Salmonella Enteritidis

Outbreaks of human salmonellosis initiated by Salmonella Enteritidis have spectacularly increasedthroughout the world since the mid-to-late 1980s and have become an significant difficulty for the poultry commerce and public wellbeing (Rodrigue et al., 1990; Fris and Van den Bos, 1995; Hogue et al., 1997). Epidemiologic investigates have proposed contaminated for demonstration or egg goods as the foremost source of contamination (Van de Giessen et al., 1992; Altekruse et al., 1993; Hedberg et al., 1993; Henzler et al., 1994). However, it has not been verified why S. Enteritidis has been the predominant serovar affiliated with egg-borne salmonellosis in humans. As S. Enteritidis is the serovar most often isolated from for demonstration, it may have exclusive characteristics or proficiency to contaminate eggs. Understanding the means of egg contamination with S. Enteritidis is absolutely crucial to eradicate human salmonellosis by contaminated eggs. S. Enteritidis is discovered in all egg constituents prepared by contaminated hens: yolk, albumen, eggshell membrane and eggshell. Two likely paths of egg contamination by S. Enteritidis are considered: (1) direct contamination of yolk, albumen, eggshell membranes or eggshells before oviposition originating from contaminated reproductive body components and (2) penetration through the eggshell from the colonized cloaca or feces after or throughout oviposition. Different segments of the reproductive body components may disagree in their susceptibility to S. Enteritidis colonization and invasion. Thiagarajan et al. (1994, 1996) recount that S. Enteritidis can invade and reproduce in granulosa units of the preovulatory follicle. De Buck et al. (2003, 2004a) focus that the isthmus is the most often and very powerfully contaminated segment of the oviduct.

 

MATERIALS AND METHODS

Experimental birds

Approximately 300-day-old Boris Brown (Hy-Line Brown) laying hens were got from the lone flock of a localized financial level ranch (NICHIWA, Hyogo, Japan). They were free of any clear-cut infections all through the increasing and laying periods. Experimental hens were housed in one-by-one cages in an isolated facility under a 12-h light/12-h dark photoperiod. They were supplied with non-medicated nourishment and water provided publicity libitum. No Salmonella was noticed from cloacal swabs and feces of all birds throughout the acclimation time span, over 10 days before use. The birds were organised according to The Standards Relating to the Care and Management of Experimental Animals (Japan).

 

Preparation of vaginal and follicular explants

Hens were euthanized by an intravenous injection of pentobarbital sodium solution. The vagina and ovary were assembled aseptically and cleaned softly with Dulbecco's Modified Eagle's Medium (DMEM, Sigma-Aldrich Japan K.K., Tokyo, Japan). The vaginal segments put on sterilized Petri bowls topped up with DMEM were opened longitudinally and 8 mm diameter parts of vaginal explants were slash aseptically utilising Biopsy Punch (Kai commerce, Gifu, Japan). The ovarian epithelia were taken and 4-6 mm diameter preovulatory follicles were assembled aseptically. The vaginal and follicular explants were put up on sterilized 24-well flat base tissue heritage plates encompassing 900 ml of DMEM.

 

Bacteria

The Salmonella strains utilised in this study and their initial isolation causes are shown in Table 1. All strains were provided ...