Mechanism of sperm immobilization by Escherichia coli

Leukocytospermia and/or Bacteriospermia: Impact on Male Infertility

Infertility is a globally underestimated public health concern affecting almost 190 million people, i.e., about 17.5% of people during their lifetime, while the prevalence of male factor infertility is about 7%. Among numerous other causes, the prevalence of male genital tract infections reportedly ranges between 10% and 35%. Leukocytospermia is found in 30% of infertile men and up to 20% in fertile men. Bacterial infections cause an inflammatory response attracting leukocytes, which produce reactive oxygen species (ROS) and release cytokines, both of which can cause damage to sperm, rendering them dysfunctional. Although leukocytospermia and bacteriospermia are both clinical conditions that can negatively affect male fertility, there is still debate about their impact on assisted reproduction outcomes and management. According to World Health Organization (WHO) guidelines, leukocytes should be determined by means of the Endtz test or with monoclonal antibodies against CD15, CD68 or CD22. The cut-off value proposed by the WHO is 1 × 106 peroxidase-positive cells/mL. For bacteria, Gram staining and semen culture are regarded as the "gold standard", while modern techniques such as PCR and next-generation sequencing (NGS) are allowing clinicians to detect a wider range of pathogens. Whereas the WHO manual does not specify a specific value as a cut-off for bacterial contamination, several studies consider semen samples with more than 103 colony-forming units (cfu)/mL as bacteriospermic. The pathogenic mechanisms leading to sperm dysfunction include direct interaction of bacteria with the male germ cells, bacterial release of spermatotoxic substances, induction of pro-inflammatory cytokines and ROS, all of which lead to oxidative stress. Clinically, bacterial infections, including "silent" infections, are treatable, with antibiotics being the treatment of choice. Yet, non-steroidal antiphlogistics or antioxidants should also be considered to alleviate inflammatory lesions and improve semen quality. In an assisted reproduction set up, sperm separation techniques significantly reduce the bacterial load in the semen. Nonetheless, contamination of the semen sample with skin commensals should be prevented by applying relevant hygiene techniques. In patients where leukocytospermia is detected, the causes (e.g. infection, inflammation, varicocele, smoking, etc.) of the leukocyte infiltration have to be identified and addressed with antibiotics, anti-inflammatories or antioxidants in cases where high oxidative stress levels are detected. However, no specific strategy is available for the management of leukocytospermia. Therefore, the relationship between bacteriospermia and leukocytospermia as well as their specific impact on functional sperm parameters and reproductive outcome variables such as fertilization or clinical pregnancy must be further investigated. The aim of this narrative review is to provide an update on the current knowledge on leukocytospermia and bacteriospermia and their impact on male fertility.

Sperm in the Mammalian Female Reproductive Tract: Surfing Through the Tract to Try to Beat the Odds

Mammalian sperm are deposited in the vagina or the cervix/uterus at coitus or at artificial insemination, and the fertilizing sperm move through the female reproductive tract to the ampulla of the oviduct, the site of fertilization. But the destination of most sperm is not the oviduct. Most sperm are carried by retrograde fluid flow to the vagina, are phagocytosed, and/or do not pass barriers on the pathway to the oviduct. The sperm that reach the site of fertilization are the exceptions and winners of one of the most stringent selection processes in nature. This review discusses the challenges sperm encounter and how the few sperm that reach the site of fertilization overcome them. The sperm that reach the goal must navigate viscoelastic fluid, swim vigorously and cooperatively along the walls of the female tract, avoid the innate immune system, and respond to potential cues to direct their movement.

Curcumin Attenuates Damage to Rooster Spermatozoa Exposed to Selected Uropathogens

