|Byrd Ii, James - Allen|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2003
Publication Date: 7/6/2003
Citation: Moore, R.W., Howard, Z.R., Zabala-Diaz, I.B., Kubena, L.F., Byrd Ii, J.A., Nisbet, D.J., Birkhold, S.C., Ricke, S.C. 2003. Effects Of Ovarian Follicular Maturation On Salmonella Invasion. Poultry Science Vol 82 Supplement 1, p43.
Technical Abstract: Transovarian transmission of paratyphoid Salmonella is well documented and occurs at a low incidence in chickens. However, the exact mechanism of follicular invasion is not well understood. The following study investigates the ability of Salmonella to invade ovarian follicles at different stages of follicular maturity in vitro. Ovarian follicles were collected from Leghorn hens and separated into three stages of maturity: 1) large yellow follicles or F follicles (LYF), 2) small yellow follicles (SYF), and 3) small white follicles (SWF). All follicles were incubated at 37°C in RPMI 1640 medium. Initially, follicles were incubated with l million cfu/mL of Salmonella Typhimurium (ST) sensitive to gentamicin for 0, 0.5, 1, or 2 h. Follicles were then removed from the ST culture, rinsed in fresh medium, and placed in medium containing gentamicin sulfate for 5 h to kill any ST which had not invaded the follicular membrane. After the 5 h incubation, follicles were rinsed in fresh medium and stomached in phosphate buffered saline. Serial dilutions were made of each follicle and viable ST cells were enumerated on brilliant green agar. Two identical trials were conducted. In trial 1, a numerical increase in ST invasion was observed in the SWF as compared to the LYF and SYF (at 2 hr, SWF= 6667±3865, SYF= 67±33, and LYF= 1865±365 cfu ST/mL). Additionally, a numerical increase in ST invasion was observed in the LYF as compared to the SYF. In trial two, it was observed that ST invasion of SWF was significantly greater than in SYF or LYF (at 2 hr, SWF=9233±2895, SYF=100±100, and LYF=550±250 cfu ST/mL). A numeric increase in recoverable ST was also observed in the LYF as compared to the SYF in trial two. These data suggest that ST may differentially invade ovarian follicles depending on maturity of the follicle, and that SWF may be more susceptible to ST invasion than either the SYF or the LYF.