Objective:To study the clinical and microbiological characteristics of invasive Salmonella infection in children. Methods:Clinical data of children with invasive Salmonella infection diagnosed in the Children′s Hospital Zhejiang University School of Medicine and Women and Children′s Hospital of Ningbo University from January 2018 to June 2022 were retrospectively analyzed, and the serotypes and drug resistance of the pathogens were detected. The chi-square test was used to compare the resistance rates of different Salmonella serogroups to antibiotics. Results:A total of 105 invasive Salmonella infection cases were included, with ages of 20.0 (12.3, 43.5) months, and 67 cases(63.8%)were male. Fifty-seven cases occurred in summer (from June to August). Eighty-seven cases were confirmed by blood culture, 10 cases by bone marrow or bone marrow cavity pus culture, six cases by cerebrospinal fluid and other specimen culture, with an additional two cases where Salmonella was cultured from two types of specimens including blood, bone marrow or cerebrospinal fluid. Thirty-six patients had underlying diseases, of which 58.3%(21/36) were leukemia. The resistance rates of the strains to ampicillin, ceftriaxone, ceftazidime, piperacillin-tazobactam, imipenem, and trimethoprim-sulfamethoxazole were 48.5%(51/105), 12.3%(13/105), 9.5%(10/105), 1.9%(2/105), 0(0/105), and 29.5%(31/105), respectively. Ninety-nine strains (94.3%) belonged to invasive non-typhoidal Salmonella (iNTS), four strains were Salmonella typhi, and 13 strains were Salmonella typhimurium. The resistance rate of group D strains to ceftriaxone was lower than that of group B ( χ2=5.38, P=0.020) and group E ( χ2=5.74, P=0.017). The resistance rate of group D strains to trimethoprim-sulfamethoxazole was lower than that of group C ( χ2=5.67, P=0.017), group B ( χ2=13.02, P<0.001) and group E ( χ2=9.00, P=0.003), and the differences were all statistically significant. The symptoms of fever and diarrhea accounted for 94.3%(99/105) and 51.4%(54/105), respectively. The most common diagnosis was septicemia, accounting for 88.6%(93/105), pyogenic osteomyelitis with pyogenic arthritis accounted for 10.5%(11/105), and four patients (3.8%) developed purulent meningitis. All 105 patients received antibiotic treatment, 101 patients (96.2%) were cured or improved, and four cases (3.8%) died. Conclusions:iNTS infection is more common than typhoid fever in children. Different serotypes of strains have different resistance to antimicrobial drugs. Invasive strains such as bloodstream are more sensitive to the third-generation cephalosporin. The third-generation cephalosporin is still the first choice for the treatment of iNTS diseases.

Objective:To study the clinical and microbiological characteristics of invasive Salmonella infection in children. Methods:Clinical data of children with invasive Salmonella infection diagnosed in the Children′s Hospital Zhejiang University School of Medicine and Women and Children′s Hospital of Ningbo University from January 2018 to June 2022 were retrospectively analyzed, and the serotypes and drug resistance of the pathogens were detected. The chi-square test was used to compare the resistance rates of different Salmonella serogroups to antibiotics. Results:A total of 105 invasive Salmonella infection cases were included, with ages of 20.0 (12.3, 43.5) months, and 67 cases(63.8%)were male. Fifty-seven cases occurred in summer (from June to August). Eighty-seven cases were confirmed by blood culture, 10 cases by bone marrow or bone marrow cavity pus culture, six cases by cerebrospinal fluid and other specimen culture, with an additional two cases where Salmonella was cultured from two types of specimens including blood, bone marrow or cerebrospinal fluid. Thirty-six patients had underlying diseases, of which 58.3%(21/36) were leukemia. The resistance rates of the strains to ampicillin, ceftriaxone, ceftazidime, piperacillin-tazobactam, imipenem, and trimethoprim-sulfamethoxazole were 48.5%(51/105), 12.3%(13/105), 9.5%(10/105), 1.9%(2/105), 0(0/105), and 29.5%(31/105), respectively. Ninety-nine strains (94.3%) belonged to invasive non-typhoidal Salmonella (iNTS), four strains were Salmonella typhi, and 13 strains were Salmonella typhimurium. The resistance rate of group D strains to ceftriaxone was lower than that of group B ( χ2=5.38, P=0.020) and group E ( χ2=5.74, P=0.017). The resistance rate of group D strains to trimethoprim-sulfamethoxazole was lower than that of group C ( χ2=5.67, P=0.017), group B ( χ2=13.02, P<0.001) and group E ( χ2=9.00, P=0.003), and the differences were all statistically significant. The symptoms of fever and diarrhea accounted for 94.3%(99/105) and 51.4%(54/105), respectively. The most common diagnosis was septicemia, accounting for 88.6%(93/105), pyogenic osteomyelitis with pyogenic arthritis accounted for 10.5%(11/105), and four patients (3.8%) developed purulent meningitis. All 105 patients received antibiotic treatment, 101 patients (96.2%) were cured or improved, and four cases (3.8%) died. Conclusions:iNTS infection is more common than typhoid fever in children. Different serotypes of strains have different resistance to antimicrobial drugs. Invasive strains such as bloodstream are more sensitive to the third-generation cephalosporin. The third-generation cephalosporin is still the first choice for the treatment of iNTS diseases.

Objective To analyze the clinical features,etiology and antibiotics-resistance in purulent meningitis cases identified in our hospital during the recent 5 years.Methods Clinical data were collected and the etiology and antibiotics-resistance were analyzed in 36 children with purulent meningitis during Jan 2007 to Oct 2011,and all cases were identified by a positive cerebrospinal fluid culture.Results There were 2 267 cerebrospinal fluid samples cultured and only 36 samples showed positive results and the rate was 1.6％,and 27 strains (75.0％,27/36) were Gram positive cocco bacteria.The most common bacterium was coagulase negative Staphylococcus and the ratio was 50.0％ (18/36),followed by Escherichia coli ( 13.9％,5/36),Streptococcus pneumonia ( 11.1％,4/36) and Staphylococcus aureus ( 8.3％,3/36).Drug sensitive test showed that 95.2％ of the Staphylococcus was β-lactamase positive and resistant to penicillin,and 33.3％ were sensitive to oxacillin.The death rate was 13.9％ (5/36).Conclusion Staphylococcus,Escherichia coli and Streptococcus pneumonia are the top three pathogens causing purulent meningitis in children in our hospital,and clinicians should choose antibiotics according to the result of drug sensitive test.