title: 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.
authors.affiliation: Cell and Molecular Biology Program, University of Arkansas, Fayetteville 72701, USA.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Singh
authors.forename: Ahmad
authors.initials: A
authors.lastname: Karimi
authors.forename: Kshitiz
authors.initials: K
authors.lastname: Devendra
authors.forename: Park W
authors.initials: PW
authors.lastname: Waldroup
authors.forename: Kwang Keun
authors.initials: KK
authors.lastname: Cho
authors.forename: Young Min
authors.initials: YM
authors.lastname: Kwon
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D002432:Cecum / Q000382:microbiology*; D002645:Chickens / Q000382:microbiology*; D004269:DNA, Bacterial / Q000145:classification / Q000302:isolation & purification; D008297:Male; D010406:Penicillins / Q000494:pharmacology*; D010802:Phylogeny
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D010406:Penicillins