| Objective:This study investigated the antimicrobial use and microbial resistance of our hospital on October 16,2019 at 8:00,and to find if there are problems with our hospital's antimicrobial use.Further study the resistance mechanism of Multi-drug resistance Pseudomonas aeruginosa?MDRPA?in our hospital.To explore the optimal combined treatment plan for MDRPA,and provide theoretical basis for clinical MDRPA treatment plan.1.Point prevalence survey of antimicrobial use in this hospital Method:?1?Survey method:Investigate the antibacterial use in 9 clinical departments of the Second Hospital of Shanxi Medical University at 8:00 on October 16,2019.Screening for the use of antibacterial with all hospitalized patients at the selected department.All hospitalized patients were the survey denominator,patients who were using antibacterial at that time,patients with acquired infections who did not use antimicrobials and patients with surgical antimicrobial prophylaxis were the specific investigators.?2?Survey contents:?1?Investigate the basic information of patients;?2?Investigate the use of antibacterial in the department?the usage and dosage of all non-locally used antibacterial and the route of administration,infection diagnosis and medication indications?;?3?Usage and dosage of antibacterial drugs for surgical prevention and medication course;?4?Quality evaluation of antibacterial use;?5?Nosocomial infection;?6?Microbiological examination.?3?Statistical analysis:Data analysis adoption rate,composition ratio,etc.The chi-square test,the independent sample T test the univariate analysis and the binary logistic regression model was used.Result:?1?Investigation of the antibacterial use on the investigation day:A total of 525inpatients were included in this study.54.10%of patients used at least one antibacterial,and the use rate of antibacterial drugs in the medical ward was higher than that in the surgical ward?P=0.013?.The patients with a single antibacterial agent alone accounted for 42.96%.Patients who used more than one antibacterial drug?combined medication?accounted for 57.04%,and the ratio of combined medication in the medical ward was much higher than that in the surgical ward?P=0.001?.A total of 284 patients received 441 prescriptions for treatment.The vast majority of prescriptions prescribed are for the treatment of community-acquired infections?89.34%?.The number of prescriptions for empirical treatment is much higher than the number of prescriptions for target treatment.In this survey,the number of pneumonia or lower respiratory tract infections was the highest?49.43%?.The most commonly used antibacterial were piperacillin and sulbactam?18.26%?,etimicin?16.26%?,and moxifloxacin?10.47%?.?2?Evaluation of the quality of antibacterial:The records of withdrawal/review of antibacterial were poor?46.03%?.Records of the reasons for diagnosis and treatment during the course of disease were good?84.13%?.The overall guideline compliance rate was 77.32%.?3?The use of antibacterial for surgical prevention:There were 55 surgical patients with antibacterial for preventive use in this study.The type?surgical incision was the most?71.93%?.The most commonly used antibacterial for surgical prevention are the third-generation cephalosporins and their enzyme inhibitor inhibitors?45.61%?.The first generation of cephalosporin antibacterial drugs ranked second?21.05%?,and the total of other types of antibacterial drugs accounted for 33.34%.?4?Quality evaluation of antibacterial drugs for surgical prevention:The guideline compliance rate is only 70.00%.In terms of the medication course,70.18%of the prescriptions are prescribed for more than one day,and 19.3%of the prescriptions are prescribed for one day.Single-dose prescriptions only accounted for 10.53%.?5?Analysis of risk factors of hospital-acquired infection:The results of univariate analysis showed that surgical operations,indwelling catheters,and respiratory intubation in our hospital were all risk factors for hospital-acquired infections?P<0.1?.Multivariate logistic regression analysis showed that surgery in our hospital was the only risk factor for hospital-acquired infection on the day of the investigation.The incidence of hospital acquired infection during surgery in our hospital was 6.58 times than that without surgery.?6?Microbiological detection and drug sensitivity results:A total of 85 strains of bacteria were isolated.Sputum specimens accounted for 63.53%.Most of the isolates came from the department of intensive care unit?27.06%?,the department of respiratory medicine?23.53%?and the department of neurosurgery?22.35%?.The first four were Gram-negative bacteria,and the multidrug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii were 70.59%and 40.00%,respectively.2.Drug resistance mechanism of clinically isolated multidrug-resistant Pseudomonas aeruginosa.Method:?1?Strain collection and identification:30 non-repetitive MDRPA strains isolated from each clinical department of a hospital were collected.All have been identified by BioMérieux VITEK-2.Together with PAO1 constitute the experimental strain of this study.?2?PCR amplification target genes:Resistance genes[SHV,IMP,TEM,CTX-M1,kpc,OXA-48,oprD2,ant?3'?