The rôle of Chlamydia trachomatis in genital-tract and associated diseases

The combined impact of persistent infections and human genetic variation on C-reactive protein levels

Multiple human pathogens establish chronic, sometimes life-long infections. Even if they are often latent, these infections can trigger some degree of local or systemic immune response, resulting in chronic low-grade inflammation. There remains an incomplete understanding of the potential contribution of both persistent infections and human genetic variation on chronic low-grade inflammation. We searched for potential associations between seropositivity for 13 persistent pathogens and the plasma levels of the inflammatory biomarker C-reactive protein (CRP), using data collected in the context of the UK Biobank and the CoLaus|PsyCoLaus Study, two large population-based cohorts. We performed backward stepwise regression starting with the following potential predictors: serostatus for each pathogen, polygenic risk score for CRP, and demographic and clinical factors known to be associated with CRP. We found evidence for an association between Chlamydia trachomatis (P-value = 5.04e - 3) and Helicobacter pylori (P-value = 8.63e - 4) seropositivity and higher plasma levels of CRP. We also found an association between pathogen burden and CRP levels (P-value = 4.12e - 4). These results improve our understanding of the relationship between persistent infections and chronic inflammation, an important determinant of long-term morbidity in humans.

Animal models for studying female genital tract infection with Chlamydia trachomatis

Chlamydia trachomatis is a Gram-negative obligate intracellular bacterial pathogen. It is the leading cause of bacterial sexually transmitted disease in the world, with more than 100 million new cases of genital tract infections with C. trachomatis occurring each year. Animal models are indispensable for the study of C. trachomatis infections and the development and evaluation of candidate vaccines. In this paper, the most commonly used animal models to study female genital tract infections with C. trachomatis will be reviewed, namely, the mouse, guinea pig, and nonhuman primate models. Additionally, we will focus on the more recently developed pig model.

Chlamydia trachomatis recombinant MOMP encapsulated in PLGA nanoparticles triggers primarily T helper 1 cellular and antibody immune responses in mice: a desirable candidate nanovaccine

We recently demonstrated by in vitro experiments that PLGA (poly D, L-lactide-co-glycolide) potentiates T helper 1 (Th1) immune responses induced by a peptide derived from the recombinant major outer membrane protein (rMOMP) of Chlamydia trachomatis, and may be a promising vaccine delivery system. Herein we evaluated the immune-potentiating potential of PLGA by encapsulating the full-length rMOMP (PLGA-rMOMP), characterizing it in vitro, and investigating its immunogenicity in vivo. Our hypothesis was that PLGA-rMOMP triggers Th1 immune responses in mice, which are desirable prerequisites for a C. trachomatis candidate nanovaccine. Physical-structural characterizations of PLGA-rMOMP revealed its size (approximately 272 nm), zeta potential (−14.30 mV), apparent spherical smooth morphology, and continuous slow release pattern. PLGA potentiated the ability of encapsulated rMOMP to trigger production of cytokines and chemokines by mouse J774 macrophages. Flow cytometric analyses revealed that spleen cells from BALB/c mice immunized with PLGA-rMOMP had elevated numbers of CD4+ and CD8+ T cell subsets, and secreted more rMOMP-specific interferon-gamma (Th1) and interleukin (IL)-12p40 (Th1/Th17) than IL-4 and IL-10 (Th2) cytokines. PLGA-rMOMP-immunized mice produced higher serum immunoglobulin (Ig)G and IgG2a (Th1) than IgG1 (Th2) rMOMP-specific antibodies. Notably, sera from PLGA-rMOMP-immunized mice had a 64-fold higher Th1 than Th2 antibody titer, whereas mice immunized with rMOMP in Freund’s adjuvant had only a four-fold higher Th1 than Th2 antibody titer, suggesting primarily induction of a Th1 antibody response in PLGA-rMOMP-immunized mice. Our data underscore PLGA as an effective delivery system for a C. trachomatis vaccine. The capacity of PLGA-rMOMP to trigger primarily Th1 immune responses in mice promotes it as a highly desirable candidate nanovaccine against C. trachomatis.

Spolno Prenosljive Okužbe Z Bakterijo Chlamydia Trachomatis V Sloveniji / Sexually Transmitted Infections With The Bacteria Chlamydia Trachomatis In Slovenia

Namen:Namen prispevka je na osnovi sistematičnega pregleda objavljenih raziskav oceniti prevalenco genitalnihokužb z bakterijo Chlamydia trachomatis v Sloveniji.

Metode:Pregledana je bila literatura v dveh elektronskih podatkovnih zbirkah, in sicer v zbirki PubMed z uporabokombinacije ključnih besed »chlamydia« in »Slovenia« ter v zbirki Cobiss Slovenija s pomočjo ključnih besed»klamidija«, »chlamidia« in »chlamydia«. Vključene so raziskave, ki so bile v navedenih zbirkah vpisane do vključnokonca novembra 2011 in so vsebovale izsledke o pogostosti klamidijskih okužb med prebivalci Slovenije.

