Study On Carriage,antimicrobial Resistance And Serotype Of Streptococcus Pneumoniae In Children In Suzhou

Objective:To investigate the carriage,antimicrobial resistance and serotype distribution of Streptococcus pneumoniae(SP)in hospitalized children in Suzhou,and to analyze the factors affecting the carriage,summarize the antimicrobial resistance mode,and evaluate the coverage rate of pneumococcal conjugate vaccine.The goal is to provide scientific basis for controlling the prevalence of SP and reducing pneumococcal resistance.Methods:(1)From January 2017 to December 2018,the clinical data of hospitalized children with SP in Suzhou University affiliated Children's Hospitalwere collected and analyzed.(2)Kirby-Bauer disk diffusion test and E-test method were used to test the drug sensitivity of 2446 SP collected from 2017 to 2018,and the clinical data of these SP carrier were collected.(3)The serotyping of SP strains collected from January 2017 to May 2018 was carried out by capsule swelling test.Results:1.The pneumococcal carriage in hospitalized childrenThe carriage rate of SP in nasopharynx was 15.2%(3341/22051).There were significant differences in SP carriage rate in nasopharynx between children admitted to hospital and children of different ages in different seasons(P<0.001).The carriage rate of SP in nasopharynx was the highest(16.7%)in autumn.The carriage rate of SP in nasopharynx was the lowest(5.3%)from 0 to 6 months old,the highest(27.2%)in children aged 3-5 years old.2.The antimicrobial resistance of SP isolated from hospitalization childrenThe insensitive rates of SP isolates to erythromycin,clindamycin,tetracycline and compound neomycin were 99.9%,98.1%,89.7%and 87.9%,respectively.The insensitive rates of the strains to penicillin,amoxicillin and cefotaxime were 9.5%,27.7%and 27.2%,respectively.The insensitive rate of the strain to levofloxacin and mosifloxacin was 0.1%.The strain was completely sensitive to vancomycin and linezolid.The insensitive rate of SP invasive isolates to penicillin G and mosifloxacin was higher than that of non-invasive isolates(48.6%vs 8.9%,p<0.001;3.6%vs 0.1%,p=0.029).The insensitive rate of penicillin insensitive SP to amoxicillin and cefotaxime was significantly higher than that of penicillin sensitive SP(82.6%vs 22.1%,p<0.001;86.2%vs 21.0%,p<0.001).Compared with ?lactam antibiotic sensitive SP,?lactam antibiotic insensitive SP had higher insensitive rate to tetracycline and compound neomycin,and the difference was statistically significant.(94%vs 87.6%,p<0.001;95%vs 84.4%,p<0.001).97.6%of SP strains showed multidrug resistance.The most common drug resistance pattern was Macrolides+compound norepinephrine+clindamycin+tetracycline(44.4%).3.The serotype of SP in hospitalized children.The top five serotypes of SP in Suzhou were 19F(28.6%),6B(11.9),23F(11.2%),6A(10.6%)and 19A(9.1%).These common serotypes are sequenced differently in different age groups.The distribution of SP serotype was different in children with different conditions:(1)In bronchopneumonia group,the first five serotypes were 19F,6B,6A,23F,19A in turn,and in lobar pneumonia group,the first five serotypes were 19F,23F,6B,NT,14 in turn.(2)In the non-severe pneumonia group,the first five serotypes were 19F,23F,6B,6A,19A,and in the severe pneumonia group,the first five serotypes were 19F,6B,6A,23 F,19A/23A.The serotype distribution of SP with different drug resistance was different:(1)Among penicillin sensitive strains,the first five common serotypes were 19F,6B,6A,23 F,19A respectively,and among penicillin insensitive strains,the first five serotypes were 19F,6B,6A,23F and 19A,respectively.(2)Among the strains sensitive to ?-lactam,the first five common serotypes were 6B,6A,23F,19F,14.Among the strains insensitive to ?-lactam,the first five common serotypes were 19F,19A,6B/23F,14,6A,respectively.(3)Among the non-multidrug resistant SP strains,the first two common serotypes were 23F/14 and 19F,and among the multidrug resistant SP strains,the first five serotypes were 19F,6B,6A,23F and 19A,respectively.The serotype coverage of 7-valent SP combined vaccine and 13-valent SP combined vaccine were 60.4%and 80.9%,respectively.Conclusions:1.The carriage rate of nasopharynx SP in hospitalized children in Suzhou area from 2017 to 2018 was 15.2%.Age and season had an effect on the carriage rate of SP in nasopharynx.The SP carriage rate of nasopharynx was the highest in children admitted to hospital in autumn.The SP carriage rate of nasopharynx was the highest in hospitalized children from 3 to 5 years old.2.There is multiple drug resistance in SP in Suzhou area,and macrolides+compound norepinephrine+clindamycin+tetracycline is the most common drug resistance mode.However,the sensitivity rate of SP to penicillin is high,which has important guiding value for the selection of clinical antibiotics.3.The main serotypes of SP in Suzhou were 19F,6B,23F,6A and 19A.The distribution of serotypes was different in different ages,different conditions and different drug resistance.The 13-valent SP combined vaccine in Suzhou area has better protective effect than the 7-valent SP combined vaccine.