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Background: Trichomonas gallinae is a protozoan parasite responsible for canker in pigeons, a debilitating disease that causes significant economic losses. While metronidazole (MTZ) remains the primary treatment, the emergence of resistance is a growing concern. This study investigated the efficacy of eugenol and its nanoemulsion formulation against T. gallinae in both in vitro and in vivo settings., Aim: To evaluate the anti-trichomonal activity of eugenol, eugenol nanoemulsion, and MTZ against T. gallinae using in vitro and in vivo models., Methods: In vitro , T. gallinae trophozoites were exposed to varying concentrations of eugenol and eugenol nanoemulsion (0.625-10 μg/ml), as well as MTZ (25 μg/ml). Cytotoxicity was assessed using Vero cells. In vivo , 120 pigeons were experimentally infected and treated with either eugenol (10 mg/kg), eugenol nanoemulsion (10 mg/kg), MTZ (25 mg/kg), or left untreated. Treatments were administered daily for 5 days., Results: In vitro , both eugenol and its nanoemulsion at 10 μg/ml achieved 100% lethality of T. gallinae after 48 hours, while MTZ reached the same effect within 24 hours. In vivo , MTZ and eugenol (at 25 mg/kg and 10 mg/kg, respectively) resulted in 100% recovery of infected pigeons 5 days post-treatment. Notably, eugenol nanoemulsion (10 mg/kg) achieved 100% recovery within just 4 days post-treatment., Conclusion: This study highlights the potential of eugenol and its nanoemulsion as alternative treatments for T. gallinae infections in pigeons. The eugenol nanoemulsion, in particular, demonstrated promising results with faster recovery rates compared to both MTZ and eugenol, suggesting it may be especially effective against MTZ-resistant strains. Further research is warranted to explore the efficacy and safety of these agents for treating T. gallinae infections in pigeons., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Trichomonas tenax is an oral protozoan with an estimated global pooled prevalence of 17% in the human population.1 Observational studies have demonstrated a significant statistical correlation between oral colonization by T. tenax and the progression of periodontal disease.2 Proposed pathogenic mechanisms for this protozoan include the production of tissue-damaging enzymes, induction of apoptosis in human cells, and dysbiosis of the oral microbiome.3 In patients for whom metronidazole (MTZ) is contraindicated, phytochemicals may offer a viable alternative for controlling T. tenax. Various plant extracts have shown promising in vitro activity against other trichomonads, such as T. vaginalis and Tritrichomonas foetus, as reviewed by Friedman et al.4.

Background: We previously reported that the tomato glycoalkaloid tomatine inhibited the growth of Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus-like strain C1 that cause disease in humans and farm and domesticated animals. The increasing prevalence of antibiotic resistance requires development of new tools to enhance or replace medicinal antibiotics., Methods: Wild tomato plants were harvested and divided into leaves, stems, and fruit of different colors: green, yellow, and red. Samples were freeze dried and ground with a handheld mill. The resulting powders were evaluated for their potential anti-microbial effects on protozoan parasites, bacteria, and fungi. A concentration of 0.02% (w/v) was used for the inhibition of protozoan parasites. A high concentration of 10% (w/v) solution was tested for bacteria and fungi as an initial screen to evaluate potential anti-microbial activity and results using this high concentration limits its clinical relevance., Results: Natural powders derived from various parts of tomato plants were all effective in inhibiting the growth of the three trichomonads to varying degrees. Test samples from leaves, stems, and immature 'green' tomato peels and fruit, all containing tomatine, were more effective as an inhibitor of the D1 strain than those prepared from yellow and red tomato peels which lack tomatine. Chlorogenic acid and quercetin glycosides were present in all parts of the plant and fruit, while caffeic acid was only found in the fruit peels. Any correlation between plant components and inhibition of the G3 and C1 strains was not apparent, although all the powders were variably effective. Tomato leaf was the most effective powder in all strains, and was also the highest in tomatine. S. enterica showed a minor susceptibility while B. cereus and C. albicans fungi both showed a significant growth inhibition with some of the test powders. The powders inhibited growth of the pathogens without affecting beneficial lactobacilli found in the normal flora of the vagina., Conclusions: The results suggest that powders prepared from tomato leaves, stems, and green tomato peels and to a lesser extent from peels from yellow and red tomatoes offer potential multiple health benefits against infections caused by pathogenic protozoa, bacteria, and fungi, without affecting beneficial lactobacilli that also reside in the normal flora of the vagina., (© 2021. The Author(s).)

Clinical resistance to drugs and diminution in their side effects have become great issues for pharmacologists. In veterinary medicine, parasites like Trichomonas gallinae are of veterinary, hygienic and economic importance and can be treated by metronidazole. Unfortunately, scientific evidence has been reported about its resistance and serious side effects in trichomoniasis. In this research, it was attempted to introduce a new procedure to lower side effects of the drug molecules and also, enhance the treatment of disease. Whisker-formed SBA-15 nanoparticles were utilized for the first time in this issue. They had mesoporous structures which metronidazole molecules could be trapped in them. Additionally, these crystalline nanowhiskers were modified with tannic acid to make the release process better. The branches of tannic acid covered the opening of pores in crystalline SBA-15 nanowhiskers and restricted the drug from fast release. It caused a controlled metronidazole release in the smart drug delivery. These nanocarriers were completely tested by several experiments. Whisker-like SBA-15 nanocrystals had a mesopore volume of 0.5931 cm 3 /g, pore diameter of 6.06 nm and surface area of 491.38 m 2 /g. Based on TGA analysis, 10% of tannic acid was coated on the crystalline nanowhiskers during the modification. The metronidazole content and entrapment efficiency of final nanocarriers was 28.56% and 71.40%, respectively. The decomposition of tannic acid in lower pHs made whisker-like SBA-15@tannic acid nanocrystals be pH-responsive which can be used for other applications in the pharmacology. In-vitro study revealed that the minimal lethal concentration of nanocarriers was 0.5 mg/mL for 180 min., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Protozoa, such as Trichomonas tenax, Entamoeba gingivalis and Leishmania braziliensis, may be present in the mouth but their role in the pathophysiology of oral diseases is not clear yet. The use of various types of mouthrinses plays an important role in maintaining proper oral hygiene and in removing some of the microbial components from the oral cavity. The purpose of this study was to investigate the effects of selected mouthrinses on the reference strains of Trichomonas tenax and Entamoeba gingivalis which can be a part of the oral cavity microbiota. Two standard strains Trichomonas tenax (ATCC 30207) and Entamoeba gingivalis (ATCC 30927) were used and metronidazole as a drug used in the treatment of infections caused by protozoa as well as fourteen agents used as mouthwashes were tested, with two pure compounds acting as mouthrinse ingredients, i.e. 20% benzocaine and 0.2% chlorhexidine, as well as 12 commercially-available formulas: Azulan, Colgate Plax Complete Care Sensitive, Corsodyl 0.2%, Curasept ADS 205, Dentosept, Dentosept A, Eludril Classic, Listerine Total Care, Octenidol, Oral-B Pro-Expert Clinic Line, Sylveco and Tinctura salviae. The protozoonicidal activity of the preparations was evaluated on the basis of the ratio of dead to living ratios after incubation in an incubator (37°C) for 1, 10 and 30 min. Protozoa were counted in the Bürker chamber in each case up to 100 cells in an optical microscope (over 400×). The criterion for the death of protozoa was the lack of movement and changes in the shape and characteristics of cell disintegration. The curves of activity were obtained after experiments conducted for 5–7 different solutions of each preparation. On the basis of the curves, the solution killing 50% of the population (CL50) was calculated. All mouthrinses tested in this work in their undiluted form acted lethally on both protozoa. Benzocaine, used as a local anesthetic, has etiotropic properties which can be useful for supporting antiprotozoal treatment. Chlorhexidine confirmed its high efficiency in the eradication of potentially pathogenic protozoa. The use of mouthrinses is an important complement for other procedures intended to maintain correct oral hygiene.

