BACKGROUND: This study aimed to evaluate the adhesion of Acanthamoeba trophozoites on cosmetic contact lenses (CLs) with and without CL care multipurpose solution (MPS) treatment. METHODS: Acanthamoeba lugdunensis L3a trophozoites were inoculated onto disks trimmed from CLs: 1-day Acuvue moist, 1-day Acuvue define, Acuvue 2, and Acuvue 2 define. After 18-hour inoculation, the number of adherent trophozoites was counted under phase contrast microscopy. The effects of MPS, Opti-Free Express, soaking CLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface. RESULTS: Acanthamoeba trophozoites showed greater adhesion to cosmetic CL (P = 0.017 for 1-day CL and P = 0.009 for 2-week CL) although there was no significant difference between the types of cosmetic CL. On all lenses, the number of adherent Acanthamoeba was significantly reduced after treatment with MPS (P < 0.001 for 1-day Acuvue moist, P = 0.046 for 1-day Acuvue define, P < 0.001 for Acuvue 2, and P = 0.015 for Acuvue 2 define), but there was still significant difference between conventional and cosmetic CLs (P = 0.003 for 1-day CL and P < 0.001 for 2-week CL, respectively). More attachment of Acanthamoeba was observed on colored area and the acanthopodia of Acanthamoeba was placed on the rough surface of colored area. CONCLUSION: Acanthamoeba showed a greater affinity for cosmetic CL and mostly attached on colored area. Although MPS that contained myristamidopropyl dimethylamine reduced the adhesion rate, there was a significant difference between conventional and cosmetic CLs.
Acanthamoeba ; Contact Lenses ; Microscopy, Phase-Contrast ; Trophozoites

Exflagellation of the malaria parasite microgametocyte usually occurs in the gut cavity of Anopheles mosquitoes following an infective blood meal. Exflagellation is a very rare event in human blood. Due to its rarity, the appearance of this structure in a peripheral blood smear will easily create a diagnostic dilemma. We report a case of malaria with exflagellated microgametes in human blood that was initially mistaken for a double infection of Plasmodium and another blood flagellate. The patient was a 29-year-old Parkistani man presenting with fluctuating fever accompanied by chills and fatigue for 4 days. Initial peripheral blood smear examination showed a number of Plasmodium ring forms, trophozoites, and gametocytes. Additionally, several filamentous structures resembling blood flagellates were seen. With these features, an initial diagnostic impression of combined infection of malaria and blood flagellate was made. Later, we determined that these structures resembling blood flagellates were exflagellated microgametes of malarial parasite. Therefore, the knowledge that exflagellation may appear in human blood with Plasmodium species infection and being more familiar with differentiation of the morphologic features of other species infection can prevent further possible misinterpretation.
Anopheles ; Chills ; Culicidae ; Fatigue ; Fever ; Humans ; Malaria ; Meals ; Parasites ; Plasmodium ; Trophozoites

Acanthamoeba keratitis has been increasing in recent years. Main risk factors are contact lens wear and their cleaning solutions. Most contact lens wearers use multipurpose disinfecting solutions (MPDS) for cleansing and disinfecting microorganisms because of its convenience. We determined amoebicidal effects of MPDS made in Korea and their cytotoxicity on human corneal epithelium cells. Fifteen commercial MPDS (A to O) were tested for their amoebicidal effects on Acanthamoeba castellanii trophozoites and cysts by using a most probable number (MPN) technique. Among them, 7 kinds of MPDS showed little or no amoebicidal effects for 24 hr exposure. Solutions A, B, G, H, L, and O showed positive amoebicidal effects, and solutions M and N killed almost all trophozoites and cysts after 24 hr exposure. However, 50%-N solution showed 56% cytotoxicity on human corneal epithelial cells within 4 hr exposure, and 50%-O solution also showed 62% cytotoxicity on human cells within 4 hr exposure. Solution A did not show any cytotoxicity on human cells. These results revealed that most MPDS made in Korea were ineffective to kill Acanthamoeba. The solutions having amoebicidal activity also showed high levels of cytotoxicity on human corneal epithelial cells. New formulations for improved MPDS that are amoebicidal but safe for host cells are needed to prevent Acanthamoeba keratitis.
Acanthamoeba castellanii* ; Acanthamoeba Keratitis ; Acanthamoeba* ; Epithelial Cells ; Epithelium, Corneal ; Humans ; Korea ; Risk Factors ; Trophozoites

