Detection of Chlamydia trachomatis in semen of artificial insemination donors by the polymerase chain reaction

Chronic testicular Chlamydia muridarum infection impairs mouse fertility and offspring development†

With approximately 131 million new genital tract infections occurring each year, Chlamydia is the most common sexually transmitted bacterial pathogen worldwide. Male and female infections occur at similar rates and both cause serious pathological sequelae. Despite this, the impact of chlamydial infection on male fertility has long been debated, and the effects of paternal chlamydial infection on offspring development are unknown. Using a male mouse chronic infection model, we show that chlamydial infection persists in the testes, adversely affecting the testicular environment. Infection increased leukocyte infiltration, disrupted the blood:testis barrier and reduced spermiogenic cell numbers and seminiferous tubule volume. Sperm from infected mice had decreased motility, increased abnormal morphology, decreased zona-binding capacity, and increased DNA damage. Serum anti-sperm antibodies were also increased. When both acutely and chronically infected male mice were bred with healthy female mice, 16.7% of pups displayed developmental abnormalities. Female offspring of chronically infected sires had smaller reproductive tracts than offspring of noninfected sires. The male pups of infected sires displayed delayed testicular development, with abnormalities in sperm vitality, motility, and sperm-oocyte binding evident at sexual maturity. These data suggest that chronic testicular Chlamydia infection can contribute to male infertility, which may have an intergenerational impact on sperm quality.

Detection of chlamydia infection within human testicular biopsies

STUDY QUESTION

Can Chlamydia be found in the testes of infertile men?

SUMMARY ANSWER

Chlamydia can be found in 16.7% of fresh testicular biopsies and 45.3% of fixed testicular biopsies taken from a selection of infertile men.

WHAT IS KNOWN ALREADY

Male chlamydial infection has been understudied despite male and female infections occurring at similar rates. This is particularly true of asymptomatic infections, which occur in 50% of cases. Chlamydial infection has also been associated with increased sperm DNA damage and reduced male fertility.

STUDY DESIGN, SIZE, DURATION

We collected diagnostic (fixed, n = 100) and therapeutic (fresh, n = 18) human testicular biopsies during sperm recovery procedures from moderately to severely infertile men in a cross-sectional approach to sampling.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The diagnostic and therapeutic biopsies were tested for Chlamydia-specific DNA and protein, using real-time PCR and immunohistochemical approaches, respectively. Serum samples matched to the fresh biopsies were also assayed for the presence of Chlamydia-specific antibodies using immunoblotting techniques.

MAIN RESULTS AND THE ROLE OF CHANCE

Chlamydial major outer membrane protein was detected in fixed biopsies at a rate of 45.3%. This was confirmed by detection of chlamydial DNA and TC0500 protein (replication marker). C. trachomatis DNA was detected in fresh biopsies at a rate of 16.7%, and the sera from each of these three positive patients contained C. trachomatis-specific antibodies. Overall, C. trachomatis-specific antibodies were detected in 72.2% of the serum samples from the patients providing fresh biopsies, although none of the patients were symptomatic nor had they reported a previous sexually transmitted infection diagnosis including Chlamydia.

LIMITATIONS, REASONS FOR CAUTION

No reproductively healthy male testicular biopsies were tested for the presence of Chlamydia DNA or proteins or Chlamydia-specific antibodies due to the unavailability of these samples.

WIDER IMPLICATIONS FOR THE FINDINGS

Application of Chlamydia-specific PCR and immunohistochemistry in this human male infertility context of testicular biopsies reveals evidence of a high prevalence of previously unrecognised infection, which may potentially have a pathogenic role in spermatogenic failure.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for this project was provided by the Australian NHMRC under project grant number APP1062198. We also acknowledge assistance from the Monash IVF Group and Queensland Fertility Group in the collection of fresh biopsies, and the Monash Health and co-author McLachlan (declared equity interest) in retrieval and sectioning of fixed biopsies. E.M. declares an equity interest in the study due to financing of fixed biopsy sectioning. All other authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Genital Chlamydia trachomatis Infections Clear More Slowly in Men Than Women, but Are Less Likely to Become Established

Background

Rigorous estimates for clearance rates of untreated chlamydia infections are important for understanding chlamydia epidemiology and designing control interventions, but were previously only available for women.

