Structure of trichomonads as revealed by scanning electron microscopy.

A scanning electron microscope (SEM) study of Hypotrichomonas acosta (Moskowitz), Trichomonas vaginalis Donné, Pentatrichomonas hominis (Davaine), and Tritrichomonas foetus (Riedmüller) provided new information about the structure of the periflagellar canal; emergence of the flagella from the cell body; structure of the undulating membrane; and position, shape, and size of the pelta. Of special interest were the spatial relationships of the attached part of the recurrent flagellum and the accessory filament in Hypotrichomonas and in the members of Trichomonadinae, i.e. Trichomonas and Pentatrichomonas.     

Molecular phylogeny of parabasalids based on small subunit rRNA sequences, with emphasis on the Trichomonadinae subfamily

We determined small subunit ribosomal DNA sequences from three parabasalid species, Trichomitus batrachorum strain R105, Tetratrichomonas gallinarum, and Pentatrichomonas hominis belonging to the Trichomonadinae subfamily. Unrooted molecular phylogenetic trees inferred by distance, parsimony, and likelihood methods reveal four discrete clades among the parabasalids. The Trichomonadinae form a robust monophyletic group. Within this subfamily T. gallinarum is closely related to Trichomonas species as supported by morphological data, with P. hominis and Pseudotrypanosoma giganteum occupying basal positions. Our analysis does not place T. batrachorum within the Trichomonadinae. Trichomitus batrachorum (strains R105 and BUB) and Hypotrichomonas acosta form a well-separated cluster, suggesting the genus Trichomitus is polyphyletic. The emergence of T. batrachorum precedes the Trichomonadinae-Tritrichomonadinae dichotomy, emphasizing its pivotal evolutionary position among the Trichomonadidae. A third cluster unites the Devescovinidae and the Calonymphidae. The fourth clade contains the three hypermastigid sequences from the genus Trichonympha, which exhibit the earliest emergence among the parabasalids. The addition of these three new parabasalid species did not however resolve ambiguities regarding the relative branching order of the parabasalid clades. The phylogenetic positions of Tritrichomonas faetus, Monocercomonas sp., Dientamoeba fragilis, and the unidentified Reticulitermes flavipes gut symbiont 1 remain unclear.     

Electrophoretic analysis of soluble proteins and esterase, superoxide dismutase and acid phosphatase isoenzymes of members of the protozoan family trichomonadidae

Polyacrylamide gel electrophoresis was used to compare the proteins and isoenzymes of esterase, superoxide dismutase, and acid phosphatase in soluble, whole-cell extracts of four strains of Trichomonas vaginalis, two strains of Trichomonas gallinae, and one strain each of Tritrichomonas foetus, Tritrichomonas augusta, Tetratrichomonas gallinarum, and Pentatrichomonas hominis. Intraspecific, interspecific, and intergeneric differences were found in protein and isoenzyme profiles. At least four to seven isoenzymes were detected among the ten strains for each of the three enzymes studied. Each strain usually contained one or two isoenzymes of both esterase and acid phosphatase, and two or three isoenzymes of superoxide dismutase.     

Agar Techniques for Colonizing and Cloning Trichomonads

SYNOPSIS. Agar media have been used in plates, Burri tubes, and sealed slide preparations to grow trichomonads as clonal colonies. Periodic observation of slide-culture colonies confirmed their origin from single organisms as clones. Axenic cultures of Trichomonas vaginalis (3 strains), T. gallinae (2 strains), T. gallinarum (1 strain), Tritrichomonas augusta (5 strains), Trit. foetus (4 strains), Trit. suis (?) (6 strains), Pentatrichomonas hominis (1 strain), and an undescribed porcine form were used successfully. Urinary and vaginal specimens with T. vaginalis were also plated directly from patients. In all trials, organisms were recovered from colonies for broth culture and re-plating.
Colonies of the two strains of T. gallinae showed constant differences in their growth under the same conditions. Plated T. vaginalis have shown zones of growth inhibition in tests against drug-impregnated discs.     

Genetic differentiation and biochemical polymorphism among trichomonads

Isoenzyme electrophoresis was used to study levels of genetic differentiation among strains and clones of Trichomonas gallinae, Trichomonas vaginalis, Tritrichomonas foetus, Tetratrichomonas gallinarum, and Pentatrichomonas hominis. Strain variation was found within T. gallinae, T. vaginalis, and T. foetus, however, levels of enzyme polymorphism were greater in T. gallinae than in T. vaginalis or T. foetus. Isoenzyme genotypes were not a stable property of T. gallinae clones cultivated in vitro. Retrospective studies of T. gallinae SG and JB6 clones revealed that mutation occurred during in vitro cultivation. Heterozygotes of hexokinase-1 and phosphoglucomutase displayed 2 allomorphs in equal dosage, indicating that trichomonads are diploid for these protein loci. Phenetic clustering of the biochemical data suggests that levels of genetic divergence among the species studied are extensive.     

