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PubMed2000

Improvement of silver impregnation technique (protargol) to obtain morphological features of protists ciliates, flagellates and opalinates.

The research on ciliates, flagelates and opalinates have been widespread by the utilization of techniques employing silver impregnation (protargol), modified by several authors. However, these are time consuming and its results are variable. The present work is a variant of the technique described by Tuffrau (1964, 1967) showing some adaptations made in our laboratory. The organisms can be preserved by different fixatives (alcoholic Bouin, Stieve's fluid, 2.5% glutaraldehyde and others) and then rinsed in destilled water followed by a fast clarification by 3% sodium hypochloride. If the organism is very sensitive to hypochloride, 4% sodium lauryl sulfate may be used and then washed 3 times in distilled water. The protista can be adhered to the glass slides with Mayer's glycerinated-albumin (1 glycerin vol. to 1 or 2 albumin vol.), diluted in water at a proportion of 1:10 Cv/v., or with 1% polylysine followed by fast washes with distilled water. After the slide preparation, they were covered with a layer of 0,8% Silver proteinate. Right after that, the slide has to be placed in a glass tray lined with moist tissue and covered to prevent the proteinate to dry. The tray was placed in a incubator at 40 degrees - 50 degrees C for 30 minutes. The slides are rinsed for 1 minute. with warm (35 degrees C) distilled water. The development of the material should be done with 0.4% hydroquinone with a maximum incubation time of 1 minute. It should be developed gradually, controlling the silver impregnation intensity by observation under optical microscope. Next, rinse in distilled water for 1 minute, and then, fix in 2,5% Sodium thiosulfate. Rinse the slide for two minutes before dehydrating it in an alcoholic serial 50-100 degrees. Finally rinse the slides in xylene. Mount the slides with Entellan MerckTM or Canada balsam.

Animals↗
PubMed2005

Co-infection between influenza virus and flagellated bacteria.

Trypsin is required in the hemagglutinin (HA) cleavage to in vitro influenza viruses activation. This HA cleavage is necessary for virus cell entry by receptor-mediated endocytosis. Bacteria in the respiratory tract are potential sources of proteases that could contribute to the cleavage of influenza virus in vivo. From 47 samples collected from horses, pigs, and from humans, influenza presence was confirmed in 13 and these samples demonstrated co-infection of influenza with flagellated bacteria, Stenotrophomonas maltophilia from the beginning of the experiments. Despite treatment with antibiotics, the bacteria remained resistant in several of the co-infected samples (48.39%). These bacteria, considered opportunistic invaders from environmental sources, are associated with viral infections in upper respiratory tract of hosts. The protease (elastase), secreted by Stenotrophomonas maltophilia plays a role in the potentiation of influenza virus infection. Proteolytic activity was detected by casein agar test. Positive samples from animals and humans had either a potentiated influenza infectivity or cytopathic effect (CPE) in MDCK and NCI H292 cells, Stenotrophomonas maltophilia were always present. Virus and bacteria were observed ultrastructurally. These in vitro findings show that microbial proteases could contribute to respiratory complications by host protease activity increasing inflammation or destroying endogenous cell protease inhibitors.

Animals↗
PubMed2006

[Natural infection of Triatoma vitticeps (Stal, 1859) with flagellates morphologically similar to Trypanosoma cruzi (Chagas, 1909) in Espírito Santo State].

Adult specimens of Triatoma vitticeps are frequently captured by residents in rural areas of the State of Espírito Santo, Brazil. With aim of determining the natural infection rate of this species, we examined the excrement of 116 wild specimens, captured in 27 municipal districts of the state, after blood meal in chicken and spontaneous excretion. Of these, 100 (86.2%) were infected with flagellates morphologically similar to Trypanosoma cruzi. Our results showed natural infection rates of Tritoma vitticeps superior to previous studies. The low incidence of Chagas disease in the state is probably due to late excretion in this vector, given that works of alimentary specificity demonstrated the presence of Tritoma vitticeps in intradomiciliary and frequent contact with humans. The high rate of natural infection observed reinforces the need for sustained entomologic surveillance on this triatomine.

