The Vaginal Microbiome Changes During Various Fertility Treatments

This study aimed to investigate the influence of hormonal treatment on the vaginal microbiome during fertility treatments. Bacterial vaginosis (BV) could affect fecundity, particularly in the in vitro fertilization (IVF) population, where negative effects on pregnancy outcomes have been reported. It is hypothesized that the hormone treatment during fertility treatments could influence the abundance of Lactobacilli, with negative effects on the pregnancy results. A total of 53 couples attending a fertility clinic in the Netherlands between July 2019 and August 2022 were included in this prospective cohort study. Vaginal samples were collected at start of treatment, oocyte retrieval or insemination from subjects undergoing intra uterine insemination (IUI) with mild ovarian stimulation, and IVF or intra cytoplasmatic sperm injection (ICSI) with controlled ovarian hyperstimulation. AmpliSens® Florocenosis/Bacterial vaginosis-FRT qPCR and 16S rRNA gene-based amplicon sequencing were performed on all samples. In total, 140 swabs were analyzed, with a median of two swabs per person. 33 (24%) tested qPCR BV positive. Lactobacilli percentage decreased during fertility treatments, leading to changes in the vaginal microbiome. Shannon diversity index was not significantly different. Of the total of 53 persons, nine switched from qPCR BV negative to positive during treatment. The persons switching to qPCR BV positive had already a (not significant) higher Shannon diversity index at start of treatment. If the vaginal microbiome of persons deteriorates during fertility treatments, timing of following treatments, lifestyle modifications, or a freeze all strategy could be of possible benefit.

Epidemiology of genital infections caused by Mycoplasma hominis, M. genitalium and Ureaplasma urealyticum in Iran; a systematic review and meta-analysis study (2000-2019)

BACKGROUND

Although many species of mycoplasmas regard as normal flora, but some species causes serious genital disease. In Iran several epidemiological studies have documented the prevalence of Mycoplasma hominis, M. genitalium and Ureaplasma urealyticum in genital disorders. This meta-analysis is going to represent the prevalence of M. hominis, M. genitalium and U. urealyticum among Iranian couples and the correlation between mycoplasmas infection and infertility.

METHODS

We search online databases from January 2000 to June 2019. We used following MeSH keywords (Prevalence, M. hominis, M. genitalium, U. urealyticum, male, female, fertility, Infertility, genitourinary tract infection and Iran) with all possible combinations with "OR" and "AND". Finally, forty-four articles from 2670 were chosen for data extraction and analysis by software using STATA version 14.0.

RESULTS

This meta-analysis revealed that the prevalence of U. urealyticum was 17.53% in Iran and the prevalence of M. genitalium and M. hominis were 11.33 and 9.68% respectively. The rate of M. genitalium, M. hominis and U. urealyticum infection in women with symptoms of genitourinary tract infection was higher than men with genitourinary tract infection (6.46% vs 5.4, 7.67% vs 5.88 and 21.04% vs 12.13%, respectively). As expected, the prevalence of M. genitalium, U. urealyticum and M. hominis among infertile women (12.73, 19.58 and 10.81%) were higher than fertile women (3%, 10. 85% and 4. 35%). Similarly, the prevalence of M. hominis and U. urealyticum among infertile men (14 and 21.18%) were higher than fertile men (4 and 3%). Based on this analysis, the rate of U. urealyticum was higher than M. genitalium and M. hominis among infertile men and women compared to the fertile group. The prevalence rate of M. genitalium, M. hominis and U. urealyticum in central provinces is higher than other parts of Iran.

CONCLUSIONS

This meta-analysis reemphasizes a significant relationship between the infertility rate and U. urealyticum, M. genitalium and M. hominis infections. Our finding help to plan the prevalence map of M. hominis, M. genitalium and U. urealyticum in Iran but further studies are needed to suggest routine screening of the pathogens.

Diversity of endocervical microbiota associated with genital Chlamydia trachomatis infection and infertility among women visiting obstetrics and gynecology clinics in Malaysia

The cervical microbiota constitutes an important protective barrier against the invasion of pathogenic microorganisms. A disruption of microbiota within the cervical milieu has been suggested to be a driving factor of sexually transmitted infections. These include Chlamydia trachomatis which frequently causes serious reproductive sequelae such as infertility in women. In this study, we profiled the cervical microbial composition of a population of 70 reproductive-age Malaysian women; among which 40 (57.1%) were diagnosed with genital C. trachomatis infection, and 30 (42.8%) without C. trachomatis infection. Our findings showed a distinct compositional difference between the cervical microbiota of C. trachomatis-infected subjects and subjects without C. trachomatis infection. Specifically, significant elevations of mostly strict and facultative anaerobes such as Streptococcus, Megasphaera, Prevotella, and Veillonella in the cervical microbiota of C. trachomatis-positive women were detected. The results from the current study highlights an interaction of C. trachomatis with the environmental microbiome in the endocervical region.

[Chlamydia trachomatis infection's eradication : a daily goal]

Chlamydia trachomatis (CT) infection is the most frequent notifiable sexually transmitted infection (STI) in Switzerland. The infection is most frequently observed in 15 to 24 year-old-women and in 25 to 34 year-old-men. 50-75 % of the Chlamydia trachomatis carriage are asymptomatic, making the infection difficult to diagnose and increasing the untreated specimen, leading to complications like infertility, ectopic pregnancy or pelvic inflammatory disease. Despite having a sexual prevention at school, the youths seem to have a lack of knowledge about CT, her transmission and her complications. We performed a survey, which showed that 60.5 % of the participants ignored that this bacteria is mostly asymptomatic. We also found that 11 % of the participants believed that there is no possible relapse of the infection. The prevention must be strengthened, mostly because there is no program in Switzerland, letting every physician to his own beliefs. The medical consultation is an ideal opportunity for this prevention and the youths shared their wish to discuss more about it with health professionals.