Artificial insemination, as an essential pillar of the modern poultry industry, primarily depends on the quality of semen collected from stud roosters. Since the collection and storage of ejaculates is not a sterile process, antimicrobial agents have become essential supplements to semen extenders. While the use of traditional antibiotics has been challenged because of rising bacterial resistance, natural biomolecules represent an appealing alternative because of their antibacterial and antioxidant properties. As such, this study strived to compare the effects of 50 μmol/L curcumin (CUR) with 31.2 µg/mL kanamycin (KAN) as a conventional antibiotic on rooster sperm quality in the presence of Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. Changes in sperm structural integrity and functional activity were monitored at 2 and 24 h of culture. Computer-assisted semen analysis revealed significant sperm motility preservation following treatment with KAN, particularly in the case of Salmonella enterica and Pseudomonas aeruginosa (p < 0.001) after 24 h. On the other hand, CUR was more effective in opposing ROS overproduction by all bacteria (p < 0.05), as determined by luminol-based luminometry, and maintained sperm mitochondrial activity (p < 0.001 in the case of Salmonella enterica; p < 0.05 with respect to Escherichia coli and Pseudomonas aeruginosa), as assessed by the fluorometric JC-1 assay. The TUNEL assay revealed that CUR readily preserved the DNA integrity of rooster sperm exposed to Salmonella enterica (p < 0.01) and Escherichia coli (p < 0.001). The bacteriological analysis showed higher efficiency of KAN in preventing the growth of all selected bacterial species (p < 0.0001) as opposed to CUR. In conclusion, CUR provided protection to rooster spermatozoa against alterations caused by uropathogens, most likely through its antioxidant activity. Hence, CUR supplementation to poultry semen extenders in combination with properly selected antibacterial substances may become an interesting strategy in the management of bacterial contamination during semen storage.

Bacteriospermia - A formidable player in male subfertility

Bacterial colonization of male reproductive tissues, cells, and fluids, and the subsequent impact of bacteria on the sperm architecture, activity, and fertilizing potential, has recently gained increased attention from the medical and scientific community. Current evidence strongly emphasizes the fact that the presence of bacteria in semen may have dire consequences on the resulting male fertility. Nevertheless, the molecular basis underlying bacteriospermia-associated suboptimal semen quality is sophisticated, multifactorial, and still needs further understanding. Bacterial adhesion and subsequent sperm agglutination and immobilization represent the most direct pathway of sperm-bacterial interactions. Furthermore, the release of bacterial toxins and leukocytic infiltration, associated with a massive outburst of reactive oxygen species, have been repeatedly associated with sperm dysfunction in bacteria-infested semen. This review serves as a summary of the present knowledge on bacteriospermia-associated male subfertility. Furthermore, we strived to outline the currently available methods for assessing bacterial profiles in semen and to outline the most promising strategies for the prevention and/or management of bacteriospermia in practice.

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

This study focused on the identification of bacterial profiles of semen in normozoospermic men and their possible involvement in changes to the sperm structural integrity and functional activity. Furthermore, we studied possible fluctuations of selected cytokines, oxidative markers, and antibacterial proteins as a result of bacterial presence in the ejaculate. Sperm motility was assessed with computer-assisted sperm analysis, while sperm apoptosis, necrosis and acrosome integrity were examined with fluorescent methods. Reactive oxygen species (ROS) generation was quantified via luminometry, sperm DNA fragmentation was evaluated using the TUNEL protocol and chromatin-dispersion test, while the JC-1 assay was applied to evaluate the mitochondrial membrane potential. Cytokine levels were quantified with the biochip assay, whilst selected antibacterial proteins were quantified using the ELISA method. The predominant species identified by the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were Staphylococcus hominis, Staphylococcus capitis and Micrococcus luteus. The results revealed that the sperm quality decreased proportionally to the increasing bacterial load and occurrence of conditionally pathogenic bacteria, including Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Antimicrobial susceptibility tests revealed a substantial resistance of randomly selected bacterial strains to ampicillin, vancomycin, tobramycin, and tetracycline. Furthermore, an increased bacterial quantity in semen was accompanied by elevated levels of pro-inflammatory cytokines, including interleukin-1, interleukin-2, interleukin-6, tumor necrosis factor alpha as well as ROS overproduction and lipid peroxidation of the sperm membranes. Our results suggest that semen quality may be notably affected by the bacterial quantity as well as quality. It seems that bacteriospermia may be associated with inflammatory processes, oxidative stress, sperm structural deterioration, and a subsequent risk for the development of subfertility, even in normozoospermic males.

