Unusual “Flesh-Eating” Strains of Escherichia coli

Abstract

e Monomicrobial necrotizing fasciitis (type II) is typically caused by group A streptococcus alone or in combination with Staphylococcus aureus. Escherichia coli has been isolated from polymicrobial or Fournier's gangrene but has rarely been reported in monomicrobial necrotizing fasciitis. We describe the clinical characteristics and outcomes of seven cases of monomicrobial E. coli necrotizing fasciitis and/or severe soft tissue infection diagnosed at a single institution during an 18-month period. Four isolates from three patients and two isolates from two patients with type I polymicrobial severe soft tissue infection (controls) were assayed by the randomly amplified polymorphic DNA (RAPD) analysis for fingerprinting and PCR amplification of primers in order to detect cytotoxic necrotizing factor 1 and 2 (cnf1 and cnf2) genes. All patients had some type of immune suppression. The limb was the most commonly involved organ. In all cases, E. coli was isolated as a monomicrobial pathogen from blood, fascia, or both. All patients died during hospitalization, three within the first 48 h. The RAPD amplification assay showed a high degree of genetic diversity among the "flesh-eating" strains and controls. The cnf1 toxin gene was identified in two out of three cases, but not in the controls. cnf2 was not detected in any of the patients. E. coli may be responsible for life-threatening necrotizing fasciitis. Further research is needed to reveal relevant risk factors, reservoirs, and modes of transmission of cnf1 E. coli.

Draft Genome Sequence of a Necrotoxigenic Escherichia coli Isolate

“…It is usually caused by Streptococcus pyogenes ( 8 , 9 ), sometimes Staphylococcus aureus ( 10 ) or by a mixture of microorganisms including Streptococcus , S. aureus , Enterobacteriaceae , and some anaerobes ( 11 , 12 ). On rare occasions, necrotoxigenic E. coli was identified as the etiologic agent in chronically ill patients ( 13 – 20 ) or infants following surgery ( 21 , 22 ). Recently, we reported a lethal case of very rapidly evolving necrotizing fasciitis.…”

Necrotising fasciitis withEscherichia coliin a newborn infant after abdominal surgery

“…Documented Escherichia coli NF is less common, with almost all cases being fatal in the adult population 3. One neonatal case has been reported and this also describes a fatality 4…”

Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen

“…12 Recently, we reported several cases of E. coli monomicrobial NF from our hospital. 13 The aims of this study were to document the causative pathogens of monomicrobial NF in our hospital for the period 2002 to 2012 and to compare Gram-negative with Grampositive infections.…”