title: In vitro inhibitory effect of hen egg white lysozyme on Clostridium perfringens type A associated with broiler necrotic enteritis and its alpha-toxin production.
abstract: OBJECTIVE
  Clostridium perfringens type A causes both clinical and subclinical forms of necrotic enteritis in domestic avian species. In this study the inhibitory effect of hen egg white lysozyme on the vegetative form of Cl. perfringens type A and the production of alpha-toxin in vitro was investigated.
  
  
  RESULTS
  A micro-broth dilution assay was used to evaluate the minimal inhibitory concentrations (MIC) of lysozyme against three clinical isolates of Cl. perfringens type A in 96-well microtitre plates. The MIC of lysozyme against Cl. perfringens isolates was found to be 156 microg ml(-1). Scanning electron micrographs of the cells treated with 100 microg ml(-1) of lysozyme revealed extensive cell wall damage. A quantitative sandwich ELISA for alpha-toxin produced by Cl. perfringens was developed based on a commercial ELISA kit allowing only qualitative detection. Addition of 50 microg ml(-1) of lysozyme did not inhibit the growth of Cl. perfringens but significantly inhibited the toxin production.
  
  
  CONCLUSIONS
  Lysozyme inhibited the growth of Cl. perfringens type A at 156 microg ml(-1). At sublethal levels, lysozyme was able to inhibit the alpha-toxin production.
  
  
  CONCLUSIONS
  Inhibition of Cl. perfringens type A and its alpha-toxin production by hen egg white lysozyme had never previously been reported. By inhibiting this avian pathogen and its toxin production, lysozyme showed potential for use in the treatment and prevention of necrotic enteritis and other Cl. perfringens type A related animal diseases.
authors.affiliation: Inovatech Bioproducts, Abbotsford, BC V2T 6K8, Canada. jzhang@inovatech.com
authors.forename: G
authors.initials: G
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Darius
authors.forename: S R
authors.initials: SR
authors.lastname: Smith
authors.forename: S J
authors.initials: SJ
authors.lastname: Ritchie
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology*; D003015:Clostridium Infections / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary; D003016:Clostridium perfringens / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D004529:Egg White; D020345:Enterocolitis, Necrotizing / Q000382:microbiology* / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009113:Muramidase / Q000494:pharmacology*; D010738:Type C Phospholipases / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D010738:Type C Phospholipases; C421864:hen egg lysozyme; D009113:Muramidase