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1.
Parasitol Res ; 119(11): 3755-3761, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32918603

RESUMO

Free-living amoeba (FLA) research in the Philippines is still in its infancy but has, by far, demonstrated the presence of potentially pathogenic species. Acanthamoeba may cause sight-threatening and central nervous system infections to humans, yet its epidemiologic distribution from local environmental sources is yet to be defined. The present study aimed to provide a baseline epidemiologic distribution of Acanthamoeba spp. in freshwater systems in the Philippines and establish potential pathogenicity of isolates through thermo-tolerance assay. A total of 63 water samples were collected from 13 freshwater systems all over the Philippine archipelago. The low-volume (50 ml) water samples were processed and cultured on non-nutrient agar lawned with Escherichia coli and observed for amoebic growth using light microscopy. Amoebic culture demonstrated 14.28% (9/63) positivity while further molecular testing of culture-positive plates using Acanthamoeba-specific primers demonstrated 100% (9/9) confirmation of Acanthamoeba species. Genotyping of Acanthamoeba isolates revealed T1, T3, T4, T5, T7, T11, and T15 genotypes. Thermo-tolerance assay demonstrated that T5 and T7 genotypes were potentially pathogenic strains. The evidence of environmental distribution of Acanthamoeba spp. in the freshwater systems in the Philippines and thermo-tolerance profile of isolates are significant aspects of amoeba study in public health and calls for initiatives in the dissemination of relevant information and the expansion of knowledge, awareness, and policies on pathogenic waterborne amoeba to mitigate, prevent, detect, and report cases of human infections.


Assuntos
Acanthamoeba/isolamento & purificação , Acanthamoeba/fisiologia , Água Doce/parasitologia , Acanthamoeba/genética , Acanthamoeba/crescimento & desenvolvimento , DNA de Protozoário/genética , Monitoramento Ambiental , Genótipo , Humanos , Filipinas , Termotolerância
2.
J Fr Ophtalmol ; 43(4): 330-333, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32151474

RESUMO

Acanthamoeba keratitis due to a genus of free-living amoebae is a severe corneal infection. Treatment of this disease is based on the combined use of antiseptics and other drugs, including azoles. We tested isavuconazole, the latest marketed azole, in vitro, against A. castellanii, A. lenticulata and A. hatchetti. Our results show that isavuconazole presents slight amoebistatic activity against A. castellanii trophozoites but no cysticidal activity. Isavuconazole could be used only in association for management of AK due to A. castellanii.


Assuntos
Ceratite por Acanthamoeba/parasitologia , Acanthamoeba/efeitos dos fármacos , Nitrilos/farmacologia , Piridinas/farmacologia , Triazóis/farmacologia , Acanthamoeba/classificação , Acanthamoeba/crescimento & desenvolvimento , Acanthamoeba/fisiologia , Ceratite por Acanthamoeba/tratamento farmacológico , Acanthamoeba castellanii/efeitos dos fármacos , Acanthamoeba castellanii/crescimento & desenvolvimento , Acanthamoeba castellanii/fisiologia , Animais , Relação Dose-Resposta a Droga , Humanos , Nitrilos/uso terapêutico , Encistamento de Parasitas/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Piridinas/uso terapêutico , Triazóis/uso terapêutico , Trofozoítos/efeitos dos fármacos
3.
Exp Parasitol ; 210: 107842, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31978393

