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Non-neutralizing functions of antibodies, including phagocytosis, may play a role in Chlamydia trachomatis (CT) infection, but these functions have not been studied and assays are lacking. We utilized a flow-cytometry-based assay to determine whether serum samples from a well-characterized cohort of CT-infected and naïve control individuals enhanced phagocytosis via Fc-receptor-expressing THP-1 cells, and whether this activity correlated with antibody titers. Fc-receptor-mediated phagocytosis was detected only in CT+ donors. Phagocytosis generally did not correlate well with antibody titer. In addition, we found that complement from both CT+ and negative individuals enhanced phagocytosis of CT into primary neutrophils. These results suggest that anti-CT antibodies can have functions that are not reflected by titer. This method could be used to quantitively measure Fc-receptor-mediated function of anti-CT antibodies or complement activity and could reveal new immune correlates of protection., Competing Interests: N.R.M. and K.N. report receiving research funding under the Merck Investigator Sponsored Program. The other authors report no conflict of interest.

Background: Rectal STI coinfection models enhance the understanding of rectal HIV transmission risk factors., Materials and Methods: Rhesus macaques (n=9) were exposed to one of three rectal Chlamydia trachomatis (CT) challenges: C. trachomatis L 2 (CT-L 2 ); C. trachomatis serovar E (CT-E), followed by CT-L 2 ; or CT-E, treatment/clearance, then CT-L 2 . Infections were monitored by PCR. Weekly blood and rectal secretion/lavage samples were collected for cytokine analyzes and/or epithelial sloughing, occult, and overt blood determinations., Results: Chlamydial infections were successfully established in each animal, with varying degrees of persistence. Mucosal IL-1beta was upregulated in animals consecutively infected with CT-E then CT-L 2 (P=.05). Epithelial sloughing was also significantly increased post-infection in this group (P=.0003)., Conclusions: This study demonstrates successful rectal infection of rhesus macaques with CT-E and CT-L 2 and describes measures of assessing rectal inflammation and pathology. Different infection strategies yield varying inflammatory and pathologic outcomes, providing well-described models for future SIV/SHIV susceptibility studies., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Sexually transmitted infections (STIs) are associated with an increased risk of human immunodeficiency virus (HIV) infection, but their biological effect on HIV susceptibility is not fully understood., Methods: Female pig-tailed macaques inoculated with Chlamydia trachomatis and Trichomonas vaginalis (n = 9) or medium (controls; n = 7) were repeatedly challenged intravaginally with SHIVSF162p3. Virus levels were evaluated by real-time polymerase chain reaction, plasma and genital cytokine levels by Luminex assays, and STI clinical signs by colposcopy., Results: Simian/HIV (SHIV) susceptibility was enhanced in STI-positive macaques (P = .04, by the log-rank test; relative risk, 2.5 [95% confidence interval, 1.1-5.6]). All STI-positive macaques were SHIV infected, whereas 3 controls (43%) remained uninfected. Moreover, relative to STI-negative animals, SHIV infections occurred earlier in the menstrual cycle in STI-positive macaques (P = .01, by the Wilcoxon test). Levels of inflammatory cytokines (interferon γ, interleukin 6, and granulocyte colony-stimulating factor [G-CSF]) were higher in STI-positive macaques during STI inoculation and SHIV exposure periods (P ≤ .05, by the Wilcoxon test)., Conclusions: C. trachomatis and T. vaginalis infection increase the susceptibility to SHIV, likely because of prolonged genital tract inflammation. These novel data demonstrate a biological link between these nonulcerative STIs and the risk of SHIV infection, supporting epidemiological associations of HIV and STIs. This study establishes a macaque model for studies of high-risk HIV transmission and prevention., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: Rectal sexually transmitted infections (STIs) may increase HIV susceptibility in men who have sex with men (MSM), and Chlamydia trachomatis is prevalent among HIV-positive MSM. To study STIs and HIV infection in MSM, we first evaluated whether cynomolgus macaques can sustain both C. trachomatis and SHIVSF162p3 infections., Methods: Four SHIVSF162p3 -positive male cynomolgus macaques were used (n = 3 rectally inoculated with 10(6) IFU; n = 1 control). Systemic and rectal SHIV RNA levels and cytokines were measured by real-time PCR and Luminex assays, respectively., Results: Macaques were successfully Chlamydia infected. Rectal SHIV shedding (P = 0.02 χ(2) ) and levels of G-CSF, IL-1ra, IL-6, IL-8, IFN-γ, and TNF-α (P ≤ 0.01, Mann-Whitney) in rectal secretions increased following infection., Conclusions: These pilot data successfully demonstrate rectal C. trachomatis-SHIV coinfection in cynomolgus macaques and suggest the feasibility of a rectal C. trachomatis model for SHIV susceptibility and biomedical prevention studies in the context of rectal STIs., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Sexually transmitted infections (STIs) are associated with an increased risk of HIV infection. To model the interaction between STIs and HIV infection, we evaluated the capacity of the pigtail macaque model to sustain triple infection with Trichomonas vaginalis, Chlamydia trachomatis, and SHIV(SF162P3)., Methods: Seven SHIV(SF162P3) -infected pigtail macaques were inoculated with T. vaginalis only (n = 2), C. trachomatis only (n = 1), both T. vaginalis and C. trachomatis (n = 2), or control media (no STI; n = 2). Infections were confirmed by culture and/or nucleic acid testing. Genital mucosa was visualized by colposcopy., Results: Characteristic gynecologic signs were observed for both STIs, but not in control animals. Manifestations were most prominent at days 7-10 post-infection. STIs persisted between 4 and 6 weeks and were cleared with antibiotics., Conclusions: These pilot studies demonstrate the first successful STI-SHIV triple infection of pigtail macaques, with clinical presentation of genital STI symptoms similar to those observed in humans., (Published 2011. This article is a U.S. Government work and is in the public domain in the USA.)

