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PubMed2003

Drug resistance in the sexually transmitted protozoan Trichomonas vaginalis.

Trichomoniasis is the most common, sexually transmitted infection. It is caused by the flagellated protozoan parasite Trichomonas vaginalis. Symptoms include vaginitis and infections have been associated with preterm delivery, low birth weight and increased infant mortality, as well as predisposing to HIV/AIDS and cervical cancer. Trichomoniasis has the highest prevalence and incidence of any sexually transmitted infection. The 5-nitroimidazole drugs, of which metronidazole is the most prescribed, are the only approved, effective drugs to treat trichomoniasis. Resistance against metronidazole is frequently reported and cross-resistance among the family of 5-nitroimidazole drugs is common, leaving no alternative for treatment, with some cases remaining unresolved. The mechanism of metronidazole resistance in T. vaginalis from treatment failures is not well understood, unlike resistance which is developed in the laboratory under increasing metronidazole pressure. In the latter situation, hydrogenosomal function which is involved in activation of the prodrug, metronidazole, is down-regulated. Reversion to sensitivity is incomplete after removal of drug pressure in the highly resistant parasites while clinically resistant strains, so far analysed, maintain their resistance levels in the absence of drug pressure. Although anaerobic resistance has been regarded as a laboratory induced phenomenon, it clearly has been demonstrated in clinical isolates. Pursuit of both approaches will allow dissection of the underlying mechanisms. Many alternative drugs and treatments have been tested in vivo in cases of refractory trichomoniasis, as well as in vitro with some successes including the broad spectrum anti-parasitic drug nitazoxanide. Drug resistance incidence in T. vaginalis appears to be on the increase and improved surveillance of treatment failures is urged.

Animals↗
PubMed2003

Urinary tract infection with Trichomonas vaginalis in a premature newborn infant and the development of chronic lung disease.

We report a case of a low-birth-weight infant with an infection of the urinary tract with Trichomonas vaginalis, who later developed cystic chronic lung disease suggestive of Wilson-Mikity syndrome. Although she had mild respiratory distress syndrome at birth, the extent of the chronic lung disease was out of proportion to the initial illness. We speculate that maternal infection with this organism may have resulted in an inflammatory response that led to its development.

Adult↗
PubMed1993

Trichomonas vaginalis: characterization of ornithine decarboxylase.

Ornithine decarboxylase (ODC), the lead enzyme in polyamine biosynthesis, was partially purified from Trichomonas vaginalis and its kinetic properties were studied. The enzyme appears to be of special significance in this anaerobic parasite, since the arginine dihydrolase pathway generates ATP as well as putrescine from arginine. ODC from T. vaginalis had a broad substrate specificity, decarboxylating ornithine (100%), lysine (1.0%) and arginine (0.1%). The enzyme had a pH optimum of 6.5, a temperature optimum of 37 degrees C and was pyridoxal 5'-phosphate-dependent. Attempts to separate ornithine- from lysine-decarboxylating activity by thermal-stability and pH-optima curves were not successful. Although Km values for ornithine and lysine were 109 and 91 microM respectively, and the Vmax values for these substrates were 1282 and 13 nmol/min per mg of protein respectively, the most important intracellular substrate is ornithine, since intracellular ornithine levels are 3.5 times those of lysine and extracellular putrescine levels are 7.5 times those of cadaverine. Ornithine was also an effective inhibitor of lysine-decarboxylating activity (Ki 150 microM), whereas lysine was relatively ineffective as inhibitor of ornithine-decarboxylating activity (Ki 14.5 mM). Crude ODC activity was localized (86%) in the 43,000 g supernatant and 3303-fold purification was obtained by (NH4)2SO4 salting and DEAE-Sephacel, agarose-gel and hydroxyapatite chromatography steps. The enzyme bound difluoro[3H]methylornithine ([3H]DFMO) with a ratio of drug bound to activity of 2500 fmol/unit, where 1 unit corresponds to 1 nmol of CO2 released from ornithine/min. The enzyme had a native M(r) of 210000 (gel filtration), with a subunit M(r) of 55,000 (by SDS/PAGE), suggesting that the trichomonad enzyme is a tetramer. From the subunit M(r) and binding ratio of DFMO, there is about 137 ng of ODC per mg of T. vaginalis protein (0.013%). The significant amount of ODC protein present supports the view that putrescine synthesis in T. vaginalis plays an important role in the metabolism of the parasite.