Animals↗
PubMed2002

Species diversity and flagellate infections in the sand fly fauna near Porto Grande, State of Amapá, Brazil (Diptera: Psychodidae. Kinetoplastida: Trypanosomatidae).

Forty-six species of Lutzomyia and one species of Brumptomyia were identified among 20,008 sand flies collected in central Amapá. L. squamiventris maripaensis, L. infraspinosa, L. umbratilis, and L. ubiquitalis accounted for 66% of the specimens caught in light traps, and L. umbratilis was the commonest of the 16 species found on tree bases. Seven species of Lutzomyia including L. umbratilis were collected in a plantation of Caribbean pine. Sixty out of 511 female sand flies dissected were positive for flagellates. Among the sand flies from which Leishmania was isolated, promastigotes were observed in the salivary glands and foregut of 13 out of 21 females scored as having very heavy infections in the remainder of the gut, reinforcing the idea that salivary gland invasion may be part of the normal life cycle of Leishmania in nature. Salivary gland infections were detected in specimens of L. umbratilis, L. whitmani and L. spathotrichia. Parasites isolated from L. umbratilis, L. whitmani and also from one specimen of L. dendrophyla containing the remains of a bloodmeal, were compatible with Le. guyanensis by morphology and behaviour in hamsters.

Animals↗
PubMed1999

Flagellates and ciliates.

This article includes information on two human parasites, one protozoan flagellate, Giardia lamblia, and one ciliate, Balantidum coli. Both are transmitted through ingestion of food and water contaminated with fecal material. G. lamblia may be the most common intestinal protozoan found in humans throughout the world and causes a wide range of symptoms, all of which can be confused with other infectious and noninfectious causes. Although B. coli tends to be more restricted and associated with pigs as potential reservoir hosts, this organism can also cause mild to severe symptoms and can be found throughout the world.

Animals↗
PubMed1999

Clinical and pathological observations on natural infections of cryptosporidiosis and flagellate protozoa in leopard geckos (Eublepharis macularius).

A group of adult leopard geckos (Eublepharis macularius) which had been losing weight for several months were found to be infected with Cryptosporidium species. Histological and electron microscopical investigations on the intestines of five of the lizards revealed the presence of large numbers of the developmental stages of Cryptosporidium species attached to the mucosal surface of the lower intestine, and large numbers of flagellate protozoa, suspected to be predominantly Trichomonas species, in the gut lumen. The clinical signs were attributed to the presence of one or both types of parasites.

Animals↗
PubMed1999

[Dientamoeba fragilis: pathogenic flagellate?].

INTRODUCTION: D. fragilis is an intestinal protozoa whose pathogenic characteristics are increasingly recognized. The aim of this study is to specify the epidemiologic, biological and clinical aspects of this protozoa. MATERIAL USED AND METHODOLOGY: Survey conducted on 27,058 parasitological test of stools in parasitology-mycology laboratory of the Sfax University Hospital over a period of 5 years. RESULTS: 11,254 parasitological test of stools were positive (41.6%) of which 89.3% comprised protozoa. D. fragilis was found in 1497 cases (13.3% of the positive cases). In 65% of these cases, it was associated with other intestinal parasites in particular Blastocystis hominis (40.3%), Endolimax nanus (24%), Entamoeba coli (6%), Giardia intestinalis (5.7%) and Enterobius vermicularis (5%). Those patients having a parasitism with isolated D. fragilis were predominantly female and young subjects (< 20 years). Clinical signs included abdominal pain (88.5%), anorexia (50%), alternating diarrhoea and constipation (40.4%) and diarrhoea (21%) with mucus in 7.6%. DISCUSSION: D. fragilis is today classified in the group of flagellates and we share the opinion of the majority of the authors as to its real pathogenic capacity.

