Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli

Abstract Background Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is a potential  public health threat through its spread into the environment. Cefmetazole (CMZ) and flomoxef (FMOX) are highly effective alternatives to meropenem (MEM) for the management of ESBL-producing E. coli in...

Full description

Saved in:
Bibliographic Details
Main Authors: Nami Hatayama, Yoshinori Sato, Rika Tahira, Toki Hori, Shigeru Tansho-Nagakawa, Yasuo Ono, Yusuke Yoshino
Format: Article
Language:English
Published: BMC 2025-07-01
Series:BMC Microbiology
Subjects:
Online Access:https://doi.org/10.1186/s12866-025-04088-z
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849402807838310400
author Nami Hatayama
Yoshinori Sato
Rika Tahira
Toki Hori
Shigeru Tansho-Nagakawa
Yasuo Ono
Yusuke Yoshino
author_facet Nami Hatayama
Yoshinori Sato
Rika Tahira
Toki Hori
Shigeru Tansho-Nagakawa
Yasuo Ono
Yusuke Yoshino
author_sort Nami Hatayama
collection DOAJ
description Abstract Background Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is a potential  public health threat through its spread into the environment. Cefmetazole (CMZ) and flomoxef (FMOX) are highly effective alternatives to meropenem (MEM) for the management of ESBL-producing E. coli infections. However, their antimicrobial effects on biofilms remain unclear. Therefore, this study aimed to elucidate the inhibitory and bactericidal effects of CMZ, FMOX, and MEM on the biofilms formed by ESBL-producing E. coli. Methods Three ESBL-producing E. coli clinical isolates with biofilm-forming abilities (strains F6, F11, and U3) were used in the present study. Biofilm formation and viability assay kits were used to assess the inhibitory and bactericidal effects of these antibiotics on the biofilm-dispersed and biofilm cells of these strains. Scanning electron microscopy (SEM) was used to acquire images of the biofilms treated with these antibiotics. Results CMZ and MEM exerted significant inhibitory effects on the growth of biofilm-dispersed cells of all three strains at 1 × minimum inhibitory concentration (MIC). FMOX also exerted significant inhibitory effects on the growth of biofilm-dispersed cells of F11 strain at 1 × MIC; however, it exerted inhibitory effects on the growth of biofilm-dispersed cells of strains F6 and U3 in a concentration-dependent manner. CMZ, FMOX, and MEM exerted different bactericidal effects on biofilm-dispersed cells. CMZ exerted significant inhibitory effects on biofilm formation in all strains at 1 × MIC, whereas MEM exerted significant inhibitory effects on biofilm formation in the F6 and F11 strains at 1 × MIC. FMOX induced biofilm formation in F6 and U3 strains at concentrations between 1 × and 4 × MICs. Notably, CMZ, FMOX, and MEM did not exert bactericidal effects on the biofilm cells of any strain. SEM analysis revealed the induction of bacterial filamentation in the presence of CMZ and FMOX and spheroplast formation in the presence of MEM at 1 × MIC. Conclusions CMZ, FMOX, and MEM exhibited varying antimicrobial effects against ESBL-producing E. coli biofilms. Notably, FMOX may increase biofilm formation by inducing strong morphological changes. CMZ and FMOX are effective alternatives to MEM for ESBL-producing E. coli infections; however, their use requires the consideration of biofilm formation.
format Article
id doaj-art-81283bde989c4e2ba2e0776322ccbc7e
institution Kabale University
issn 1471-2180
language English
publishDate 2025-07-01
publisher BMC
record_format Article
series BMC Microbiology
