title: Antibacterial activity of chitosan against Aeromonas hydrophila.
abstract: The effect of chitosan on growth and production of haemolysin by Aeromonas hydrophila was investigated as well as the effects of temperature, pH, salts and irradiation on the antibacterial activity of chitosan. It was found that chitosan affected growth and haemolysin production of A. hydrophila in varying degrees compared to the control. Growth and haemolysin production were clearly suppressed at 0.04% of chitosan. Suppression was more effective at pH 6.0 than at pH 7.0. The bactericidal effects of chitosan increased with increasing temperature and decreasing pH. Divalent cations at concentrations of 10 and 25 mM reduced the antibacterial activity of chitosan, in the order of Ba2+ > Ca2+ > Mg2+. Sodium ions at concentrations of 10 and 25 mM also reduced chitosan's activity. Irradiation of chitosan at 150 kGy under dry condition was effective in slightly increasing its activity.
authors.affiliation: National Center for Radiation Research and Technology, Microbiology Department, P.O. Box 29, Nasr City, Cairo, Egypt. shabantaha@yahoo.com
authors.forename: Shaban M A
authors.initials: SM
authors.lastname: Taha
authors.forename: Hesham M H
authors.initials: HM
authors.lastname: Swailam
mesh_terms: D016980:Aeromonas hydrophila / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000528:radiation effects; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects; D048271:Chitosan; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D014783:Viscosity / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; D006460:Hemolysin Proteins; D002686:Chitin; D048271:Chitosan