TABLE 3.

Galactomannan assay reactivity with antibiotic dilutions at achievable peak concentrations in serum and at a two-fold dilution above and at 2 dilutions below the peak

Concn (μg/ml) of the antibiotic in serumb	Indexa	Interpretation of the test
Piperacillin
600	0.241	Negative
	0.241	Negative
300b	0.213	Negative
	0.209	Negative
150	0.216	Negative
	0.193	Negative
75	0.216	Negative
	0.135	Negative
Piperacillin-tazobactam, lot A
600	0.378	Negative
	0.344	Negative
300b	0.309	Negative
	0.275	Negative
150	0.177	Negative
	0.218	Negative
75	0.240	Negative
	0.230	Negative
Piperacillin-tazobactam, lot B2
600	0.686	Positive
	0.698	Positive
300b	0.391	Negative
	0.405	Negative
150	0.252	Negative
	0.249	Negative
75	0.210	Negative
	0.208	Negative
Piperacillin-tazobactam, lot C3
600	2.505	Positive
	2.362	Positive
300b	1.450	Positive
	1.423	Positive
150	0.840	Positive
	0.788	Positive
75	0.509	Positive
	0.452	Negative
10	0.170	Negative
	0.170	Negative
5	0.212	Negative
	0.205	Negative

^aIndex values for each dilution are the test results for duplicate wells.

^bThe values at 300 μg/ml are the achievable peak levels in serum for the antibiotic indicated.