title: Optimization of sporicidal activity and environmental Bacillus endospores decontamination by biogenic silver nanoparticle.
abstract: OBJECTIVE
  The intent of this study is to decontaminate Bacillus endospores and to determine the D-values using silver nanoparticles (AgNPs) synthesized from Streptomyces sp. cell filtrate.
  
  
  METHODS
  AgNPs synthesis was performed extracellularly followed by characterization using spectrophotometer, High Resolution Transmission Electron Microscope and x-ray diffraction pattern analysis. Subsequently, the optimized conditions for the decontamination and D-value estimation of Bacillus endospores were determined using the response surface methodology. The environmental spore decontamination study was performed in mice model.
  
  
  RESULTS
  AgNPs were visibly and spectroscopically identified which were spherical with the size range of less than 20 nm. The synthesized AgNPs destroyed 1log10 CFU Bacillus endospores at around 20 min. The adherence of AgNPs to the surface of spore coat, pit formation and its complete structural loss was detected under field emission scanning electron microscopy. All the mice exposed to AgNP-treated spores showed no sign of pathological lesions.
  
  
  CONCLUSIONS
  The results of our study strongly suggest that the application of AgNPs as a sporicidal agent could be a new approach in consistently eliminating the hazardous Bacillus spores.
authors.affiliation: 1Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Ponnusamy M
authors.initials: PM
authors.lastname: Gopinath
authors.affiliation: 1Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Dharumadhurai
authors.initials: D
authors.lastname: Dhanasekaran
authors.affiliation: 1Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Anandan
authors.initials: A
authors.lastname: Ranjani
authors.affiliation: 1Department of Microbiology, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Nooruddin
authors.initials: N
authors.lastname: Thajuddin
authors.affiliation: 2Mahatma Gandhi-Doerenkamp Center for Alternatives to the Use of Animals in Life Science Education, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Mohamad A
authors.initials: MA
authors.lastname: Akbarsha
authors.affiliation: 3Department of Biomedical Science, Bharathidasan University, Tiruchirappalli 620 024, Tamil Nadu, India.
authors.forename: Meganathan
authors.initials: M
authors.lastname: Velmurugan
authors.forename: Annamalai
authors.initials: A
authors.lastname: Panneerselvam
mesh_terms: D000818:Animals; D001407:Bacillus / Q000187:drug effects*; D004195:Disease Models, Animal; D004202:Disinfectants / Q000302:isolation & purification / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004783:Environmental Microbiology; D016908:Gram-Positive Bacterial Infections / Q000473:pathology; D051379:Mice; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D012834:Silver / Q000302:isolation & purification / Q000494:pharmacology*; D013053:Spectrophotometry; D013171:Spores, Bacterial / Q000187:drug effects*; D013302:Streptomyces / Q000378:metabolism; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D004202:Disinfectants; D012834:Silver
keywords: Bacillus endospores; D-value; Streptomyces sp.; response surface methodology; silver nanoparticles; sporicidal agent