| the effects of some factors on the growth and morphology of naegleria sp. and three strains of the genus acanthamoeba. | the effects of various biophysical and chemical factors on the cytology of vegetative stages of naegleria sp., vitek strain, acanthamoeba culbertsoni, acanthamoeba castellanii, neff strain and acanthamoeba polyphaga, no. 1289, were studied. the amoebae were cultured in a liquid medium under axenic conditions. the optimum temperature was 37 degrees c for pathogenic strains of naegleria sp. and acanthamoeba culbertsoni and 20 degrees c for a. castellanii. no changes were observed in the growth of ... | 1975 | 4366 |
| experimental pneumonitis and encephalitis caused by acanthamoeba in mice: pathogenesis and ultrastructural features. | for a more precise definition of the clinicopathological features of experimental acanthamoebic infection in mice, trophozoites of acanthamoeba castellanii and acanthamoeba polyphaga were instilled intranasally into adult white mice. eight to 20 days after inoculation, severe pulmonary disease developed; one to two days later, neurological signs ensued. on pathologic examination an amebic broncho-pneumonia associated with encephalitis was found. trophozoites and cysts were seen in lung and brain ... | 1975 | 48530 |
| cryptococcus neoformans: pseudohyphal forms surviving culture with acanthamoeba polyphaga. | during experiments on the gastrointestinal tract as a possible portal of entry for cryptococcus neoformans, we occasionally observed the free-living amoeba, acanthamoeba polyphaga, growing in the presence of c. neoformans cultured from mouse feces. examination of the amoebic trophozoites revealed that they were engorged with yeast cells. over a period of 2 to 3 weeks of incubation, the amoebae apparently killed most of the yeast cells. some of the surviving c. neoformans cells formed atypical co ... | 1978 | 352931 |
| quantation by flow microfluorometry of total cellular dna in acanthamoeba. | the dna content of five species of acanthamoeba was determined by flow microfluorometry. acanthamoeba castellanii (ac-30), acanthamoeba polyphaga (apg and p-23), acanthamoeba rhysodes, acanthamoeba culbertsoni (a-1), and acanthamoeba royreba were grown in a casitone based medium 24-48 hr. the trophozoites were harvested, and evaluated for dna-bound fluorescence. all species tested has dna values between 2.0-5.0 pg/cell. these results placed dna/cell values of acanthamoeba slightly lower than dna ... | 1978 | 361883 |
| cryptococcus neoformans: gastronomic delight of a soil ameba. | during 7 days of incubation in vitro the trophozoite stage of the free-living soil amoeba, acanthamoeba polyphaga, phagocytized and killed 78-97% of the cells of three strains of cryptococcus neoformans. with one strain, incubation time was increased to nine days and 99% of the yeast cells were killed. it was calculated that during 4-9 days of incubation a single trophozoite phagocytized and killed a daily average of 84 yeast cells. the lethal effect of a. polyphaga on c. neoformans may represen ... | 1979 | 394365 |
| isolation, identification, and biological characterization of acanthamoeba polyphaga from a human eye. | trophozoites and cysts of an acanthamoeba were repeatedly isolated from the corneal scrapings of a patient suffering from acute ulceration of the right eye. the ameba was cloned and cultivated axenically in a proteose peptone-yeast extract-glucose medium. at a later date the organism was identified as a. polyphaga on the basis of its morphologic characteristics, especially those of cysts. experimental studies on the in vitro interaction of this organism with monkey kidney tissue culture (vero li ... | 1975 | 811126 |
| in vitro susceptibility of pathogenic naegleria and acanthamoeba speicies to a variety of therapeutic agents. | six pathogenic strains of naegleria fowleri, two of acanthamoeba castellanii, and three of acanthamoeba polyphaga were tested in vitro for susceptibility to a variety of potentially useful therapeutic agents. minimal motility inhibitory concentrations and minimal inhibitory concentrations were determined by a technique of subculturing pure clones of amoebae in plastic tissue culture chamber slides containing liquid axenic media and serially diluted drug, incubating at 30 degrees c for acanthamoe ... | 1976 | 984777 |
| acanthamoeba polyphaga keratitis and acenthamoeba uveitis associated with fatal meningoencephalitis. | | 1975 | 1064220 |
| [an electrophoretic karyotype of acanthamoeba polyphaga]. | an electrophoretic karyotype of acanthamoeba polyphaga has been preliminarily analysed by means of pulse field gel electrophoresis (pfge). ten chromosomal dna bands are distinguishable on the gel. using yeast (saccharomyces cerevisiae) chromosomal dna as size standard, we estimate the size of the chromosomes to be between about 200 kilobase pairs (kb) and 2 megabase pairs (mb). | 1992 | 1394895 |
| effects of magainins on ameba and cyst stages of acanthamoeba polyphaga. | amebic keratitis produced by acanthamoeba spp. is an increasingly important ocular infection in extended-use contact lens wearers. problems associated with the infection are compounded by the lack of effective and well-tolerated chemotherapeutic agents. the magainins, a group of naturally occurring and synthetic membrane-active peptide compounds, have been shown to be active in vitro against a clinical isolate of acanthamoeba polyphaga. two magainins tested extensively had minimal inhibitory and ... | 1992 | 1416825 |
| relationship between legionella pneumophila and acanthamoeba polyphaga: physiological status and susceptibility to chemical inactivation. | survival studies were conducted on legionella pneumophila cells that had been grown intracellularly in acanthamoeba polyphaga and then exposed to polyhexamethylene biguanide (phmb), benzisothiazolone (bit), and 5-chloro-n-methylisothiazolone (cmit). susceptibilities were also determined for l. pneumophila grown under iron-sufficient and iron-depleted conditions. bit was relatively ineffective against cells grown under iron depletion; in contrast, iron-depleted conditions increased the susceptibi ... | 1992 | 1514790 |
| acanthamoeba polyphaga panophthalmitis. | | 1992 | 1587141 |
| association of vibrio cholerae with fresh water amoebae. | an investigation was undertaken to determine whether acanthamoeba polyphaga shi and naegleria gruberi 1518/1e could affect the survival of various strains of vibrio cholerae in laboratory microcosms. in microcosms pre-inoculated with trophozoites of amoebae, all six strains of v. cholerae tested survived and multiplied during 24 h. in control microcosms without trophozoites of amoebae, survival of the v. cholerae strains was much decreased. two strains of v. cholerae were used to determine wheth ... | 1992 | 1588578 |
| incubation of water samples containing amoebae improves detection of legionellae by the culture method. | some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. we studied the effect of incubating water samples containing amoebae on the sensitivity of culture for legionellae. samples collected during investigations of legionellosis epidemics and shown by conventional culture procedures to contain amoebae, but not legionellae, were incubated at 35 degrees c and replated. legionellae were recov ... | 1992 | 1622278 |
