Chlamydia trachomatis genital infections in tahiti

The rate ofChlamydia trachomatis infection was determined in three populations in Tahiti by means of a direct immunofluorescence test performed in specimens, tissue culture and detection of chlamydial antibody in serum specimens using a single-serotype indirect immunofluorescence test.Chlamydia trachomatis was recovered in 53 % of 53 bar girls, 24 % of 75 women attending a public maternity clinic for routine care, and 37 % of 71 men attending a sexually transmitted disease clinic with acute or subacute urethritis. The presence of chlamydial antibody in a high proportion of the groups studied confirmed the high frequency of chlamydial infections (62.3 %, 66.6 % and 83.1 % respectively).Neisseria gonorrhoeae infection was often associated with chlamydial infection in both bar girls and men with urethritis (11.4 % and 18.3 % respectively). With regard to clinical manifestations, 58.3 % (7/12) of bar girls and 23.2 % (10/43) women at the maternity clinic without clinical complaints were found to beChlamydia trachomatis-positive. The presence ofChlamydia trachomatis in these asymptomatic persons highlights their important role in spread of this organism in Tahiti. The findings indicate that routine testing forChlamydia trachomatis is warranted in patients attending the sexually transmitted disease and public maternity clinics in Tahiti.     

Prevalence of Chlamydia trachomatis in genital samples from Abidjan]

A study of direct genital swabs achieved in Abidjan, on 116 men and 131 women consulting for urogenital complaints, has revealed that the men show a prevalence of 28.4% Chlamydia trachomatis, and of 18.1% Neisseria gonorrhoeae. Concerning the women the prevalence of the same germs are 13.7% for Chlamydia trachomatis, and 4.6% for Neisseria gonorrhoeae. These results show the importance of Chlamydia trachomatis as a sexually transmitted disease in Abidjan (C?te-d'Ivoire). No differences were observed according to age in the two groups.     

Evaluation and comparison of tests to diagnose Chlamydia trachomatis genital infections

Infection with Chlamydia trachomatis results in intracytoplasmic inclusions and the generation of infectious elementary bodies (EBs). These can be detected by various procedures. Staining of epithelial cells with vital dyes was first used to detect inclusions, but is insensitive. Thus, Papanicolaou-stained cervical smears cannot be recommended. The advent of the ability to grow chlamydiae in cultured cells over 30 years ago had a major impact on chlamydial research and on detection. However, this procedure is probably <70% sensitive for cervical infection and less for urethral infection in men and is now practised infrequently following the advent of other, mostly less laborious and often equally, or more sensitive detection systems. Thus, staining a smear with a specific fluorescent monoclonal antibody to detect EBs is simple and the direct fluorescent antibody tests became a commercial proposition in the early to mid-1980s. Nevertheless, although highly sensitive and specific in competent hands, technical expertise is crucial and even the most experienced may be unable to read a large number of stained smears on slides quickly. In view of this, it is understandable that enzyme-linked immunosorbent assays (ELISAs) gained popularity from the mid-1980s onwards, for they are not very labour intensive and their reading is neither subjective nor tedious. Unfortunately, these aspects outweighed the fact that the ELISAs lack sensitivity, some being very insensitive. The situation has been rescued, however, by the advent in the early 1990s of methods that amplify chlamydial DNA, making it easily detectable by relatively simple procedures. The polymerase chain reaction is such a method and has high specificity and sensitivity, although commercial development has so far not met the high standard expected of it in terms of sensitivity. The ligase chain reaction does not invoke such criticism, and high values for both sensitivity and specificity may be expected, even on urine samples. This augers well for diagnosing an infected individual patient and for effective screening programmes. Antibody tests have no place in a screening programme and are of debatable value in diagnosis.      

Interrelationship of Chlamydia trachomatis and other pathogens in the female genital tract.

The isolation of Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and Candida albicans in the female genital tract was studied in 1323 patients attending a venereal disease clinic. Disruption of the cell monolayers use for the isolation of C. trachomatis was significantly associated with the presence of T. vaginalis; this effect was markedly reduced by the addition of vancomycin to gentamicin and amphotericin B in the transport and growth media. The only significant positive association was the more frequent isolation of C. trachomatis in the presence of N. gonorrhoeae. There was a negative association between N. gonorrhoeae and C. albicans and between T. vaginalis and C. albicans, the fungus being isolated significantly less frequently when these microorganisms were present.     

Entry of genital Chlamydia trachomatis into polarized human epithelial cells.

