Francisella novicida infection in a patient with pulmonary infection and pancreatitis in Italy.

Tularemia is a rare but potentially life threatening zoonotic disease caused by Francisella tularensis . F. novicida , previously considered a subspecies of F. tularensis , is currently considered a separate species. Human infections related to F. novicida are exceedingly rare but can cause morbidity and mortality in debilitated or immunocompromised individuals.A 42-year-old male presented at the hospital with vomiting, dehydration, constipation and pain in the right iliac fossa. He was first diagnosed with pancreatitis and admitted for further analysis. Chest computerized tomography scan showed the presence of parenchymal consolidation in the left upper and lower lobes of the lung with pleural effusion. Blood cultures isolated a Gram-negative coccobacillus, that was at first identified by MALDI-TOF as  Francisella tularensis.  Serological analysis for the detection of total antibodies against  F. tularensis  and Real-Time PCR targeting the gene coding for 23 kDa, resulting negative. Subsequently, PCR targeting  helicases  and  tul4  genes, and the Regions of Difference  RD1  and  RD6  were performed allowing the identification of  F. novicida . The isolate was further genetically characterized by whole genome sequencing (WGS).This is the first reported case of human infection caused by  F. novicida  in Italy.Given the rarity of human cases and the lack of specific symptoms, this pathogen is difficult to identify and the diagnosis can be extremely challenging. In this case report, despite the lack of amplification of the gene encoding for 23 kDa protein, the identification of  Francisella  species was achieved with the amplification of different genes and characterized by WGS.
Competing Interests: None.
(© 2024 The Authors. Published by Elsevier Ltd.)