-?,aac?6'?-?,mcr-1,gyrA,gyrB,parC,parE]was amplified by PCR.The DNA product was directly sequenced.?3?Quantitative real-time PCR:MexA,MexC,MexE,and MexX genes are used as the target amplification genes,and gene GADPH is used as the reference gene.RT-PCR is used for amplification and quantification.Calculate the relative expression of target genes of experimental strains based on CT values?4?Statistical analysis:Snapgene software was used to compare the base and amino acid mutations of PAO1.The comparative analysis uses the chi-square test,and the correlation analysis uses the Pearson correlation coefficient?r?.Result:?1?Sensitivity of various antibacterial to 30 clinical PA:All 30 clinical strains are MDRPA.Except colistin?93.33%?,the susceptibility of 30 strains of MDRPA to all kinds of antibacterial drugs was low?all<40.00%?.?2?The enzyme production results of 30 MDRPA:A total of 18 strains contained an extended-spectrum?-lactamase gene,of which 16 strains?53.33%?contained the SHV gene,4 strains?13.33%?contained the CTX-M1 and TEM genes respectively.A total of 30 strains contained carbapenemase genes,of which 30 MDRPA contained the IMP gene,3 strains contained the KPC gene.A total of 16 strains?53.33%?contained aminoglycoside inactivating enzyme genes.All 16 strains contained aac?6'?-?gene,but did not contain ant?3''?-?gene.?3?Detection results of OprD2 gene in 30 MDRPA:OprD2 gene was deleted in only 2strains?6.67%?.?4?Sequencing results of gryA,gyrB,parC,and parE QRDR genes of 30 MDRPA:gyrA gene mutations were mainly amino acid mutations at position 83?92.86%?,and gyrB mutations were mainly 399 and 408 amino acid mutations?67.86%?.?5?Detection results of mcr-1 gene in 30 MDRPA:none of the mcr-1 gene were detected.?6?Quantitative quantitative PCR analysis of efflux pump gene expression in MDRPA:23 strains?76.67%?had at least one highly expressed efflux pump.18 strains?60.00%?performed overexpression of MexX gene.9 strains?39.13%?performed one efflux pump gene overexpression,and 14 strains?60.87%?performed two or more efflux pump genes overexpression.There was no statistical difference in the overexpression rates of the four genes in each antimicrobial-resistant group and sensitive strain group?P>0.05?.There was a certain positive correlation between the expression levels of MexC,MexE and MexX genes?Table 13,all P<0.05,r>0?,and the correlation between MexE and MexX was the largest?P<0.001,r=0.747?.3.Study on Treatment of Clinically Isolated Multidrug-resistant Pseudomonas AeruginosaMethod:?1?Formulation of combined treatment:There are 11 combined drug programs,as follows:A.Based on imipenem:combined with ciprofloxacin,ceftazidime,piperacillin,sulbactam,aztreonam,and amikacin.B.Based on Colistin:combined with ceftazidime,piperacillin and tazobactam,ciprofloxacin,amikacin,aztreonam,and imipenem.A total of 11 combined programs.?2?Statistical analysis:Descriptive analysis adoption rate,composition ratio,etc.Comparative analysis uses chi-square test.Result:?1?Imipenem-based combined susceptibility test results:The MIC values of most drugs decreased after combined use.The decline rate of imipenem combined with ciprofloxacin and imipenem combined with aztreonam was 100.00%.The drug combination of each group showed synergistic and additive effects.The synergy rate of imipenem and aztreonam reached 85.71%,and the synergy rate of imipenem and ciprofloxacin reached 68.00%.There was no statistical difference in the synergy rate between the two programs?P=0.188?,but the synergy rate between the combined drug programs was significantly higher than the other three?P<0.05?.?2?Colistin-based combined susceptibility test results:The MIC values of most drugs decreased after combined use.The decrease rate of colistin and ceftazidime was 100%,and 78.26%of the strains were sensitive to MIC of ceftazidime.The drug combination of each group showed synergistic and additive effects.The synergistic rate of colistin combined with ceftazidime reached 52.17%,which was significantly higher than the four combined regimens except colistin and amikacin.The other combined regimens generally showed synergistic or additive effects,with a small amount of irrelevant and antagonistic effects.Conclusions:1.The high rate of antibacterial use,high combined use rate and irregular selection of antibacterial and long treatment periods for surgical prevention in our hospital have largely caused high rates of multidrug resistance in survey hospitals,especially Pseudomonas aeruginosa.2.The resistance mechanism of multidrug-resistant Pseudomonas aeruginosa in our hospital is the result of the combined effect of overexpression of efflux pumps,mutations in gyrA and gyrB genes,and?-lactamase and aminoglycoside inactivating enzymes.3.Imipenem combined with ciprofloxacin,imipenem combined with aztreonam,and colistin with ceftazidime are the most effective combination regimens for multidrug-resistant Pseudomonas aeruginosa. |
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