Cryopreservation of protozoan parasites

Conventional methods for the propagation and preservation of parasites in vivo or in vitro have some limitations, including the need for labor, initial isolation and loss of strains, bacterial, and fungal contamination, and changes in the original biological and metabolic characteristics. All these disadvantages are considerably reduced by cryopreservation. In this study, we examined the effects of various freezing conditions on the survival of several protozoan parasites after cryopreservation. The viability of Entamoeba histolytica was improved by seeding (p < 0.05, chi2 test), while this was not so effective for Trichomonas vaginalis. Of six cryoprotectants examined, dimethyl sulfoxide (Me(2)SO), and glycerol showed the strongest cryoprotective effects. The optimum conditions for using Me(2)SO were a concentration of 10% with no equilibration, and those for glycerol were a concentration of 15% with equilibration for 2h. The optimum cooling rate depended on the parasite species. Trypanosoma brucei gambiense and Leishmania amazonensis were successfully cryopreserved over a wide range of cooling rates, whereas the survival rates of E. histolytica, T. vaginalis, Pentatrichomonas hominis, and Blastocystis hominis were remarkably decreased when frozen at improper rates. Unlike the cooling rate, exposure of the protozoans to a rapid thawing method produced better motility for all parasites.     

中老年阴道炎患者阴道毛滴虫感染状况调查分析

目的:分析中老年阴道炎患者阴道毛滴虫感染情况,为中老年阴道炎的防治提供依据。方法:对2016年9月～2019年9月来我院就诊的中老年阴道炎患者的阴道分泌物进行阴道毛滴虫检查,同时通过问卷调查方法收集患者的病历资料,回收有效问卷200份,分析不同年龄、季节、职业、生活习惯、性生活情况患者的阴道毛滴虫感染状况。结果:中老年阴道炎患者阴道毛滴虫感染率为10.50%,其中45～50岁年龄段阴道炎患者阴道毛滴虫感染率最高,占19.15%,71～80岁年龄段阴道炎患者阴道毛滴虫感染率最低,占2.78%,不同年龄段阴道炎患者阴道毛滴虫感染率比较有统计学差异(P0.05)。春季、夏季阴道毛滴虫感染率显著高于秋季、冬季(P0.05)。牧民、农民阴道炎患者阴道毛滴虫感染率显著高于工人和公职人员的感染率(P0.05),牧民、农民阴道炎患者阴道毛滴虫感染率无明显差异(P0.05)。经常性清洁外阴的阴道炎患者阴道毛滴虫感染率显著低于非经常性清洁外阴的患者(P0.05)。有性生活阴道炎患者阴道毛滴虫感染率显著高于无性生活患者(P0.05),有性生活应用避孕套的阴道炎患者阴道毛滴虫感染率显著低于不应用避孕套患者(P0.05)。结论:中老年阴道炎患者阴道毛滴虫感染率较高,春季、夏季是阴道毛滴虫感染的高峰期,中年患者感染率高于老年患者,农民、牧民、服务人员和非经常性清洁外阴的患者阴道毛滴虫感染率较高,且有性生活没有应用避孕套者感染率更高,应做好以上高危人群的防治工作,以降低阴道毛滴虫的感染率。     

Pentatrichomonas hominis: purine salvage pathway

1. Pentatrichomonas hominis was found incapable of de novo synthesis of purines. 2. Pentatrichomonas hominis can salvage adenine, guanine, hypoxanthine, adenosine, guanosine and inosine, but not xanthine for the synthesis of nucleotides. 3. HPLC tracing of radiolabelled purines or purine nucleosides revealed that adenine, adenosine and hypoxanthine are incorporated into adenine nucleotides and IMP through a similar channel while guanine and guanosine are salvaged into guanine nucleotides via another route. There appears to be no direct interconversion between adenine and guanine nucleotides. Interconversion between AMP and IMP was observed. 4. Assays of purine salvage enzymes revealed that P. hominis possess adenosine kinase; adenosine, guanosine and inosine phosphotransferases; adenosine, guanosine and inosine phosphorylases and AMP deaminase.     