Methods

We used data from published studies of chlamydia-infected men who were retested at a later date without having received treatment. Our analysis allowed new infections to take one of 1, 2, or 3 courses, each clearing at a different rate. We determined which of these 3 models had the most empirical support.

Results

The best-fitting model had 2 courses of infection in men, as was previously found for women: “slow-clearing” and “fast-clearing.” Only 68% (57%–78%) (posterior median and 95% credible interval [CrI]) of incident infections in men were slow-clearing, vs 77% (69%–84%) in women. The slow clearance rate in men (based on 6 months’ follow-up) was 0.35 (.05–1.15) year^-1 (posterior median and 95% CrI), corresponding to mean infection duration 2.84 (.87–18.79) years. This compares to 1.35 (1.13–1.63) years in women.

Conclusions

Our estimated clearance rate is slower than previously assumed. Fewer infections become established in men than women but once established, they clear more slowly. This study provides an improved description of chlamydia’s natural history to inform public health decision making. We describe how further data collection could reduce uncertainty in estimates.

Screening for sexually transmitted infection pathogens in semen samples

The transmission of sexually transmitted infection (STI) pathogens from an infected donor to the recipient of a semen donation in assisted conception may result not only in acute infection but also in long-term reproductive complications or adverse outcomes of pregnancy, including infection of the offspring. Screening for bacterial STI pathogens, Chlamydia trachomatis and Neisseria gonorrhoeae is strongly recommended because these pathogens can cause serious reproductive complications in the recipients of semen donations and infection in their offspring. Screening for these pathogens should be performed using the most sensitive methods, such as nucleic acid amplified tests. False-negative results due to inhibitory substances in the semen sample should be monitored using amplification controls. Where specimen transport is not a problem and culture facilities are available, N gonorrhoeae can also be detected by culture. Laboratories performing screening should subscribe to proficiency programs and have strict quality controls. Although Trichomonas vaginalis, group B streptococcus and genital mycoplasmas have been associated with adverse outcomes of pregnancy, the frequent finding of these organisms in healthy individuals brings into question the validity of mandatory inclusion of these organisms in the screening panel. Although viral STI pathogens and Treponema pallidum - the causative agent of syphilis - may be detected in semen, their presence may be more sensitively detected through antibody testing of the donor. Screening donors for HIV, hepatitis B and syphilis by serology is uniformly recommended in all of the guidelines, but the value of screening either donors or semen samples for cytomegalovirus, herpes simplex viruses and human papilloma viruses is less clear.

Assessment of Chlamydia trachomatis infection of semen specimens by ligase chain reaction

Diagnostic potential of the Chlamydia trachomatis ligase chain reaction system (LCx) to assess the presence of C. trachomatis in urine and semen specimens was evaluated. Paired urine and semen specimens from 153 asymptomatic male partners of subfertile couples attending our Center for Reproductive Medicine were examined by LCx. As controls, 19 semen samples from four donors who were participating in the programme for artificial insemination were used. Of these, 12 samples had previously been shown to be C. trachomatis-positive by an in-house PCR. C. trachomatis was detected by LCx in seven of 153 (5 %) urine samples. None of the 153 semen samples tested positive by LCx. Also, none of the 12 C. trachomatis-containing control semen samples were positive by LCx. By in-house PCR, seven urine specimens and two of 153 (1 %) semen samples tested positive. The corresponding urine samples of these male partners were also C. trachomatis-positive, as well as the 12 C. trachomatis-containing samples from donors. In conclusion, LCx is not sensitive enough to assess the presence of C. trachomatis in semen specimens; therefore, this method is not recommended to routinely screen semen specimens from donors who participate in programmes for artificial insemination or male partners of subfertile couples for C. trachomatis.