BACKGROUND: In Korea, reemerging of indigenous malaria (Plasmodium vivax) have been reported in 1993 and malarial patients were rapidly increased in number and made some social problems. For the effective control for malaria cost effective, high sensitive and specific diagnostic methods has been needed. We tried to purify trophozoites of P. vivax by Percoll density gradient for detecting malaria in P. vivax infection patients who were early stage or the state after taking anti-malarial medicines. METHODS: Ten mL of EDTA venous bloods from malarial patients were collected and removed plasma after centrifugation. The packed cells were suspended by RPMI 1640 supplemented with 1% fetal bovine serum (1% FBS/RPMI) and overlaid onto the 47%, 45%, and 43% of Percoll solutions, respectively. The buffy coat and under layer were collected after centrifugation. Finally cell pellet suspension with 1% FBS/RPMI were prepared and cytospin slides were made and Wright-Giemsa stained. RESULTS: The density gradient of 43% Percoll solution showed best result for purifying P. vivax under microscopic observation. Also infected RBC with malarial trophozoite phagocytosed by activated monocyte and neutrophil were noted in 47%, 45%, and 43% of Percoll solutions. CONCLUSTIONS: The Percoll density gradient is very useful laboratory method to detect malaria in P. vivax infection patients who were early stage or the state after taking anti-malarial medicines.
Centrifugation ; Edetic Acid ; Humans ; Korea ; Malaria ; Monocytes ; Neutrophils ; Plasma ; Plasmodium vivax* ; Plasmodium* ; Social Problems ; Trophozoites

We experienced a case of chronic keratitis with corneal ulcer and conjunctival injection while wearing contact lens. In spite of broad-spectrum antibiotics therapy, corneal lesion was not improved, and bacterial smear and culture were negative. Specimens from corneal scraping were examined with Giemsa-Wright stain and H and E(Hematoxylin-Eosin) stain. We could find double walled acanthamoebic cysts. The specimens were cultured on 1.5% non-nutrient agar with E, coli suspension, and aeanthamoebic cysts and trophozoites were found with H and E stain. Aeanthamoebic cysts and trophozoites were cultured from the specimens of ulcered cornea. So we report this case.
Acanthamoeba Keratitis* ; Acanthamoeba* ; Agar ; Anti-Bacterial Agents ; Cornea ; Corneal Ulcer ; Keratitis ; Trophozoites ; Ulcer

South Korea has been free from endemic malaria by P. vivax since the mid-1980s, but malaria infections, including military outbreak in 1995, have been increasing steadily in the soldiers serving near the western part of Demilitarized Zone(DMZ) since its first resurgence in 1993. We experinced 8 cases of delayed onset P. vivax malaria in young men who had never been abroad and had no history of blood transfusion or parenteral use of drug. All the patients had served near the western part of DMZ during their military life. They were admitted to Yeungnam University hospital due to cyclic fever with chills and the clinical symptoms were developed 2 months to 11months after discharge from military service. Peripheral blood smears showed typical ring forms and trophozoites of P. vivax in red blood cell. Patients were treated with hydroxychloroquine and primaquine showing rapid clinical and hematologic responses in all cases, but 2 cases were relapsed later. We presumed that theses cases were delayed onset of P. vivax infection resulted from the recent outbreak in the western part of DMZ, in 1995. Therefore, we reported theses cases to emphasize the need of active surveillance and prevention.
Blood Transfusion ; Chills ; Erythrocytes ; Fever ; Humans ; Hydroxychloroquine ; Korea ; Malaria ; Malaria, Vivax* ; Male ; Military Personnel ; Primaquine ; Trophozoites

