Metronidazole resistance of Trichomonas vaginalis as a cause of treatment failure in trichomoniasis--A case report.

Six isolates of a strain (MRP-MT) of Trichomonas vaginalis obtained from a woman before and after unsuccessful treatment with metronidazole had an appreciably lower susceptibility to metronidazole both in vitro in the aerobic tube assay and in vivo in the mouse assay than did control strains from patients cured with standard doses of the drug. Our results support recent evidence that metronidazole-resistant strains of T vaginalis do cause treatment failure. Resistance of these strains could be detected in vitro under only aerobic but not anaerobic conditions. The prevalence of metronidazole-resistant strains of T vaginalis should be kept under surveillance in order to estimate their clinical importance. The patient harbouring the resistant strain MRP-MT was finally cured with increased doses of ornidazole.     

Urine culture for the detection of Trichomonas vaginalis in men.

Urine samples were collected from 248 men, 21 of whom were known contacts of women infected with Trichomonas vaginalis. This organism was cultured from only three of the 21 specimens from patients in the contact group. The cultural technique was shown to be capable of reliably detecting small numbers of organisms under practical conditions; it appears, therefore, that most male contacts shed relatively few trichomonads and that the infective dose for women must be correspondingly small.     

巢式聚合酶链反应检测男性尿道炎患者尿液中阴道毛滴虫

目的 建立两种巢式聚合酶链反应（PCR）方法检测男性尿道炎患者尿液中阴道毛滴虫感染状况,评价两种巢式PCR在临床诊断中的应用价值。 方法 2011年4月至2013年12月来我院性病门诊就诊的1 088例男性尿道炎患者为研究对象,收集尿道拭子标本做分泌物涂片镜检、阴道毛滴虫湿片检测以及淋球菌培养,同时收集尿液标本提取DNA,针对阴道毛滴虫重复基因组和β微管蛋白基因,采用两种巢式PCR法检测尿液中阴道毛滴虫。 结果 湿片法检测阴道毛滴虫的阳性率为0,而两种巢式PCR法均检测出29例阳性标本,阳性率为2.67%,且两种巢式PCR法检测出的阳性标本一致。 结论 与湿片法相比,巢式PCR法检测男性尿液标本阴道毛滴虫具有较高的灵敏度和特异性。     

Metronidazole-resistant Trichomonas vaginalis.

A 36-year-old woman with symptomatic metronidazole-resistant trichomonal vaginitis for 10 years had a total of 22 courses of treatment with either metronidazole or tinidazole according to different schedules. The minimum trichomonicidal concentration of metronidazole for the strain of Trichomonas vaginalis isolated from the patient was 160 microgram/ml compared with 1.25-10 microgram/ml for other freshly isolated strains. The former strain also showed a definitely decreased sensitivity to ornidazole and tinidazole (80 microgram/ml). The mechanisms behind the appearance of resistance in this clinical isolate are at present unknown and require further study from the theoretical as well as the therapeutic viewpoint.     

Metronidazole-resistant Trichomonas vaginalis.

A 36-year-old woman with symptomatic metronidazole-resistant trichomonal vaginitis for 10 years had a total of 22 courses of treatment with either metronidazole or tinidazole according to different schedules. The minimum trichomonicidal concentration of metronidazole for the strain of Trichomonas vaginalis isolated from the patient was 160 microgram/ml compared with 1.25-10 microgram/ml for other freshly isolated strains. The former strain also showed a definitely decreased sensitivity to ornidazole and tinidazole (80 microgram/ml). The mechanisms behind the appearance of resistance in this clinical isolate are at present unknown and require further study from the theoretical as well as the therapeutic viewpoint.     

Contraceptive devices as a cause of urethritis

A group of 61 sexual partners were analyzed, including men reporting cases of urethritis and their partners using IUDs. Treatment with antibiotics recommended for NGU was most effective (17 or 21 cases) in those couples infected with chlamydia (group 1), less in couples without chlamydia infections (8 or 16), but maintaining sporadic sexual contacts with other partners (group 2), and was frequently ineffective (10 of 14) in couples without chlamydia infection and without a history of incidental sexual contacts with other partners (group 3). In cases of failure of antibiotic treatment, the symptoms and signs of urethritis regressed in males and inflammatory changes in vaginal discharge disappeared in their partners after IUD removal. In group 3, 10 of 24 couples were not given any antibiotics and IUD removal was the only treatment. (author's modified)     

Abnormal forms of Trichomonas vaginalis.

