Table 3.

Colistin susceptibility testing policies and confirmation of submitted isolates.

Used test result for isolate selection	Num. of labs	COLR-EK				COLS-EK
		Colistin susceptibility testing methoda	Submitted	Confirmed	%	Colistin susceptibility testing methoda	Submitted	Confirmed	%
Screening test	15	Automatedb	106	61	57.5%	Automatedc	80	61	76.3%
Confirmation test	7	BMD/Etest	13	11	84.6%	Automated	12	11	91.7%
Total	22		119	72	60.5%		92	72	78.3%

Of note: This tabe also includes isolates that are rejected based on other reasons than an incorrect colistin MIC.

^aUnknown method for the five laboratories with no submitted isolates.

^bAlso two submitted isolates with disk diffusion and two isolates with an Etest.

^cAlso one submitted isolate with disk diffusion.

BMD broth microdilution, COLR-EK colistin-resistant E. coli or K. pneumoniae, COLS-EK colistin-susceptible E. coli or K. pneumoniae.