Antimicrobial susceptibility trends among gram-positive and -negative clinical isolates collected between 2005 and 2012 in Mexico: results from the Tigecycline Evaluation and Surveillance Trial

Table 5 Rates of resistant phenotypes collected in Mexico, T.E.S.T. 2005–2012

Pathogen	2005–2007		2008–2012		2005–2012
Pathogen	N	n (%)	N	n (%)	N	n (%)
Gram-positive
E. faecalis, vancomycin-R	142	0 (0.0)	332	2 (0.6)	474	2 (0.4)
E. faecium, vancomycin-R	42	12 (28.6)	94	18 (19.1)	136	30 (22.1)
S. aureus, methicillin-R	294	112 (38.1)	728	349 (47.9)	1022	461 (45.1)
Gram-negative
E. coli, ESBL-positive	333	134 (40.2)	863	333 (38.6)	1196	467 (39.0)
K. oxytoca, ESBL-positive	45	7 (15.6)	91	14 (15.4)	136	21 (15.4)
K. pneumoniae, ESBL-positive	236	59 (25.0)	616	154 (25.0)	852	213 (25.0)
H. influenzae, BL-positive	117	44 (37.6)	111	21 (18.9)^a	228	65 (28.5)
Acinetobacter spp., meropenem-R	96^b	17 (17.7)	324	107 (33.0)^a	453	124 (27.4)
Acinetobacter spp., MDR	129	33 (25.6)	324	161 (49.7)^a	453	194 (42.8)

BL β-lactamase, ESBL extended-spectrum β-lactamase, R resistant, MDR multidrug resistant
^aA statistically significant change in the percentage of resistant phenotype (p < 0.05 by the Fisher’s exact test) between 2005–2007 and 2008–2012
^bA total of 129 Acinetobacter spp. were collected between 2005 and 2007; however, only 96 were tested against meropenem

ISSN: 1476-0711