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In vitro inhibition of esterase activity in amniotic fluid: comparison with bacterial cultures
I A Hoskins1, J Katz, F J Frieden
1Department of Obstetrics and Gynecology, New York University Medical Center, NY 10016.
Abstract:
Assessment of leukocyte esterase activity in amniotic fluid for the rapid and reliable diagnosis of chorioamnionitis has been demonstrated previously. We compared in vitro inhibition of esterase activity in amniotic fluid with bacterial cultures to identify the origins of the specific esterases released by the infecting organisms. One hundred forty-one samples were tested (90 uninfected, 51 infected). Each sample was evaluated for Gram stain, cultures, and an in vitro esterase assay followed by ebelactone inhibition. Forty-two patients had positive amniotic fluid cultures. Ebelactone produced varying degrees of inhibition of esterase activity (range, 20% to 60%) in the uninfected samples and in those infected with gram-negative organisms. There was no inhibition in the samples infected with gram-positive organisms. Thus different groups of bacteria may elicit the production of different and specific esterases in infected amniotic fluid, as shown by the differences in in vitro inhibition.
Insights
Leukocyte esterase activity in amniotic fluid can help diagnose chorioamnionitis. Different bacteria produce specific esterases, which are inhibited differently by ebelactone, aiding in infection identification.
Area of Science:
- Obstetrics and Gynecology
- Infectious Diseases
- Clinical Chemistry
Background:
- Leukocyte esterase activity in amniotic fluid is a known marker for chorioamnionitis.
- Identifying the specific esterases and their bacterial origins can improve diagnostic accuracy.
Purpose of the Study:
- To compare in vitro inhibition of amniotic fluid esterase activity with bacterial cultures.
- To identify the origins of specific esterases released by infecting organisms in cases of chorioamnionitis.
Main Methods:
- Tested 141 amniotic fluid samples (90 uninfected, 51 infected) for Gram stain and bacterial cultures.
- Performed an in vitro esterase assay followed by ebelactone inhibition for all samples.
- Analyzed inhibition patterns in relation to bacterial infection status (uninfected, Gram-negative, Gram-positive).
Main Results:
- Ebelactone inhibited esterase activity by 20%-60% in uninfected and Gram-negative infected samples.
- No significant inhibition of esterase activity was observed in samples infected with Gram-positive organisms.
- Observed varying inhibition patterns, suggesting different bacterial species elicit distinct esterase production.
Conclusions:
- Different bacterial groups may produce specific esterases in infected amniotic fluid.
- Esterase inhibition patterns can provide insights into the causative agents of chorioamnionitis.
- This approach may enhance the rapid and reliable diagnosis of chorioamnionitis.