Chlamydia trachomatis in adolescents: a review

Genital infections caused by Chlamydia trachomatis represent the most prevalent bacterial sexually transmitted disease in the United States. An estimated 3-4 million cases annually necessitate the expenditure of more than $2 billion in health care costs per year. The ramifications of infection with this organism have significant reproductive complications. The objective of this paper is to provide the reader with a review of Chlamydia trachomatis in general with particular focus on those areas that are pertinent to the adolescent population. The authors hereby provide an overview of the clinically pertinent microbiology, epidemiology, risk factors, selective screening protocols, diagnostic methods, clinical manifestations, and sequelae of C. trachomatis.     

Vaginal douching as a risk factor for cervical Chlamydia trachomatis infection

Females with Turner syndrome (TS) are alleged to have increased numbers of melanocytic naevi. Although a high count of acquired melanocytic naevi (AMN) is one of the major risk factors for melanoma, this malignancy has been reported only rarely in patients with TS. The purpose of this study was to explore the effects of environmental and genetic factors on AMN count and density in TS. AMN count and density in 24 patients with TS treated with growth hormone (GH). 24 GH-treated females with GH deficiency (GHD) and 24 normal females were compared in a cross-sectional study. The average AMN density in TS was 50 naevi/m2 as compared with 18 naevi/m2 in the GHD group and 24 naevi/m2 in normal controls (P = 0.001 and P = 0.004, respectively). Duration of GH therapy did not correlate with AMN count (P = 0.44) or AMN density (P = 0.81). The pattern of distribution of naevi between constantly exposed, intermittently exposed and unexposed skin was similar in all groups. Sun exposure was the major factor that affected the regional AMN densities in the control groups, but not in the TS group. The findings of our study indicate that the effects of environmental factors on AMN count and density may vary among genetically different populations. A review of the literature suggested that melanoma is no more prevalent in TS than in the general population.     

Body-image and eating disturbances predict onset of depression among female adolescents: A longitudinal study.

This study examined data from a 4-year school-based longitudinal study (n?=?1,124), to test whether the increase in major depression that occurs among girls during adolescence may be partially explained by the body-image and eating disturbances that emerge after puberty. Elevated body dissatisfaction, dietary restraint, and bulimic symptoms at study entry predicted onset of subsequent depression among initially nondepressed youth in bivariate analyses controlling for initial depressive symptoms. Although the unique effect for body dissatisfaction was not significant in the multivariate model, this set of risk factors was able to fairly accurately foretell which girls would go on to develop major depression. Results were consistent with the assertion that the body-image- and eating-related risk factors that emerge after puberty might contribute to the elevated rates of depression for adolescent girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective screening for Chlamydia trachomatis infection in a primary care population of women

The potency of food chemicals to induce cell aging was evaluated in human diploid fibroblast cells HAIN-55 having a finite replicative potential by using in vitro aging markers, i.e., decreases of maximum proliferative potential (lifespan) of cells, saturation density in monolayer culture (SD), plating efficiency (PE) and mitotic index (MI), and an increase of cells with polyploid karyotypes. By treatment twice with low concentration of genotoxic chemicals aflatoxin B1, allylisothiocyanate or trans-cinnamaldehyde (severe clastogenic flavoring agent; Kasamaki et al., 1982), lifespan (expressed by the number of cumulative cell population doubling (CPD)) of the treated cells was reduced by 8-12 CPDs accompanied by change of the other aging markers. By successive treatment (29 or 25 times) with non-genotoxic chemical aspartame (N-L-aspartyl-L-phenylalanine) or L-canavanine (structural analogue of L-arginine), lifespan of the treated cells was also slightly shortened (by 2-6 CPDs) compared with the untreated control cells. In the process of cell aging, Mitochondrial activity (MTT activity) decreased almost in parallel with the decrease of SD and MI. On the basis of these results, a variety of genotoxic and non-genotoxic chemicals were examined by using MTT activity as the aging marker for their effects on the aging of HAIN-55 cells and bovine artery endothelial cells which also had a finite replicative potential. The results showed that seven genotoxic and nine non-genotoxic chemicals promoted cell aging.     

Chlamydia trachomatis during genital tract infection and in imminent abortion

Chlamydia trachomatis (Ch.t.) is suspected to be a dominant factor in the etiology of genito-urinary tract infectious diseases. The aim of the authors work was the evaluation of the Ch. t. presence in the cervix of women with adnexitis or with the imminent abortion. 300 women were investigated for the Ch.t. detection. The smear taken from the cervical canal was evaluated with 3 methods: direct immunofluorescence assay. Chlamydiazine test and culture. Ch.t. infection was detected in 27% of examined patients. The positive results was observed the more frequently in the patients showing the clinical symptoms of infection (42%) and in the pregnant women with imminent abortion symptoms (26%). The obtained results seem to confirm the pathogenic role of Ch.t. in the genital tract infectious diseases. Authors are postulating them the necessity of the prophylactic Ch.t. detection in the pregnant women.     