Three gel formulations (1%, 3%, and 5% [wt/wt]) of SPL7013, a dendrimer known to have antiviral (anti-human immunodeficiency virus and anti-herpes simplex virus) activities, completed a range of preclinical tests in the pigtailed macaque models for vaginally and rectally applied topical microbicide safety assessments. The vaginal safety profile of the 3% SPL7013 gel formulation was equal to that of the 1% formulation but was superior to that of the 5% formulation. The 3% SPL7013 gel was further evaluated for rectal safety and for antichlamydial efficacy with cervical challenge with Chlamydia trachomatis. This first-generation dendrimer-based product was shown to be safe to the vaginal and rectal microenvironments with repeated daily use. However, a single intravaginal application of the 3% (wt/wt) SPL7013 gel did not provide protection from the acquisition of cervical chlamydial infection.

Background: The nonhuman primate model allows for safety and efficacy testing of topical microbicide products., Goal: The goal of this study was to evaluate the safety and efficacy of vaginal and rectal applications of BufferGel (ReProtect, Inc.)., Study Design: The safety of repeated product applications was evaluated by microflora, pH, vaginal colposcopy, and rectal lavage. To test efficacy in preventing chlamydia, infection was documented by culture and nucleic acid amplification tests., Results: Repeated vaginal or rectal applications of BufferGel were not associated with significant changes in microflora. BufferGel use had a transient acidifying effect on vaginal and rectal pH. Colposcopic observations remained relatively normal in all test animals. A slightly increased incidence of epithelial desquamation was noted after rectal product use compared with the control group. BufferGel did not prevent cervical or rectal chlamydial infection., Conclusion: BufferGel has an acceptable safety profile after repeated vaginal and rectal use, but does not prevent chlamydial infection in the macaque models.

Background: A topical microbicide should protect against acquisition of sexually transmitted infection during both vaginal and rectal intercourse. The rectal microflora of the Macaca nemestrina (pig-tailed macaque) and humans were examined, as well as the histopathology of rectal tissues. In a subset of macaques, a human rectal isolate of Chlamydia trachomatis was inoculated into the rectum to establish rectal chlamydial infection., Goal: To evaluate the comparability of the pig-tailed macaque rectal model with humans., Study Design: Rectal swabs were collected for microbiologic analysis to characterize normal microflora in pig-tailed macaques and humans. Subsequently, 10 macaques received a rectal inoculation with C trachomatis, serovar D, prepared from a clinical rectal isolate., Results: The rectal microflora of pig-tailed macaques (n = 80) were found to be comparable with the rectal flora of humans (n = 40). The prevalence of Lactobacillus in the rectum was higher in the macaques than in humans. Coliform and Enterococcus were decreased in the macaques, as compared with those of humans. In 9 of 10 macaques, rectal chlamydial infection was confirmed by culture or ligase chain reaction on days 2, 7, and 14 after inoculation. The test results were positive for rectal chlamydial infection by ligase chain reaction only for the remaining animal on day 14 after inoculation., Conclusions: The findings demonstrate that the rectal environment of the pig-tailed macaque is a useful model for further evaluation of newly developed topical microbicides for rectal use. Furthermore, such products can be evaluated for protection against rectal chlamydial infection in this model.

Problem: The pathogenesis of long-term sequelae in Chlamydia trachomatis infection is poorly understood. While serology indicates previous chlamydial infection, culture studies are frequently negative. We wanted to know whether in chronic cases the bacterium is absent or persists in a dormant state where it evades detection., Methods of Study: Using immunoperoxidase (IP) staining and in situ hybridization (ISH), we examined tissues of culture-negative subjects. Ovarian biopsy specimens from 19 culture-negative women with pelvic adhesions and/or tubal infertility were analyzed by both methods. Samples of prostates from 10 culture-negative men undergoing prostatectomy for benign hypertrophy, two sets of semen samples from culture-negative sexual partners of 28 women with PID and/or bacterial vaginosis (BV), and ten endometrium-tube sample-pairs from ectopic pregnancies (EPs) were examined by IP only., Results: Seven of the nineteen ovarian specimens tested positive for Chlamydia antigen or deoxyribonucleic acid (DNA) (36%). Of the 10 hypertrophic prostates examined, 4 (40%) were positive. Of the 28 semen samples examined, 10 (35%) tested positive. Tissue samples of 3 cases of EP were positive by IP., Conclusions: 1. C. trachomatis antigen and nucleic acid can be frequently demonstrated in asymptomatic, culture-negative men and women with chronic infection. 2. Chlamydia antigens may have an etiologic role in benign prostate hypertrophy and EP. 3. Antigenic material may be sexually transmissible. 4. IP and ISH identify temporarily inactive bacteria that may continue to act as immunostimulants and potentially reactivate as Chlamydia infection.