This study was carried out to determine the pathogen-causing diarrhoea in sheep Ovis aries in the Qinghai Tibetan Plateau Area, China. A trophozoite was identified as species of ciliate alveolates infecting the sheep based on morphological characteristics examined by microscope. It was mostly spherical, colourless and transparent, with many vesicles. Macronucleus and contractile vacuoles could not be distinguished. Size of the trophozoite was 80–180×70–150 μm and its surface was covered with cilia. Molecular analysis based on sequences of 18S rRNA and ITS genes confirmed the ciliate species as Balantidium coli. According to the literature, there have been many epidemiological investigations of B. coli infection in pigs, monkeys and humans. To our knowledge, this was the first report of B. coli infections in sheep in the Qinghai Tibetan Plateau Area of China, or eleswhere around the world. Importantly, the sheep case was rare but raised our concern that B. coli may spread across species and expand its host range.
Balantidium ; China ; Cilia ; Haplorhini ; Host Specificity ; Humans ; Macronucleus ; Sheep ; Sheep, Domestic ; Swine ; Trophozoites ; Vacuoles

The cytological and ultrastructural findings of Pneumocystis carinii(PC) obtained from rats by bronchoalveolar lavage(BAL) are described. All developmental forms of the PC organisms were obtained in the lavage fluid. Ultrastructurally, the cysts were almost circular in shape, and were nearly devoid of surface tubular extensions. The wall of the cyst was composed of an unit membrane, and intermediate electron lucent layer and an external electron dense layer. The cysts frequently contained intracystic bodies, so called sporozoites. Occasionally empty or collapsed cysts with no intracystic bodies, and precysts were found. Trophozoites were variable in size and shape with abundant tubular extensions along the single electron dense pellicle. BAL is a useful method for concentrating the various morphologic forms of PC organisms, and is a rapid diagnostic method for PC pneumonia.
Animals ; Bronchoalveolar Lavage* ; Membranes ; Pneumocystis carinii* ; Pneumocystis* ; Pneumonia ; Pneumonia, Pneumocystis* ; Rats ; Sporozoites ; Therapeutic Irrigation ; Trophozoites

Encystation is an essential process for Acanthamoeba survival under nutrient-limiting conditions and exposure to drugs. The expression of several genes has been observed to increase or decrease during encystation. Epigenetic processes involved in regulation of gene expression have been shown to play a role in several pathogenic parasites. In the present study, we identified the protein arginine methyltransferase 5 (PRMT5), a known epigenetic regulator, in Acanthamoeba castellanii. PRMT5 of A. castellanii (AcPRMT5) contained domains found in S-adenosylmethionine-dependent methyltransferases and in PRMT5 arginine-N-methyltransferase. Expression levels of AcPRMT5 were increased during encystation of A. castellanii. The EGFP-PRMT5 fusion protein was mainly localized in the nucleus of trophozoites. A. castellanii transfected with siRNA designed against AcPRMT5 failed to form mature cysts. The findings of this study lead to a better understanding of epigenetic mechanisms behind the regulation of encystation in cyst-forming pathogenic protozoa.
Acanthamoeba castellanii ; Acanthamoeba* ; Epigenesis, Genetic ; Epigenomics ; Gene Expression Regulation ; Methyltransferases ; Parasites ; Protein-Arginine N-Methyltransferases* ; RNA, Small Interfering ; Trophozoites

Although rapid diagnosis of human babesiosis usually can be made by microscopic examination of thin and thick blood smears, differentiation between Babesia microti and Plasmodium falciparum can be quite difficult. The parasite is often not visualized in the early course of infection or in a partially treated case and the young trophozoites of these two organisms are similar. Recently, we experienced a case, which was thought as human babesiosis initially by microscopic examination of the Giemsa-stained thin blood smears, but was finally diagno-sed as P. falcifarum infection by indirect immunofluorescent antibody assay and polymerase chain reaction. The patient was treated successfully with quinine and clindamycin, which are effective in both infections. When differential diagnosis is difficult, we suggest combination therapy of quinine and clindamycin as an empirical regimen.
Animals ; Babesia microti ; Babesiosis ; Clindamycin* ; Diagnosis ; Diagnosis, Differential ; Humans ; Parasites ; Plasmodium falciparum ; Polymerase Chain Reaction ; Quinine* ; Trophozoites