An in vivo activity of antibiotics against Chlamydia trachomatis (serovar L2) was examined by using ddy demale mice, 6 weeks of age. Serovar L2, 1×107 inclusion-forming units (IFU) in 0.2 ml of ...sucrose-phosphate glutamate buffer were inoculated intraveneously (iv) via tail veins of mice. Serovar L2 inoculated mice were then treated either with phosphate buffer saline (PBS) or with antibiotics (mg/kg): doxycycline (DOXY), 3.3; ofloxacin (OFLX), 6.6; ampicillin (ABPC), 50 24 hours after inoculation, and were sacrificed by decapitation to monitor the growth of serovar L2 in spleen at intervals on day 1, 2, 3, 4, 5, 7, 11 and 14 (and 20) after inoculation. Ten %(w/v) homogenates of the spleen were made and 0.2 ml of aliquots were inoculated onto Hela 229 cells prepared in 24 well plates for determination of the infective titers (log10 IFU/spleen). In serovar L2 and PBS inoculated mice, the titers peaked 1 to 2 days after inoculation and gradually decreased thereafter. A few or no chlamydial inclusions were demonstrated 14 or 20 days after inoculation. Significant decrease of the titers were observed by injection of the antibiotics. When one DOXY was injected daily, no inclusions were detected after only 2 injections. Eleven injections of 10 mg/kg of OFLX, but not 6.6 mg/kg, were required for eradication of serovar L2. Complete eradication was not observed in ABPC treatment. These results are similar to the results obtained in clinical trials. The enhanced inhibition of growth of serovar L2 in the spleen was observed with an antibiotic treatment in mice which were immunized with the same organism 14 days before use. In conclusion, our present results indicate that mice may serve as a useful animal model for primary evaluation of an in vivo activity of antichlamydial agents.
In the winter months of the year 1977, 64 dams out of 170 ewes pregnant for the first time miscarried on one farm in the locality G., Roznava district. Antibodies were revealed in 97% dams after the ...examination of the blood of 170 ewes from the abortion-affected flock; ornithosis antigen was employed for the examination in the complement-fixing reaction. In the cytoplasm of placentary cells of two miscarrying ewes chlamydiae were proved microscopically. The chlamydiae-strains designated LH-5109 and PK-5082 were isolated by inoculating placentary suspensions to the yolk sacs of chicken embryos. Both strains correspond to all the criteria necessitating the identification of chlamydiae (Storz, 1971). As miscarrying ewes in the course of abortions eliminate, with abortions and amniotic fluids, great amounts of chlamydiae to their environment, they represent a powerful source of infection to healthy animals housed on the same premises and to tending staff. Chlamydiae-antibodies were proved, by the complement-fixing reaction, in the blood of seven attendants out of all the eleven-member tending staff.
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