Evaluation of Antifertility Effects of Sperm Immobilization Factor from Escherichia coli on Male Mice

Earlier in our laboratory, sperm immobilization factor (SIF) isolated from Escherichia coli has shown admirable contraceptive efficacy in female mice and thus generated interest in evaluating the same as a potential candidate for male contraception. Keeping this in mind, the present study was aimed at exploitation of SIF as contraceptive agent in male mouse model after intra testis administration. For this, Balb/c mice were administered with different concentrations (10, 50, 100, 200, or 400µg) of SIF and sacrificed on days 3,7,14,21,30,45,60, and 90. After sacrifice, results in terms of change in body weight, tissue somatic indices, seminal parameters, histology, hematological parameters, lipid peroxidation, testosterone level, and cytokines level were evaluated. The weight profile and TSI of all experimental groups showed no significant change. In case of seminal parameters, 400μg of SIF led to azoospermia up to 90 days and tissue histology also revealed hypo-spermatogenesis. No significant change was observed in haematological parameters after SIF (400µg) administration however, a significant decrease was observed in testosterone levels. The oxidative status and cytokines profile was also affected after SIF (400µg) inoculation. Thus, when administered via intra testis route, SIF can lead to azoospermia and poses to be a potent and safe antifertility agent.

Effects of common Gram-negative pathogens causing male genitourinary-tract infections on human sperm functions

Male genitourinary tract (MGT) bacterial infections are considered responsible for 15% of male infertility, but the mechanisms underlying decreased semen quality are poorly known. We evaluated in vitro the effect of strains of Gram-negative uropathogenic species (two E.coli strains, three K. pneumoniae strains, P. aeruginosa and E. cloacae) on motility, viability, mitochondrial oxidative status, DNA fragmentation and caspase activity of human spermatozoa. All strains, except P. aeruginosa, reduced significantly sperm motility, with variable effects. Sperm Immobilizing Factor (SIF) was largely responsible for deteriorating effects on sperm motility of E. coli strains since they were completely reverted by knockout of SIF coding recX gene. Sequence alignment for RecX showed the presence of high homologous sequences in K. pneumoniae and E. cloacae but not in P. aeruginosa. These results suggest that, in addition to E.coli, other common uropathogenic Gram-negative bacteria affect sperm motility through RecX products. In addition to sperm motility, the E. coli strain ATCC 35218 also affected sperm viability, and induced caspase activity, oxidative stress and DNA fragmentation suggesting an interspecies variability in the amount and/or type of the produced spermatotoxic factors. In general, our results highlight the need for a careful evaluation of semen infections in the diagnostic process of the infertile man.

The effect of lipopolysaccharide from uropathogenic Escherichia coli on the immune system, testis tissue, and spermatozoa of BALB/c mice

Objective

Uropathogenic Escherichia coli is known to cause urinary tract infections, and the endotoxin (lipopolysaccharide [LPS]) of this bacterium may cause deficiencies of sperm quality and morphology. In the present study, the effects of LPS on mouse sperm were studied, and the levels of interleukin (IL)-17A and possible changes in testis tissue were evaluated.

Methods

LPS of uropathogenic E. coli was extracted using the methanol-chloroform method, followed confirmation using sodium dodecyl sulfate-polyacrylamide electrophoresis. Purified LPS (100 µg/kg) or phosphate-buffered saline was injected intraperitoneally into BALB/c mice for 7 days consecutively in the test and control groups, mice were sacrificed on days 3, 7, and 42 after the first injection. Blood was tested for levels of IL-17A using the enzyme-linked immunosorbent assay method. Testis tissue and sperm were collected from each mouse and were studied according to standard protocols.

Results

The mean sperm count and motility significantly decreased (p=0.03) at 3, 7, and 42 days after the injections. The level of IL-17A in the test groups increased, but not significantly (p=0.8, p=0.11, and p=0.15, respectively). Microscopic studies showed no obvious changes in the morphology of the testis tissue; however, significant changes were observed in the cellular parenchyma on day 42.

Conclusion

LPS can stimulate the immune system to produce proinflammatory cytokines, resulting in an immune response in the testis and ultimately leading to deficiency in sperm parameters and testis tissue damage. In addition, the presence of LPS could significantly impair sperm parameters, as shown by the finding of decreased motility.

Role of Lactobacillus in Female Infertility Via Modulating Sperm Agglutination and Immobilization

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.

