Isolation And Identification Of Porcine Intestinal Bacteria And Respiratory Tract Bacteria

Porcine intestinal bacteria and respiratory tract bacteria play an important role inkeeping healthy for the host,which is also an important source of microbial.Isolationand identification of these bacteria is particularly important.Traditional identification ofbacteria include phenotypic characteristics,morphological observation, biochemicalreactions,serum agglutination and so on.These identification methods are widely usedin the monitoring of pathogens,but it has a lot of disadvantages while16SrRNA genesequence analysis method is sensitive,fast and high reliability,providing new ideas andmethods for identification.Thus,we identified porcine intestinal bacteria and respiratorytract bacteria using this technology.11bacteria were isolated from126porcine intestinal samples.One set of primerstargeting16SrRNA gene conserved were chosen to amplify certain fragments,PCRreaction and sequencing.Nucleotide sequences were compared with GenBankdatabase..The BLAST analysis and phylogenetic analysis indicated that A2and A4weremost similar to reported16S rRNA gene of Leuconostoc citreum,B2was most similar toreported16S rRNA gene of Lactobacillus murinus,C2was most similar to reported16SrRNA gene of Lactobacillus salivarius and the similarity>99%,F3was most similar toreported16S rRNA gene of Weissella paramesenteroides,F6and F7were most similar toreported16SrRNA gene of Weissella confusa,M3and M8were most similar to reported16S rRNA gene of Acinetobacter lwoffii,M9and M11were most similar to reported16SrRNA gene of Enterococcus faecalis.Susceptibility test results show that M8is sensitiveto amoxicillin,sulfadiazine,cephalosporins and other antibiotics but resistant tociprofloxacin,while M11is sensitive to linezolid,vancomycin but resistant toamoxicillin,erythromycin and ciprofloxac.82bacteria were isolated from176porcine lung tissue samples..Nucleotidesequences were compared with GenBank database..The BLAST analysis and phylogenetic analysis indicated that25bacteria were identified,including1Enterococcusfaecalis,2Moraxella,3Streptococcus suis,2Brevibacterium,6Planomicrobium,1Psychrotrophic,1Psychrobacter glacincola,1Aeroeoccus viridans,1Pseudomonas,3Bacillaceae and5Erysipelothrix rhusiopathiae.Bacillaceae belongs toprobiotics,Moraxella, Aeroeoccus viridans and Enterococcus faecalis belongs toconditional pathogenic, Streptococcus suis and Erysipelothrix rhusiopathiae belongs topathogens,while Planomicrobium,Psychrotrophic and Pseudomonas are new kings ofbacteria isolated from porcine. Growth curve of ER4and S7are accord with growth lawof bacteria.Mice Virulence experimental rusults indicates that ER4has strongpathogenicity.The16SrRNA gene sequence technology makes it possible to identify porcineintestinal bacteria and respiratory tract bacteria.We also get a lot ofprobiotics,conditional pathogenic,pathogens and new kinds of bacteria.Further researchfor biological characteristics of these bacteria will be studied.