Table 1.
Characteristics of species of genus Listeria related to human and animal cases [8,9,22,26,27,29,32,35,46,335]. PI-PLC is an important Listeria enzymatic marker used routinely in selective chromogenic culture media for discrimination and enumeration of L. monocytogenes-L. ivanovii and other Listeria spp. in human specimens, food products and environmental samples (e.g. ALOA and RAPID’L.mono Agar Plates)
| L. monocytogenes Lineage I | L. monocytogenes Lineage II | L. monocytogenes Lineage III and IV | L. ivanovii | L. innocua | L. seeligeri | |
|---|---|---|---|---|---|---|
| LIPI −1 | + | + | + | + | -(rare isolates are +) | Some isolates are + (with some gene rearrangements) |
| InlA/B locus | + | + (>30% isolates present truncated InlA) |
+ | + | -(Rare isolates possess InlA) | - |
| LIPI −3 | Present in ≈ 50% Lineage I isolates | - | - | - | Present in ≈ 20% isolates | - |
| LIPI −4 | Mostly present in CC4 | - | Some isolates are + | - | + | - |
| LIPI −2 | - | A highly virulent hybrid sub-lineage harbors a truncated LIPI-2 | - | + | - | - |
| Virulence | +++ (specially CC1, CC2, CC4, and CC6) Overrepresented among human isolates |
+ Overrepresented among food and food-related isolates |
+ Most isolates obtained from animals |
Mainly animal cases Rare human cases |
-Rare human cases | -Rare human cases |
| Hemolysis | + | + | + | +++ (due to the sphingomyelinase SmcL) |
-(Rare isolates are +) | LIPI −1 + strains are hemolytic |
| Phosphatidylinositol-specific phospholipase C (PI-PLC coded by plcA) | + | + | + | + | -(Rare LIPI −1 + strains have PI-PLC activity) | LIPI −1 + strains have PI-PLC activity |