Association of genital infection with specific Chlamydia trachomatis serovars and race

Black race is an important risk marker for Chlamydia trachomatis genital infection. To define whether C. trachomatis serovars differ by ethnic distribution, a panel of monoclonal antibodies was used to serotype 934 urethral and 581 cervical isolates from patients attending a sexually transmitted diseases clinic over 2 years. The overall serovar distribution in cervical and urethral infections was comparable, with B class serovars predominating. Significantly higher inclusion counts were observed both in younger women and in nonblacks regardless of serovar. Serovar D was less frequent among blacks at the urethral site (P = .001), while serovar Ia was more frequent in blacks at both sites (urethral, P < .001; cervical, P = .02). These associations remained significant after adjusting for age and number of inclusion-forming units by multivariate analysis. Thus, specific serovars may be associated with particular racial groups; either behavioral or biologic factors could explain these findings.     

Predictors of success within a behavior modification program among male adolescents

48 adolescents placed into a short-term diagnostic group home with a behavior modification program in place were studied. Each subject was administered the Wechsler Intelligence Scale for Children--III and the Screener version of the Wechsler Individual Achievement Test. Assessment data were used to predict the subjects' conduct within the behavioral program as a method of strengthening pretreatment recommendations for planning. Analysis showed that verbal and mathematical skills were significant predictors of the criterion behaviors. These results support the use of cognitive assessment as valid methods of predicting the behavior of teenagers within residential behavior modification programs.     

Predictors of work injuries among employed adolescents.

Predictors of work injuries were studied in a sample of employed adolescents. The 20 predictors comprise 5 general categories of risk factors: demographic, personality, employment, health, and substance use. Data were obtained from a sample of 319 individuals ages 16 to 19. Hierarchical regression analysis revealed that all 5 categories of risk factors were related to job injuries. The significant predictors of work injuries among adolescents were gender, negative affectivity, job tenure, exposure to physical hazards, excessive workloads, job boredom, poor physical health, and on-the-job substance use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synoviocyte-packaged Chlamydia trachomatis induces a chronic aseptic arthritis

The basic mechanisms underlying reactive arthritis and specifically the joint injury that follows intra-articular Chlamydia trachomatis infection have not been defined. The present study addresses this question through the development of an experimental model. Stable cell lines were generated from synoviocytes harvested from the knee joints of Lewis rats. The synoviocytes were cocultivated with C. trachomatis to allow invasion by the microbe and were then transferred by intra-articular injection into the knee joints of Lewis rats. The ensuing arthritis could be subdivided into an early phase (相似文献   

Chlamydia trachomatis utilizes the host cell microtubule network during early events of infection

The host cell cytoskeleton is known to play a vital role in the life cycles of several pathogenic intracellular microorganisms by providing the basis for a successful invasion and by promoting movement of the pathogen once inside the host cell cytoplasm. McCoy cells infected with Chlamydia trachomatis serovars E or L2 revealed, by indirect immunofluorescence microscopy, collocation of microtubules and Chlamydia-containing vesicles during the process of migration from the host cell surface to a perinuclear location. The vast majority of microtubule-associated Chlamydia vesicles also collocated with tyrosine-phosphorylated McCoy cell proteins. After migration, the Chlamydia-containing vesicles were positioned exactly at the centre of the microtubule network, indicating a microtubule-dependent mode of chlamydial redistribution. Inhibition of host cell dynein, a microtubule-dependent motor protein known to be involved in directed vesicle transport along microtubules, was observed to have a pronounced effect on C. trachomatis infectivity. Furthermore, dynein was found to collocate with perinuclear aggregates of C. trachomatis E and L2 but not C. pneumoniae VR-1310, indicating a marked difference in the cytoskeletal requirements for C. trachomatis and C. pneumoniae during early infection events. In support of this view, C. pneumoniae VR-1310 was shown to induce much less tyrosine phosphorylation of HeLa cell proteins during uptake than that seen for C. trachomatis.     

