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CN-122012412-A - Phage composite preparation for vibrio harveyi and application

CN122012412ACN 122012412 ACN122012412 ACN 122012412ACN-122012412-A

Abstract

The invention relates to the technical field of microorganisms, in particular to a phage composite preparation aiming at vibrio harveyi and application thereof. The composite preparation comprises vibrio harveyi phage RDP-VB25018 with the preservation number of CGMCC No.46671 and vibrio harveyi phage RDP-VB25018R with the preservation number of CGMCC No. 46672. The compound preparation can effectively overcome the problem that bacteria are easy to generate resistance in phage treatment, has high-efficiency synergistic cracking effect on both the original strain and the resistant strain of Vibrio harveyi, has a cracking spectrum as wide as 84 percent, is far superior to single phage, and can crack one or more strains of Vibrio orientalis, vibrio harveyi, vibrio cholerae, vibrio compileicus, vibrio euvensis, vibrio alginolyticus and Vibrio parahaemolyticus. Animal experiments show that the compound preparation can obviously reduce the death rate of infected prawns from more than 85% to about 11%, and thoroughly remove pathogenic bacteria in tissues. The invention provides a high-efficiency and safe solution for the green prevention and control of the vibriosis of the aquatic products.

Inventors

  • DU XINYONG
  • LIU CHANGTAI
  • LIU YU
  • WANG TIANTIAN
  • SONG XINHUI

Assignees

  • 青岛润达生物科技有限公司

Dates

Publication Date
20260512
Application Date
20251226

Claims (10)

  1. 1. A phage composite preparation for vibrio harveyi is characterized by comprising vibrio harveyi phage RDP-VB25018 and vibrio harveyi phage RDP-VB25018R, wherein the vibrio harveyi phage RDP-VB25018 is preserved in China general microbiological culture Collection center for 8 months in 2025, the preservation numbers are CGMCC No.46671 respectively, and the vibrio harveyi phage RDP-VB25018R is preserved in China general microbiological culture collection center for 25 months in 2025, and the preservation numbers are CGMCC No.46672 respectively.
  2. 2. The phage composite preparation according to claim 1, wherein the titer of the phage RDP-VB25018 of Vibrio harveyi and the phage RDP-VB25018R of Vibrio harveyi is not lower than 10 10 PFU/mL.
  3. 3. The phage composite preparation for Vibrio harveyi according to claim 1, wherein the phage RDP-VB25018 of Vibrio harveyi has a burst period of about 120min and a burst amount of 340PFU/cell, and the phage RDP-VB25018R of Vibrio harveyi has a burst period of 110min and a burst amount of 460PFU/cell.
  4. 4. The phage composite preparation for vibrio harveyi according to claim 1, wherein the vibrio harveyi phage RDP-VB25018 and the vibrio harveyi phage RDP-VB25018R are maintained at 20-50 ℃ and the titer is maintained at 10 8 ～10 10 PFU/mL.
  5. 5. The phage composite preparation for vibrio harveyi according to claim 1, wherein the phage RDP-VB25018 and the phage RDP-VB25018R of vibrio harveyi are maintained at a pH of 5-10 and a titer of 10 6 PFU/mL or more.
  6. 6. The phage composite preparation according to claim 1, wherein the phage composite preparation can lyse one or more strains of Vibrio vibrio eastern, vibrio harveyi, vibrio cholerae, vibrio compilens, vibrio euvensis, vibrio alginolyticus, and Vibrio parahaemolyticus.
  7. 7. The phage composite preparation according to claim 1, wherein the cleavage rate of the phage composite preparation is not less than 84%.
  8. 8. The use of the phage composite preparation for vibrio harveyi according to claim 1 in the preparation of a medicament for preventing or treating vibrio harveyi infection.
  9. 9. Use of a phage composite formulation for vibrio harveyi according to claim 1 in the preparation of a formulation for controlling vibriosis in aquaculture.
  10. 10. The method of claim 8, wherein the agent is a water disinfectant or a culture environment improver.