Potato peel, a waste product of the potato processing industry, is high in bioactive compounds. We investigated the in vitro antitrichomonad activity of potato peel powders prepared from commercial Russet, red, purple, and fingerling varieties as well as several known potato components, alkaloids and phenolic compounds, against three pathogenic strains of trichomonads. Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes the human disease trichomoniasis. Two distinct strains of the related Tritrichomonas fetus infect cattle and cats. The glycoalkaloids α-chaconine and α-solanine were highly active against all parasite lines, while their common aglycone solanidine was only mildly inhibitory. α-Solanine was several times more active than α-chaconine. The phenolic compounds caffeic and chlorogenic acids and quercetin were mildly active against the parasites. Most of the potato peel samples were at least somewhat active against all three trichomonad species, but their activities were wide-ranging and did not correspond to their glycoalkaloid and phenolic content determined by HPLC. The two Russet samples were the most active against all three parasites. The purple potato peel sample was highly active against bovine and mostly inactive against feline trichomonads. None of the test substances were inhibitory toward several normal microflora species, suggesting the potential use of the peels for targeted therapeutic treatments against trichomonads.

One of the most poorly studied areas of protozoology is metabolic processes of parasitic protozoa. Study of the biochemistry of parasites required for the development of effective chemotherapy of protozoal diseases. Some amitochondrial parasites of humans, such as Giardia intestinalis, Entamoeba histolytica, Trichomonas sp., living in an environment with low oxygen content, have specialized cellular organelles-hydrogenosomes (like mitochondria provide cells with simple energy). The study of the functioning of these organelles allows us to consider them as targets for the development of аntiprotozoal drugs. The target for chemotherapy in the treatment of trypanosomiasis can be processes related to the characteristics of the glycolytic pathway or a decrease in the level of energy substrate, such as glucose. This leads to a rapid decrease in ATP levels in the cell of the parasite, an overall loss of mobility and disappearance of trypanosomes from the bloodstream of the infected host. Also, glucose transporters located in the membrane of the parasite can be targets for drugs.

Trichomonas vaginalis is a major non-viral sexually-transmitted infection resulted into serious obstetrical and gynecological troubles. The increasing resistance to nitroimidazole therapy and recurrence makes it crucial to develop new drugs against trichomoniasis. Over the past few years, a large number of research articles highlighting the synthetic and natural product research to combat Trichomonas vaginalis have been published. Electronic databases were searched to collect all data from the year 2006 through June 2017 for anti-Trichomonas activity potential of synthetic and natural products. This review article put together the synthetic and natural product research to find out an effective metronidazole alternative to cure trichomoniasis., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Sexually transmitted diseases like trichomoniasis along with opportunistic fungal infections like candidiasis are major global health burden in female reproductive health. In this context a novel non-nitroimidazole class of substituted carbamothioic amine-1-carbothioic thioanhydride series was designed, synthesized, evaluated for trichomonacidal and fungicidal activities, and was found to be more active than the standard drug Metronidazole (MTZ). Compounds were trichomonicidal in the MIC ranges of 4.77-294.1 μM and 32.46-735.20 μM against MTZ-susceptible and -resistant strains, respectively. Further, compounds inhibited the growth of at least two out of ten fungal strains tested at MIC of 7.50-240.38 μM. The most active compound (20) of this series was 3.8 and 9.5 fold more active than the MTZ against the two Trichomonas strains tested. Compound 20 also significantly inhibited the sulfhydryl groups present over Trichomonas vaginalis and was found to be more active than the MTZ in vivo. Further, a docking analysis carried out with cysteine proteases supported their thiol inhibiting ability and preliminary pharmacokinetic study has shown good distribution and systemic clearance., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

1. This study was designed to evaluate the antitrichomonal effects of P. harmala alkaloid extract against T. gallinae, both in vitro and in vivo, as well as comparing it to that of metronidazole, conventional antitrichomonal medication and harmine and harmaline, the two alkaloids present in P. harmala. 2. T. gallinae were collected by the wet mount method from infected free-living pigeons. The in vitro assay was performed using multi-well plates containing test compounds in final concentrations of 5, 10, 15, 20, 30, 50 or 100 μg/ml. The in vivo assay was done on 60 experimentally infected pigeons dosed with metronidazole at 50 mg/kg body weight (BW) or alkaloids at 25 mg/kg BW. 3. The 24 h minimum inhibitory concentration (MIC) of alkaloid extract was 15 µg/ml while that of metronidazole was 50 µg/ml. Harmine and harmaline revealed 24 h MIC of 30 and 100 µg/ml, respectively. Treatment of infected pigeons with alkaloids led to a full recovery after 3 d but with metronidazole total eradication of trophozoites was not achieved. 4. In conclusion, data of the present study suggested P. harmala is a potent natural anti-trichomonal agent, effective against T. gallinae.

Ornidazole of the 5-nitroimidazole drug family is used to treat protozoan and anaerobic bacterial infections via a mechanism that involves preactivation by reduction of the nitro group, and production of toxic derivatives and radicals. Metronidazole, another drug family member, has been suggested to affect photosynthesis by draining electrons from the electron carrier ferredoxin, thus inhibiting NADP + reduction and stimulating radical and peroxide production. Here we show, however, that ornidazole inhibits photosynthesis via a different mechanism. While having a minute effect on the photosynthetic electron transport and oxygen photoreduction, ornidazole hinders the activity of two Calvin cycle enzymes, triose-phosphate isomerase (TPI) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Modeling of ornidazole's interaction with ferredoxin of the protozoan Trichomonas suggests efficient electron tunneling from the iron-sulfur cluster to the nitro group of the drug. A similar docking site of ornidazole at the plant-type ferredoxin does not exist, and the best simulated alternative does not support such efficient tunneling. Notably, TPI was inhibited by ornidazole in the dark or when electron transport was blocked by dichloromethyl diphenylurea, indicating that this inhibition was unrelated to the electron transport machinery. Although TPI and GAPDH isoenzymes are involved in glycolysis and gluconeogenesis, ornidazole's effect on respiration of photoautotrophs is moderate, thus raising its value as an efficient inhibitor of photosynthesis. The scarcity of Calvin cycle inhibitors capable of penetrating cell membranes emphasizes on the value of ornidazole for studying the regulation of this cycle., (© 2016 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.)