RESUMO

Free-living amoebae of the genus Acanthamoeba have been associated with keratitis and encephalitis. Some factors related to their pathogenic potential have been described, including the release of hydrolytic enzymes, and the adhesion and phagocytosis processes. However, other factors such as their effect over the hemodynamics and microcirculation elements have not been fully investigated. This work determines the in vitro activity of potentially pathogenic environmental isolates of Acanthamoeba genotype T4 and T5 over erythrocytes and platelets. The hemolytic activity (dependent and independent of contact), as well as the production of ADP of ten environmental isolates of Acanthamoeba obtained from dental units, combined emergency showers, dust, and hospital water, were measured. Tests were carried out over erythrocytes in suspension and blood agar plates, incubated at 4 °C, room temperature and 37 °C. Erythrophagocytosis and platelet aggregation assays were also performed. Live trophozoites of all of the isolates tested showed a hemolytic activity that was temperature-dependent. Over erythrocytes in suspension, variable hemolysis percentages were obtained: a maximum of 41% and a minimum of 15%. Regarding hemolysis over agar plates, two patterns of hemolysis were observed: double and simple halos. Conditioned medium and crude extracts of trophozoites did not show hemolytic activity. Erythrophagocytosis by Acanthamoeba was also observed; however, no production of ADP was determined by the employed methodology.


Assuntos
Acanthamoeba/fisiologia , Plaquetas/parasitologia , Meio Ambiente , Eritrócitos/parasitologia , Acanthamoeba/classificação , Acanthamoeba/genética , Acanthamoeba/patogenicidade , Difosfato de Adenosina/metabolismo , Doenças Transmissíveis Emergentes/parasitologia , Meios de Cultivo Condicionados , Eritrócitos/fisiologia , Genótipo , Hemólise , Humanos , Fagocitose , Agregação Plaquetária , Temperatura , Trofozoítos/classificação , Trofozoítos/genética , Trofozoítos/patogenicidade , Trofozoítos/fisiologia
4.
Parasite Immunol ; 42(3): e12692, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31856305

RESUMO

The aim of this study was to evaluate the inflammation process that resulted from the inoculation of Wistar Rats with Acanthamoeba griffini, a virulent T3 Acanthamoeba genotype that produces keratitis. Haematoxylin and eosin, periodic acid stain, immunohistochemistry and morphometry were used to analyse tissues from rats of an Acanthamoeba keratitis (AK) model. Two weeks after inoculating the rats with A griffini trophozoites, the thickness of the stroma had diminished, followed by an increase in thickness at 4 weeks. At the latter time, an abundance of inflammatory infiltrate cells was observed, some found to express IL-1ß, IL-10 and/or caspase 3. Intercellular adhesion molecule-1 was expressed in corneal blood vessels amid the abundant vascularization characteristic of the development of AK. Through an immunohistochemical technique, trophozoites were detected at 2 and 4 weeks post-inoculation. By 8 weeks, there were a low number of trophozoites and cysts and the corneas of infected rats were similar in thickness to those of the controls. Thus, the rats were capable of healing experimental AK in the present rat model. Diverse immunological mechanisms regulated the inflammatory process in acute AK induced by A griffini in a murine model.


Assuntos
Ceratite por Acanthamoeba/patologia , Acanthamoeba/fisiologia , Acanthamoeba/classificação , Ceratite por Acanthamoeba/imunologia , Animais , Apoptose , Caspase 3/análise , Córnea/patologia , Modelos Animais de Doenças , Feminino , Humanos , Molécula 1 de Adesão Intercelular/análise , Interleucina-10/análise , Interleucina-1beta/análise , Camundongos , Ratos , Ratos Wistar , Trofozoítos/fisiologia
5.
BMC Res Notes ; 12(1): 746, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730018

RESUMO

OBJECTIVE: Rhizoctonia solani is a soil-borne fungal pathogen of many important crop plants. In rice, R. solani causes sheath blight disease, which results in devastating grain yield and quality losses. Few methods are available to control this pathogen and classic single gene resistance mechanisms in rice plants have not been identified. We hypothesize that alternate means of control are available in the environment including free-living amoebae. Amoebae are soil-, water- and air-borne microorganisms that are predominantly heterotrophic. Many amoeba species are mycophagous, and several harm their prey using mechanisms other than phagocytosis. Here, we used light and scanning electron microscopy to survey the interactions of R. solani with four amoeba species, with the goal of identifying amoebae species with potential for biocontrol. RESULTS: We observed a wide range of responses during interactions of R. solani with four different free-living amoebae. Two Acanthamoeba species encyst in co-cultures with R. solani at higher rates than medium without R. solani. Vermamoeba vermiformis (formerly Hartmanella vermiformis) attach to R. solani mycelium and are associated with mycelial shriveling and perforations of fungal cell walls, indicating an antagonistic interaction. No phenotypic changes were observed in co-cultures of Dictyostelium discoideum and R. solani.