Abdominal Pain↗
PubMed1999

Dientamoeba fragilis: the unflagellated human flagellate.

Dientamoeba fragilis is a pathogenic protozoan parasite with a world-wide distribution. Although originally described as an amoeboid organism, it has been reclassified as a flagellate, on the basis of a number of electron microscopic and immunological findings. Except for its lack of a flagellum, D. fragilis closely resembles Histomonas and Trichomonas. Interestingly, a resistant cyst stage has not been demonstrated and it is unlikely that its trophozoites can survive successfully outside the human host. As a consequence of its higher than anticipated coincidence of infection with Enterobius vermicularis, transmission may occur via ova of this pinworm. D. fragilis infection may be acute or chronic, and has been reported in both children and adults. The most common clinical symptoms include abdominal pain, persistent diarrhoea, loss of appetite, weight loss and flatulence. Occasionally, eosinophilia, urticaria and pruritus have been described. Demonstration of the characteristic nuclear structure of D. fragilis, needed for a definitive diagnosis, cannot be achieved in unstained faecal material; therefore, permanently stained smears are essential. Treatment is recommended in symptomatic cases, and iodoquinol, tetracycline and metronidazole have been used successfully.

Animals↗
PubMed2001

Phototoxicity of azaarene isomers to the marine flagellate Dunaliella tertiolecta.

Many studies have shown that narcosis or baseline toxicity of polycyclic aromatic hydrocarbons (PAHs) is strongly related to their lipophilicity. For azaarenes, such relationships have also been demonstrated, but for some compounds, deviations from these relationships have been observed, even for closely related compounds such as isomers. In the present study, the toxicity of four azaarene isomer pairs to the marine flagellate Dunaliella tertiolecta was determined. For quinoline, isoquinoline, acridine, phenanthridine, benz[a]acridine, and benz[c]acridine, the 72-h median effective concentrations for growth were 571, 464, 2.10, 14.7, 0.50, and 0.11 microM, respectively. For the five-ringed isomers dibenz[a,i]acridine and dibenz[c,h]acridine, no effects were observed at the highest concentration tested (0.1 and 0.005 microM, respectively). Growth inhibition by the two-, three-, and four-ringed isomer pairs to D. tertiolecta was well described by molecular volume and log Kow, indicating a narcotic mode of action. However, the toxicity of acridine and benz[c]acridine was much higher than that of their respective isomers, phenanthridine and benz[a]acridine, suggesting an additional specific mode of action. Based on the differences in energies between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, acridine and benz[c]acridine are susceptible to ultraviolet (UV) radiation, in contrast to the other tested compounds. Because UV was present, it is therefore argued that the toxicity of both compounds was photoenhanced. Photoenhanced toxicity may increase the environmental hazard of azaarenes, indicating the importance of enlarging the present monitoring of PAHs with phototoxic N-heterocyclic PAHs and incorporating this mode of action in water-quality criteria.

Animals↗
PubMed1994

Gravitaxis in the flagellate Euglena gracilis--results from NiZeMi, clinostat and sounding rocket flights.

Many motile microorganisms including flagellates such as the green Euglena gracilis move up and down within the water column and use a number of external clues for their orientation, the most important of which may be light and gravity. The cells use positive phototaxis and negative gravitaxis to move closer to the surface of the water column which for energetic reasons is vital for their survival. However, most phytoplankton organisms cannot tolerate the bright irradiance of unfiltered solar radiation at the surface which also bleaches the photosynthetic pigments, disables the photosynthetic apparatus and impairs phototaxis, gravitaxis and motility in Euglena. Thus, it is not surprising that at higher irradiances negative phototaxis operates antagonistically to the responses described above to guide the cells into deeper water where they are protected from excessive radiation. Phototaxis and gravitaxis are not independent from one another: in a vertically positioned cuvette negative gravitaxis can be "titrated" by light impinging from above and is compensated at about 30 W m-2. While the photoreceptor for phototaxis has been identified in Euglena gracilis biochemically and spectroscopically, the gravireceptor is not yet known. Young cultures of Euglena gracilis show a positive gravitaxis, the ecological signficance of which is not yet understood while older cultures show negative gravitaxis. One hypothesis concerning the nature of graviperception is based on a passive physical process such as an asymmetric distribution of the mass within the cell. However, the observation that short term UV irradiation decreases the precision of negative gravitaxis rather indicates the involvement of an active physiological gravireceptor. Furthermore, some heavy metal ions have been found to change the direction of movement from positive to negative gravitaxis in young cells.