Two series of new 5-nitroindazole derivatives, 1-substituted 2-benzylindazolin-3-ones (6-29, series A) and 3-alkoxy-2-benzyl-2H-indazoles (30-37, series B), containing differently functionalized chains at position 1 and 3, respectively, have been synthesized starting from 2-benzyl-5-nitroindazolin-3-one 5, and evaluated against the protozoan parasites Trypanosoma cruzi and Trichomonas vaginalis, etiological agents of Chagas disease and trichomonosis, respectively. Many indazolinones of series A were efficient against different morphological forms of T. cruzi CL Brener strain (compounds 6, 7, 9, 10 and 19-21: IC50 = 1.58-4.19 μM for epimastigotes; compounds 6, 19-21 and 24: IC50 = 0.22-0.54 μM for amastigotes) being as potent as the reference drug benznidazole. SAR analysis suggests that electron-donating groups at position 1 of indazolinone ring are associated with an improved antichagasic activity. Moreover, compounds of series A displayed low unspecific toxicities against an in vitro model of mammalian cells (fibroblasts), which were reflected in high values of the selectivity indexes (SI). Compound 20 was also very efficient against amastigotes from Tulahuen and Y strains of T. cruzi (IC50 = 0.81 and 0.60 μM, respectively), showing low toxicity towards cardiac cells (LC50 > 100 μM). In what concerns compounds of series B, some of them displayed moderate activity against trophozoites of a metronidazole-sensitive isolate of T. vaginalis (35 and 36: IC50 = 9.82 and 7.25 μM, respectively), with low unspecific toxicity towards Vero cells. Compound 36 was also active against a metronidazole-resistant isolate (IC50 = 9.11 μM) and can thus be considered a good prototype for the development of drugs directed to T. vaginalis resistant to 5-nitroimidazoles., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

In an ongoing effort to discover an effective, topical, dual-function, non-surfactant contraceptive vaginal microbicide, a novel series of 2,2'-disulfanediylbis(3-(substituted-1-yl)propane-2,1-diyl) disubstituted-1-carbodithioates were designed by using a bioisosterism approach. Thirty-three compounds were synthesized, and interestingly, most demonstrated multiple activities: they were found to be spermicidal at a minimal effective concentration of 1-0.001 %, trichomonacidal against drug-susceptible and resistant Trichomonas strains at minimal inhibitory concentration (MIC) ranges of 10.81-377.64 and 10.81-754.14 μM, respectively, and fungicidal at MIC 7.93-86.50 μM. These compounds were also found to be non-cytotoxic to human cervical (HeLa) epithelial cells and vaginal microflora (Lactobacilli) in vitro. The most promising compound, 2,2'-disulfanediylbis(3-(pyrrolidin-1-yl)propane-2,1-diyl)dipyrrolidine-1-carbodithioate (5), exhibited spermicidal activity 15-fold higher than that of the marketed spermicide Nonoxynol-9 (N-9) and also demonstrated microbicidal potency. To identify common structural features required for spermicidal activity, a 3D-QSAR analysis was carried out, as well as in vivo efficacy studies and fluorescent labeling studies to determine the biological targets of compound 5., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Artemisia absinthium is an aromatic and medicinal plant of ethnopharmacological interest and it has been widely studied. The use ofA. absinthium based on the collection of wild populations can result in variable compositions of the extracts and essential oils (EOs). The aim of this paper is the identification of the active components of the vapour pressure (VP) EO from a selected and cultivated A. absinthium Spanish population (T2-11) against two parasitic protozoa with different metabolic pathways: Trypanosoma cruzi and Trichomonas vaginalis. VP showed activity on both parasites at the highest concentrations. The chromatographic fractionation of the VP T2-11 resulted in nine fractions (VLC1-9). The chemical composition of the fractions and the antiparasitic effects of fractions and their main compounds suggest that the activity of the VP is related with the presence of trans-caryophyllene and dihydrochamazulene (main components of fractions VLC1 and VLC2 respectively). Additionally, the cytotoxicity of VP and fractions has been tested on several tumour and no tumour human cell lines. Fractions VLC1 and VLC2 were not cytotoxic against the nontumoural cell line HS5, suggesting selective antiparasitic activity for these two fractions. The VP and fractions inhibited the growth of human tumour cell lines in a dose-dependent manner.

Trichomonas gallinae , the cause of avian trichomonosis, is most commonly found in the order Columbiformes. Racing pigeons are often treated preventively with nitro-imidazoles, which could result in the emergence of resistant isolates, and these isolates can be a threat to wildlife when exchanges occur. The sequence type of 16 T. gallinae isolates obtained from racing pigeons and 15 isolates from wild pigeons was determined based on the ITS1/5.8S rRNA/ITS2 region sequence. In addition, the resistance profiles of these isolates against 5 different nitro-imidazoles (metronidazole, dimetridazole, ronidazole, tinidazole, and carnidazole) were determined. Two different Trichomonas sequence types were isolated. Sequence type A isolates were recovered from racing and wild pigeons, in contrast to sequence type B, which was only isolated from wild pigeons. Isolates with sequence type B were all susceptible to the tested nitro-imidazoles, except for tinidazole resistance in 3 isolates. Resistance to the nitro-imidazoles was observed more frequently in isolates obtained from racing pigeons than from wild pigeons, with most isolates belonging to sequence type A. A higher percentage of the sequence type A isolated from racing pigeons, in comparison with those isolated from the wild pigeons, were resistant to the nitro-imidazoles and displayed higher mean lethal concentration (MLC) values. Two isolates belonging to sequence type A, 1 recovered from a racing pigeon and 1 from a wild pigeon, displayed a similar resistance pattern, suggesting a potential exchange of resistant isolates between racing pigeons and wild pigeons.

1-Substituted piperazinecarbodithioates were obtained by an unusual removal of CS2 in benzyl substituted dithiocarbamate derivatives under acid and basic conditions during design and synthesis of 1,4-(disubstituted)piperazinedicarbodithioates as double edged spermicides. A plausible mechanism for CS2 removal has been proposed. All synthesized compounds were subjected to spermicidal, antitrichomonal and antifungal activities. Twenty-one compounds irreversibly immobilized 100% sperm (MEC, 0.06-31.6 mM) while seven compounds exhibited multiple activities. Benzyl 4-(2-(piperidin-1-yl)ethyl) piperazine-1-(carbodithioate) (18) and 1-benzyl 4-(2-(piperidin-1-yl)ethyl)piperazine-1,4-bis(carbodithioate) (24) exhibited appreciable spermicidal (MEC, 0.07 and 0.06 mM), antifungal (MIC, 0.069-0.14 and >0.11 mM) and antitrichomonal (MIC, 1.38 and 0.14 mM) activities. The probable mode of action of these compounds seems to be through sulfhydryl binding which was confirmed by fluorescence labeling of sperm thiols.

