Crab bite causing shewanella putrefaciens infection: Introduction to a possibly deadly and emerging threat

Shewanella species are gram-negative bacteria found in warm, temperate regions and are normal microflora of the marine environment1. Human infections are unusual and have a restricted geographic distribution. PRESENTATION: A 45 years old lady was bitten by a crab while preparing to cook it. She developed fever and swelling of the right thumb with hemoserous discharge and blackish discolouration.Upon examination, the thumb was erythematous and swollen with a hematoma filled blister formation over the dorsal aspect. Deblistering was done and fluid samples were sent for culture and sensitivity which later returned as Shewanella Putrefaciens. Empirically she was started on IV Augmentin. DISCUSSION: Most common clinical manifestation associated with Shewanella spp are superficial soft tissue infection(1). Other reported clinical features are primary and secondary bacteremia, hepatobiliary, bone, joint and CNS infection, endocarditis, eye, ear and respiratory infection(2). Antibiotics susceptibility includes aminoglycosides, 3(rd) and 4(th) generation cephalosporins, carbapenems and fluoroquinolones(1). About 79% of patients have underlying conditions such as diabetes mellitus, venous congestion and heart failure; they are immunocompromised, as is our patient(3). CONCLUSION: Proper handling of seafood during preparation should be encouraged as a simple bite may turn deadly. Initiation of antibiotics according to suspected organisms should be performed to prevent worsening of soft tissue infections. REFERENCES: 1. Diaz, J.H, Lopez, F.A Skin, Soft Tissue and Systemic Bacterial Infections Following Aquatic Injuries and Exposures. The American Journal of the Medical Sciences, 349(3), 269275. 2. Finkelstein,R, Oren,I. Soft Tissue Infections Caused by Marine Bacterial Pathogens: Epidemiology, Diagnosis, and Management. Current Infectious Disease Report (2011)13(5):470–477. 3. N. Vignier et al; Human Infection with Shewanella putrefaciens and S. algae: Report of 16 Cases in Martinique and Review of the Literature; Am. J. Trop. Med. Hyg., 89(1), 2013, pp. 151–156;