| new method for detachment and quantitation of acanthamoeba trophozoites in culture. | trophozoites of two acanthamoeba polyphaga strains (ryd and 435) were readily detached from plastic culture flasks or multiwell plates by 5 min exposure to a detaching fluid containing 0.005% of triton x-100 and 0.05% ammonium sulphate. this treatment also led to rounding of cells and thus permitted convenient and reproducible counting by either hemocytometer or electronic particle counter. the detaching fluid did not impair viability even after exposure up to 1 h. | 1991 | 1796243 |
| effect of contact lens preservatives on acanthamoeba. | single preservatives used in contact lens solutions were evaluated for their effectiveness in killing acanthamoeba castellanii and acanthamoeba polyphaga trophozoites and cysts. preservatives were tested against amoebae at intervals varying from 30 minutes to 24 hours. the preservatives were tested with axenically and nonaxenically grown organisms. chlorhexidine (0.001% and 0.005%), polyaminopropyl biguanide (0.0015%), benzalkonium chloride (0.001% and 0.004%), and hydrogen peroxide (3%) were ve ... | 1991 | 1866136 |
| growth of acanthamoeba on human corneal epithelial cells and keratocytes in vitro. | acanthamoebic keratitis, a potentially devastating infection usually associated with contact lens wear, has been recognized with increasing frequency in recent years. once the acanthamoeba organisms gain access to the human cornea, it is not clear which constituents of the corneal milieu provide a substrate for their growth. the growth of acanthamoeba polyphaga was investigated on cultured monolayers of human corneal epithelial cells, stromal keratocytes, and stromal homogenate suspensions. grow ... | 1991 | 1993587 |
| infection of the central nervous system due to acanthamoeba. | it is well established that acanthamoeba castellanii, acanthamoeba culbertsoni, acanthamoeba polyphaga, and probably other species of free-living amebas are virulent opportunists capable of producing disease in humans and animals. human infections involving brain, eyes, skin, and lungs have been reported from all continents. central nervous system (cns) infection due to acanthamoeba species usually occurs in chronically ill, debilitated individuals, some of them receiving immunosuppressive thera ... | 1991 | 2047674 |
| ultra-structure and localisation of formazan formed by human neutrophils and amoebae phagocytosing virulent and avirulent legionella pneumophila. | legionella pneumophila (lp) strains of differing virulence were incubated with a solution of nitroblue-tetrazolium (nbt) at a concentration of 1 mg.ml-1 in the presence of acanthamoeba polyphaga or human polymorphonuclear neutrophils (pmn). reduction of nbt to formazan occurred at a faster rate in the presence of virulent strains. reduction appeared to be temperature dependent; at 37 degrees c the reaction rate was higher than at 20 degrees c. on microscopic examination, deposits of formazan aro ... | 1990 | 2073410 |
| survival of acanthamoeba in contact lens rinse solutions. | acanthamoeba may cause a severe keratitis in contact lens wearers. since most sterilization techniques require rinsing the lenses prior to insertion, contaminated solutions represent a potential vector for transmission of acanthamoeba. the ability of rinse solutions to sustain an inoculum of acanthamoeba polyphaga was investigated. a. polyphaga was exposed to 0.1% benzalkonium chloride, 0.001% thimerosal/0.1% edetate disodium, 0.1% edetate disodium, saline, tap water, and distilled water. the st ... | 1990 | 2127739 |
| acanthamoeba keratitis and contact lens wear: the patient is at fault. | the avoidance of nonsterile solutions is important to curtailing acanthamoeba keratitis, a serious infection that has been found to occur with all types of contact lens (cl) wear. increased patient education, revised recommendations regarding the use of tap and distilled water, and improved disinfecting systems are vital to preventing infection. these precautions are particularly important since it appears that acanthamoeba, unlike pseudomonas, may not require an epithelial defect to establish c ... | 1990 | 2189677 |
| survival of legionella pneumophila within cysts of acanthamoeba polyphaga following chlorine exposure. | the association between legionella pneumophila and the free-living amoeba acanthamoeba polyphaga was studied. intracellular growth of l. pneumophila within amoebic trophozoite was confirmed by kinetic growth experiments, light and electron microscopy. cysts produced from infected trophozoites were found to protect the legionellas from at least 50 mg/l free chlorine. the ability of l. pneumophila to survive within the cysts of a. polyphaga is suggested as a possible mechanism by which the organis ... | 1990 | 2196257 |
| microbiological investigations into an outbreak of pontiac fever due to legionella micdadei associated with use of a whirlpool. | in the investigation of a large outbreak of non-pneumonic legionellosis at a leisure complex in lochgoilhead, scotland all direct cultures of environmental samples were initially negative for legionellae. legionellae readily infect appropriate protozoa under suitable conditions, and following immunofluorescence to select specimens for special study, legionella micdadei was isolated from whirlpool water via co-cultivation with acanthamoeba polyphaga. l micdadei was also isolated, along with host ... | 1990 | 2199533 |
| acanthamoeba adherence to contact lenses and removal by cleaning agents. | the quantitative adherence of a keratitis isolate of acanthamoeba polyphaga to low- and high-water content non-ionic soft contact lenses and one type of rigid gas-permeable lens was investigated. adherence of trophozoite and cyst forms of the organism was observed in vitro, and adherent amoebae counted by a plaque assay method following detachment. trophozoites adhered to all lens types with adherence being statistically significantly greater to high water content soft lenses. cyst attachment oc ... | 1990 | 2226989 |
| differentiation of naegleria fowleri from acanthamoeba species by using monoclonal antibodies and flow cytometry. | monoclonal antibodies to naegleria fowleri and acanthamoeba polyphaga were analyzed by enzyme-linked immunosorbent assay, indirect immunofluorescence microscopy, and fluorescence flow cytometry to assess specificity and cross-reactivity with axenically cultured n. fowleri and acanthamoeba spp. four monoclonal antibodies to n. fowleri were specific for n. fowleri and had no reactivity to a. polyphaga. similarly, four monoclonal antibodies to a. polyphaga did not react with n. fowleri. two of the ... | 1990 | 2229384 |