Colonization of mouse vagina with Pseudomonas aeruginosa: A plausible explanation for infertility

Little attention has been paid to the influence of asymptomatic colonizers of genital tract on female infertility. Albeit, a variety of uropathogens have been known to negatively alter sperm parameters in vitro, but their impact on female fertility outcome under in vivo conditions is not clearly established. Therefore, the present study was intended to investigate the effect of Pseudomonas aeruginosa on sperm parameters and to identify its role in female infertility. The strain of P. aeruginosa was found to reduce sperm motility, viability and sperm Mg⁺⁺ATPase activity. It could also lead to premature acrosomal loss and induce morphological defect in spermatozoa. For fertility studies, female mice administered intravaginally with 10⁴, 10⁶, 10⁸ cfu of P. aeruginosa for 10 consecutive days, were allowed to mate with proven breeder male on day 12. The results showed that group of mice receiving P. aeruginosa were rendered infertile whereas group receiving PBS showed abdominal distension, string of pearls and finally delivered pups at the end of gestation period. Further, no other clinical manifestation could be observed apparently, histologically or immunologically. Thus, it can be concluded that infertility in mice might be attributed to asymptomatic colonization of genital tract with sperm immobilizing P. aeruginosa.

The Association between Infertility and Helicobacter pylori Infection: a Meta-Analysis of Case-control Studies

BACKGROUND

Helicobacter pylori (H. pylori) is increasingly associated with extra-digestive diseases. Infertility is a common condition, with an incidence of 10 to 15% of couples. Studies examining the association of H. pylori infection and infertility have reported conflicting results. This meta-analysis aimed to investigate the association between H. pylori infection and infertility.

METHODS

Studies of H. pylori infection and infertility were identified in PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure. We performed a meta-analysis of all case-control studies.

RESULTS

Seven studies that analyzed the relationship between H. pylori infection and infertility, with a combined study population of 1,902 patients, were included in the meta-analysis (n = 626 for patients; n = 1,276 for controls). In the infertility group, 344 (54.9%) patients were H. pylori-positive, and 495 (38.8%) were H. pylori-positive in the control group. Our result suggested that H. pylori infection was associated significantly with infertility (OR = 1.45, 95% CI: 1.197 - 2.160; I2 = 36.5%, Z = 3.15, p = 0.002). Begg's and Egger's funnel plot showed no publication bias (p = 0.807).

CONCLUSIONS

Our meta-analysis identified a possible association between H. pylori infection and infertility.

Racial/Ethnic Disparities in the Lifetime Risk of Chlamydia trachomatis Diagnosis and Adverse Reproductive Health Outcomes Among Women in King County, Washington

Background

Chlamydia trachomatis is the most common reportable infection in the United States and can cause pelvic inflammatory disease (PID) and tubal factor infertility (TFI).

Methods

We created life tables to estimate the "lifetime" risk of chlamydia diagnosis among women aged 15-34 years in King County, Washington, between 1992 and 2014. We estimated the lifetime risk of chlamydia-associated PID and TFI incorporating published estimates of the risk of sequelae.

Results

There were 51464 first chlamydia diagnoses in 1992-2014. For women born between 1980 and 1984, the lifetime risk of chlamydia diagnosis was 19.8% overall and 14.0% for non-Hispanic white, 64.9% for non-Hispanic black, and 32.6% for Hispanic women. The cumulative risk of chlamydia by age 24 increased overall from 13.9% to 17.3% among women born between 1975 and 1994 but declined among non-Hispanic black women, among whom risk by age 24 declined from 57.3% among women born between 1980 and 1984 to 38.6% among women born between 1990 and 1994. The lifetime risk of chlamydia-associated PID among women born between 1980 and 1984 ranged from 0.33% to 1.14%. Among non-Hispanic white, non-Hispanic black, and Hispanic women, the lifetime risk of chlamydia-associated TFI was 0.04%, 0.20%, and 0.10%, respectively.

Conclusions

Over 60% of non-Hispanic black women had at least 1 chlamydia diagnosis by age 34 in the birth cohorts most affected, a risk almost 5 times that in non-Hispanic whites. An estimated 1 in 500 non-Hispanic black women develops chlamydia-associated TFI. More effective control measures are needed.

Whole-Exome Sequencing to Identify Novel Biological Pathways Associated With Infertility After Pelvic Inflammatory Disease

BACKGROUND

Ideal management of sexually transmitted infections (STI) may require risk markers for pathology or vaccine development. Previously, we identified common genetic variants associated with chlamydial pelvic inflammatory disease (PID) and reduced fecundity. As this explains only a proportion of the long-term morbidity risk, we used whole-exome sequencing to identify biological pathways that may be associated with STI-related infertility.

METHODS

We obtained stored DNA from 43 non-Hispanic black women with PID from the PID Evaluation and Clinical Health Study. Infertility was assessed at a mean of 84 months. Principal component analysis revealed no population stratification. Potential covariates did not significantly differ between groups. Sequencing kernel association test was used to examine associations between aggregates of variants on a single gene and infertility. The results from the sequencing kernel association test were used to choose "focus genes" (P < 0.01; n = 150) for subsequent Ingenuity Pathway Analysis to identify "gene sets" that are enriched in biologically relevant pathways.

RESULTS

Pathway analysis revealed that focus genes were enriched in canonical pathways including, IL-1 signaling, P2Y purinergic receptor signaling, and bone morphogenic protein signaling.

CONCLUSIONS

Focus genes were enriched in pathways that impact innate and adaptive immunity, protein kinase A activity, cellular growth, and DNA repair. These may alter host resistance or immunopathology after infection. Targeted sequencing of biological pathways identified in this study may provide insight into STI-related infertility.

Bacterial agents as a cause of infertility in humans

Infertility is a problem affecting almost 15% of couples. There are many causes for this condition, among which urogenital bacterial infections seem to play an important role. Many studies have explained the mechanisms by which bacteria cause infertility both in men and women. Therefore we undertook this study to evaluate the presence of genito-urinary infections in infertile couples who sought counselling to investigate their condition. Microbiological analysis was performed on semen and vaginal/cervical samples of both partners of each couple. The percentage of individuals affected by a urogenital bacterial infection was between 14 and 20%. More significantly, most of the species isolated both in men and women have been described in the literature as potential causes of infertility.

[Findings in uteri and ovaries from Eringer cows slaughtered due to fertility problems]

Eringer cows are often slaughtered due to fertility problems which result from inflammatory and degenerative changes of the uterus or hormonal imbalances. Twenty-one genital tracts from Eringer cows suffering from fertility problems were collected in the abattoir. The purpose of the study was the macroscopic evaluation of the ovaries and the uterus followed by a histological and microbiological analysis of the uterus. Data from inseminations and calvings were provided by the Eringer breeding association and through the internet portal www.agate.ch. Median age of the cows was 6.9 years, number of calves per cow was 2.5 and median period between last calving and slaughter was 1.5 years. In 13 from 21 of the urogenital tracts examined, macroscopic abnormalities of the ovaries and/or histologic or microbiologic findings in the uterus could explain fertility-associated slaughter.

