Myroides odoratimimus necrotising fasciitis and recurrent bacteraemia in an immunosuppressed patient with chronic leg ulcers: an emerging pattern?

Introduction: A 58yr old with inflammatory arthritis and diabetes, taking biologics, methotrexate and prednisolone, presented unconscious, hypotensive in acute renal failure. She had chronic leg ulcers and blistering, necrotic skin on both legs. After resuscitation, empiric meropenem and clindamycin, and urgent surgical debridement of her legs, she spent 2 days on ITU. A rapid recovery followed with discharge home after 7 days.

Methods: Histological samples were consistent with necrotising fasciitis. Blood and tissue cultures grew a yellow pigmented, oxidase positive, Gram negative bacillus with a distinctive fruity smell. 16S PCR confirmed Myroides odoratimimus.

The patient was readmitted 3 months later with unhealed leg ulcers, sepsis and blistering cellulitis

Blood cultures again grew Myroidesspp.

She recovered with meropenem and avoided ITU admission.

Discussion: Review of laboratory isolates over 2 years revealed a previous fatal case of Myroides bacteraemia in an 87year old woman with leg ulcers and possible necrotising fasciitis

Two further isolates were recovered from community samples:

* A cat bite in a 55 year old woman with alcohol excess.

* A chronic diabetic foot infection in an 80year old man.

Neither patient was admitted to hospital.

A PubMed search for “Myroides “ yielded 107 results. Most detailed the wide environmental distribution, multiple antibiotic resistance, and biofilm forming ability of the genus - worrying attributes in organisms causing infection in immunosuppressed patients.

Eleven of the twenty-three clinical papers described SSTI in patients with diabetes, renal disease, cirrhosis or other immunosuppression, including 3 of the 4 reported bacteraemias. Our cases fit well with this pattern.