| the effect of currently available contact lens disinfection systems on acanthamoeba castellanii and acanthamoeba polyphaga. | contact lens disinfection systems were evaluated for their effectiveness in killing acanthamoeba castellanii and acanthamoeba polyphaga trophozoites and cysts. amoebae were inoculated into commercially available contact lens cleaning and soaking solutions. at intervals varying from 30 minutes to 24 hours, solutions were filtered. the filters were removed and cultured for acanthamoeba organisms. striking differences were observed in the abilities of the different disinfecting solutions to kill th ... | 1990 | 2336265 |
| experimental acanthamoeba keratitis: i. preliminary findings. | experimental acanthamoeba keratitis was induced in wistar rats by intrastromal inoculation of acanthamoeba polyphaga cysts. keratitis developed in all corneas injected and was characterised by a diffuse granular opacity. the animals were examined for 70 days and a gradual reduction of keratitis was observed. pathological sections showed liquefactive stromal necrosis and acanthamoeba localised in deep stroma persisting to 70 days. a brisk inflammatory infiltrate of neutrophils and macrophages was ... | 1990 | 2393646 |
| rapid visualization of acanthamoeba using fluorescein-conjugated lectins. | we investigated the efficacy of fluorescein-conjugated lectins (fcls) for the rapid visualization of acanthamoeba species. cultures of acanthamoeba castellani, acanthamoeba culbertsoni, and acanthamoeba polyphaga were established on nonnutrient agar plates supplemented with escherichia coli. maximal trophozoite populations were established four to five days after initial subculturing; mature cysts were routinely noted three to six days later. at various time points, trophozoites and/or cysts wer ... | 1988 | 2458096 |
| contact lens disinfection by ultraviolet light. | a 253.7-nm ultraviolet light with an intensity of 1,100 microw/cm2 was tested for its germicidal activity against contact lenses and storage solutions contaminated with various corneal pathogens. the exposure time necessary to reduce a concentration of organisms from 10(6)/ml to less than 10/ml was 30 seconds for staphylococcus aureus, 60 seconds for pseudomonas aeruginosa, and 84 seconds for candida albicans. the time necessary to sterilize a suspension of 10(4)/ml acanthamoeba polyphaga was le ... | 1989 | 2512810 |
| [acanthamoeba keratitis. epidemiologic and parasitologic study]. | the amebic keratitis with acanthamoeba are until now rare, but however increasing as their diagnosis is better, and the contact lens wearers more numerous. the authors present the clinical and parasitological features of cases they did diagnose since 1986. in the immunological sphere, the t4 lymphocytes were 20% less than the normal for the first patient, and the third one had a very low level of immunoglobulins a. in the evolution sphere, the first one did received a keratoplasty; the second on ... | 1989 | 2621311 |
| marine amoebae from waters of northwest spain, with comments on a potentially pathogenic euryhaline species. | of 17 species of free-living amoebae identified in various samples of salt water, only 1, acanthamoeba polyphaga, is known to be a potential pathogen. while no deaths occurred when laboratory animals were inoculated with a. polyphaga to test for pathogenicity, the protozoa were present in the brain, liver and lungs of some but not all of the animals. | 1989 | 2732965 |
| isolation and in vitro susceptibility of acanthamoeba from a patient with keratitis. | the acanthamoebae are facultative parasites of man, and may infect the brain, skin, bone, respiratory passages and eyes. over the past several years, acanthamoeba keratitis has become a growing problem. this is the first case isolating acanthamoeba polyphaga from a corneal biopsy of an ophthalmic patient in taiwan. direct impression smear by trichrome stain gave positive result. to provide effective clinical treatment, chemotherapeutic agents available for ophthalmic use were tested for its susc ... | 1989 | 2791723 |
| acanthamoeba keratitis: report of a case. | acanthamoeba keratitis, rarely seen in taiwan, has aroused much attention in western countries in recent years because of the increasing number of reported cases and its usually disastrous outcome. most of the reported cases were closely associated with contact lens wearing. others were related to a minor trauma or contacting contaminated water. we report a case of recalcitrant corneal ulcer following trauma, which is the first reported case of acanthamoeba polyphaga keratitis proven by a specia ... | 1989 | 2794952 |
| comparative antimicrobial efficacy of soft and rigid gas permeable contact lens solutions against acanthamoeba. | ten soft contact lens cleaners, three rigid gas permeable contact lens (rgp) disinfecting-soaking solutions, and four hydrophilic contact lens disinfecting solutions were evaluated by laboratory challenge procedures for their antimicrobial efficacy against trophozoites and cysts of acanthamoeba polyphaga and acanthamoeba castellanii. miraflow was the only cleaner that killed trophozoites and cysts on all lenses during the cleaning step. a disinfecting solution preserved with chlorhexidine and on ... | 1989 | 2805312 |
| the effects of freezing and antibiotics on the viability of acanthamoeba cysts. | the effects of cryotherapy and antibiotics (paromomycin, neomycin, or propamidine isethionate) on the viability of acanthamoeba polyphaga and acanthamoeba castellani cysts were studied in vitro. either cryotherapy or exposure to antibiotic led to a decrease in the number of viable a castellani detected; a polyphaga showed variable response to the antibiotics tested. the combination of cryotherapy and antibiotic therapy was more cysticidal than either modality alone and eliminated detectable viab ... | 1989 | 2923570 |
| elevated corneal epithelial lines in acanthamoeba keratitis. | elevated corneal epithelial lines are another clinical sign in acanthamoeba corneal infection. in this report, one patient wore extended wear soft contact lenses, and another wore daily wear soft contact lenses. both patients used distilled water and salt tablets in their lens care. histopathologic examination of these lines revealed trophozoites and cysts. in one of the patients following penetrating keratoplasty, acanthamoeba castellani and acanthamoeba polyphaga were cultured by impression cy ... | 1988 | 3046583 |
| acanthamoeba-contaminated hydrogel contact lenses. susceptibility to disinfection. | acanthamoeba keratitis has frequently been associated with contact lens use. in this study, contaminated hydrogel contact lenses of patients were subjected to disinfection by thermal hydrogen peroxide and chemical (quaternary ammonium) systems. new hydrogel contact lenses contaminated by incubation on acanthamoeba polyphaga plates were similarly subjected to the disinfection systems described above. thermal disinfection was universally effective in eradicating acanthamoeba, whereas hydrogen pero ... | 1988 | 3219865 |
| amoebae and humidifier fever. | one hundred and nineteen sera from workers at four different work sites exposed to different contaminated humidifiers were examined by the immunofluorescent antibody (ifa) technique for antibodies to the amoebae acanthamoeba polyphaga and naegleria gruberi. twenty-five of the sera were from workers with humidifier fever (hf) and six from workers with work related asthma (wra) shown to be due to the contaminated humidifiers. a positive ifa test was found to correlate precipitin reaction to humidi ... | 1987 | 3301062 |
