Antifungal Susceptibility of 205 Candida spp. Isolated Primarily during Invasive Candidiasis and Comparison of the Vitek 2 System with the CLSI Broth Microdilution and Etest Methods

N. Bourgeois; L. Dehandschoewercker; S. Bertout; P.-J. Bousquet; P. Rispail; L. Lachaud

doi:10.1128/JCM.01096-09

DOI: 10.1128/JCM.01096-09

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Tables

TABLE 1.

Fluconazole and voriconazole MIC₅₀s and MIC₉₀s obtained with VK2, CLSI (24 h and 48 h), and Etest (24 h and 48 h)

Candida sp. (no. of isolates), azole, and method	24 h			48 h			EA^a (%)
Candida sp. (no. of isolates), azole, and method	MIC range	MIC₅₀	MIC₉₀	MIC range	MIC₅₀	MIC₉₀	EA^a (%)
C. albicans (84)
Fluconazole
VK2	≤1-≥64^d	≤1	≤1
CLSI	<0.125-64	0.125	0.5	<0.125->64	0.5	2	98.8
Etest	0.094-128	0.25	0.38	0.094->256	0.625	2	89.3
Voriconazole
VK2	≤0.12-0.5	≤0.12	≤0.12
CLSI	<0.03-1	0.03	0.125	<0.03-2	0.03	0.125	100
Etest	0.003-1	0.008	0.023	0.002-2	0.02	0.064	98.8
C. parapsilosis (22)
Fluconazole
VK2	≤1	≤1	≤1
CLSI	<0.125-8	0.125	0.5	<0.125-8	0.25	0.5	95.4
Etest	0.064-0.5	0.315	0.38	0.064-8	1	1.5	90.9
Voriconazole
VK2	≤0.12	≤0.12	≤0.12
CLSI	<0.03-0.25	<0.03	<0.03	<0.03-0.25	<0.03	0.03	100
Etest	0.004-0.047	0.012	0.023	0.006-0.19	0.032	0.064	100
C. tropicalis (17)
Fluconazole
VK2	≤1-2	≤1	2
CLSI	<0.125-2	0.25	0.5	0.125-2	0.5	2	100
Etest	0.5-2	1.5	1.5	0.38-6	1.5	3	64.7
Voriconazole
VK2	≤0.12	≤0.12	≤0.12
CLSI	<0.03-0.06	0.03	0.06	0.03-0.25	0.06	0.125	100
Etest	0.016-0.094	0.047	0.094	0.012-0.25	0.094	0.19	100
Other Candida spp. (5)^c
Fluconazole
VK2	≤1-2	≤1	≤1
CLSI	<0.125-0.5	0.125	0.125	<0.125-4	0.125	0.125	100
Etest	0.064-3	0.75	0.75	0.064-3	0.75	0.75	100
Voriconazole
VK2	≤0.12-≤0.12	≤0.12	≤0.12
CLSI	<0.03-<0.03	<0.03	<0.03	<0.03-<0.03	<0.003	<0.003	100
Etest	0.004-0.094	0.023	0.023	0.004-0.094	0.023	0.023	100
C. glabrata (56)
Fluconazole
VK2	≤1-≥64	8	32
CLSI	<0.125-64	2	8	0.125->64	6	16	94.6
Etest	0.094->256	7	16	0.094->256	>256	>256	25
Voriconazole
VK2	≤0.12-≥8	≤0.12	2
CLSI	<0.03-8	0.125	0.5	0.03-8	0.125	2	89.3
Etest	0.016-8	0.125	1.5	0.032->32	1.5	32	32.1
C. inconspicua (5), C. norvegensis (2)
Fluconazole
VK2	4-≥64	16	16
CLSI	<0.125-16	<0.125	<0.125	2-32	16	16	100
Etest	8-24	10	10	24->256	>256	>256	85.7
Voriconazole
VK2	≤0.12-0.25	≤0.12	≤0.12
CLSI	<0.03-0.5	<0.03	<0.03	0.03-0.5	0.25	0.25	100
Etest	0.19-2	0.19	0.19	0.19-2	0.19	0.19	85.7
C. krusei (14)
Fluconazole
VK2	4-32	16	32				100/92.8^b
CLSI	0.25-64	16	32	8-64	32	64	100^b
Etest				32->256	>256	>256
Voriconazole
VK2	≤0.12-0.25	≤0.12	0.25
CLSI	0.03-0.5	0.25	0.5	0.25-1	0.5	1	92.8
Etest	0.19-0.5	0.25	0.25	0.064-1.5	0.25	1.5	64.3

↵ a EA between VK2 and the two other methods at 48 h.
↵ b EA calculated with Vitek 2 expert software interpretive values.
↵ c C. lusitaniae (n = 2), C. guilliermondii (n = 1), C. kefyr (n = 1), and C. dubliniensis (n = 1).
↵ d MICs are in micrograms per milliliter.

TABLE 2.