A primate model of chlamydial pelvic inflammatory disease was used to characterize serum antibody responses to the 60 kDa chlamydial heat shock protein (CHSP60). Forty monkeys were infected in the fallopian tubes with Chlamydia trachomatis and then were treated. Twenty-three (58%) monkeys developed antibodies against CHSP60, of whom 6 (15%) had CHSP60 responses that persisted throughout the study and 17 (42.5%) had a transient response. A persistent CHSP60 antibody response was correlated with being culture- or ligase chain reaction-positive in the fallopian tubes (P=.004), but not in the cervix pretreatment, and with being tubal-positive posttreatment (P=. 02). Compared with tubal-negative monkeys, tubal-positive monkeys had more intense CHSP60 responses (P=.006) that lasted longer (P=. 002). Among CHSP60 responders, an OD>0.5 was correlated with more severe salpingeal pathology before treatment (P=.04). CHSP60 antibody response may be useful as a marker of persistent chlamydial infection in the fallopian tubes.

Background and Objectives: An estimated 4 million new cases of chlamydial infection occur each year. This experiment assessed the effects of a vaginally applied gel formulation of 0.25% chlorhexidine gluconate on chlamydial infection and on the vaginal ecosystem., Study Design: Twelve monkeys were treated with a single application of 0.25% chlorhexidine gluconate. These animals were assessed for changes in vaginal flora before and at 30 minutes, 1 day, and 2 days postapplication by microbiologic analysis. Cervical and vaginal tissues were assessed by colposcopy at each time point. Five monkeys received a single application of 0.25% chlorhexidine gluconate gel followed (30 minutes) by a cervical inoculation with Chlamydia trachomatis. Four monkeys were inoculated with Chlamydia only. Cervicovaginal tissues were assessed via modified colposcopy, vaginal swabs were collected for assessment of vaginal flora, and cervical swabs were collected for detection of Chlamydia (culture/ligase chain reaction) at baseline and days 1, 2, and 7 postinoculation., Results: Changes in vaginal flora were minimal in all monkeys. Application of 0.25% chlorhexidine gluconate did not affect adversely vaginal colonization by lactobacilli. All chlamydial infection control monkeys were infected, whereas none of the five monkeys pretreated with chlorhexidine gluconate were positive for C. trachomatis by culture or ligase chain reaction. Colposcopic observations remained largely unchanged in all groups., Conclusions: A 0.25% chlorhexidine gluconate gel was protective against chlamydial infection in all animals tested, had no adverse effect on the vaginal flora, and had minimal effect on cervicovaginal tissues after a single application.

Chlamydia trachomatis-associated female infertility and ectopic pregnancy are caused by postinflammatory fibrosis and scarring of the upper genital tract. Scarring of the upper genital tract is associated with multiple infectious episodes with C. trachomatis. To study the immune response that occurs with multiple infections of C. trachomatis in the female upper genital tract, a Macaca nemestrina model was used. Subcutaneous pockets containing autologous salpingeal tissue implants were inoculated three times with C. trachomatis. The inflammation after three inoculations was associated with a mononuclear infiltrate dominated by CD8 T-cell lymphocytes. Perforin mRNA was induced in infected pockets, demonstrating that activated cytolytic lymphocytes were present in the lesions. Fibrosis, as evidenced by fibroblast proliferation and connective tissue deposition, was observed by the third infection. Cytokine mRNAs induced by repeated chlamydial infection included gamma interferon, interleukin-2 (IL-2), IL-6, and IL-10 mRNAs, but IL-4 mRNA was not induced. Nearly identical findings were found in macaque fallopian tubes infected in situ repeatedly with C. trachomatis, validating the subcutaneous pocket model of chlamydial salpingitis. However, it was not possible to evaluate if there was an induction of perforin mRNA in infected salpingeal tubes in situ, because there was a high basal level of perforin mRNA in these tissues. These results suggest that repeated chlamydial infection of the female upper genital tract leads to CD8 T-cell predominance, a Th1-like cytokine milieu, and these inflammatory changes are associated with progression to fibrosis associated with female infertility.

The macaque model of chlamydial pelvic inflammatory disease (PID) demonstrates individual variability in the time of onset of intrapelvic adhesions. Some animals develop adhesions rapidly, within 2 weeks after a single tubal inoculation with Chlamydia trachomatis, while in others, adhesions are not observed until 2 weeks after a second tubal inoculation. To test whether this variability correlates with major histocompatibility complex (MHC) class I haplotype, we used macaque alloantisera and mouse anti-HLA monoclonal antibodies to determine the MHC class I haplotypes of 44 C. trachomatis-infected macaques (Macaca nemestrina). Macaques developing gross tubal adhesions after the first chlamydial inoculation were classified as susceptible (n = 29), while those not developing adhesions until after the second chlamydial inoculation were classified as relatively resistant (n = 15), to adhesion formation. Three antibody specificities correlated with susceptibility (odds ratio [OR] 5.2, P < 0.01; OR 6.1 and 4.3, P < 0.05), and two correlated with relative resistance to adhesions (OR 0.1, P < 0.05; OR 0.2, P < 0.01). Because several of these antibodies are cross-reactive, as many as five different MHC class I alleles (three increasing and two decreasing ORs) or as few as two different MHC class I alleles (one increasing and one decreasing OR) could be correlated with risk of adhesion formation. We conclude that in macaques, susceptibility or relative resistance to rapid formation of tubal adhesions is correlated with expression of MHC class I alleles, consistent with reports of MHC class I restriction of chlamydial immunopathology in humans.