Rezultati:V obdobju od leta 1980 do vključno konca novembra 2011 je bilo objavljenih 18 raziskav, ki so ustrezaleiskalnim merilom. Večina raziskav je bila izvedena na različnih skupinah prebivalcev Slovenije in ne na verjetnostnihnacionalnih vzorcih. Klamidijska okužba je bila ugotovljena v 0-19% primerih. Pri preiskovancih z nekaterimi stanji,ki so lahko povezana z višjo prevalenco spolno prenosljivih okužb, je bila klamidijska okužba ugotovljena v 4,9-19%,pri tistih, ki takšnih stanj niso imeli opisanih, pa v 0-16,5%. Pet raziskav je bilo končanih po letu 2000 in pri teh jebila klamidijska okužba ugotovljena v 0-6,5%. Največ okuženih je med starimi 20 in 24 let.

Zaključki:Chlamydia trachomatis je pomembna povzročiteljica spolno prenosljivih okužb v Sloveniji. Večineklamidijskih okužb zaradi nizkih stopenj testiranja ne prepoznamo in tako zamujamo številne priložnosti za zdravljenjein preprečevanje kasnih posledic, predvsem za reproduktivno zdravje žensk

Chlamydia trachomatis vaccine research through the years

Chlamydia trachomatis is a Gram-negative obligate intracellular bacterium. It is the leading cause of bacterial sexual transmitted infections (STIs). World Health Organization figures estimated that over 90 million new cases of genital C. trachomatis infections occur worldwide each year. A vaccination program is considered to be the best approach to reduce the prevalence of C. trachomatis infections, as it would be much cheaper and have a greater impact on controlling C. trachomatis infections worldwide rather than a screening program or treating infections with antibiotics. Currently, there are no vaccines available which effectively protect against a C. trachomatis genital infection despite the many efforts that have been made throughout the years. In this paper, the many attempts to develop a protective vaccine against a genital C. trachomatis infection will be reviewed.

Validation of the Chlamydia trachomatis genital challenge pig model for testing recombinant protein vaccines

Chlamydia trachomatis is a Gram-negative obligate intracellular bacterial pathogen that is the leading cause of bacterial sexually transmitted disease in humans in developing countries. A vaccination programme is considered to be the best approach to reduce the prevalence of C. trachomatis infections. However, there are still no commercial C. trachomatis vaccines. In order to develop effective C. trachomatis vaccines, it is important to identify those antigens that elicit a protective immune response, and to develop new and adequate methods and adjuvants for effective vaccine delivery, as conventional methods have failed to induce protective immunity. In order to test different vaccine candidates, animal models are needed. Former studies have used non-primate monkeys, mice or guinea pig infection models. The present study used a pig model for testing recombinant protein vaccines. Two recombinant proteins, polymorphic membrane protein G (PmpG), and secretion and cellular translocation protein C (SctC), were tested for their ability to create protection in a pig C. trachomatis challenge model. The vaccines were administered subcutaneously with GNE adjuvant. Six weeks later, animals were challenged intravaginally with C. trachomatis serovar E. After a further 4 weeks, the pigs were euthanized. PmpG-immunized pigs were better protected than pigs immunized with the less promising SctC candidate vaccine antigen. Interestingly, significant protection was apparently not correlated with a strong humoral immune response upon subcutaneous immunization. In conclusion, the pig model is useful for studying the efficacy of vaccine candidates against genital human C. trachomatis infection.

Identification of immunodominant antigens of Chlamydia trachomatis using proteome microarrays

Chlamydia trachomatis is the most common bacterial sexually transmitted pathogen in the world. In order to control this infection there is an urgent need to formulate a vaccine. Identification of protective antigens is required to implement a subunit vaccine. To identify potential antigen vaccine candidates, three strains of mice, BALB/c, C3H/HeN and C57BL/6, were inoculated with live and inactivated C. trachomatis mouse pneumonitis (MoPn) by different routes of immunization. Using a protein microarray, serum samples collected after immunization were tested for the presence of antibodies against specific chlamydial antigens. A total of 225 open reading frames (ORF) of the C. trachomatis genome were cloned, expressed, and printed in the microarray. Using this protein microarray, a total of seven C. trachomatis dominant antigens were identified (TC0052, TC0189, TC0582, TC0660, TC0726, TC0816 and, TC0828) as recognized by IgG antibodies from all three strains of animals after immunization. In addition, the microarray was probed to determine if the antibody response exhibited a Th1 or Th2 bias. Animals immunized with live organisms mounted a predominant Th1 response against most of the chlamydial antigens while mice immunized with inactivated Chlamydia mounted a Th2-biased response. In conclusion, using a high throughput protein microarray we have identified a set of novel proteins that can be tested for their ability to protect against a chlamydial infection.

