. 2011 Jan 3;55(3):1279–1281. doi: 10.1128/AAC.00979-10

TABLE 1.

Antimicrobial susceptibility of 48 Brucella melitensis isolates^a

Antibiotic	2000-2001			2005-2006			P^b	Breakpoint^c for susceptibility (mg/liter)
Antibiotic	MIC₅₀	MIC₉₀	Range	MIC₅₀	MIC₉₀	Range	P^b	Breakpoint^c for susceptibility (mg/liter)
Doxycycline	0.19	0.38	0.064-0.5	0.38	0.38	0.032-0.38	0.022	≤2
Azithromycin	0.25	0.5	0.064-0.5	0.25	0.50	0.064-0.50	0.310	≤4
Gentamicin	0.125	0.25	0.064-0.250	0.125	0.226	0.032-0.25	0.029	ND^d
Rifampin	0.50	0.75	0.380-1.0	0.38	0.50	0.19-0.50	<0.0001	≤1
Ciprofloxacin	0.125	0.214	0.064-0.250	0.125	0.25	0.094-0.25	0.013	≤1
Trimethoprim- sulfamethoxazole	0.064	0.151	0.012-0.64	0.032	0.094	0.016-0.125	0.134	≤0.5

Isolates were from the Centro Médico Naval and Hospital Arzobispo Loayza (January 2000 to April 2001) and Hospital Nacional Daniel Alcides Carrión (September 2005 to May 2006). All MICs are in mg/liter.

P values reflect the comparison between MIC₅₀ values over the two time periods (or MIC₉₀, in the case of doxycycline).

Standard breakpoints are from CLSI guidelines for slowly growing bacteria (Haemophilus spp.) (4).

ND, not defined by CLSI standards.