@article{mbs:/content/journal/jmm/10.1099/jmm.0.000535, author = "Shimizu, Takae and Harada, Kazuki and Tsuyuki, Yuzo and Kimura, Yui and Miyamoto, Tadashi and Hatoya, Shingo and Hikasa, Yoshiaki", title = "In vitro efficacy of 16 antimicrobial drugs against a large collection of β-lactamase-producing isolates of extraintestinal pathogenic Escherichia coli from dogs and cats", journal= "Journal of Medical Microbiology", year = "2017", volume = "66", number = "8", pages = "1085-1091", doi = "https://doi.org/10.1099/jmm.0.000535", url = "https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000535", publisher = "Microbiology Society", issn = "1473-5644", type = "Journal Article", keywords = "Escherichia coli", keywords = "extended-spectrum β-lactamases", keywords = "antimicrobial treatment", keywords = "companion animals", abstract = " Purpose. The aim of this study was to assess the in vitro efficacy of candidate antimicrobials against extended-spectrum β-lactamase (ESBL)-producing isolates of extraintestinal pathogenic Escherichia coli (ExPEC) from companion animals. Methodology. A total of 90 ESBL-producing ExPEC isolates from dogs and cats were tested for susceptibility to 16 antimicrobials with the agar dilution method. We also identified the ESBLs and AmpC β-lactamases of these isolates with PCR and DNA sequencing. Results/Key findings. All isolates were susceptible to meropenem, tebipenem and amikacin (AMK), and various proportions were susceptible to latamoxef (LMX, 97.8 %), fosfomycin (FOM, 97.8 %), faropenem (FPM, 96.7 %), nitrofurantoin (NFT, 96.7 %), flomoxef (FMX, 93.3 %), piperacillin/tazobactam (PTZ, 92.2 %), cefmetazole (CMZ, 91.1 %), chloramphenicol (80.0 %), trimethoprim/sulfamethoxazole (64.4 %), amoxicillin/clavulanic acid (63.3 %), ceftibuten (60.0 %), tetracycline (52.2 %) and enrofloxacin (10.0 %). A genetic analysis showed that 83 of the 90 (92.2 %) isolates were positive for CTX-M-type genes: CTX-M-14 (n=26), CTX-M-27 (n=20), CTX-M-55 (n=17), CTX-M-15 (n=12), CTX-M-2 (n=5), CTX-M-24 (n=2), CTX-M-104 (n=2) and CTX-M-3 (n=1). Eight isolates also expressed AmpC β-lactamase phenotypes. Conclusion. This study demonstrates that the susceptibility rates to PTZ, CMZ, LMX, AMK, FOM, FPM, NFT and FMX were similar to those to carbapenems (>90 %), implying that these drugs are available alternatives to carbapenems for the treatment of companion animals infected with ExPEC-producing CTX-M-type ESBLs. Further in vivo studies of the effective use of these antimicrobials are required.", }