Case Presentation:

A 75–year–old male with CAD, CHF, DM, CKD, and anemia presents to the ER for leg pain. He injured his left knee in a fall a day prior to presentation and in the ER was noted to have a fever of 102f. Two weeks prior to admission, he had consumed several raw oysters and he was receiving IV iron for his anemia. Labs revealed 19 x103/mL Leukocytes, 9.4g/dL Hemoglobin, 86K/mL platelets, INR of 2.9, and ESR of 33mm/hr. The patient appeared ill and was moaning in pain. He had scattered eccymoses over his bilateral lower extremities with prominent warmth and swelling of his left knee. The patient was admitted to the ICU with severe sepsis and required vasopressors. His blood cultures and knee aspirate both revealed Shewanella Algae. CT abdomen, abdominal US, and transthoracic echo were all negative for any infection. After cultures resulted, vancomycin was discontinued and piperacillin–tazobactam was continued. He had arthroscopic debridement once his coagulopathy, presumed from dabagatran toxicity, improved enough by day 6. Synovial fluid cultures taken at that time once again grew Shewanella. Blood cultures from admission were pan–sensitive but after 5 days of piperacillin–tazobactam, susceptibilities from the knee debridement revealed ampicillin and cefazolin resistance. Hemorrhagic and serous bullae arose on his distal affected leg, signifying a degree of dermal involvement. Ciprofloxacin was started and piperacillin–tazobactam was continued with slow and gradual clinical improvement.

Discussion:

Shewanella Algae is a gram negative, rod–shaped proteobacterium ubiquitous in nature but most commonly found in saltwater. Disease ranges from cellulitis, abscesses, and osteomyelitis to necrotizing fasciitis and septicemia. It is usually found in the immunocompromised but also occasionally in healthy individuals. Shewanella was first described in 1931 after being isolated from putrefied butter. It was initially termed Achromobacter putrefaciens before being classified in the pseudomonas family and subsequently the Vibro family. Shewanella was recognized as a novel species in 1992.

Conclusions:

While Shewanella Algae is rarely found in humans and most of the literature is found in case reports, it is important to acknowledge the significant associated morbidity and mortality. It is important to consider in an immunocompromised patient that presents with leg ulcers, faciitis, or septicemia and has recently ingested raw seafood. One case report involves necrotizing fasciitis and septicemia after raw seafood which mimicked vibrio vulnificus resulting in death. Acquired antibiotic resistance has also been reported with this organism as seen in our case. Two other case reports demonstrate acquired antibiotic resistance during treatment with piperacillin–tazobactam and imipenem. Hemorrhagic and serous bullae are a common feature with skin involvement. Both dermal and joint infections should be treated aggressively with debridement and antibiotics to avoid amputation.