To evaluate the effects of antimicrobial and antiinflammatory drugs on oviductal pathology in chronic chlamydial upper genital tract infection, the fallopian tubes of 40 female Macaca nemestrina were inoculated with Chlamydia trachomatis and randomly assigned to treatment with doxycycline (n = 10), doxycycline plus ibuprofen (n = 10), doxycycline plus triamcinolone (n = 10), or placebo (n = 10). Before therapy, all animals were positive for culture or ligase chain reaction (or both), and laparoscopy demonstrated the presence of upper genital tract pathology. After therapy, cervical cultures remained positive in 5 animals given placebo versus 0 given doxycycline alone (P = .03), 0 given doxycycline plus ibuprofen (P = .03), and 1 given doxycycline plus triamcinolone (P = .14). At hysterectomy, neither gross nor histologic pathology was affected by any of the treatment regimens, but immunocytochemistry and in situ hybridization evidence of persistent tubal infection was significantly more frequent among animals given placebo or doxycycline plus antiinflammatory agents than among those given doxycycline alone.

Background and Objectives: Nonoxynol-9, an intravaginal microbicide, is chlamydiacidal in vitro but also cytotoxic. This study examines the effects of nonoxynol-9 in vivo, using a pigtail macaque model of chlamydial cervicitis., Goals: To establish a minimum infectious dose of Chlamydia trachomatis in the macaque, and to observe the effects of a single dose of nonoxynol-9 on efficiency of chlamydial infection, vaginal microflora, and cervicovaginal irritation., Study Design: The effects of 4% nonoxynol-9, C. trachomatis (5,000 or 10,000 IFU) or both nonoxynol-9 application and chlamydial infection were studied in 17 macaques., Results: Following a single application of nonoxynol-9, chlamydial infection was prevented in 4 of 6 monkeys infected with 10,000 IFU; there was a transient decrease in anaerobic gram-negative rods (P < 0.05) and Peptostreptococci (P > 0.05), but no change in Lactobacillus. Mild cervicovaginal irritation was observed in the monkeys., Conclusions: A single dose of nonoxynol-9 causes minimal vaginal flora and epithelial irritation, and may be useful for prevention of chlamydial infection.

Chlamydia trachomatis infects the upper genital tract of millions of women, causing infertility and pelvic inflammatory disease, yet the inflammatory response to C. trachomatis infection is poorly understood. The cytokine response and the phenotype of infiltrating lymphocytes during C trachomatis infection of fimbria and ampulla autografts in subcutaneous pockets in Macaca nemestrina were characterized. About two-thirds of the infiltrating lymphocytes were CD8 T cells, with the remainder being CD4 T cells and B cells. Interleukin (IL)-2, IL-6, IL-10, interferon-gamma (IFN-gamma), and perforin mRNA were produced by the infiltrating cells, but IL-4 mRNA was absent. The presence of CD8 T cells and perforin mRNA suggest that activated cytolytic T cells are present. The presence of IL-2 and IFN-gamma mRNA and the absence of IL-4 mRNA suggest that Th1-type cytokines predominate during the acute phase of C. trachomatis infection of the upper genital tract.

To further investigate a proposed relationship between Chlamydia pneumoniae and coronary heart disease, coronary atheromas were collected from patients undergoing percutaneous atherectomy. Fifty-eight atheroma specimens were examined by culture and polymerase chain reaction (PCR) and 22 by electron microscopy. All were negative for C. pneumoniae, except a single specimen that was PCR-positive. These results differ from studies in other populations, in which this organism was identified by nonculture methods within coronary atheromas obtained at autopsy. Anti-C. pneumoniae antibody titers from 65 of the patients were compared with those of 28 asymptomatic controls. IgG titers were higher in controls than in patients. There is no evidence that C. pneumoniae exists within atheromas in this study population, nor does seroprevalence correlate with the presence of coronary disease in these patients.

Chlamydia pneumoniae (TWAR), a common cause of acute respiratory disease in humans, has recently been associated with coronary and aortic atherosclerosis. In this study, we evaluated rabbit models of chlamydial infection to investigate the pathogenesis of C. pneumoniae infection. New Zealand White rabbits were inoculated intranasally and intratracheally with C. pneumoniae, strain AR-39, and primary and repeated infection were assessed. After a single inoculation, lung pathology was characterized by a moderate self-resolving interstitial pneumonia with bronchiolitis of 21 days in duration. Chlamydial DNA was detected by polymerase chain reaction (PCR) intermittently in the upper respiratory tract and lung tissue through day 21 postinoculation, spleen tissue at day 14, and peripheral blood mononuclear cells at days 3 and 21. After repeated inoculations, chlamydial DNA was detected by PCR in the upper respiratory tract and lung tissue through day 42. Lung lesions consisted of multifocal interstitial mononuclear cell aggregates that persisted up to day 42. Watanabe heritable hyperlipidemic rabbits were less susceptible to C. pneumoniae infection. After multiple inoculations of Watanabe rabbits, C. pneumoniae was detected by PCR and/or immunocytochemistry until day 21. In conclusion, C. pneumoniae induced a moderate respiratory infection in these rabbit models.