Immunization with the Chlamydia trachomatis major outer membrane protein, using the outer surface protein A of Borrelia burgdorferi as an adjuvant, can induce protection against a chlamydial genital challenge

Two strains of mice C3H/HeN (H-2(k)) and BALB/c (H-2(d)) were immunized with the Chlamydia trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP) using the Borrelia burgdorferi outer surface protein A (OspA) as an adjuvant. As a control, groups of mice were inoculated with ovalbumin instead of MOMP. Female mice were immunized using three different routes: intramuscular (i.m.) plus subcutaneous (s.c.), intranasal (i.n.) and perivaginal and perisacral (p.vag.+p.sac.). Significant humoral and cell mediated immune responses developed particularly in mice inoculated by the i.m.+s.c. routes as determined by the levels of chlamydial specific antibody in the serum and genital secretions and a T-cell proliferative assay. Following immunization the animals were challenged in the genital tract with C. trachomatis MoPn and the course of the infection followed by vaginal cultures. Significant protection against infection was achieved in the C3H/HeN mice inoculated i.m.+s.c. with MOMP+OspA, as shown by the intensity and duration of vaginal cultures, and by the number of mice with positive cultures. On the other hand in BALB/c mice there was only a decrease in the number of animals with positive vaginal cultures. Six weeks after the challenge the mice were mated and the outcome of the pregnancy evaluated. In both the C3H/HeN and the BALB/c mice immunized i.m.+s.c. with MOMP+OspA there was significant protection against infertility as shown by the number of animals with bilateral fertility and number of embryos per uterine horn. In conclusion, immunization using C. trachomatis MOMP, and B. burgdorferi OspA as an adjuvant, can induce significant protection against a chlamydial genital challenge.

Vaccination of mice with DNA plasmids coding for the Chlamydia trachomatis major outer membrane protein elicits an immune response but fails to protect against a genital challenge

A DNA plasmid encoding the gene of the major outer membrane protein (MOMP) of the Chlamydia trachomatis mouse pneumonitis (MoPn) serovar and three plasmids containing the variable domains (VD) of the MOMP were constructed. Female mice were inoculated with the plasmids and 60 days later were challenged in the genital tract with C. trachomatis. Six weeks after challenge female mice were caged with male mice and the course of the mating followed. Mice immunized with the MOMP plasmids mounted weak humoral and cell mediated immune responses. However, following the genital challenge no significant differences in vaginal shedding were observed between the groups immunized with the MOMP and control plasmids. In addition, the fertility rates were similar in the experimental and negative control groups. In conclusion, vaccination with DNA plasmids encoding the MOMP elicited a modest immune response but did not protect against infection or disease.

Monoclonal immunoglobulin A antibody to the major outer membrane protein of the Chlamydia trachomatis mouse pneumonitis biovar protects mice against a chlamydial genital challenge

In order to analyze the protective role that IgA may play in a chlamydial infection two IgA monoclonal antibodies (mAb), MoPn 4-2 and MoPn 13-2, were raised against the major outer membrane protein (MOMP) of the Chlamydia trachomatis mouse pneumonitis (MoPn) biovar. mAb MoPn 4-2 was found to be serovar specific while mAb MoPn 13-2 was species specific. mAb MoPn 4-2 recognized a surface exposed conformational epitope as shown by its ability to bind to native EBs and nonreduced MOMP while failing to bind to heat and trypsin treated EBs, to reduced MOMP and to synthetic MOMP peptides. In contrast, mAb MoPn 13-2 recognized a nonconformational epitope since it was able to bind treated EBs, to reduced MOMP and to the synthetic peptide MTTWNPTISGSGI located in variable domain 4 of the MOMP. Both mAbs agglutinated intact EBs and had in vitro neutralizing activity. However, mAb MoPn 4-2 had a 20-fold higher in vitro neutralizing ability when compared to mAb MoPn 13-2 (50% neutralization at 5 micrograms ml-1 vs 100 micrograms ml-1). In an in vitro in vivo infectivity assay, mAb MoPn 4-2 protected mice against infertility when C. trachomatis MoPn elementary bodies were preincubated with the mAb before inoculation. In addition, passive transfer of mAb MoPn 4-2 resulted in significant protection as measured by a decrease in the number of mice infected, and in the intensity and duration of vaginal shedding. These results support previous findings suggesting that IgA antibodies can play a role in protection against a chlamydial infection, and further encourage work to develop vaccination strategies that elicit mucosal immunity.

Evaluation of Chlamydia psittaci subfraction and subunit preparations for their protective capacities

A mouse toxicity potency test was used to evaluate the protective capacity of Chlamydia psittaci (Baker strain) subfraction and subunit preparations. The elementary body (EB), Chlamydial outer membrane complex (COMC), major outer membrane protein (MOMP), lipopolysaccharide (LPS), and MOMP mixed together with LPS were utilized as antigens in vaccine preparation. The EBs and COMCs were prepared by centrifugation and detergent extraction as previously described for Chlamydia trachomatis. Isolation and purification of MOMP and LPS were achieved by subjecting infected tissue culture fluids to polyacrylamide gel electrophoresis and subsequent elution from the gel. Chromatographic purification of the MOMP from EBs resulted in a preparation which also contained minor quantities of LPS. After vaccination and intraperitoneal challenge with C. psittaci (Cello strain), the MOMP presented in EBs, COMCs or in a purified form, was capable of protecting mice from death, whereas LPS did not demonstrate this capability. Further comparison of the protective capacity of these antigens indicated that the electrophoretically purified MOMP was the least protective when suboptimal levels of antigens were administered to mice. However, the level of protection afforded by electrophoretically purified MOMP could be increased to that observed with the chromatographically purified MOMP by the addition of electrophoretically purified LPS to the vaccine. These results suggest that the MOMP is the major protective antigen of C. psittaci and that the LPS component, although not protective on its own, may play a role in the potentiation of a protective immune response.

