ABSTRACT
The genus Listeria belongs to the phylum Firmicute, the order Bacillales, the class Bacilli, and the family Listeriaceae together with the genus Brochothrix. The Listeria is Gram-positive bacteria with low G+C content closely related to Bacillus, Clostridium, Enterococcus, Streptococcus, and Staphylococcus. Nyfeldt reported the first confirmed isolation from humans in Denmark. Listeriosis should be differentiated from influenza, tuberculous meningitis, and rabies, brucellosis, pasteurellosis, toxoplasmosis, especially in abortion cases. The genetic subtyping approach encompasses PCR-based approaches, PCR-restriction fragment length polymorphism, ribotyping, pulsed-field gel electrophoresis, and DNA sequencing-based subtyping techniques, e.g., multilocus sequence typing. Lineage II strains are commonly isolated from food and animals with listeriosis, whereas outbreaks of human listeriosis are associated with lineage I. Lineages III and IV strains are rare and mostly isolated from animal sources. Listeriosis can be prevented in humans by taking care during handling of the abortion cases in both humans and animals, avoiding consumption of contaminated foodstuffs and cross-infections, especially among infants in hospitals.