Detection of Chlamydia trachomatis infection by PCR in first voided urines in men

The goal of this study was to evaluate whether the new commercially available PCR-based assay Amplicor C. trachomatis (Roche Molecular Systems) could improve the diagnosis of chlamydial urogenital infections in men, compared with cell culture of C. trachomatis considered as the reference method. A total of 466 men attending the STD clinic were tested by the Amplicor test in urine and by cell culture in urethra. The prevalence of C. trachomatis was 13.7% (64/466) by cell culture and 14.4% (67/466) by the Amplicor test. After resolution of the discrepant results, the sensitivity of culture was 91.4% in male urethral specimens. The resolved sensitivity of the PCR assay was 92.7% in male urine and the specificity was 99.5%. We concluded that this rapid PCR-based assay showed an improvement in quality for diagnosing C. trachomatis infections in men.     

Topological analysis of Chlamydia trachomatis L2 outer membrane protein 2

Using monospecific polyclonal antisera to different parts of Chlamydia trachomatis L2 outer membrane protein 2 (Omp2), we show that the protein is localized at the inner surface of the outer membrane. Omp2 becomes immunoaccessible when Chlamydia elementary bodies are treated with dithiothreitol, and protease digestions indicate that Omp2 has a possible two-domain structure.     

Determinants of reinfection with Chlamydia trachomatis

BACKGROUND AND OBJECTIVES: Epidemiologic studies of chlamydial infections may often miss factors associated with the acquisition of infection. GOAL: To evaluate factors associated with risk for initial and recurrent Chlamydia trachomatis infections. STUDY DESIGN: A retrospective study of patients attending a sexually transmitted disease clinic and, within this retrospective cohort, a nested case-control study. RESULTS: Among initial-negative subjects the crude incidence rate was 11.5 per 1,000 months of follow-up. Among initial-positive subjects, the crude incidence rate was 28 per 1,000 months of follow-up (RR = 1.8, 95% CI: 1.4-2.2). The increase in risk of infection associated with prior infection was independent of age. In the case-control study, a reduced risk of recurrent infection was associated with tubal ligation, hormonal contraception, and barrier contraception. CONCLUSIONS: As well as targeting sexually active adolescents, prevention programs should recommend repeat testing for all women with prior chlamydial infection, irrespective of age. Furthermore, issues related to personal control of health may modify risk for infection.     

Performance of a commercial polymerase chain reaction test for endocervical Chlamydia trachomatis infection in a university hospital population

The rate of survival and causes of mortality in a cohort of 2103 psychiatric patients registered on a psychiatric case register and followed up for 7 years are compared with those of a general population sample (n = 2382) randomly extracted from the municipal census in Valencia (Spain). Using multivariate analysis by Cox regression, patients suffering organic psychoses and those diagnosed with drug abuse or dependency exhibited a greater risk of death than the general population for the total causes of death; no interaction was found between sociodemographic variables and psychiatric pathology. In terms of the causes of death, and controlling for the effect of age and sex, organic psychoses involved a greater risk of death due to cardiovascular and respiratory causes, and a greater risk of non-natural deaths than the general population. Schizophrenia and related conditions, the abuse of alcohol/ other drugs, and neurosis/personality disorders all presented a higher risk of death from liver disease. The major affective disorders involved a greater risk of death due to suicide or accidents. The study concludes with a discussion of the possible explanations of these results.     

A role for interleukin-6 in host defense against murine Chlamydia trachomatis infection

Interleukin-6-deficient (IL-6(-/-)) knockout mice had significantly increased Chlamydia trachomatis levels in lung tissue and increased mortality compared to B6129F2/J controls early after intranasal infection. Gamma interferon production and chlamydia-specific antibody levels were consistent with a decreased but reversible Th1-like response in IL-6(-/-) mice. IL-6 is needed for an optimal early host response to this infection.     

Does Chlamydia trachomatis MoPn enter a microbiologically-inapparent state during experimental infection of the mouse genital tract?

Microbiologically-inapparent chlamydial infection may contribute towards the immunopathogenesis of these diseases. Although morphologically and physiologically aberrant non-cultivable chlamydiae can be induced reversibly in cell culture, evidence for these forms in infections of animals and humans is indirect. A mouse model of salpingitis caused by the mouse pneumonitis biovar of Chlamydia trachomatis (MoPn) was used to determine the existence of non-cultivable organisms in vivo. Following intravaginal inoculation, mice yielded high chlamydial counts for 7-14 dyas, with a decline in culture-positivity by 21-28 days. A significant elevation of IFN gamma production in infected tissues was measured for 21 days and, from 28-70 days, all mice were culture-negative and developed characteristic hydrosalpinges. MoPn was detected by PCR in vaginal swabs of 80% and 69% respectively of culture-negative animals at 21 and 28 days. In a second study, 100%, 63% and 50% of culture-negative genital tissue homogenates were PCR-positive at 21, 28 and 42 days. Immunosuppression with either cyclophosphamide or hydrocortisone failed to regenerate cultivable chlamydiae. Tissues were disrupted by homogenization and inoculated intranasally to MF1 mice which are extremely susceptible to MoPn, but all culture-negative specimens were non-infectious. The significance of the PCR-positive culture-negative specimens requires further investigation, since these may represent a non-cultivable state in the deeper tissues of the mouse genital tract which may be beyond the reach of reactivating triggers.     

