For example, the genome of the serotype M18 group of Streptococcus pyogenes associated with acute rheumatic fever contains 178 ORFs not present in the genomic sequence of an M1 serotype .

• 比如说，M18组的致病性链球菌（可导致急性风湿症而引起发热症状）所含有的第178号鹅口疮（致病基因）在M1组的链球菌属中就无法找到。