5-≥256 4 16 16 ≤0.25-≥256 2 4 6 Cefoxitin a ≤2-32 ≤2 8 5 ≤2-≥32 4 8 8 Cefotetan a ≤1-8 ≤1 ≤1 0 ≤1-≥32 ≤1 ≤1 2 Cefotaxime 32-≥128 ≥128 ≥128 100 ≤0.5-128 ≤0.5 ≤0.5 5 Protein Tyrosine Kinase inhibitor Ceftazidime ≤0.5-≥128 2 16 23 ≤0.5-128

≤0.5 ≤0.5 8 Cefepime ≤1-≥32 ≥32 ≥32 96 ≤1-4 ≤1 <1 1 Aztreonam 2-≥64 16 ≥64 96 ≤0.5-32 ≤0.5 ≤0.5 6 Imipenem ≤0.5-1 ≤0.5 ≤0.5 0 ≤0.5-2 ≤0.5 ≤0.5 0 Meropenem ≤0.5 ≤0.5 ≤0.5 0 ≤0.5 ≤0.5 ≤0.5 0 Gentamicin ≤0.5-≥256 1 32 19 0.5-≥256 64 256 96 Tobramycin 0.5-256 1 8 17 ≤0.25-256 8 32 89 Amikacin ≤0.5-8 2 4 0 1-8 2 4 0 Nalidixic acid a 1-≥256 ≥256 ≥256 89 1-≥256 ≥256 ≥256 98 Ciprofloxacin a ≤0.5-≥256 16 128 74 ≤0.25-≥256 32 128 93 Tetracycline a 0.5-≥256 256 256 80 ≤0.25-256 256 256 84 Doxycycline a ≤0.5-128 16 64 76 ≤0.25-128 32 64 79 Tigecycline b ≤0.5-1 ≤0.5 ≤0.5 0 ≤0.25-0.5 ≤0.25 ≤0.25 0 Trimethoprim-Sulfamethoxazole ≤0.5-≥32 ≥32/608 ≥32/608 67 ≤0.5-≥32 ≥32/608 GSK3326595 purchase ≥32/608 98 a CLSI 2011 breakpoints. b FDA breakpoints. All Ec-MRnoB were susceptible to AR-13324 supplier imipenem, meropenem, amikacin and tigecycline. Eight isolates in this collection were resistant to at least one extended-spectrum cephalosporin (ceftazidime) (Table 1). The most frequent phenotype of resistance observed among the selected Ec-MRnoB isolates included resistance to β-lactams (amoxicillin), aminoglycosides [gentamicin

alone or (more often) associated to tobramycin], quinolones (nalidixic acid alone or associated to ciprofloxacin), tetracyclines (tetracycline alone or associated to doxycycline) and trimethoprim-sulfamethoxazole, occurring in 50% of the studied isolates. All other possible combinations of co-resistances among the selected isolates represented no more than 5% of the isolates. Most Ec-ESBL were of phylogroup B1 (38%), Cell press followed by groups A (32%), D (22%) and B2 (8%).

In contrast, the most frequent phylogenetic group of Ec-MRnoB was D (46%), followed by groups A (25%), B2 (17%) and B1 (12%). The 100 Ec-ESBL isolates were grouped in 66 Rep-PCR patterns. In this group, only 2 Rep-PCR patterns included 5 or more isolates: patterns XXXI (n=6, phylogenetic group A) and XXII (n=5; B1). The remaining patterns contained 2 to 4 isolates (16 Rep-PCR patterns) or single isolates (48 Rep-PCR patterns). Lower clonal variability was noted among the Ec-MRnoB, which were grouped into 40 Rep-PCR patterns. Three patterns included 5 or more isolates: I-NB (n=18, phylogenetic group D), II-NB (n=14; B2) and XXIII-NB (n=8; D). Fifteen patterns included 2 to 4 isolates, and the remaining 22 patterns corresponded to single isolates. Comparison of Rep-PCR patterns corresponding to isolates of the two E. coli collections showed the presence of Ec-ESBL (5 Rep-PCR patterns corresponding to 11 isolates) and Ec-MRnoB (4 Rep-PCR patterns corresponding to 30 isolates) with the same pattern.