Hoe Nancy P, Fullerton Kathleen E, Liu Mengyao, Peters John E, Gackstetter Gary D, Adams Gerald J, Musser James M
Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.
J Infect Dis. 2003 Sep 15;188(6):818-27. doi: 10.1086/377644. Epub 2003 Sep 4.
Contemporary molecular genetic analysis methods have not been used to study large samples of carriage isolates of group A Streptococcus. To determine the emm types causing asymptomatic carriage and pharyngitis in a closed population, we analyzed 675 isolates recovered from a population-based surveillance study of 10,634 recruits at Lackland Air Force Base, Texas, during 4 months in 1993-1994. Strains with emm1 and emm6 alleles accounted for only 22% of the isolates recovered from asymptomatic recruits at entrance to training. However, these 2 emm types caused 69% of the pharyngitis cases identified during training and represented 51% of the isolates recovered from the throat on exit from training. Sequence analysis of the hypervariable sic gene documented that distinct emm1 subclones disseminated in specific training groups called flights. The preferential increase in the prevalence of emm1 and emm6 isolates during the 6-week training period indicates an enhanced ability of these strains to disseminate and cause disease in this population.
当代分子遗传学分析方法尚未用于研究A组链球菌携带菌株的大样本。为了确定在一个封闭人群中导致无症状携带和咽炎的emm型，我们分析了1993 - 1994年4个月期间从得克萨斯州拉克兰空军基地10634名新兵的人群监测研究中获得的675株菌株。携带emm1和emm6等位基因的菌株仅占新兵入伍时无症状携带者分离株的22%。然而，这两种emm型导致了训练期间确诊的咽炎病例的69%，并且占训练结束时从咽喉分离出的菌株的51%。高变sic基因的序列分析表明，不同的emm1亚克隆在称为飞行小队的特定训练组中传播。在为期6周的训练期间，emm1和emm6分离株的患病率优先增加，表明这些菌株在该人群中传播和致病的能力增强。
