Invasive infection: shedding light on a rare pathogen in a retrospective cohort analysis.

are Gram-negative, facultatively anaerobic rods or coccobacilli that are infrequently encountered as pathogens causing infection. The range of invasive infection that cause is poorly described. The pathogenicity of species such as is debated. To identify invasive infection due to species in a large healthcare organization and to characterize clinical syndromes, co-morbidities and risk factors. All microbiological samples positive for species were identified by conventional culture or 16S rRNA PCR between October 2017 and March 2021. Electronic records for all patients with positive samples were reviewed and the infection syndrome classified for patients with invasive disease. Twenty-seven patients with invasive infection were identified, with a statistically significant difference in species-specific patterns of invasive infection (=0.02) and a statistically significant association with residence in the 30 % most deprived households in the UK by postcode (<0.01). The three most common co-morbidities were periodontitis or recent dental work (29.6%), cardiovascular disease (25.9%) and diabetes (18.5 %). We describe a novel association of with skin and soft tissue infection. The propensity of the species to cause invasive infection at different body sites and be associated with deprivation is reported. bacteraemia was associated with infective endocarditis, and was implicated in severe appendicitis and noted to cause brain abscess. Areas warranting future research include exploring the risk-factors required for invasive infection and those that may determine the species-specific differences in patterns of invasive disease.