Interpretation of Chlamydia trachomatis antibody response in chlamydial oculogenital infection

OBJECTIVE

To study: (a) the chlamydial antibody response (to the D-K serovars) using the micro-immunofluorescence (micro-IF) test in the following groups: (I) chlamydial genital infection only, (II) chlamydial ocular infection only, (III) combined chlamydial ocular and genital infection (oculo-genital infection), (IV) chlamydial ocular infection with chlamydia-negative non-gonococcal urethritis, (V) adenovirus conjunctivitis (control group 1), (VI) male partners of group I-IV with no chlamydial oculogenital infection or non-gonococcal urethritis (control group 2) (b) the cross reactivity of antibodies in patients' sera between the three chlamydial species and within the serovars of C trachomatis in those with culture-positive chlamydial oculo-genital infection.

SETTING

oculogenital (diagnostic) clinic at Moorfields Eye Hospital, London, UK.

SUBJECTS

209 consecutive patients attending the clinic with Chlamydia trachomatis oculogenital infection and 86 patients with adenovirus conjunctivitis (control group 1) and 55 male partners with no evidence of chlamydial oculogenital infection or non-gonococcal urethritis (control group 2).

RESULTS

Of all the patients with proven chlamydial oculogenital infection, 10.5% (22/209) and 94% (197/209) had IgM and IgG antibodies respectively. The geometric mean IgG antibody titres (GMT) were 1:98, 1:123, 1:245 and 1:101 in groups I to IV respectively. The IgG GMT values seen in control groups 1 and 2 were 1:45 and 1:36 respectively. Only 2/86(2%) patients in group V (control group 1) had IgG chlamydial antibodies of 1:32 and 1:64, whilst only 1/55(1.8%) and 4/55(7.3%) of patients in group VI(control group 2) had chlamydial IgG antibody titres of > or = 1:256 and > or = 1:128 respectively. A four-fold rise or fall in IgG antibody titre occurred in 56%(107/192) of patient groups I-IV over 2-6 weeks. Low titre cross-reactive antibody responses against different chlamydial species and serovars were commonly seen; 71%(148/209) of all patients showed cross-reactivity with Chlamydia pneumoniae or psittaci species or both, whilst 92% (193/209) of patients showed some level of cross reactivity to other pooled serovars of C trachomatis (A-C and L 1-3).

CONCLUSIONS

Serological diagnosis of chlamydial infection as evidenced by a positive IgM antibody response, high IgG titre (> or = 1:256) or > or = 4-fold rise or fall in IgG antibody titre was seen in 78%(163/209) of patients with culture-positive chlamydial oculogenital infection. Chlamydial IgG antibody titres of > or = 1:256 had a sensitivity of 42.6%, specificity of 98.2%, positive predictive value of 98.8% and a negative predictive value of 31% for chlamydial infection at any site, when considering groups I-IV and control group 2. In this study of 216 patients with conjunctivitis, a positive IgG antibody response (titre > or = 1:16) had a sensitivity of 98.5%, specificity of 97.7%, positive predictive value of 98.5% and a negative predictive value of 97.7%, for chlamydial conjunctivitis. Patients with dual chlamydial infection of conjunctiva and genital tract had a higher IgG GMT titre than those with ocular or genital infection alone: infection at a second site may produce an anamnestic response. Although the micro-IF test is a useful adjunct for the diagnosis of chlamydial infection, cross-reactivity between different chlamydial species and serovars is common. Chlamydial seroepidemiological studies should be interpreted with caution, as studies may attribute a serological response to a particular species or serovar in a setting where two or more are prevalent.

Rapid diagnosis of chlamydial respiratory infection in children

A study was undertaken to determine the incidence of chlamydial respiratory infection in paediatric patients during a 12-month period by antigen detection. Nasopharyngeal aspirates (NPA) from 514 patients were screened for genus-specific chlamydia antigen using the Pharmacia Chlamydia enzyme immunoassay (EIA) and Kallestad immunofluorescence (IF) assays. EIA screen-positive samples were confirmed by specific blocking antibody. Specimens which were EIA positive or IF positive were cultured for chlamydia. The NPAs from 7 patients were positive in the EIA and IF assays. Four of these patients were culture positive for chlamydia. Our results showed that the incidence of chlamydia respiratory infection by antigen detection was 1.4% or 0.8% if confirmed by culture.

