Yuuki Suzuki1, Toyotaka Sato2, Yukari Fukushima3, Chie Nakajima4, Yasuhiko Suzuki4, Satoshi Takahashi5, Shin-Ichi Yokota1. 1. Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan. 2. Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan. Electronic address: sato.t@sapmed.ac.jp. 3. Division of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan. 4. Division of Bioresources, Hokkaido University Research Center for Zoonosis Control, Sapporo, Japan; Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan. 5. Division of Laboratory Medicine, Sapporo Medical University Hospital, Sapporo, Japan; Department of Infection Control and Laboratory Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
Abstract
INTRODUCTION: Tazobactam-piperacillin (TZP) is a mixture of a broad-spectrum penicillin and an irreversible β-lactamase inhibitor. TZP is effective against Gram-negative bacteria that produce extended-spectrum β-lactamases, and it is used as a first-line or second-line drug to treat serious infections. METHODS: This study identified three TZP-resistant and two TZP-intermediate strains among 514 clinical isolates of Escherichia coli. RESULTS: These five isolates possessed one or more β-lactamase genes, blaTEM-1, blaCTX-M-2, blaCTX-M-14, and/or blaCMY-8. The expression levels of β-lactamase genes and acrAB genes in the strains were examined by using real-time reverse transcription PCR. The total enzymatic piperacillin-degrading activity in cells was determined. Two TZP-resistance mechanisms were identified: hyperproduction of TEM-1 in the two resistant strains; and simultaneous high production of β-lactamase and efflux pump AcrAB in the two TZP-intermediate isolates. The latter are an international high-risk clone O25b:H4-ST131-H30R. CONCLUSION: TZP resistance is still rare in clinical isolates of E. coli. However, resistance can develop on high production and/or combinations of known antimicrobial resistance mechanisms in different ways.
INTRODUCTION:Tazobactam-piperacillin (TZP) is a mixture of a broad-spectrum penicillin and an irreversible β-lactamase inhibitor. TZP is effective against Gram-negative bacteria that produce extended-spectrum β-lactamases, and it is used as a first-line or second-line drug to treat serious infections. METHODS: This study identified three TZP-resistant and two TZP-intermediate strains among 514 clinical isolates of Escherichia coli. RESULTS: These five isolates possessed one or more β-lactamase genes, blaTEM-1, blaCTX-M-2, blaCTX-M-14, and/or blaCMY-8. The expression levels of β-lactamase genes and acrAB genes in the strains were examined by using real-time reverse transcription PCR. The total enzymatic piperacillin-degrading activity in cells was determined. Two TZP-resistance mechanisms were identified: hyperproduction of TEM-1 in the two resistant strains; and simultaneous high production of β-lactamase and efflux pump AcrAB in the two TZP-intermediate isolates. The latter are an international high-risk clone O25b:H4-ST131-H30R. CONCLUSION:TZP resistance is still rare in clinical isolates of E. coli. However, resistance can develop on high production and/or combinations of known antimicrobial resistance mechanisms in different ways.
Authors: Thomas Edwards; Eva Heinz; Jon van Aartsen; Alex Howard; Paul Roberts; Caroline Corless; Alice J Fraser; Christopher T Williams; Issra Bulgasim; Luis E Cuevas; Christopher M Parry; Adam P Roberts; Emily R Adams; Jenifer Mason; Alasdair T M Hubbard Journal: Microb Genom Date: 2022-04