Animals↗
PubMed2000

The interaction of trichomonas vaginalis with epithelial cells, polymorphonuclear leucocytes and erythrocytes on vaginal smears: light microscopic observation.

In this study, vaginal smears taken from 400 patients were examined cytologically using the Papanicolaou technique. Twenty of the 400 patients were detected as harbouring Trichomonas vaginalis. The interactions of T. vaginalis with epithelial cells, polymorphonuclear leucocytes (PMNLs) and erythrocytes were determined at light microscopic level. It was observed that T. vaginalis were juxtaposed to the epithelial cells and changed shape according to the contours of the epithelial cell revealing the cytopathic effect of trichomonads on epithelial cells. Trichomonads attached to PMNLs produced pseudopodia to phagocytose the cells. Occasionally an amoeboid shaped T. vaginalis organism was seen trailed by a row of PMNLs. This light microscopic study supports the production by trichomonads of a chemotactic factor for PMNLs. Phagocytosed erythrocytes were also seen in the cytoplasm of T. vaginalis, suggesting the need for the patient to be tested for anaemia.

Adolescent↗
PubMed1998

Chitinolytic activities in Trichomonas vaginalis.

Chitinolytic activities were identified in the Protozoa Trichomonas vaginalis. Overall chitinase activity assessed using chitine-azure as substrate was 10.93 +/- 1.21 nmoles/min/mg prot. End nonreducing chitobiosidase (exochitinase) and chitotriosidase (endochitinase) activities were shown using p-nitrophenyl-substrates and had specific activities of 4.55 +/- 0.53 and 0.47 +/- 0.06 nmol/min/mg prot, Kmapp. = 1.32 mM and 5 microM and pH optimum = 7.0 and 6.1 respectively. beta-N-acetylhexosaminidase (NAHase) activity was also detected with a specific activity of 5.40 +/- 0.65 nmol/min/mg prot., Kmapp = 0.656 mM and pH optimum at 7.0. No release of these enzymes into the culture medium was found. The possible role of chitinases in T. vaginalis remains to be investigated.

Animals↗
PubMed1998

Trichomonas tenax empyema in an immunocompromised patient with advanced cancer.

A 53-year-old male acromegalic patient with advanced rectal adenocarcinoma developed pleuritis in the course of cobalt irradiation, steroid treatment and chemotherapy. Examination of drained pleural fluid demonstrated numerous motile organisms, which were identified as Trichomonas tenax by Giemsa staining. Peptostreptococcus micros was also detected in the cultures of pleural fluid and blood. Treatment with metronidazole successfully eliminated the protozoa and cured the pyothorax.

Acromegaly↗
PubMed2001

Failure of metronidazole to prevent preterm delivery among pregnant women with asymptomatic Trichomonas vaginalis infection.

BACKGROUND: Infection with Trichomonas vaginalis during pregnancy has been associated with preterm delivery. It is uncertain whether treatment of asymptomatic trichomoniasis in pregnant women reduces the occurrence of preterm delivery. METHODS: We screened pregnant women for trichomoniasis by culture of vaginal secretions. We randomly assigned 617 women with asymptomatic trichomoniasis who were 16 to 23 weeks pregnant to receive two 2-g doses of metronidazole (320 women) or placebo (297 women) 48 hours apart. We treated women again with the same two-dose regimen at 24 to 29 weeks of gestation. The primary outcome was delivery before 37 weeks of gestation. RESULTS: Between randomization and follow-up, trichomoniasis resolved in 249 of 269 women for whom follow-up cultures were available in the metronidazole group (92.6 percent) and 92 of 260 women with follow-up cultures in the placebo group (35.4 percent). Data on the time and characteristics of delivery were available for 315 women in the metronidazole group and 289 women in the placebo group. Delivery occurred before 37 weeks of gestation in 60 women in the metronidazole group (19.0 percent) and 31 women in the placebo group (10.7 percent) (relative risk, 1.8; 95 percent confidence interval, 1.2 to 2.7; P=0.004). The difference was attributable primarily to an increase in preterm delivery resulting from spontaneous preterm labor (10.2 percent vs. 3.5 percent; relative risk, 3.0; 95 percent confidence interval, 1.5 to 5.9). CONCLUSIONS: Treatment of pregnant women with asymptomatic trichomoniasis does not prevent preterm delivery. Routine screening and treatment of asymptomatic pregnant women for this condition cannot be recommended.

