Predominance of Chlamydia trachomatis Serovars Associated with Urogenital Infections in Females in New Delhi, India

Abstract

Screening for Chlamydia trachomatis was done for 280 endocervical swab samples by PCR specific for endogenous plasmid. Age dependency was seen in symptomatic patients, with a high chlamydial prevalence rate (28%) found in younger women. Genotyping by restriction fragment length polymorphism analysis of omp1 PCR-positive samples showed serovars D, E, and F to be the most prevalent.Chlamydia trachomatis is a major cause of sexually transmitted disease (16). Serovars D to K are chiefly responsible for urogenital infections; of these serovars, E, F, and D account for up to 60 to 70% of these infections (1,5,14,20). Epidemiological studies of C. trachomatis infections in sexual contacts have been few to date, which hampers the study of chlamydial transmission, its route of spread in a population, its virulence factors, and the associated risk factors of C. trachomatis infections (12,19). Compared with immunotyping, the genotyping methods, particularly omp1 are more sensitive and precise in revealing C. trachomatis variants within serovars as well as in potential recombinants among serovars (13,15,18). The present study was undertaken to understand the occurrence of C. trachomatis serovars in the genital tracts of infected women, which will help in devising an effective screening program for routine diagnosis of chlamydial infections, understanding the immunopathogenesis, and developing an effective chlamydial control program.Reference C. trachomatis standard serovars were kindly provided by T. Ossewaarde (National Institute of Public Health and Environment Protection, Bilthoven, The Netherlands). Cervical swabs (n ϭ 280) were obtained from patients (17) attending the gynecology outpatient clinic for various gynecological reasons (abnormal vaginal discharge and pelvic pain) at Safdarjang Hospital, New Delhi, India. Chlamydial DNA was extracted from the clinical specimens by the alkali lysis method (2). The study protocol was approved by the committee responsible for the evaluation of work involving human subjects. Prior consent was obtained in all cases.The clinical samples were first screened by a PCR specific for the human ␤-globin gene. The primers used for the human ␤-globin PCR were P1 (sense, 5Ј ACA CAA CTG TGT TCA CTA GC) and P2 (antisense, 5Ј GAA ACC CAA GAG TCT TCT CT). Samples positive in the ␤-globin PCR were used for C. trachomatis detection by using a plasmid PCR performed as described previously. The plasmid primers P3 (sense, 5ЈGAA CAA ATC GTA TCT CGG) and P4 (antisense, 5ЈGAA ACC AAC TCT ACG TCG) generated a fragment of 517 bp in the C. trachomatis-positive samples. The omp1 gene was amplified by primers selected from the published sequences of the omp1 gene of C. trachomatis (L 2 ) (21). The PCR mixture contained 25 pmol of each of the forward and reverse primers, 200 M concentrations of each of the deoxynucleoside triphosphates (dATP, dTTP, dGTP, and dCTP), 10ϫ PCR buffer (containing 10 mM Tris HCl [pH 8.3], 50 mM KCl, 2.5 mM MgCl 2 , 0.01% gelatin), and 0.1 U of Taq DNA polymerase (Gibco-BRL). PCR w...

Profiling of Human Antibody Responses toChlamydia trachomatisUrogenital Tract Infection Using Microplates Arrayed with 156 Chlamydial Fusion Proteins

“…The GST-CPAF fusion protein was significantly recognized by the pooled positive sera at a dilution of 1:12,500, CT795 and CT089 at 1:2,500, and CT147, CT226, CT694, and various MOMPs at 1:500, demonstrating that CPAF, CT795, and CT089 are more immunodominant than MOMP regardless of the types of MOMPs analyzed. Comparing the nine MOMPs, higher ODs were obtained with MOMPs from serovars B, Ba, D, E, and L2, all of which belong to the C. trachomatis subspecies B complex, suggesting that the 15 patients were predominantly infected with B complex serovars, most likely serovars D and E, in agreement with the epidemiological finding that both serovars D and E are among the most prevalent C. trachomatis serotypes in individuals with sexually transmitted chlamydial infections (3,9,29,30,49). The GSTalone control was not significantly recognized at any dilution.…”

Genotyping of Chlamydia trachomatis from clinical specimens in Taiwan

“…Compared to serotyping, the genotyping methods are more sensitive and specific for C. trachomatis serovar identification (Molano et al, 2004). Many studies have shown the feasibility of deducing the serotypes of C. trachomatis clinical isolates using PCR-based RFLP or sequencing of the amplified omp1 gene that encodes the MOMP, the main surface antigen of C. trachomatis (Ikehata et al, 2000; Lysén et al, 2004;Ngandjio et al, 2003Ngandjio et al, , 2004Singh et al, 2003). The omp1 gene exhibits extensive DNA sequence variation in four discrete regions, termed variable segments (VS1-4) (Stephens et al, 1987;Yuan et al, 1989).…”

Utility of Pooled Urine Specimens for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Men Attending Public Sexually Transmitted Infection Clinics in Mumbai, India, by PCR

“…On the basis of these studies, the prevalence of C. trachomatis among asymptomatic women has consistently been reported as being low. Recently, Singh et al found that 28% of symptomatic young women in New Delhi had C. trachomatis infections when tested with a homebrew PCR (21). Whereas in a population-based study using Amplicor PCR, the prevalence of genital chlamydial infection was reported to be 1.1% in men and women (6).…”