Ability of Escherichia coli to produce hemolysis leads to a greater pathogenic effect on human sperm

Hemolytic Escherichia coli demonstrated a strain-dependent effect, altering all sperm variables studied, in contrast to nonhemolytic strains, which differentially impair sperm function.

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Authors

Rodrigo Boguen, M.Sc., Favian Treulen, M.Sc., Pamela Uribe, M.Sc., Juana V. Villegas, Ph.D.

Volume 103, Issue 5, Pages 1155-1161

Abstract

Objective:

To determine the effect on human sperm of Escherichia coli strains separated on the basis of their ability to produce hemolysis.

Design:

Experimental study.

Setting:

University-based laboratory.

Patient(s):

Semen samples from healthy donors.

Intervention(s):

Five million sperm, selected via the swim-up method, were incubated with 3 E. coli concentrations to obtain ratios of sperm to E. coli of 1:2, 1:16, and 1:128. The E. coli strains were: a hemolytic isolated strain (H), a nonhemolytic American Type Culture Collection strain (NH-ATCC), and a nonhemolytic isolated strain (NH-I).

Main Outcome Measure(s):

Aliquots of human sperm were used to measure progressive motility using computer-aided sperm analysis, mitochondrial membrane potential (ΔΨm) with a JC-1 (5,5′,6,6′ tetrachloro-1,1′,3,3′-tetraethylbenzamidazolocarbocyanin iodide) and propidium iodide stain, and intracellular reactive oxygen species (iROS) with a dihydroethidium (DHE) stain. Sperm ΔΨm and iROS were measured by flow cytometry. Sperm vitality was considered the mean of propidium iodide–negative and DHE-negative cells.

Result(s):

Sperm incubated with the H strain in a 1:2 sperm to bacteria ratio demonstrated a significant decrease in motility and ΔΨm, and an increase of iROS. The NH-ATCC strain decreased sperm motility and ΔΨm, but in a ratio of sperm to bacteria of 1:128; it increased iROS at a ratio of 1:16. The NH-I strain did not affect the analyzed sperm functions, even at a 1:128 sperm to bacteria ratio.

Conclusion(s):

Results show a greater pathogenic effect on human sperm of E. coli strains with, versus without, hemolytic capacity.

Read the full text at: http://www.fertstert.org/article/S0015-0282(15)00091-6/fulltext


Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders. The journal publishes juried original scientific articles in clinical and laboratory research relevant to reproductive endocrinology, urology, andrology, physiology, immunology, genetics, contraception, and menopause. Fertility and Sterility® encourages and supports meaningful basic and clinical research, and facilitates and promotes excellence in professional education, in the field of reproductive medicine.

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