Adult↗
PubMed2002

Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth.

OBJECTIVE: The purpose of this study was to determine whether sexual intercourse was associated with the treatment efficacy or the incidence of preterm birth in two large randomized trials in which metronidazole treatment of bacterial vaginosis or Trichomonas vaginalis did not reduce preterm birth. STUDY DESIGN: Secondary analysis of two multicenter, double-blind, placebo-controlled trials in which women with asymptomatic bacterial vaginosis on Gram stain or asymptomatic T vaginalis on culture were randomized at 16 to 23 weeks of gestation to metronidazole or placebo. In both studies, women took 2 g of metronidazole or placebo in the presence of a nurse (first dose) and were given a second dose to take 48 hours later. This regimen was repeated (third and fourth doses) at 24 to 29 weeks. At the time of the third dose, bacterial vaginosis and T vaginalis specimens were collected again. Patients who were randomly selected to receive metronidazole were analyzed for bacterial vaginosis and T vaginalis at 24 to 29 weeks and for preterm birth of <37 weeks of gestation, according to intercourse between first and second doses and between the second and third doses. Continuous variables were compared with the use of the Wilcoxon rank-sum test; categoric variables were compared with the use of the chi(2 ) test, Fisher exact test, or the Mantel-Haenzel test of trend. RESULTS: Sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of bacterial vaginosis (18% vs 24%; relative risk, 0.7; 95% CI, 0.5-1.1; and 23% vs 20%; relative risk, 1.2; 95% CI, 0.9-1.6, respectively) or T vaginalis (4% vs 8%; relative risk, 0.5; 95% CI, 0.1-3.6; and 5% vs 10%; relative risk, 0.5; 95% CI, 0.2-1.1; respectively) at 24 to 29 weeks of gestation compared with no intercourse. In the T vaginalis trial, sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of preterm birth (13% vs 17%; relative risk, 0.8; 95% CI, 0.3-2.1; and 16% vs 17%; relative risk, 1.0; 95% CI, 0.6-1.6; respectively) compared with no intercourse. In the bacterial vaginosis trial, although sexual intercourse between the first and second doses did not influence the incidence of preterm birth (11% vs 12%; relative risk, 0.9; 95 % CI, 0.6-1.5), sexual intercourse between the second and third doses was associated with a reduction in the incidence of preterm birth (10% vs 16%; relative risk, 0.6; 95% CI, 0.4-0.9) compared with no intercourse. CONCLUSION: Sexual intercourse was associated with neither the efficacy of metronidazole treatment of bacterial vaginosis or T vaginalis nor with the incidence of preterm birth. In the bacterial vaginosis study, intercourse between the second and third doses had a negative association with preterm birth.

Black or African American↗
PubMed1988

Antiparasitic activity of nine pyrazole derivatives against Trichomonas vaginalis, Entamoeba invadens and Plasmodium berghei.

Nine nitropyrazole derivatives were prepared and tested against Trichomonas vaginalis in vitro and in vivo, Entamoeba invadens in vitro and Plasmodium berghei in vivo. Three of the compounds, 4-4-nitropyrazole, 1-methyl-4-nitropyrazole and 4,4'-dinitro-1,1'-methylenedipyrazole, have an activity similar to that of metronidazole (used as the reference compound) against T. vaginalis and E. invadens after 48 hours of incubation. All the compounds tested were inactive against P. berghei.

Animals↗
PubMed1997

One-tube, nested-PCR assay for the detection of Trichomonas vaginalis in vaginal discharges.