Description

Phage composite preparation for vibrio harveyi and application Technical Field The invention relates to the technical field of microorganisms, in particular to a phage composite preparation aiming at vibrio harveyi and application thereof. Background Vibrio (Vibrio) is a typical representative of gram-negative bacteria, and is one of the common bacterial populations in marine environments, and is widely distributed in the sea areas such as bay, coast, estuary and the like. Vibrio species are various, and the main pathogenic bacteria include Vibrio harveyi (Vibrio harveyi), vibrio parahaemolyticus, vibrio alginolyticus, vibrio cholerae, etc. Along with the continuous expansion of the mariculture scale and the continuous increase of the culture density, the outbreak of the aquaculture diseases is frequent, and the occurrence scale of the aquaculture diseases is in an annual rising state. Vibrio harveyi is a common pathogenic bacterium in aquaculture, belongs to Vibrio of gamma-anamorphic vibrio, can cross species infection, is frequently used in spring and summer, and has higher detection rate in fish and shrimp products such as large yellow croaker, cynoglossus semilaevis, arca subcrenata, prawns and the like. The disease animals infected with vibrio harveyi often show body surface ulceration and hemorrhage, enteritis and ascites, scabies and the like, and can cause invertebrate to have acute hepatopancreatic necrosis and leukoplakia. Meanwhile, vibrio harveyi is an opportunistic pathogen for people and livestock, and infection of Vibrio harveyi in marine environment can cause diarrhea, abscess, septicemia and necrotic wound infection of human beings, and cause serious inflammatory reaction. At present, prevention and control of vibriosis mainly dependent on strategies such as antibiotic treatment, vaccine immunization, probiotic application and the like. However, antibiotic abuse is prone to the emergence of multi-drug resistant strains, vaccine protection rates are limited by serotype diversity, and control effects exhibit regional differences, severely limiting the application effects of traditional strategies. Therefore, development of non-antibiotic prevention and control strategies based on biological control and ecological regulation is particularly necessary. Phage therapy is an effective measure for reducing antigen, and the screening operation of natural phage is complex and time-consuming, and it is difficult to efficiently isolate phage strains with the ability to lyse bacteria. Meanwhile, the rapid evolution of phage resistance mechanisms can enhance the phage resistance of host bacteria, and bacteria develop resistance through mutation (such as changing cell surface receptors, obtaining CRISPR-Cas and other immune systems), so that the effectiveness of phage as an antibacterial drug is weakened. If only a few phages are relied upon, resistant bacteria will rapidly dominate, resulting in treatment or prevention failure. Isolation of new phages that infect these resistant bacteria is a direct means of restoring and maintaining control effects. In order to rapidly destroy pathogenic bacteria and delay the development of phage resistance, phage cocktail therapy using multiple phage combinations can be used to improve the therapeutic effect of phage therapy. Phage cocktail therapy can more effectively cope with infections with multiple resistant bacteria than single phage therapy and significantly reduce the probability of pathogenic bacteria developing phage resistance. However, the conventional cocktail is mostly prepared by simply mixing phages from different sources, and the synergism, broad spectrum and the capability of removing resistant strains of the combination have great contingency, and an active and efficient design strategy is lacked to construct phage combinations capable of predicting and overcoming the problem of bacterial resistance. Therefore, the development of a phage composition that can actively cope with phage resistance development, has a clear synergistic effect and a broader lytic spectrum is of great importance for the practical application of phage therapy in aquaculture. The above information disclosed in this background of the application is only for enhancement of understanding of the background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a phage composite preparation which has a synergistic antibacterial effect on vibrio harveyi and can effectively lyse original vibrio harveyi and phage resistance mutant strains thereof and application thereof. The technical scheme of the invention is as follows: In one aspect, a phage composite preparation for vibrio harveyi comprises vibrio harveyi phage (Vibrio harveyi bacteriophage) RDP-VB25018