[SOME DIAGNOSTIC ASPECTS OF CHLAMYDIA TRACHOMATIS UROGENITAL INFECTIONS]

The following tests were used to make the diagnosis of Chlamydia Trachomatis: Ensime Immunoassay (EIA), Enzyme-Linked FluorescentAssay (ELFA), Polymerase Chain Reaction DNA amplification for Chlamydia Trachomatis, Neisseria Gonorrhoeae, Mycoplasma Genitalium and Ureaplasma Urealyticum. The subject of this study were 486 outpatients between the ages of 17 and 62, diagnosed with urethritis, epidydimitis, prostatitis, cervicitis, endocervicitis, pelvic inflammatory disease and sterility. Comparison PCR and EIA showed statistically significant difference between the positive results obtained by the two methods (p<0.001). Comparing PCR and ELFA on the other hand, did not show any statistically significant difference (p>0.1). EIA is the method that gives a higher percentage of nonspecific positive reactions, while the results obtained with ELFA are much closer to the ones obtained by PCR. According to contemporary evidence based medicine, the development of unified standart methods for diagnosis and evaluation is of vital importance, not only for the patient and the treating physician but also concerns for the healthcare system, the general public and the pharmaceutical companies as well.

Factors in Early-Life Programming of Reproductive Fitness

Fertility rates have been declining worldwide, with a growing number of young women suffering from infertility. Infectious and inflammatory diseases are important causes of infertility, and recent evidence points to the critical role of the early-life microbial environment in developmental programming of adult reproductive fitness. Our laboratory and others have demonstrated that acute exposure to an immunological challenge early in life has a profound and prolonged impact on male and female reproductive development. This review presents evidence that perinatal exposure to immunological challenge by a bacterial endotoxin, lipopolysaccharide, acts at all levels of the hypothalamic-pituitary-gonadal axis, resulting in long-lasting changes in reproductive function, suggesting that disposition to infertility may begin early in life.

[Research progress in pathogenicity of Ureaplasma urealyticum]

Ureaplasma urealyticum (UU) is closely related to human diseases including non-gonococcal urethritis (NGU), infertility, premature membranes and neonatal bronchopulmonary dysplasia. Researches on the pathogenicity of UU have become a hot topic in recent years, and suggest that many potential pathogenicity genes or putative pathogenicity islands are involved in its virulence. Moreover, the biovar and serum types of UU, the infection concentration and the state of the host immune system are also important to determine whether UU can cause human disease or not. In this article the recent progress of researches in the pathogenicity of UU is reviewed.

Recent acquisitions in the medical treatment of infertility caused by Chlamydia Trachomatis

The infertility defined as the incapacity of the people to conceive a child in a given period, usually of 1-2 years of sexually unprotected relations, represents a major dysfunction of the genital apparatus. Its frequency is estimated at 10-15% of the couples at the reproductive age. The incidence of sterility is high, a couple out of 10 being sterile. The conjugal sterility is a phenomenon representative for the couple; the woman is responsible for it only in 35-40% of the cases, in 40% of the cases, the male factor is involved. In 20% of the cases, mixed factors are met, both feminine and masculine, and in 5-10% of the cases, the causes cannot be detected. From the multitude of causes of infertility, the infectious factor plays an important role, the Chlamydia infections being lately blamed in the etiology of sterility. The infections due to Chlamydia Trachomatis (CT) represent the most frequent sexually transmitted diseases, which, most of the times lead to sterility. Taking into account the widespread of this bacterium in the sexually active population, the effective treatment of the CT infection is very important. We have selected 200 cases with PID genital infection in the study. All the selected patients had at least 2, 3 and more than 3 inflammation recurrence episodes, this way being considered cases with medium and severe forms of disease. All these selected patients had at least 2, 3 and more than 3 episodes of inflammation recurrence, this way being considered medium and severe disease cases. In conclusion, there is a high clinical efficiency of the azithromycin treatment in PID case.

[Bacterial infection as a cause of infertility in humans]

Microorganisms which are present in the human urogenital tract may be involved in the development of inflammatory changes negatively affecting the genitals in both men and women. Pathological conditions due to inflammatory alterations may result in complete loss of fertility. Infections of the urogenital tract are responsible for 15% of all cases of infertility in couples. Negative impact on the human reproduction is mainly caused by direct damage to the genital tract mucosa by metabolic products of microorganisms or by induction of pro-inflammatory responses of the body. Another mechanism is indirect impact of microorganisms on the genital function. Moreover, the effect of bacteria on spermatogenesis and semen quality is important in men. Infections mainly caused by Chlamydia trachomatis or Neisseria gonorrhoeae represent the greatest risk in terms of permanent consequences for human reproduction. As for other sexually transmitted disorders, such as infections caused by Gardnerella vaginalis, urogenital mycoplasmas or ureaplasmas, the link between infection and infertility has been intensively researched.

Coxiella burnetii associated reproductive disorders in domestic animals--a critical review

The bacterium Coxiella burnetii has been detected in the fetal membranes, birth fluids and vaginal mucus, as well as in the milk and other excretions of several domestic mammals. The finding of C. burnetii in association with abortion, parturition and in the postpartum period has led to the hypothesis that C. burnetii causes a range of reproductive diseases. This review critically evaluates the scientific basis for this hypothesis in domestic mammals.The review demonstrates a solid evidence for the association between C. burnetii infection and sporadic cases of abortion, premature delivery, stillbirth and weak offspring in cattle, sheep and goats. C. burnetii induced in-herd epidemics of this complete expression of reproductive failure have been reported for sheep and goats, but not for cattle. The single entities occur only as part of the complex and not as single events such as generally increased stillbirth rate. Studies show that C. burnetii initially infects the placenta and that subsequent spread to the fetus may occur either haematogenous or by the amniotic-oral route. The consequences for the equine, porcine, canine and feline conceptus remains to the elucidated but that infection of the conceptus may occur is documented for most species. There is no solid evidence to support a hypothesis of C. burnetii causing disorders such as subfertility, endometritis/metritis, or retained fetal membranes in any kind of domestic animal species.There is a strong need to validate non-pathology based methods such as polymerase chain reaction for their use in diagnostic and research in relation to establishing C. burnetii as the cause of abortion and to adapt an appropriate study design and include adequate control animals when linking epidemiological findings to C. burnetii or when evaluating effects of vaccination in production herds.