Fingerprint Biometric System Hygiene and the Risk of COVID-19 Transmission

Biometric systems use scanners to verify the identity of human beings by measuring the patterns of their behavioral or physiological characteristics. Some biometric systems are contactless and do not require direct touch to perform these measurements; others, such as fingerprint verification systems, require the user to make direct physical contact with the scanner for a specified duration for the biometric pattern of the user to be properly read and measured. This may increase the possibility of contamination with harmful microbial pathogens or of cross-contamination of food and water by subsequent users. Physical contact also increases the likelihood of inoculation of harmful microbial pathogens into the respiratory tract, thereby triggering infectious diseases. In this viewpoint, we establish the likelihood of infectious disease transmission through touch-based fingerprint biometric devices and discuss control measures to curb the spread of infectious diseases, including COVID-19.

Bacterial infection of the male reproductive system causing infertility

Bacterial infections play a disruptive and hidden role in male reproductive failure. Different kinds of bacteria are often able to interfere with reproductive function in both sexes and lead to infertility. In this study, to further evaluate the role of bacterial infections in male reproduction we provided an extensive overview of so far researches investigating the effects of bacterial infections on male fertility. We searched Medline, PubMed, Scopus and Google scholar databases to identify the potentially relevant studies on bacterial infections and their implications in male infertility. All the bacteria included in this article have negative effects on the male reproductive function; however, there is ample evidence to blame bacteria such as Escherichia coli, Chlamydia trachomatis, Ureaplasma, Mycoplasma and Staphylococcus aureus for reduced fertility and deterioration of sperm parameters. More studies are needed to clarify the molecular mechanisms by which different bacteria exert their detrimental effects on male reproductive system. Getting more insight into probable mechanisms, would significantly facilitate the production of new, advanced, and effective remedies in the future. In view of all evidence, we strongly suggest increasing awareness among people and considering screening programs for patients seeking fertility both to avoid transmission and to improve fertility outcomes among them.

Female immunity in response to sexually transmitted opportunistic bacteria in the common bedbug Cimex lectularius

Besides typical sexually transmitted microbes, even environmental, opportunistic microbes have been found in copulatory organs of insects and even humans. To date, only one study has experimentally investigated the sexual transmission of opportunistic microbes from male to female insects, whereas nothing is known about the transmission from females to males. Even if opportunistic microbes do not cause infection upon transmission, they might eventually become harmful if they multiply inside the female. While the immune system of females is often assumed to target sexually transmitted microbes, most studies ignore the role of mating-associated opportunistic microbes. Variation in immunity between populations has been linked to parasite or bacteria prevalence but no study has ever addressed between-population differences in immune responses to sexually transmitted opportunistic microbes. We here show that bacteria applied to the copulatory organs of common bedbugs, Cimex lectularius, are sexually transmitted to the opposite sex at a high rate, including the transmission from female to male. Bacterial growth in the female sperm-receiving organ was inhibited over the first hours after introduction, but after this initial inhibition bacterial numbers increased, suggesting a shift of investment from immune defence towards reproduction. However, 24 h after the injection of bacteria, male components, or saline as a control, the sperm-receiving organ showed lysozyme-like activity and inhibited the growth of Gram-negative and Gram-positive bacteria in vitro, potentially to mop up the remaining bacteria. Contrasting our prediction, neither bacterial growth nor immune responses differed between populations. Future studies should link transmission dynamics, immune responses and fitness effects in both sexes. Experimental manipulation of environmental bacteria could be used to investigate how transmission frequency and toxicity of sexually transmitted opportunistic microbes shapes bacteria clearance and immune responses across populations.

Mating changes the genital microbiome in both sexes of the common bedbug Cimex lectularius across populations

Many bacteria live on host surfaces, in cells and in specific organ systems. In comparison with gut microbiomes, the bacterial communities of reproductive organs (genital microbiomes) have received little attention. During mating, male and female genitalia interact and copulatory wounds occur, providing an entrance for sexually transmitted microbes. Besides being potentially harmful to the host, invading microbes might interact with resident genital microbes and affect immunity. Apart from the investigation of sexually transmitted symbionts, few studies have addressed how mating changes genital microbiomes. We dissected reproductive organs from virgin and mated common bedbugs, Cimex lectularius L., and sequenced their microbiomes to investigate composition and mating-induced changes. We show that mating changes the genital microbiomes, suggesting bacteria are sexually transmitted. Also, genital microbiomes varied between populations and the sexes. This provides evidence for local and sex-specific adaptation of bacteria and hosts, suggesting bacteria might play an important role in shaping the evolution of reproductive traits. Coadaptation of genital microbiomes and reproductive traits might further lead to reproductive isolation between populations, giving reproductive ecology an important role in speciation. Future studies should investigate the transmission dynamics between the sexes and populations to uncover potential reproductive barriers.