Background and Objectives: Although it has been hypothesized that repeated infections with Chlamydia trachomatis result in an increased potential for the development of infertility, it is not know whether repeated chlamydial infection by the vaginal route will result in an increased incidence of upper tract pathology or enhanced pathology., Goal of This Study: To determine whether guinea pigs given two infections with the chlamydial agent of guinea pig inclusion conjunctivitis would experience an increased incidence of pathologic changes compared with animals having only a single infection., Study Design: Guinea pigs previously infected with guinea pig inclusion conjunctivitis were challenged with a fresh intravaginal inoculum 73-77 days after the primary infection. Oviducts were examined either nine or 30 to 37 days after the challenge infection for pathologic changes and compared with control unchallenged animals 75 to 85 days after a primary infection., Results: A significant increase in the number of animals with oviducts demonstrating marked tubal dilatation was observed in the challenged animals 30 to 37 days after the challenge infection. There was no association of increased antibody titer and chlamydial Hsp60 with the presence of tubal dilatation., Conclusion: These data strongly indicate that repeated infection via the natural vaginal route does increase the risk of tubal damage.

The ultrastructural lung pathology of Swiss Webster mice on days 2, 4, 7, 11, 15, and 21 after intranasal inoculation of Chlamydia pneumoniae AR-39 is described. The inflammatory infiltrate was predominantly polymorphonuclear leukocytes on day 2. By day 7, mononuclear cells were most prominent in the infiltrate. On day 2, chlamydial inclusions were found frequently in the bronchial ciliated epithelial cells and less frequently in the interstitial cells that appeared to be macrophages. Free particles of all developmental forms of the chlamydial microorganism were found in the bronchial lumen and alveolar space. These particles were likely organisms released from infected cells. Inclusions as well as free particles were difficult to find after day 4. These ultrastructural observations suggest an immunopathologic basis for the acute phase of the disease process.

Objective: Biopsy tissues from women with postinfectious tubal infertility were studied for the presence of Chlamydia trachomatis., Study Design: Tubal biopsy specimens from 25 women with postinfectious tubal infertility undergoing laparoscopy for repair of fallopian tubes were evaluated by culture, in situ hybridization. Immunocytochemistry, and transmission electron microscopy for the presence of Chlamydia trachomatis. Serum was also tested for Chlamydia trachomatis antibodies., Results: Chlamydia trachomatis was detected in postinfectious tubal biopsy specimens in three of 25 patients by culture, 12 of 24 by in situ hybridization, 15 of 22 by immunoperoxidase stain, and two of 10 by transmission electron microscopy. Serum antibody against Chlamydia trachomatis was detected in 15 of 21 patients., Conclusion: Chlamydia trachomatis deoxyribonucleic acid or antigens were detected at a high percentage (19/24 women) in the biopsy tissues of the fimbrial and peritubal adhesions by in situ hybridization or immunoperoxidase stain, suggesting a persistent infection in these women even after antibiotic treatment.

The role of delayed hypersensitivity in the pathogenesis of Chlamydia t trachomatis salpingitis was studied in the monkey "pocket" model. Pigtailed monkeys (Macaca nemestrina) were sensitized by inoculation of live C. trachomatis organisms (E/UW-5/Cx) into subcutaneous pockets containing salpingeal autotransplants. At 21 days, affinity-purified recombinant C. trachomatis heat-shock protein (rhsp60) was injected into pockets either previously sensitized with C. trachomatis or not sensitized in the same monkey. Delayed-type hypersensitivity reaction was observed, characterized by mononuclear cell infiltration with peak reaction at 48 h. Injection of rhsp60 into the pockets of a naive animal did not induce inflammation. This study showed that C. trachomatis infection in monkeys induced delayed hypersensitivity, which is mediated by hsp60. Histologic findings of the salpinx were consistent with delayed hypersensitivity reaction observed in ocular C. trachomatis infection, further suggesting a similar pathogenesis for both salpingitis and trachoma.

Background and Objectives: The effects of oral contraceptive use on chlamydial infections and ensuing PID are not well understood. In this study, the effects of oral contraceptives on the clinical course of acute chlamydial salpingitis were investigated., Study Design: Monkeys (n = 4) in which salpingeal auto-transplants had been established were given oral contraceptive pills consisting of a combination of estrogen and progesterone (Norlestrin 1/50, Parke-Davis, Ann Arbor, MI). After one complete cycle of hormone treatment, monkeys were inoculated with C. trachomatis serovar E in the subcutaneous salpingeal pockets while under continuous hormone treatment. Inoculated pockets were biopsied serially for isolation of organisms and histopathological evaluation. Two monkeys not given oral contraceptives were studied in parallel., Results: The duration of infection as evidenced by recovery of organisms was not appreciably different between the treated and untreated monkeys. Chlamydia could be recovered from pocket tissues through day 10 post-infection in control and treated animals, and on day 14 post-infection in one of two control animals. Thereafter all isolation became negative. The inflammatory infiltrate consisted primarily of mononuclear cells (50-100 cells per 40 x field)., Conclusions: Our results indicate that administration of oral contraceptives did not affect the duration of shedding of organisms nor the histopathology of acute chlamydial infection of the reproductive tract.