To shorten the time and improve the accuracy of diagnosis of vaginal trichomoniasis, a novel, one-tube, nested PCR, which targets a family of 650-bp specific DNA repeats from the Trichomonas vaginalis genome, has been developed. Samples were prepared by a rapid boiling method and the PCR products analysed by gel electrophoresis. A 290-bp DNA fragment was observed in all positive cases. No cross-reaction with any other pathogens, including the Pentatrichomonas hominis and Giardia lamblia used as controls, was found. Using the assay, one genome-equivalent of T. vaginalis in 20 microliters vaginal discharge can be detected and diagnosis can be made within 6 h. When 165 clinical specimens were examined by wet amount, culture and the PCR assay, 16 were found positive for T. vaginalis by both culture and PCR, whereas only nine of these 16 cases were found to be positive by examination of wet mounts. No PCR-negative cases were positive by wet mount or culture. This new assay appears to be a simple, rapid, accurate and sensitive method for the diagnosis of vaginal trichomoniasis.

Animals↗
PubMed2005

Trichomonas vaginalis: paradigm of a successful sexually transmitted organism.

Trichomonas vaginalis (TV) is one of the most successful protozoan pathogens and one of the most common sexually transmitted organism in females, yet it is also one of the most poorly investigated. By producing a wide array of glycosidases and cysteine proteinase enzymes, the organism can easily adapt to the environment, harvesting host proteins and DNA for metabolism. With the ability to cause lesions, vaginitis and acute inflammatory disease of the genital mucosa, TV acts as a potential catalyst in the acquisition of secondary infections including human immunodeficiency virus (HIV) and human papillomavirus (HPV), the organism responsible for the pathogenesis of cervical cancer. Treatment of TV infection is relatively easy and could dramatically reduce the transmission of HIV in areas where TV is endemic.

AIDS-Related Opportunistic Infections↗
PubMed2005

Real-time PCR improves detection of Trichomonas vaginalis infection compared with culture using self-collected vaginal swabs.

OBJECTIVE: To compare a real-time polymerase chain reaction (PCR) assay with broth culture for the detection of Trichomonas vaginalis using self-collected vaginal swabs. METHODS: Self-collected vaginal swabs were obtained from adolescent and young adult African-American women participating in HIV-1 prevention programs. T. vaginalis culture was performed using the InPouch TV System. Samples for the real-time PCR assay were collected using the BDProbeTec ET Culturette Direct Dry Swab system and tested in a laboratory-developed assay which targeted a repeated sequence of the genome. Discrepant samples that were culture negative and positive in the real-time PCR assay were tested in a confirmatory PCR which targeted a different region of the T. vaginalis genome, the18S ribosomal DNA gene. RESULTS: Of the 524 specimens tested by both culture and real-time PCR, 36 were culture positive and 54 were positive in the real-time PCR assay; 16 of the 18 discrepant specimens were also positive in the confirmatory PCR assay. Using a modified gold standard of positive by culture or positive in both PCR assays, the sensitivity of the real-time PCR assay was 100% and the specificity was 99.6%, whereas culture had a sensitivity of 69.2% and a specificity of 100%. CONCLUSIONS: The real-time PCR assay was sensitive and specific for the detection of T. vaginalis DNA from self-collected vaginal swab specimens. The ability to use the BDProbeTec dry swab system for the real-time PCR testing allowed for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and T. vaginalis from a single specimen.

Adolescent↗
PubMed2001

Screening for sexually transmitted diseases in human immunodeficiency virus-positive patients in Peru reveals an absence of Chlamydia trachomatis and identifies Trichomonas vaginalis in pharyngeal specimens.

To determine the prevalence of sexually transmitted diseases (STDs), we screened 107 human immunodeficiency virus-positive patients in Peru, where the virus is predominantly sexually transmitted. Patients had multiple risk factors for STDs, and 38% of women and 50% of men had at least 1 STD (gonorrhea, trichomoniasis, herpes simplex, anogenital warts, or syphilis seropositivity). No chlamydial infection was detected, even though infection rates in the general population are 5%-12%. Patients receiving trimethoprim-sulfamethoxazole(TMP-SMZ) for prophylaxis or treatment of respiratory infections were least likely to have cervicitis and/or urethritis (odds ratio, 0.37; 95% confidence interval, 0.15-0.89). Although not optimal treatment, administration of TMP-SMZ is effective against chlamydial infection. We speculate that the use of concomitant medications, such as TMP-SMZ, may be inadvertently preventing chlamydial infection in this population. Another finding was the presence of Trichomonas vaginalis in pharyngeal specimens of 3 men with histories of orogenital activity. This has not been previously reported and requires further study.

Adolescent↗
PubMed2002

Trichomonas vaginalis is associated with pelvic inflammatory disease in women infected with human immunodeficiency virus.

