Microbiology
Mohammad Pourahmadi; Kimia Pourahmadi; Farzan Modaresi; Shekoufeh Atashpoor; Azita Azad; Alireza Ranjbaran; Abdolmajid Ghasemian
Abstract
Background & Objective: The spread and development of drug-resistant bacterial strains has prompted the hunt for novel antibacterial polypeptides undergoing conformational changes to confer rapid bactericidal effects. The aim of this study was to evaluate the effect of novel BMAP27-Melittin conjugated ...
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Background & Objective: The spread and development of drug-resistant bacterial strains has prompted the hunt for novel antibacterial polypeptides undergoing conformational changes to confer rapid bactericidal effects. The aim of this study was to evaluate the effect of novel BMAP27-Melittin conjugated peptide- nanoparticle (NP) against Streptococcus mutans as the primary pathogen from subgingival plaques.Methods: Sixty subgingival plaque samples were collected, and 39 S. mutans isolates were identified. The BMAP27-Melittin conjugated peptide was purchased from GenScript Company, USA. Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Biofilm Inhibitory Concentration (BIC), and Biofilm Eradication Concentration (BEC) of BMAP27-Melittin-NP were calculated using the microtiter method.Results: Thirty-nine infected subjects were reported, including 24 males and 15 females (P=0.299). MIC, MBC, BIC, and BEC of BMAP27-Melittin–NP against S. mutans were 1.8, 2.9, 2.1, and 3.8μg/mL, respectively. The mean MBC, BEC, and BIC values were significantly lower among clinical isolates than S. mutans ATCC 35688 standard strain (P=0.032, 0.001, and 0.001, respectively).Conclusion: BMAP27-Melittin-NP demonstrated significant antibacterial and anti-biofilm effects against clinical isolates of S. mutans which can be considered a promising compound to prevent or treat dental caries and eradicate the oral infections.
Mahboubeh Mirhosseini; Fatemeh Barzegari Firouzabadi
Abstract
Background & Objectives: Direct addition of antimicrobial materials to food during food processing is an effective method for controlling microbial contaminants of food and extending the shelf-life of food products. Objective of this research was to study the antimicrobial effect of zinc oxide (ZnO) ...
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Background & Objectives: Direct addition of antimicrobial materials to food during food processing is an effective method for controlling microbial contaminants of food and extending the shelf-life of food products. Objective of this research was to study the antimicrobial effect of zinc oxide (ZnO) nanoparticle and potential applications of ZnO nanoparticles in terms of controling two food-borne pathogens in milk. Methods: Toxicity of different concentration (0, 0.5, 2, 5, and 10 mM) of ZnO nanoparticles on Listeria monocytogenesand Bacillus cereuswas studied in culture media and milk. Results: Among the mentiond concentrations, treatment of 10 mM of ZnO nanoparticle was the most effective one for L. monocytogenesand B. cereus inhibition, which completely inhibited the growth ofL. monocytogenesand B. cereusin 24h. These data revealed concentration-dependency of the antibacterial activity of ZnO. Therefore, 5 mM and 10 mM ZnO were selected for further studies, which were performed in milk, since they demonstrated significant growth inhibition. ZnO NPs were more capable in terms of reducing the initial growth counts of all the above-stated strains in milk. Conclusion: ZnO nanoparticles had an antimicrobial activity against L. monocytogenes and B. cereusin milk and the media. This work was a preliminary study that provided a starting point for determining whether the use of ZnO nanoparticles had the potential for being applied in food preservation or not.
