Antimicrobial susceptibilities of Proteus mirabilis: a longitudinal nationwide study from the Taiwan surveillance of antimicrobial resistance (TSAR) program

Table 1 Antimicrobial susceptibilities (%) of Proteus mirabilis by study year, 2002-2012

Antimicrobial agents^a	2002 (n = 176)	2004 (n = 186)	2006 (n = 205)	2008 (n = 219)	2010 (n = 185)	2012 (n = 186)	P ^b	total (n = 1157)
β-lactams:
Amoxicillin/CA^c	91.4	74.7	86.8	83.6	NT	NT		84.6
Ampicillin	33.3	32.3	31.7	39.3	NT	NT		34.3
Aztreonam_2009	99.4	99.5	98.5	100	100	99.5		99.5
Aztreonam	99.4	98.9	98.5	100	100	98.9		99.3
Cefazolin_2009	73.6	64.0	74.2	75.3	NT	NT		71.9 ^d
Cefazolin	0.6	0	2.4	0.5	NT	NT		0.9
Cefuroxime	92.5	83.3	85.9	88.6	NT	NT		87.5
Cefotaxime_2009	95.5	88.2	96.6	94.9	98.4	97.3		95.2
Cefotaxime	92.6	84.4	86.8	88.5	80	81.7	0.003	85.7
Ceftazidime_2009	100	99.5	99	98.2	97.8	95.7	0.001	98.4
Ceftazidime	100	98.4	98.1	96.4	95.6	95.2	0.001	97.2
Cefoxitin	96	94.1	94.6	95	NT	NT		94.9
Cefepime	97.2	91.4	97.6	99.1	100	98.9		97.4^e
Ertapenem_2009	NT	NT	NT	NT	100	100		100
Ertapenem	NT	NT	NT	NT	100	99.5		99.7
Imipenem_2009	100	100	99.5	99.5	100	100		99.8 ^d
Imipenem	34.7	16.1	56.6	43.4	92.4	67.2		51.7
Meropenem	NT	NT	NT	NT	100	100		100
Piperacillin	48.9	44.6	37.6	43.3	NT	NT		43.4
Non β-lactams:
Amikacin	92.6	88.2	89.8	90.4	90.3	88.7		90
Gentamicin	59.1	60.8	54.2	62.1	55.1	54.3		57.7
Ciprofloxacin	80.1	70.3	68.3	69.9	70.3	53.8	< 0.001	68.7
TMP/SMX (SXT)^c	35.8	33.3	29.8	37	36.8	31.7		34.1
ESBL prevalence	5.1	10.2	10.7	6.9	5.4	10.8		8.2
AmpC prevalence	0	3.8	2.9	5.0	9.2	7.0	< 0.001	4.7

^aSusceptibility results are based on the current CLSI breakpoints [19]. For agents with breakpoint revision in recent years, results of the 2009 CLSI criteria are also shown for comparison [25].
^bChi-square for trends. Only statistically significant results are shown.
^cAmox/CA, Amoxacillin/clavulanic acid; TMP/SMX (SXT), trimethoprim/sulfamethoxazole.
^dItalicized, significant difference (P < 0.001) in susceptibility rates using old and revised breakpoints.
^eCefepime results include 3.5 % (41 isolates) in the SDD (susceptible dose dependent) category.

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