Serotype,molecular Typing And Drug Resistance Of Salmonella In Diarrhea Cases In Sentinel Hospitals Of Ma′anshan From 2015 To 2019

Objective To investigate the infection status,serological distribution,molecular typing and drug resistance of Salmonella diarrhea in Ma’anshan.analysis of epidemic characteristics of salmonella in this region and the changes of the serotype distribution,establish salmonella molecular classification and drug resistance monitoring database,so as to provide a scientific basis for prevention and control of salmonella diarrhea in this region.Methods In this study,serum type,pulse field gel electrophoresis(PFGE)and drug sensitivity tests were performed on salmonella isolated from diarrhea cases in three sentinel hospitals in Ma’anshan city from 2015 to 2019.SPSS20.0 was used for statistical analysis of the data,χ~2test was used for rate comparison,P<0.05 was considered statistically significant,and Bio Numerics 7.6 software was used for cluster analysis of PFGE images.After calibration,the unweighted paired arithmetic mean method(UPGMA)was used to construct the cluster graph.Results1.The infection rate of salmonella was 15.7%(284/1809)among diarrhea patients insentinel hospital of Ma’anshan from 2015 to 2019,Salmonella infection rates werehigher insummer,The incidence was higher in the 0～5 and 35-54 age groups,respectively 18.5%(103/556)and 18.2%(66/363).2.The 288 salmonella strains were divided into 28 serotypes,mainly salmonella agona(20.1%),salmonella typhimurium(19.8%)and salmonella enteritis(15.6%),ofwhich salmonella undefined accounted for 18.1%,with different serotypes indifferent years.3.The PFGE distribution of salmonella agona was relatively concentrated,and the time interval of multiple cases was short.However,the PFGE type of salmonella typhimurium showed higher polymorphism.Although clusters of strains appeared inthe PFGE map of salmonella enteritis,the onset time of each case was far from eachother.4.The fli C gene fragments of[7:?:5]and[7:k:5]Salmonella had the highest homology(99.74%～100%)with LS483493.1 and CP041171.1(Salmonella Thompson).The amino acid homology of all sequences was 100%.PFGE typing showed that 66.7%[7:k:5]salmonella had a molecular weight of about 1135kb,2.8%[7:?:5]salmonella had the band(χ~2=17.774,P<0.001).5.The drug resistance rates of the tested strains to AMP and STR were 37.4%and36.5%respectively,while they were all sensitive to AZI and IMI.There were no statistically significant differences in the total drug resistance rate,multiple drug resistance rate and drug resistance to 27 antibiotics of the strains from age 5 below and above.6.Compared to salmonella typhimurium,salmonella enteritis is more sensitive to tetracycline(TET,MIN,DOX)and CHL,but less sensitive to polymyxin(CT,PB),AMP,NAL,CFZ and Sul,all of which are statistically significant.Conclusions1.The infection rate of salmonella in diarrhea patients in ma’anshan from 2015 to2019 was 15.7%,and the dominant serotype was salmonella agona.2.The salmonella[7:?:5]that is prevalent in this area is salmonella Thompson.3.The total drug resistance rate of salmonella isolated in 2019 was 44.8%,themultiple drug resistance rate was 36.5%,the drug resistance rate to AMP and STR was higher,and all were sensitive to AZI and IMI.Salmonella typhimurium and salmonella enteritis have different susceptibility to different antibiotics.