A Freeze-Fracture Electron Microscope Study of Trichomonas vaginalis Donné and Tritrichomonas foetus (Riedmüller)1

Two strains of Trichomonas vaginalis, JH162A, with low pathogenicity, and Balt 44, with high pathogenicity, as well as one highly pathogenic strain, KV-1, of Tritrichomonas foetus were studied by freeze-fracture electron microscopy. The protoplasmic faces (PFs) of the cell membranes of all three strains of both species had similar numbers of intramembranous particles (IMPs); however, the particles in the external faces (EFs) of these membranes were least abundant in Trichomonas vaginalis strain Balt 44 and most numerous in those of strain JH162A of this species. In Tritrichomonas foetus strain KV-1 the number of IMPs in the EF was close to but somewhat lower than that in the mild strain of the human urogenital trichomonad. In both species, the anterior, but not the recurrent, flagella had rosette-like formations, consisting of ～9 to 12 IMPs on both the PFs and EFs. The numbers and distribution of the rosettes appeared to vary among different flagella and in different areas of individual flagella of a single organism belonging to either species. The freeze-fracture electron micrographs provided a more complete understanding of the fine structure of undulating membranes of Trichomonadinae, as represented by Trichomonas vaginalis, and of Tritrichomonadinae (the Tritrichomonas augusta-type), as exemplified by Tritrichomonas foetus, than was gained from previous transmission and scanning electron microscope studies. Typically three longitudinal rows of IMPs on the PF of the recurrent flagellum of Trichomonas vaginalis were noted in the area of attachment of this flagellum to the undulating membrane. The functional aspects of the various structures and differences between certain organelles revealed in the two trichomonad species by the freeze-fracture method are discussed.     

Fine Structure of the Mastigont System in Tritrichomonas muris (Grassi)*

SYNOPSIS. Tritrichomonas muris shares many fine-structural details with the previously described members of the family Trichomonadidae, and especially with the organisms belonging to the subfamily Tritrichomonadinae. Among the features which T. muris has in common with all Trichomonadidae and in all probability with other Trichomonadida are the arrangement and structure of: the kinetosomes; many rootlet filaments, including the sigmoid filaments of kinetosome #2; the parabasal apparatus; and the pelta-axostyle complex. The structures which T. muris-type flagellates share with other Tritrichomonadinae, and especially with Tritrichomonas augusta-type species (including T. foetus), but not with Trichomonadinae that have been studied to date, are: the Type A costa; a comb-like structure, which appears to have replaced the costal base of Trichomonadinae and of Hypotrichomonas; the suprakinetosomal body, rudimentary in T. muris; and the infrakinetosomal body. The undulating membrane, like that of T. augusta-type organisms, consists of a proximal and a distal part. The proximal part, which contains the proximal marginal lamella, is less developed in T. muris than in T. augusta-type flagellates, being represented by a relatively low ridge for the entire length of the organism. The distal part of the membrane in T. muris, on the other hand, is more highly developed; it is a heavy cord, with a distal marginal lamella which consists of a large triangular organelle having a highly ordered structure and 2 less well defined cords distal to this organelle. The tubules of the recurrent flagellum occupy the area distal to the cords. The sigmoid filaments of kinetosome #2, unlike those of other Trichomonadidae examined to date, extend posteriorly to the peltar-axostylar junction; they seem to terminate within the cytoplasm near, but not connected to the axostyle. In addition to the Type A costa, there is a small rootlet filament, which appears to be homologous to the rudimentary costa noted in Hypotrichomonas. Some of the paraxostylar and paracostal granules consist of an outer, relatively dense layer and an inner “core” of moderate density; between the 2 there is a lucent ring. The discussion deals in some detail with the possible nature of the paraxostylar and paracostal granules in trichomonads. The taxonomic status of Tritrichomonas cricetus (Wantland) [Tritrichomonas criceti (Wantland) emend. Levine] and Trichomonas criceti Ray & Sen Gupta is discussed in an appendix; it is concluded that both of these names are synonyms of T. muris (Grassi).     