[Identification and analysis of a putative pathogenicity island Uu146-Uu170 in Ureaplasma urealyticum collected from sterile patients]

OBJECTIVE

To identify and analyze a putative pathogenicity island (PAI) Uu146-Uu170 of Ureaplasma urealyticum (Uu) and explore the relationship between PAI and infertility.

METHODS

Fifty-one Uu isolates were collected from healthy females, 57 isolates from sterile females with fallopian tube disease, 42 isolates from healthy males and 38 isolates from sterile males. Biovar-typing was performed based on the gene of multiple-banded antigen (MBA). The distribution of PAI was analyzed by PCR. The association of clinical phenotype with biovar type and PAI distribution was calculated by Fisher's exact test.

RESULTS

In female healthy group and female disease group, biovar type 1 account for 68.6% (35/51) and 73.7% (42/57), whereas the positive rate of PAI were 15.7% (8/51) and 12.3% (7/57) in the two groups, both difference were not statistically significant. In male healthy group and male disease group, biovar type 1 account for 71.4% (30/42) and 65.8% (25/38), whereas the positive rate of PAI were 21.4% (9/42) and 18.4% (7/38) in the two groups, both difference were not statistically significant. The positive rate of PAI in biovar type 2 was significantly higher than that in biovar type 1 in the fallopian tube disease and male infertility groups (5/15 vs 2/42, 5/13 vs 2/25, both P < 0.05) whereas no significant difference was found between two biovar types in normal groups (both P > 0.05).

CONCLUSIONS

There is insufficient evidence that Uu with presence of PAI is more pathogenic to cause infertility. The Uu strain of biovar type 2 with PAI Uu146-Uu170 may be associated with infertility.

The prevalence of bovine venereal campylobacteriosis in cattle herds in the Lake Chad basin of Nigeria

The prevalence of bovine venereal campylobacteriosis (BVC) was investigated in the Lake Chad basin of Nigeria. Preputial washings and cervico-vaginal mucus samples were obtained from 270 cattle presenting a history of abortion and lowered fertility, kept in traditional and institutional farms. All the samples investigated were cultured using standard bacteriological technique. Campylobacter fetus was isolated from six bulls and four cows. In all cattle sampled, the isolation rates were 2.2% for C. fetus subsp. venerealis and 1.5% for C. fetus subsp. fetus; the herd and within-herd prevalence rates for C. fetus were 22.2% and 3.4%, respectively, while the overall active infectivity rate was 3.7%. BVC probably contributes to lowered fertility and abortions found in cattle in the Lake Chad basin of Nigeria, associated more with C. fetus subsp. venerealis than C. fetus subsp. fetus.

[Role of heat shock proteins (Hsp) in human and mammalian fertilization and pregnancy. Part II]

Hsp expression is fundamental during gametogenesis in mammals and human. Different Hsps are required for each step of spermatogenesis and ovogenesis in order to provide the normal course of the transformation and differentiation processes. Hsp are proved to be among the first proteins found in the zygote. The Hsp synthesis is restored as soon as transcription is regained in the blastocyst. Hsp serve as modulating signals for the immune system, either for immunosuppression or immunostimulation. Certain Hsp members are immunodominant antigens for a number of microbial pathogens, e.g. Chlamydia trachomatis. A chlamydial infection leads to antichlamydial antibodies formation, which cross-react with self Hsp molecules and thus fertilization, implantation and pregnancy are disrupted, as well as there is worse reproductive perspective and lower success results from the assisted reproduction techniques. Further studies are needed to study the Hsp role at different stages of normal human pregnancy, as well as the immune response to Hsp as a factor for infertility.

A re-examination of Wolbachia-induced cytoplasmic incompatibility in California Drosophila simulans

BACKGROUND

In California Drosophila simulans, the maternally inherited Riverside strain Wolbachia infection (wRi) provides a paradigm for rapid spread of Wolbachia in nature and rapid evolutionary change. wRi induces cytoplasmic incompatibility (CI), where crosses between infected males and uninfected females produce reduced egg-hatch. The three parameters governing wRi infection-frequency dynamics quantify: the fidelity of maternal transmission, the level of cytoplasmic incompatibility, and the relative fecundity of infected females. We last estimated these parameters in nature in 1993. Here we provide new estimates, under both field and laboratory conditions. Five years ago, we found that wRi had apparently evolved over 15 years to enhance the fecundity of infected females; here we examine whether CI intensity has also evolved.

METHODOLOGY/PRINCIPAL FINDINGS

New estimates using wild-caught flies indicate that the three key parameters have remained relatively stable since the early 1990s. As predicted by our three-parameter model using field-estimated parameter values, population infection frequencies remain about 93%. Despite this relative stability, laboratory data based on reciprocal crosses and introgression suggest that wRi may have evolved to produce less intense CI (i.e., higher egg hatch from incompatible crosses). In contrast, we find no evidence that D. simulans has evolved to lower the susceptibility of uninfected females to CI.

CONCLUSIONS/SIGNIFICANCE

Evolution of wRi that reduces CI is consistent with counterintuitive theoretical predictions that within-population selection on CI-causing Wolbachia does not act to increase CI. Within taxa, CI is likely to evolve mainly via pleiotropic effects associated with the primary targets of selection on Wolbachia, i.e., host fecundity and transmission fidelity. Despite continuous, strong selection, D. simulans has not evolved appreciably to suppress CI. Our data demonstrate a lack of standing genetic variation for CI resistance in the host.

[Bacteriospermia and the production of reactive oxygen species in the semen of males from infertile couples]

OBJECTIVE

To estimate the incidence of bacteriospermia, the representation of specific micro-organisms and the generation of reactive oxygen species (ROS) in the semen of males from infertile couples in comparison with the semen of fertile volunteers.

MATERIAL AND METHODS

Males from infertile couples were divided according to WHO criteria of their spermiogram results into those with normospermia (Group A, n = 65) and those with semen abnormalities (Group B, n = 116). The control group consisted of 44 fertile volunteers (Group C, n = 44). Aerobic culture was performed to ascertain the genus and species of the present microorganisms. ROS production was estimated by the chemiluminescence method. Statistical analysis was performed using the Mann-Whitney test.