We assessed the association between the causative agents of vaginal discharge and pelvic inflammatory disease (PID) among women attending a rural sexually transmitted disease clinic in South Africa; the role played by coinfection with human immunodeficiency virus type 1 (HIV-1) was studied. Vaginal and cervical specimens were obtained to detect Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and bacterial vaginosis. HIV-1 infection was established by use of serum antibody tests. A total of 696 women with vaginal discharge were recruited, 119 of whom had clinical PID. Patients with trichomoniasis had a significantly higher risk of PID than did women without trichomoniasis (P=.03). PID was not associated with any of the other pathogens. When the patients were stratified according to HIV-1 status, the risk of PID in HIV-1-infected patients with T. vaginalis increased significantly (P=.002); no association was found in patients without HIV-1. T. vaginalis infection of the lower genital tract is associated with a clinical diagnosis of PID in HIV-1-infected women.

AIDS-Related Opportunistic Infections↗
PubMed2002

Double-stranded RNA viral infection of Trichomonas vaginalis infecting patients attending a sexually transmitted diseases clinic.

Trichomonas vaginalis (TV) can be infected with double-stranded RNA (dsRNA) viruses that may have important implications for trichomonal virulence and disease pathogenesis. A cross-sectional study was conducted in a sexually transmitted diseases clinic to determine the prevalence and clinical significance of dsRNA viral infection of TV infecting men and women. Overall, dsRNA virus was present in 21 (75%) of 28 TV isolates (95% confidence interval [CI], 55%-89%). dsRNA viral infection of TV was not associated with the presence of discharge, dysuria, genital pruritus, or genital irritation or odor. However, patients with virus-positive isolates were significantly older than patients with virus-negative isolates (median age, 38 vs. 23 years; P=.003), and virus-positive isolates were more prevalent among women (19 [86%] of 22 isolates; 95% CI, 65%-97%) than among men (2 [33%] of 6 isolates; P=.02). The age and sex specificity of virus-positive isolates may aid in understanding the differences in chronicity and clinical presentation of TV in men and women.

Adult↗
PubMed2002

Trichomonas vaginalis polymerase chain reaction compared with standard diagnostic and therapeutic protocols for detection and treatment of vaginal trichomoniasis.

Wet preparation has limited sensitivity for diagnosis of Trichomonas vaginalis (TV) infection. An observational study of 337 women was conducted to evaluate a new polymerase chain reaction (PCR) test for TV. The sensitivities of wet preparation and TV culture were 52% (95% confidence interval [CI], 41-62) and 78% (95% CI, 69-86), respectively. TV PCR had a sensitivity of 84% (95% CI, 75-90) and a specificity of 94% (95% CI, 90-97). Metronidazole was provided to 67 (69%) of 97 women with TV because of TV on wet preparation, exposure to TV, or a diagnosis of bacterial vaginosis or pelvic inflammatory disease; however, if TV PCR had been used for diagnosis, 81 (84%) of 97 women with TV would have been treated (P=.02). TV is significantly undertreated using standard algorithms for metronidazole therapy. Given the association of trichomoniasis with perinatal morbidity and HIV transmission, women in high-risk groups may benefit from TV PCR.

Adolescent↗
PubMed2004

The use of specimens from various genitourinary sites in men, to detect Trichomonas vaginalis infection.

Variations in estimates of prevalence of trichomoniasis in men may reflect true differences in the burden of disease but are also affected by the performance of diagnostic methods and the type of specimen tested. In this study, men were evaluated at baseline and at follow-up, to evaluate syndromic management of urethritis and the effects of human immunodeficiency virus and trichomoniasis, in Lilongwe, Malawi. First-void urine specimens and urethral swabs were obtained at enrollment, for Trichomonas vaginalis culture; semen specimens were also obtained at follow-up. The sensitivities of testing methods using urine specimens and urethral swabs were equal; 67% of cases were identified by use of either specimen, and, in 47% of cases, both specimens tested positive. When semen specimens were included, all 3 specimens tested positive in only 19% of cases. Semen was the most sensitive single specimen, and, in 25.6% of cases, only semen specimens tested positive. Thus, prevalence of T. vaginalis infection in men is underestimated if only 1 specimen is tested.

Adolescent↗