The Infection State Of Pseudomonas Aeruginosa In Hengyang And Its Resistance Mechanisms To Carbapenems

Objective: To get the statistical analyses results of clinical distribution and drugresistance of Pseudomonas aeruginosa in Hengyang district, research the resistancemechanisms of Pseudomonas aeruginosa on carbapenem antibiotics, which expect toprovide the rational clinical basis for using antimicrobial drugs in infectious diseases.Methods: Isolated, cultured and identificated796clinical isolates of Pseudomonasaeruginosa which come from the First Affiliated Hospital of University of SouthChina, the Second Affiliated Hospital of University of South China, the AffiliatedNanhua Hospital of University of South China and the Central Hospital of Hengyang,and performed drugs susceptibility testing for Pseudomonas aeruginosa using19kinds of antimicrobial drugs, To get the statistical analyses results of clinicaldistribution and drug resistance of Pseudomonas aeruginosa in Hengyang district.Furthermore, we selected54carbapenem-resistant Pseudomonas aeruginosa to detectthe distribution of β-lactamase coding genes (IMP, VIM, OXA, SPM, TEM, PER,GES and SHV) using PCR, and detected the expressionof OprD2using Western Blot,in order to investigate the antibiotic resistance and its molecular mechanism ofPseudomonas aeruginosa in Hengyang district.Results: In the796strain Pseudomonas aeruginosa, most come from sputum,accounting for64.32%(512/796), followed by wound secretion, accounting for9.05%(72/796). While in endemic area, most come from ICU department, accounting for14.07%(112/796); followed by neurosurgery and respiratory department, accountingfor9.05%(72/796). In the result of susceptibility testing of19kinds of drugs, morethan50%resistance rate reached13kinds (68.42%), the highest rate of drug-resistantis ampicillin/sulbactam (98.00%), followed by co-trimoxazole (95.00%) andticarcillin (79.00%), the lowest rate of drug-resistant is polymyxin E (8.00%). We Selected54carbapenem-resistant Pseudomonas aeruginosa to detect the β-lactamasegene using PCR, the results show that there are28strain IMP-positive,18strain areVIM-positive, the IMP-positive and VIM-positive both are6strain, there are2strainare OXA-positive, the other β-lactamase gene (SPM, TEM, PER, GES, SHV) arenegative, There are4in54strain Pseudomonas aeruginosa missing outer membraneprotein OprD2.Conclusions:(1) Clinical isolates of Pseudomonas aeruginosa most come from respiratoryspecimens, While in endemic area, most come from ICU, neurosurgery andrespiratory department, and drug resistance is very serious.(2) The carbapenem antibiotic resistance of Pseudomonas aeruginosa in Hengyangdistrict are major relate to β-lactamase gene IMP and VIM.(3) The missing of outer membrane protein OprD2may not be main mechanism ofcarbapenem-resistant of Pseudomonas aeruginosa in Hengyang district.