Background and Objectives: The role of spermatozoa in carrying microorganisms from the cervix to the fallopian tubes and promoting infection was examined in eight pig-tailed macaques., Goal of This Study: The aim of this study was to determine whether spermatozoa play a role in the transport of Chlamydia trachomatis into the upper reproductive tract and in the pathogenesis of chlamydial salpingitis., Study Design: Five monkeys were inoculated with Chlamydia trachomatis in the cervix and mated, and three other monkeys were infected in the cervix but not mated., Results: Culture positive results were obtained for cervical samples from all animals. After cervical inoculation, no mated animals and one unmated animal had positive culture results for samples from the fallopian tubes. After mating, no spermatozoa examined in samples taken from the upper tract or cul de sac had elementary bodies (EBs) on their surfaces, and only one sample obtained from the cervix showed C. trachomatis attached to the spermatozoa, as determined by fluorescent antibody (FA) staining. Two of the mated monkeys became pregnant; one spontaneously aborted late in gestation, and the other delivered a normal female infant. The fallopian tubes of all eight monkeys were challenged directly with serovar D and examined for evidence of salpingitis. Repeat laparoscopy was performed to monitor the inflammatory response. Tubal specimens for isolation and polymerase chain reaction (PCR) were obtained. Hysterectomies were performed between 3 and 4 weeks after tubal inoculation. Histopathologic examination of the fallopian tubes revealed widespread inflammation consisting of focal collections of lymphocytes and plasma cells in the submucosa. Peritubal adhesions were observed in four of five mated monkeys and in two of three unmated monkeys., Conclusion: This study failed to confirm that spermatozoa play a role in the pathogenesis of C. trachomatis infection.

Several quinolones have been shown to have antichlamydial activity in vitro and in vivo. We evaluated the effects of the quinolone CI-960 (Parke-Davis) on primary or repeated chlamydial infection in the monkey salpinx pocket model. The antichlamydial effect was evaluated in the tissues, and we tested for the presence of the organism by culture, immunocytochemical stains, in situ hybridization, and histopathology. An intravenous dosage of 5 mg/kg of body weight produced therapeutic concentrations in plasma (blood sera and pocket fluids) of at least 0.25 microgram/ml at 2 h posttreatment. In monkeys with primary infections, treatment was started 2 days after inoculation and was continued for 7 days. After CI-960 treatment, all animals became culture negative. One of two control animals was culture positive through day 10 postinoculation. In monkeys with repeated infections five inoculations were given within 2 weeks. A 7-day intravenous treatment was started on day 2 postinoculation following the last inoculation. Isolation of Chlamydia trachomatis prior to treatment was positive intermittently for all monkeys. After treatment, isolation of C. trachomatis was negative for all monkeys. In monkeys with both primary and repeated infections, no significant differences were noted in the inflammatory responses in the tissues of treated and untreated animals. All tissues tested were positive by immunoperoxidase staining and/or in situ hybridization. After CI-960 therapy, C. trachomatis organisms were no longer recoverable by cell culture. The persistent finding of chlamydial DNA throughout the observation periods following drug therapy may indicate the presence of dead organisms or viable organisms in an unculturable state.

Seven pig-tailed macaques were inoculated in the cervix with Chlamydia trachomatis. Cervical infection resulted in all animals. After spontaneous cessation of cervical shedding of C. trachomatis, repeated inoculation either failed to produce infection, or resulted in infection of shorter duration with lower inclusion counts. Thus, cervical infection may lead to protective local immunity in pig-tailed macaques.

The effects of repeated cervical infections followed by a single direct tubal inoculation with Chlamydia trachomatis, serovars D and F, were examined in 11 pig-tailed macaques to test the hypothesis that tubal inoculation after cervical priming causes a more severe disease than primary tubal inoculation alone. Animals were cervically inoculated between two and five times. Fallopian tubes were inoculated with serovar D or F 1 week after the last cervical challenge. Three control monkeys received only one direct tubal inoculation without previous cervical inoculation. Infection was confirmed by isolating the microorganism from the endocervix in 13 of 14 monkeys and from the endosalpinx in four only after the tubal inoculation. Antibody was detected in post-infection sera of all 14. Tubal edema occurred in seven of 11 animals after the first cervical inoculation, and uterine erythema occurred in 11 of 11 after the second cervical inoculation. Peritubal adhesions were induced before the tubal inoculation in zero of seven given three or fewer cervical inoculations and four of four given five cervical inoculations (P less than .01). After direct tubal inoculation, peritubal adhesions became more prominent, and the 11 hysterectomy specimens showed plasma cell endometritis in nine and salpingitis in nine. Two control monkeys developed minor adhesions, the other none. One tube in two of three controls showed mild plasma cell infiltrates, whereas no evidence of endometritis was observed in controls. Histopathology in these monkeys was characteristic of chlamydial endometritis and salpingitis. However, the pathogenesis of these changes is uncertain because C trachomatis was not isolated from the endosalpinx after cervical inoculations alone.

Time-lapse cinematography was used to study the growth cycle of Chlamydia trachomatis in primary cell cultures of human amnion. Twelve preterm and twelve term placentas were obtained within 8 h of delivery, and epithelial cells were dissociated from the amniotic membranes by trypsinization and grown in Rose chambers. The epithelial nature of the cultured cells was documented by morphology and by immunofluorescence staining for cytoskeletal proteins, which matched the staining of intact amnion. With regular feedings, uninfected cultures remained healthy for up to 30 days. Confluent cultures (7 to 10 days) were infected with a genital strain (E/UW-5/CX) of C. trachomatis at 10(5) infectious units per chamber. Infections were done in culture medium without cycloheximide, which is often used to induce susceptibility of the cells. Between 66 and 90% of the cells were infected. Intracytoplasmic inclusions were visible by 18 h post infection (p.i.) and grew larger as the organisms inside multiplied. By 72 h p.i., the inclusions occupied the entire cytoplasm of the host cells. Further growth of the inclusions overdistended and ruptured the host cells on days 3 to 7. Cells not infected by the original inoculum became infected on day 5 or 6 p.i. by the chlamydial particles released from the ruptured cells. No amniotic cell was ever observed to survive the infection. The data presented support the hypothesis that amniotic epithelium is susceptible to infection and damage by C. trachomatis. This culture system provided detailed and dynamic observations of chlamydial infection under conditions more nearly physiologic than previously reported.

