Erythromycin resistant genes in Streptococcus pyogenes of children in Shanghai / 中华传染病杂志

ABSTRACT

Objective To understand the erythromycin resistance rate and the erythromycin resistant gene spectrum in Streptococcus pyogenes strains isolated in Shanghai.Methods The outpatient children who were diagnosed with scarlatinal in the Children's Hospital of Fudan University from November 2004 to June 2006 were enrolled and 100 strains of Streptococcus pyogenes were isolated by pharyngeal swab culture.The distributions ofermA,ermB,mefA genes were determined by polymerase chain reaction(PCR)amplification.The relationship between ermA,ermB,mefA genes and erythromycin resistance were also analyzed.Results The erythromycin and clindamycin resistance rates of Streptococcus pyogenes in Shanghai were 98%and 95%,respectively;the concordance rate of these two drugs was 97%.Among 100 strains of Streptococcus pyogenes,94 strains(94%)contained ermB gene,with 100%of erythromycinresistance rate.Sixteen(16%)contained mefA gene,with 100% of erythromycin resistance rate.ermA was not detected inall the 100 strains.The ermB and mefA genes were not found in 5 strains,among which,2 were susceptible to erythromycin and 3wereresistant to erythromycin.Only 1%of isolates was mefA genesingle positive.Conclusions There is a high erythromycin resistance rate of Streptococcus pyogenes strains isolated inShanghai,and the cross resistance to clindamycin is high.TheermB gene is important erythromycin resistancedeterminants of Streptococcus pyogenes in Shanghai.