China Animal Husbandry and Veterinary Medicine ›› 2024, Vol. 51 ›› Issue (1): 278-291.doi: 10.16431/j.cnki.1671-7236.2024.01.028

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Evaluation of the Prevention and Therapeutic Effect of Lytic Bacteriophage KM104 on Different Serotypes of Salmonella spp.from Chickens

CHEN Liyin1,2, PENG Yating1,2, YAN Hongya1, CHEN Peifu2, XIN Aiguo1, LI Ke1   

  1. 1. Poultry Husbandry and Disease Research Institute, Yunnan Academy of Animal Husbandry and Veterinary Sciences, Kunming 650224, China;
    2. College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
  • Received:2023-06-28 Online:2024-01-05 Published:2023-12-27

Abstract: 【Objective】 This study was to investigate the preventive and therapeutic effects of lytic phage KM104 strain on Salmonella spp.infection in chickens with different serotypes.【Method】 In this experiment the in vitro lysis spectrum and in vivo safety of KM104 strain and the attack dose and the multiplicity of infection were determined.According to the time, frequency and concentration for use of the bacteriophage KM104 strains, the prevention and therapeutic models of Salmonella spp.infection from chickens with three different serotypes in White feather laying hens were constructed.By recording the survival number and survival rate, growth performance, clinical symptoms and pathological changes of test animals and measuring bacterial excretion of anal swab, bacterial load of spleen and organ index, the prevention and therapeutic effect of KM104 was comprehensively evaluated.【Result】 The cleavage rate of the bacteriophage KM104 in five serotypes of Salmonella spp.was 80.65% (50/62), in vitro it had good bacteriostatic effect and had no obvious pathogenic effect on chickens were found.The best treatment method:The therapeutic doses for Salmonella Pullorum, Salmonella Gallinarum and Salmonella Enteritidis were 7.96×107, 1.26×104 and 1.68×107PFU/mL, respectively, and the survival rate of chicks was the highest (90%, 80% and 90%) by continuous feeding with high titer phage KM104 for 3 days.Compared with the untreated control group, it could effectively alleviate the clinical symptoms and organ damage of experimental chicks, and the weight gain increased significantly (P<0.05), and the bacterial excretion of anal swab, the bacterial load of spleen and organ index decreased significantly (P<0.05).【Conclusion】 Bacteriophage KM104 had broad-spectrum lytic activity against pathogenic Salmonella spp.of multiple serotypes, and had no obvious pathogenic effect on chickens were found.The method of feeding KM104 with high titer for 3 days before bacteria attack had the best preventive effect on chickens from being infected with Salmonella Pullorum, Salmonella Gallinarum and Salmonella Enteritis, and could thus be used for the development of Salmonella spp. biocontrol preparations.

Key words: Bacteriophage; lysis spectrum; Salmonella; chicken

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