Macrorhabdus

摘要: The information available about macrorhabdosis (aka megabacteriosis, virgamycosis, avian gastric yeast) in birds is confusing for those unfamiliar with the literature and sometimes equally as confusing for those who are. The organism was originally thought to be a yeast because of its staining characteristics. 3 Subsequently, Van Herck, et al, concluded that it was a bacterium, as they were unable to demonstrate cytoplasmic organelles or a nucleus. They did, however, show nuclear-like structures in Giemsa-stained organisms but interpreted them to be “granules.” 23 Scanlan and Graham reported isolating a bacterium from the stomach of budgerigars using standard microbiological techniques. The isolated bacterium, however, was smaller than the organism in vivo and was not characterized by periodic acid-Schiff (PAS) or silver stains. 20 Attempts by other investigators to grow this organism with standard microbiological isolation techniques have been unsuccessful. However, Gerlach reported isolation of this organism on MRS medium, a medium used for growing fungi, but was unable to maintain it past a few passages. 8 Huchzemeyer, et al, also reported isolating an organism from the proventriculus of ostriches using MRS agar. This organism had the same biochemical properties as the one isolated by Scanlan and Graham, but was smaller than those seen histologically, and its ability to stain with PAS and silver stains was not reported. 9