RT Journal Article SR Electronic T1 Attachment of Neisseria gonorrhoeae to human sperm. Microscopical study of trypsin and iron. JF The British Journal of Venereal Diseases JO Br J Vener Dis FD BMJ Publishing Group Ltd SP 245 OP 255 DO 10.1136/sti.55.4.245 VO 55 IS 4 A1 C I Gomez A1 W A Stenback A1 A N James A1 B S Criswell A1 R P Williams YR 1979 UL http://sti.bmj.com/content/55/4/245.abstract AB Pilated Neisseria gonorrhoeae of colony type 1 (T1) and non-pilated bacteria of colony type 4 (T4) were observed by transmission (TEM) and scanning electron microscopy (SEM). No pili were observed on T4 gonogocci, but two types of pili--straight, type a, and bent, type b--were seen on T1 by TEM. When incubated with human sperum and examined by either TEM or SEM, T1 gonococci were seen to attach by individual pili, by several pili wound together as a rope, or by direct contact. Gonococci from T4 colonies attached only by direct contact. Treatment with typsin (1 mg/ml) damaged or removed pili from gonococci. After incubation with trypsin, attachment of pilated gonococci to sperm was decreased significantly, but such treatment did not affect attachment of non-pilated gonococci. Incubation of gonococci from either colony type in 0.1 mmol/l ferric nitrate, followed by incubation with sperm, significantly increased attachment of only T4 bacteria. No pili were seen on T4 gonococci treated with ferric nitrate; thus, it appears that factors other than pili alone are concerned in attachment of these gonococci to sperm.