Association of Mycoplasma genitalium with acute non-gonococcal urethritis

Chlamydia trachomatis is known to be a cause of acute non-gonococcal urethritis (NGU), though the aetiology of this disorder is not fully understood. Mycoplasma genitalium has been isolated from a few men with NGU, but culture has remained difficult and reliable detection became possible only with a specific polymerase chain reaction (PCR). We have used the PCR to examine the role of M genitalium in NGU. M genitalium was detected in urethral samples from 24 (23%) of 103 men with symptoms, signs, or both, of acute NGU, but from only 3 (6%) of 53 men without NGU (p < 0.006). This association was independent of the presence of C trachomatis and could not be explained by differences in age, ethnic, origin, lifetime number of sexual partners or a change in sexual partner during the previous 3 months. The clinical response of the mycoplasma-positive men to doxycycline treatment was at least as satisfactory as that of the chlamydia-positive men. These findings suggest that the association of M genitalium with NGU is likely to be causal, a notion consistent with the known virulence characteristics of this microorganism and its ability to cause urethritis in male sub-human primates.

Evaluation of laparoscopy and endocervical swab in the diagnosis of Chlamydia trachomatis infection of the female genital tract

A group of 60 consecutive women admitted to the gynaecology department of Eastbourne District General Hospital for pelvic pain were entered into this study. Evidence of C. trachomatis infection of the genital tract was investigated by detection of chlamydial lipopolysaccharide antigen in the peritoneal fluid collected from the pouch of Douglas during laparoscopy and in the endocervical swab. The test used was an Enzyme-Linked Immunosorbent Assay (ELISA). Peritoneal fluid was positive in 11 subjects (18%, P < 0.05), endocervical swab was positive in 3 (5%, P < 0.05). The difference was statistically significant (P = 0.01, two tailed test at 1% level). Ten women with a positive ELISA on the peritoneal fluid had a negative cervical swab, 2 women with a positive cervical swab had negative peritoneal fluid and in only one woman were both cervical swab and peritoneal fluid positive.

Chlamydial cervicitis: role of culture, enzyme immunoassay and Giemsa cytology in diagnosis

Three different laboratory tests were carried out to find the occurrence of chlamydial infections in a selected group of 150 female patients presenting clinically with cervicitis. The tests included isolation using a cell culture system, enzyme immunoassay (EIA) for antigen detection and Giemsa cytology of endocervical smears. Contrary to earlier reports on cytological diagnosis of chlamydial cervicitis, endocervical smears stained by Giemsa stain and EIA for antigen detection were found to be of comparable sensitivity and specificity (73.1% and 86.3% for smear, and 76.1% and 90.9% for EIA, respectively) when cell culture was used as the gold standard.

Evaluation of two ELISA's for detecting Chlamydia trachomatis from endocervical swabs

Two enzyme immunoassays (EIAs) detecting Chlamydia trachomatis from endocervical swabs, Syva MicroTrak (MT) and Abbott Chlamydiazyme (CZ), were compared with a tissue culture (TC) standard. Initially, 8% (100 of 1250) of specimens were TC positive, yielding sensitivities of 94% (94 of 100) for MT and 79% (79 of 100) for CZ with identical 98% specificities (1129 of 1150 for MT and 1130 of 1150 for CZ). Discrepant specimens were retested by both EIAs and assayed for elementary bodies (EBs) by a fluorescent antibody test. After discrepancy analysis, 9.5% (118) of 1240 patients were either TC or EB positive, yielding sensitivities of 94.1% for MT (111 of 118) and 79.7% for CZ (94 of 118) with identical specificities of 100% (1122 of 1122). These results indicate that the MT is significantly more sensitive (p less than 0.05, McNemar test) than CZ in detecting C. trachomatis from endocervical swabs.

Recurrent arthritis in Reiter's syndrome: a function of inapparent chlamydial infection of the synovium?

Present or prior infection with any of several common bacterial pathogens has been strongly implicated in the development of Reiter's syndrome (RS). However, because Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen in the western hemisphere, this organism has emerged as a major causative agent of the disease. An important but as yet poorly understood aspect of chlamydia-related RS is the recurrence of active arthritis in the absence of any overt infection or reinfection with the organism. In this article, a large body of published clinical and experimental observations strongly suggesting that some chlamydial infections in humans can be inapparent--not detectable by standard culture or antibody-based laboratory screening methods--is reviewed. The authors' own initial molecular genetic studies, which support that contention, are summarized. Based on these data, the argument is developed that not only does inapparent chlamydial infection occur in humans, but such infections may have significant consequences in terms of the pathogenesis of RS, including the possible causation of recurrent episodes of disease in the absence of active infection. The therapeutic implications of potential inapparent chlamydial infections as they relate to RS are discussed.

Aetiology of non-gonococcal urethritis: a possible relation to other infections

Chlamydia trachomatis can be identified in up to 60% of cases of nongonococcal urethritis (NGU) and the aetiology of most of the remainder is obscure. This paper reports a role for other genitourinary (GU) infections such as candidiasis, warts and herpes simplex, in the causation of NGU. One hundred and ten men fulfilled the entry criteria which included the probability that their contacts would attend the department. Fifty-four of the 110 men had GU infections other than NGU; 56 had no other infections. NGU was detected in 31 (57%) of cases with other GU infections and 8 (26%) were chlamydiae-positive: in contrast NGU was found in only 10 (18%) of those with none of the other infections and 3 (30%) were chlamydiae-positive. Chlamydiae-negative NGU was, therefore, more common in those with other GU infections. Forty-five (86%) of 52 contacts of 41 patients with NGU had various GU infections such as candidosis and anaerobic vaginosis, in contrast with other GU infections in only 7 (23%) of 30 contacts of men with no other GU infections. Other GU infections in patients and their contacts appeared significantly related to the presence of chlamydiae-negative NGU.

