Table 3. Pathogenicity profiles of Listeria species recovered from udder raw fresh whole milk of goat and sheep.
Source of milk samples | Listeria species | Pathogenicity profile | PCR profile of virulence associated genes | ||||||||||||
CAMP (±) with S/R | PI-PLC | DLABN | DAPN | Anton's eye test | Mice lethality | Chick-embryo lethality | Vero cell ingestion assay | Biofilm | |||||||
Christensen's tube | Microtiter plate assay | hlyA | plc</emph>B | actA | iap | ||||||||||
L. monocytogenes (ATCC 7494) | ± | + | − | − | + | + | + | + | Strong | Strong (OD = 0.158) | + | + | + | + | |
Goat | L. innocua | − | − | + | + | − | − | − | − | Weak | Strong (OD = 0.159) | _ | _ | _ | _ |
L. seeligeri | − | − | + | + | − | − | − | − | Moderate | Strong (OD = 0.221) | + | _ | _ | _ | |
L. welshimeri | − | − | + | + | − | − | − | − | Moderate | Very strong OD = 0.112) | _ | _ | _ | _ | |
Sheep | L. innocua | − | − | + | + | − | − | − | − | Moderate | Strong (OD = 0.107) | _ | _ | _ | _ |
L. grayi | − | − | + | + | − | − | − | − | Weak | Strong (OD = 0.127) | _ | _ | _ | _ | |
L. grayi | − | − | + | + | − | − | − | − | Moderate | Strong (OD = 0.126) | _ | _ | _ | _ |
CAMP: Christie, Atkins, Munch-Petersen test; S/R: Staphylococcus aureus/Rhodococcus equi; PI-PLC: phosphatidylinositol-specific phospholipase C; DLABN: DL-alanine-beta-naphthylamide HCl; DAPN: d-alanine-p-nitroanilide; OD: optical density; OD < 0.1 = weak; OD 0.1 = strong; OD > 0.1 = very strong.