Research On The Mutant In 23SrRNA Of Ureaplasma Urealyticum Resistant To Macrolide Antibiotic

Objectivemycoplasma ,an important pathogeny of genitourinary tract , is getting more more attention ,while the incidence of the disease raises year after year.The rate of infection caused by Ureaplasma urealyticum(Uu) is more than 90%.Because of the undefined use of antibiotics ,the clinical strains showed more phenotype of resistance to antibiotics commonly used , especially to macrolides.The purpose of this subject is to investigate the relationship of Ureaplasma urealyticum acquired resistance to Macrolide antibiotics and the mutant in the 23S rRNA.MethodsUrogenital specimens from 108 outpatients were assayed in parallel by the two mediums, then to compare the results.Choose 14 strains with the commonly phenotype of acquired resistance to macrolide as the detected strains.Compare the sequence 2050-2620 in 23S rRNA of the 14 serotypes known of Uu using MB Advanced DNA Analysis 6.83 software.Design specific primer aimed of 2050 to 2620 in 23SrRNA using software primer premier 5.0.PCR was performed to amplify the purpose region ,then the product is purified for sequencing.Comparing the sequence of the products with corresponding sequence in genbank ,analysis the mutant and the relationship between the genetype and the phenotype.ResultsThe result of comparison of culture mediums for detection of mycoplasma is that considering the typical colony on the solid medium as the standard evidence of the mycoplasma infection ,37 cases were positiveby the solid culture,41 cases were positive by the liquid culture.Only 26 positive cases do the liquid culture medium give the correct diagnosis.In all ,89 cases including negative have the same result on the two mediums.In the mutant detection,9 strains with the phenotype of acquired high resistance to Roxithromycin(ROX) and midrange resistance to Azithromy- cin(AZI) have the same sequences with the Ureaplasma Parvum. The C2243N( T or C) transition was found in the 23S rRNA sequence of 5 strains with the phenotype of high resistance to Roxithromycin(ROX) and Azithromycin(AZI).ConclusionsC-N( T or C) at position 2243 in 23SrRNA of Uu may be associated with high resistance to Azithromycin(AZI) , a kind of 15-ring Macrolide Antibiotics.The concrete correlation still needs farther study.