To study the initial invasion process(es) of genital chlamydiae, a model system consisting of hormonally maintained primary cultures of human endometrial gland epithelial cells (HEGEC), grown in a polarized orientation on collagen-coated filters, was utilized. After Chlamydia trachomatis inoculation of the apical surface of polarized HEGEC, chlamydiae were readily visualized, by transmission electron microscopy, in coated pits and coated vesicles. This was true for HEGEC maintained in physiologic concentrations of estrogen (proliferative phase) and of estrogen plus progesterone (secretory phase), despite the finding that association of chlamydiae with secretory-phase HEGEC is significantly reduced (P = 0.025; A.S. Maslow, C.H. Davis, J. Choong, and P.B. Wyrick, Am. J. Obstet. Gynecol. 159:1006-1014, 1988). In contrast, chlamydiae were rarely observed in the clathrin-associated structures if the HEGEC were cultured on plastic surfaces. The same pattern of coated pit versus noncoated pit entry was reproducible in HeLa cells. The quantity of coated pits associated with isolated membrane sheets derived from HeLa cells, grown on poly-L-lysine-coated cover slips in medium containing the female hormones, was not significantly different as monitored by radiolabeling studies and by laser scanning microscopy. These data suggest that culture conditions which mimic in vivo cellular organization may enhance entry into coated pits for some obligate intracellular pathogens.     

Experimental infection of the marmoset genital tract with Chlamydia trachomatis.

A strain of Chlamydia trachomatis isolated in McCoy cells from the urethra of a patient suffering from non-gonococcal urethritis was inoculated into the vagina of 8 female marmosets. Chlamydiae were isolated repeatedly for 10-42 days from the lower genital tract of 7 of the marmosets. Six of the infected animals developed an acute inflammatory reaction in the genital tract and chlamydial inclusions in epithelial cells were seen in smears from 2 of them. In addition, each of 6 infected marmosets examined developed humoral antibodies to C. trachomatis. In contrast, 3 control animals inoculated intravaginally with chlamydia-free McCoy cells showed no evidence of chlamydial infection. Since the marmoset is small and easily bred in captivity, it should provide a useful model for studying the mechanisms of chlamydial pathogenicity.     

Chlamydia trachomatis causing neonatal conjunctivitis in a tertiary care center

Chlamydia trachomatis is considered a major aetiological agent of conjunctivitis in newborns. The objective of the present study was to determine the aetiology of neonatal conjunctivitis and clinico-epidemiological correlates of chlamydial ophthalmia neonatorum. Fifty-eight newborns with signs and symptoms of conjunctivitis were studied. Conjunctival specimens were subjected to Gram staining, routine bacteriological culture, culture for Neisseria gonorrhoeae and direct fluorescent antibody (DFA) staining for diagnosis of C. trachomatis infection. C. trachomatis was detected in 18 (31%) neonates. Findings suggest that since C. trachomatis is the most common cause of neonatal conjunctivitis, routine screening and treatment of genital C. trachomatis infection in pregnant women and early diagnosis and treatment of neonatal Chlamydial conjunctivitis may be considered for its prevention and control.     

Detection of Chlamydia trachomatis in genital specimens by the Chlamydiazyme test.

Cotton swabs were used to collect two specimens each from 416 patients (206 males, 210 females) attending a sexually transmitted disease clinic. The first swab was transported in Specimen Storage Reagent and extracted in Specimen Dilution Buffer for enzyme immunoassay by Chlamydiazyme (Abbott Laboratories); the second swab was extracted into 2SP and inoculated into McCoy cell cultures. In the first phase of the study (215 patients: 111 males, 114 females) enzyme immunoassay results were positive (optical density greater than or equal to 0.1) in 30 of 35 instances in which Chlamydia trachomatis was isolated (sensitivity, 86%). Of 18 false-positive enzyme immunoassay results, 15 (83%) were cervical swabs (specificity, 90%). In a phase II study, using a modified Chlamydiazyme kit, 201 patients were tested (95 males, 106 females). Of 41 chlamydial isolates, 8 were not detected by the Chlamydiazyme test (sensitivity, 81%). Only three positive Chlamydiazyme test results could not be confirmed by culture (specificity, 98%). Overall, Chlamydiazyme assay provided a rapid (4 h), sensitive, and specific assay for the detection of chlamydial antigens.     

Chlamydia trachomatis genital tract infection of antibody-deficient gene knockout mice.

