Case Report: Disseminated Shewanella algae Infection with Meningoencephalitis in a Traveler Secondary to Marine Injury in Madagascar

A Rare Cause of Empyema and Bacteremia Due to Shewanella Species in Alcoholic Cirrhosis Patients: A Case Report and Comprehensive Review of Literature

BACKGROUND Shewanella spp. are gram-negative facultative anaerobic, oxidase-positive, motile bacilli that are ubiquitous but commonly occur in seawater and can cause opportunistic infection. Reports on the risk factors for Shewanella infection, its severity, antibiotic susceptibility, and prognosis are limited. This report is of a 78-year-old man with alcoholic cirrhosis presenting with bacteremia and empyema due to infection with Shewanella spp. CASE REPORT A 78-year-old man with alcoholic cirrhosis (Child-Pugh B) presented to our emergency room with a high fever. He had eaten raw fish one week prior to admission. Chest computed tomography showed a right unilateral pleural effusion, and he was hospitalized with suspected empyema. Shewanella spp. was detected in the pleural effusion and blood cultures. We initiated piperacillin/tazobactam and vancomycin empirically and switched to ceftriaxone; the effusion was successfully treated using antibiotics and pleural drainage. However, on hospitalization day 53, the patient died of aspiration pneumonia. In our literature review, we extracted 125 reported cases (including our case) and found that men were disproportionately affected (81%); median age was 61.6 (56-75) years; underlying diseases included hepatobiliary disease (33%), malignancy (25%), and cardiac disease (24%); Shewanella spp. infection sites were skin and soft tissue (35%), respiratory system (18%), and hepatobiliary system (11%); and management included antibiotics (100%), drainage (16%), and debridement (16%). The survival rate was 74% with antibiotics alone. CONCLUSIONS Our case highlights that clinicians should recognize Shewanella spp. as a cause of empyema and bacteremia in patients with liver cirrhosis, and that microbiological diagnosis with antibiotic sensitivity testing and treatment should be undertaken urgently to prevent fatal sepsis.

Shewanella infection in humans: Epidemiology, clinical features and pathogenicity

The genus Shewanella consists of Gram-negative proteobacteria that are ubiquitously distributed in environment. As the members of this genus have rapidly increased within the past decade, several species have become emerging pathogens worldwide, attracting the attention of the medical community. These species are also associated with severe community- and hospital-acquired infections. Patients infected with Shewanella spp. had experiences of occupational or recreational exposure; meanwhile, the process of infection is complex and the pathogenicity is influenced by a variety of factors. Here, an exhaustive internet-based literature search was carried out in PUBMED using terms “Achromobacter putrefaciens,” “Pseudomonas putrefaciens,” “Alteromonas putrefaciens” and “Shewanella” to search literatures published between 1978 and June 2022. We provided a comprehensive review on the epidemiology, clinical features and pathogenicity of Shewanella, which will contribute a better understanding of its clinical aetiology, and facilitate the timely diagnosis and effective treatment of Shewanella infection for clinicians and public health professionals.

Surgical Site Infection by Shewanella algae After Major Surgery in a Patient With Colorectal Cancer: Case Report

Surgical site infections are a common complication in the management of patients with solid cancer tumors in cytotoxic chemotherapy. The antibiotic combination chosen depends on the neoadjuvant therapy used and the anatomical site and extent of the surgery. In this brief report, we describe a surgical site infection caused by an unusual microorganism and a succinct review of the pathogen's behavior.

Waterborne Infections in Reunion Island, 2010-2017

Gram-negative bacilli Vibrio spp., Aeromonas spp., and Shewanella spp. are a major cause of severe waterborne infection. The aim of this study was to assess the clinical and microbiological characteristics and prognosis of patients hospitalized in Reunion Island for a waterborne infection. This retrospective study was conducted in the two university hospitals of Reunion Island between January 2010 and March 2017. Patients diagnosed with a Vibrio, Aeromonas, or Shewanella infection were evaluated. Over the study period, 112 aquatic strains were isolated at Reunion Island: Aeromonas spp. were found in 91 patients (81.3%), Shewanella spp. in 13 patients (11.6%), and Vibrio spp. in eight patients (7.2%). The in-hospital mortality rate was 11.6%. The main sites of infection were skin and soft tissue (44.6%) and the abdomen (19.6%). Infections were polymicrobial in 70 cases (62.5%). The most commonly prescribed empiric antibiotic regimen was amoxicillin-clavulanate (34.8%). Eighty-four percent of the aquatic strains were resistant to amoxicillin-clavulanate and more than > 95% were susceptible to third or fourth generation cephalosporins and fluoroquinolones. After multivariate analysis, the only independent risk factor of in-hospital mortality was the presence of sepsis (P < 0.0001). In Reunion Island, the most commonly isolated aquatic microorganisms were Aeromonas spp. Sepsis caused by aquatic microorganisms was frequent (> 50%) and associated with higher in-hospital mortality. This study suggests that empiric antibiotic regimens in patients with sepsis or septic shock caused by suspected aquatic microorganisms (tropical climate, skin lesion exposed to seawater…) should include broad-spectrum antibiotics (third or fourth generation cephalosporins).