RESULTS

The incidence of positive cultures in the semen between Groups A, B and C (69 %, 74 % and 66 %, respectively) did not differ significantly, with Staphylococcus and Streptococcus species being most frequently identified. A significant difference was found only between the occurrence of microorganism Escherichia coli in the groups A, B and C (11.1 %, 9.3 % and 3.2 %). There were no statistically significant differences between ROS production in semen with positive or negative culture in any of the studied groups.

CONCLUSIONS

In all the studied groups, the incidence of bacteriospermia as well as ROS production in the semen were similar. Staphylococcus and Streptococcus species were found in all groups. A significantly higher frequency of Escherichia coli in the semen samples of males from infertile couples in comparison with those from fertile volunteers was observed. No differences in ROS production in semen samples with positive and negative culture results were found in any of the studied groups.

[Abortions, fertility problems and mastitis on a cattle farm and a sick farmer: a zoonosis? Infection with Staphylococcus aureus phagetype T543]

On a dairy farm the herdsman got a pustular dermatitis and in the herd in a year several abortions occurred, the somatic cell count of the bulk milk increased and the fertility results decreased. The cause appeared to be an infection in both the herdsman and the herd with Staphylococcus aureus type T543.

Cost effectiveness of home based population screening for Chlamydia trachomatis in the UK: economic evaluation of chlamydia screening studies (ClaSS) project

OBJECTIVE

To investigate the cost effectiveness of screening for Chlamydia trachomatis compared with a policy of no organised screening in the United Kingdom.

DESIGN

Economic evaluation using a transmission dynamic mathematical model.

SETTING

Central and southwest England.

PARTICIPANTS

Hypothetical population of 50,000 men and women, in which all those aged 16-24 years were invited to be screened each year.

MAIN OUTCOME MEASURES

Cost effectiveness based on major outcomes averted, defined as pelvic inflammatory disease, ectopic pregnancy, infertility, or neonatal complications.

RESULTS

The incremental cost per major outcome averted for a programme of screening women only (assuming eight years of screening) was 22,300 pounds (33,000 euros; $45,000) compared with no organised screening. For a programme screening both men and women, the incremental cost effectiveness ratio was approximately 28,900 pounds. Pelvic inflammatory disease leading to hospital admission was the most frequently averted major outcome. The model was highly sensitive to the incidence of major outcomes and to uptake of screening. When both were increased the cost effectiveness ratio fell to 6200 pound per major outcome averted for screening women only.

CONCLUSIONS

Proactive register based screening for chlamydia is not cost effective if the uptake of screening and incidence of complications are based on contemporary empirical studies, which show lower rates than commonly assumed. These data are relevant to discussions about the cost effectiveness of the opportunistic model of chlamydia screening being introduced in England.

From parasite to mutualist: rapid evolution of Wolbachia in natural populations of Drosophila

Wolbachia are maternally inherited bacteria that commonly spread through host populations by causing cytoplasmic incompatibility, often expressed as reduced egg hatch when uninfected females mate with infected males. Infected females are frequently less fecund as a consequence of Wolbachia infection. However, theory predicts that because of maternal transmission, these "parasites" will tend to evolve towards a more mutualistic association with their hosts. Drosophila simulans in California provided the classic case of a Wolbachia infection spreading in nature. Cytoplasmic incompatibility allowed the infection to spread through individual populations within a few years and from southern to northern California (more than 700 km) within a decade, despite reducing the fecundity of infected females by 15%-20% under laboratory conditions. Here we show that the Wolbachia in California D. simulans have changed over the last 20 y so that infected females now exhibit an average 10% fecundity advantage over uninfected females in the laboratory. Our data suggest smaller but qualitatively similar changes in relative fecundity in nature and demonstrate that fecundity-increasing Wolbachia variants are currently polymorphic in natural populations.

Routine Chlamydia antibody testing is of limited use in subfertile women with anovulation

The Chlamydia antibody titre (CAT) is a test used to identify subfertile couples at increased risk for tubal pathology. The usefulness of the routine performance of CAT was evaluated in a multicentre prospective cohort study, in women without regular ovulation. Consecutive couples presenting with subfertility due to an irregular menstrual cycle or amenorrhoea were included. A total of 711 women were studied, all of whom underwent CAT. Tubal status was verified in 190 of these women. Two-sided tubal pathology was found in 5% of these women, and one-sided occlusion in 10%. Of all the women in the study group, 33 (4.6%) had an abnormal CAT, of which 21 underwent further tubal testing. Tubal pathology was found in two (10%) of these 21 patients. The sensitivity and specificity of CAT were respectively 20% and 89%. Correction for verification bias increased the specificity to 96% with a drop of the sensitivity to 9%. In subfertile couples with anovulation, the performance of CAT is not useful. It is proposed that testing for tubal disease in these women is delayed until treatment with clomiphene citrate has failed.

The importance of chlamydial infections in obstetrics and gynaecology: An update

Chlamydia is now the most common notifiable infectious disease in many countries, a fact that has serious ramifications for the reproductive health of women. This review highlights the epidemiology, pathophysiology, clinical features and reproductive sequelae of the infection. Current screening and management methods are outlined. Obstetricians and gynaecologists are ideally placed to play a major role in the primary prevention of this significant sexually transmitted infection.

[Chlamydia trachomatis as an etiological factor of marital infertility--is a routine diagnostics worth to perform?]

Chlamydia trachomatis is one of the most common sexually transmitted human pathogens. Chlamydial infection is a problem concerning about 12% of young, sexually active persons at reproductive age. Because of subtle or, particularly at women, asymptomatic course, the disease may be imperceptible by patients and untreated until complications occur. When the infection spreads outside cervix and urethra,W irreversible damages in the range of genital-urinary system are often. Fever and leucocytosis can confirm the complications, occurring in the form of pelvic inflammatory disease, causing infertility. Health education, screening programs for high risk patients and proper early treatment of both sexual partners could contribute to decreasing dangerous results of chlamydial infections, especially in aspect of marital infertility problem.

[Mycoplasmatic infections and their role in marital infertility]

Mycoplasmas belong to the large group of microbes and may cause pathologic symptoms in different human organs and systems. The most of them are commensals. They are mostly detected in sexually active persons. Only few of mycoplasmatic species are unquestionable etiological factors of different human infections. They cause illness of respiratory system and kidneys. They are frequently connected with nongonococcal urethritis, epididymitis, prostatitis as well as female pelvic inflammatory disease. Mycoplasmas as etiological factors of genital organ infections have been kept in background of other pathogens for a long time. Recently, the connection between mycoplasmatic infections and marital infertility has been noticed more often. Nowadays this problem is frequently described in Polish as well as foreign scientific literature. The article is an attempt to introduce the problem of mycoplasmatic infections of urogenital male and female system. Simultaneously, it tries to answer the question whether and how they can be an essential cause of marital infertility.

