ObjectiveTo investigate the prevalence,antibiotic characteristics as well as molecular background of community-associated methicillin-sensitive Staphylococcus aureus (CA-MRSA) from patients with skin and sofi tissue infections from 4 different hospitals in Beijing.MethodsFive hundred and one patients were enrolled from 4 hospitals prospectively.Patients with skin and soft tissue infections and no risk factors for healthcare-associated acquisition were included.Sample from the infection sites were collected for culture.Case report form was filled out for each patient.Antibiotic susceptibility test and molecular analysis was performed for each Staphylococcus aureus isolate.ResultsTotally 164 Staphylococcus aureus isolates were cultured from the patients with skin and soft tissue infections.Of them 5 isolates were CA-MRSA.These 5 CA-MRSA isolates harbored SCCmec Ⅰ, SCCmec Ⅲ, SCCmec Ⅳ,SCCmec Ⅴ and untypable,respectively.CA-MRSA was highly resistant to β-lactamase,levofloxacin,erythromycin and clindamycin,but susceptible to vancomycin,teicoplanin,linezolid,daptomycin,and trimethoprim/sulfamethoxazole.Prevalence of PVL in community-associated methicillin sensitive Staphylococcus aureus(CA-MSSA) and CA-MRSA were 41.9％ and 2/5.Other toxins expressed similarly between them.Combined with multilocus sequence typing (MLST) and spa typing,the major clones of CA-MSSA were ST398-t034,ST7-t796,ST398-t571,ST1t127,and ST188-t189,while in CA-MRSA were ST239-t037-SCCmec Ⅰ,ST239-t632-SCCmecⅢ,ST59-t437-SCCmecV,ST8-t008-SCCmecⅣ,and ST6-t701-NT.ConclusionsThe low prevalence of CA-MRSA in Beijing and complexity of the genetic background in CA-MRSA were observed.Clone spread is not found among CA-MRSAisolates.CA-MRSAexhibithigher resistancecomparedwithmethicillinsensitive Staphylococcus aureus (MSSA).Rational drug use scheme is called in the clinical practice to prevent development of high level resistance.

Objective: To investigate the difference in intestinal microbiome between children with atopic dermatitis (AD) and healthy children. Methods: Totally, 35 children with AD were enrolled from the Department of Dermatology, Jiading Hospital of Traditional Chinese Medicine from April 2015 to April 2017, and 27 healthy children served as control group. Total DNA was extracted from the feces of the subjects, and the V3-V4 region of the 16S rRNA gene of the bacteria was amplified by PCR. High-throughput sequencing was performed using the Illumina Miseq sequencing platform to analyze the diversity of bacterial flora. The top 15 abundant bacteria were determined at phylum, genus, and species levels, and compared between the two groups. Statistical analysis was carried out using Wilcoxon rank sum test. Results: The intestinal microbiome in the two groups mainly consisted of Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria. At the phylum level, the abundance of Bacteroidetes and Fusobacteria was significantly lower in the AD group (29.16% ± 19.96%, 0.06% ± 0.17%, respectively) than in the healthy control group (39.06% ± 15.98%, 0.50% ± 1.71%, respectively, P = 0.042, 0.041) . At the genus level, the abundance of Bacteroides was significantly lower in the AD group (23.77% ± 18.08%) than in the healthy control group (33.1% ± 15.75%, P = 0.029) . There was no significant difference in the distribution of the top 15 abundant species between the two groups (all P > 0.05) . Conclusion There are some differences in the composition of intestinal microbiome and relative abundance of bacteria between children with AD and healthy children.