Trichomonas gallinae is the causative agent of canker in pigeon. This work was carried out to investigate in the vitro and in vivo efficacy of aqueous water extract of garlic (AGE) on the growth of T. gallinae infecting pigeons compared to those of metronidazole (MTZ). MTZ and AGE were added, at different concentrations, to glucose-serum broth medium containing 1 × 10(4) trophozoites/ml. In the in vivo experiment, 48 squabs were grouped into four groups. The first group (gr. I) was not infected and not treated. Each squab of the other group was infected with 1 × 10(4) trophozoites. The second group (gr. II) was infected and not treated. On day 0, the third group (gr. III) was treated with MTZ (50 mg/kg BW) and the fourth group (gr. IV) was treated with AGE (200 mg/kg BW) for seven successive days in drinking water. In vitro study revealed that the MLC, 24, 48, and 72 h post treatment were 50, 25, and 12.5 μg/ml, respectively, for MTZ and 75, 50, and 50 mg/ml, respectively, for AGE. Garlic (200 mg/kg BW) had the highest antitrichomonal effect and shortened course of treatment of pigeons from 7 days in gr. III to 5 days. Squabs in gr. II suffered from macrocytic hypochromic anemia, whereas squabs in grs. III and IV showed normal blood pictures. Serum total protein, albumin, and globulin were increased, whereas AST, ALT, and the total cholesterol were decreased in grs. III and IV when compared to those of gr. II. Pigeons protected with AGE showed increased body weight and reduced mortality percentage than the other groups. Our results indicated that garlic may be a promising phytotherapeutic agent for protection against trichomoniasis in pigeons.

Trichomonas gallinae is a protozoan parasite commonly found in columbids, passerines, and raptors. In passerines and columbids, trichomonosis causes significant morbidity and mortality associated with contaminated bird feeders and waters. However, there has been little work on the persistence of T. gallinae in water to determine if artificial waters are a likely source of infection for naive birds. To examine drinking water as a source of T. gallinae transmission, we inoculated 1 x 10(6) trichomonads into containers with 500 ml of either distilled or chlorinated water. In addition, we inoculated the same number of trichomonads in distilled or chlorinated water contaminated with 15 g organic matter. Aliquots of 0.5 ml were collected from each container at 0, 0.5, 1, 5, 10, or 20 min; inoculated into a Trichomonas culture packet; and incubated at 37 C for 6 days. Survival was best in the presence of organic matter, with either distilled or chlorinated water. Uncontaminated chlorinated water did not allow survival at any sampling period.

In our presented research, we made an attempt to predict the 3D model for cysteine synthase (A2GMG5_TRIVA) using homology-modeling approaches. To investigate deeper into the predicted structure, we further performed a molecular dynamics simulation for 10 ns and calculated several supporting analysis for structural properties such as RMSF, radius of gyration, and the total energy calculation to support the predicted structured model of cysteine synthase. The present findings led us to conclude that the proposed model is stereochemically stable. The overall PROCHECK G factor for the homology-modeled structure was -0.04. On the basis of the virtual screening for cysteine synthase against the NCI subset II molecule, we present the molecule 1-N, 4-N-bis [3-(1H-benzimidazol-2-yl) phenyl] benzene-1,4-dicarboxamide (ZINC01690699) having the minimum energy score (-13.0 Kcal/Mol) and a log P value of 6 as a potential inhibitory molecule used to inhibit the growth of T. vaginalis infection.

Trichomonas gallinae is a flagellated protozoon which parasitizes in the upper digestive tract of different birds, especially columbiformes (doves and pigeons) and falconiformes. The parasite is also a common inhabitant of the crop of psittacine birds and is frequently detected in budgerigars. The lesions associated with T. gallinae infection of the upper digestive tract range from mild inflammation of the mucosa to large caseous lesions that block the lumen of the oesophagus. Nitroimidazoles are considered to be the drugs of choice for the treatment of trichomonosis. However, only a few studies report the existence of resistant strains of T. gallinae to these drugs. Thus, in the present investigation cloned cultures of T. gallinae obtained from budgerigars and pigeons were analysed for the first time for their in vitro susceptibilities against four 5´-nitroimidazole derivates, including metronidazole, dimetridazole, ronidazole and ornidazole. Significantly different minimal lethal concentrations (MLCs) were observed for them against all four drugs. The lowest MLCs revealed the Trichomonas isolates obtained from two budgerigars, ranging from 2.0 ± 0.3 to 3.0 ± 0.7 μg/ml for metronidazole and dimetridazole, and from 2.0 ± 0.6 to 6.7 ± 1.7 μg/ml for ornidazole and ronidazole. Contrary to this, the highest MLCs were recorded for one Trichomonas isolate obtained from a pigeon, ranging from 83.3 ± 6.7 (for dimetridazole and ronidazole) to 103.3 ± 3.3 μg/ml (for metronidazole and ornidazole). The data obtained for the resistance testing were further compared with already available genetic data of the small subunit rRNA gene sequences and ITS-1, 5.8S rRNA and ITS-2 sequences, indicating a certain correlation between in vitro results and strain relationships., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Many drugs with very different affinity to a large number of receptors are described. Thus, in this work, we selected drug-target pairs (DTPs/nDTPs) of drugs with high affinity/nonaffinity for different targets. Quantitative structure-activity relationship (QSAR) models become a very useful tool in this context because they substantially reduce time and resource-consuming experiments. Unfortunately, most QSAR models predict activity against only one protein target and/or they have not been implemented on a public Web server yet, freely available online to the scientific community. To solve this problem, we developed a multitarget QSAR (mt-QSAR) classifier combining the MARCH-INSIDE software for the calculation of the structural parameters of drug and target with the linear discriminant analysis (LDA) method in order to seek the best model. The accuracy of the best LDA model was 94.4% (3,859/4,086 cases) for training and 94.9% (1,909/2,012 cases) for the external validation series. In addition, we implemented the model into the Web portal Bio-AIMS as an online server entitled MARCH-INSIDE Nested Drug-Bank Exploration & Screening Tool (MIND-BEST), located at http://miaja.tic.udc.es/Bio-AIMS/MIND-BEST.php . This online tool is based on PHP/HTML/Python and MARCH-INSIDE routines. Finally, we illustrated two practical uses of this server with two different experiments. In experiment 1, we report for the first time a MIND-BEST prediction, synthesis, characterization, and MAO-A and MAO-B pharmacological assay of eight rasagiline derivatives, promising for anti-Parkinson drug design. In experiment 2, we report sampling, parasite culture, sample preparation, 2-DE, MALDI-TOF and -TOF/TOF MS, MASCOT search, 3D structure modeling with LOMETS, and MIND-BEST prediction for different peptides as new protein of the found in the proteome of the bird parasite Trichomonas gallinae, which is promising for antiparasite drug targets discovery.

