BACKGROUND: FosA10-producing Enterobacterales have an extremely low incidence in Europe. PATIENTS AND METHODS: In March 2024, an 83-year-old woman, hospitalized in the Modena Province, developed an infection with fosfomycin-resistant Escherichia coli. The patient was treated with piperacillin/tazobactam and, after 10 days, the clinical picture was resolved. Fosfomycin MIC was evaluated with the reference agar dilution method and the production of FosA enzymes by phenotypic testing. Genomic characterization was assessed using long-read sequencing technology on the Sequel I platform. RESULTS: An E. coli isolate (FO_2) was collected from both blood and urine samples and showed high-level resistance to fosfomycin (MIC > 128 mg/L). The resistance to fosfomycin was ascribed to the production of FosA-like enzymes by phenotypic testing. The genomic analysis pointed to a FosA10-producing E. coli ST69. The fosA10 gene was carried by a highly conjugative IncB/O/K/Z plasmid that showed relevant similarities with other globally circulating plasmids. CONCLUSIONS: The acquisition of rare fosA-like genes in clinically relevant clones is concerning and the dissemination of FosA-producing E. coli should be continuously monitored.

1 R C C S Policlinico S Matteo SC Microbiology and Virology Department of Diagnostic and Laboratory Medicine Pavia Italy

Biomedical Center Faculty of Medicine Charles University Pilsen Czechia

Clinical Microbiology AUSL Modena 41125 Modena Italy

Department of Microbiology Faculty of Medicine University Hospital in Pilsen Charles University Pilsen Czechia

Infectious Diseases Clinic AOU Policlinico di Modena Modena Italy

S C C D P Department Microbiology and Clinical Microbiology Unit University of Pavia Pavia Italy

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Zhou  Y, Zhou  Z, Zheng  L  et al.  Urinary tract infections caused by uropathogenic PubMed DOI PMC

Doumith  M, Day  M, Ciesielczuk  H  et al.  Rapid identification of major PubMed DOI PMC

Lara  FBM, Nery  DR, de Oliveira  PM  et al.  Virulence markers and phylogenetic analysis of PubMed DOI PMC

Chen  L, Ou  B, Zhang  M  et al.  Coexistence of fosfomycin resistance determinant PubMed DOI

Ho  PL, Chan  J, Lo  WU  et al.  Prevalence and molecular epidemiology of plasmid-mediated fosfomycin resistance genes among blood and urinary PubMed DOI

Ho  PL, Chan  J, Lo  WU  et al.  Plasmid-mediated fosfomycin resistance in PubMed DOI

Hou  J, Huang  X, Deng  Y  et al.  Dissemination of the fosfomycin resistance gene PubMed DOI PMC

Hou  J, Yang  X, Zeng  Z  et al.  Detection of the plasmid-encoded fosfomycin resistance gene PubMed DOI

Lee  SY, Park  YJ, Yu  JK  et al.  Prevalence of acquired fosfomycin resistance among extended-spectrum β-lactamase-producing PubMed DOI

Lin  D, Chen  S. First detection of conjugative plasmid-borne fosfomycin resistance gene PubMed DOI PMC

Mattioni Marchetti  V, Hrabak  J, Bitar  I. Fosfomycin resistance mechanisms in Enterobacterales: an increasing threat. Front Cell Infect Microbiol  2023; 13: 1178547. 10.3389/fcimb.2023.1178547 PubMed DOI PMC

Huang  Y, Lin  Q, Zhou  Q  et al.  Identification of PubMed DOI PMC

Mattioni Marchetti  V, Kraftova  L, Finianos  M  et al.  Polyclonal spread of fosfomycin resistance among carbapenemase-producing members of the Enterobacterales in the Czech Republic. Microbiol Spectr  2023; 11: e0009523. 10.1128/spectrum.00095-23 PubMed DOI PMC

Zurfluh  K, Treier  A, Schmitt  K  et al.  Mobile fosfomycin resistance genes in Enterobacteriaceae—an increasing threat. MicrobiologyOpen  2020; 9: e1135. 10.1002/mbo3.1135 PubMed DOI PMC

Galindo-Méndez  M, Navarrete-Salazar  H, Baltazar-Jiménez  F  et al.  Emergence of fosfomycin resistance by plasmid-mediated PubMed DOI PMC