| acanthamoeba keratitis and infectious crystalline keratopathy. | two cases of acanthamoeba keratitis and infectious crystalline keratopathy, occurring simultaneously, are presented. three and 12 months after initiating topical corticosteroid therapy in cases 1 and 2, respectively, alpha-hemolytic streptococcus viridans was cultured from each cornea. topical corticosteroid therapy was initiated for the treatment of an annular stromal opacity, presumably secondary to herpes simplex keratitis. acanthamoeba was identified in culture following penetrating keratopl ... | 1987 | 3314824 |
| microbiological and histopathological confirmation of acanthamebic keratitis. | a healthy 42 yr-old woman presented with a left keratitis which she had had for 3 months. no organisms could be grown by culture of corneal scrapings for bacteria and fungi, and the condition failed to respond to topical therapy. amebic keratitis was diagnosed following corneal biopsy and cultures which grew acanthamoeba of a species similar to, but not identical with, acanthamoeba polyphaga. medical treatment was continued for 6 mth. during this time the corneal infiltrate became less prominent ... | 1988 | 3374976 |
| successful medical treatment of a corneal ulcer due to acanthamoeba polyphaga. | a 19-year-old man, who was a soft contact lens wearer for correction of myopia, presented with right corneal ulceration. the diagnosis of acanthamoeba polyphaga infection was made by culture and serology. in-vitro sensitivity tests suggested that the organism was sensitive to neosporin (polymyxin, neomycin and gramicidin) and natamycin. topical therapy with these agents resulted in complete healing of the corneal ulcer in two months. to our knowledge, our patient is the only case of successful m ... | 1986 | 3492214 |
| the action of the systemic fungicides tridemorph and fenpropimorph on sterol biosynthesis by the soil amoeba acanthamoeba polyphaga. | tridemorph and fenpropimorph, two systemic fungicides known by their inhibitory effects on sterol biosynthesis in fungi and plants, were administered in vivo to the amoeba acanthamoeba polyphaga. the compounds did not kill the cells, but modified completely their sterol pattern. fungicide-exposed cells accumulated cyclopropylsterols indicating a partial blockage of the cyclopropane isomerase as in higher plants and delta 8-sterols indicating an inhibition of the delta 8----delta 7 isomerase as i ... | 1987 | 3569273 |
| amoebae isolated from the atmosphere of mexico city and environs. | a protozoological analysis was performed from june to august, 1982 to isolate small free-living amoebae from the atmosphere by using an air vacuum sampler and several filters. monoxenic medium (nonnutritive agar plus escherichia coli) and axenic medium (de jonckheere, 1977) were used to culture the isolates. the species isolated included naegleria sp. alexeieff emend. calkins, acanthamoeba polyphaga puschkarew, vahlkampfia jugosa page, acanthamoeba astronyxis ray and hayes, acanthamoeba castella ... | 1987 | 3803333 |
| susceptibility of acanthamoeba to soft contact lens disinfection systems. | members of the genus acanthamoeba are increasingly recognized as agents of indolent, chronic, infectious keratitis. recently, acanthamoeba corneal infection has been reported in some persons who wear soft contact lenses. in this study, three "heat" and three "cold" soft contact lens disinfection systems were tested according to the manufacturers' instructions against acanthamoeba castellanii and acanthamoeba polyphaga in separate trials, and with appropriate controls. suspensions of acanthamoeba ... | 1986 | 3957582 |
| sterol biosynthesis de nova via cycloartenol by the soil amoeba acanthamoeba polyphaga. | the soil amoeba acanthamoeba polyphaga is capable of synthesizing its sterols de novo from acetate. the major sterols are ergosterol and poriferasta-5,7,22-trienol. furthermore c28 and c29 sterols of still unknown structure with an aromatic b-ring are also synthesized by the amoeba. the first cyclic sterol precursor is cycloartenol, which is the sterol precursor in all photosynthetic phyla. no trace of lanosterol, which is the sterol precursor in animals and fungi, could be detected. these resul ... | 1985 | 4074326 |
| acanthamoeba keratitis successfully treated with penetrating keratoplasty: suggested immunogenic mechanisms of action. | a patient with a corneal ulcer caused by acanthamoeba polyphaga has been successfully treated with a penetrating keratoplasty. the pathologic specimen showed no inflammatory infiltrate surrounding the intact amoeba, whereas necrotic organisms were surrounded by an intense cellular reaction. indirect immunochemical studies showed that the trophozoite stained profusely, but the cyst form exhibited the antigenic site on the cyst wall. | 1984 | 6399233 |
| [comparative in vitro activity of chlorine and bromine on the cysts of free-living amoebae]. | a continuous flow type apparatus is used for investigation of the chlorine and bromide activity in vitro on the cysts of two free-living amoeba strains : naegleria gruberi and acanthamoeba polyphaga. the naegleria cysts are sensitive more to chlorine than to bromine ; those of acanthamoeba are perfectly resistant to these disinfectants in the limit of the available concentrations in swimming-pools. the sensibility to these disinfectants stays the same at 25 degrees c and 35 degrees c. | 1980 | 6448673 |
| survey of fresh vegetables for nematodes, amoebae, and salmonella. | contamination by nematodes, amoebae, and bacteria of the genus salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. the vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. nematode eggs and larvae were recovered by the nacconol-ether centrifugation method. some nematode eggs were identified as parasitic ascaris sp.; the majority of larval nematodes were thought to be ... | 1984 | 6540260 |
| defined minimal growth medium for acanthamoeba polyphaga. | nutritional requirements of acanthamoeba polyphaga (strain pd) were compared to those reported for a. castellanii. although a. polyphaga and a. castellanii have essentially the same minimal amino acid requirements--arginine, methionine, leucine, isoleucine, and valine--a. polyphaga cannot utilize acetate as sole carbon source, but a. castellanii can if the medium is supplemented with glycine. | 1983 | 6644631 |
| phenothiazine compounds inhibit in vitro growth of pathogenic free-living amoebae. | the phenothiazine compounds trifluoperazine dihydrochloride and chlorpromazine hydrochloride have in vitro activity against the pathogenic free-living amoebae naegleria fowleri, acanthamoeba culbertsoni, and acanthamoeba polyphaga. drug concentrations of 10 microm were amoebastatic; concentrations of 50 microm were either amoebastatic or amoebicidal. concentrations of 100 microm were generally amoebicidal. the mechanism of drug action is unclear. it may reflect sensitivity of amoeba calcium regu ... | 1984 | 6703673 |