A freeze-fracture electron microscope study of Trichomonas vaginalis Donné and Tritrichomonas foetus (Riedmüller)

Two strains of Trichomonas vaginalis, JH162A , with low pathogenicity, and Balt 44, with high pathogenicity, as well as one highly pathogenic strain, KV-1, of Tritrichomonas foetus were studied by freeze-fracture electron microscopy. The protoplasmic faces ( PFs ) of the cell membranes of all three strains of both species had similar numbers of intramembranous particles (IMPs); however, the particles in the external faces (EFs) of these membranes were least abundant in Trichomonas vaginalis strain Balt 44 and most numerous in those of strain JH162A of this species. In Tritrichomonas foetus strain KV-1 the number of IMPs in the EF was close to but somewhat lower than that in the mild strain of the human urogenital trichomonad . In both species, the anterior, but not the recurrent, flagella had rosette-like formations, consisting of approximately 9 to 12 IMPs on both the PFs and EFs. The numbers and distribution of the rosettes appeared to vary among different flagella and in different areas of individual flagella of a single organism belonging to either species. The freeze-fracture electron micrographs provided a more complete understanding of the fine structure of undulating membranes of Trichomonadinae , as represented by Trichomonas vaginalis, and of Tritrichomonadinae (the Tritrichomonas augusta -type), as exemplified by Tritrichomonas foetus, than was gained from previous transmission and scanning electron microscope studies. Typically three longitudinal rows of IMPs on the PF of the recurrent flagellum of Trichomonas vaginalis were noted in the area of attachment of this flagellum to the undulating membrane. The functional aspects of the various structures and differences between certain organelles revealed in the two trichomonad species by the freeze-fracture method are discussed.     

Intestinal parasites in Kampuchea, Takeo Province

Fresh stool samples obtained from 1407 adult patients who sought treatment in Takeo province hospital and 332 Takeo preschool and school-age children from 3 to 18 years of age were examined for the presence of intestinal parasites using the technique of native preparation and the flotation method of Faust with subsequent staining with Lugol solution to demonstrate cysts. In hospital patients, a total of 13 protozoan and 9 helminth species were diagnosed. The prevalence of Entamoeba histolytica (cysts and trophozoites) was highest in the age group 15-18 years (18.3%), the peak prevalence of Gairdia lamblia (27.6%) occurred in children of the age group 6-9 years. The highest frequency distribution of Pentatrichomonas hominis (20.1%) was recorded in 3 to 5 years old, that of Enteromonas hominis (12.8%) in 6 to 9 years old. The predominant helminth was Ancylostoma duodenale, with the peak prevalence (65.2%) in patients older than 18 years, followed by Ascaris lumbricoides and Strongyloides stercoralis. Almost half of children patients under 6 was infected with at least two species of parasites, patients over 6 were infected simultaneously with two or more intestinal parasites in an absolute majority of cases. In Takeo preschool and school children the spectrum of diagnosed protozoan and helminth species was somewhat narrower than seen in hospital patients, but their prevalence rates were higher, except for the flagellate Pentatrichomonas hominis. The highest prevalence rates recorded were for E. histolytica 29.5% (age category 10-14 years), for G. lamblia 34.8% (age category 6-9 years), for P. hominis 19.3% (age category 3-5 years), for E. hominis 10.5% (age category 3-5 years), for A. duodenale 85.9% (age category 15-18 years), for A. lumbricoides 26.1% (age category 6-9 years), and for S. stercoralis 18.8% (age category 6-9 years). As many as 70% of children at the age between 6 and 15 years were simultaneously infected with two or three species of intestinal parasites.     

Tritrichomonas foetus and not Pentatrichomonas hominis is the etiologic agent of feline trichomonal diarrhea

Recently, several investigators have reported large-bowel diarrhea in cats associated with intestinal trichomonad parasites. These reports have presumptively identified the flagellates as Pentatrichomonas hominis, a n organism putatively capable of infecting the intestinal tracts of a number of mammalian hosts, including cats, dogs, and man. The purpose of the present study was to determine the identity of this recently recognized flagellate by means of rRNA gene sequence analysis; restriction enzyme digest mapping; and light, transmission, and scanning electron microscopy (SEM).     

Effect of the Antimicrobial Peptide Tritrpticin on the In Vitro Viability and Growth of <Emphasis Type="Italic">Trichomonas vaginalis</Emphasis>

Antimicrobial peptides are widely distributed in nature; they play important roles in several aspects of innate immunity and may provide a basis for the design of novel therapeutic agents. In this study, C-amidated tritrpticin, a 13 amino acid tryptophan-rich antimicrobial peptide derived from a porcine cathelicidin, was tested against Trichomonas vaginalis, a protozoan that causes a serious non-viral sexually transmitted disease associated with preterm birth, low birth weight, and high risk of HIV-1 infection. Tritrpticin was selected due to its reasonably easy synthesis and because analogs with lower toxicity may be designed. Our results show that tritrpticin-NH₂ at either 100 or 200 μg/ml (52.5 or 105 μM) clearly reduces the viability and growth of Trichomonas vaginalis. Together with tritrpticin-NH₂, sodium bicarbonate further limited trichomonad growth. Additionally, a low concentration of metronidazole (5.8 μM), the most commonly used medication for Trichomonas vaginalis, was more effective against the growth of the parasite when it was combined with tritrpticin-NH₂.     

