Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to inv...Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.展开更多
目的:分析重庆地区扁桃体炎患儿A族链球菌(Group A streptococcus,GAS)分离株emm分型、红霉素耐药基因和超抗原基因相关性。方法:收集2007年重庆地区扁桃体炎患儿GAS分离株44株。对44株菌株进行emm分型,红霉素耐药基因ermB、ermTR和mef...目的:分析重庆地区扁桃体炎患儿A族链球菌(Group A streptococcus,GAS)分离株emm分型、红霉素耐药基因和超抗原基因相关性。方法:收集2007年重庆地区扁桃体炎患儿GAS分离株44株。对44株菌株进行emm分型,红霉素耐药基因ermB、ermTR和mefA以及8种超抗原基因(ssa、SMEZ、speA、speC、speG、speH、speI、speJ)检测。结果:儿童扁桃体炎GAS分离株emm分型以emm12最多见,共26株(占59.1%);其次为emm1,共7株(占15.9%);少见的emm型为emm22有2株,emm6有2株,emm3有2株,emm80、emm63、emm102、stG485和st1815分别各有1株。44株GAS菌株均检出耐药基因ermB(100%),33株检出耐药基因ermTR(75.0%),3株检出耐药基因mefA(6.8%)。44株菌株均检出ssa、SMEZ和speH超抗原基因,其余5种超抗原基因检出率依次为speG37株(84.1%),speC36株(81.8%),speI28株(63.6%),speA22株(50%),speJ7株(15.9%)。7株emm1菌株有6株检出speA基因(占85.7%),26株emm12菌株有7株检出speA基因(占26.9%),speA基因分布在emm1、emm12分布中的差异具有统计学意义(P=0.008,<0.05);耐药基因ermB、ermTR和mefA在不同的emm型中分布是随机的,emm分型和耐药基因之间未发现明显相关性。结论:重庆地区儿童扁桃体炎GAS分离株emm分型以emm12和emm1为主;对红霉素的耐药机制以ermB编码为主的23SrRNA甲基化酶致靶位改变为主;emm型与大环内酯类抗生素耐药基因分布无明显相关性;speA超抗原基因分布主要与emm1相关。展开更多
This study aimed to investigate the carriage of Streptococcus pyogenes in population vulnerable to scarlet fever and to compare their genotypic characterization between different age groups. Pharyngeal swabs were coll...This study aimed to investigate the carriage of Streptococcus pyogenes in population vulnerable to scarlet fever and to compare their genotypic characterization between different age groups. Pharyngeal swabs were collected from 120 - 150 students in each of the three districts in Shanghai in May and December during 2015 to 2017, while emm typing and detection of 12 superantigen genes were performed to characterize the isolates. During 2015-2017, the average carriage rate in students was 5.7% (135/2,371), without significant difference between different years or districts. The carriage rate was significantly different between children from the three age groups, with 2.4% in 3 - 4 years, 5.4% in 5 - 9 years, and 9.1% in 10 - 14 years. Eight emm types were found, including emm 1, emm 4, emm 12, emm 22, emm 75, emm 89, emm 70 and emm 241, among which emm 12 accounted for 60%, and emm 1 27.5%. The predominance of emm 12 was found in each year, but the proportion of emm 12 was lower in 10 - 14 years (43.3%) than in 3 - 4 years (86.7%) and in 5 - 9 years (73.3%) (P = 0.002 and 0.003). Superantigen genes of speB, speC, speG, ssa and smeZ were found in almost all the isolates. The average carriage of S. pyogenes in population vulnerable to scarlet fever was 5.7% in Shanghai, highest in 10 - 14 years (9.1%), while emm 12 was the predominant type.展开更多
文摘Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.
文摘目的:分析重庆地区扁桃体炎患儿A族链球菌(Group A streptococcus,GAS)分离株emm分型、红霉素耐药基因和超抗原基因相关性。方法:收集2007年重庆地区扁桃体炎患儿GAS分离株44株。对44株菌株进行emm分型,红霉素耐药基因ermB、ermTR和mefA以及8种超抗原基因(ssa、SMEZ、speA、speC、speG、speH、speI、speJ)检测。结果:儿童扁桃体炎GAS分离株emm分型以emm12最多见,共26株(占59.1%);其次为emm1,共7株(占15.9%);少见的emm型为emm22有2株,emm6有2株,emm3有2株,emm80、emm63、emm102、stG485和st1815分别各有1株。44株GAS菌株均检出耐药基因ermB(100%),33株检出耐药基因ermTR(75.0%),3株检出耐药基因mefA(6.8%)。44株菌株均检出ssa、SMEZ和speH超抗原基因,其余5种超抗原基因检出率依次为speG37株(84.1%),speC36株(81.8%),speI28株(63.6%),speA22株(50%),speJ7株(15.9%)。7株emm1菌株有6株检出speA基因(占85.7%),26株emm12菌株有7株检出speA基因(占26.9%),speA基因分布在emm1、emm12分布中的差异具有统计学意义(P=0.008,<0.05);耐药基因ermB、ermTR和mefA在不同的emm型中分布是随机的,emm分型和耐药基因之间未发现明显相关性。结论:重庆地区儿童扁桃体炎GAS分离株emm分型以emm12和emm1为主;对红霉素的耐药机制以ermB编码为主的23SrRNA甲基化酶致靶位改变为主;emm型与大环内酯类抗生素耐药基因分布无明显相关性;speA超抗原基因分布主要与emm1相关。
文摘This study aimed to investigate the carriage of Streptococcus pyogenes in population vulnerable to scarlet fever and to compare their genotypic characterization between different age groups. Pharyngeal swabs were collected from 120 - 150 students in each of the three districts in Shanghai in May and December during 2015 to 2017, while emm typing and detection of 12 superantigen genes were performed to characterize the isolates. During 2015-2017, the average carriage rate in students was 5.7% (135/2,371), without significant difference between different years or districts. The carriage rate was significantly different between children from the three age groups, with 2.4% in 3 - 4 years, 5.4% in 5 - 9 years, and 9.1% in 10 - 14 years. Eight emm types were found, including emm 1, emm 4, emm 12, emm 22, emm 75, emm 89, emm 70 and emm 241, among which emm 12 accounted for 60%, and emm 1 27.5%. The predominance of emm 12 was found in each year, but the proportion of emm 12 was lower in 10 - 14 years (43.3%) than in 3 - 4 years (86.7%) and in 5 - 9 years (73.3%) (P = 0.002 and 0.003). Superantigen genes of speB, speC, speG, ssa and smeZ were found in almost all the isolates. The average carriage of S. pyogenes in population vulnerable to scarlet fever was 5.7% in Shanghai, highest in 10 - 14 years (9.1%), while emm 12 was the predominant type.