| in vitro assessment of susceptibility of acanthamoeba polyphaga to drugs using combined methods of dye-binding assay and uptake of radiolabelled adenosine. | a technique based on binding of eosin dye to cell was applied to quantitate acanthamoeba trophozoites in culture. using this technique in combination with the uptake of radiolabelled adenosine, we assessed the activities of triazole (saperconazole), imidazole (ketoconazole, miconazole) and diamidine (berenil, pentamidine, dibromopropamidine) compounds against a. polyphaga trophozoites. the quantity of dye bound to the trophozoites correlated (r = 0.99) with the number of organisms per well. when ... | 1994 | 7533747 |
| polyamine content of acanthamoeba polyphaga at different stages of development and the effect of pentamidine. | | 1994 | 7660957 |
| the effect of acanthamoeba concentration on adherence to four types of unworn soft contact lenses. | contact lens wear is a predominant risk factor for acanthamoeba keratitis. the exact nature of the relationship between organism concentration and contact lens adherence is poorly understood. we investigated the effect of acanthamoeba inoculation concentration on adherence to four categories of contact lenses of varying polymers and water content. acanthamoeba polyphaga was harvested in log growth phase at 5 days subculture and suspended in pbs at concentrations of 1 x 10(2), 10(3), 10(4), 10(5) ... | 1995 | 7712602 |
| amoebicidal efficiencies of various diamidines against two strains of acanthamoeba polyphaga. | the first medical cure of acanthamoeba keratitis was obtained by use of propamidine isethionate. since then, it has been the basic drug recommended for use in treatment. because some acanthamoeba strains have been reported to be resistant to propamidine and propamidine was found to be only weakly cysticidal, superior homologs such as butamidine, pentamidine, hexamidine, heptamidine, octamidine, and nonamidine were tested for their amoebicidal effects on two acanthamoeba strains isolated from pat ... | 1995 | 7726493 |
| antiprotozoal activities of benzimidazoles and correlations with beta-tubulin sequence. | benzimidazoles have been widely used since the 1960s as anthelmintic agents in veterinary and human medicine and as antifungal agents in agriculture. more recently, selected benzimidazole derivatives were shown to be active in vitro against two protozoan parasites, trichomonas vaginalis and giardia lamblia, and clinical studies with aids patients have suggested that microsporidia are susceptible as well. here, we first present in vitro susceptibility data for t. vaginalis and g. lamblia using an ... | 1994 | 7811023 |
| [amebic keratitis-keratitis acanthamoeba]. | in seventeen patients who suffered of corneal ulcer, and were negative in bacteriological and mycological examinations, parasitological tests were performed between 1990-1992. acanthamoeba keratitis was diagnosed in one patient with characteristic corneal changes of right eye following trauma. the patient was not a contact lens wearer. the amoeba found in direct smears of scraping from corneal ulcer and isolated and cloned in in vitro conditions (isolate-clone-no. 2961) belonged to acanthamoeba ... | 1994 | 7990337 |
| non-radioactive dna probe and polymerase chain reaction procedures for the specific detection of acanthamoeba. | acanthamoebae are potential pathogens which can cause serious infections of humans. a non-radioactive rdna probe and polymerase chain reaction (pcr) amplification procedures which are specific, rapid, sensitive and safe for the detection of acanthamoeba have been developed. a restriction fragment (126 bp; ardna-a) from a variable region of the cloned 26s rdna unit of acanthamoeba castellanii (from plasmid par2) was labelled by biotinylation. cells and dnas were incubated with the labelled rdna p ... | 1994 | 8028612 |
| calcium enhances acanthamoeba polyphaga binding to extracellular matrix proteins. | to characterize better the ameba-host interactions that may be involved with the pathogenesis of acanthamoeba keratitis, the role of calcium (ca2+) on the binding of acanthamoeba polyphaga to extracellular matrix proteins was examined in vitro. | 1994 | 8163332 |
| partial characterization of the proteolytic secretions of acanthamoeba polyphaga. | the ocular pathology associated with acanthamoebiasis may result, at least in part, from the excretory and secretory (e&s) products of the active acanthamoeba trophozoites. to test this hypothesis, the ability of a. polyphaga (atcc strain 30461) trophozoite e&s products to digest collagen, the major constituent of the corneal stroma, was evaluated. the secreted proteinases of a. polyphaga were identified using in vitro azocoll degradation, activity-page, radiolabeled extracellular matrix (ecm) d ... | 1994 | 8206136 |
| influence of intra-amoebic and other growth conditions on the surface properties of legionella pneumophila. | the surface properties of legionella pneumophila were examined by analyzing outer membrane (om) proteins, lipopolysaccharides (lps), and cellular fatty acids after growth within acanthamoeba polyphaga and in vitro under various nutrient-depleted conditions. intra-amoeba-grown legionellae were found to differ in several respects from cells grown in vitro; most notably, they contained a 15-kda om protein and a monounsaturated straight-chain fatty acid (18:1(9)). these compounds were also found in ... | 1993 | 8335382 |
| inhibition of acanthamoeba species by pseudomonas aeruginosa: rationale for their selective exclusion in corneal ulcers and contact lens care systems. | cocultivation of acanthamoeba castellanii and acanthamoeba polyphaga with live pseudomonas aeruginosa and with broth filtrates of p. aeruginosa proved equally lethal to the acanthamoeba spp. the p. aeruginosa-induced amebicidal activity is apparently toxin mediated and has two operative modes: it can function through binding of p. aeruginosa to the ameba membrane and in the presence of one or more p. aeruginosa exoproducts. | 1993 | 8349772 |
| a ribosomal protein in acanthamoeba polyphaga is conserved in eukaryotic nuclei, organelles and bacteria. | an ecori fragment from the mitochondrial dna of acanthamoeba polyphaga was cloned and partly sequenced, and the conceptual translation product of the open reading frame (partial sequence) was found to have similarities with rp114, a ribosomal protein. phylogenetic analysis based on the amino acid (aa) sequences of this conserved protein resolved four branches that consisted of: (1) eubacteria and the chloroplasts of algae and higher plants, (2) ciliate mitochondria, (3) acanthamoeba, and (4) arc ... | 1993 | 8370534 |
| comparative effects of selected azole compounds on trophic and cystic stages of acanthamoeba polyphaga. | | 1993 | 8401469 |
| acanthamoeba binds to extracellular matrix proteins in vitro. | to identify host-tissue amoeba interactions that may be important in the pathogenesis of acanthamoeba keratitis, the ability of the opportunistic pathogen acanthamoeba polyphaga to bind various components of the extracellular matrix (collagen type iv, laminin, or fibronectin) was examined in vitro. | 1993 | 8449684 |
