E M Peterson

Factors influencing the induction of infertility in a mouse model of Chlamydia trachomatis ascending genital tract infection

In women, infections due to Chlamydia trachomatis frequently result in long-term sequelae including chronic abdominal pain, ectopic pregnancy and infertility. In an attempt to characterise the pathogenesis of the infection, female C3H (H-2k) mice were inoculated intravaginally with different doses of C. trachomatis and then mated with proven male breeder mice. The inoculated mice developed a broad spectrum of clinical manifestations ranging from infertility to asymptomatic shedding. The dose inducing infertility in 50% of the mice was c. 10(5) inclusion-forming units of C. trachomatis. In another group of mice sampled at intervals after intravaginal inoculation, C. trachomatis was recovered from the upper genital tract starting at 24 h after infection. A higher percentage of animals infected during the luteal phase of the oestrous cycle had positive cultures from the middle and upper genital tract than when mice were inoculated during the follicular phase. These results indicate that rapid therapeutic intervention is required to avoid the sequelae resulting from C. trachomatis genital infection, and suggest that hormonal factors play a role in the pathogenesis of the disease.

Mapping of a surface-exposed B-cell epitope to the variable sequent 3 of the major outer-membrane protein of Chlamydia trachomatis

A B-cell epitope, AEFPLDIT, was located to the variable sequent 3 of the major outer-membrane protein (MOMP) using the monoclonal antibody L3-1, raised to the Chlamydia trachomatis serovar L3 MOMP. By Western blot and inclusion immunofluorescence assay the monoclonal antibody recognized all the C complex and C-related complex serovars of C. trachomatis, except serovar C. Dot-blot and ELISA data using native elementary bodies indicated that the epitope was surface exposed. The monoclonal antibody, at concentrations of 10 and 100 micrograms per 10(7) chlamydial inclusion-forming units, was able to neutralize the infectivity of chlamydia in an in vivo assay but did not neutralize chlamydia in vitro or in a mouse toxicity assay. A peptide corresponding to the variable sequent 3 has previously been shown to also elicit a T-cell response; thus, careful consideration should be given to inclusion of this region of the major outer-membrane protein in a subunit vaccine.

The Effect of Media and Temperature on the Storage of Chlamydia Trachomatis

Four media, Eagles minimal essential medium with 10% fetal bovine serum (MEM/FBS), tryptic soy broth (TSB), 2-SP, and 4-SP, were compared for their ability to maintain the viability of Chlamydia trachomatis at 4 degrees C, -20 degrees C, -70 degrees C, and -176 degrees C (liquid nitrogen) over a 1-week period. 2-SP maintained viability of C. trachomatis to the greatest extent for all of the time intervals and temperatures examined. Therefore, in an attempt to further stabilize the viability of C. trachomatis, 2-SP was supplemented with various concentrations of bovine serum albumin (BSA) or fetal bovine serum (FBS). For the times and temperatures examined, 2-SP supplemented with 20% or 40% FBS or 5% BSA preserved infectivity to a greater extent than unsupplemented 2-SP. In some supplemented media, up to 65% of the infectivity was preserved after one week of storage at -176 degrees C, whereas only 0-3% of infectivity remained when stored in unsupplemented media at -20 degrees C and 4 degrees C, respectively. Therefore, supplementation of 2-SP with FBS or BSA can prolong the survival of chlamydia, which is critical in the transportation and storage of clinical specimens. In addition, storage for prolonged periods of time should be at -70 degrees C or lower temperatures.