| Background:Helicobacter pylori(Hp)infection is a global problem,the worldwide infection rate has exceeded 50%.Eradication of Hp can improve the ulcer healing rate and reduce the incidence of gastric cancer.The conventional therapy for Hp eradication is standard triple therapy,including two antibiotics and proton pump inhibitors(PPI).The selection of antibiotics including first-line drugs(clarithromycin,amoxicillin,metronidazole)and second-line drugs(levofloxacin).Due to the irrational use of antibiotics,the resistance rate of antibiotics increased year by year,which has become the main reason for the failure of Hp treatment.And combined with the factors of bacterial and host,the eradication rate of Hp was less than 80%.Bacterial factors include the increase of the resistance rate of Hp,the function of bacteria efflux pump,the formation of bacterial biofilm and bacterial infection in cells.Hp culture is still the gold standard method for diagnosis of Hp infection,and can carry out drug sensitivity test,bacterial genotyping and pathogenic gene research,etc.However,Hp culture technology requires high demand and long time,with certain conditions limit.At the same time,due to the lack of bacteria in gastric mucosa tissue,distribution of focus,poor reproductive ability,and bacterial translocation after treatment may affect the cultivation of Hp,Which leads to false negative results of culture;In addition,for children with peptic ulcer and pepticulcer bleeding,we must use the experience medication before the Hp culture and drug sensitivity results.Therefore,how to diagnose Hp infection quickly and accurately,and choose therapeutic regimen according to the drug resistance result are the keys to start early and effective treatment of Hp infection.Gene chip technology is a rapidly developed molecular biology technology in recent years,which principle is to focus the analysis process of life science on the construction of micro analysis system to achieve accurate,fast,high-throughput and multi-channel detection of protein,nucleic acid and so on.In this study,we detected helicobacter pylori infection in children and its drug resistance by gene chip technology of gastric mucosa,and compared with the results of Hp culture and drug sensitivity,evaluate the clinical value of gene chip technology in diagnosis and drug resistance detection of helicobacter pylori infection in children.Purpose:Detection of helicobacter pylori(Hp)infection in children and its drug resistance by gastric mucosa gene chip technology,and compare with the results of Hp culture and drug sensitivity,evaluate the clinical value of gastric mucosa gene chip technology in diagnosis of helicobacter pylori infection in children and detection of drug resistance.Method:For children suffering from digestive system symptoms of nausea,vomiting,Hematemesis,acid reflux,hiccups,abdominal pain and melena in outpatients or hospitalized in our hospital from January 2016 to may 2016,who were examined by electronic gastroscopy,3 pieces of gastric antrum mucosa were obtained under gastroscope,which carried out separately for routine pathological examination,rapid urease test(RUT),and Hp isolation culture and drug sensitivity test,which were conducted to read the minimum inhibitory concentration(mic)and to determine the drug resistance.All the gastric mucosa rut specimens of Hp culture were collected and stored at-80?.The bacterial DNA was extracted,and Hp infection and the resistance gene were detected rapidly by gene chip technology.The results of Hp culture and drug sensitivity test were compared with the results of gene chip resistance gene examination.Results:1.According to the diagnosis basis of Hp infection,it is divided into Hp infection group(207 cases)and non Hp infection group(60 cases).Hp culture was positive in 169 cases(all were Hp infection group),negative 98 cases(38 cases in Hp infection group,60 cases in non Hp infection group),the sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV)and accuracy of Hp infection were 81.6%,100.0%,100.0%,61.2%and 85.8%.And Hp gene chip detection was positive in 208 cases(199 cases in Hp infection group,9 cases in non Hp infection group),negative 59 cases(8 cases in Hp infection group,51 cases in non Hp infection group).And its sensitivity,specificity,PPV,NPV and accuracy were 96.1%,85.0%,95.7%,86.4%and 93.6%.2.The drug sensitivity results of 169 cases of Hp culture-positive were showed that the drug resistance rates of metronidazole,clarithromycin and levofloxacin were 77.51%,33.72%,19.52%and the fully sensitive strain accounted for 11.83%.Tetracycline and amoxicillin resistant strains were not detected.The 199 cases of Hp infection group were detected by gene chip and the results showed that the drug resistance rates of metronidazole,clarithromycin,levofloxacin and amoxicillin were 44.72%,63.31%,18.09%,12.56%,and the fully sensitive strain accounted for 14.07%.Tetracycline resistant strain was not detected.3.The gene chip detected the Hp resistance gene locus,and the results showed that the main mutation locus of clarithromycin was 2143A/Q accounting for 92.9%,of which there was a double mutation.Levofloxacin mutations were 91 locus(58.3%)and 87 locus(41.7%),the main mutation locus of amoxicillin was 556ser,accounting for 84%.4.Compared with 130 cases which were positive for both Hp drug sensitivity test and drug resistance gene detection,the results showed that the coincidence rate of drug resistance to metronidazole was 76.2%,and the rate of sensitive coincidence was 19.7%,the compliance rate of drug resistance to clarithromycin was 52.2%,and the sensitivity coincidence rate was 92.8%,the compliance rate of drug resistance to levofloxacin was 58.3%,and the sensitivity coincidence rate was 89.6%.5.Compared with 22 cases which were detected by gene chip and sequencing,the results showed that the concordance rates of SM,16s-RNA,23s-RNA and gyrA were higher than 95%,and the concordance rate of PBP1 and rdxA was higher than 80%.Conclusion:1.Hp gene chip technology of gastric mucosa can quickly diagnose Hp infection,its sensitivity and accuracy are higher than Hp culture.2.Gene chip technology can quickly determine drug resistance of Hp by detecting common resistance gene locus,compared with the results of Hp culture and drug sensitivity,the sensitivity coincidence rate of tetracycline,clarithromycin,levofloxacin were about 90%,and the rate of metronidazole was lower.3.The consistency of gene chip technology and sequencing is good,and gene chip examination can well respond to the genotype of Hp resistance.4.Gene chip technology of gastric mucosa can be used for rapid diagnosis and drug resistance analysis of children with Hp infection. |
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