| de novo purine biosynthesis in a free living protozoan parasite, acanthamoeba polyphaga [correction of polypha]. | a free living protozoon, acanthamoeba polyphaga 435/89, was shown to utilize radiolabelled formate and glycine as precursors for purine biosynthesis and to grow in medium devoid of any source of preformed purine compounds. the organism also incorporated into its nucleic acids radiolabel derived from adenosine and guanosine indicating presence of purine salvage pathway. thus, the presence in a. polyphaga 435/89 of active de novo purine biosynthesis in addition to a purine salvage pathway may be a ... | 1993 | 8516627 |
| acanthamoeba pearcei n. sp. (protozoa: amoebida) from sewage contaminated sediments. | seabottom sediments from a discontinued philadelphia-camden 40-mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. barge delivered wastes were discharged at the site from 1973 until 1980 when the site was closed. one station at the southeast margin of the site was sampled at a depth of approximately 50 m, twice in 1978 and once in 1982, 1983 and 1984. sediment from the 1978 collection yielded acanthamoeba polyphaga, vahlkampfia sp., and an unknown amoeba with stel ... | 1995 | 8520585 |
| adherence of cysts and trophozoites of acanthamoeba to unworn rigid gas permeable and soft contact lenses. | contact lens related acanthamoeba keratitis has been more often associated with the use of soft contact lenses than with the use of rigid gas permeable (rgp) contact lenses. we studied the adherence of acanthamoeba cysts and trophozoites to unworn rgp (silicone acrylate and fluoropolymer) and low and high water content soft contact lenses marketed in india. a human corneal isolate of acanthamoeba polyphaga suspended in saline (1 x 10(5) amoebae/ml) was used. lens segments were exposed to a. poly ... | 1995 | 8565194 |
| bacteriolytic activities of the free-living soil amoebae, acanthamoeba castellanii, acanthamoeba polyphaga and hartmannella vermiformis. | bacteriolytic activities of axenically grown free-living soil amoebae acanthamoeba castellanii, acanthamoeba polyphaga and hartmannella vermiformis towards various gram-positive and gram-negative bacteria were determined. a spectrophotometric assay revealed that the specific bacteriolytic activities of both acanthamoeba species were higher as those of the three hartmannella strains. bacillus megaterium, bacillus subtilis, chromatium vinosum, micrococcus luteus and pseudomonas fluorescens were mo ... | 1995 | 8572682 |
| interstrain polymorphisms of isoenzyme profiles and mitochondrial dna fingerprints among seven strains assigned to acanthamoeba polyphaga. | interstrain polymorphisms of isoenzyme profiles and mitochondrial (mt) dna fingerprints were observed among seven strains of acanthamoeba isolated from different sources and morphologically assigned to a. polyphaga. mt dna fingerprints by eight restriction endonucleases (bgl ii, sca i, cla i, ecor i, xba i, kpn i, sal i, and sst i) revealed considerable interstrain polymorphisms. isoenzyme profiles revealed considerable interstrain polymorphisms for acid phosphatase, lactate dehydrogenase, and g ... | 1995 | 8591011 |
| intraphagocytic growth induces an antibiotic-resistant phenotype of legionella pneumophila. | the antimicrobial susceptibilities of legionella pneumophila isolates grown either in u937 human monocytic cells or in acanthamoeba polyphaga were studied after release from the host cells without further subculture. time-survival studies showed that exposure of l. pneumophila cells, gown exclusively in vitro, to 5 micrograms of rifampin per ml resulted in at least 99% killing after 6 h and no detectable survivors at 24 h. similar rates of killing were observed for in vitro-grown cells tested by ... | 1995 | 8593002 |
| in vitro destruction of nerve cell cultures by acanthamoeba spp.: a transmission and scanning electron microscopy study. | trophozoites of 4 species of acanthamoeba were cytopathic for cultured rat b103 neuroblastoma cells. cytopathogenicity was evaluated by a chromium release assay and by transmission and scanning electron microscopy. acanthamoeba culbertsoni, acanthamoeba castellanii, and acanthamoeba polyphaga destroyed b103 target cells at 37 c as evidenced by the release of radiolabel. acanthamoeba astronyxis did not produce cytopathology at 37 c but destroyed nerve cells at 25 c. transmission and scanning elec ... | 1996 | 8885887 |
| the effectiveness of soft contact lens disinfection systems against acanthamoeba on the lens surface. | this investigation compared the efficacy of three widely used contact lens disinfection systems against an ocular isolate of acanthamoeba polyphaga. | 1996 | 8888822 |
| subgenus systematics of acanthamoeba: four nuclear 18s rdna sequence types. | classification of acanthamoeba at the subgenus level has been problematic, but increasing reports of acanthamoeba as an opportunistic human pathogen have generated an interest in finding a more consistent basis for classification. thus, we are developing a classification scheme based on rna gene sequences. this first report is based on analysis of complete sequences of nuclear small ribosomal subunit rna genes (rns) from 18 strains. sequence variation was localized in 12 highly variable regions. ... | 1996 | 8976608 |
| stable transfection of acanthamoeba. | the promoter activity of an acanthamoeba polyubiquitin gene was analyzed in its homologous system. a modified calcium phosphate transfection method using a neomycin marker vector was developed to achieve highly efficient transfection of the acanthamoeba polyubiquitin gene into acanthamoeba cells. in this transfection procedure, the calcium phosphate-dna complex was formed gradually in the medium during incubation with cells and precipitated on the cells. the crucial factors for obtaining efficie ... | 1997 | 9090113 |
| differences in isoenzyme patterns of axenically and monoxenically grown acanthamoeba and hartmannella. | axenically and monoxenically grown acanthamoeba castellanii, acanthamoeba polyphaga and different isolates of hartmannella vermiformis strains were examined by polyacrylamide isoelectric focusing in the ph range 3-10. isoenzyme patterns of acid phosphatase (ap), propionyl esterase (pe), malate dehydrogenase (mdh), alcohol dehydrogenase (adh), glucose phosphate isomerase (gpi) and phosphoglucomutase (pgm) were compared. zymograms were used to reveal differences in typical isoenzyme patterns betwe ... | 1997 | 9111916 |
| utilization of similar mechanisms by legionella pneumophila to parasitize two evolutionarily distant host cells, mammalian macrophages and protozoa. | the legionnaires' disease bacterium, legionella pneumophila, is an intracellular pathogen of humans that is amplified in the environment by intracellular multiplication within protozoa. within both evolutionarily distant hosts, the bacterium multiplies in a rough endoplasmic reticulum-surrounded phagosome that is retarded from maturation through the endosomal-lysosomal degradation pathway. to gain an understanding of the mechanisms utilized by l. pneumophila to invade and replicate within two ev ... | 1997 | 9353059 |
