In vitroefficacy of 16 antimicrobial drugs against a large collection of β‐lactamase‐producing isolates of extraintestinal pathogenicEscherichia colifrom dogs and cats. Issue 8 (August 2017)

• Record Type: Journal Article
• Authors: Shimizu, Takae; Harada, Kazuki; Tsuyuki, Yuzo; Kimura, Yui; Miyamoto, Tadashi; Hatoya, Shingo; Hikasa, Yoshiaki
• Is Part Of: Journal of medical microbiology. Volume 66:Issue 8(2017)
• Publication Date: 2017-08
• Subjects: extended‐spectrum β‐lactamases -- Escherichia coli -- companion animals -- antimicrobial treatment; Medical microbiology -- Periodicals; 616.9041
• DOI: 10.1099/jmm.0.000535
• Languages: English
• ISSNs: 0022-2615

Abstract

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.