title: Multidrug-resistant Escherichia coli soft tissue infection investigated with bacterial whole genome sequencing.
abstract: A 45-year-old man with dilated cardiomyopathy presented with acute leg pain and erythema suggestive of necrotising fasciitis. Initial surgical exploration revealed no necrosis and treatment for a soft tissue infection was started. Blood and tissue cultures unexpectedly grew a Gram-negative bacillus, subsequently identified by an automated broth microdilution phenotyping system as an extended-spectrum β-lactamase producing Escherichia coli. The patient was treated with a 3-week course of antibiotics (ertapenem followed by ciprofloxacin) and debridement for small areas of necrosis, followed by skin grafting. The presence of E. coli triggered investigation of both host and pathogen. The patient was found to have previously undiagnosed liver disease, a risk factor for E. coli soft tissue infection. Whole genome sequencing of isolates from all specimens confirmed they were clonal, of sequence type ST131 and associated with a likely plasmid-associated AmpC (CMY-2), several other resistance genes and a number of virulence factors.
authors.affiliation: Department of Microbiology and Infectious Diseases, Oxford University Hospitals, Oxford, UK.
authors.forename: Ruaridh
authors.initials: R
authors.lastname: Buchanan
authors.affiliation: Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
authors.forename: Nicole
authors.initials: N
authors.lastname: Stoesser
authors.affiliation: Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
authors.forename: Derrick
authors.initials: D
authors.lastname: Crook
authors.affiliation: Department of Microbiology and Infectious Diseases, Oxford University Hospitals, Oxford, UK.
authors.forename: Ian C J W
authors.initials: IC
authors.lastname: Bowler
mesh_terms: D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use; D003937:Diagnosis, Differential; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D000077727:Ertapenem; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D005436:Floxacillin / Q000627:therapeutic use; D005500:Follow-Up Studies; D016680:Genome, Bacterial / Q000235:genetics*; D005839:Gentamicins / Q000627:therapeutic use; D006801:Humans; D008107:Liver Diseases / Q000150:complications; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D017422:Sequence Analysis, DNA / Q000379:methods; D018461:Soft Tissue Infections / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D013845:Thienamycins / Q000627:therapeutic use; D016896:Treatment Outcome; D014640:Vancomycin / Q000627:therapeutic use; D047090:beta-Lactams / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D013845:Thienamycins; D047090:beta-Lactams; D005436:Floxacillin; D002939:Ciprofloxacin; D014640:Vancomycin; D019980:Amoxicillin-Potassium Clavulanate Combination; D000077731:Meropenem; D000077727:Ertapenem