表达抗菌肽BMAP-BSN的重组乳酸菌对沙门氏菌感染雏鸡肠道菌群的影响

摘要沙门氏菌是一种常见的食源性致病菌，容易感染雏鸡，而感染病鸡又常常作为传染源，加剧对公共卫生与养殖业的威胁。抗生素预防虽然有效，但容易引起沙门氏菌耐药，造成环境污染等问题。抗菌肽BMAP18和BSN37具有广谱抗菌功能，对沙门氏菌抗菌效果显著，但是其生产制约其发展。利用工程乳酸菌表达抗菌肽有望实现抗菌并调节肠道微生态的目标，成为替代抗生素的潜在策略。本研究以表达抗菌肽BMAP18-BSN37的重组乳酸菌NZBB为研究对象，建立雏鸡沙门氏菌感染模型，评估NZBB对沙门氏菌感染雏鸡肠道菌群的影响。构建感染模型后，通过16SrRNA基因高通量测序技术分析雏鸡盲肠内容物第5天和第7天的肠道菌群结构变化。测序结果显示，Alpha多样性指标中Shannon指数和Simpson指数上升，提示重组乳酸菌对肠道菌群的影响优于野生菌株，而Beta多样性分析中，PcoA、NMDS的分析结果显示NZBB组干预沙门氏菌感染后，雏鸡肠道菌群的结构向对照组靠近。菌群差异分析显示，在NZBB组中，有益菌Bacteroides的丰度显著上升，而潜在有害菌Mediterraneibacter的丰度显著下降。综合研究结果显示，沙门氏菌感染会导致雏鸡肠道菌群的多样性下降，致病菌的丰度增加，而通过NZBB干预感染后能够缓解菌群失调的现象。本研究为绿色、安全的抗菌新策略提供了理论依据，也为后续研究提供了新思路，具有重要的研究价值。关键词：BMAP18-BSN37；重组乳酸菌；沙门氏菌；肠道菌群AbstractSalmonellaisacommonfoodbornepathogen,whichiseasytoinfectchickens,andinfectedchickensareoftenusedasthesourceofinfection,whichaggravatesthethreattopublichealthandbreedingindustry.Althoughantibioticpreventioniseffective,itiseasytocauseSalmonellaresistanceandenvironmentalpollution.AntimicrobialpeptidesBMAP18andBSN37havebroad-spectrumantibacterialfunctionsandhavesignificantantibacterialeffectsonSalmonella.Theuseofengineeredlacticacidbacteriatoexpressantimicrobialpeptidesisexpectedtoachievethegoalofantibacterialandregulatingintestinalmicroecology,andhasbecomeapotentialstrategytoreplaceantibiotics.Inthisstudy,recombinantlacticacidbacteriaNZBBexpressingantimicrobialpeptideBMAP18-BSN37wasusedastheresearchobjecttoestablishamodelofSalmonellainfectioninchickensandevaluatetheeffectofNZBBontheintestinalfloraofSalmonella-infectedchickens.Aftertheinfectionmodelwasconstructed,thechangesofintestinalflorastructureincecalcontentsofchicksonthe5thand7thdayswereanalyzedbyhigh-throughputsequencingof16SrRNAgene.ThesequencingresultsshowedthattheShannonindexandSimpsonindexintheAlphadiversityindexincreased,suggestingthattheeffectofrecombinantlacticacidbacteriaontheintestinalflorawasbetterthanthatofwildstrains.IntheBetadiversityanalysis,theanalysisresultsofPcoAandNMDSshowedthatthestructureoftheintestinalfloraofthechicksintheNZBBgroupwasclosetothecontrolgroupaftertheinterventionofSalmonellainfection.FloradifferenceanalysisshowedthatintheNZBBgroup,theabundanceofbeneficialbacteriaBacteroidesincreasedsignificantly,whiletheabundanceofpotentiallyharmfulbacteriaProteobacteriadecreasedsignificantly.TheresultsofcomprehensiveresearchshowedthatSalmonellainfectioncoulddecreasethediversityofintestinalfloraandincreasetheabundanceofpathogenicbacteriainchicks,whileNZBBinterventioncouldalleviatetheimbalanceofintestinalflora.Thisstudyprovidesatheoreticalbasisforanewgreenandsafeantibacterialstrategy,andalsoprovidesanewideaforsubsequentresearch,whichhasimportantresearchvalue.Keywords:BMAP18-BSN37,Recombinantlacticacidbacteria,Salmonella,Intestinalflora.目录前言 [20]。本研究中重组乳酸菌干预组菌群结构趋于稳定，并表现出一定的抗感染效果，进一步支持肠道微生态在病原防控中的关键作用。4结论本文围绕表达抗菌肽BMAP18-BSN37的重组乳酸菌对沙门氏菌感染雏鸡肠道菌群的影响展开