Reduced environmental bacterial load during early development and gut colonisation has detrimental health consequences in Japanese quail.

Gastrointestinal colonisation by commensal microbiota is essential for the health and well-being of the host. We aimed to evaluate the influence of a reduced bacterial load environment on microbiota development and maturation, and the possibility of targeted colonisation via at-hatch administration of a selected bacterial strain. Japanese quail (Coturnix japonica) were inoculated within 1 h of hatch with a freshly grown culture of a Lactobacillus agilis isolate derived from a healthy adult quail. Hatchlings were kept in a mouse isolator for one week and then housed between one and four weeks of age, with a flock of normally grown adult quail to expose the bacteria-restricted birds to normal commensal quail bacteria. The bacterial isolate used to inoculate the birds was found to completely dominate the microbiota of the intestine of L.agilis at-hatch inoculated birds. Despite 3 weeks of co-housing of the test birds with an adult flock harbouring normal rich gut microbiota, neither the Lactobacillus inoculated nor PBS inoculated birds reached the level of bacterial diversity seen in birds raised under normal conditions. Neither PBS nor Lactobacillus inoculated birds were able to adopt normal quail microbiota after one week of restricted exposure to bacteria, indicating that contact with diverse microbiota during the early days of gut development in birds is critical for the establishment of healthy intestinal community. Very early intervention in the form of a suitable bacterial probiotic inoculant immediately post-hatch protected birds grown in extreme hygiene conditions from developing anomalous gut microbiota and intestinal damage. Our data shows that it is possible to induce dominance of desired strain using simple timed manipulation.

Ultrastructure of the gastro intestinal tract of healthy Japanese quail (Coturnix japonica) using light and scanning electron microscopy.

The Japanese quail (Coturnix japonica) are popular both as an alternative protein source and as a model of choice for scientific research in several disciplines. There is limited published information on the histological features of the intestinal tract of Japanese quail. The only comprehensive reference is a book published in 1969. This study aims to fill that niche by providing a reference of general histological features of the Japanese quail, covering all the main sections of the intestinal tract. Both light and scanning electron microscope (SEM) images are presented. Results showed that the Japanese quail intestinal tract is very similar to that of the chicken with the exception of the luminal koilin membrane of the gizzard. Scanning electron microscopic photomicrographs show that in the Japanese quail koilin vertical rods are tightly packed together in a uniform manner making a carpet-like appearance. This differs in chicken where the conformations of vertical rods are arranged in clusters.

A low dose of an organophosphate insecticide causes dysbiosis and sex-dependent responses in the intestinal microbiota of the Japanese quail (Coturnix japonica).

Organophosphate insecticides have been directly or indirectly implicated in avian populations declining worldwide. Birds in agricultural environments are commonly exposed to these insecticides, mainly through ingestion of invertebrates after insecticide application. Despite insecticide exposure in birds occurring mostly by ingestion, the impact of organophosphates on the avian digestive system has been poorly researched. In this work we used the Japanese quail (Coturnix japonica) as an avian model to study short-term microbial community responses to a single dose of trichlorfon at low concentration in three sample origins of the gastrointestinal tract (GIT): caecum, large intestine and faeces. Using next-generation sequencing of 16S rRNA gene amplicons as bacterial markers, the study showed that ingestion of insecticide caused significant changes in the GIT microbiome. Specifically, microbiota composition and diversity differed between treated and untreated quail. Insecticide-associated responses in the caecum showed differences between sexes which did not occur with the other sample types. In caecal microbiota, only treated females showed significant shifts in a number of genera within the Lachnospiraceae and the Enterobacteriaceae families. The major responses in the large intestine were a significant reduction in the genus Lactobacillus and increases in abundance of a number of Proteobacteria genera. All microbial shifts in faeces occurred in phylotypes that were represented at low relative abundances. In general, changes in microbiota possibly resulted from contrasting responses towards the insecticide, either positive (e.g., biodegrading bacteria) or negative (e.g., insecticide-susceptible bacteria). This study demonstrates the significant impact that organophosphate insecticides have on the avian gut microbiota; showing that a single small dose of trichlorfon caused dysbiosis in the GIT of the Japanese quail. Further research is necessary to understand the implications on birds' health, especially in females.

The gastrointestinal tract microbiota of the Japanese quail, Coturnix japonica.

Microbiota in the gastrointestinal tract (GIT) plays an essential role in the health and well-being of the host. With the exception of chickens, this area has been poorly studied within birds. The avian GIT harbours unique microbial communities. Birds require rapid energy bursts to enable energy-intensive flying. The passage time of feed through the avian GIT is only 2-3.5 h, and thus requires the presence of microbiota that is extremely efficient in energy extraction. This investigation has used high-throughput 16S rRNA gene sequencing to explore the GIT microbiota of the flighted bird, the Japanese quail (Coturnix japonica). We are reporting, for the first time, the diversity of bacterial phylotypes inhabiting all major sections of the quail GIT including mouth, esophagus, crop, proventriculus, gizzard, duodenum, ileum, cecum, large intestine and feces. Nine phyla of bacteria were found in the quail GIT; however, their distribution varied significantly between GIT sections. Cecal microbiota was the most highly differentiated from all the other communities and showed highest richness at an OTU level but lowest richness at all other taxonomic levels being comprised of only 15 of total 57 families in the quail GIT. Differences were observed in the presence and absence of specific phylotypes between sexes in most sections.