Objective To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Methods Seventy-four 5treptococcol pyogenes involved in an outbreak of ...Objective To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Methods Seventy-four 5treptococcol pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis （PFGE）, superantigen （SAg） genes and antimicrobial susceptibility profiling were analyzed for these isolates. Results A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12（79.7%） and emml （14.9%） accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emml isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. Conclusion Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.展开更多
Objective To determine the prevalence of urolithiasis in young children fed infant formula（IF） contaminated with melamine,and the association between IF consumption and urolithiasis.Design A total of 2 733 children ...Objective To determine the prevalence of urolithiasis in young children fed infant formula（IF） contaminated with melamine,and the association between IF consumption and urolithiasis.Design A total of 2 733 children ≤3 years of age on September 1,2008 in two townships of Gansu Province,China were studied.Cases of urolithiasis were diagnosed by ultrasonography.Milk product consumption was determined by their caregivers.Remaining IF samples were tested for melamine and cyanuric acid.Results Of 2 733 eligible children in the two townships,2 186（80%） were enrolled in our study.Overall,16.6%（362） of 2 186 children had urolithiasis.The prevalence was 24.6% in children exclusively fed Sanlu brand IF,9.7% in those fed other IF,and 8.5% in those fed exclusively on other milk products.For children exclusively breast-fed,no urolithiasis was found（P0.05）.The prevalence of urolithiasis was 11.4% in children fed 400 g of Sanlu IF,rising to 37.5% in children fed over 25 600 g.Of 48 Sanlu IF samples,91.7% contained melamine（median=1 800 ppm;range=45-4 700） and 66.7% contained cyanuric acid（median=1.2 ppm;range=0.4-6.3）.Melamine was also detected in 22.2% of 36 other brand IF（median=27.5 ppm,range=4-50）.Conclusions Urolithiasis was associated with melamine-contaminated IF.Although one product caused most morbidity,other milk products may have also contributed to the outbreak.展开更多
基金supported by a fund for China Mega-Project for Infectious Disease(2011ZX10004-001)
文摘Objective To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. Methods Seventy-four 5treptococcol pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis （PFGE）, superantigen （SAg） genes and antimicrobial susceptibility profiling were analyzed for these isolates. Results A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12（79.7%） and emml （14.9%） accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emml isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. Conclusion Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.
文摘Objective To determine the prevalence of urolithiasis in young children fed infant formula（IF） contaminated with melamine,and the association between IF consumption and urolithiasis.Design A total of 2 733 children ≤3 years of age on September 1,2008 in two townships of Gansu Province,China were studied.Cases of urolithiasis were diagnosed by ultrasonography.Milk product consumption was determined by their caregivers.Remaining IF samples were tested for melamine and cyanuric acid.Results Of 2 733 eligible children in the two townships,2 186（80%） were enrolled in our study.Overall,16.6%（362） of 2 186 children had urolithiasis.The prevalence was 24.6% in children exclusively fed Sanlu brand IF,9.7% in those fed other IF,and 8.5% in those fed exclusively on other milk products.For children exclusively breast-fed,no urolithiasis was found（P0.05）.The prevalence of urolithiasis was 11.4% in children fed 400 g of Sanlu IF,rising to 37.5% in children fed over 25 600 g.Of 48 Sanlu IF samples,91.7% contained melamine（median=1 800 ppm;range=45-4 700） and 66.7% contained cyanuric acid（median=1.2 ppm;range=0.4-6.3）.Melamine was also detected in 22.2% of 36 other brand IF（median=27.5 ppm,range=4-50）.Conclusions Urolithiasis was associated with melamine-contaminated IF.Although one product caused most morbidity,other milk products may have also contributed to the outbreak.
