Salmonella enteritidis contamination of eggs from hens inoculated by vaginal, cloacal, and intravenous routes

Laying hens were inoculated intravaginally (IVg) once (IVg-single) or three times (IVg-triple), intracloacally (IC), or intravenously (IV) with Salmonella enteritidis (SE) phage type 4. Eggs tested were significantly (P < 0.05) fewer positive in group IC than in other groups. SE was recovered from egg contents in the groups IVg-single (9.6%), IVg-triple (4.2%), and IV (11.5%). IVg and IC inoculation resulted in colonization of the cloaca and lower portions of the oviduct but not the portion above the isthmus, whereas IV inoculation resulted in colonization of the entire oviduct. Only IV inoculation resulted in colonization of the ovary. In group IV, SE was recovered from three of six eggs found in the oviduct at necropsy, but in other groups, SE was not recovered from 53 eggs in the oviduct. The results suggested that the SE infection of vagina resulted in a frequent incidence of contaminated eggs and that SE adhered to the eggs from the contaminated vagina might pass through shells and shell membranes.