High correlation of the presence of methyladenine in Neisseria gonorrhoeae DNA with the AHU auxotype.

Strains of Neisseria gonorrhoeae were tested for the presence of methyladenine in the DNA sequence GATC by using the site-specific restriction endonucleases MboI and DpnI. It was found that 43 of 83 strains tested contained methylated DNA. When methylation was compared with the auxotype of the organism, 35 of 35 strains with the AHU (arginine-, hypoxanthine-, and uracil-requiring) auxotype and 8 of 48 strains with other auxotypes contained methyladenine. When the incidence of methylation in strains isolated from patients suffering from disseminated gonococcal infection was compared with that in strains isolated from patients suffering from uncomplicated gonococcal infection, no correlation with methylation and disseminated gonococcal infection was observed.