Agr virulence is critical for epidermal colonization and associates with atopic dermatitis development.

Atopic dermatitis (AD) is commonly associated with colonization by in the affected skin. To understand the role of in the development of AD, we performed whole-genome sequencing of strains isolated from the cheek skin of 268 Japanese infants 1 and 6 months after birth. About 45% of infants were colonized with at 1 month regardless of AD outcome.

RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility.

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmA(II), rendering TEL susceptibility.

Methylation of 23S rRNA nucleotide G748 by RlmAII methyltransferase renders Streptococcus pneumoniae telithromycin susceptible.

Several posttranscriptional modifications of bacterial rRNAs are important in determining antibiotic resistance or sensitivity. In all Gram-positive bacteria, dimethylation of nucleotide A2058, located in domain V of 23S rRNA, by the dimethyltransferase Erm(B) results in low susceptibility and resistance to telithromycin (TEL). However, this is insufficient to produce high-level resistance to TEL in Streptococcus pneumoniae.