This study was conducted to determine the efficacy of the male mouse as a model for epididymitis caused by human genital serovar E, Chlamydia trachomatis. C. trachomatis was reisolated from all tissues removed on Days 3, 5, and 7 post inoculation (pi). Although some infected epididymides removed on Days 10, 14, and 21 pi were positive, control tissues remained negative. Histopathology of tissues showed a heavy, mixed inflammatory infiltrate consisting of polymorphonuclear cells and lymphocytes. Serum antibody to C. trachomatis was detected in the infected mice only (titer greater than or equal to 1:32). Chlamydial inclusions and individual elementary bodies were confirmed by immunofluorescent and immunoperoxidase staining up to Day 7 pi. These data show that the male mouse is susceptible to C. trachomatis infection and is appropriate for studies dealing with the effect of C. trachomatis on male fertility.

Experimental acute salpingitis was produced in four pig-tailed monkeys, Macaca nemestrina, by intratubal inoculation with Chlamydia trachomatis (serotypes E or F). The organisms were reisolated from both the endosalpinx and endocervix as early as 1 week after the original inoculation. Endosalpinx cellular responses to the infection were examined by light, transmission, and scanning electron microscopy. A moderate lymphocyte infiltration was detected in the submucosa on day 7. By days 14 and 21 the lymphocytic infiltration was heavy and extended into both the submucosa and the mucosa; the infiltration subsided by day 35. Epithelial cell degeneration occurred in close approximation to lymphocytes, suggesting the immunologic basis of tissue destruction. Scanning electron microscopy revealed extensive deciliation and increased plasmalemmal alterations of nonciliated cells. The presence of C. trachomatis in frozen and deparaffinized tissues was demonstrated by immunofluorescence and immunoperoxidase staining with monoclonal antibody to C. trachomatis. Only secretory cells contained chlamydial inclusions. A humoral immune response to C. trachomatis was demonstrated by microimmunofluorescence. No histologic or immunologic evidence of infection was present in two control monkeys inoculated with HeLa cell material. The histopathologic and immunologic findings of this study establish the pig-tailed monkey as a useful model for further studies of the pathogenesis and pathophysiology of chlamydial salpingitis.

Acute infection with Chlamydia trachomatis serotype E was established in monkey fallopian tube fimbriae by subcutaneous implantation. Depending upon monkey species, from eight to 20 implants could be established in each animal. Animals were given estrogen before percutaneous inoculation of the autografts with Chlamydia. Acute inflammatory changes were found in homografts examined in the first week after infection, with chronic inflammatory changes noted thereafter. Chlamydial inclusions were detected within fimbrial epithelial cells up to seven days postinoculation by fluorescent-antibody staining and immunoperoxidase staining with C. trachomatis-specific monoclonal antibody. Organisms were recovered from autografts up to five days after infection. Analysis of serum antibody by microimmunofluorescence revealed that serotype E-specific antibody of both IgM and IgG classes was produced after infection. We conclude that subcutaneously implanted fallopian tube autografts may provide a useful primate model for kinetic studies of chlamydial infection and immunity.

The murine biovar (mouse pneumonitis) of Chlamydia trachomatis was inoculated into the left oviduct of female Swiss Webster mice to establish acute salpingitis. Chlamydial inclusions were observed in secretory epithelial cells by both transmission electron microscopy and light microscopy using immunoperoxidase staining of deparaffinized sections. By days 5-8 after infection, a mixed polymorphonuclear and mononuclear cellular infiltrate was observed in the submucosa and mucosa. Epithelial cell deterioration occurred in the endosalpinx in areas of heavy mononuclear cellular infiltration. During the acute phase of the disease a cellular infiltrate consisting mainly of T cells was identified by staining frozen tissue sections with monoclonal antibodies to mouse lymphocyte antigens. Occasionally B lymphocytes were observed. Widespread deciliation of the mucosa was observed by scanning electron microscopy. No histopathologic or immunopathologic responses were observed in the control oviducts. These observations suggest an immunologic basis for the structural abnormalities seen in the infected oviducts.