Contraceptive Sperm Agglutinating Proteins Identified in Staphylococcus warneri, Natural Microflora of an Infertile Woman

Staphylococcus warneri, isolated from the cervix of an adult female with unexplained infertility, was found to agglutinate human spermatozoa in vitro leading to their death. A genomic library of S. warneri was generated using pSMART-Escherichia coli vector-host system. Approximately 3500 transformants were screened and four showed sperm agglutinating activity. Sperm agglutinating proteins (SAPs) were partially purified from the positive transformants and were found to agglutinate sperms in vitro. Cloned ORFs in positive transformants were sequenced and ORF finder identified them as endonuclease, accessory secretory protein-Asp1, accessory secretory protein-Asp2 and signal transduction protein. Mannose was found to competitively inhibit sperm agglutination, indicating that SAPs in S. warneri bind to mannose in glycoprotein receptors on the surface of sperms for agglutination. This is the first report on identification of SAPs which may be responsible for unexplained infertility in women and may be used as contraceptive agents.

Escherichia coli recombinant sperm immobilizing factor RecX as a potential vaginal contraceptive

BACKGROUND

To control the overpopulation and unintended pregnancies, vaginal contraceptives have gained recent surge of interest because of its topical application with possible avoidance of systemic effects. However non-specific cytotoxicity associated with detergent-based synthetic vaginal contraceptive agents limits their use and generates considerable interest in the development of vaginal contraceptives of biological origin for controlling reproduction and ultimately growing population. In this study, we have cloned, over-expressed an Escherichia coli gene encoding a sperm immobilizing factor (SIF) that inhibits sperm motility for the development of vaginal contraceptive from a biological source i.e. E. coli. The contraceptive efficacy of the Escherichia coli recombinant sperm immobilizing factor (r-SIF) was also determined.

METHODS

Genomic DNA library of an E. coli strain isolated from semen sample of an infertile male was constructed for the identification and cloning of E. coli SIF coding gene. This gene was sub-cloned in pBADmycHisB for over-expression and the r-SIF was purified using Ni-NTA affinity chromatography. Effect of r-SIF on mouse sperm motility, viability and on morphology was evaluated. Binding of r-SIF to mouse sperm was demonstrated by fluorescent labeling. Contraceptive efficacy of r-SIF was checked in murine model.

RESULTS

Genomic library resulted in five hundred transformants; five clones were found positive for sperm immobilizing activity. The protein product of the insert DNA sequence in one of the transformants showed maximum sperm immobilizing activity. Sequence analysis of ORFs in the insert revealed homology to recX on both nucleotide and protein level. 40 μg of the purified r-SIF showed immediate spermicidal activity in vitro for mouse sperm. Scanning electron micrograph of the r-SIF treated sperm showed intense morphological damage to sperm. FITC labeled r-SIF showed highest fluorescence at the head region of the sperm. 5 μg of purified r-SIF exhibited a complete contraceptive effect in mouse model.

CONCLUSION

r-SIF could be seen as potential target to be developed as potent and safe vaginal contraceptive in future.

[Bacteriospermia: Effects on semen parameters]

OBJECTIVES

Bacteriospermia may result in male hypofertlity. Indeed, 60% of patients treated by Assisted Reproductive Techniques had a local infection or inflammation of genital tract. However, direct effects of bacteriospermia on semen parameters remain controversial. The aim of our work was to explore the effect of bacteriospermia on sperm parameters among patients consulting for hypofertility.

METHODS

A retrospective comparative study of two groups: a group of 70 patients with bacteriospermia (group 1) and a control group of 70 patients without bacteriospermia (group 2). For these groups, we studied the standard semen parameters (seminal volume and viscosity and spermatozoa count, initial and secondary mobility, vitality and morphology). Comparison of these parameters was made by the Chi² test and the Fisher test.

