Correction: Intestinal microbiome profiles in broiler chickens raised without antibiotics exhibit altered microbiome dynamics relative to conventionally raised chickens.

[This corrects the article DOI: 10.1371/journal.pone.0301110.].

Intestinal microbiome profiles in broiler chickens raised without antibiotics exhibit altered microbiome dynamics relative to conventionally raised chickens.

The present study was undertaken to profile and compare the cecal microbial communities in conventionally (CONV) grown and raised without antibiotics (RWA) broiler chickens. Three hundred chickens were collected from five CONV and five RWA chicken farms on days 10, 24, and 35 of age. Microbial genomic DNA was extracted from cecal contents, and the V4-V5 hypervariable regions of the 16S rRNA gene were amplified and sequenced. Analysis of 16S rRNA sequence data indicated significant differences in the cecal microbial diversity and composition between CONV and RWA chickens on days 10, 24, and 35 days of age. On days 10 and 24, CONV chickens had higher richness and diversity of the cecal microbiome relative to RWA chickens. However, on day 35, this pattern reversed such that RWA chickens had higher richness and diversity of the cecal microbiome than the CONV groups. On days 10 and 24, the microbiomes of both CONV and RWA chickens were dominated by members of the phylum Firmicutes. On day 35, while Firmicutes remained dominant in the RWA chickens, the microbiome of CONV chickens exhibited am abundance of Bacteroidetes. The cecal microbiome of CONV chickens was enriched with the genus Faecalibacterium, Pseudoflavonifractor, unclassified Clostridium_IV, Bacteroides, Alistipes, and Butyricimonas, whereas the cecal microbiome of RWA chickens was enriched with genus Anaerofilum, Butyricicoccu, Clostridium_XlVb and unclassified Lachnospiraceae. Overall, the cecal microbiome richness, diversity, and composition were greatly influenced by the management program applied in these farms. These findings provide a foundation for further research on tailoring feed formulation or developing a consortium to modify the gut microbiome composition of RWA chickens.

Rutin attenuates inflammatory responses induced by lipopolysaccharide in an in vitro mouse muscle cell (C2C12) model.

White striping (WS) and woody breast (WB) are 2 of the major myopathies in the modern poultry industry. Even though the exact etiology for WS and WB is still unknown, differentially expressed genes in broiler breast muscle affected by WS and WB indicate that oxidative stress and inflammation could be involved in their occurrences. Therefore, it is very important to identify natural compounds with anti-oxidative stress and anti-inflammation properties that can reduce the occurrences of WS and WB in broiler chickens. Rutin is a polyphenol antioxidant that has been reported to be present in several plant extracts. In the current study, we established an in vitro inflammation model by using mouse muscle cells (C2C12) and evaluated the effects of rutin on lipopolysaccharide (LPS)-induced inflammatory responses in the muscle cells. Interleukin 6 (IL-6) secretion was measured by enzyme-linked immunosorbent assay. The mRNA abundance of cytokines and inducible nitric oxide synthase (iNOS) was measured by real-time PCR. Nuclear factor kappa B (NF-κB) activation was detected by electrophoretic mobility shift assay. The results showed that LPS (25 ng/ml) stimulation quickly activated NF-κB and induced significant IL-6 expression on both mRNA and protein levels (P < 0.05) in cells when compared with control cells without the LPS treatment. The rutin treatment decreased IL-6 mRNA abundance induced by LPS in a dose-dependent manner (P < 0.05). LPS-induced tumor necrosis factor-alpha and iNOS gene expression was significantly attenuated by 100 µM of rutin (P < 0.05). Moreover, LPS induced reactive oxygen species (ROS) production, and NF-κB activation was significantly blocked by 100 µM of rutin. These results suggest that rutin can attenuate LPS-induced inflammation in muscle cells and supplementation of rutin or rutin-containing plant extracts may present a promising approach to control WS and WB in broiler chickens.

Cas9-mediated allelic exchange repairs compound heterozygous recessive mutations in mice.

We report a genome-editing strategy to correct compound heterozygous mutations, a common genotype in patients with recessive genetic disorders. Adeno-associated viral vector delivery of Cas9 and guide RNA induces allelic exchange and rescues the disease phenotype in mouse models of hereditary tyrosinemia type I and mucopolysaccharidosis type I. This approach recombines non-mutated genetic information present in two heterozygous alleles into one functional allele without using donor DNA templates.