Mechanism And Detection Of Heteroresistant Pseudomonas Aeruginosa

Objective:Nowadays,the number and drug resistance of Imipenem(short as IMP)-heteroresistant Pseudomonas aeruginosa are growing up with time.Pseudomonas aeruginosa(short as PA)hasbecome an important bacteria in nosocomial infection,and brings great misery and difficulty to clinical treatment.The mechanism of drug resistance of IMP is very complex and has not been fully elucidated,so it should be paid more attention to.In this program,we investigated the epidemiology,drug resistance and drug resistance mechanism of IMP in the district of changzhou in the past five years,and tried to provide early warning and assit in clinical treatment for the clinical prevention of nosocomial infection caused by the bacteria.To analyze the drug resistance of the IMP-heteroresistant PA in some areas of Changzhou for 5 years,to study the mechanism of resistance to the bacteria,to detect the disinfection effect of five common disinfectants in hospital,and to provide guidance for nosocomial infection control in hospital.Method:Detection and mechanism of drug resistance of IMP: spectrum analysis was used to calculate the frenquecy of bacteria resistance groups;double disc inhibitory synergy test was used to sift the metal beta lactamase phenotype;reverse transcription real-time quantitative PCR was used to check the bacteria active efflux system;crystal violet semi-quantitative test was used to detect the biofilms.PCR was used to detect the drug resistance gene.Disinfection effect research: neutralizing agent concentration test was used to make the neutralizer appraisal.The broth dilution method was used to test the minimum inhibitory concentration(short as MIC)and minimum bactericidal concentration(short as MBC).The suspension quantitative germicidal test was used to measure thee sterilization rate.Statistical method: the relevant data were processed and analyzed by X2 test and paired-samples T test.Result:The analysis of PA resistance in changzhou district showed that the detection rate of PA no decreased by month from 2013 to 2017.The number of sputum specimens and respiratory medicine specimens accounted for most.The highest rate of drug resistance was Piperacillin,28.1 % as well as the lowest rate was amikacin.The most serious type of drug resistance drug resistance is sputum specimens,and the most serious department of Terpene drug resistance is ICU.Among them,36 strains of IMP-heteroresistant,the highest number was still sputum specimens and respiratory medicine specimens,the highest resistance rate was piperacillin andlevofloxacin,the following were ciprofloxacin,ceftazidime and ticarcillin,carat acid,gentamicin,cefepime,amikacin,tobramycin,imp,piperacillin and tazobactam.The bacteria spectrum analysis suggested that the heterogeneity of PA for IMP heteroresistance mutation frequency is 8.9 x 10-7to 4.5x 10-9,resulting from the 36 strains in the hetero-resistant sifting tests.None MBL was produced by the PA of the 36 strains IMP heteroresistance,based on the result of Double disc inhibitory synergy test.The reverse transcription real-time quantitative PCR to detect the heterogeneity of 36 strains IMP resistant PA has high expression of efflux pump.The PA biofilm formation of of the 36 strains IMP resistant is detected significantly higher than the control group,in the crystal violet semi-quantitative experiments.We have found 6 strains lack OPRD 2gene and 3 strains carry qac E?1-sul1 gene through the PCR tests.During the antimicrobial susceptibility test,the IMP-heteroresistance PA is more sensitive to the three disinfectants,chlorine disinfectants,iodophor or ethyl alcohol,among the five kinds of common disinfectants(chlorine disinfectants,glutaraldehyde,iodophor,ethyl alcohol,and chlorhexidine in Hospital.Conclusion:The mechanism of drug resistance of 36 strains of IMP heteroresistance PA maybe related with the high expression of efflux pump?biofilm formation and the drug resistance gene.The three disinfectants,chlorine disinfectants,iodophor and ethyl alcohol shall be selected to disinfect bacteria in the hospital,in order to prevent the occurence and spead of nosocomial infection.