| Objective:Escherrchia coli is one of the main pathogenic bacteria in hospital infection and its separation rate is higher in the process of laboratory testing.Based on the analysis of the clinical manifestations,the types of infection and the diversity of infection sites are presented.The drug sensitivity of Escherrchia coli directly affects the duration and prognosis of patients.Therefore,the study on the mechanism of drug resistance of Escherichia coli has gradually become a hot topic in the prevention and treatment of nosocomial infections.However,the mechanism of drug resistance of Escherichia coli isolated from nosocomial infection has not yet been determined,and the production of β-lactamase is one of the most important mechanisms of Escherichia coli resistance to beta lactam antibiotics.Therefore,this study was conducted to analyze the clinical detection rate and drug resistance of Escherichia coli in Nangong hospital,to provide scientific basis for rational use of antibiotics and early prevention and control of nosocomial infection.Methods:1 Collection of strains :Clinical specimens were collected from the laboratory of Microbiology in Nangong city from January 2016-October 2016,and 98 strains of Escherichia coli were isolated.The bacteria were identified by XIN-KE microbial identification instrument,the strain was identified and then transferred to the EP tube containing nutrient broth and incubated for16-20 hours after being placed in the refrigerator at-20℃ for preservation.2 Detection of β-lactamase producing Escherrchia coli: Each bacterrial strain was detected using rapid detection test method which can detect β-lactamase.3 Screening of producing beta lactamase positive samples,collected and positive in patients with clinical data,analysis of beta lactamase producingEscherichia coli samples,as well as its clinical distribution caused by infectious diseases.4 Analysis of drug resistance of producing β-lactamase Escherrchia coli.4.1 Broth microdilution method was used to detect MIC values of 5 kinds of antibiotics for analyzing their drug resistance.4.2 Determination of the production of beta lactamase K-B of Escherichia coli to 12 commonly used antibiotics in clinical drug resistance,using the chi-square test,analysis of bacterial resistance to various antibiotics was no significant difference compared with that of standard strain,the test level is a=0.05.Results:1 January 2016-October 2016 in Nangong City People’s Hospital collected242 infections specimens,detection results of Escherichia coli strains were98,and the positive rate was 40%.2 The strains of producing beta lactamase were 82 detected in 98 strains of Escherichia coli,the positive rate was up to 84%(see table 3).3 The sources of producing β-lactamase Escherrchia coli strains specimens were given priority to with the wound secretion,followed by urine and sputum.The detection rate from high to low in turn as follows: the wound secretion 30.5%(25/82),urine 26.8%(22/82),sputum 21.9%(18/82),blood7.3%(6/82),feces 6.1%(5/82),puncture fluid 3.7%(3/82),drainage of liquid 3.7%(3/82)(see table 4).4 The detection rate of producing β-lactamase Escherrchia coli from high to low in turn department as follows: general-surgery30.5%,urology22%,respiratory medicinel 4.6%,ICU 12.2%,department of gastroenterology 7.3%,department of cardiology 4.9%,neurosurgery 3.7%,department of pediatrics2.4%(see figure 1).Mainly is caused by trauma surgery infection(37.8%)and urinary tract infection(26.8%)(see figure 2).5Producing β-lactamase Escherrchia coli were highly resistant to many antibiotics.5.1 Results of broth microdilution method show that the MIC of 5 kinds ofantibiotics as follows: cotrimoxazole 0.125ug/ml,drug resistance rate 80.5%;ceftazidime 0.5ug/ml,drug resistance rate 61%;ampicillin sulbactam 0.25ug/ml,drug resistance rate 48.8%;macrodantin 2ug/ml,drug resistance rate14.6%;amikacin 0.5ug/ml,drug resistance rate 4.9%(see table 6).5.2 Results of K-B method showed that escherichia coli were highly resistant to multiple antibiotics,but sensitive to imipenem.The drug ressitance rates were ranked from high to low as follows: ampicillin85.4%、levolloxacin68.3%,gentamicin63.4%,ciprofloxacin62.2%,cefotaxime52.4%,ceftazidime45%,cefepime42.7%,aztreonam30.5%,piperacillin/tazobactam13.4%,amikacin9.8%,cefoperazone/sulbactam4%(see table 10).There was no significant difference between the drug resistance rate of gentamicin and the drug resistance rate of levolloxacin(P>0.05),there was no significant difference between the drug resistance rate of gentamicin andthe drug resistance rate of ciprofloxacin(P>0.05),there was no significant difference between the drug resistance rate of ceftazidime and the drug resistance rate of cefepime(P>0.05),and there was a significant difference between other antibiotics(P<0.05)(see table 11).6 Results of multiple drug resistance: dual drug resistance accounted 34.1%;triple drug resistance 48.8%;quadruple drug resistance 8.5%.Conclusions:1 Escherichia coli was the main opporrunistic pathogen in hospital infection,it could cause multiple organ infection.Various clinical departments and all kinds of type specimens were detected,distribution of department was given priority to with general surgery department,the specimen type was given priority to with the wound secretion specimens,often cause surgical infectious disease.2 β-lactamase producing escherrchia coli were lowly resistant to nitrofurantoin,amikacin,piperacillin/tazobactam,cefoperazone/sulbactam,whereas were high resistant to cotrimoxazole,ampicillin.So the hospital should strengthen the detection and monitoring of escherrchia coli resistance,completes the bacterial culture and drug sensitivity test,specification andreasonable use of antibiotics,to control the emergence of resistant bacteria and popular.3 Producing β-lactamase escherichia coli was more sensitive to carbapenem antibiotics,so carbapenem antibiotics could be used as the first choice for the treatment of infectious diseases caused by producing beta lactamase escherichia coli. |
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