Study Of The Correlation Between Gardnerella Vaginalis And Bacterial Vaginosis

Background & objectivesGardnerella vaginalis(GV) is a kind of gram-negative or gram-variable pleomorphic small short rod. It was found at first by Gardner and Dukes in a female genital tract with gray and odorant discharge in 1955,and got its name in 1980. Recent studies have demonstrated that GV dominates among the Bacterial vaginosis(BV) microorganisms. Besides BV,infection of GV may result in many diseases and complications. In addition , dual or multiple infection of GV with chlamydia tramatis and ureaplasma urealyticum is very common. It could also stimulate the expression of HIV in lymphocyte and mononuclear-phagcytic system dramatically,which has a correlation with the spreading of HIV.GV could be transmitted by sexual contact .Because of its atypical clinical syndromes, GV endangers the women's health and has a significant influence on the public health .So it's very necessary to study GV further.Our research is to investigate the method of GV's isolation, cultivation,antibiotic sensitivity and also its correlation with BV, offering useful clues for clinical diagnosis and treatment. Methods(1) Isolation and cultivation of GV : inoculate the specimen on BBC plate ,then put it in the circumstance with a humidified atmosphere with 5% CO₂ at 37℃ .Select the colonies which are harvested after a 48-h incubation and then conduct a series of biochemical tests such as gram stain ,oxidase and catalase tests,starch fementation,hippurate hydrolysis etc.(2)Antibiotic sensitivity : K-B paper method was used in this part.The drugs include tetracycline ,ciprofloxacin,clindamycin, penicillin G and metronazole .(3) correlation between GV and BV: BV was diagnosed by the Amsel's criteria (the cluecell was examined by the method ofacridine orange , gram stain and salt solution).Analyze the relationship between GV and BV,and also the feasibility of detecting the cluecell with acridine orange staining. Results(1) Isolation and cultivation of GV : The P -hemolytic transparent colonies were harvested on BBC plate after a 48-h incubation at 37°C in a humidified atmosphere with 5% CO2 .It's a kind of Gram-negative and variable plemorphic small rod, and was able to ferment starch, hydrolyse hippurate ,while the other tests were negative. 66 clinical GV strains were identified from 285 clinical specimens.(2)Antibiotic sensitivity: their senstivity to tetracycline , ciprofloxacin, clindamycin was 81.81%, 74.24% and 86.36% respectively.Drug resistance rate to penicillin G and metronazole wasl6.67% and 42.42% respectively.(3) Correlation between GV and BV: 58 women including 48 who visited STI clinic were diagnosed as BV. The ratio was 20.35%. The rate of GV infection among women with BV was 53.45%, much higher than that of normal group.(4) Feasibility of detecting cluecell with acridine orange staining: this method has almost the same coincidence as gram stain (Kappa=0.6944) . Conclusions(1) GV could be cultivated on the culture with rabbit blood (2) GV was sensitive to tetracycline , ciprofloxacin,clindamycin.The results were in coincidence with domestic reports. Some GV strains have shown resistance to metrodazole and penicillin G (3) the results also suggested that the ratio of BV in sexually transmitted infections( STI) patients was much higher than that of healthy women. In addition , the women who visited STI clinic were likely to have other STIs . The detection rate of GV in BV team was higher than that of non-BV team .(4) Acridine orange staining method was equal to gram stain method in cluecell detection.