| ObjectiveThe distribution of pathogens,the characteristics of antimicrobial resistance and the clinical application of various antibacterial agents were researched.The relationship between antimicrobial resistance of pathogens and the sum of antimicrobial agents were discussed.This research were conducted to develop a catalogue of antimicrobial management according to the regional characteristics,and optimize the selection and evaluation mechanism of antimicrobial agents.These results provide reference for promoting the rational application of antimicrobial drugs and effectively reducing bacterial resistance.MethodsA retrospective study was conducted on data of microbial culture of hospitalized patients from January 2014 to December 2017.The trends of pathogen distribution and Antimicrobial resistance rate were statistically analyzed.The data of antimicrobials applications among inpatients during the same period were extracted,and then the trend of antimicrobial use density(AUD)was calculated and analyzed.The correlation between the resistance of pathogens and the amount of antibiotics was analyzed by the pearson correlation coefficient method in SPSS 17.0 software.Results1.Distribution of pathogens and antimicrobial resistance trends1.1 Source of microbial specimensA total of 5443 positive culture samples were collected(positive rate 46.51%).The number of specimens in the respiratory tract was the highest(42.02%);the proportion of male and female patients was 63.62%and 36.36%respectively;the proportion of patients older than 60 years old was the highest(54.80%);the proportion of patients with ICU was the highest(19.25%).1.2 Pathogen composition and annual trendsA total of 9140 clinical isolates were obtained.G-bacteria detection rate was the highest(accounting for 64.80%),and showing an upward trendyear by year;G+bacteria was the next(accounting for 20.51%),and showing a downward trend year by year;the total detection rate of fungus was 14.08%,and significant change trend was not found.Among the found G-bacteria,A.baumannii had the highest detection rate(9.97%)and showed an increasing trend year by year;among the found G+ bacteria,S.aureus had the highest detection rate(3.01%),showing a little fluctuating trend;among the foundfungus,C.albicans had the highest detection rate(3.57%),followed by C.tropicalis(1.99%),showed a downward trend year by year,while Aspergillus(1.26%)showed an upward trend year by year.1.3 Detection rate and trend of resistant pathogensThe detection rate of MDR G-bacteria wasas follows:MDR-AB 52.80%,MDR-ECO 51.26%,MDR-PA 35.25%,and MDR-KP 33.79%,which showed an consecutive increased trend in three years,and had a sharp downward trend in 2017;The overall detection rates of MRSA and MRCNS were 24.36%and 78.13%respectively,and there was no obvious rule for change.1.4 Resistance rate and annual change trend of main pathogens to commonly applied antimicrobial drugs1.4.1 Resistance rate and trend of main G-bacteria to common antimicrobial agentsThe resistance rate of A.baumannii to meropenem and imipenem was more than 60%,and it was increasing year by year;the sensitivity rate to tigecycline was decreasing from 91.89%to 87.70%.K.pneumoniae was 100%sensitive to tigecycline;the sensitivity to carbapenems and amikacin was almost 90%;but the sensitivity to fluoroquinolone antibiotics was 60%to 70%.E.coli was 100%sensitive to tigecycline;and the sensitivity to ?-lactam/enzyme inhibitors,carbapenems and amikacin was almost 90%;but to fluoroquinolone such as ciprofloxacin and levofloxacin,the resistance rate of was basically above 60%,and the resistance rate was increasing year by year.The sensitivity rate of P.aeruginosa to amikacin was basically above 85%;the resistance rate to meropenem was higher and fluctuated,and the resistance rate to imipenem increased from 13.11%to 35.79.