Objective:To investigate the clinical characteristics of non-typhoidal Salmonella（NTS）enteritis in children and the drug resistance of NTS strains.Methods:The clinical data of 138 children who were hospitalized in Children's Hospital Affiliated to Xi'an Jiaotong University from 2022 to 2023 with diarrhea as the main complaint and NTS detected in stool culture were analyzed retrospectively, and the clinical characteristics and drug resistance were summarized.Results:Among 138 children with NTS enteritis，89 were males and 49 were females，with a male-to-female sex ratio of 1.81∶1 and an average age of 1.9（1.0,3.6）years，with a high incidence rate in June,July and August.Seventeen（12.31%）cases had a history of suspected unclean diet before illness.All the children had diarrhea symptoms with changes in fecal frequency and character，including 74 cases of pus and bloody stool，119 cases of mucus stool，and 70 cases of watery stool.One hundred and twenty-five（90.57%）cases had fever.Among 138 cases of fecal culture,there were 47 (34.05%) strains of Salmonella typhimurium,36(26.09%) strains of Salmonella enteritidis,and 55(39.85%) strains of other serotypes of Salmonella .One hundred and twenty-two（88.40%）NTS strains were resistant to more than one antimicrobial agent，and 29（21.01 %）were multi-drug resistant.The resistance rates to ampicillin，ampicillin/sulbactam，ceftriaxone，trimethoprim/sulfamethazole，ceftazidime，cefepime and piperacillin/tazobactam were 73.91%，71.01%，29.71%，29.71%，23.19%，11.59%，and 3.62%，respectively.All strains were sensitive to carbapenem antibiotics（meropenem，imipenem，and ertapenem）.The drug resistance rates of Salmonella typhimurium to ceftazidime and trimethoprim/sulfamethoxazole were higher than those of Salmonella enteritidis（38.30% vs 8.33%），the difference was statistically significant ( P < 0.05). Conclusion:Infants and young children are the high-incidence group of NTS enteritis，with the peak incidence period being from June to August each year，manifested by mucus-pus-blood stools, abdominal pain, vomiting，fever and other symptoms.Reasonable selection of antibiotics in time according to the local epidemic strains,changes of antimicrobial resistance and the results of drug sensitivity test of strains can effectively resist infection and reduce the production of drug-resistant beads.

Objective:To investigate the clinical characteristics of non-typhoidal Salmonella（NTS）enteritis in children and the drug resistance of NTS strains.Methods:The clinical data of 138 children who were hospitalized in Children's Hospital Affiliated to Xi'an Jiaotong University from 2022 to 2023 with diarrhea as the main complaint and NTS detected in stool culture were analyzed retrospectively, and the clinical characteristics and drug resistance were summarized.Results:Among 138 children with NTS enteritis，89 were males and 49 were females，with a male-to-female sex ratio of 1.81∶1 and an average age of 1.9（1.0,3.6）years，with a high incidence rate in June,July and August.Seventeen（12.31%）cases had a history of suspected unclean diet before illness.All the children had diarrhea symptoms with changes in fecal frequency and character，including 74 cases of pus and bloody stool，119 cases of mucus stool，and 70 cases of watery stool.One hundred and twenty-five（90.57%）cases had fever.Among 138 cases of fecal culture,there were 47 (34.05%) strains of Salmonella typhimurium,36(26.09%) strains of Salmonella enteritidis,and 55(39.85%) strains of other serotypes of Salmonella .One hundred and twenty-two（88.40%）NTS strains were resistant to more than one antimicrobial agent，and 29（21.01 %）were multi-drug resistant.The resistance rates to ampicillin，ampicillin/sulbactam，ceftriaxone，trimethoprim/sulfamethazole，ceftazidime，cefepime and piperacillin/tazobactam were 73.91%，71.01%，29.71%，29.71%，23.19%，11.59%，and 3.62%，respectively.All strains were sensitive to carbapenem antibiotics（meropenem，imipenem，and ertapenem）.The drug resistance rates of Salmonella typhimurium to ceftazidime and trimethoprim/sulfamethoxazole were higher than those of Salmonella enteritidis（38.30% vs 8.33%），the difference was statistically significant ( P < 0.05). Conclusion:Infants and young children are the high-incidence group of NTS enteritis，with the peak incidence period being from June to August each year，manifested by mucus-pus-blood stools, abdominal pain, vomiting，fever and other symptoms.Reasonable selection of antibiotics in time according to the local epidemic strains,changes of antimicrobial resistance and the results of drug sensitivity test of strains can effectively resist infection and reduce the production of drug-resistant beads.

Objective:To study the distribution of drug resistance genes and virulence genes in multidrug-resistant Salmonella typhimurium strains.Methods:A total of 96 strains of Salmonella typhimurium were collected，and drug sensitivity tests were performed to evaluate the drug resistance and multidrug-resistance of Salmonella typhimurium.Multidrug-resistant Salmonella typhimurium strains were selected to conducted whole genome sequencing，and the distribution of drug resistance genes and virulence genes in the strain were analyzed.Results:Salmonella typhimurium strains had the highest resistance rates to ampicillin and ampicillin/sulbactam，with 89.58% and 76.04%，respectively.Followed by trimethoprim/sulfamethoxazole，ceftriaxone，and aztreonam，with 47.92%，38.54% and 33.33%，respectively，and low resistance rates to ciprofloxacin and levofloxacin，with 8.33% and 4.17%，respectively.Ninety-six strains were all sensitive to carbapenem antibiotics and piperacillin/tazobactam.Fifty-seven strains（59.38%）of Salmonella typhimurium showed multidrug-resistance.Resistance genes were detected in all 57 multidrug-resistant Salmonella typhimurium strains,with higher carrier rates of 98.25%,77.19%,and 59.65% for aac(6')-Iaa,aadA22,and blaTEM-1B,respectively.The multidrug-resistant Salmonella typhimurium strains had the highest carrier rates for invA，sipA，sseL，and sopB.Conclusion:Multidrug-resistant Salmonella typhimurium strains have a high incidence and a high carrier rate for multiple drug resistance genes and virulence genes.The monitoring and prevention of Salmonella typhimurium should be strengthened in the clinic in order to reduce the spreading epidemic of multidrug-resistant strains.