Effect of bacterial infection on sperm quality and DNA fragmentation in subfertile men with Leukocytospermia

Abstract

Background Although bacterial infections have been recognized as a possible cause of male infertility, the effect of bacterial infections on sperm quality and sperm DNA fragmentation remains controversial. The current study aimed to investigate the prevalence rate of bacterial infection in subfertile men and its effect on semen quality. Seminal fluid was collected from 172 male members of infertile couples attending the andrology infertility center and a group of 35 fertile subjects as a control. Sperm parameters and DNA fragmentation were evaluated based on the type of bacteria in all ejaculates. Results From the 172 patients investigated for infertility, 60 (34.88%) patients had a positive culture for pathogenic bacteria of different species. Leukocytospermia was significantly higher in infected samples in comparison with non-infected samples (p < 0.05). Sperm concentration and motility and morphology were significantly lower in infected than non-infected samples. Moreover, sperm DNA fragmentation was significantly higher in infected than non-infected samples. Besides, our results showed that sperm DNA fragmentation was correlated significantly with leukocytospermia (R: 0.22, p < 0.01). Conclusion The present study suggested that bacterial infection significantly correlated with leukocytospermia could impair male fertility potential through decreasing sperm motility, morphology, and DNA integrity.

Possible Implications of Bacteriospermia on the Sperm Quality, Oxidative Characteristics, and Seminal Cytokine Network in Normozoospermic Men

“…The effects of bacteria on the resulting semen quality are multivariable and have been reported by several studies [ 3 , 5 , 6 , 7 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Most of the reports agree that bacteriospermia may be accompanied by alterations to the sperm motion and membrane integrity [ 3 , 6 , 10 , 11 ], aberrations to the sperm head, mid-piece, or tail, premature acrosome reaction [ 5 , 10 , 12 , 13 ], deterioration of the energy metabolism [ 3 , 5 , 7 ], DNA fragmentation and phosphatidylserine dislocation [ 10 , 14 , 15 ]. Bacterial adhesion and a subsequent sperm agglutination [ 5 , 11 , 15 , 16 , 17 ] alongside reactive oxygen species (ROS) outbursts and lipid peroxidation (LPO) [ 18 , 19 , 20 , 21 ] have also been suggested to be associated with bacteriospermia.…”

“…[ 1 ]. While the most prevalent bacteria acknowledged to cause urogenital infections and subsequent bacteriospermia include Escherichia coli ( E. coli ), Staphylococcus aureus ( S. aureus ), Ureaplasma urealyticum , Chlamydia trachomatis , Enterococcus faecalis ( E. faecalis ), Mycoplasma and streptococci [ 2 , 4 , 5 ], the male reproductive system is not entirely sterile, as it has been already reported that certain bacteria, such as Staphylococcus capitis ( S. capitis ), Staphylococcus epidermidis ( S. epidermidis ) or Staphylococcus hominis ( S. hominis ) are present in otherwise normozoospermic and fertile subjects [ 6 , 7 , 8 ]. What is more, even in healthy males, semen may become contaminated by microorganisms as it passes through the urogenital system beginning from the testes and moving onward to the penile foreskin [ 6 ].…”

“…Most of the reports agree that bacteriospermia may be accompanied by alterations to the sperm motion and membrane integrity [ 3 , 6 , 10 , 11 ], aberrations to the sperm head, mid-piece, or tail, premature acrosome reaction [ 5 , 10 , 12 , 13 ], deterioration of the energy metabolism [ 3 , 5 , 7 ], DNA fragmentation and phosphatidylserine dislocation [ 10 , 14 , 15 ]. Bacterial adhesion and a subsequent sperm agglutination [ 5 , 11 , 15 , 16 , 17 ] alongside reactive oxygen species (ROS) outbursts and lipid peroxidation (LPO) [ 18 , 19 , 20 , 21 ] have also been suggested to be associated with bacteriospermia. Moreover, bacterial infiltration to the male reproductive system has been shown to trigger a local immune reaction that is usually accompanied by the release of cytokines and leukocytospermia [ 1 , 3 , 7 , 19 , 22 , 23 , 24 , 25 ], which have been often associated with a decline of male reproductive performance.…”

The Impact of Bacteriocenoses on Sperm Vitality, Immunological and Oxidative Characteristics of Ram Ejaculates: Does the Breed Play a Role?

“…Previous studies on human and animal ejaculates have indicated that bacteriospermia may lead to sperm agglutination [ 6 , 7 ] and subsequent sub-standard sperm motility [ 8 , 9 , 10 ]. Furthermore, a greater proportion of spermatozoa with alterations to the membranous structures and morphological defects has been found in ejaculates contaminated with bacteria [ 9 , 10 , 11 , 12 ]. At the same time, it has been reported that bacteriospermia may induce an imbalance in the seminal oxidative balance, by accelerating reactive oxygen species (ROS) overproduction [ 13 ], an excessive release of pro-inflammatory cytokines, and subsequent damage to the sperm structures crucial for the male gamete to reach the oocyte and successfully accomplish fertilization [ 10 , 14 ].…”

Identification of Bull Semen Microbiome by 16S Sequencing and Possible Relationships with Fertility

“…However, bacteria can have a direct negative affect on sperm quality, depending on the species and number. Negative correlations were reported between certain bacteria and sperm motility [10], viability, membrane integrity and acrosome reaction [11], sperm DNA fragmentation rates [12,13] and the total number of spermatozoa [14,15]. Givens and Marley [16] reported the presence of microorganisms that cause infertility and/or are transmitted via semen.…”