Characterization And Antimicrobial Resistance Of Diarrheagenic Esch Erichia Coli From Acute Diarrhea Patients In Hangzhou Area From2011to2013

Background/Aims:To study the epidemiological characteristics and antibacterial resistance of diarrheagenic Escherichia coli.(DEC) isolated from acute diarrhea patients from Hangzhou area in Zhejiang Province during July2011to June2013. So as to provide evidence for epidemiological study, vaccine preparation and rational use of antibiotics in DEC clinical practice.Methods:The suspicious strains was isolated, cultured, detected and confirmed from acute diarrhea patients in Hangzhou area by regular microbial methods and the DEC classes was identified by biochemistry identification and multiplex PCR techniques. O/H serotype of DEC was detected by direct agglutination test respectively. Disk diffusion (K-B methods) was carried out to detect strains sensitivity to19antibiotics and strains producing ESBL. The experimental results were analyzed using the information survey results of cases, mainly about the epidemic characteristics and drug resistances tendency of DEC in Hangzhou area.Results:(1) A total of1246fecal specimens were collected from3sentinel hospitals from July2011to June2013in Hangzhou area, among which263strains of diarrheagenic Escherichia coli. were isolated. The detection rate was21.1%, including55.9%of EAEC,34.6%ETEC and9.5%EPEC. There was no detection of STEC and EIEC. The detection rate was higher in summer and autumn.(2) Among263isolates, explicit serogroups accounted for164(62.4%), belongs to28kinds of serotype O,17H serotypes and unknown serum groups. The top three0and H serotype types are0159(9.5%),0148(6.5%),06(5.3%) and H34(7.2%), HI8(5.3%), H16(4.2%) respectively. The agglutination rate of EAEC, EPEC and ETEC were54.4%,72.7%and64%.(3) The drug resistant results were as follows:51.3%,43%and35.4%of DEC strains were resistant to AMP, Compound Sulfamethoxazole and Cefazolin, less than10%of the strains were resistant to Cefoxitin, Nitrofurantoin, Amikacin, Ceftazidime, Cefepime, Imipenem and Tazocin piperacillin. There was a significant difference of drug resistance rate among EAEC, ETEC and EPEC. EAEC has the highest rates of drug resistance, while ETEC group has the lowest resistance rate.(4) There were82strains which produced ESBL in the whole263DEC strains and the positive rate was32.2%(82/263). The EAEC, ETEC and EPEC producing rate in the positive strains was35.4%,19.8%and48%respectively.(5) There were116strains of multiple antibiotic resistance strains (44.1%), among which there were85strains of EAEC,20strains of EPEC, and11strains of ETEC. The multiple antibiotic resistance rate was82.9%in the82ESBL producing strains. Conclusions:In recent two years, the detection rate of diarrheagenic Escherichia coli was increased in Hangzhou area. The positive cases were mainly infection of EAEC, ETEC and EPEC, which has a higher drug resistance rate of several antimicrobial agents. Some multiple antibiotic resistance bacteria have appeared. Thus, surveillence and drug sensitivity test should be performed in order to guide the clinical rational use of antibiotics. The relevant departments should pay serious attention to the acute diarrhea caused by diarrheagenic Escherichia coli, monitor carefully and prevent cautiously to avoid the outbreak.