Searching For A New Method Of Detecting Chlamydia Trachomatis And Antibiotic Susceptibility Testing In Vitro With UF-100 Flowcytometer

Chlamydia trachomatis is an important intracellular pathogen causing various urogenital infections and is one of the most common sexual transmitted pathogens in some countries. Chlamydia trachomatis can cause urethritis, cervicitis, conjunctivitis, pelviperitonitis, lymphogranuloma venereum, which sometimes accompanied with dysgenesis, agenesis and atopic pregnancy. The clinical detection method of chlamydia trachomatis involves cell culture, immunofluorescence and molecular biochemistry. Tetracyclines have been used frequently, ofloxacin , azithromycin have always been the alternative drugs.The recurrent infection of chlamydia trachomatis is common in clinic and the test results persist positive. The detection method of chlamydia trachomatis and antichlamydial activity of antibiotics in vitro is valuable in clinic, which is rapid, simple, objective and accurate.We used UF-100 flow cytometer to detect chlamydia trachomatis andantichlamydial activity of antibiotics in vitro, in order to develop an objective, practical and accurate method to support the clinical therapy. The UF-100 is a second-generation automated analyzer that performs and analysis of the formed elements in urine by using flow cytometry. The stained formed elements is transferred to the reaction unit, then is irradiated by an argon laser beam. The fluorescence, the pulse intensity and the pulse width of the forward-scattered light are measured. Through multi-parameter analysis, the results is displayed by / μ L, /HPF and /LPF, which is accurate and objective.127 clinical strains were isolated from patients with standard method.(1) Detection of chlamydia trachomatis: 14 chlamydia trachomatis positive strains were tested by UF-100. the chlamydia trachomatis count(>1000/mL) was determined by the bacteria count in the sample. (2) Detection of antichlamydial activity of antibiotics in vitro: 12 positive strains were tested by UF-100.We selected doxycycline, ofloxacin, minocycline, azithromycin and diluted 4 degrees of concentration respectively. 1C (inhibitory concentration) 50 was tested by UF-100 to evaluate the antichlamydial activity of the drugs in vitro. Minocycline (IC50 value is 0.03mg/L) has the highest antichlamydial activity, next doxycycline (IC50 value is 0.043mg/L) , then azithromycin (IC50 value is 0.22mg/L) , and ofloxacin (IC50 value is 0.27mg/L) is the lowest.We used UF-100 flow cytometer to detect chlamydia trachomatis and antichlamydial activity of antibiotics by analyzing the bacteria count and IC50 of the sample. The results accord with that of the immunofluorescent method. This method is rapid, objective, accurate, multi-parameter, reproducible, and is less subjective than immunofluorescent method. If s valuable in study and recommendable in clinic.