Eugenia uniflora, used ethnomedically in some tropical countries as an anti-infective, has shown anti-malarial and anti-trypanocidal activities. Therefore using bioactivity guided fractionation, anti-trichomonal activity of E. uniflora leaf was investigated. Anti-trichomonal activities of leaf methanol extract and its fractions against Trichomonas gallinae as well as their cytotoxicities using an in vitro haemaglutination assay were determined. Anti-trichomonacidal activities of the extract improved on purification up to a stage. Subfractions E(2-5) had LC(50) and LC(90) values of 4.77 - 5.28, 18.49 - 25.00 and 4.53 - 5.18, 18.32 - 19.07 µg/ml at 24 and 48 hrs, respectively that were better than those of metronidazole. Further purification of E(2-5) led to loss of activity suggesting that the active components were probably working synergistically and additively. Demonstration of low haemaglutination titre values of 0.00 - 5.33 by methanolic extract and its partition fractions suggested their low toxicity profile. The established safety of the leaf indicated that its anti-trichomonal activity was not due to non-specific cytotoxicity, hence could be used in ethnomedicine as an anti-trichomonal agent.

The active ingredient of Huyinling, a combination of Chinese traditional medicine, was extracted by five different ethanol concentrations (40%-80%). There were seven groups named as five Huyinling ethanol extract groups (40%, 50%, 60%, 70%, and 80%), metronidazole group and blank control. Each Huyinling ethanol extract group was further divided into five subgroups with final concentration of 6.25, 12.5, 25, 50, and 100 mg/ml, respectively. Metronidazole group was given 10 microg/ml of the drug. Each group had 4 wells with 125 microl T. tenax(2 x 10(5)/ml). At 12 h, 24 h and 48 h after drug treatment, the anti-T. tenax effect of Huyinling ethanol extract was tested by microscope counting method. At 24 h the effect of Huyinling on T. tenax was examined with methyl thiazolyl tetrazolium (MTl) assay. The results showed that the higher concentration of Huyinling ethanol extract, the better effect on anti-T. tenax. 60% Huyinling ethanol extract group with concentrations of 6.25 mg/ml and 12.5 mg/ml showed higher anti-T. tenax effect than other groups (P < 0.01). The ethanol extract of Huyinling granules has a remarkable effect on T. tenax, and among the groups, 60% ethanol extract shows the best anti-T. tenax activity.

The aim of this study was to evaluate the biological activity of nine dermaseptin-S1 (DRS-S1) derivatives (synthesized by solid-phase methods and purified) against different pathogens causing genital infections (Trichomonas vaginalis, Herpes simplex virus, Papillomavirus). The in vitro activity on T. vaginalis was determined by counting the protozoon in a hemocytometer after vital staining with trypan blue; antiviral activity of the compounds was tested on monolayers of Vero cells for Herpes simplex virus-1 (GFP) and on 293TT cells for human papillomavirus (HPV-16) pseudovirions (GFP). The cytotoxicity of the derivatives was assessed by evaluating both the hemolytic activity and the effect on Vero and 293TT cells. The DRS-S1 longer peptides demonstrated a superior activity on T. vaginalis but also a certain cytopathic effect. The compounds with 29 amino acids exhibited activity against the two viruses tested at concentrations not toxic to cells. The results obtained show that some of the synthetic peptides assessed have inhibitory activity against the pathogens tested, indicating a potential for the development of new molecules for use as topical microbicides to prevent the sexual transmission of microorganisms.

The parasites Tritrichomonas foetus and Trichomonas gallinae present veterinary and economic importance since they cause bovine and avian trichomonosis, respectively. The absence of a specific treatment and the necessity of effective and safe drugs against these etiologic agents have stimulated the search for new antiprotozoal drugs with high activity, low toxicity to the animal, and low cost. Screening of potential antiprotozoal molecules is currently a common practice and different kinds of organic solvents and surfactant vehicles are used, since many bioactive compounds have low water solubility. Thus, it is important to determine the toxicity and to provide the minimal inhibitory concentration (MIC) values of the most common solubilization vehicles used in biological activity in vitro evaluation: ethanol, methanol, isopropanol, acetone, DMSO, tween 20 and tween 80. The assays were conducted employing the resazurin microtiter assay, which demonstrated a rapid, safe, and quantitative method for the in vitro determination of T. foetus and T. gallinae trophozoites viability. In summary, all solvents and surfactants, except ethanol, could be used in cytotoxicity assays against T. foetus, and acetone, tween 20 and tween 80 are the preferential vehicles for in vitro analysis of potential bioactive compounds against T. gallinae, though these must be used with caution.

Ethnopharmacological Relevance: Clausena lansium (Fool's Curry Leaf) is used for various ethnomedical conditions in some countries, including bronchitis, malaria, viral hepatitis, acute and chronic gastro-intestinal inflammation, and as a spicy substitute of the popular Curry leaf tree (Murraya koenigii)., Aim of the Study: This study was to evaluate the ethnomedical uses of the stem bark in inflammatory conditions, hepatotoxicity and to determine the anti-diabetic and anti-trichomonal properties of the plant., Materials and Method: Anti-trichomonal, in vivo and in vitro antidiabetic and insulin stimulating, anti-inflammatory, hepatoprotective and anti-oxidant activities using Trichomonas gallinae, glucose loaded rats and in vitro insulin secreting cell line (INS-1 cell), carrageenin-induced rat paw oedema, CCl(4)-induced hepatotoxicity and DPPH scavenging ability methods respectively for the extracts and some isolates were determined., Results: A dichloromethane extract was superior over methanolic extract with respect to an anti-trichomonal activity which was measured after 24 and 48 h. The isolated compounds imperatorin and 3-formylcarbazole had the main anti-trichomonal activity (LC(50)s of 6.0, 3.0 and 3.6, 9.7 microg/mL after 24 and 48 h, respectively). Methanolic extract (100 mg/kg) induced maximum and significant (p<0.05) anti-hyperglycaemic activity of 15.8% at 30 min and a 38.5% increase in plasma insulin at 60 min, compared to control. The increase in plasma insulin after 60 min, compared to 0 min, was 62.0% (p<0.05). The significant 174.6% increase of insulin release from INS-1 cells (in vitro) at 0.1 mg/ml indicates that it mediates its antidiabetic action mainly by stimulating insulin release. Imperatorin and chalepin were the major active constituents increasing in vitro insulin release to 170.3 and 137.9%, respectively. 100 mg/kg of the methanolic extract produced an anti-inflammatory activity after 4 h. A sedative effect was not observed. 100 and 200 mg/kg of methanolic extract administered i.p., reduced CCl4-induced hepatotoxicity firstly by 5.3 and 8.4% reduction in phenobarbitone-sleeping time respectively, secondly by reversing the reduction in serum liver proteins by 7.0-8.8%, serum AST, ALT and ALP activities by 27.7-107.9% and thirdly by diminishing increased values of plasma AST, ALT and ALP activities by 13.2-83.8%. The extract exhibited antioxidant activities., Conclusion: The hepatoprotective activity of C. lansium is partly due to its anti-oxidant and anti-inflammatory properties and confirms its folkloric use in the treatment of gastro-intestinal inflammation, bronchitis and hepatitis. In addition the use of C. lansium stem bark would be useful in diabetes and trichomoniasis.