Isolation of Bacteroides ureolyticus from the genital tract of men with and without non-gonococcal urethritis

Urethral specimens from 247 heterosexual men--118 patients with non-gonococcal urethritis and 129 controls with no evidence of urethritis--were examined for the presence of Bacteroides ureolyticus. Bacteroides ureolyticus was isolated from 45 (34.9%) of the controls and from 31 (26.3%) of the urethritis patients; there was no significant difference between these rates (p = 0.1). There was no association between the density of Bacteroides ureolyticus on primary isolation plates in either group.

Lymphogranuloma venereum of the tonsil

A case of lymphogranuloma venereum of the tonsillar lymph tissue is presented. The similarities of tonsils to cervical lymph nodes are discussed and the importance of histological examination of abnormal tonsil tissue is reiterated.

Chlamydia trachomatis in reactive arthritis

Evidence of deposition of chlamydial antigen in the joint was sought in 10 patients (9 of them male) with classic sexually acquired reactive arthritis, 15 women with unclassified seronegative oligoarthritis involving the knee and 15 individuals with established rheumatic disorders not associated with genital-tract or other infections. Using a fluorosceinated monoclonal antibody to the major outer membrane protein of Chlamydia trachomatis (MicroTrak, Syva) in a direct immunofluorescence test, particulate antigen with physical characteristics of chlamydial elementary bodies was seen in synovial fluid cell smears or synovial biopsies, or both, from 6, 5, and 0 patients, respectively. No typical chlamydial intracellular inclusions were seen. Corroborative evidence of recent chlamydial infection was provided by the finding of high titres of serum chlamydial antibody in all antigen-positive patients with sexually acquired reactive arthritis, including 3 from whom a genital-tract isolate was obtained, and 3 of the 5 women with unclassified arthritis. It is postulated that Chlamydia trachomatis organisms reach the joint during acute genital-tract infection, and the processing and presentation by class I major histocompatibility determinants of chlamydial antigens is a critical step in the initiation of reactive arthritis in some patients.

Comparison of buffalo green monkey cells and McCoy cells for isolation of Chlamydia trachomatis in a microtiter system

A total of 1,229 urogenital samples of patients with sexually transmitted diseases and prostitutes were inoculated simultaneously in McCoy cells and Buffalo green monkey (BGM) cells by using a microtitration technique. BGM cells proved to be slightly more sensitive than McCoy cells, and they usually showed more and larger inclusions and were more resistant to cytotoxic substances in samples. The decrease in sensitivity as a result of mycoplasmal contamination was much more prominent in McCoy cells than in BGM cells.

Chlamydia trachomatis infections in infants

In recent years considerable progress has been made in understanding chlamydial infections. The spectrum of pediatric Chlamydia trachomatis infection includes neonatal inclusion conjunctivitis, infantile pneumonia, occasional respiratory or genital tract infections in older children and sexually transmitted diseases in adolescents. The role of maternal chlamydial infection in prematurity and in perinatal death is currently an area of active study. We outline the current knowledge of the biologic characteristics of C. trachomatis, the epidemiologic features of chlamydial infection, and the clinical aspects, diagnosis and treatment of neonatal chlamydial infections.

Characteristics of inflammatory cells in urethral smears from men with non-gonococcal urethritis

Differential cell counts in inflammatory exudates were undertaken in urethral smears from men with non-gonococcal urethritis (NGU) for the first time, recurrent NGU (presumably reinfection) after a new sexual contact, or persistent NGU (in patients with no recent history of sexual exposure). Patients experiencing first episodes of NGU had significantly higher macrophage counts, both in relative and absolute terms, than the other two groups, regardless of the presence or absence of Chlamydia trachomatis in the urethral culture. The estimated total inflammatory cell count (ETICC) in the urethral exudate was assessed by counting the number of inflammatory cells in the first voided urine. The ETICC was significantly lower in patients with persistent NGU but no recent history of sexual exposure than in patients with NGU for the first time or with NGU presumably caused by a new infection. The ETICC in all three groups of patients was significantly higher than in controls. A more precise definition of NGU or more reproducible methods of diagnosis may possibly differentiate patients without an infective cause.

Chlamydia trachomatis among sexually active teenage girls. Lack of correlation between chlamydial infection, history of the patient and clinical signs of infection

Cultures for Chlamydia trachomatis were obtained from 1012 teenage girls attending an adolescence clinic mainly for family planning; C. trachomatis was isolated from 174 (17.2%). The proportion of chlamydia-positive girls varied between 15.7% and 28.5% depending whether or not there were symptoms and signs of infection. Neither the history nor the finding at pelvic examination offered conclusive evidence for or against the presence of an infection with C. trachomatis. Of the chlamydia-positive, untreated, asymptomatic girls, 17.5% developed symptoms of a genital infection within 3 months. There was a statistically significant difference in the proportion of positive cultures by the two investigators, suggesting that the procedure for specimen collection is of great importance.

