title: Antimicrobial activity and safety evaluation of Enterococcus faecium KQ 2.6 isolated from peacock feces.
abstract: BACKGROUND
  The objective of this paper was to study antimicrobial activity and safety of Enterococcus faecium KQ 2.6 (E. faecium KQ 2.6) isolated from peacock feces.
  
  
  METHODS
  Agar well diffusion method was adopted in antimicrobial activity assay. Disk diffusion test was used to determine the antibiotic resistance. The identification and virulence potential of E. faecium KQ 2.6 were investigated using PCR amplification.
  
  
  RESULTS
  The results indicated that cell free supernatant (CFS) of the strain had the good antimicrobial activity against selected gram-positive and gram-negative bacteria. The biochemical characteristics of antimicrobial substances were investigated. The results indicated that the antimicrobial substances were still active after treatment with catalase and proteinase, respectively. Moreover, the stability of antimicrobial substances did not change after heat treatment at 40, 50, 60, 70 and 80°C for 30 min, respectively. The activity of antimicrobial substances remained stable at 4 and -20°C after long time storage. The antimicrobial activity of CFS was compared with that of the buffer with similar strength and pH. The inhibitory zone of the buffer was apparently smaller than that of CFS, which meant that the acid in CFS was not the only factor that was contributed to antibacterial activity of CFS. The antibiotic resistance and virulence potential were evaluated using disk diffusion test and PCR amplification. The results showed that E. faecium KQ 2.6 did not harbor any tested virulence genes such as gelE, esp, asa1, cylA, efaA and hyl. It was susceptible to most of tested antibiotics except for vancomycin and polymyxin B.
  
  
  CONCLUSIONS
  E. faecium KQ 2.6 may be used as bio-preservative cultures for the production of fermented foods.
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. Zhengwei27@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. Zhangy1987@126.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. luhuimin1993@126.com.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Lu
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. dantingl@126.com.
authors.forename: Dan-Ting
authors.initials: DT
authors.lastname: Li
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. ZhangZL64@126.com.
authors.forename: Zhi-Liang
authors.initials: ZL
authors.lastname: Zhang
authors.affiliation: College of Light Industry Science and Engineering, Nanjing Forestry University, 210037, Nanjing, Jiangsu, China. Tangzhenxing@126.com.
authors.forename: Zhen-Xing
authors.initials: ZX
authors.lastname: Tang
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, 310016, Hangzhou, Zhejiang, China. shilue@126.com.
authors.forename: Lu-E
authors.initials: LE
authors.lastname: Shi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001431:Bacteriological Techniques; D001688:Biological Products / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D016984:Enterococcus faecium / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D005243:Feces / Q000382:microbiology; D046094:Galliformes / Q000382:microbiology*; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D001688:Biological Products