Comparison of culturing Mycoplasma gallisepticum from fresh eggs and 18-day-old embryos.
Twenty-four 70-week-old and sixteen 27-week-old white leghorn hens were challenged with R strain Mycoplasma gallisepticum (MG) by injection into the caudal thoracic air sac and infraorbital sinus. Eggs were collected daily and cultured within 7 days or incubated for 18 days. Vitelline membranes of eggs were cultured directly; in 18-day-old embryos, cultures were taken from the yolk sac, air sacs, and oral cavity. Culture of vitelline membrane of eggs within 2 days was compared with culture of eggs stored 10 days post oviposition. The first MG-positive egg was laid 2 days postinfection (PI). Hens continued to lay positive eggs to the end of the experiments. There was no significant difference in MG recovery between eggs cultured within 2 days and those cultured 10 days post oviposition. MG was isolated at a significantly higher rate from eggs than from 18-day-old embryos. MG was isolated at a higher rate from the yolk sac of 18-day-old embryos than from the air sacs or oral cavity of the same embryos.
Sasipreeyajan
J
J
College of Veterinary Medicine, University of Minnesota, St. Paul 55108.
Halvorson
D A
DA
Newman
J A
JA
D000818:Animals; D002642:Chick Embryo / Q000382:microbiology; D002645:Chickens / Q000382:microbiology*; D005260:Female; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D009174:Mycoplasma / Q000254:growth & development / Q000302:isolation & purification*; D009175:Mycoplasma Infections / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D010063:Ovum / Q000382:microbiology*; D011201:Poultry Diseases / Q000382:microbiology* / Q000635:transmission