| heterogeneity in the attachment and uptake mechanisms of the legionnaires' disease bacterium, legionella pneumophila, by protozoan hosts. | invasion and intracellular replication of legionella pneumophila within protozoa in the environment plays a major role in the transmission of legionnaires' disease. intracellular replication of l. pneumophila within protozoa occurs in a rough endoplasmic reticulum (rer)-surrounded phagosome (y. abu kwaik, appl. environ. microbiol. 62:2022-2028, 1996). since the subsequent fate of many intracellular pathogens is determined by the route of entry, we compared the mechanisms of attachment and subseq ... | 1998 | 9435069 |
| identification of macrophage-specific infectivity loci (mil) of legionella pneumophila that are not required for infectivity of protozoa. | we have recently shown that many mutants of legionella pneumophila exhibit similar defective phenotypes within both u937 human-derived macrophages and the protozoan host acanthamoeba (l.-y. gao, o. s. harb, and y. abu kwaik, infect. immun. 65:4738-4746, 1997). these observations have suggested that many of the mechanisms utilized by l. pneumophila to parasitize mammalian and protozoan cells are similar, but our data have not excluded the possibility that there are unique mechanisms utilized by l ... | 1998 | 9488371 |
| expression of multiple pili by legionella pneumophila: identification and characterization of a type iv pilin gene and its role in adherence to mammalian and protozoan cells. | legionella pneumophila expresses pili of variable lengths, either long (0.8 to 1.5 microm) or short (0.1 to 0.6 microm), that can be observed by transmission electron microscopy. we have identified a gene in l. pneumophila with homology to the type iv pilin genes (pilel). an insertion mutation was constructed in pilel and introduced into the l. pneumophila wild-type strain by allelic exchange. the pilin mutant is defective for expression of long pili. reintroduction of the pilin locus on a cosmi ... | 1998 | 9529112 |
| isolation of an amoeba naturally harboring a distinctive legionella species. | there are numerous in vitro studies documenting the multiplication of legionella species in free-living amoebae and other protozoa. it is believed that protozoa serve as host cells for the intracellular replication of certain legionella species in a variety of environmental settings. this study describes the isolation and characterization of a bacterium initially observed within an amoeba taken from a soil sample. in the laboratory, the bacterium multiplied within and was highly pathogenic for a ... | 1998 | 9572937 |
| mycobacterium avium bacilli grow saprozoically in coculture with acanthamoeba polyphaga and survive within cyst walls. | protozoans are gaining recognition as environmental hosts for a variety of waterborne pathogens. we compared the growth of mycobacterium avium, a human pathogen associated with domestic water supplies, in coculture with the free-living amoeba acanthamoeba polyphaga with the growth of m. avium when it was separated from amoebae by a 0.1-micron-pore-size polycarbonate membrane (in a parachamber). although viable mycobacteria were observed within amoebal vacuoles, there was no significant differenc ... | 1998 | 9603844 |
| the interaction of acanthamoeba spp. with activated macrophages and with macrophage cell lines. | acanthamoeba spp. are free-living amebae associated with amebic keratitis and chronic granulomatous amebic encephalitis. the present studies were undertaken to compare the pathogenicity of three species of acanthamoeba in b6c3f1 mice after intranasal challenge with acanthamoeba-induced cytopathogenicity for different macrophage populations. the ability of murine macrophage cell lines and activated murine peritoneal macrophages to lyse acanthamoeba has been assessed by coincubating macrophages wi ... | 1998 | 9703682 |
| survival of escherichia coli o157 in a soil protozoan: implications for disease. | intra-protozoal growth of bacterial pathogens has been associated with increased environmental survival, virulence and resistance to biocides and antibiotics. using laboratory microcosms we have shown that escherichia coli o157 survives and replicates in a common environmental protozoan, acanthamoeba polyphaga. as protozoa are widely distributed in soils and effluents, they may constitute an important environmental reservoir for transmission of e. coli o157 and other pathogens. | 1999 | 10227158 |
| enhanced growth of surface-attached acanthamoeba polyphaga. | | 1999 | 10610375 |
| isoenzyme patterns and phylogenetic relationships in acanthamoeba spp. isolated from contact lens containers in korea. | in order to refer to the basic information regarding the identification of isolates obtained from a contact lens container in korea, the isoelectric focusing gel electrophoresis was employed to compare the isoenzyme band patterns among acanthamoeba spp. including eight isolates and the simple pairwise dissimilarity analysis was carried out. for an alkaline phosphate development, isolate 7 and acanthamoeba polyphaga showed homologous band patterns, and isolates 1, 2, and 3 showed the same pattern ... | 1999 | 10634038 |
| unusual case of acanthamoeba polyphaga and pseudomonas aeruginosa keratitis in a contact lens wearer from gauteng, south africa. | acanthamoeba species can cause a chronic, progressive ulcerative keratitis of the eye which is not responsive to the usual antimicrobial therapy and is frequently mistaken for stromal herpes keratitis. an unusual case of coinfection with acanthamoeba polyphaga and pseudomonas aeruginosa as causes of corneal keratitis in a contact lens wearer from gauteng, south africa, is reported. these two pathogens have previously been assumed to be selectively exclusive. cysts of the isolated acanthameba tol ... | 2000 | 10655392 |
| flow cytometry for determination of the efficacy of contact lens disinfecting solutions against acanthamoeba spp. | flow cytometric analyses of cellular staining with fluorescent viability dyes and direct microscopic observations of methylene blue exclusion were compared for evaluation of the effects of a chlorhexidine gluconate-based contact lens disinfectant solution and a polyhexamethylene biguanide solution against cysts and trophozoites of acanthamoeba castellanii and acanthamoeba polyphaga. the flow cytometric procedure with propidium iodide (used to stain dead cells) indicated that more than 90% of tro ... | 2000 | 10698771 |
| survival and growth of burkholderia cepacia within the free-living amoeba acanthamoeba polyphaga. | the aim of this study was to investigate whether burkholderia cepacia is capable of survival and growth within the free-living amoeba acanthamoeba polyphaga using a differential immunofluorescence assay of bacterial-amoebal cocultures and viable counts of bacteria determined after amoebal lysis. the numbers of intra-amoebal bacteria and the numbers of infected amoebae increased over time; although, when heat-killed bacteria were used, no intracellular bacteria were observed. these findings shoul ... | 2000 | 10746499 |
