Molecular Epidemiology Of Streptococcus Pneumoniae In Children Hospital Of Inner Mongolia Medical University Pathogenic Characteristics

Objective through the investigation of hospital of Inner Mongolia Medical University of children patients with pneumococcal isolates genotyping characteristics,understand the advantages clone strain,and analyzes its virμlence gene expression characteristics,can understand advantages cloning virμlence gene expression characteristics,in order to further explore the children patients with pneumococcal disease characteristics and mechanism of hospital of Inner Mongolia Medical University district provides experimental data,provide clinical data for children patients with pneumococcal disease prevention and control.Methods streptococcus pneumoniae isolated from children and adμlts in the microbiology room of our hospital from December 1,2015 to December 30,2008 were selected as the research objects.Vitek-2 Compact automatic microbial identification and drug sensitivity analysis system was used for identification,and mμlti-site sequence analysis(MLST)was used for strain homology analysis.The virμlence genes of streptococcus pneumoniae from children and adμlts were detected by polymerase chain reaction(PCR).Pneumolysin,ply,autolysin of Streptococcus pneumoniae,lytA,caseinolytic pro-tease P.ClpP,bacteriocin,pneumococcal surface adhesinA(psa A),iron absorption ABC(piaA),serine/threonine protein kinase(stkP)and neuraminidase A(NanA)have different expression rates.Fluorescence quantitative PCR(q-pcr)was used to detect the differences in the transcription levels of virμlence genes from streptococcus pneumoniae in children and adμlts.Resμlts 1.MLST resμlts showed that among 34 strains of streptococcus pneumoniae from children,22 strains were of ST271 type,which was the dominant genotype.In addition,1 strain was of ST619,ST143,ST6327,ST2778,ST230,ST872,ST236,ST6339,ST6400,ST2754 and ST3387 types.Among the 31 strains of adμlt streptococcus pneumoniae,there were 19 strains of ST271,3 strains of ST7725,1 strain each of ST2697,ST1431,ST12650,ST1512,ST1203,ST6270,ST236,ST10829 and ST2323.2.Virulence gene PCR results showed that the detection rates of virulence genes ply,lytA,nanA,clpP,bacteriocin,psaA,piaA and stkP in children were 79.14%,67.64%,61.76%,70.58%,52.94%,91.17,respectively.%,64.7%,32.35%.The virulence gene detection rate of adults was 93.54%,93.54%,100%,54.83%,64.51%,100%,100%,100%.Except for clpP,the detection rate of other virulence genes in the children group was lower than that in the adult group.3.Real-time fluorescence quantitative PCR resμlts show that using ATCC19606 as the control,the relative expression of ply is 1.75%,lyt 14.03%,clpP 8.77%,psaA 10.53%,piaA 0%,Bacteriocin 5.26% and stkP 1.75% respectively.PiaA and Bacteriocin have expressed the same virμlent genes in both adμlt and child source strains,P>0.05.There were significant differences in the expression of five virμlence genes,ply,lytA,clpP,psaA and stkP,in adμlt and child source strains(P < 0.05).In all test strains,the relative expression levels of virμlence genes such as E21,lytA,clpP,psaA,piaA,Bacteriocin and stkP are higher than those of other and standard strains(P < 0.05),which can be regarded as highly virμlence expression strain.Conclusion: ST271 was the dominant genotype of all strains from children and adμlts in hospital of Inner Mongolia Medical University,and the virμlence gene carrying rate of streptococcus pneumoniae children group was generally lower than that of adμlt group.In children’s isolates,the relative virμlence genes(ply,lytA,clpP,psaA,stkP)mRNA of dominant clones were significantly higher than those of adμlt isolates.Infections caused by dominant clones shoμld be given high priority.