Shewanella putrefaciens, a rare cause of osteomyelitis

Left knee septic monoarthritis in a pediatric patient due to shewanella putrefaciens: case report and literature review

BACKGROUND

Shewanella putrefaciens is a gram-negative, nonfermenting, oxidase-positive, hydrogen sulfide-producing bacillus and a halophilic bacterium, known for causing unusual infections in humans and often regarded as an opportunistic pathogen. Its diverse symptoms have a significant impact on human health, with 260 documented disorders reported in the literature over the last 40 years, highlighting its potential danger.

CASE PRESENTATION

We present the case of a previously healthy 15-year-old male patient who sustained a self-inflicted sharp-object injury while working in the field, resulting in secondary septic monoarthritis due to Shewanella putrefaciens.

CONCLUSIONS

This case highlights the bacteriological and clinical characteristics, as well as the antibiogram, of Shewanella spp. Given the recent increase in notifications of Shewanella infections, predominantly by S. algae and S. putrefaciens, it is essential to consider these pathogens in patients with a history of contact with bodies of water. Special attention must be paid to their resistance patterns in patient management to prevent the development of intrinsic antimicrobial resistance.

Severe Shewanella Cellulitis Following Saltwater Exposure in an Elderly Patient

Shewanella algae is an opportunistic Gram-negative bacillus primarily found in marine environments. It can cause a range of infections in humans, from superficial soft tissue infections to more severe conditions like bacteremia, otitis, and hepatobiliary infections. While infections are rare, they can be significant, leading to complications such as sepsis and tissue necrosis. We present the case of severe cellulitis caused by Shewanella in an 88-year-old patient with multiple comorbidities. Following a blue crab pinch and consequent saltwater exposure, the patient developed severe cellulitis, sepsis, delirium, and atrial fibrillation. Despite these complications and the patient's age, a prompt diagnosis and a combination of antibiotic treatments led to a successful recovery. This case is notable for its illustration of the potential severity and diverse clinical presentation of Shewanella infections. It highlights the importance of considering Shewanella as a possible pathogen in cases of saltwater exposure and teaches management in elderly, multi-morbid patients.

Shewanella putrefaciens, a rare human pathogen: A review from a clinical perspective

Shewanella putrefaciens is a gramnegative, facultatively anaerobic, rod shaped bacterium. It belongs to the class of the Gammaproteobacteria and was first described in 1931. S. putrefaciens is part of the marine microflora and especially present in moderate and warm climates. The bacterium is a rare oppurtonistic human pathogen associated mainly with intra-abdominal as well as skin and soft tissue infections. However, it has also been reported in association with more severe diseases such as pneumonia, intracerebral and ocular infections and endocarditis. In these cases the clinical courses are often associated with underlying, predisposing diseases and risk factors. For successful treatment of S. putrefaciens, a combination of appropriate local therapy, e.g. surgical treatment or drainage, and antibiotic therapy should be performed. Since multiple resistances to antibiotics are described, the results of the antimicrobial susceptibility testing must be considered for effective therapy as well. Furthermore, a main challenge in clinical practice is the accurate microbiological identification, and especially the correct differentiation between S. putrefaciens and S. algae. Under certain circumstances, Shewanella-infections can have severe, sometimes even fatal consequences. Therefore, we decided to present the current state of knowledge as well as further aspects with regard to future diagnostics, therapy and research.

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.

Bacterial Flora Associated with Diseased Freshwater Ornamental Fish

Introduction

Ornamental fish can suffer from different bacterial diseases. Among them the most prevalent are infections caused by Aeromonas, Shewanella, Citrobacter, Plesiomonas, Edwardsiella, and Pseudomonas. But there is a broad spectrum of rarely identified bacteria which may be causative agents of diseases. The aim of the study was to determine the species of bacteria pathogenic for fish which are prevalent in aquariums.

Material and Methods

Bacteria were isolated from infected ornamental fish from pet shops and private aquariums in the Lublin region in 2015 and classified to species using MALDI-TOF MS.

Results

A total of 182 isolates from ornamental fish were identified. The most frequent bacteria found in diseased fish were Aeromonas veronii (30.8% of total number of strains), A. hydrophila (18.7%), Shewanella putrefaciens (7.1%), Citrobacter freundii (7.1%), Pseudomonas spp. (7.1%), Shewanella baltica (4.9%), and Plesiomonas shigelloides (3.3%).

Conclusion

Isolated bacterial species are facultative pathogens for fish and humans and may be isolated from fish without apparent symptoms of the disease.

Shewanella spp. infections in Gran Canaria, Spain: retrospective analysis of 31 cases and a literature review

INTRODUCTION

Shewanella spp. can cause severe skin and soft-tissue infections, gastrointestinal infections, otitis and bacteraemia, generally upon contact with seawater or consumption of raw seafood. Recently, a new condition termed 'patera foot' characterized by acute skin and soft-tissue infection has been described in irregular immigrants arriving to the Canary Islands, Spain, in rudimentary boats. Most infections are caused by a single species, Shewanella algae. The improvement of the diagnostic capabilities in clinical microbiology laboratories has resulted in a growing number of cases being reported worldwide, most of them coming from warm regions.

CASE PRESENTATION

In this work, we reviewed the medical records of all the patients with Shewanella infections in the two university hospitals of Gran Canaria (the Canary Islands, Spain) during the period 2000-2016, resulting in the identification of 31 cases. We also conducted a literature review of Shewanella infections reported worldwide in recent years.

CONCLUSION

This case series suggests that Shewanella infections are nosocomially acquired more frequently than previously thought. In addition, the unexpectedly high proportion of multidrug-resistant isolates raises concerns.