RESULTS

The mean age of our population was 40.4±6.7 years. There was no significant difference between ejaculate average volume in the 2 groups (group B: 2.78mL versus group A: 2.92mL with P=0.2). Similarly, for the viscosity no difference was noted (P=0,68). The altered parameters in the presence of bacteriospermia were mean concentration and sperm motility (P=0.001 and P=0.049 respectively). The prevalence of secondary asthenospermia was higher in the presence of bacterospermia (P=0.006). No statistically significant differences were observed for morphology and vitality of spermatozoa (P=0.276 and P=0.075 respectively). The leucospermia was associated with bacteriospermia in 10% patients. Ureaplasma urealyticum was the germ most found (45.7%) followed by Streptococcus and Staphylococcacae (20.3% for each), Gram negative rods accounted for 12.9%, while Corynebacterium spp was isolated only in 4,3% patients. U. urealyticum was associated with hypospermia in 33% of cases (P=0.031). Spermatozoa motility was significatively decreased not only in the presence of this bacteria (FT=0.002) but also when cultures were positive for Streptococcus (0.04) and Corynebacterium (P<0.001). Morphological abnormalities were also noticed with Streptococcus with index of teratozoospermia of 46% versus 19% in the 2nd group (P=0.046).

CONCLUSION

Bacteriospermia may impair sperm parameters. The treatment of this affection seems to improve sperm fertilizing potential. In addition, it could prevent contamination of culture media.

Antibacterial activity of male and female sperm-storage organs in ants

Bacteria can damage sperm and thus reduce the reproductive success of both males and females; selection should therefore favour the evolution of antimicrobial protection. Eusocial hymenopterans might be particularly affected by such bacterial infections because of their mating ecology. In both sexes, mating is restricted to a short window early in the adult stage; there are no further chances to mate later in life. Males die shortly after mating, but queens use the acquired sperm to fertilise their eggs for years, sometimes decades. The reproductive success of both sexes is, thus, ultimately sperm-limited, which maintains strong selection for high sperm viability before and after storage. We tested the antibacterial activity of the contents of the male and female sperm-storage organs - the accessory testes and the spermatheca, respectively. As our study species, we used the bacterium Escherichia coli and the garden ant Lasius niger, whose queens can live for several decades. Our results provide the first empirical evidence that male and female sperm-storage organs display different antibacterial activity. While the contents of the accessory testes actually enhanced bacterial growth, the contents of the spermatheca strongly inhibited it. Furthermore, mating appears to activate the general immune system in queens. However, antimicrobial activity in both the spermatheca and the control tissue (head-thorax homogenate) declined rapidly post-mating, consistent with a trade-off between immunity and reproduction. Overall, this study suggests that ejaculates undergo an immune 'flush' at the time of mating, allowing storage of sperm cells free of bacteria.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

A comparative study of the effects of Escherichia coli and Clostridium perfringens upon boar semen preserved in liquid storage

The present study compares the sperm quality of boar seminal doses artificially inoculated with Escherichia coli and Clostridium perfringens, and maintained in liquid storage at 15°C for a 9-day period. Seminal doses from 10 sexually mature Piétrain boars were diluted in a Beltsville Thawing Solution (BTS)-based extender and infected either with E. coli or C. perfringens, with bacterial loads ranging from 10¹ to 10⁷cfumL^-1. During storage, the changes in sperm quality were determined by assessing pH, sperm viability, sperm motiliy, sperm morphology, sperm agglutination degree, and sperm-bacteria interaction. The infection of seminal doses led to an alkalinization of the medium, which was of higher extend in doses infected with C. perfringens. The effect of contamination on sperm viability and motility relied on bacterial type and load. Therefore, while E. coli was more harmful than C. perfringens in bacterial loads ranging from 10¹ to 10⁶cfumL^-1, the detrimental impact of C. perfringens was more apparent than that of E. coli at a bacterial load of 10⁷cfumL^-1. Despite sperm morphology not being affected by either bacterial type or load, sperm agglutination and sperm-bacteria interaction were characteristic of doses infected with E. coli, and increased concomintantly with bacterial load and along storage period. In conclusion, the effects of infection by E. coli on sperm quality were dependent of both bacterial load and storage period, whereas the effects of C. perfringens were mainly dependent on the bacterial load, with a threshold at 10⁷cfumL^-1 from which the sperm quality of seminal doses was greatly impaired.