Is urine leukocyte esterase test a useful screening method to predict Chlamydia trachomatis infection in women?

We evaluated the use of the leukocyte esterase test (LET) on first-catch urine specimens from women as a screening test to predict infection with Chlamydia trachomatis. For diagnosis, we used Abbott's ligase chain reaction (LCR) on urine specimens and isolation by tissue culture (TC) on cervical brushes. Of 4,053 women attending sexually transmitted disease and family planning clinics, 4.3% (n = 174) were positive by TC and 5.9% (n = 239) were positive by LCR. When LET was compared to TC, the sensitivity, specificity, positive predictive value, and negative predictive value were 54.0, 67.0, 6.8, and 97.0%, respectively. The corresponding performance of LET versus LCR was 53.1, 67.3, 10.1, and 95.8%. Almost half of the laboratory-confirmed chlamydial infections were negative by LET. The low specificity probably reflects multiple causes of pyuria in women and results in a low positive predictive value. LET is neither sensitive nor specific as a predictor of chlamydial infection and cannot be recommended for use as a screening test for C. trachomatis with first-catch urine samples from females from low- or moderate-prevalence populations.     

Genotyping of Portuguese Chlamydia trachomatis urogenital isolates

OBJECTIVE: To determine the prevalence of the different Chlamydia trachomatis genotypes in Portuguese patients. METHODS: Urogenital isolates (n = 240) derived from attenders of various clinics in the Lisbon area were differentiated into genovars by genotyping with restriction fragment length polymorphism (RFLP) analysis of the PCR amplified omp1 gene. RESULTS: Genotype E was the most common for both men (47.9%) and women (43.8%). Genotypes D and F were the second most prevalent for men (11.3%) and genotype H was the second most prevalent for women (19.5%). Genotypes F, G, D, in women and H, G, I, in men, were found in a lower percentage of cases. Genotypes B, Ba, J, K, L1 and L2 were very rarely detected. CONCLUSIONS: With one exception, the overall distribution of Chlamydia trachomatis genotypes in our study is similar to what has been observed in other western countries. The only exception is the unusual prevalence of genotype H among women. The clinical manifestations associated with this and other genotypes were similar.     

The frequency of Chlamydia trachomatis infection in women with intraepithelial neoplasia of the uterine cervix

A case of a rare form of Sanfilippo disease, mucopolysaccharidosis type III D is presented. The cause of the disease is a deficit of N-acetylglycosamine-6-sulfate sulfatase. Differences in clinical course and symptoms with type A and B Sanfilippo disease are shown (later presentation of symptoms, milder course, lack of distinct psychomotor regression and differences in characteristic phenotypic traits, such as facial features, joint contracture, tall height). It is suggested that type III D mucopolysaccharidosis be taken into account in the differentiation of mental retardation syndromes with hyperactivity.     

Development of social-moral reasoning among Kibbutz adolescents: A longitudinal cross-cultural study.

Studied the development of social-moral judgments in 92 Israeli kibbutz adolescents (64 of whom were interviewed longitudinally over 2–9 yrs from ages 12 yrs to 24–25 yrs) from the perspective of L. Kohlberg's theory (1958, 1981) of moral judgment development. The study evaluated the validity of Kohlberg's model and moral judgment interview in a cross-cultural context. In addition, it assessed the cultural uniqueness of social-moral reasoning among kibbutzniks. Findings support the validity of Kohlberg's structural-developmental understanding of moral judgment. Stage change was found to be upward, gradual, and without significant regressions. Analyses showed internal consistency of the stages as operationally defined in the standardized scoring manual. The distribution of stage scores among Ss, overall, was unusually high when compared to the results of parallel studies in the US and Turkey. The most important cultural variation involved the use of Stages 4/5 and 5 (global stage and postconventional stage). While all the stages were present among Ss, not all elements of kibbutz postconventional reasoning were present in Kohlberg's model or scoring manual (e.g., the communal emphasis and collective moral principles). (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)