Animals↗
PubMed1995

Gravitaxis in the flagellate Euglena gracilis is controlled by an active gravireceptor.

Gravitactic orientation was investigated in the unicellular photosynthetic flagellate, Euglena gracilis, under different accelerations between 0 and 1.5 x g during a recent space flight on board the American shuttle Columbia. The threshold for gravitaxis was found at < or = 0.16 x g. Above the threshold the precision of orientation increased with acceleration in a sigmoidal fashion and reached saturation at about 0.32 x g, a behavior typical for physiological receptors. At accelerations above the saturation point the cells were closely aligned with the gravity vector (negative gravitaxis) and deviated more and more as the acceleration decreased. Obviously the gravireceptor responds to an error signal that elicits a course correction, again indicating the involvement of an active physiological gravireceptor. No adaptation of the cells to the conditions of weightlessness could be observed over the duration of the space mission (12 days). After landing, the cells showed a normal gravitactic behavior at 1 x g.

Acceleration↗
PubMed1990

Responses of the photosynthetic flagellate, Euglena gracilis, to microgravity.

Motility and orientation have been studied in the unicellular photosynthetic flagellate. Euglena gracilis, using real time image analysis capable of tracking up to 200 cells simultaneously before, during and after a sounding rocket (TEXUS) experiment. The cells orient negative gravitactically under 1 g conditions and the degree of orientation increases with time when kept in a closed system. Under micro-g conditions the cells orient randomly and display no cooperativity between the individuals. Under 1 g conditions the velocity, which has been determined simultaneously to the orientation vectors, depends on the direction of swimming with respect to the gravity vector. Under micro-g conditions the cells swim significantly faster. After retrieval of the rocket the cells returned to normal gravitaxis and motility as observed before the space flight.

Animals↗
PubMed1993

Phototaxis in the flagellate, Euglena gracilis, under the effect of microgravity.

Positive phototaxis was analyzed in the unicellular photosynthetic flagellate, Euglena gracilis, under the conditions of microgravity during a parabolic rocket flight (TEXUS experiment). The fluence rate at which positive phototaxis changes to negative phototaxis was the same in a sample which had previously been exposed to microgravity as in a sample which had not been exposed to microgravity. During weightlessness the precision of positive phototaxis is higher than at 1 g at the same fluence rate. The swimming velocity of the cells is higher at 0 g than at 1 g confirming previous results that under terrestrial conditions the cells are subject to simultaneous sedimentation while they swim upward. Tracks of organisms recorded at 0 g show much more frequent deviations from the straight path than those at 1 g.

Animals↗
PubMed1997

Long-term cultivation of the flagellate Euglena gracilis.

Euglena gracilis, a unicellular photosynthetic flagellate, serves as a model system in signal transduction research. To further study its complex gravitaxis, experiments under microgravity are desirable. In preparation for long-term experiments on a space station, an autonomous cultivation unit has been developed and the culture conditions and surveillance methods have been established. The running time of more than 600 d under closed conditions with light as the only source of energy confirmed the stability of the Euglena population and gave new insights into its behavior. Physicochemical parameters such as oxygen concentration, temperature and pH as well as physiological parameters including cell density, motility, gravitactic orientation and pigmentation were recorded on a frequent basis. The suitability of the botanical bioreaction to serve as an oxygen supplier for animals in a closed system was demonstrated.