Bacteriospermia and Its Impact on Basic Semen Parameters among Infertile Men

Introduction. Semen analysis is considered as the surrogate marker for male fecundity while assessing infertile men. There are several reasons for altered semen quality and bacteriospermia could be one among them. Thereby the aim of our work is to study the semen culture and its impact on semen parameters among infertile men. Materials and Methods. Semen samples were collected from men attending infertility clinic. Semen parameters were analysed based on WHO guidelines. Also, samples were subjected to culture using standard bacteriological techniques. Results. A total of 85 samples were collected. A number of 47 (55.30%) had normal sperm count, 37 (43.50%) had oligozoospermia, and one (1.17%) had azoospermia. Teratozoospermia was the most common abnormality observed (81.17%) followed by asthenozoospermia (28.23%). The prevalence of bacteriospermia was 35.3%. Enterococcus faecalis (30%) was the most common organism isolated followed by Coagulase negative Staphylococcus (23.33%), Staphylococcus aureus (20%), and E. coli (10%). Other less frequently isolated organisms were Klebsiella pneumoniae (6.66%), Proteus sp. (6.66%), and Citrobacter sp. (3.33%). Conclusion. The presence of asymptomatic bacteriospermia did not correlate with abnormal semen parameters.

Bacteriospermia and Its Impact on Basic Semen Parameters among Infertile Men

Introduction. Semen analysis is considered as the surrogate marker for male fecundity while assessing infertile men. There are several reasons for altered semen quality and bacteriospermia could be one among them. Thereby the aim of our work is to study the semen culture and its impact on semen parameters among infertile men. Materials and Methods. Semen samples were collected from men attending infertility clinic. Semen parameters were analysed based on WHO guidelines. Also, samples were subjected to culture using standard bacteriological techniques. Results. A total of 85 samples were collected. A number of 47 (55.30%) had normal sperm count, 37 (43.50%) had oligozoospermia, and one (1.17%) had azoospermia. Teratozoospermia was the most common abnormality observed (81.17%) followed by asthenozoospermia (28.23%). The prevalence of bacteriospermia was 35.3%. Enterococcus faecalis (30%) was the most common organism isolated followed by Coagulase negative Staphylococcus (23.33%), Staphylococcus aureus (20%), and E. coli (10%). Other less frequently isolated organisms were Klebsiella pneumoniae (6.66%), Proteus sp. (6.66%), and Citrobacter sp. (3.33%). Conclusion. The presence of asymptomatic bacteriospermia did not correlate with abnormal semen parameters.

Presence of aerobic micro-organisms and their influence on basic semen parameters in infertile men

Urogenital tract infections in males are one of the significant etiological factors in infertility. In this prospective study, 72 patients with abnormal semen parameters or any other symptoms of urogenital tract infection were examined. Semen analysis according to the WHO 2010 manual was performed together with microbial assessment: aerobic bacteria culture, Chlamydia antigen test, Candida culture, Ureaplasma and Mycoplasma-specific culture. In total, 69.4% of semen samples were positive for at least one micro-organism. Ureaplasma sp. was the most common micro-organism found in 33% of semen samples of infertile patients with suspected male genital tract infection. The 2nd most common micro-organisms were Enterococcus faecalis (12.5%) and Escherichia coli (12.5%), followed by Staphylococcus aureus (7%), Chlamydia trachomatis (7%) and Candida sp. (5.6%). Generally, bacteria were sensitive to at least one of the antibiotics tested. No statistically significant relationship was observed between the presence of aerobic micro-organisms in semen and basic semen parameters: volume, pH, concentration, total count, motility, vitality and morphology.

Another reason for impeccable oral hygiene: oral hygiene-sperm count link

OBJECTIVES

1. To investigate the relationship between periodontitis and infertility. 2. To evaluate the importance of oral hygiene to general health.

MATERIALS AND METHODS

Eighty-six men requiring seminal fluid analysis as part of an on-going investigation for infertility in their spouses were serially recruited into the study. Basic dental and periodontal examination were performed. Each participant was also screened for periodontitis using a lateral flow immunoassay kit which detected levels of active membrane metalloproteinase-8. RESULTS were read-off as a color change. Due to some incomplete entries, only 76 participants were involved in the final data analysis.

RESULTS

There were 55 subjects with subnormal counts (of which ten were found to be azoospermic, 41 oligospermic) and 25 normospermic controls. A positive association was found between periodontitis and subnormal sperm count in only one age group but statistically significant association was found between poor oral hygiene and subnormal sperm count across all age groups.

