Antimicrobial factors in the cervical mucus plug.
OBJECTIVE
The cervical mucus plug is positioned between the microbe-rich vagina and the normally sterile uterine cavity, which suggests a host defense function, but few relevant data are available. We analyzed the composition and antimicrobial activity of cervical mucus plugs.


METHODS
Cervical mucus plugs were collected from healthy women at delivery. Groups of plugs were randomly selected for electrolyte analysis, antimicrobial activity assays against group B Streptococcus, Escherichia coli, Candida albicans, and assays of known antimicrobial polypeptides.


RESULTS
Both intact cervical mucus plugs and their aqueous extracts exhibited antimicrobial activity against aerobic microbes, in the order of potency: group B Streptococcus > E coli > C albicans. Semiquantitative Western blotting of extracts showed that secretory leukoprotease inhibitor, lysozyme, lactoferrin, and neutrophil defensins were present at concentrations that were sufficient for antimicrobial activity.


CONCLUSIONS
The cervical mucus plug is not only a mechanical but also a chemical barrier to infection that ascends from the vagina.
Department of Obstetrics and Gynecology, Aarhus University Hospital, Denmark.
Merete
M
Hein
Erika V
EV
Valore
Rikke Bek
RB
Helmig
Niels
N
Uldbjerg
Tomas
T
Ganz
D000890:Anti-Infective Agents / Q000032:analysis*; D023181:Antimicrobial Cationic Peptides / Q000032:analysis*; D015153:Blotting, Western; D002582:Cervix Mucus / Q000737:chemistry* / Q000378:metabolism / Q000382:microbiology; D004573:Electrolytes / Q000032:analysis; D005260:Female; D006801:Humans; D009113:Muramidase / Q000032:analysis / Q000378:metabolism; D011247:Pregnancy; D011506:Proteins / Q000032:analysis
D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D004573:Electrolytes; D011506:Proteins; D009113:Muramidase