%.1.4.2 Resistance rate and trend of main G bacteria to common antimicrobial agentsThe resistance rate of S.aureus to penicillin G was over 85%.MRSA was completely resistant to penicillin G;the resistance rate to rifampicin was between 26.92%and 45.45%,and the resistance rate was decreasing year by year;the resistance rate to trimethoprim-sulfamethoxazole was almost within 10%.There were no resistant strains of vancomycin linezolid and tigecycline.The resistance rate of CoNS to penicillin G and erythromycin was more than 70%;the resistance rate to trimethoprim-sulfamethoxazole and levofloxacin was less than 30%,and it showed a downward trend year by year.MRCNS was eompletely resistant to penicillin G;the resistance rate to rifampicin was less than 20%.There were no resistant strains of vancomycin,linezolid and tigecycline.E.faecium had no resistant strains to vancomycin,linezolid and tigecycline.However,S.epidermidis had mediation of resistant to vancomycin,and a small number of E.faecalis which resistant to linezolid have appeared in the past two years.1.4.3 Resistance rate and trend of major fungus to common antifungal agentsThe resistance rate of C.albicans to itraconazole and voriconazole increased year by year.The resistance rate to itraconazole increased from 6.45 percent to 18.18 percent,while resistancerate to voriconazole increased from 3.23 percent to 12.12 percent.The sensitivity rate to amphotericin B remained above 90%.C.tropicaliswas only about 20%to 60%sensitive to itraconazole;the resistance rate to fluconazole and voriconazole was about 10%;the sensitivity to amphotericm B was almost over 90%.2.Annual AUD trends of antimicrobial agentsThe overall antimicrobial agents AUD was risen to 58.49 DDDs/(100·d)from 2014 to 2017,then dropped to 54.89 DDDs/(100·d)in 2017.The AUD of ceftazidime/tazobactamwas the highest,but it was decreasing year by year.Among cephalosporins,ceftriaxone has the highest AUD.Among the fluoroquinolones,levofloxacin has the highest AUD,but the AUD was decreasing year by year.Among the carbapenems,the AUD of meropenem was the highest,and it was increasing year by year.The amount of tigecycline was not large,but the AUD was increasing year by year.The AUD of glycopeptides showed a downward trend year by year.The AUD oflinezolid showed a continuous upward trend.Among the antifungal drugs,fluconazole had the highest application amount,and the AUD increased firstly and then decreased;amphotericin B,voriconazole and caspofungin showed a slight upward trend in each year.3.Correlation between the resistance rate of pathogens and the amount of antibiotics3.1 Correlation between the detection rate of MDR pathogens and the amount of common antimicrobial agentsThe detection rates of MDR-AB,MDR-ECO and MDR-PA were positive-correlated with the overall AUD,the AUD of ?-lactamase/enzyme inhibitor and levofloxacin(r=0.503?0.964,P>0.05).The detection rate of MDR-PA was highly positive-correlated with the overall AUD(r=0.964,P<0.05).The detection rate of MRSA was positive-correlated with AUD of penicillin,common cephalosporins,?-lactamase/enzyme inhibitors and carbapenem(r=0.183?0.82,P>0.05),while it was negative-correlated with the AUD of glycopeptides(r=-0.149?-0.445,P>0.05).3.2 Correlation between the resistance rate of major G-bacteria and the amount of common antimicrobial agentsThe resistance rate of A.baumannii to ceftazidime was highly positive-correlated with ceftazidime and the AUD of meropenem(r=0.971?0.977,P<0.05);the resistance rate to meropenem was highly positive-correlated with its AUD(r=0.986,P<0.05);the resistance rate to imipenem was highly positive-correlated with the AUD ofcephalexatin and meropenem(r=0.99?0.995,P<0.05);the resistance rate to cefoperazone/sulbactam was moderately positive-correlated with the AUD ofcephalosporin/tazobactam,cefoperazone/sulbactam and meropenem(r=0.436?0.685,P>0.05).The resistance rate of K.pneumoniae to piperacillin/tazobactam was moderately positive-correlated with the AUD of cephalosporin,cefoperazone/sulbactam and meropenem(r=0.441?0.666,P>0.05);the resistance rate to imipenem and meropenem was moderately or highly negative-correlated with their AUD respectively(r=-0.627?-0.996,P>0.05).The resistance rate of E.coli to ceftriaxone was highly positive-correlated with the AUD of P-lactamase/enzyme inhibitors such as cefoperazone/sulbactam(r=0.842?0.868,P>0.05),and moderately positive-correlated with the AUD ofceftriaxone(r=0.421,P>0.05).The resistance rate to levofloxacin was positive-correlated with the AUD of moxifloxacin and levofloxacin(r=0.408?0.535,P>0.05).The resistance rate of P.aeruginosa to cefoperazone/sulbactam was highly positive-correlated with AUD of cefoperazone/sulbactam and other ?