[HTML][HTML] Cervicovaginal fluid and semen block the microbicidal activity of hydrogen peroxide produced by vaginal lactobacilli
DE O'Hanlon, BR Lanier, TR Moench, RA Cone - BMC infectious diseases, 2010 - Springer
DE O'Hanlon, BR Lanier, TR Moench, RA Cone
BMC infectious diseases, 2010•SpringerBackground H 2 O 2 produced by vaginal lactobacilli is believed to protect against infection,
and H 2 O 2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution.
However, cervicovaginal fluid (CVF) and semen have significant H 2 O 2-blocking activity.
Methods We measured the H 2 O 2 concentration of CVF and the H 2 O 2-blocking activity of
CVF and semen using fluorescence and in vitro bacterial-exposure experiments. Results
The mean H 2 O 2 measured in fully aerobic CVF was 23±5 μM; however, 50 μM H 2 O 2 in …
and H 2 O 2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution.
However, cervicovaginal fluid (CVF) and semen have significant H 2 O 2-blocking activity.
Methods We measured the H 2 O 2 concentration of CVF and the H 2 O 2-blocking activity of
CVF and semen using fluorescence and in vitro bacterial-exposure experiments. Results
The mean H 2 O 2 measured in fully aerobic CVF was 23±5 μM; however, 50 μM H 2 O 2 in …
Background
H2O2 produced by vaginal lactobacilli is believed to protect against infection, and H2O2-producing lactobacilli inactivate pathogens in vitro in protein-free salt solution. However, cervicovaginal fluid (CVF) and semen have significant H2O2-blocking activity.
Methods
We measured the H2O2 concentration of CVF and the H2O2-blocking activity of CVF and semen using fluorescence and in vitro bacterial-exposure experiments.
Results
The mean H2O2 measured in fully aerobic CVF was 23 ± 5 μM; however, 50 μM H2O2 in salt solution showed no in vitro inactivation of HSV-2, Neisseria gonorrhoeae, Hemophilus ducreyii, or any of six BV-associated bacteria. CVF reduced 1 mM added H2O2 to an undetectable level, while semen reduced 10 mM added H2O2 to undetectable. Moreover, the addition of just 1% CVF supernatant abolished in vitro pathogen-inactivation by H2O2-producing lactobacilli.
Conclusions
Given the H2O2-blocking activity of CVF and semen, it is implausible that H2O2-production by vaginal lactobacilli is a significant mechanism of protection in vivo.
Springer