Prevalence and persistence of asymptomatic Chlamydia trachomatis infections in urine specimens from Danish male military recruits

Danish male military recruits (n = 388) were included in a follow-up study to investigate the prevalence and persistence of asymptomatic Chlamydia trachomatis infections. Urine specimens were collected at enrolment and after approximately six months. C. trachomatis was detected by polymerase chain reaction (Amplicor, Roche). Questionnaires were filled out concerning sexual behaviour and clinical symptoms. The prevalence of asymptomatic C. trachomatis in Danish male military recruits was 4.6% (18 out of 388). From five C. trachomatis-positive men no follow-up sample was obtained. From the remaining 13 C. trachomatis-positive men four (31%) were treated for C. trachomatis between the two visits (outside the study protocol). Of the remaining nine men, one cleared the infection and eight men (89%) had a persistent infection. The number of lifetime sexual partners was associated with the presence of C. trachomatis at enrolment. Although based on small numbers, this follow-up study shows, in contrast to women with asymptomatic C. trachomatis infections, a high percentage of C. trachomatis persistence in asymptomatically infected males.

PCR assessment of Chlamydia trachomatis infection of semen specimens processed for artificial insemination

In order to ascertain the microbiological quality of stored semen specimens processed for artificial insemination by a donor (AID), we developed a PCR assay targeting the chlamydial plasmid to detect Chlamydia trachomatis in semen. The lower limit of detection of this assay corresponded to 2.5 to 5 elementary bodies per microl of semen. A total of 669 cryopreserved ejaculates from 97 asymptomatic donors were tested for C. trachomatis infection. Twelve ejaculates, originating from four donors, were found to be positive, indicating a 4% prevalence of C. trachomatis infection among the donor population studied. Cross-contamination between the cryopreserved specimens in the storage container was studied by typing using sequence analysis of PCR-amplified omp1 genes of the strains. Two donors were infected with serovar E, one was infected with serovar F, and one was infected with serovar K. For two donors, the duration of C. trachomatis positivity could be assessed. One donor donated C. trachomatis-positive semen for at least 4 successive months, and the other did so for at least 16 months. The occurrence of C. trachomatis infection in cryopreserved donor semen indicates that ejaculates from donors not tested for a C. trachomatis infection just prior to donation should be tested for infection by a direct test such as the PCR described here. Direct testing of semen specimens will detect not only donors with an active infection but also C. trachomatis-infected ejaculates already stored and will thus improve the microbiological quality of AID, since discrepancies in the presence of C. trachomatis in urine and semen specimens have been reported.

Screening for Chlamydia trachomatis and Ureaplasma urealyticum infection in semen from asymptomatic male partners of infertile couples prior to in vitro fertilization

In a prospective study, the prevalence of infection with Chlamydia trachomatis and Ureaplasma urealyticum was evaluated in the semen of 92 asymptomatic male partners of infertile couples using polymerase chain reaction and culture, respectively. The results were compared with the detection of serologically specific antibodies. U. urealyticum and C. trachomatis were detected in 12 (13%) and 10 (10.8%) of the tested ejaculates, respectively. One mixed infection was detected. No correlation was found between detection of the pathogens in ejaculates and the presence of specific antibodies in serum. This study therefore confirms the limited diagnostic value of serological analysis to ascertain infection with C. trachomatis or U. urealyticum. The high frequency of detection of these pathogens among asymptomatic male partners of infertile couples emphasizes their potential role in the impairment of male fertility, and the need for sensitive and specific detection methods to prevent infection of the early embryo when using new reproductive techniques such as zona pellucida hatching or intracytoplasmic microinjection.