Four Macaca nemestrina monkeys were inoculated in the conjunctiva with Chlamydia trachomatis (strain E) at 6 weeks of age. A fifth monkey was inoculated with HeLa cell materials only. Ten weeks later, all monkeys were reinoculated with either strain E or strain C. All inoculated monkeys were susceptible to infection with C. trachomatis as documented by fluorescent antibody staining of smears and reisolation of the organism from conjunctival and nasopharyngeal swab specimens. Rectal and vaginal swab specimens remained negative throughout the study. Three of four inoculated animals responded with IgM titers reaching a peak of 1:16 (M#3) and 1:32 (M#1, M#4) 2 weeks after the primary inoculation. IgG appeared in all inoculated animals and titers rose to peak levels of 1:64 (M#2), 1:128 (M#1, M#3), and 1:256 (M#4). Histopathology documented a dramatic difference in immunological response following secondary inoculation. Primary inoculation elicited a typical inflammatory response characterized by moderate stromal infiltration of polymorphonuclear and mononuclear leukocytes. Plasma cells appeared by week 3 postinoculation (pi). Following a secondary inoculation, classic follicle formation was evident by 1 week pi. Mononuclear markers identified a germinal center composed of B cells and a T cell cap. Epithelial thinning near the cap of the follicle was accompanied by a complete loss of goblet cells. This model may be useful for studying the immunopathology of infant chlamydial infections.

Experimental salpingitis was studied by the introduction of Chlamydia trachomatis, immunotype D, directly into the oviducts of New Zealand White rabbits. Some rabbits were rechallenged with immunotype F to elicit a second infection. Both experiments produced self-limited acute salpingitis. Light microscopy (LM) and transmission electron microscopy (TEM) showed an extensive polymorphonuclear leukocytic infiltration in the submucosa and mucosa. Scanning electron microscopy (SEM) revealed various alterations of the endosalpingeal surface, including deciliation and flattening of the epithelial cells. These morphologic changes were more pronounced following rechallenge. High and long-lasting serum antibody titers were observed in those rabbits receiving intratubal inoculation of live infectious organisms; no response was evident when inactivated organisms were used. These results indicate that the rabbit is useful in the study of the effects of infection on oviductal function.

Experimental infection of fallopian tubes was produced in four sexually mature pig-tailed monkeys (Macaca nemestrina) by intratubal inoculation with serovar E or F Chlamydia trachomatis. Infection was confirmed by reisolation of the organism from both the endosalpinx and the endocervix. An antibody response to the infecting strain of C. trachomatis was demonstrated in monkey sera and in cervical secretions by the microimmunofluorescence test. A cellular immune response to C. trachomatis was shown by the in vitro lymphocyte transformation assay. Histopathologic examination of the endosalpinx following infection showed epithelial degeneration and deciliation of ciliated cells. Lymphocytic infiltration into both submucosa and mucosa was present at day 7 and approximated areas of epithelial cell degeneration. Two control monkeys remained unresponsive throughout the study. These results indicate that the pig-tailed macaque should be a suitable model for further studies of the pathogenesis of, immune responses to, and therapy for acute C. trachomatis salpingitis.

The effects of repeated infections with Chlamydia trachomatis, serovars F, D, and J, were examined in pig-tailed macaques. The fallopian tubes of three experimental monkeys were inoculated at the middle of the menstrual cycle on three consecutive months. Monkey 1 received homologous F; monkey 2 received heterologous F, D, and J; and monkey 3 received homologous inoculations in the right and heterologous inoculations in the left fallopian tubes. One control monkey (4) received repeated inoculations of HeLa cell materials only and remained normal throughout the experiment. Infection was confirmed by isolating the microorganism from both the endosalpinx and endocervix. Antibody to the infecting strains was demonstrated in sera, tears, and cervical secretions by using microimmunofluorescence. Mild chronic salpingitis developed in monkeys 1 and 3, and chronic follicular salpingitis developed in monkey 2. Peritubal and periadnexal scarring and endosalpingeal adhesion formation were produced after reinfection. The right fallopian tube of monkey 3 was distally obstructed (confirmed by hysterosalpingography). Systemic complications, including perihepatitis and conjunctivitis, were also documented in these monkeys. We conclude that repeated infections produced extensive tubal scarring, chronic salpingitis, and distal tubal obstruction, findings not apparent in primary infection.

The subcutaneous pocket model of salpingeal, endometrial, and conjunctival autografts for studying Chlamydia trachomatis infection in monkeys is described. Portions of the salpinx that were transplanted included fimbria, ampulla, and isthmus. The model is an extension of the original model which consists of either salpingeal fimbria or conjunctive autografts. Transplantation of the ampulla portion of the Fallopian tube enabled us to increase the number of pockets or test sites. Salpingeal and conjunctival autografts could be established during a single surgery. In addition, it is possible to autotransplant endometrium and provoke endometritis. The autografts were shown to be susceptible to C. trachomatis infection. Preliminary rechallenge experiments showed infection of the subcutaneous transplants may induce immunity, indicating the model may be used for immunity and vaccine studies. Simultaneous transplantation of different parts of the oviduct, endometrium, and conjunctive should expand the usefulness of the subcutaneous model in other studies on mixed infections or immune responses to infection.

Monkeys with subcutaneously autotransplanted salpingeal fimbrial tissues were subjected to primary and repeated infections with Chlamydia trachomatis. The inflammatory response after primary inoculation was characterized by infiltration with polymorphonuclear leucocytes in the acute phase and mononuclear cells in the chronic phase. However, the inflammatory response after repeated infections was dominated by a mononuclear cell infiltration with a conspicuous absence of the initial phase of polymorphonuclear leucocyte infiltration. The remarkable findings of repeated infections were plasma cell infiltration, lymphoid follicle formation, and increased fibroblast activity resulting in extensive fibrosis. These findings are similar to those described for monkeys inoculated directly into the oviducts with C. trachomatis and support our original hypothesis that, after chlamydial infection, the tissue damage is provoked by immune-mediated mechanisms.