Molecular mimicry and horror autotoxicus: do chlamydial infections elicit autoimmunity?

All species of the order Chlamydiales are obligate intracellular eubacterial pathogens of their various hosts. Two chlamydial species, Chlamydia trachomatis and Chlamydia pneumoniae, are primarily human pathogens, and each is known to cause important diseases. Some strains of C. trachomatis are sexually transmitted and frequently cause severe reproductive problems, primarily in women. Other strains of the organism serve as the aetiological agents for blinding trachoma, still the leading cause of preventable blindness in underdeveloped nations. C. pneumoniae is a respiratory pathogen known to cause community-acquired pneumonia. Importantly, both organisms engender an immunopathogenic response in the human host, and both have been associated with widely diverse, relatively common and currently idiopathic chronic diseases, most of which include an important autoimmune component. In this article, we explore the available experimental data regarding the possible elicitation of autoimmunity in various contexts by chlamydial infection, and we suggest several avenues for research to explore this potentially important issue further.

Prevalence of mycoplasmas in the semen and vaginal swabs of Danish stallions and mares

The reproduction rate of horses is one of the lowest within domestic livestock despite advances the veterinary medicine. Infertility in horses may be due mainly to the lack of suitable selection criteria in the breeding of horses. However, acquired infertility due to genital, bacterial infections may occur. Mycoplasmas have been implicated in genital disorders and infertility of many species including humans and horses. However, their role as commensals or pathogens of the genital tract of horses is still not determined. Bacteriological examinations made on the fossa glandis, urethra, penis and semen of stallions, showed the presence of different Mycoplasma species. Therefore our study aimed to find the prevalence of Mycoplasma species and a possible association with fertility problems in Danish riding horses. Eighty semen samples from stallions and 19 vaginal swab samples from mares were tested by PCR for presence of mycoplasmal DNA. The vaginal swab samples were also cultured in the Mycoplasma specific medium. None of the samples were positive for presence of genital mycoplasmas during the screen. The lack of genital mycoplasmas observed in this study may be due to a very extensive use of artificial insemination of modern sport horses.

Outcome of urogenital infection with Chlamydia muridarum in CD14 gene knockout mice

BACKGROUND

CD14 has been postulated to play a role in chlamydial immunity and immunopathology. There is evidence to support this role in human infections but its function in a mouse model has not been investigated.

METHODS

Female CD14 gene knockout and C57BL/6J wild type mice were infected intravaginally with Chlamydia muridarum. The infection course was monitored by detection of viable chlamydiae from serially collected cervical-vaginal swabs. The sequela of tubal factor infertility was assessed using hydrosalpinx formation as a surrogate marker.

RESULTS

A significantly abbreviated infection course was observed in the CD14 gene knockout mice but hydrosalpinx formation occurred at similar rates between the two groups.

CONCLUSION

Involvement of CD14 during chlamydial infection impedes infection resolution but this does not affect the sequela of infertility as assessed by hydrosalpinx formation.

Host Life‐History Strategy Explains Pathogen‐Induced Sterility

Virulence is often equated with pathogen-induced mortality, even though loss of fecundity is also common. But while the former may be understood as a simple consequence of lost host resources for the purposes of pathogen transmission, pathogen-induced sterility is often not associated with changes in host mortality. As a result, a separate literature has emerged to explain fecundity effects of parasitism that has not been integrated into general theories of the evolution of virulence. Here, I present a model of pathogen-induced sterility that is based on the assumption that hosts and pathogens vie for the same host resources for both reproduction and maintenance. Loss of host fecundity can then be explained by the host compensating for its future loss of resources, before infection. Such preinfection ;;fecundity compensation" may often cause preinfection investment in maintenance to be as low as postinfection levels, despite a loss of total host resources after infection. Thus, sterility is simply explained as a host life-history strategy in a system where the pathogen necessarily steals host resources for its own transmission. In certain circumstances, the pathogen may even be able to manipulate the host to redirect resources away from reproduction and toward maintenance through castration, causing gigantism.

Canine brucellosis: outbreaks and compliance

Canine infertility has many causes that must be considered during evaluation of abnormal reproductive function. An important infectious agent is Brucella canis. Classically deemed a major reason of abortion, this organism also produces infertility in stud dogs and poses a potential health hazard to dogs and humans. The State of Georgia has, out of necessity, instigated regulations to manage outbreaks and seek compliance by educating the pet owner population about this disease. A review of its etiology, methods of transmission, pathophysiology, clinical signs, diagnosis, serology and culture, pathology, treatment options, and regulated prevention featured by Georgia, are presented.

Existe-t-il un bénéfice au dépistage systématique de Chlamydia trachomatis, Mycoplasma hominis et Ureaplasma urealyticum dans les prélèvements génito-urinaires réalisés au cours d'un bilan d'infertilité ?

We conducted a prospective study on 100 couples consulting for infertility at the teaching Hospital of Tours, with the scope to determine if there is a benefit for systematic screening of Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum among genito-urinary specimen when exploring couples infertility. C. trachomatis was detected by PCR on sperm, endocervix and urine specimen. M. hominis and U. urealyticum were detected by culture on A7 agar medium and with minigaleries on sperm and endocervix specimen. Standard cultures were also performed on sperm, endocervix, vaginal and urine specimen. Only one specimen (sperm) was positive for C. trachomatis. Three percent of the specimen were positive for U. urealyticum (from which 2,5% of the sperm specimen). No specimen was positive for M. hominis. Our results show that screening of C. trachomatis, M. hominis and U. urealyticum is not systematically required for among check up of infertile couples, given the prevalence of chlamydiosis among the population studied. However, it would be interesting to perform it on a targeted population, according to anamnestic or clinical criteria. In addition, an important modification of vaginal flora was observed in 12% of cases, and 2 vaginosis were diagnosed; the putative consequences of this disequilibrium has to be further investigated.

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility

BACKGROUND

To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI).