Diagnosis of Chlamydia trachomatis infection--culture versus serology

The diagnostic value of different laboratory methods in detecting Chlamydia trachomatis infections in high risk groups was analysed. The efficiency of a direct specimen test was compared with serology (IgG and IgM ELISA) and culture in L929 cells, stained either with fluorescein conjugated monoclonal antibodies or with iodine. Patients (no. = 1041) with localized genital infections attending a STD clinic, sexual contacts and patients with ascending infections from urological and gynecological clinics were examined. Chlamydia trachomatis was detected in 225 patients: 210 (93.3%) were reactive in the direct test (smears stained with monoclonal antibodies), whereas culture missed only 5 (sensitivity 97.8%) when stained by the same method. Cultures stained with iodine produced the lowest recovery rate (73.8%), but this rate increased to 80.9% when a second passage was performed. In addition the prevalence of Neisseria gonorrhoeae, Mycoplasma hominis, Ureaplasma urealyticum, Candida albicans and Trichomonas vaginalis was investigated. In patients with non-gonococcal urethritis (no. = 331) and cervicitis (no. = 353), Chlamydia trachomatis was isolated in 32.3% and 12.8% respectively. However, this pathogen could be isolated in only 3 (15.8%) out of 19 patients with epididymitis and 15 (14%) out of 107 patients with adnexitis, although 66.7% and 93.3% respectively had specific IgG antibodies. Specific IgM could by detected with a sandwich ELISA in patients with adnexitis (46.7%), epididymitis (33.3%), cervicitis (22.2%), non-gonococcal urethritis (14%) and in the sexual partners of patients with genital infections (35.7%). The direct specimen test with monoclonal antibodies is the method of choice for the diagnosis of a C. trachomatis infection in patients with urethritis and cervicitis.(ABSTRACT TRUNCATED AT 250 WORDS)

The enigma of non-gonococcal urethritis: role for Bacteroides ureolyticus

Although up to about half the cases of acute non-gonococcal urethritis (NGU) are caused by Chlamydia trachomatis organisms (chlamydiae) and a smaller, ill-defined, proportion probably by Ureaplasma urealyticum organisms (ureaplasmas), the aetiology of all cases is not understood. Clarification of the role of the anaerobe, Bacteroides ureolyticus, was sought in the current study. Seventy five chlamydia negative patients with NGU were treated on a double blind placebo controlled basis with metronidazole. After seven days more of the 35 patients given this drug tended to improve clinically than the 40 given the placebo, but the difference was not significant. Of 23 chlamydia negative but anaerobe positive men, however, 78% (7/9) receiving metronidazole responded clinically, but only 7% (1/14) receiving placebo responded (p less than 0.001). Furthermore, whereas 78% of the anaerobe positive men given metronidazole recovered, only 23% (6/26) of the anaerobe negative men did so (p less than 0.02). No further evidence for the role of ureaplasmas in the aetiology of NGU was obtained, but the data suggest that B ureolyticus organisms, and perhaps other anaerobes, have an important role in a small proportion of cases and that the beneficial effects of metronidazole given on an empirical basis will be confined to anaerobe positive urethritis.

Leucocyte esterase test as rapid screen for non-gonococcal urethritis

The two standard tests for the initial diagnosis of non-gonococcal urethritis (NGU), microscopic examination of gram stained urethral smears and the two glass urine test, have the disadvantage of being insensitive and subjective. The leucocyte esterase test detects enzymes specific to polymorphonuclear leucocytes and can therefore be used as a sensitive indicator of pyuria. This study sought to evaluate its use as a rapid, sensitive, and non-subjective method of screening for NGU. Of the 81 men with urethral symptoms in the study group, 26 had more than 5 polymorphonuclear leucocytes per high power field (x 1000) and all 26 were leucocyte esterase test positive; whereas 55 had fewer than 5 polymorphonuclear leucocytes per high power field, but 29 (53%) of them had a positive leucocyte esterase test result. In addition, 25 patients in the study group yielded Chlamydia trachomatis on culture. Of these 25, 24 (96%) were leucocyte esterase test positive, whereas only 11 (44%) were Gram stain positive. All 40 patients in the control group (without urethral symptoms or signs) were leucocyte esterase test negative. The leucocyte esterase test is thus a rapid, sensitive, and non-subjective screening aid in the diagnosis of NGU.

Effect of vaccination on feline Chlamydia psittaci infection

Experimental ocular infection of specific-pathogen-free cats with the feline pneumonitis strain of Chlamydia psittaci produced an acute, severe conjunctivitis characterized by blepharospasm, conjunctival hyperemia, chemosis, and ocular discharge. Organisms were recovered from the conjunctiva for several weeks, and persistent genital and gastrointestinal infection also resulted from the ocular infection in some cats. Subcutaneous vaccination with live feline pneumonitis C. psittaci 4 weeks before ocular challenge significantly reduced the severity of the conjunctivitis. However, there was no effect on shedding of organisms from the eye or on the transmission of infection to the gastrointestinal and genital tracts. It is suggested that the acute stage of this ocular disease is caused largely by release of pathogenic antigen(s) from chlamydia-infected conjunctival cells, rather than by a direct cytopathic effect of chlamydial replication. Thus, vaccination with whole live organisms reduced the acute disease in experimentally infected cats but did not prevent shedding of the organism. The implications of these findings are discussed.

