Comparison of two panels of monoclonal antibodies for determination of Chlamydia trachomatis serovars

Abstract

A panel of monoclonal antibodies was developed for serovar typing of clinical isolates of Chlamydia trachomatis. The panel could distinguish all 15 established serovars from one another, although the hybridomas of the panel were developed by fusions of myeloma cells and spleen cells from mice immunized with antigen derived from the urogenital serovars D to L3. The typing assay was based on a dot enzyme immunoassay, and the monoclonal antibodies that were included in the panel reacted strongly in this assay. A collection of 289 clinical isolates from The Netherlands was typed. The observed serovar frequency distribution was 51 isolates of serovar D (17.6%), 103 isolates of serovar E (35.6%), 62 isolates of serovar F (21.5%), 28 isolates of serovar G (9.9%), 14 isolates of serovar H (4.8%), 2 isolates of serovar I' (0.7%), 20 isolates of serovar J (6.9%), and 9 isolates of serovar K (3.1%). These results were confirmed by typing these isolates with a panel of monoclonal antibodies purchased from the Washington Research Foundation, Seattle. No strain variation was observed within serovar D with both panels. However, restriction fragment length polymorphism analysis of the gene encoding the major outer membrane protein showed that 32 isolates were similar to the prototype D and 17 were similar to the variant D-. The two others showed a new restriction pattern. Our panel of monoclonal antibodies contained one monoclonal antibody that divided the serovar G isolates into two groups. This differentiation was confirmed by restriction fragment length polymorphism analysis, confining this difference to a known sequence variation in variable domain IV. These data support the subdivision of serovar G into serovars G (prototype strain UW-57) and Ga (prototype strain IOL-238).

Serotyping and Genotyping of Genital Chlamydia trachomatis Isolates Reveal Variants of Serovars Ba, G, and J as Confirmed by omp1 Nucleotide Sequence Analysis

“…Serotyping. The clinical isolates (enriched by passage in cell culture) were serotyped by using MAbs in a dot enzyme immunoassay as described in detail elsewhere (16). Briefly, sheets of grided nitrocellulose (Schleicher and Schuell, Dassel, Germany) were cut into pieces of 8 by 12 cm 2 , fixed on an inert support (such as used X-ray film), and spotted with antigens.…”

“…Chlamydia trachomatis is the most common bacterial sexually transmitted disease (STD) and is currently classified into 15 serovars: A, B, Ba (AP-2), C, D, E, F, G, H, I, J, K, L1, L2, and L3. This classification is based on immunoepitope analysis of the major outer membrane protein (MOMP) with polyclonal and monoclonal antibodies (MAbs) (11,16). The MOMP is the immunodominant antigen of C. trachomatis and contains four variable domains (VDs) that are flanked and interspaced by five constant domains (CDs).…”

“…Three of the variable domains (VD1, VD2, and VD4) are surface exposed and contain antigenic epitopes (21). Differences in reactivities with MAbs and polyclonal antibodies have led to the identification of a large number of C. trachomatis serovariants: Ba (UW113, J104, J160, TW439, U/CT77), Da (TW448, MT199), D Ϫ (NL32 6, TB39, MT157, RB205), D* (MTS2, ICD033), Ga (IOL238), Ia (NL1540, MT165), I Ϫ (MT518, MT741, MT1196), and L2a (UW396) (3,4,12,16,23). Characterization of the nucleotide sequences of the omp1 genes of these serovariants (except Ga) demonstrates that almost all nucleotide sequence differences result in amino acid substitutions (2,3).…”

New methods in diagnostic and epidemiological research of Chlamydia trachomatis infections: the tide is turning molecular

“…Using the reaction of clinical isolates with antisera 15 serovars ean be distinguished [61]. The application of monoclonal antibody technology further refines this classification by detecting serovar variants [62,63]. However, the availability of antisera and monoclonal antibodies is limited.…”

Urogenital Chlamydia trachomatis Serovars in Men and Women with a Symptomatic or Asymptomatic Infection: an Association with Clinical Manifestations?

“…Serovars A, B, Ba, and C infect mainly the conjunctiva; serovars D, Da, E, F, G, Ga, H, I, Ia, J, and K are predominantly isolated from the urogenital tract; and serovars L1, L2, L2a, and L3 can be found in the inguinal lymph nodes. Conventional serotyping is performed after C. trachomatis culture using polyclonal and monoclonal antibodies against the major outer membrane protein of C. trachomatis (1,24,25). The recently developed method of direct PCRbased restriction fragment length polymorphism (RFLP) analysis (genotyping of the omp1 gene, which encodes the MOMP) of cervical and urethral swabs has partially replaced the laborious and less sensitive serotyping technique (8,14,21,27,28).…”