METHODS

Blood samples were taken from 88 women with TFI and 163 control women. C. trachomatis and chlamydial heat shock protein 60 (CHSP60)-specific immunoglobulin G (IgG) antibodies were analysed using enzyme-linked immunosorbent assay (ELISA) kits. Proliferative reactivity of peripheral blood mononuclear cells was studied in vitro against Chlamydia elementary body (EB) and recombinant CHSP60 antigens.

RESULTS

C. trachomatis-specific IgG antibodies were found more frequently (43.2 versus 13.5%), and the antibody levels were higher in the TFI cases than in the controls (P < 0.001). C. trachomatis EB-induced lymphocyte responses were positive in 81.8% of the TFI cases and 58.9% of the controls (P < 0.001). Similarly, CHSP60-induced lymphocyte responses were found in 45.5% of the TFI cases and 30.7% of the controls (P < 0.001). CHSP60 antibody test was the best single test predicting TFI. Compared to cases with all four markers negative, the estimated risk for TFI was 4.1 (95% CI 1.4-11.9) among those with one positive marker and 19.9 (95% CI 6.9-57.4) among those with three to four positive markers.

CONCLUSION

Our results show that TFI prediction model can be improved by combining tests for humoral and CMI response to chlamydial antigens.

[Chlamydia trachomatis urogenital infections in women. Best diagnostic approaches]

Chlamydiae are obligate intracellular bacteria. Chlamydia trachomatis is the most common sexually transmitted disease (STD). The C. trachomatis damaging disease sequelae such as sterility is based on intense and chronic inflammation elicited and maintained by reinfection or persistent infection. The high prevalence of C. trachomatis infection reflects the long and successful adaptation of these organisms to persist in their human host population. The large group of asymptomatically infected persons is not only at risk of serious long-term sequelae but also sustains transmission within communities. C. trachomatis acute infections have been diagnosed by cell culture, direct immunofluorescence, enzyme immunoassay, direct DNA hybridization, and more recently by nucleic acid amplification tests (NAATs). In chronic or persistent chlamydial infections, the level of Chlamydia is very low and bacteria are often not viable. Such infections would be characterized by continuing positive NAATs but only intermittent isolation of viable Chlamydia and positive assays for chlamydial protein antigen. The development of NAATs has been a major advance in the field of chlamydial diagnosis. The use of NAATs associated with serology test is the best diagnosis. The introduction of assays based on amplification of genetic material has subsequently increased the sensitivity of detecting chlamydial infections and offers the opportunity to use non-invasive sampling techniques to screen for infections in asymptomatic subjects. In this article, it was proposed the best diagnosis approaches for detection of acute and chronic infections.

Molecular identification of the first human isolate belonging to the Veillonella ratti-Veillonella criceti group based on 16S rDNA and dnaK gene sequencing

Anaerobic gram-negative cocci belonging to the genus Veillonella are currently subdivided into eight species. Among them, four have been isolated either from human flora or from clinical samples during infectious processes: Veillonella atypica, V. dispar, V. parvula and V. montpellierensis. To date, the four other species have only been found in animals. In particular, V. ratti and V. criceti, since their characterization, have been exclusively reported from mouth and intestine of rodents. We report here for the first time a human isolate belonging to the V. ratti-V. criceti group recovered in mixed aerobic-anaerobic flora from a semen sample in a 24-year-old man attending the urology unit of our hospital for infertility. Identification of the isolate was based on 16S ribosomal DNA and dnaK gene sequencing. Since then, two strains of Veillonella sp. recovered from semen samples remained unidentified to the species level, and 16S rDNA-based phylogenetic analysis revealed that they might represent novel taxa within the genus Veillonella. Taken together, these observations suggest that host restriction may not exist in the genus Veillonella and that bacterial diversity remains underestimated both within this genus and in human semen.

Demonstration of Chlamydia trachomatis IgG antibodies in the male partner of the infertile couple is correlated with a reduced likelihood of achieving pregnancy

BACKGROUND

The objective of this study was to determine the prevalence of Chlamydia trachomatis among both men and women seeking help at an infertility clinic, and to prospectively follow the effect of previous infection on pregnancy rates and pregnancy outcome after a long follow-up period (mean 37 months).

METHODS

A total of 244 infertile couples was tested for C. trachomatis IgG antibodies, and IgG(+) couples were also tested for C. trachomatis DNA by PCR in a first-void urine sample. Study parameters were serology, PCR results, clinical diagnoses, treatments, pregnancy rates and pregnancy outcome. As controls, age-matched and spontaneously pregnant women were also tested with serology.

RESULTS

The prevalence of IgG antibodies was 24.2, 20.1 and 15.6% among infertile women, infertile men and control women respectively. The prevalence of C. trachomatis DNA was 6.8 and 7.1% among tested women and men respectively. The presence of C. trachomatis IgG antibodies in women was related to tubal factor infertility (TFI) (P = 0.002). Decreased pregnancy rates were seen in couples where the man was IgG(+) (P = 0.005) with no relationship to TFI. Among women who achieved pregnancy, there was no difference in pregnancy outcome between IgG(+) or negative couples.

CONCLUSIONS

C. trachomatis IgG antibodies in the man of the infertile couple was related to decreased pregnancy rates and to the presence of IgG antibodies in the woman. There was a high prevalence of asymptomatic persistent infections among infertile couples.

Endometrial endotoxin, assisted reproductive technology, and preterm birth

The failure of antibiotic prophylaxis to reduce preterm birth in women at risk and the increased rate of preterm birth in singleton pregnancy after ART may have a common explanation: persistent bacterial endotoxin in the endometrium, reported by Kamiyama et al. as an explanation for reduced fertility.

So what is the role of menstrual bacterial endotoxin?

Bacterial infections may adversely affect ART. However, the meaning and risks of menstrual endotoxin are not known.

Impact of detection of bacterial endotoxin in menstrual effluent on the pregnancy rate in in vitro fertilization and embryo transfer

OBJECTIVE

To examine whether bacterial endotoxin is detectable in menstrual effluent and to analyze a possible association between endotoxin levels and a pregnancy rate after IVF-ET.

DESIGN

Prospective observational study.

SETTING

University hospital.

PATIENT(S)

Thirty-eight infertile women undergoing endotoxin assay and IVF-ET.

INTERVENTION(S)

Endotoxin was assayed by the limulus amoebocyte lysate test.

MAIN OUTCOME MEASURE(S)

Levels of bacterial endotoxin and a pregnancy rate.

