TABLE 2.

Performance of MALDI-TOF MS DOT-MGA for direct detection of carbapenem nonsusceptibility in Enterobacterales from positive blood cultures using evaluation with MALDI Biotyper scores^a

Processing method	Dilution	Values for 3-h incubation (%)			Values for 4-h incubation (%)b
		Validityc	Sensitivityd	Specificityd	Validity	Sensitivity	Specificity
Filtration/dilution	1:100	96.3	100	42.9	100	92.3	14.3
	1:1,000	96.3	91.7	71.4	100	84.6	64.3
	1:10,000	85.2	80.0	100	88.9	81.8	100
Dilution	1:100	100	92.3	71.4	96.3	100	46.2
	1:1,000	96.3	83.3	85.7	100	84.6	92.9
	1:10,000	92.6	63.6	100	92.6	90.9	100
Lysis/centrifugation		92.6	90.9	100	96.3	91.7	100
Differential centrifugation		92.6	90.9	92.9	96.3	83.3	100

^an = 27.

^bThe values in bold indicate the processing methods and incubation time which resulted in the best test performance.

^cValidity, percentage of tests with the growth control successfully detected.

^dCalculated for valid tests.