Chlamydia trachomatis detected by ligase chain reaction in the semen of asymptomatic patients without pyospermia or pyuria

To determine whether an absence of leukocytes in semen and urine predicts an absence of Chlamydia trachomatis in asymptomatic infertile men, chlamydial DNA was detected in subjects' semen and urine by ligase chain reaction (LCR). Ninety-eight infertile men were studied, including 39 cases of oligozoospermia, 19 of azoospermia, 16 of asthenozoospermia, and 24 of normozoospermia. None of the subjects had pyospermia or pyuria. C. trachomatis was detected by LCR. Antichlamydial and antisperm antibody were also measured. C. trachomatis was detected by LCR in the semen of only 1 of 98 patients (1.02%), but not in the urine samples. In C. trachomatis-positive patients LCR, IgG, and IgA levels were higher than normal. No antisperm antibody was detected. Even if leukocytes are not observed in the semen and urine of asymptomatic infertile men, the presence of C. trachomatis in semen specimens is rarely observed. Therefore, it should be noted that the presence of C. trachomatis in such cases is addressed in the context of artificial insemination and other assisted reproductive technologies.

Markers of sexually transmitted diseases in seminal fluid of male clients of female sex workers

OBJECTIVES

To screen for certain STD markers in a group of male clients of female sex workers.

METHOD

Condoms with seminal fluid were collected at 10 "massage parlours" in Copenhagen. The seminal fluid samples were examined for HIV antibodies, markers of hepatitis B virus (HBV), Chlamydia trachomatis, and Mycoplasma genitalium.

RESULTS

All samples (n = 332) were negative for HIV antibodies. Out of 327 samples examined for HBV markers 32 (9.8%) were positive for HBV core antibodies, one of which was also positive for HBV antigen. C trachomatis could be demonstrated in six out of 122 (4.9%) samples and M genitalium in one out of 122 samples.

CONCLUSIONS

The finding of a C trachomatis prevalence of 4.9% is considerable higher than expected in men with a presumed age of 35-55 years. The demonstration of a prevalence of HBV markers of 9.8% indicates that these clients have an increased risk of HBV infection, a finding that further consolidates the recommendation of HBV vaccination of sex workers. As shown in this study, STD transmission in commercial sex may also have the client as the source.

Semen donors and STD screening

AIM

The British Andrology Society recommends screening semen donors for sexually transmitted infections to minimise the risk of pathogen transmission to the mother and fetus. The aim was to review recent findings of semen donor screening and, if appropriate, recommend changes to the screening protocol.

SUBJECTS

175 consecutive men attending for STD screening between January 1992 and December 1995 who had been preselected by the Department of Obstetrics and Gynaecology as suitable semen donors.

METHODS

Retrospective review of case notes and group comparison of demographic and sexual history data.

RESULTS

11 men (6%) had evidence of infection, excluding CMV seropositivity, at their first STD screen. After semen donation, 109 men (63%) were rescreened and, of these, 12% had positive findings. Positive findings at initial screening were predicted by a history of more than one partner in the preceding 6 months (OR 7.11, 95% CI 1.66-30.4) but it did not predict rescreening findings. Other factors such as age, marital status, employment status or past STDs were not predictive for either screen.

DISCUSSION

Less than 20% of initial volunteers meet the full criteria of high quality post-thaw semen, no transmissible genetic disorders, and no transmissible pathogens. Sexual history may predict but would not alone preclude all positive STD screening findings. It is essential that sequential STD screening of donors continues and that genitourinary physicians should be involved in this process. Validation of newer diagnostic techniques as screening tests in this setting is required.

Chlamydial antibodies in semen: search for "silent" chlamydial infections in asymptomatic andrological patients