RESULT(S)

In 38 samples of menstrual effluent taken from 38 women, bacterial endotoxin was detected with a range of 7.1 to >1,000 pg/mL in 37 samples and was not detected in 1 sample. After IVF-ET, pregnancy occurred in 9 of the 38 women. The mean (+/- SD) endotoxin level in these 9 pregnant women was 71.3 +/- 52.5 pg/mL and was significantly lower compared with >236.2 +/- 333.6 pg/mL in the 29 nonpregnant women. All pregnancies occurred in 28 women with an endotoxin level of </=200 pg/mL, whereas no pregnancies occurred in 10 women with an endotoxin level of >200 pg/mL, producing the significantly higher pregnancy rate in the former group than in the latter.

CONCLUSION(S)

Bacterial endotoxin was detectable in menstrual effluent from infertile women. The pregnancy rate after IVF-ET was significantly higher in women with an endotoxin level of </=200 pg/mL than in women with an endotoxin level of >200.0 pg/mL.

Bacteriologic Findings in Ostrich (Struthio camelus) Eggs from Farms with Reproductive Failures

From January 2001 to December 2002, 543 ostrich eggs were submitted for bacteriologic investigation. The eggs were laid by 387 domesticated ostriches that suffered fertility disorders and that came from 44 farms located in different areas of Northern and Central Italy. Microbiologic investigations showed bacterial isolation in 105 (19.3%) of 543 eggs examined, with a high prevalence of enterobacteria from albumen and yolk. In only a few cases did bacterial isolation result from yolk or albumen alone. An antibiotic sensitivity test was conducted on isolates by the Kirby-Bauer disc diffusion method. This is the first report regarding the microbiologic status of eggs from ostrich farms located in different Italian regions.

Wolbachia and Cytoplasmic Incompatibility in the CaliforniaCulex pipiensMosquito Species Complex: Parameter Estimates and Infection Dynamics in Natural Populations

Before maternally inherited bacterial symbionts like Wolbachia, which cause cytoplasmic incompatibility (CI; reduced hatch rate) when infected males mate with uninfected females, can be used in a program to control vector-borne diseases it is essential to understand their dynamics of infection in natural arthropod vector populations. Our study had four goals: (1) quantify the number of Wolbachia strains circulating in the California Culex pipiens species complex, (2) investigate Wolbachia infection frequencies and distribution in natural California populations, (3) estimate the parameters that govern Wolbachia spread among Cx. pipiens under laboratory and field conditions, and (4) use these values to estimate equilibrium levels and compare predicted infection prevalence levels to those observed in nature. Strain-specific PCR, wsp gene sequencing, and crossing experiments indicated that a single Wolbachia strain infects Californian Cx. pipiens. Infection frequency was near or at fixation in all populations sampled for 2 years along a &gt;1000-km north-south transect. The combined statewide infection frequency was 99.4%. Incompatible crosses were 100% sterile under laboratory and field conditions. Sterility decreased negligibly with male age in the laboratory. Infection had no significant effect on female fecundity under laboratory or field conditions. Vertical transmission was &gt;99% in the laboratory and ∼98.6% in the field. Using field data, models predicted that Wolbachia will spread to fixation if infection exceeds an unstable equilibrium point above 1.4%. Our estimates accurately predicted infection frequencies in natural populations. If certain technical hurdles can be overcome, our data indicate that Wolbachia can invade vector populations as part of an applied transgenic strategy for vector-borne disease reduction.

[Chlamydial heat shock protein (hsp 60) and fertility disorders]

OBJECTIVE

Summarization of recent knowledge on heat shock proteins (HSPs) of human and bacterial (chlamydial) origin and their participation in fertility disturbances.

DESIGN

Review article for training of physicians (gynecologists and obstetricians).

SETTING

Veterinary Research Institute, Brno.

METHOD AND RESULTS

The subject of the study is heat shock protein--hsp60 as a significant epitope Chlamydia trachomatis. Heat shock proteins are induced as a response to various stress insults from external environment (hyperthermy, UV radiation, free oxygen radicals, heavy metals, ethanol etc.) and certain processes related to the cell cycle. Sensitization with the heat shock protein Chlamydia trachomatis and subsequent excretion of highly homologous human heat shock protein are co-operating factors in the development of fertility disturbances. Significant levels of IgA antibodies to hsp60 occur in cervical mucus of women and in seminal plasma of men with fertility disturbances.

CONCLUSION

Preceding infection C. trachomatis and resulting sensitization with chlamydial heat shock protein indicate an unfavourable prognosis of the reproductive outcome and impairs the perspective of a successful in vitro fertilization.

Comparison of serological assays for detection of Chlamydia trachomatis antibodies in different groups of obstetrical and gynecological patients

New serological enzyme immunoassays (EIAs) were compared with microimmunofluorescence (MIF) as a "gold standard" to detect Chlamydia trachomatis antibodies in different groups of obstetrical, gynecological, and subfertile patients. There were no significant differences in seroprevalence rates, except for the group of C. trachomatis-positive patients (P < 0.01). Test characteristics were calculated for Chlamydia-EIA (Biologische Analysensystem GmbH, Lich, Germany) and pELISA (Medac, Wedel, Germany). pELISA seems to be a good alternative to MIF. It has high specificity and is easier to perform.

Wolbachia infections and superinfections in cytoplasmically incompatible populations of the European cherry fruit fly Rhagoletis cerasi (Diptera, Tephritidae)

Wolbachia is an obligately intracellular, maternally inherited bacterium which has been detected in many arthropods. Wolbachia infections disperse in host populations by mechanisms such as cytoplasmic incompatibility (CI). CI leads to embryonic mortality which occurs when infected males mate with uninfected females or females with a different Wolbachia strain. Populations of the European cherry fruit fly Rhagoletis cerasi (Diptera, Tephritidae) were found to be infected by two different Wolbachia strains, wCer1 and wCer2. Superinfections with both strains occurred throughout southern and central Europe and infections with wCer1 were found in northern, western and eastern Europe. Strong unidirectional CI between European populations of R. cerasi were first reported in the 1970s. From the conformity in the recent geographical distribution of the Wolbachia infections and the CI expression patterns found 25 years ago it was deduced that wCer2 potentially causes CI in R. cerasi. The comparison of the geographical distributions indicated that wCer1 + 2 must have spread into wCer1-infected populations in some areas. In other regions, a spread of wCer1 + 2 was probably prevented by dispersal barriers. There, a sharp transition from infected to superinfected populations suggested regional isolation between wCer1 and wCer1 + 2-infected populations.