The in vitro effect of chemical intravaginal contraceptives on Chlamydia trachomatis

The effect of four intravaginal chemical contraceptives on the in vitro growth of Chlamydia trachomatis in cycloheximide-treated McCoy cells was studied. Encare produced significant inhibition, while Koromex had little antichlamydial activity. Both Intercept and Conceptrol had an intermediate effect, reducing chlamydial replication to 60-70% compared to untreated controls. Some variation in these effect against different strains of Chlamydia has been observed. In addition, the antichlamydial properties observed do not seem to be solely mediated by the pH of the preparations or the concentration of nonoxynol-9, the active ingredient in these contraceptives. Thus, intravaginal contraceptives may have a role in decreasing asymptomatic transmission of this organism and possibly as an adjunct to antibiotic therapy in symptomatic patients.

A simple method for the detection of Chlamydia trachomatis infections in general practice

Chlamydial infection is an important cause of genital tract disease in women and is often silent. Collection, storage and transportation of specimens required for culture pose problems which have made studies difficult and diagnosis impractical outside hospitals or sexually transmitted disease clinics.The direct monoclonal antibody test (MicroTrak, Syva) for detecting chlamydiae is comparable with the traditional culture method in sensitivity and specificity. The test requires only the preparation of a smear on a slide, making it convenient for use in general practice. The feasibility of using this procedure in an inner city practice was demonstrated in tests on 188 women who required pelvic examination. Of 169 women from whom valid specimens were obtained 18 (10.7%) were found to have a chlamydial infection. Only three of the infected women were asymptomatic and the organisms were associated particularly with dysuria. The value of the test in comparison with other procedures currently available for detecting chlamydiae is emphasized.

Chlamydia trachomatis and reactive arthritis: the missing link

Reactive inflammatory arthritis is a common sequel to sexually acquired non-gonococcal genital-tract infection. Approximately 50% of cases are associated with Chlamydia trachomatis infection in the genital tract, although conventional cultures of joint material are sterile. Synovium, synovial-fluid cells, or both, from eight patients with sexually acquired reactive arthritis (SARA) and eight with knee effusions associated with other rheumatic diseases were examined by means of a fluorescein-labelled monoclonal antibody to C trachomatis ('Micro Trak'; Syva). Typical chlamydial elementary bodies were seen in joint material from five patients with SARA but in none of the controls. An inclusion-like cluster of elementary bodies was seen in one synovial biopsy sample. All five patients had high titres of serum chlamydial antibody. It is likely that the synovitis of SARA results directly from the presence of chlamydial elementary bodies in the joint.

Coexistent chlamydial infections related to natural history of human papillomavirus lesions in uterine cervix

To assess the role of Chlamydia trachomatis in the development of cervical intraepithelial neoplasia (CIN) and to evaluate possible synergism between chlamydiae and human papillomavirus (HPV) in this process, 418 women who had been prospectively followed up for cervical HPV infections at our clinic since 1981 were tested for chlamydiae. At each visit the patients were examined by colposcopy, and other investigations, such as Papanicolaou (Pap) smears, punch biopsies, urethral, and cervical swabs, were undertaken as indicated. In biopsy specimens the cytopathic changes of HPV, concomitant CIN, and the local immunocompetent cell infiltrates were analysed. The latter were measured and further identified using an alpha naphthyl acetate esterase (ANAE) technique to define B cells, macrophages, and T cells and using monoclonal antibodies to define T cell subsets, NK (natural killer cells), and Langerhans cells. Chlamydial isolation (4.1% in the cervix, and 3.6% in the urethra) did not positively correlate with the degree of cytological atypia in PAP smears or with the degree of CIN lesions associated with HPV. Chlamydial cervicitis did not affect the ANAE definable cell composition of the immunocompetent cell infiltrates in HPV lesions, or that of the immunocompetent cell subsets, including the ratios of T helper to T suppressor cells and the numbers of NK cells. Chlamydial infection did not alter the natural history of HPV lesions, of which 30% regressed, 53% persisted, and 17% progressed during follow up. The present results do not provide evidence to substantiate the hypothesis that chlamydiae and HPV might act synergistically in cervical carcinogenesis, or the view that C trachomatis may be a major aetiological agent of CIN lesions. Chlamydiae and HPV are covariables of sexual behaviour, and their concomitant appearance in sexually promiscuous women is best explained by this fact. As we do not have more direct evidence for the oncogenic potential of C trachomatis (as we have of HPV), it seems reasonable to consider that this agent is not a major cause of CIN, but rather a sexually transmitted agent commonly found in women with CIN because of their promiscuous sexual behaviour.