Study the effects of escherichia coli inoculation on human sperm parameters

Maryam Ahmadian mahmodabadi,1 Nassim ghorbanmehr,2,* Mansoureh movahedin,3 Ameneh elikaei,4 Farzaneh heydari,5

1. Biotechnology Department, Faculty of Biological Sciences, Alzahra University
2. Biotechnology Department, Faculty of Biological Sciences, Alzahra University
3. Anatomical sciences Department, Medical Sciences Faculty, Tarbiat Modares University
4. Microbiology Department, Faculty of Biological Sciences, Alzahra University
5. Human I.V.F. Clinic, Nikan Hospital



Genital tract infection (gti) is one of the most important causes of male infertility. recent studies show that infections are the reason of almost 15% of male infertility cases. the most frequently isolated bacterium in the ejaculation of infertile men is escherichia coli (e.coli). in addition to indirect effects of bacterial infection on sperm quality and function which are mediated by leukocyte activation, it is proposed that these microbial agents can also affect sperm cells directly. finding out how bacterial species interact with the sperm cells plays an important role in the treatment of infertile men with bacteriospermia. the aim of this study was to examine an in vitro direct effect of e.coli on ejaculated human spermatozoa and comparing sperm parameters (motility, morphology, and viability) with and without adding bacteria to the sperm samples.


The study was carried out on swim-up-separated spermatozoa from 32 normozoospermic samples of men referred to the infertility treatment center, nikan hospital, tehran. after removal of seminal plasma, the sperm suspension of each sample was divided in to two parts; the first part (experimental group) was co-incubated in htf-hsa solution with 5×106cfu/ml e. coli atcc25922 for 90 minutes at 37°c, the second part (control group) was incubated at the same condition but without e.coli. sperm parameters were assessed according to world health organization criteria. paired t-test was used to find the significant differences between the experimental group and control group.


There were significant differences in sperm motility, morphology and viability between experimental and control groups (p<0.05). occasionally, sperm agglutination mediated by e. coli was also observed in experimental group.


Our data suggests that inoculation of escherichia coli to semen samples can affects sperm quality and function, it seems that the bacterial infection can negatively affects semen samples quality.


Sperm; bacterial infections; e.coli; male infertility