Fluconazole and voriconazole susceptibilities of 205 Candida sp. isolates, CAs, and errors between VK2 and CLSI/Etest methods at 24 and 48 h

Species (no. of isolates), azole, and method	% of isolates (24 h/48 h)^a that were:			% CA with VK2 (24 h/48 h)^a	No. of VK2 errors (24 h/48 h)^a
Species (no. of isolates), azole, and method	Susceptible	SDD	Resistant	% CA with VK2 (24 h/48 h)^a	VME	ME	mE
C. albicans (84)
Fluconazole
VK2	98.8	0	1.2
CLSI	98.8	0	1.2	100	0	0	0
Etest	98.8	0	1.2	100	0	0	0
Voriconazole
VK2	100	0	0
CLSI	100/98.8	0/1.2	0	100/98.8	0	0	1
Etest	100/98.8	0/1.2	0	100/98.8	0	0	1
C. parapsilosis (22), C. tropicalis (17), other spp. (5)^b
Fluconazole + voriconazole
VK2	100	0	0
CLSI	100	0	0	100	0	0	0
Etest	100	0	0	100	0	0	0
C. glabrata (56)
Fluconazole
VK2	75	16.1	8.9
CLSI	80.3	14.3	5.4	78.6	0	1	11
Etest	71.5/12.5	16/23.2	12.5/64.3	77.3/23.2	1/23	1/0	12/20
Voriconazole
VK2	87.5	5.4	7.1
CLSI	89.3/85.7	7.2/10.7	3.5/3.6	89.3/87.5	0	0	4/5
Etest	89.3/48.2	7.2/10.7	3.5/41.1	89.2/51.8	0/20	1/0	5/7
C. inconspicua (5), C. norvegensis (2)
Fluconazole
VK2	42.85	42.85	14.3
CLSI	28.6	71.4	0	71.4	0	0	1/2
Etest	28.6/0	71.4/28.6	0/71.4	75/14.3	0/1	0	1/5
Voriconazole
VK2	100	0	0
CLSI	100	0	0	100	0	0	0
Etest	100/85.7	0/14.3	0	100/85.7	0	0	0/1
C. krusei (14)
Fluconazole
VK2^c	0	0	100
CLSI	35.7/7.1	57.1/64.3	7.1/28.6	7.1/28.6	0	5/1	8/9
Etest	0	7.1	92.9	92.9	0	0	1
Voriconazole
VK2	100	0	0
CLSI	100	0	0	100	0	0	0
Etest	100/85.7	0/14.3	0	100/85.7	0	0	2

↵ a Interpretative results obtained at 48 h if different from results at 24 h for CLSI and Etest methods only.
↵ b Two strains of C. lusitaniae, one strain of C. guilliermondii, one strain of C. kefyr, and one strain of C. dubliniensis.
↵ c Interpretative values and errors based on Vitek 2 expert software expertise.

TABLE 3.

Amphotericin B susceptibilities of the 205 Candida sp. isolates used in this study

Species (no. of isolates) and method	% of isolates (48 h) with MIC (mg/liter) of:		24 h			48 h			EA^a (%)
Species (no. of isolates) and method	≤1	>1	MIC range	MIC₅₀	MIC₉₀	MIC range	MIC₅₀	MIC₉₀	EA^a (%)
C. albicans (84)
VK2	100		≤0.25-1^c	0.5	1
CLSI	98.8	1.2	0.125-1	0.5	0.5	0.25-2	1	1	98.8
Etest	100		0.094-0.38	0.094	0.19	0.016-0.5	0.125	0.25	29.8
C. parapsilosis (22)
VK2	100		≤0.25-1	0.5	0.5
CLSI	81.8	18.2	0.125-0.5	0.25	0.5	0.5-2	1	2	86.4
Etest	100		0.094-0.5	0.125	0.25	0.064-1	0.38	0.75	63.6
C. tropicalis (17)
VK2	100		≤0.25-0.5	0.5	0.5
CLSI	100		0.5-1	0.25	1	0.5-2	1	2	100
Etest	100		0.047-0.25	0.125	0.19	0.032-0.75	0.25	0.5	70.6
Other Candida spp. (5)^b
VK2	100		≤0.25-0.5	0.5	0.5
CLSI	100		0.06-1	0.5	0.5	0.25-1	0.5	0.5	100
Etest	100					0.047-0.38	0.25	0.25	100
C. glabrata (56)
VK2	94.6	5.4	≤0.25-8	0.5	1
CLSI	89.3	10.7	0.125-2	0.5	1	0.25-2	1	1	98.2
Etest	98.2	1.8	0.016-1	0.25	0.5	0.023->32	0.38	0.75	73.2
C. inconspicua (5), C. norvegensis (2)
VK2	100		≤0.25-1	≤0.25	≤0.25
CLSI	100		0.03-1	0.125	0.125	0.25-1	0.25	0.25	100
Etest	100					0.016-0.75	0.064	0.064	100
C. krusei (14)
VK2	92.9	7.1	0.5-2	0.5	1
CLSI	71.4	28.6	1-2	1	2	0.25-2	1	2	100
Etest	85.7	14.3	0.094-1	0.75	0.75	0.19-2	0.875	2	78.6

↵ a EA between VK2 and the two other methods at 48 h.
↵ b C. lusitaniae (n = 2), C. guilliermondii (n = 1), C. kefyr (n = 1), and C. dubliniensis (n = 1).
↵ c MICs are in micrograms per milliliter.