Traumatic endophthalmitis caused by Shewanella putrefaciens associated with an open globe fishhook injury

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.

First isolation and whole-genome sequencing of a Shewanella algae strain from a swine farm in Brazil

BACKGROUND

Infections caused by Shewanella spp. have been increasingly reported worldwide. The advances in genomic sciences have enabled better understanding about the taxonomy and epidemiology of this agent. However, the scarcity of DNA sequencing data is still an obstacle for understanding the genus and its association with infections in humans and animals.

RESULTS

In this study, we report the first isolation and whole-genome sequencing of a Shewanella algae strain from a swine farm in Brazil using the boot sock method, as well as the resistance profile of this strain to antimicrobials. The isolate was first identified as Shewanella putrefaciens, but after whole-genome sequencing it showed greater similarity with Shewanella algae. The strain showed resistance to 46.7% of the antimicrobials tested, and 26 resistance genes were identified in the genome.

CONCLUSIONS

This report supports research made with Shewanella spp. and gives a step forward for understanding its taxonomy and epidemiology. It also highlights the risk of emerging pathogens with high resistance to antimicrobial formulas that are important to public health.

Open globe and penetrating eyelid injuries from fish hooks

Background

A few case reports have described accidental eye injuries caused by fish hooks. The severity of ocular injuries is dependent on the involved ocular structures. Severe ocular injuries due to fish hooks are rare. We describe open globe and penetrating eyelid injuries from fish hooks at the Baltic Sea.

Methods

Nine patients with traumatic ocular injuries caused by fish hooks were included. The following parameters were evaluated: severity of injury, best corrected visual acuity at admission and last follow-up, and surgical treatment.

Results

All nine patients were male. Age ranged between 7 and 51 years with a median of 13 years. Sixty-seven percent of the patients were children. Four of the nine patients were 9 years or younger. In 5 eyes (55%) the injury was limited to the eyelid. An open globe injury was found in 4 patients (45%). The mean follow-up was 16.7 ± 32.8 months. All patients required surgical treatment. The number of operations ranged from 1 to 3, with a mean of 1.4. At admission and last follow-up, patients with eyelid injuries showed a median best corrected visual acuity (BCVA) of logMAR 0.0. Patients with open globe injuries showed a median best corrected visual acuity of logMAR 1.5 at admission, and of logMAR 0.6 at last follow-up.

Conclusions

Nearly half of the patients suffered severe penetrating injuries. Especially children misjudge the risk potential of fishing due to their lack of experience. Fishing glasses should be worn not only for UV protection, but also as injury prevention strategy.

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.

Current trends of human infections and antibiotic resistance of the genus Shewanella

Shewanella spp. are commonly known as environmental bacteria and are most frequently isolated from aquatic areas. Currently, diseases syndromes and multidrug resistance have increasingly been reported in the genus Shewanella. Some species are associated with various infections, such as skin and soft tissue infections, as well as bacteremia. Generally, these bacteria are opportunistic and mostly affect people with an impaired immune system. This genus is also a probable vehicle and progenitor of antibiotic resistance genes. In fact, several resistance genes and mobile genetic elements have been identified in some resistant species isolated from environmental or clinical settings. These genes confer resistance to different antibiotic classes, including those used in therapies such as β-lactams and quinolones, and are generally located on the chromosome. Recently, a multidrug-resistant (MDR) plasmid harboring several drug resistance genes associated with transposons and integrons has been identified in Shewanella xiamenensis. These antibiotic resistance genes can circulate in the environment and contribute to the emergence of antibiotic resistance. This review describes different aspects of Shewanella, focusing on the infections caused by this genus, as well as their role in the propagation of antibiotic resistance via mobile genetic elements.