| proteinase activities in total extracts and in medium conditioned by acanthamoeba polyphaga trophozoites. | acanthamoeba species can cause granulomatous encephalitis and keratitis in man. the mechanisms that underlie tissue damage and invasion by the amoebae are poorly understood, but involvement of as yet uncharacterized proteinases has been suggested. here, we employed gelatin-containing gels and azocasein assays to examine proteinase activities in cell lysates and in medium conditioned by acanthamoeba polyphaga trophozoites. azocasein hydrolysis by cell lysates was optimally detected at ph 4.0-5.0 ... | 2000 | 10780536 |
| 'candidatus odyssella thessalonicensis' gen. nov., sp. nov., an obligate intracellular parasite of acanthamoeba species. | an intracellular bacterium, strain l13, was observed infecting an environmental isolate of an acanthamoeba species. the bacterium could not be recovered on axenic medium but was recovered and cultivated in vitro using cultures of acanthamoeba polyphaga. the 16s rrna gene sequence of l13 was found to be new, sharing less than 84% similarity with other sequences in the genbank/embl database. l13 was found to be a member of the alpha-proteobacteria, sharing an evolutionary line of descent with a gr ... | 2000 | 10826788 |
| influence of sequential cultivation on virulence of legionella pneumophila and staphylococcus aureus. | virulence of legionella pneumophila strain monza 3 and staphylococcus aureus strain smith diffuse was investigated after sequential cultures on nutrient media. l. pneumophila lost its ability to multiply within acanthamoeba polyphaga after 50 passages on legionella selective agar, while s. aureus maintained its pathogenicity in the mouse peritonitis model after 100 sequential cultures on tryptic soy agar. these results demonstrate high preservation of virulence in staphylococci in contrast to le ... | 2000 | 11109570 |
| isolation of legionella anisa using an amoebic coculture procedure. | conventional diagnostic tests for legionellosis were negative for a 61-year-old immunocompromised man with pneumonia. however, coculture of a sputum sample with acanthamoeba polyphaga amoebae led to the recovery of legionella anisa. this procedure may be a sensitive and convenient diagnostic method, especially for non-legionella pneumophila species infections that can be diagnosed only by culture. | 2001 | 11136802 |
| novel bacterial endosymbionts of acanthamoeba spp. related to the paramecium caudatum symbiont caedibacter caryophilus. | acanthamoebae are increasingly being recognized as hosts for obligate bacterial endosymbionts, most of which are presently uncharacterized. in this study, the phylogeny of three gram-negative, rod-shaped endosymbionts and their acanthamoeba host cells was analysed by the rrna approach. comparative analyses of 16s rdna sequences retrieved from amoebic cell lysates revealed that the endosymbionts of acanthamoeba polyphaga hn-3, acanthamoeba sp. uwc9 and acanthamoeba sp. uwe39 are related to the pa ... | 1999 | 11207753 |
| the mechanism of killing and exiting the protozoan host acanthamoeba polyphaga by legionella pneumophila. | the ability of legionella pneumophila to cause legionnaires' disease is dependent on its capacity to replicate within cells in the alveolar spaces. the bacteria kill mammalian cells in two phases: induction of apoptosis during the early stages of infection, followed by an independent and rapid necrosis during later stages of the infection, mediated by a pore-forming activity. in the environment, l. pneumophila is a parasite of protozoa. the molecular mechanisms by which l. pneumophila kills the ... | 2000 | 11243265 |
| htra homologue of legionella pneumophila: an indispensable element for intracellular infection of mammalian but not protozoan cells. | legionella pneumophila replicates within alveolar macrophages, and possibly, alveolar epithelial cells and also within protozoa in the aquatic environment. here we characterize an l. pneumophila mutant defective in the htra/degp stress-induced protease/chaperone homologue and show that htra is indispensable for intracellular replication within mammalian macrophages and alveolar epithelial cells and for intrapulmonary replication in a/j mice. importantly, amino acid substitutions of two conserved ... | 2001 | 11254621 |
| comparison of hydrogen peroxide contact lens disinfection systems and solutions against acanthamoeba polyphaga. | acanthamoeba is a free-living amoeba causing a potentially blinding infection of the cornea. contact lens wearers are most at risk and account for some 95% of cases. hydrogen peroxide is used for contact lens disinfection due to its broad antimicrobial activity. lenses must be neutralized before use to avoid pronounced stinging and possible corneal damage. neutralization is achieved by adding a catalyst during the disinfection process (one-step) or afterwards (two-step). here, the activities of ... | 2001 | 11408220 |
| acanthamoeba polyphaga in rheumatoid arthritis: possibility for a chronic infection. | acanthamoeba polyphaga (ap) is ubiquitous in nature and frequently infects humans. ap has some features, such as persistence, which makes it an attractive candidate in studies of a possible infectious aetiology in rheumatoid arthritis (ra). in this study the occurrence of ap-specific antibodies was compared between ra patients and matched controls. | 2001 | 11422910 |
| standardized method of measuring acanthamoeba antibodies in sera from healthy human subjects. | acanthamoeba species can cause serious, debilitating, and sometimes life-threatening infections. three groups have been identified using morphological and immunological comparisons. previous serological studies have utilized a variety of antigen preparations and assay methods and reported disparate (3 to 100%) results. this study was designed to (i) optimize an enzyme-linked immunosorbent assay for detecting serum antibodies to each of the acanthamoeba serogroups and (ii) test 55 healthy individ ... | 2001 | 11427418 |
| infection of acanthamoeba polyphaga with simkania negevensis and s. negevensis survival within amoebal cysts. | simkania negevensis, a novel microorganism belonging to the family simkaniaceae in the order chlamydiales, has an intracellular developmental cycle during which two morphological entities, elementary bodies (eb) and reticulate bodies (rb), are seen by electron microscopy. rates of seropositivity to the organism are high in certain population groups, and s. negevensis has been associated with respiratory illness in humans. this study reports for the first time the ability of s. negevensis to surv ... | 2001 | 11571186 |
| t-cell responses to viral, bacterial and protozoan antigens in rheumatoid inflammation. selective migration of t cells to synovial tissue. | to identify any preferential or selective migration of t-cell specificities to inflamed tissues of rheumatoid arthritis (ra) patients. | 2001 | 11600741 |