Infections with Giardia lamblia, Entamoeba histolytica, and Trichomonas vaginalis, which cause diarrhea, dysentery, and vaginitis, respectively, are each treated with metronidazole. Here we show that Giardia, Entamoeba, and Trichomonas have oxygen-insensitive nitroreductase (ntr) genes which are homologous to those genes that have nonsense mutations in metronidazole-resistant Helicobacter pylori isolates. Entamoeba and Trichomonas also have nim genes which are homologous to those genes expressed in metronidazole-resistant Bacteroides fragilis isolates. Recombinant Giardia, Entamoeba, and Trichomonas nitroreductases used NADH rather than the NADPH used by Helicobacter, and two recombinant Entamoeba nitroreductases increased the metronidazole sensitivity of transformed Escherichia coli strains. Conversely, the recombinant nitroimidazole reductases (NIMs) of Entamoeba and Trichmonas conferred very strong metronidazole resistance to transformed bacteria. The Ehntr1 gene of the genome project HM-1:IMSS strain of Entamoeba histolytica had a nonsense mutation, and the same nonsense mutation was present in 3 of 22 clinical isolates of Entamoeba. While ntr and nim mRNAs were variably expressed by cultured Entamoeba and Trichomonas isolates, there was no relationship to metronidazole sensitivity. We conclude that microaerophilic protists have bacterium-like enzymes capable of activating metronidazole (nitroreductases) and inactivating metronidazole (NIMs). While Entamoeba and Trichomonas displayed some of the changes (nonsense mutations and gene overexpression) associated with metronidazole resistance in bacteria, these changes did not confer metronidazole resistance to the microaerophilic protists examined here.

Here we described an nucleoside triphosphate diphosphohydrolase (NTPDase) activity in living trophozoites of Trichomonas gallinae. The enzyme hydrolyzes a variety of purine and pyrimidine nucleoside di- and triphosphates in an optimum pH range of 6.0-8.0. This enzyme activity was activated by high concentrations of divalent cations, such as calcium and magnesium. Contaminant activities were ruled out because the enzyme was not inhibited by classical inhibitors of ATPases (ouabain, 5.0 mM sodium azide, oligomycin) and alkaline phosphatases (levamisole). A significant inhibition of ATP hydrolysis (38%) was observed in the presence of 20 mM sodium azide. Sodium orthovanadate inhibited ATP and ADP hydrolysis (24% and 78%), respectively. The apparent K(M) (Michaelis constant) values were 667.62+/-13 microM for ATP and 125+/-5.3 microM for ADP. V(max) (maximum velocity) values were 0.44+/-0.007 nmol Pi min(-1) per 10(6) trichomonads and 0.91+/-0.12 nmol Pi min(-1) per 10(6) trichomonads for ATP and ADP, respectively. Moreover, we showed a marked decrease in ATP, ADP and AMP hydrolysis when the parasites were grown in the presence of penicillin and streptomycin. The existence of an NTPDase activity in T. gallinae may be involved in pathogenicity, protecting the parasite from the cytolytic effects of the extracellular nucleotides.

Aim of the Study: The ethanolic stem bark extract of Harungana madagascariensis (Hypericaceae), (Choisy) Poir were evaluated for their activities on Trichomonas gallinae (Rivolta) Stabler isolated from the pigeon (Columba livia). It was also tested for their anti-malarial activity on N67 Plasmodium yoelii nigeriensis (in vivo) in mice and on Plasmodium falciparum isolates in vitro., Materials and Methods: The anti-trichomonal screening was performed in vitro using Trichomonas gallinae culture. The minimum lethal concentration (MLC) is the lowest concentration of the test extract in which no motile organisms were observed. The anti-malarial effects were determined in-vivo for suppressive, curative and prophylactic activities in mice receiving a standard inoculum size of 1 x 10(7) (0.2 ml) infected erythrocytes of Plasmodium yoelii nigeriensis intraperitoneally, and the in vitro was performed against 3 isolates of Plasmodium falciparum in a candle jar procedures., Results: The IC(50) of the extract and metronidazole (MDZ) (Flagyl) on Trichomonas gallinae at 48 h are 187 and 1.56 microg/ml. The IC(50) of the extract, chloroquine (CQ) and artemether (ART) on Plasmodium falciparum are between 0.052 and 0.517 microg/ml for the extract and 0.021 and 0.0412 microg/ml for ART and CQ, respectively. The actions of the extract in in vivo study on Plasmodium yoelii nigeriensis showed that in both suppressive and prophylactic tests the percentages chemo-suppressive were between 28.6-44.8% and 30.2-78.2% respectively, while only 80 mg/kg of the extract reduced the parasitaemia level when compared to the control and the standard drugs in curative test., Conclusions: Harungana madagascariensis stem bark extract therefore exhibited significant anti-protozoan effects against Trichomonas and Plasmodium both in vivo and in vitro.

Hydrogenosomes are spherical or slightly elongated organelles found in non-mitochondrial organisms. In Trichomonas hydrogenosomes measure between 200 to 500 nm, but under drug treatment they can reach 2 microm. Like mitochondria hydrogenosomes: (1) are surrounded by two closely apposed membranes and present a granular matrix: (2) divide in three different ways: segmentation, partition and the heart form; (3) they may divide at any phase of the cell cycle; (4) produce ATP; (5) participate in the metabolism of pyruvate formed during glycolysis; (6) are the site of molecular hydrogen formation; (7) present a relationship with the endoplasmic reticulum; (8) incorporate calcium; (9) import proteins post-translationally; (10) present cardiolipin. However, there are differences, such as: (1) absence of genetic material, at least in trichomonas; (2) lack a respiratory chain and cytochromes; (3) absence of the F(0)-F(1) ATPase; (4) absence of the tricarboxylic acid cycle; (5) lack of oxidative phosphorylation; (6) presence of peripheral vesicles. Hydrogenosomes are considered an excellent drug target since their metabolic pathway is distinct from those found in mitochondria and thus medicines directed to these organelles will probably not affect the host-cell. The main drug used against trichomonads is metronidazole, although other drugs such as beta-Lapachone, colchicine, Taxol, nocodazole, griseofulvin, cytochalasins, hydroxyurea, among others, have been used in trichomonad studies, showing: (1) flagella internalization forming pseudocyst; (2) dysfunctional hydrogenosomes; (3) hydrogenosomes with abnormal sizes and shapes and with an electron dense deposit called nucleoid; (4) intense autophagy in which hydrogenosomes are removed and further digested in lysosomes.

The presence of iron in the extracellular medium is essential for both in vivo and in vitro survival of pathogenic microorganisms, including Trichomonas vaginalis and Tritrichomonas foetus. In these parasites, iron is directly involved in the proliferation, protein expression and activation of critical enzymes. The purpose of this study was to investigate the role of iron in ecto-ATPase, ecto-phophatase and secreted phosphatase activities of these trichomonads. We observed that trichomonads grown in iron-depleted medium exhibited a remarkable decrease in both ecto-ATPase and ecto-phosphatase activities, when compared to those cultivated under control conditions (iron-rich medium). Furthermore, parasites grown in iron-depleted medium restored their enzyme activities when they were re-inoculated into fresh iron-rich medium. We demonstrated that modulation of ecto-phosphohydrolase activities is due neither to enzyme-iron nor to substrate-iron complex formation, since iron addition directly to the medium where the enzymatic reactions occurred did not alter their activities. Previously, we had reported that a fresh clinical isolate of T. vaginalis was much more cytotoxic to epithelial cell monolayers than a long-term cultured one. In this study we witnessed that the fresh isolate of T. vaginalis presented higher activities to all herein investigated enzymes than the long-term cultured one. Altogether, our data clearly point out that iron has a pivotal role in the expression of phosphohydrolases in both trichomonads.

