Cockatiel (Nymphicus hollandicus) gut microbiomes, bacterial inhabitants of a worldwide distributed pet

Background. Cockatiels (Nymphicus hollandicus) were originally endemic to Australia, but they are nowadays popular worldwide pet birds. It is now possible to make detailed molecular studies on cultivable and uncultivable bacteria that are part of the intestinal microbiome of healthy animals, these studies showed that bacteria are an essential part of the capacity and metabolic status of animals. There are few studies of bird microbiomes and to date this is the first reported cockatiel microbiome work. Methods. In this paper we analyzed the gut microbiome of 3 healthy adult cockatiel birds by massive sequencing of 16S ribosomal gene. Additionally, we show a comparison with other poultry, and wild birds microbiomes and their taxa profiles Results. The vast majority of the Cockatiel’s bacteria found were Firmicutes, while Proteobacteria and Bacteroidetes are poorly represented. 19,280 different OTUs were detected, of which 8,072 belong to the Erysipelotrichaceae family. Discussion. Cockatiels wide geographic distribution, and close human contact makes relevant to study their microbiomes, this study gives a baseline for their bacterial diversity. Cockatiels microbiomes diversity are dominated by Firmicutes of the Erysipelotrichaceae family. Cockatiels, and other wild birds are almost depleted of Bacteroidetes which happen to be abundant in poultry birds and this is probably related with the intensive human manipulation of poultry bird diets. Some pathogenic bacteria like Clostridium colinum, and Serratia marcescens are inhabitants of the cockatiel’s microbiome while other pathogens are not elements of healthy cockatiel’s microbiota, although the specimens collected were perfectly healthy at the time.