100 bp plus dna ladder marker

Detection of virulence genes (ply, pasA, lytA, pspA) and pili genes (rlrA for PI-1and sipA for PI-2) of pneumococcal isolates were amplified using PCR and all primers, PCR reactions and conditions used were as previously described [17 (link)]. The 100 bp plus DNA ladder marker (Takara, China) was used for molecular weight reference.

Pneumolysin and autolysin are encoded by the ply and lytA genes, respectively, which can enhance the virulence of S. pneumoniae. Additionally, pneumolysin binds membrane cholesterol and forms transmembrane pores that lead to cell lysis [22 (link)]. Pneumococcal surface protein A is one of surface-exposed choline binding proteins, which is encoded by pspA gene and presents almost in all pneumococcal isolates [23 (link)]. The pavA gene of S. pneumoniae encodes a fibronectin-binding protein, which is crucial for virulence [24 (link)]. The cbpA and cbpG genes encode choline binding proteins that promote the colonization of the nasopharynx [25 (link)].
The virulence genes (ply, lytA, pspA, pavA, cbpA, cbpG) and pilus genes (rlrA and sipA) of S. pneumoniae were amplified using PCR. The primers, PCR reactions and conditions were used as previously described [26 (link)]. The 100-bp plus DNA ladder marker (Takara, Dalian, China) was used for estimating molecular weight.