Chicken Foodborne Enteritidis Salmonella Phage:Isolation,Identification,and Biological Properties

Diseases caused by foodborne pathogens have become an important issue that threatens global food hygiene and security,and sanitation.Salmonella is a globally prevalent foodborne pathogen.And Salmonella enteritidis causes extremely common adverse events.As the resistance of most bacteria to different kinds of antibacterial drugs becoming increasingly serious,human beings will encounter the dilemma that there will be no drugs could help in the near future-"post-antibiotic era",while chemical or physical sterilization methods affect the quality of food most times.Thus,biological control techniques of Salmonella have become a hot research topic recently.In this experiment,authors first isolated Salmonella from chicken.Then,the drug-resistant Salmonella isolated from chicken was used as the inducer to isolated phage from chicken slaughterhouse effluent.Authors revealed biological properties of Salmonella enterica in foods,more importantly,we provide theoretical basis for biological prevention and control of Salmonella enterica in foods,and meat fresh-keeping in the industry.The main findings are as follows:1.Isolation and identification of Salmonella from chicken.Authors collected 39 chicken samples from Handan area,and utilized conventional bacterial isolation and identification approaches and 16 S r DNA molecular bioassay techniques to detach five strains of Salmonella stem from chicken from multiple resources.Kirby-Bauer method was adopted to test the drug resistance test of five strains of chicken-origin Salmonella.Results revealed that five strains of chicken-origin Salmonella were resistant to 11 drugs commonly used in veterinary clinics,and three of these five strains were severely resistant.2.Isolation and purification of Salmonella phage.Using conventional isolation and purification methods,authors isolated two strains of Salmonella phage from the effluent of a chicken slaughterhouse and observed Salmonella phage by transmission electron microscopy.Through the morphological identification process,authors found that two strains of Salmonella phage isolated from the effluent of a chicken slaughterhouse were members of Siphoviridae,and shared the morphological and structural characteristics of virulent Salmonella phage.3.Study of biological properties of Salmonella phage.Authors used conventional methods to detect the biological properties of Salmonella phage,and found that the optimal infection complex for phage S2 was 0.01;the optimal infection complex for phage S4 is 0.001;phage S2 had lower level of lysis rate and thermal stability than phage S4;both phage S2 and S4 had short latency and high lysis ability.Similar to the case of most phages,both phage S2 and phage S4 were tolerant to high temperatures.Additionally,phage S4 was more tolerant to high temperature than phage S2.Both phage S2 and phage S4 showed resistance to bases but not to strong acids.In summary,authors isolated Salmonella enterica phage(S2 and S4)of good biological properties from slaughterhouse effluent of chickens,using multi-drug resistant Salmonella of chicken origin as the inducing bacteria,with the bilayer plate method adopted.More importantly,its good biological properties provide theoretical support not only for the development and application of Salmonella phage resources,for biological prevention and control of foodborne Salmonella,but also for meat fresh-keeping in the industry.Authors believe that the current research is very worthy in industry and anticipate that it has bright prospects.