Abnormal forms of Trichomonas vaginalis have been demonstrated by both conventional and scanning electron microscopy after inoculation of media with clinical material from cases of trichomonal vaginitis. Twenty-six cases of vaginitis have been studied; 10 of them showed the abnormal forms of trichomonads after growth in a modification of the medium described by Bushby and Copp (1955), while 16 showed only normal forms.     

Abnormal forms of Trichomonas vaginalis.

Abnormal forms of Trichomonas vaginalis have been demonstrated by both conventional and scanning electron microscopy after inoculation of media with clinical material from cases of trichomonal vaginitis. Twenty-six cases of vaginitis have been studied; 10 of them showed the abnormal forms of trichomonads after growth in a modification of the medium described by Bushby and Copp (1955), while 16 showed only normal forms.     

Isoenzyme characterisation of Trichomonas vaginalis.

Clones of 32 strains of Trichomonas vaginalis isolated from patients attending a venereal diseases clinic were compared among themselves and with authentic Pentatrichomonas hominis on the basis of their isoenzyme patterns for eight enzymes by thin-layer starch-gel electrophoresis. The enzymes examined were: glucose phosphate isomerase (GPI); phosphoglucomutase (PGM); malic enzyme (NADP+) (ME); hexokinase (HK); malate dehydrogenase (NAD+) (MDH); glucose-6-phosphate dehydrogenase (G6PD); aldolase (ALD); and lactate dehydrogenase (LDH). From the isoenzyme patterns of four enzymes (LDH, MDH, HK, and GPI) the strains of T vaginalis could be divided clearly into five groups. PGM showed differences in only one strain, while two other enzyme patterns (ME and ALD) were the same for all the strains of T vaginalis tested. All isolates were clearly distinguishable from P hominis. Although G6PD patterns were not sharp some differences were evident among T vaginalis strains.     

Contact-independent cytotoxicity of Trichomonas vaginalis.

OBJECTIVE--To test the dependency of haemolytic and cytocidal manifestations of pathogenicity of Trichomonas vaginalis on direct contact between the target cells and the organism. TEST ORGANISM--T vaginalis strain Baltimore 42. DESIGN--Haemolysis in the presence of live T vaginalis and of its filter-sterilised metabolic products was compared. The dependence of haemolytic and cytocidal effects on retention of low pH of metabolic products of the organism was demonstrated by parallel titrations of sterile filtrates in normal saline and in phosphate buffered saline (PBS) pH 7.0. RESULTS--Near complete lysis was obtained when erythrocytes mixed with T vaginalis were incubated for 1 h at 37 degrees C in saline containing 1% glucose. The same degree of haemolysis was present in filter-sterilised glucose-saline in which the organism was incubated (1 h/37 degrees C) before erythrocytes were added and incubated under the same conditions as in the mixture with the organism. The degree of haemolysis in filtrates was dependent on retention of low pH (below 5.0) of the suspending fluid in which the organism alone was incubated. Dilution of filtrates in PBS, as opposed to normal saline, abolished or diminished the haemolytic effect. Presence of glucose (energy source) in the saline during incubation of the organism had a pronounced enhancing effect. The production of haemolytic metabolites was temperature dependent, whereas the haemolytic process per se was not. The effect was not an exclusive property of T vaginalis since it was also demonstrated with other trichomonads. The same filtrates applied to tissue culture exerted cytocidal effect strikingly similar to that observed in the haemolysis experiments. CONCLUSION--Neither haemolytic nor cytocidal effect of T vaginalis was contact-dependent.     

Metronidazole and tinidazole in a single large dose for treating urogenital infections with Trichomonas vaginalis in men.

Seventy-three men with urogenital trichomonal infection were treated with a single daily dose of 1 g tinidazole or 1.5 g metronidazole. Both treatments gave satisfactory results. Wives who were also infected with Trichomonas vaginalis, were less likely to have a recurrence of the infection after their husbands had been given either drug.