Tritrichomonas foetus is an amitochondriate parasite that possesses hydrogenosomes, unusual anerobic energy-producing organelles. In these organisms the "mitochondrial cell death machinery" is supposed to be absent, and the mechanisms that lead to cell demise remain to be elucidated. The presence of a cell death program in trichomonads has already been reported, suggesting the existence of a caspase-like execution pathway in such organisms. Here we demonstrate the alterations provoked by the fungicide griseofulvin and raise the possibility that other cell death pathways may exist in T. foetus. Dramatic changes in trichomonads morphology are presented after griseofulvin treatment, such as intense plasma membrane and nuclear envelope blebbing, nucleus fragmentation, and an abnormal number of oversized vacuoles. One important finding was the exposition of phosphatidylserine (PS) in the outer leaflet of the plasma membrane in cells after drug treatment, and also the presence of a high amount of misshapen flagella and tubulin precipitates as vacuolar contents, suggesting an autophagic process of abnormal cellular elements. Interestingly, immunoreactivity for activated caspase-3 was not detected during griseofulvin treatment, a finding distinct from the observed when this cell was treated with H(2)O(2). The possibility of the existence of different pathways to cell death in trichomonads is discussed.

The methanolic extract of Murraya koenigii leaf was screened for toxicological and biochemical effects on rats because of the folkloric uses as an anti-dysentery and anti-diabetes. The extract was moderately toxic (LD(50)=316.23 mg/kg body weight) to rats and had appreciable effect on the liver and kidney at higher doses leading to liver inflammation. It had little or no effect on haematology and relative organ weight of lungs, heart and spleen. Acute doses (500 mg/kg) reduced significantly serum globulin, albumin, urea, glucose, total protein, aspartate transaminase (AST), and increased cholesterol and alanine transaminase (ALT) indicating hepatic injury. However, chronic administration for 14 days gave a significant (p<0.05) reduction in the serum cholesterol, glucose, urea, bilirubin, ALT and AST showing that the plant has hypoglycaemic and hepatoprotective effects after prolonged use. The activity demonstrated by some of the isolated carbazole alkaloids and their derivatives against Trichomonas gallinae confirmed that the anti-trichomonal activity of the leaf may be due to its carbazole alkaloids. The order of activity was C(18)>C(23)>C(13). Girinimbine and girinimbilol with IC(50) values of 1.08 and 1.20 microg/ml were the most active. Acetylation of girinimbilol and mahanimbilol improved their activities to 0.60 and 1.08 microg/ml.

Dorstenia barteri and D. convexa extracts and some isolated components of the former were investigated for effectiveness against Trichomonas gallinarum and compared with quercetin and quercitrin. The antioxidant activity of the extracts/compounds was also determined. The minimum lethal concentrations (MLCs) for the extract of D. barteri leaves and twigs at 24 h were found to be 15.625 and 15.625 microg/ml, respectively. However, the MLCs of the leaf and twig extract of D. convexa were 125 and 437.5 microg/ml, respectively. The prenylated and geranylated chalcones were as active as the prenylated flavones, 6-prenylapigenin and the diprenylated derivative 6,8-diprenyleridictyol. The order of the antitrichomonal activity of the compounds at 24 h was: quercetin (0.121 microg/ml) > quercitrin (0.244 microg/ml) > or = bartericin B (0.244 microg/ml) > bartericin A (0.73 microg/ml) > stigmasterol (0.98 microg/ml) > 6,8-diprenyleridictyol = isobavachalcone = dorsmanin F (31.25 microg/ml). D. barteri extracts, quercitrin, and bartericin A, and the prenylated flavonoids had potent antioxidant properties. The twig extract of D. barteri was more potent than the leaf extract. Moderate (EC50 >50 microg/ml) and high (EC50 <50 microg/ml) antioxidant activities were detected in the leaf and twig extracts of D. barteri and the prenylated flavonoids. Prenylated flavonoids and the isolated compounds with antioxidant properties described here may account for the anti-inflammatory action of these extracts. The antitrichomonal and antioxidant activities shown by the extracts and compounds in this study are consistent with the ethnomedicinal and local use of the Dorstenia species studied.

Ronidazol is often used in racing pigeons for the treatment of Trichomonas infections and diseases. Therefore, in this study, the compatibility of the drug was examined by oral application over 7 days. For this purpose a randomized blind study was performed using four different groups (control group, 10 mg = therapy-group, 20 mg = double-dose-group and 40 mg = high-dose-group) of pigeons (Columba livia f. domestica) with 6 male and 6 female birds each. All birds were clinically healthy and between 6 and 12 weeks of age. The application of ronidazol at a dose of 10 mg/racing pigeon did show no side-effect within the duration of the study, e.g. no influence could be seen on clinical, haematological, blood-chemical and pathological parameters. Low-to middle-grade clinical alterations of the gastro-intestinal tract occurred in the high-dose group at day 6 and 7 of the application of the drug. Therefore a fourfold overdosing of ronidazol should be avoided.

The flagellate Trichomonas hominis is often identified in human diarrheic stools. Because of the fecal-oral transmission rout, infection with T. hominis is more frequently reported in children than in adults. Although infections with the trichomonads in some world regions are as often as with Giardia, no prevention and optimal treatment are defined. The purpose of our in vitro studies was to examine susceptibility of T. hominis to a newly synthesized imidazole derivative--1-metylo-2-(2,4-dinitrobenzylotio)-1H-imidazol--P27; in order to make a comparison between this new and previously known compounds, chlorhexidine and metronidazole were used. The protozoans derived from the diarrheic stool of adult patient were grown on the liquid Pahm medium and subcultured twice a week. Assays of trichomonad cultures were incubated with one of the following substances: chlorhexidine, metronidazole or P27. For each compound, two different concentrations were applied. After 24h exposition, an antitrichomonal effect of the above substances was assessed, namely a quantity of the surviving trichomonads was microscopically determined and compared with that observed in control cultures. The protozoans showed different susceptibility, depending on kind and concentration of tested compound. In comparison to the control cultures, the reduction in number of surviving protozoans appeared in the assays with metronidazole, chlorhexidine and P27 (to 63%, 52% and 8.7%, respectively). The highest in vitro susceptibility of T. hominis was revealed to a new imidazole derivative P27. The obtained results allow us to suppose that the further studies in this field will be very helpful for explaining the mechanisms of the antitrichomonal activity of the tested compounds as well as for assessment of the influence of various abiotic factors.

Treatment of cultures of Tritrichomonas foetus with 4 mM hydroxyurea (HU), a known DNA synthesis inhibitor, induced pseudocyst formation and caused a mitotic burst. An hour after drug release there was a characteristic, synchronous burst of cell division. T. foetus culture was arrested in the G2/M phase. The synchrony index varied from 66% to 69%. The synchrony was maintained for several cell cycles, even in thawed cultures which had been frozen for storage in liquid nitrogen. The synchronized cells were analyzed by light and scanning electron microscopy, as well by flow cytometry.