Hammad  AM, Hoffmann  M, Gonzalez-Escalona  N  et al.  Genomic features of colistin resistant PubMed DOI

Giacobbe  DR, Del Bono  V, Coppo  E  et al.  Emergence of a KPC-3-producing PubMed DOI

Hameed  MF, Chen  Y, Bilal  H  et al.  The co-occurrence of PubMed DOI

Garcia-Fulgueiras  V, Caiata  L, Bado  I  et al.  Antibiotic susceptibility and fosfomycin resistance characterization in a cohort of children older than 6 years of age with urinary tract infection. Rev Argent Microbiol  2022; 54: 120–4. 10.1016/j.ram.2021.04.002 PubMed DOI

Aziz  RK, Bartels  D, Best  AA  et al.  The RAST server: rapid annotations using subsystems technology. BMC Genomics  2008; 9: 75. 10.1186/1471-2164-9-75 PubMed DOI PMC

Dyer  NP, Päuker  B, Baxter  L  et al.  EnteroBase in 2025: exploring the genomic epidemiology of bacterial pathogens. Nucleic Acids Res  2025; 53: D757–62. 10.1093/nar/gkae902 PubMed DOI PMC

Alikhan  NF, Petty  NK, Ben Zakour  NL  et al.  BLAST Ring Image Generator (BRIG): simple prokaryote genome comparisons. BMC Genomics  2011; 12: 402. 10.1186/1471-2164-12-402 PubMed DOI PMC

Price  MN, Dehal  PS, Arkin  AP. FastTree 2 – approximately maximum-likelihood trees for large alignments. PLoS One  2010; 5: e9490. 10.1371/journal.pone.0009490 PubMed DOI PMC

Carattoli  A, Bertini  A, Villa  L  et al.  Identification of plasmids by PCR-based replicon typing. J Microbiol Methods  2005; 63: 219–28. 10.1016/j.mimet.2005.03.018 PubMed DOI

Letunic  I, Bork  P. Interactive Tree of Life (iTOL) v6: recent updates to the phylogenetic tree display and annotation tool. Nucleic Acids Res  2024; 52: W78–82. 10.1093/nar/gkae268 PubMed DOI PMC

Chudejova  K, Caltagirone  MS, Mattioni Marchetti  V  et al.  FosA8-producing PubMed DOI PMC

Novais  Â, Vuotto  C, Pires  J  et al.  Diversity and biofilm-production ability among isolates of PubMed DOI PMC

Behzadi  P, Najafi  A, Behzadi  E  et al.  Microarray long oligo probe designing for PubMed DOI PMC

Khonsari  MS, Behzadi  P, Foroohi  F. The prevalence of type 3 fimbriae in uropathogenic DOI

Mattioni Marchetti  V, Bitar  I, Piazza  A  et al.  Genomic insight of VIM-harboring IncA plasmid from a clinical ST69 PubMed DOI PMC

Soliman  AM, Ramadan  H, Sadek  M  et al.  Draft genome sequence of a PubMed DOI

Sghaier  S, Abbassi  MS, Pascual  A  et al.  Extended-spectrum β-lactamase-producing Enterobacteriaceae from animal origin and wastewater in Tunisia: first detection of O25b-B2 PubMed DOI

Benlabidi  S, Raddaoui  A, Lengliz  S  et al.  Occurrence of high-risk clonal lineages ST58, ST69, ST224, and ST410 among extended-spectrum β-lactamase-producing PubMed DOI PMC

Wang  YP, Chen  YH, Hung  IC  et al.  Transporter genes and PubMed DOI PMC

Zhou  Y, Ai  W, Cao  Y  et al.  The co-occurrence of NDM-5, MCR-1, and FosA3-encoding plasmids contributed to the generation of extensively drug-resistant PubMed DOI PMC

Huang  L, Hu  H, Xu  C  et al.  Characterization of NDM-5-producing PubMed DOI PMC

Woksepp  H, Karlsson  K, Börjesson  S  et al.  Dissemination of carbapenemase-producing Enterobacterales through wastewater and gulls at a wastewater treatment plant in Sweden. Sci Total Environ  2023; 886: 163997. 10.1016/j.scitotenv.2023.163997 PubMed DOI

Zhao  QY, Zhu  JH, Cai  RM  et al.  IS PubMed DOI PMC