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Differential attachment by piliated and nonpiliated Neisseria gonorrhoeae to human sperm
Abstract:
Piliated type 1 Neisseria gonorrhoeae attached to 50% of human sperm after incubation of mixtures in vitro for 15 min at 35 C. In contrast, nonpiliated type 4 N. gonorrhoeae attached to only 23% of sperm. Similar results were obtained with three different strains of N. gonorrhoeae. Treatment with heat or formaldehyde to kill bacteria did not affect the amount of attachment by piliated or nonpiliated types. Escherichia coli and N. subflava, other species of piliated bacteria, attached to about 40% of sperm, and the nonpiliated species N. meningitidis and N. catarrhalis attached to a comparable number of sperm, as did type 4 N. gonorrhoeae. Prior incubation of type 1 N. gonorrhoeae with purified antibody prepared against gonococcal pili reduced the percentage of sperm with attached bacteria to the same level as that for nonpiliated type 4 gonococci. Similar treatment of other piliated organisms or of nonpiliated Neisseria did not affect the attachment of the bacteria to sperm.
Insights
Piliated Neisseria gonorrhoeae (gonococcus) readily attach to human sperm, while nonpiliated strains show significantly less attachment. This bacterial pili-mediated attachment is specific to gonococci.
Area of Science:
- Microbiology
- Reproductive Health
- Bacterial Pathogenesis
Background:
- Neisseria gonorrhoeae is a bacterium that causes the sexually transmitted infection gonorrhea.
- The interaction between Neisseria gonorrhoeae and human sperm is not fully understood, particularly the role of bacterial structures in this interaction.
Purpose of the Study:
- To investigate the role of pili in the attachment of Neisseria gonorrhoeae to human sperm.
- To compare the attachment efficiency of piliated and nonpiliated Neisseria gonorrhoeae strains to human sperm.
Main Methods:
- In vitro incubation of human sperm with various strains of Neisseria gonorrhoeae (piliated and nonpiliated).
- Assessment of bacterial attachment to sperm by quantifying the percentage of sperm with attached bacteria.
- Use of heat-killed bacteria and antibody treatment to elucidate the mechanism of attachment.
Main Results:
- Piliated type 1 Neisseria gonorrhoeae attached to 50% of human sperm, whereas nonpiliated type 4 strains attached to only 23%.
- Attachment was specific to gonococcal pili, as antibody treatment against pili reduced attachment of piliated Neisseria gonorrhoeae.
- Other piliated and nonpiliated bacteria showed varying degrees of attachment, but Neisseria gonorrhoeae's piliated form demonstrated a distinct interaction.
Conclusions:
- Bacterial pili are crucial for the efficient attachment of Neisseria gonorrhoeae to human sperm.
- The findings suggest a specific mechanism for gonococcal adherence to sperm, potentially impacting sperm function or transport.