The importance of antibody-mediated immunity in primary and secondary Chlamydia trachomatis genital tract infections was examined by using a definitive model of B-cell deficiency, the microMT/microMT gene knockout mouse. Vaginally infected B-cell-deficient microMT/microMT mice developed a self-limiting primary infection that was indistinguishable from infection of control C57BL/6 mice. Sera and vaginal secretions from infected mice were analyzed for anti-Chlamydia antibodies. C57BL/6 mice produced high-titered serum anti-Chlamydia immunoglobulin G2a (IgG2a), IgG2b, and IgA antibodies, and vaginal washes contained predominately anti-Chlamydia IgA. Serum and vaginal washes from infected B-cell-deficient mice were negative for anti-Chlamydia antibody. T-cell proliferation and delayed-type hypersensitivity assays were used as measures of Chlamydia-specific cell-mediated immunity and were found to be comparable for C57BL/6 and B-cell-deficient mice. Seventy days following primary infection, mice were rechallenged to assess acquired immunity. B-cell-deficient mice which lack anti-Chlamydia antibodies were more susceptible to reinfection than immunocompetent C57BL/6 mice. However, acquired immune resistance was evident in both strains of mice and characterized by decreased shedding of chlamydiae and an infection of shorter duration. Thus, this study demonstrates that cell-mediated immune responses alone were capable of resolving chlamydial infection; however, in the absence of specific antibody, mice were more susceptible to reinfection. Therefore, these data suggest that both humoral and cell-mediated immune responses were important mediators of immune protection in this model, though cell-mediated immune responses appear to play a more dominant role.     

Polymorphisms in the Chlamydia trachomatis cytotoxin locus associated with ocular and genital isolates

Chlamydia trachomatis is a strict human pathogen producing infections that cause medically important chronic inflammatory diseases, such as blinding trachoma and tubal factor infertility. Isolates exist as serotypes that fall into distinct biologic and pathological groups corresponding to differences in infection tissue tropism and invasion properties. Paradoxically, genome sequencing of several diverse strains has revealed a remarkable level of genomic synteny, suggesting that minor genetic differences determine the pathogen host- and tissue-specific infection characteristics. To better understand the genetic basis of chlamydial pathobiologic diversity, we performed comparative DNA-DNA microarray genomic hybridizations with all 15 C. trachomatis serovariants. We found there are few major genetic differences among the 15 serovars. An exception was the cytotoxin locus located in the plasticity zone, a region that exhibited significant polymorphisms among serovars. We therefore sequenced this region from all 15 serovars. The cytotoxin gene was interrupted by extensive mutations and deletions among the different serovars; however, three basic open reading frame motifs were discovered that correlated with noninvasive oculotropic, urogenitotropic, and invasive serovars. Of interest, only noninvasive genitotropic serovars possessed an intact N-terminal portion of the putative toxin gene. This region contains the UDP-glucose binding domain and the glycosyltransferase domain required for enzymatic activity of the clostridial toxin homologs, suggesting a role in urogenital infection or pathogenesis.     

Chlamydia trachomatis reactive T lymphocytes from upper genital tract tissue specimens

Chlamydia trachomatis infection is associated with pelvic inflammatory disease (PID) and tubal factor infertility (TFI). We investigated the role of C. trachomatis as a target antigen of endometrial and salpingeal tissue lymphocytes derived from PID and TFI patients. Antigen specificity of the tissue originated T lymphocyte lines (TLL) was tested against C. trachomatis elementary bodies and chlamydial heat shock protein 60 (CHSP60). C. trachomatis antigen stimulated proliferation in two out of eight endometrial TLL derived from PID patients and three out of four TLL derived from TFI patients. All (n = 4) TLL derived from the salpingeal specimens responded to CHSP60 compared with only one out of 12 TLL derived from the endometrial specimens. In-vivo expression of interferon-gamma (IFN-gamma) mRNA revealed that it was present in nine of 13 specimens obtained from PID patients. The dominant activity of type-1 T lymphocytes was confirmed by the in-vitro production of IFN-gamma (median 1007 pg/ml) from all (n = 5) C. trachomatis specific TLL while IL-5 secretion was lower (median 779 pg/ml). In conclusion, C. trachomatis reactive TLL were established from in-vivo activated lymphocytes from the upper genital tract tissue of PID and TFI patients. The reactivity of the salpingeal TLL to CHSP60 provided further evidence that immunoreactivity to CHSP60 is a predominant response in patients with tubal damage.     

Cultural method for large-scale screening for Chlamydia trachomatis genital infection.

Idoxuridine-treated McCoy cells grown as monolayers in 96 well microplates provide a convenient method for the isolation of Chlamydia trachomatis. Staining of infected monolayers with periodic acid-Schiff reagent (PAS) allows easy recognition of C trachomatis inclusions without the need for dark-ground microscopy. By this method 384 clinical specimens can be examined concurrently. It is sufficiently sensitive to form the basis of a chlamydial culture service for patients attending Sexually Transmitted Diseases (STD) Clinics.     

Multicenter evaluation of the AntigEnz Chlamydia enzyme immunoassay for diagnosis of Chlamydia trachomatis genital infection.

