Influence of penicillin on microbial diversity of the cecal microbiota in broiler chickens

Abstract

Antibiotic growth promoters have been used for growth promotion of chickens in poultry industry since 1940. Recently, concerns have been raised to the use of antibiotic growth promoters in livestock due to development of antibiotic resistance in bacteria. The objective of our study was to investigate the effect of penicillin supplementation in the feed on cecal microbiota of broiler chickens. Two groups (n = 30) of chickens were fed corn-soybean meal diets with and without supplementation of penicillin at the concentration of 55 mg/kg (ANT vs. CON, respectively). At 18 d of age, the ANT group had significantly (P ≤ 0.05) higher mean BW than the CON group (668.6 vs. 570.0 g). Cecal samples of 5 randomly selected birds were pooled from each group and used for genomic DNA isolation and PCR amplification of 16S rRNA gene; 454 pyrosequencing of the amplicons resulted in 7,881 and 11,214 sequence reads for ANT and CON groups, respectively. Phylogenetic analysis indicated that penicillin supplementation in the ANT group resulted in an elevated proportion of phylum Firmicutes from 58.15 to 91.5% and a decreased proportion of phylum Bacteroidetes from 31.1 to 2.96% compared with the CON group. Recent studies conducted in humans, pigs, and mice have shown a similar shift in gut microbiota in obese individuals compared with the lean ones, indicating that this microbial shift could be responsible for the increase in energy harvest and BW. The results of this study suggest that the growth-promoting effect of penicillin supplementation in broilers may be mediated by a similar microbial process.

Effects of the Brown Seaweed Laminaria japonica Supplementation on Serum Concentrations of IgG, Triglycerides, and Cholesterol, and Intestinal Microbiota Composition in Rats

“…EU381820_g, EF445272_g , and AM275436_f_uc are the genera that fall under the class Mollicutes . Mollicutes and Oscillibacter were shown to increase in obese mouse fed with high-fat diets, which then caused mild inflammations to affect the insulin pathway leading to fat accumulation (11, 35). L. japonica (DLJ and HLJ) and FOS-added L. japonica (FHLJ) reduced the relative abundance of obesity-associated genera in rat intestine (Figure 4A).…”

Investigating the Association Between the Caecal Microbiomes of Broilers and Campylobacter Burden

“…A study by Singh et al (2013) suggested that Firmicutes to Bacteroidetes ratio based on 16S rRNA sequencing could be correlated with the weight of the birds and antibiotic treatment. A further study also suggested that antibiotic treatment altered gut and fecal bacterial species composition in chickens toward an increased abundance of Lactobacillus spp., Clostridiales and Enterobacteriaceae (Gong et al, 2008).…”

Antibiotics in Canadian poultry productions and anticipated alternatives

“…A functional analysis of environmental gene tags (EGTs) revealed that in the salinomycin-treated birds there was an increased abundance of the cell wall and capsule, iron acquisition, motility and β-lactamase gene categories while a decrease of multidrug efflux pump EGTs was detected (Fung et al, 2013). In addition to such Canadian studies, other authors demonstrated the impact of antimicrobial growth promoters on the chicken gut microflora (Knarreborg et al, 2002; Torok et al, 2011; Singh et al, 2013). For example, pyrosequencing followed by phylogenetic analyses indicated that diet supplementation with penicillin resulted in an elevated proportion of bacteria of the phylum Firmicutes from 58.1 to 91.5% and a decreased proportion of members of the phylum Bacteroidetes from 31.1 to 2.9% in the gut microflora of broilers compared to that observed in broilers fed with the control non-supplemented diet (Singh et al, 2013).…”