spelling doaj-art-81283bde989c4e2ba2e0776322ccbc7e2025-08-20T03:37:28ZengBMCBMC Microbiology1471-21802025-07-0125111310.1186/s12866-025-04088-zCefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coliNami Hatayama0Yoshinori Sato1Rika Tahira2Toki Hori3Shigeru Tansho-Nagakawa4Yasuo Ono5Yusuke Yoshino6Department of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineDepartment of Microbiology and Immunology, Teikyo University School of MedicineAbstract Background Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is a potential  public health threat through its spread into the environment. Cefmetazole (CMZ) and flomoxef (FMOX) are highly effective alternatives to meropenem (MEM) for the management of ESBL-producing E. coli infections. However, their antimicrobial effects on biofilms remain unclear. Therefore, this study aimed to elucidate the inhibitory and bactericidal effects of CMZ, FMOX, and MEM on the biofilms formed by ESBL-producing E. coli. Methods Three ESBL-producing E. coli clinical isolates with biofilm-forming abilities (strains F6, F11, and U3) were used in the present study. Biofilm formation and viability assay kits were used to assess the inhibitory and bactericidal effects of these antibiotics on the biofilm-dispersed and biofilm cells of these strains. Scanning electron microscopy (SEM) was used to acquire images of the biofilms treated with these antibiotics. Results CMZ and MEM exerted significant inhibitory effects on the growth of biofilm-dispersed cells of all three strains at 1 × minimum inhibitory concentration (MIC). FMOX also exerted significant inhibitory effects on the growth of biofilm-dispersed cells of F11 strain at 1 × MIC; however, it exerted inhibitory effects on the growth of biofilm-dispersed cells of strains F6 and U3 in a concentration-dependent manner. CMZ, FMOX, and MEM exerted different bactericidal effects on biofilm-dispersed cells. CMZ exerted significant inhibitory effects on biofilm formation in all strains at 1 × MIC, whereas MEM exerted significant inhibitory effects on biofilm formation in the F6 and F11 strains at 1 × MIC. FMOX induced biofilm formation in F6 and U3 strains at concentrations between 1 × and 4 × MICs. Notably, CMZ, FMOX, and MEM did not exert bactericidal effects on the biofilm cells of any strain. SEM analysis revealed the induction of bacterial filamentation in the presence of CMZ and FMOX and spheroplast formation in the presence of MEM at 1 × MIC. Conclusions CMZ, FMOX, and MEM exhibited varying antimicrobial effects against ESBL-producing E. coli biofilms. Notably, FMOX may increase biofilm formation by inducing strong morphological changes. CMZ and FMOX are effective alternatives to MEM for ESBL-producing E. coli infections; however, their use requires the consideration of biofilm formation.https://doi.org/10.1186/s12866-025-04088-zExtended-spectrum β-lactamase (ESBL)-producing Escherichia coliBiofilmsCefmetazoleFlomoxefMeropenemInhibitory and bactericidal effects of antibiotics
spellingShingle Nami Hatayama
Yoshinori Sato
Rika Tahira
Toki Hori
Shigeru Tansho-Nagakawa
Yasuo Ono
Yusuke Yoshino
Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
BMC Microbiology
Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli
Biofilms
Cefmetazole
Flomoxef
Meropenem
Inhibitory and bactericidal effects of antibiotics
title Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
title_full Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
title_fullStr Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
title_full_unstemmed Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
title_short Cefmetazole, flomoxef, and meropenem are effective against planktonic cells but not biofilms of extended-spectrum β-lactamase-producing Escherichia coli
title_sort cefmetazole flomoxef and meropenem are effective against planktonic cells but not biofilms of extended spectrum β lactamase producing escherichia coli
topic Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli
Biofilms
Cefmetazole
Flomoxef
Meropenem
Inhibitory and bactericidal effects of antibiotics
url https://doi.org/10.1186/s12866-025-04088-z
work_keys_str_mv AT namihatayama cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT yoshinorisato cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT rikatahira cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT tokihori cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT shigerutanshonagakawa cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT yasuoono cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli
AT yusukeyoshino cefmetazoleflomoxefandmeropenemareeffectiveagainstplanktoniccellsbutnotbiofilmsofextendedspectrumblactamaseproducingescherichiacoli