Francisella novicida

Francisella novicida is a bacterium of the Francisellaceae family, which consist of Gram-negative pathogenic bacteria. These bacteria vary from small cocci to rod-shaped, and are most known for their intracellular parasitic capabilities. In this family, six species have been identified; however, the species F. novicida is under intense scrutiny. Though some believe it should be classified with its own species designation, others argue it should be reclassified as a subspecies under F. tularensis. If it were to be classified as a subspecies, F. novicida would join the other known subspecies including F. t. tularensis (type A) and F. t. holarctica (type B). Biochemical assays for identifying F. tularensis subtypes and strains are not ideal because the results are often non-definitive and subject to variation, therefore these assays should only be considered as supplementary tests for identification of Francisella species and subspecies. Several strains of F. novicida or F. novicida-like bacteria have been described, and these strains may be resolved by PCR-based methods.