with Cp-1 as its first member. Dp-1 and Cp-1 infect both S. pneumoniae and S. mitis. However, the host ranges of most Streptococcus phages have not been investigated systematically. Natural genetic transformation Natural genetic transformation involves the transfer of DNA from one bacterium to another through the surrounding medium. Transformation is a complex process dependent on expression of numerous genes. To be capable of transformation a bacterium must enter a special physiologic state referred to as competence. S. pneumoniae, S. mitis and S. oralis can become competent, and as a result actively acquire homologous DNA for transformation by a predatory fratricidal mechanism This fratricidal mechanism mainly exploits non-competent siblings present in the same niche Among highly competent isolates of S. pneumoniae, Li et al. showed that nasal colonization fitness and virulence (lung infectivity) depend on an intact competence system. Competence may allow the streptococcal pathogen to use external homologous DNA for recombinational repair of DNA damages caused by the hosts oxidative attack. See also Cia-dependent small RNAs Quellung reaction Streptococcal infection in poultry Streptococcal pharyngitis Streptokinase References External links Nature-Inspired CRISPR Enzyme Discoveries Vastly Expand Genome Editing . On: SciTechDaily. June 16, 2020. Source: Media Lab, Massachusetts Institute of Technology. Streptococcus genomes and related information at PATRIC, a Bioinformatics Resource Center funded by NIAID The Canadian Strep B Foundation The UK Group B Strep Support charity Streptococcaceae Gut flora bacteria Gram-positive bacteria Bacteria genera Pathogenic bacteria