CONCLUSION

For the first time, there appears to be a significant association between poor oral and subnormal sperm count. There also appears to an association between chronic periodontitis and subnormal sperm count. These relationships warrant further investigation.

PRINCIPAL FINDINGS

There appears to be a link between poor oral hygiene and low sperm count.

Seminal bacterial contaminations: Probable factor in unexplained recurrent pregnancy loss

BACKGROUND

It is estimated that about 50% of causes of recurrent pregnancy loss (RPL) cases remain unknown. Sperm factors are suggested to have probable role in cases with RPL.

OBJECTIVE

The goal was to determine the possible relationship between semen bacterial contaminations with unexplained RPL. Also, the correlation between number of bacterial colony and sperm chromatin condensation was examined.

MATERIALS AND METHODS

This study consisted of 30 fertile men (group A) and 30 infertile (group B) men with unknown RPL. Semen collection and analysis were done according to WHO manuals. Sperm count and motility were evaluated by Makler chamber. Eosin-Nigrosin and Papanicolaou staining methods were applied for viability and morphology assessment, respectively. The semen samples from both groups were cultured for aerobic bacteria. Aniline blue (AB) and toluidine blue (TB) staining methods were applied for evaluating sperm chromatin condensation.

RESULTS

The numbers of colonies were significantly higher in group B when compared to group A. Also, S. aureus and E. coli contaminations showed significant differences between two groups. Both AB+ and TB+ sperm cells showed significant increase in group B compared to group A. There was a significant negative correlation between colony number and progressive motility (p=0.01), and sperm viability (p=0.007). In addition, positive correlations were found between colony number and AB(+) (p=0.001) and TB+ (p=0.004) as well.

CONCLUSION

Bacterial contaminations in semen of men from RPL couples had significantly higher levels when compared to fertile controls. Presence of microorganisms in semen may be correlated with irregular sperm parameters and quality.

Male accessory gland infection and sperm parameters (review)

Male accessory gland infection (MAGI) has been identified among those diagnostic categories which have a negative impact on the reproductive function and fertility in males (Rowe et al., World Health Organization Manual for the Standardised Investigation and Diagnosis of the Infertile Couple, Cambridge University Press, Cambridge, 1993). MAGI is a hypernym which groups the following different clinical categories: prostatitis, prostate-vesiculitis and prostate-vesiculo-epididymitis. Some of the characteristics they share are: common diseases, mainly have a chronic course, rarely cause obstruction of the seminal pathways, can have an unpredictable intracanicular spread to one or more sexual accessory glands of the reproductive tract, as well as to one or both sides. In this review, we show that all components involving the inflammatory response (from the agents which first trigger it to each component of the inflammatory response dynamic) can deteriorate conventional and/or non-conventional sperm parameters arising from one or more of the following mechanisms: altered secretory function of the epididymis, seminal vesicles, and prostate which reduce the antioxidant properties or scavenging role of the seminal plasma; deterioration of spermatogenesis; and (unilateral or bilateral) organic or functional sub-obstruction of the seminal tract.

Sexual ornamentation reflects antibacterial activity of ejaculates in mallards

Bacteria present in ejaculates can impair sperm function and reduce male reproductive success. Thus, selection should favour the evolution of antimicrobial defences to limit the detrimental effects of sperm-associated bacteria. Additionally, current hypotheses suggest that ornamental traits may signal information about the infection status of an individual or the ability of an individual to resist bacterial-induced sperm damage. However, despite the evolutionary implications of ejaculate antimicrobials, and the putative importance of pathogens for the evolution of male ornamentation, tests of these hypotheses are lacking. We examined the antibacterial activity of semen from mallard ducks (Anas platyrhynchos) and tested whether the bactericidal capacity of semen was associated with bill coloration, a sexually selected trait. We show that mallard semen exhibits significant antibacterial activity, as measured by the in vitro capacity to kill Escherichia coli and Staphylococcus aureus. Furthermore, we demonstrate that males with more colourful bills have semen with superior bacterial-killing ability. These results suggest that females could use male phenotypic traits to avoid sexually transmitted pathogens and acquire partners whose sperm suffer less bacteria-induced damage.