To evaluate the AntigEnz Chlamydia enzyme immunoassay (EIA) (Baxter/Bartels, Issaquah, Wash.), we studied 320 men and 1,209 women attending clinics for sexually transmitted diseases in Baltimore, San Francisco, and Seattle. At examination, two separate swabs were obtained from each patient, one for chlamydial culture and one for EIA. Cervical samples were collected from women, and urethral samples were collected from men. The prevalence of chlamydial infection by culture was 9% in Baltimore (n = 532), 11% in Seattle (n = 500), and 9% in San Francisco (n = 497). To resolve specimens with discrepant culture and EIA results, the EIA transport buffer was centrifuged and the resuspended pellet was stained by direct immunofluorescence to determine whether elementary bodies were present. Overall sensitivity of the AntigEnz Chlamydia assay compared with culture was 87% in men and 86% in women, and overall specificities were 94 and 97%, respectively. Differences between centers were seen, with sensitivities ranging from 76% among men and 79% among women in Seattle to 100% among men and 95% among women in Baltimore. With a true positive considered to be either a culture-positive or an EIA- and direct immunofluorescence-positive specimen, the revised sensitivity was 91% in men and 88% in women. Overall revised specificity was 99% in both men and women. We conclude that in this high-prevalence population, the sensitivity and specificity of this assay compare favorably with those of other noncultural antigen detection tests for the diagnosis of chlamydial genital infection.     

Detection of Chlamydia trachomatis in genital specimens by the Microtrak direct specimen test

The conventional cell culture method for detection of Chlamydia trachomatis requires two to six days and is technically difficult to perform. The authors evaluated a new, relatively simple, non-culture method (MicroTrak, Syva Co., Palo Alto, CA) that requires less than one hour to complete. Two hundred fifty-one cervical and 209 male urethral specimens from three Richmond health clinics were read by direct immunofluorescence staining and compared with cell culture technics using iodine staining. Patient specimens were applied directly onto microscope slides (8 mm well) and stained with a fluorescein-labeled monoclonal antibody. Slides were examined for 10-15 minutes at X1,000 using an AO epifluorescent microscope and were considered positive if five or more typical elementary bodies were seen. The sensitivity, specificity, positive and negative predictive values for the direct smear were 89%, 97%, 85%, and 98% for males, and 93%, 96%, 85%, and 98% for females, respectively. The rapid direct specimen test appears to be a satisfactory method for detecting chlamydia in male and female genital specimens.     

拟诊为淋病患者中泌尿生殖道沙眼衣原体基因分型及序列分析

目的 了解深圳市拟诊为淋病患者中泌尿生殖道沙眼衣原体的合并感染情况及其基因型分布和序列变异特点.方法 采集401例拟诊为淋病患者的泌尿生殖道分泌物样本,应用Roche Amplicor全自动核酸检测系统对样本进行淋球菌和沙眼衣原体双检,提取DNA,应用巢式聚合酶链反应(nested-PGR)扩增沙眼衣原体主要外膜蛋白基因(omp1)中的VS1～VS2片段,并对其进行序列测定,所获得的序列利用Mega4.0软件与标准参考株进行比对,分析确定其基因型及序列变异情况.结果 401例拟诊为淋病患者中淋球菌的感染率为82.3%(330/401),沙眼衣原体的感染率为24.2%(97/401),淋球菌和沙眼衣原体的合并感染率为21.7%(87/401).97份沙眼衣原体阳性样本中获得73份沙眼衣原体基因片段序列,共检出8个基因型,分别为E型(27.4%)、G/Ga型(23.3%)、D/Da型(16.4%)、F型(13.7%)、J型(11.0%)、H型(5.5%)、B和K型(各1.4%).序列分析发现3例(4.1%)菌株发生错义突变,分别为D/Da型、E型、G/Ga型;F型、H型、J型和K型序列虽多见碱基突变,但均为同义突变.结论淋病患者合并感染沙眼衣原体的比例较高,且泌尿生殖道沙眼衣原体的基因型以E、G/Ga、D/Da和F型为主.序列分析可以为泌尿生殖道沙眼衣原体的分子流行病学研究提供依据.     

Detection of Chlamydia trachomatis in clinical material 1989-1990]

Examination of 276 smears and scrapings from the uterine cervix of women before delivery and during the puerperium revealed in 28.0% positive findings. Perinatal infection was confirmed by the presence of Chlamydia trachomatis in 35.5% neonates with conjunctivitis and 27.3% positive smears from the nasopharynx. The authors used the direct immunofluorescence method. For immunofluorescent staining they used Chlamyset of Orion Co., Finland.