Genotyping of Chlamydia trachomatis from clinical specimens in Taiwan

Abstract

This study was conducted to determine the prevalence and distribution of Chlamydia trachomatis genotypes in Taiwan. Urine and endocervical-swab samples were collected from two hospitals located in northern and southern Taiwan. The genotypes of a total of 145 samples positive for C. trachomatis were analysed by sequencing the omp1 gene and this was successful in 102 samples. Nine different C. trachomatis genotypes were identified. Genotype E was the most prevalent (22 %), followed by D and Da (19 %), F (16 %), J (15 %), K (11 %), G (11 %), H (6 %) and Ba (2 %). There was a geographical difference in the prevalence of genotype H (P<0?018) between northern and southern Taiwan. Sequence mutation analysis by BLAST searching against GenBank reference sequences identified 12 genetic variants from a total of 102 omp1 gene sequences. INTRODUCTIONChlamydia trachomatis infection is the most prevalent sexually transmitted bacterial disease. It is estimated that 89 million cases occur annually worldwide (Gaydos et al., 2004). Because in 50 % of men and 80 % of women infected individuals are asymptomatic, the actual number of reported cases represents only a fraction of the infected population (Gaydos et al., 2004). Currently 19 human serovars and related variants (A, B/Ba, C, D/Da, E, F, G, Ga, H, I/Ia, J, K, L1, L2, L2a and L3) have been identified by using polyclonal and monoclonal antibodies against the major outer-membrane protein (MOMP) (Grayston & Wang, 1975;Ngandjio et al., 2004;Pedersen et al., 2000;Suchland & Stamm, 1991;Wang et al., 1985;Yuan et al., 1989). Based on the pathogenic potential, serovars A, B, Ba and C are commonly associated with trachoma. Serovars D to K are commonly associated with urogenital infections, such as urethritis, epididymitis, cervicitis, salpingitis, pelvic inflammatory disease and ectopic pregnancy; serovars L1 to L3 are commonly associated with lymphogranuloma venereum (Yuan et al., 1989). Furthermore, suggestions have been made that the infections with C. trachomatis serovars G, I and D are associated with cervical squamous cell carcinoma, and chronic infections with serotype K in women have been recognized as a cause of infertility (Anttila et al., 2001;Koskela et al., 2000;Marrazzo & Stamm, 1998;Morre et al., 2000).Serological typing methods have a limitation in that newly emerging types may be missed and culturing of clinical isolate is usually required (Eckert et al., 2000;Suchland & Stamm, 1991). 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...

Genotyping and prevalence of Chlamydia trachomatis infection among women in Belém, Pará, northern Brazil

“…In both studies, genotypes E, D and F were identified most frequently in samples from subjects with urogenital infections of C. trachomatis, respectively comprising 83.3% and 71.8%, of the genotypes found. These results accord with the findings of studies in other countries (such as Argentina, Costa Rica, Taiwan, Iran and Hungary), in which the same three genotypes were found to appear most frequently in urogenital cases of C. trachomatis [6,7,23]. In the present study, genotype F was the most frequent, followed by genotypes D and J.…”

“…Currently, 19 serovars and related variants (A, B/Ba, C, D/Da, E, F, G/Ga, H, I/Ia, J, K, L1, L2, L2a and L3) of C. trachomatis have been identified by using polyclonal and monoclonal antibodies against the major outer membrane protein (MOMP) [5,6]. Serovars A, B and C have usually been associated with trachoma, whereas D through K have tended to correlate with urogenital infections.…”

Distribution Study ofChlamydia trachomatisSerovars among High-Risk Women in China Performed Using PCR-Restriction Fragment Length Polymorphism Genotyping

“…To the best of our knowledge, this is one of the first studies on genotype distribution of C. trachomatis in mainland China (10) and a study with a relative large sample size compared with previous studies ( Table 2). The failure rate (5.6%) of nested omp1 PCR in our study was comparable to those reported in many previous studies (5, 11) but much lower than in other studies (10).…”

“…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, which encodes the MOMP (8,10,15). This technology has provided a valuable and sensitive means for molecular epidemiological analysis to identify high-risk groups and track sexual networks (6,7).…”

Chlamydia trachomatis Serovar Distribution and Neisseria gonorrhoeae Coinfection in Male Patients with Urethritis in Greece

“…The most common serovar detected worldwide is E (up to 22 to 49% of cases) followed by serovars F and D (17 to 22% and 9 to 19%, respectively), while other serovars are less frequently identified (1,10,12,15,16,17).…”