Objective:To investigate the correlation of the emm genotypes and virulence genes with the isolation sites of Group A Streptococcus (GAS). Methods:It was a retrospective study.The specimens were collected from children with impetigo in Beijing Children′s Hospital, Capital Medical University from 2006 to 2008 for GAS isolation and identification.A total of 24 GAS strains were isolated from 16 children with impetigo, among which 7 pairs of strains were isolated from the throat and skin of 7 children, and 1 pair of strains was isolated from the vulva and skin of one child, and the remaining 8 GAS strains were isolated from the skin pus samples of 8 children.Polymerase chain reaction was applied to detect the emm genotypes and 13 virulence genes ( speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa). The correlation of the emm genotypes and virulence genes with the isolation sites of GAS strains was analyzed. Results:In this study, four emm genotypes were detected, including emm1.0 (15/24), emm12.0 (4/24), emm22.0 (2/24) and emm160.0 (1/24), and one subtype emm12.19 (2/24) was detected as well.The carrying rates of 13 virulence genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were 58.3%, 100%, 91.7%, 100%, 50.0%, 12.5%, 54.2%, 66.7%, 16.7%, 25.0%, 12.5%, 100% and 91.7%, respectively.All strains carried 5 to 11 virulence genes and they all carried speB, speF and smeZ.There were significant differences in the carrying rate of speA and speJ among the strains with different emm genotypes (all P<0.05). There was no significant difference in the distribution of virulence genes between skin isolates and pharyngeal isolates, including the 5 pairs of strains carrying the emm1.0 genotype (all P>0.05). Conclusions:The distribution of virulence gene of GAS in children with impetigo is significantly correlated with the emm genotype, rather than the isolation site.

Objective:To investigate the correlation between pulmonary ultrasound on pulmonary consolidation and T lymphocytes,cytokines in predicting the progression of neonatal pneumonia.Methods:A total of 80 pediatric patients with pulmonary consolidation,who admitted to neonatal ward of Beijing Chao-yang Hospital and were confirmed by the first ultrasound examination on lung from February 2021 to February 2023,were divided into study group,and 50 children,who underwent physical examination during the same period,were divided into control group.The cell subsets and cytokines between two groups were compared.The study group was further divided into mitigation group and progression group according to the disease conditions of pediatric patients of study group after they received 3 d treatment.Multifactor logistic regression was adopted to analyze the correlation among the T lymphocytes,cytokines and the progression of disease.Results:The CD3+,CD8+,CD4+/CD8+cell subsets of T lymphocytes and cytokines such as IL-17-A,TNF-α and ICAM-1 of study group were significantly higher than those of control group(t=16.483,4.933,4.113,22.933,22.433,19.525,P<0.05),respectively,and the CD4+level was significantly lower than that of control group(t=7.773,P<0.05).The CD3+cell subsets and cytokine levels such as IL-17A,TNF-α and ICAM-1 of progression group were significantly higher than those of mitigation group(t=6.815,4.631,4.307,P<0.05),however the CD4+level was significantly lower than that of mitigation group(t=3.044,P<0.05).The results of the multivariate Logistic regression analysis showed that the decrease of CD3+expression,the increase of IL-17A expression and the increase of the area of pulmonary consolidation were the risk factors of the progress of neonatal pneumonia(β=-0.176,0.777,0.931,P<0.05),respectively.The results of the Pearson-correlation analysis showed that CD3+was negative correlation with the progression of neonatal pneumonia(r=-0.295,P<0.001),however,the IL-17A and the area of pulmonary consolidation showed a positive correlation with the progression of neonatal pneumonia(r=0.677,0.517,P<0.001).Conclusion:The CD3+expression,IL-17A of peripheral blood and the area of pulmonary consolidation are significantly predictive factors of pneumonia progression,and are closely related to the progression of pneumonia.

Group A Streptococcus (GAS) is a very important pathogen, especially for children.On a global scale, GAS is an important cause of morbidity and mortality.But the burden of disease caused by GAS is still unknown in China and also has not obtained enough attention.For this purpose, the expert consensus is comprehensively described in diagnosis, treatment and prevention of GAS diseases in children, covering related aspects of pneumology, infectiology, immunology, microbiology, cardiology, nephrology, critical care medicine and preventive medicine.Accordingly, the consensus document was intended to improve management strategies of GAS disease in Chinese children.