The importance of a serological diagnostic workup in male genitourinary infections with Chlamydia trachomatis and its relevance for male infertility is still under debate. In a prospective study, antichlamydial serum and seminal plasma antibodies of 131 consecutive patients (mean age 31: 20-57) without evidence of acute urethritis and with negative urethral chlamydial culture were investigated. The antibody determination was carried out with a genus specific rELISA. In patients with positive seminal plasma IgA, chlamydial genome was evaluated by polymerase chain reaction (PCR). The results were associated with standard semen parameters according to evaluated WHO guidelines. Specific serum IgG antibodies were found in 51 patients (38.9%), IgA in 39 (29.7%); both antibodies were present in 25 patients (19%). Seminal plasma IgG was demonstrable in seven patients (5.3%), IgA in 26 (19.9%), and five patients were positive for both antibody classes (3.8%). Of the 26 men positive for specific seminal plasma IgA antibodies 12 did not demonstrate a serum antibody reaction. Only two patients with positive IgA titers in their seminal plasma showed a positive chlamydial genome reaction in PCR (8%). Men with antichlamydial seminal plasma IgA and/or IgG did not differ significantly in any of the standard semen sperm parameters from men testing negative for antibodies, with the exception of peroxidase positive leukocytes (p < 0.01), nor was there an association between any of the ejaculate parameters and any of the antibody titers. The data of about 40% antichlamydial serum antibody findings without a significant association with seminal plasma antibodies and no clinical signs of infection seem to reflect a history of urogenital infection. The unique presence of seminal plasma IgA in 12 of 26 cases may be caused by a local antibody response due to a "silent" infection. Thus, seminal plasma IgA was associated with signs of inflammation, whereas, there was no association with genome or pathogen demonstration. Therefore, it appears to be necessary to reevaluate genus-specific seminal plasma IgA antibodies with a species-specific microimmunofluorescence test and to compare these results with a genome screening using PCR or in situ hybridization.

Detection of Chlamydia trachomatis in semen by antibody-enzyme immunoassay compared with polymerase chain reaction, antigen-enzyme immunoassay, and urethral cell culture

OBJECTIVE

To compare the results obtained by four different techniques for the detection of Chlamydia trachomatis in the male genital tract.

DESIGN

Prospective study.

SETTING

Andrology unit of a university hospital.

PATIENTS

Male infertility patients.

INTERVENTIONS

Analysis of semen samples and urethral swabs for the presence of C. trachomatis by recombinant antibody-enzyme-linked immunosorbent assay (rELISA), polymerase chain reaction (PCR), antigen-enzyme immunoassay (EIA) and McCoy cell culture.

MAIN OUTCOME MEASURE

Detection of C. trachomatis.

RESULTS

In 57 of 205 semen samples (27.8%) immunoglobulin A-antibodies against C. trachomatis were found. In contrast, only 1 of 56 semen samples (1.8%) was positive for C. trachomatis-DNA by PCR, only 1 of 139 semen samples (0.7%) was positive by antigen-EIA, and only 4 of 173 urethral swabs (2.3%) grew C. trachomatis in cell culture.

CONCLUSIONS

The discrepancy of positive results found by the antibody-rELISA and direct methods for the detection of C. trachomatis indicates successful eradication of the microorganism in > 90% of antibody-positive men. Therefore, detection of antibodies against C. trachomatis in seminal plasma appears to be of limited diagnostic value.

Comparison of polymerase chain reaction, direct immunofluorescence, cell culture and enzyme immunoassay for the detection of Chlamydia psittaci in bull semen

The polymerase chain reaction (PCR), direct immunofluorescence (DIF; JMAGEN Chlamydia, DAKO Diagnostics, UK), cell culture (CC) and enzyme immunoassay (EIA; Syva Micro Trak) were evaluated for detection of Chlamydia psittaci in bull semen. Three specimens were collected from each of 47 bulls at 3-6 month intervals (134 samples). Judging by the number of samples tested (n = 134), PCR showed a sensitivity of 90.9%, DIF of 93.9%, CC of 72.7% and EIA of 81.8%. PCR, DIF, CC and EIA were 100% specific, respectively. Of the 47 bulls the maximum number of chlamydia-positive animals (n = 14) was revealed when repeated tests were made by PCR. PCR detected 21.4% more positives than DIF and CC and 35.7% more than EIA. Although CC was less sensitive judging by the number of samples tested, it was as sensitive as DIF (78.6%) when judged by the number of bulls investigated. All bulls found to be chlamydia-positive remained so throughout the investigation, which lasted 18 months.