resistant	Intermediate	Minor error
Nitrofurantoin (1)	Escherichia coli	Intermediate	Susceptible	Minor error
Amikacin (3)	Escherichia coli	Resistant	Susceptible	Major error
		Susceptible	Intermediate	Minor error
	Proteus mirabilis	Resistant	Susceptible	Major error
Ciprofloxacin (2)	Enterobacter cloacae	Resistant	Intermediate	Minor error
	Proteus mirabilis	Resistant	Susceptible	Major error
Ceftriaxone (1)	Morganella morganii	Resistant	Intermediate	Minor error
Imipenem (1)	Acinetobacter lowffii	Resistant	Intermediate	Minor error
Ceftazidime (1)	Proteus mirabilis	Resistant	Susceptible	Major error

∗(𝑛): Total number of discordant results.