The situation regarding the treatment of human Giardia and Trichomonas infections and the intestinal and tissue stages of Entamoeba histolytica with metronidazole and other 5-nitroimidazoles is currently satisfactory (Table 1; Mehlhorn 2000). Following correct and rapid diagnosis, the parasites are eliminated reliably and completely. The situation in cases of infection with Acanthamoeba (often involving the eyes) or with Naegleria (often involving the brain) is serious, however. In both cases, there is no drug of choice available. Treatment consists of relieving the symptoms and/or preventing local degeneration.

We describe an experimental system for the study of rapid and reversible formation of pseudocysts, which are spherical forms that lack a true cyst wall, by Tritrichomonas foetus, a trichomonad parasite of the bovine genitourinary tract. It highlights the dynamics of the plasma membrane and cytoskeleton of this parasite, which is perpetually devoid of any sort of protective cell wall, and can reflect a responsive survival mechanism. We have found that cooling of axenic cultures of T. foetus from their normal 37 degrees C to below about 16 degrees C can trigger pseudocyst formation. The three anterior flagella and the single recurrent flagellum can be fully internalized within 1 3 min at 37 degrees C, with the axonemes and flagellar membranes remaining intact within the cell body. Electron microscopy confirms that the internalized flagella are surrounded by a separate membrane. At 37 degrees C the internalized flagella can resume beating movements and become externalized as quickly as within 10 min. We have begun to elucidate the mechanisms of this unusual phenomenon, characterizing its temperature dependence and exploring the effects of agents that interfere with various aspects of the cytoskeleton, phagocytosis, endocytosis, and exocytosis.

Acute renal failure was diagnosed in 4 cats receiving paromomycin orally for treatment of infectious enteritis. All 4 cats responded to fluid therapy and recovered normal or near-normal renal function; however, 3 of the cats subsequently became deaf and developed cataracts. Toxicoses were attributed to a combination of an excessive dosage of paromomycin and absorption of the drug across injured intestinal mucosal epithelium. Pharmacokinetic studies are needed to further define the disposition of paromomycin after oral administration to cats.

Ethyl ether, ethyl acetate and n.butanol extracts of Cotula cinerea L. were tested for their antiprotozoal activity against two species of Trichomonas: Trichomonas intestinalis and Trichomonas vaginalis. It has been found that the growth of both Trichomonas was significantly inhibited.

The extracts of six plants selected on the basis of folk-medicine reports were examined for their antibacterial effects against eight pathogenic bacteria. The results showed that n-butanol extract of Calotropis procera proved to be the most effective against the bacteria tested using the paper disc diffusion method. The antiprotozoal activity was also examined and showed that ethyl ether extract of Sium nodiflorum exhibits a parasiticidal effect against Trichomonas intestinalis and vaginalis.

The process of autophagy was studied in Tritrichomonas foetus under serum deprivation, drug treatment (hydroxyurea, zinc sulfate), and also in normal conditions using routine electron microscopy, freeze-fracture, freeze-substitution, and enzyme cytochemistry. We also used gold particles conjugated with bovine albumin to better characterize the participation of lysosomes in the process of hydrogenosome degradation. Apparently normal hydrogenosomes and also giant, abnormal hydrogenosomes presenting internal membranes were seen in the autophagic process. The first event observed was the rough endoplasmic reticulum surrounding and enclosing the hydrogenosome, forming an isolation membrane. The hydrogenosomes were first sequestered from the remaining cytoplasm and then degraded within lysosomes. The autophagic vacuoles were limited by double or multiple concentric membranes and many contained recognizable hydrogenosomes, probably in the preliminary steps of degradation. Lysosomes seemed to fuse with autophagic vacuoles forming a degradative structure bound by a single membrane and containing hydrogenosomes in various stages of degeneration. Hydrogenosomes appeared partially degraded, forming hydrogenosomal remnants. It was observed that there is a removal of hydrogenosomes in normal cells and in cases of cell toxicity.

Seven gold complexes were prepared and investigated for biocidal activity against Gram-positive and -negative bacteria, fungi and protozoa. All of them were active against the tested microorganisms with the exception of Pseudomonas aeruginosa. In many, cases minimum inhibitory concentrations (MIC) were well below 1 microgram/ml. The activity is not simply related to the gold content, but also to the nature of both the phosphine and the aminothiol to which the metal is bound.

A study was carried out in order to establish the in vivo efficacy of two nitroimidazole drugs against the flagellate Trichomonas gallinae. The results obtained showed a high proportion of therapeutic failures. Thus, carnidazole and dimetridazole failed to eliminate infection in 13 of 17 and 20 of 21 racing pigeons, respectively. The in vitro susceptibility of four T. gallinae isolates to five nitroimidazolic drugs, that is, carnidazole, dimetridazole, metronidazole, ornidazole and ronidazole, was also determined. Minimal lethal concentrations (MLCs) of these drugs were obtained. One of the isolates tested had already proved to be resistant in the first in vivo tests, while the other three had been obtained from wild birds. We were able to confirm in vitro the resistance of the racing pigeon isolate to all the nitroimidazole drugs tested. For carnidazole, dimetridazole, metronidazole and ornidazole the MLC ranged between 93.75-500 microg ml. Although ronidazole showed a greater potency than the other nitroimidazole derivatives against this isolate (MLC: 15.62-31.25 microg ml), 8-22 times more drug was necessary for efficacy against this isolate compared to the others. These other three parasite isolates proved to be sensitive to the five drugs tested (MLC: 0.97-7.81 microg ml).

Trichomonads are early-diverging eukaryotes that lack both mitochondria and peroxisomes. They do contain a double membrane-bound organelle, called the hydrogenosome, that metabolizes pyruvate and produces ATP. To address the origin and biological nature of hydrogenosomes, we have established an in vitro protein import assay. Using purified hydrogenosomes and radiolabeled hydrogenosomal precursor ferredoxin (pFd), we demonstrate that protein import requires intact organelles, ATP and N-ethylmaleimide-sensitive cytosolic factors. Protein import is also affected by high concentrations of the protonophore, m-chlorophenylhydrazone (CCCP). Binding and translocation of pFd into hydrogenosomes requires the presence of an eight amino acid N-terminal presequence that is similar to presequences found on all examined hydrogenosomal proteins. Upon import, pFd is processed to a size consistent with cleavage of the presequence. Mutation of a conserved leucine at position 2 in the presequence to a glycine disrupts import of pFd into the organelle. Interestingly, a comparison of hydrogenosomal and mitochondrial protein presequences reveals striking similarities. These data indicate that mechanisms underlying protein targeting and biogenesis of hydrogenosomes and mitochondria are similar, consistent with the notion that these two organelles arose from a common endosymbiont.

This work describes the synthesis of 4-amino-3-cinnolinecarboxamides, which were then hydrolyzed to corresponding 4-amino-3-cinnolinecarboxylic acids. Several compounds were tested for their antibacterial and antifungal activity, and for the central nervous system effect.