-lactam/enzyme inhibitors(r=0.813?0.992,P>0.05).The resistance rate to imipenem and meropenem was moderately or highly positive-correlated with AUD of meropenem(r=0.683?0.919,P>0.05).3.3 Correlation between the resistance rate of major G+bacteria and the consumption of common antimicrobial agentsThe resistance rate of S.aureus to penicillin was moderately positive-correlated with AUD of penicillin(r=0.662,P>0.05),and highly negative-correlated with the AUD of gentamicin(r=-0.955,P<0.05).The resistance rate of S.epidermidis to penicillin was highly positive-correlated with the AUD of erythromycin and gentamicin(r=0.842?0.846,P>0.05);the resistance rate to erythromycin was highly positive-correlated with the AUD of gentamicin(r=0.852,P>0.05);the resistance rate to levofloxacin was highly negative-correlated with the AUD ofceftazidime/tazobactam,cefoperazone/sulbactam(r=-0.975?-0.992,P<0.05).3.4 Correlation between fungal detection rate and the consumption of common antimicrobial agentsThe detection rate of fungus was positive-correlated with total AUD,AUD of?-lactam/enzyme inhibitor,cefepime,imipenem/cilastatin and levofloxacin(r=0.41?0.8,P>0.05).3.5 Correlation between the resistance rate of fungal and the consumption of antifungal agentsThe resistance rates of C albicans and C.tropicalis to azoles were negative-correlated with the AUD of amphotericin B(r=-0.331?-0.92,P>0.05);while the resistance rates to amphotericin B was negative-correlated with the azole AUD(r=-0.264?-0.918,P>0.05);the resistance rates to voriconazole was negative-correlated with the its AUD(r=-0.515?-0.825,P>0.05).Conclusion1.There are certain tropical regiona characteristics in the distribution and resistance of pathogens in our hospital.Among the G-bacteria,the detection rate of A.baumannii is the highest,higher than the national level,and it is increasing year by year.A.baumannii have beenhighly resistant to most antimicrobial agents including carbapenems.Theresistance rate of K.pneumoniae to carbapenems is significantly lower than the national level.Although the detection rate of E.coli is decreasing,the resistance rate to fluoroquinolones ishigher than the national level with a upward trend.G bacteria are still dominated by Staphylococcus and Enterococcus,and they are highly resistant to penicillin and erythromycin.Among the G bacteria,S.epidermidis has developed vancomycin-mediated resistant strains,and a small number of E.faecalis mediates or is resistant to linezolid.Among the fungus,the detection rate of C.tropicalis is higher than that reported by other hospitals in China.The resistance rate of C albicans and C.tropicalis to azole antifungal drugs has been increasing year by year.In a word,the resistance situation of pathogens in our hospital has been extremely severe.2.The total application of antimicrobial agents has differences with the applicationin the whole country.The ?-lactams/enzyme inhibitors,fluoroquinolones and carbapenems are dominant,and the composition ratio of DDDs is significantly higher than the national level.The composition of the antifungal drug DDDs is also higher than the national level.These antimicrobial agents may be overused.3.Studies have shown that the detection rate of MDR bacteria is positive-correlated with the overall AUD.The main pathogen resistance rate is positive-correlated with the AUD of ?-lactams/enzyme inhibitors,fluoroquinolones and carbapenems which have large consumption.The fungal detection rate is positive-correlated with the AUD of broad-spectrum antibiotics;the resistance rate of Candida spp to azole antifungal is a positive correlation with the AUD of azoles.It indicates that with the increase of consumption of antimicrobial agent,the resistance rate of pathogen resistance can also increase.4.Based on the unique geographical characteristics of our hospital,it is very significant to monitor the pathogens resistance and the application of antibiotics,and to study the correlation between the resistance of pathogens and the amount of antibiotics.According to the resxults of this study,more attention to G-bacteria resistance should be paid,and the regulation of ?-lactam/enzyme inhibitors,fluoroquinolones,carbapenems and antifungal agents should be strengthended.Further monitoring of pathogens resistance should be earried on,wehile the research on the mechanism of pathogens resistance should be strengthened.It will promote rational use of antimicrobial agents and slow down the process of bacterial resistance. |
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