Concordance between genetic relatedness and phenotypic similarities of Trichomonas vaginalis strains

Background  

Despite the medical importance of trichomoniasis, little is known about the genetic relatedness of Trichomonas vaginalis strains with similar biological characteristics. Furthermore, the distribution of endobionts such as mycoplasmas or Trichomonas vaginalis virus (TVV) in the T. vaginalis metapopulation is poorly characterised.     

Prevalence of Candida albicans and Trichomonas vaginalis in pregnant women in Havana City by an immunologic latex agglutination test

We aimed to estimate the prevalence of Candida albicans and Trichomonas vaginalis in immunocompetent pregnant women living in Havana City, Cuba, with or without symptoms of vaginitis, using a sample of 640 women from 6 Gyneco-obstetrics hospitals, which represents 2.5% of total yearly pregnant women. Diagnosis was made using a new latex agglutination kit (Newvagin C-Kure, La Habana, Cuba). Clinical sensitivity and specificity of this assay were validated against culture method, with 467 and 489 clinical specimens for Candida albicans and Trichomonas vaginalis, respectively. Results showed that the kit clinical sensitivity was 100% for Candida albicans and 86.7% for Trichomonas vaginalis compared with a clinical specificity of 93.3% for Candida albicans and 95.1% for Trichomonas vaginalis by culture. The prevalence of candidiasis was determined to be 42.3% (95% confidence interval [CI] 3.8%); the prevalence of trichomoniasis was 9.84% (95% CI 2.3%). In our sample, 48.7% of the women tested negative with respect to both candidiasis and trichomoniasis. Only 6.41% of the cases yielded inconclusive results. The test has high sensitivity, and our results indicate a relatively high prevalence of both infections. However, a significant difference (P < .001) was also observed in candidiasis and trichomoniasis prevalence among hospitals corresponding to the quantity of women with clinical vaginitis. No difference was observed between diabetics and nondiabetics, probably due to the special care of diabetic pregnant women. We conclude that the method is useful for this kind of vaginitis prevalence study and that candidiasis and trichomoniasis prevalences in pregnant women of Havana are 38.5% to 46.2 % (95% CI) and 7.5% to 12.1% (95% CI), respectively.     

Cover Picture

Trichomonas parasites present a structure called “costa”, presented here in a three dimensional reconstruction of electron tomography of the isolated costa.     

Intestinal parasites in the Camiri, Gutierrez and Boyuibe areas, Santa Cruz Department, Bolivia

A parasitological study was carried out on 381 apparently healthy subjects from Camiri, Boyuibe, Gutierrez. Intestinal parasites and non-pathogenic protozoa were present in 78.7% of the population sampled; multiple infections were observed in 67.7% of the parasitized individuals. The protozoon most commonly found was Entamoeba coli (in 40.7% of specimens), followed by Giardia intestinalis (30.7%), Iodamoeba bütschlii (10%), Chilomastix mesnili (8.7%). Other protozoon parasites also present were Enteromonas hominis (3.4%), Retortamonas intestinalis (2.4%), Cryptosporidium (2.1%), Endolimax nana (2.1%), Balantidium coli (1.8%) and Pentatrichomonas hominis (0.8%). The helminths observed were hookworms (28.6%), Trichuris trichiura (19.7%), Ascaris lumbricoides (9.7%), Hymenolepis nana (8.7%), Trichostrongylus (5.5%), Strongyloides stercoralis (1.8%), Taenia (5 cases) and Enterobius (6 cases). Prevalence for nematodes is probably underestimated in the 3-9 years age group because of a mebendazole treatment given 5 weeks before the survey, under a Program of P D C of the Ministry of Health. The sample from Camiri was found to be the most parasitized (84.1%). An extraordinarily high infection rate was found in two urban institutions, as well as in Itanambicua, a rural community close to Camiri. No significant differences were observed in parasitic prevalence between rural and urban environments. Exposure to contamination with human and animal faeces, overcrowding and poor sanitation habits are some of the factors responsible for the parasitic situation evidenced.