Non-typhoidal Salmonella enteritidis prosthetic valve endocarditis.

In this case, we present a rare cause of prosthetic valve endocarditis. A man in his 80s presented to the emergency department with fever and diarrhoea. The patient underwent a transcatheter aortic valve replacement 17 years earlier. A negative PCR result in faeces for Salmonella and positive blood cultures with Salmonella gave rise to the suspicion of an intravascular Salmonella infection, which was confirmed with a positron emission tomography. Due to the low prevalence of Salmonella endocarditis, there is no consensus on the most effective treatment. Guidelines recommend early surgery and long-term antimicrobial treatment in endocarditis with Gram-negative bacteria. In this case, surgery was not deemed feasible given the patient his advanced age and multiple comorbidities. Despite treatment with intravenous antibiotics, the patient succumbed to progression of endocarditis 37 days after admission.

A dynamic flow model mimicking duodenoscope reprocessing after bacterial contamination for translational research.

Objective: Duodenoscopy-associated infections and outbreaks are reported globally despite strict adherence to duodenoscope reprocessing protocols. Therefore, new developments in the reprocessing procedure are needed. Design: We evaluated a novel dynamic flow model for an additional cleaning step between precleaning and manual cleaning in the reprocessing procedure. Methods: A parallel plate flow chamber with a fluorinated ethylene propylene bottom plate was used to mimic the duodenoscope channels. The flow chamber was inoculated with a suspension containing Klebsiella pneumoniae to simulate bacterial contamination during a duodenoscopic procedure. After inoculation the flow chamber was flushed with a detergent mimicking precleaning. Subsequently the flow chamber was subjected to different interventions: flow with phosphate-buffered saline (PBS), flow with 2 commercial detergents, flow with sodium dodecyl sulfate with 3 different concentrations, and flow with microbubbles. Adhering bacteria were counted using phase-contrast microscopy throughout the experiment, and finally, bacterial viability was assessed. Results: During precleaning both PBS and 1% (v/v) Neodisher Mediclean Forte were able to desorb bacteria, but neither proved superior. After precleaning only sodium dodecyl sulfate could desorb bacteria. Conclusions: Flushing during precleaning is an essential step for reducing adhering luminal bacteria, and sodium dodecyl sulfate is a promising detergent for bacterial desorption from duodenoscope channels after precleaning.

Symptoms and PCR testing interval for bacterial pathogens in patients with diarrhoea.

Introduction . Acute diarrhoea can be caused by Salmonella species, Shigella species, Yersinia enterocolitica, Campylobacter species and Plesiomonas shigelloides (SSYCP). In clinical practice, however, polymerase chain reaction (PCR) for SSYCP is frequently performed as part of the diagnostic work-up for patients with chronic diarrhoea and gastrointestinal complaints.Hypothesis. This study postulates that PCR for SSYCP is of limited clinical use in patients with chronic diarrhoea and gastrointestinal complaints.Aim. The primary aim of this study is to evaluate whether testing for SSYCP remains sensible in patients with chronic diarrhoea and gastrointestinal symptoms and if earlier testing leads to more positive PCR results.Methodology. Between January 2017 and December 2018, data on PCR results, culture results, symptoms, symptom to testing interval (STI) and immune status were retrospectively collected from the medical records of patients with gastrointestinal symptoms for whom PCR results for SSYCP were available. The STIs of PCR-positive patients and PCR-negative patients were compared.Results. In total, 146 PCR-positive and 149 PCR-negative patients were included. STIs of <7 days occurred in 55 % of all PCR-positive patients compared to 38 % in PCR-negative patients. PCR-positive patients were more often tested within 7 days after onset of gastrointestinal symptoms or diarrhoea. A third of PCR-positive patients had an STI of >7 days. Immunocompromised patients had a shorter STI. Admitted patients had a shorter STI. Eighty-six PCR-positive patients had a positive culture (58 %). Antibiotic use 3 months prior to PCR testing was correlated with negative PCR results.Conclusions . This study shows that early testing correlates with more positive PCR results and underlines that PCR for SSYCP is of lesser importance in the diagnostic workup of chronic diarrhoea and/or gastrointestinal symptoms. The shorter STI found in immunocompromised patients is possibly due to a lower threshold for testing in this population. It is also important to take recent antibiotic use into consideration when interpreting PCR results, given the correlation between negative PCR results and antibiotic use. Careful and precise documentation of symptoms in medical records is essential for clinical practice and research.

A narrative review on current duodenoscope reprocessing techniques and novel developments.

Duodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

Yersinia pseudotuberculosis infection with severe localised inflammation and ulceration of the ileum in a heart transplant patient.

In this case, we present an uncommon gastrointestinal infection in an immunocompromised patient that was solely diagnosed because of close collaboration between treating physicians and microbiologists. The patient is a 42-year-old male who underwent heart transplantation 5 years earlier. He presented with fever, weight loss, diarrhoea and tiredness. Initial investigations could not elucidate the aetiology of his symptoms. The patient was referred to the department of infectious diseases for further evaluation. Serology for Yersinia species was ordered and the result was suggestive for the possibility of a Yersinia species infection. Close collaboration between treating physicians and microbiologists followed and led to additional investigations, which revealed the diagnosis of a Yersinia pseudotuberculosis infection with extensive lesions in the gastrointestinal tract. Treatment with ciprofloxacin resulted in complete resolution of symptoms and healing of the gastrointestinal lesions. In conclusion, this case underlines the need for a multidisciplinary approach to complex patients of which symptoms have yet to be understood.