Animals↗
PubMed1995

Isolation and characterization of flagellates from rodents and canids in Masinga, Machakos District, Kenya.

A total of 728 animals comprising of 633 rodents and 95 canids were examined for leishmanial parasites. Flagellates were isolated from 67 out of 111 (60.4%) Acomys subspinosus (spiny mouse), 12 out of 143 (8.4% ) Mastomys natalensis (multimammate rat), 2 out of 50 (4.0%) Lemniscomys striatus (striped mouse), 2 out of 6 (33.3%) Herpestes sanguineus (slender mongoose), 1 of 1 Helogale parvula (dwarf mongoose) and 1 out of 84 Canis familiaris (domestic dog). All isolates were characterized by Isoenzyme analysis using nine enzymes, namely, malate dehydrogenase (MDH), phosphoglucomutase (PGM), glucose phosphate isomerase (GPI), isocitrate dehydrogenase (ICD), nucleoside hydrolase (NH), glucose 6-phosphate dehydrogenase (G6PD), malic enzyme (ME), 6-phosphogluconate dehydrogenase (GPGD) and mannose phosphate isomerase (MPI). Enzyme profiles of these isolates were compared with those of five WHO Leishmania reference strains and five well characterized rodent trypanosomes of the subgenus Herpetosoma. The profiles of the isolates were found to be different from those of the Leishmania and Trypanosoma reference strains but the parasites were morphologically similar to rodent trypanosomes. These results suggest that Leishmania parasites were not among the isolates. The enzymes profiles of the three mongoose isolates were identical but differed from profiles of isolates from rodents and dog. This is the first time in Kenya that a high prevalence of nonpathogenic trypanosomes is reported in rodents and canids. From the epidemiological point of view, these trypanosomes must be differentiated from the pathogenic species of trypanosomes and Leishmania that infect man and other animals. The results of this study suggest that rodents do not seem to play a role as reservoirs of Leishmania parasites in Masinga Location, Kenya.

Journal Article↗
PubMed2002

High light exposure leads to a sign change in gravitaxis of the flagellate Euglena gracilis.

In the absence of other external stimuli the motile, unicellular freshwater flagellate Euglena gracilis normally swims upward in the water column (negative gravitaxis). This behavior is most likely triggered by active physiological orientation mechanisms. Recently it was found that negative gravitaxis often inverts to a positive one upon high light exposure. This response is not mediated by the photoreceptor (the paraxonemal body - PAB), because PAB-free mutants do also show this response after high radiation. It is very likely that the phenomenon is triggered by reactive oxygen species, because in the absence of oxygen no gravitaxis sign change was observed. Also increased salinity inverses the sign of gravitaxis, leading to the assumption that environmental stressors induce the formation of reactive oxygen species, serving as signal molecules.

Journal Article↗
PubMedDate not supplied

Simultaneous acral nodular eruption and flagellate erythema caused by bleomycin.

A 29-year-old male with AIDS was treated with bleomycin and vincristine for visceral Kaposi's sarcoma. Three days later, he developed two distinct eruptions simultaneously. One eruption was characterized by tender, erythematous, edematous plaques and nodules on the palmar and dorsal surfaces of the hands, forearms, and elbows. The other consisted of grouped, erythematous, hyperpigmented streaks on the trunk, buttocks, and extremities. The patient subsequently received a second treatment consisting of vincristine with adriamycin, without bleomycin, and no cutaneous effects were seen. Diagnoses of flagellate erythema and acral nodular eruption secondary to bleomycin were made and confirmed histopathologically. To our knowledge, this is the first report of two cutaneous side effects of bleomycin appearing simultaneously in a patient with AIDS.

Acquired Immunodeficiency Syndrome↗