Assuntos
Acanthamoeba/fisiologia , Antibiose , Hartmannella/fisiologia , Micélio/ultraestrutura , Controle Biológico de Vetores/métodos , Rhizoctonia/ultraestrutura , Acanthamoeba/microbiologia , Acanthamoeba/ultraestrutura , Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Parede Celular/ultraestrutura , Técnicas de Cocultura , Dictyostelium/microbiologia , Dictyostelium/fisiologia , Dictyostelium/ultraestrutura , Hartmannella/microbiologia , Hartmannella/ultraestrutura , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Micélio/patogenicidade , Oryza/microbiologia , Doenças das Plantas/prevenção & controle , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/crescimento & desenvolvimento , Rhizoctonia/patogenicidade
6.
Korean J Parasitol ; 57(4): 341-357, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31533401

RESUMO

Acanthamoeba, one of free-living amoebae (FLA), remains a high risk of direct contact with this protozoan parasite which is ubiquitous in nature and man-made environment. This pathogenic FLA can cause sight-threatening amoebic keratitis (AK) and fatal granulomatous amoebic encephalitis (GAE) though these cases may not commonly be reported in our clinical settings. Acanthamoeba has been detected from different environmental sources namely; soil, water, hot-spring, swimming pool, air-conditioner, or contact lens storage cases. The identification of Acanthamoeba is based on morphological appearance and molecular techniques using PCR and DNA sequencing for clinico-epidemiological purposes. Recent treatments have long been ineffective against Acanthamoeba cyst, novel anti-Acanthamoeba agents have therefore been extensively investigated. There are efforts to utilize synthetic chemicals, lead compounds from medicinal plant extracts, and animal products to combat Acanthamoeba infection. Applied nanotechnology, an advanced technology, has shown to enhance the anti-Acanthamoeba activity in the encapsulated nanoparticles leading to new therapeutic options. This review attempts to provide an overview of the available data and studies on the occurrence of pathogenic Acanthamoeba among the Association of Southeast Asian Nations (ASEAN) members with the aim of identifying some potential contributing factors such as distribution, demographic profile of the patients, possible source of the parasite, mode of transmission and treatment. Further, this review attempts to provide future direction for prevention and control of the Acanthamoeba infection.


Assuntos
Acanthamoeba , Amebíase/epidemiologia , Acanthamoeba/classificação , Acanthamoeba/isolamento & purificação , Acanthamoeba/fisiologia , Amebíase/diagnóstico , Amebíase/terapia , Amebíase/transmissão , Ásia Sudeste/epidemiologia , Solo/parasitologia , Água/parasitologia
7.
Sci Rep ; 9(1): 12821, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492880

RESUMO

The role of topical corticosteroids in management of Acanthamoeba keratitis (AK) remains controversial. Using a rabbit AK model, we investigated whether corticosteroid use is a risk factor of AK. Acanthamoeba (1 × 105/ml) was incubated with two densities of P. aeruginosa (PA; high-PA: 1 × 108/ml, low-PA: 3 × 105/ml) before corneal inoculation. Rabbit corneas were inoculated with Acanthamoeba alone or Acanthamoeba plus PA and administered levofloxacin and betamethasone sodium phosphate (BSP) eye drops for 5 or 7 days. Infected rabbit eyes were evaluated for clinical score and Acanthamoeba by histological examination. Acanthamoeba alone and BSP treatment did not produce keratitis. Corneas inoculated with Acanthamoeba plus low-PA treated immediately with levofloxacin and BSP remained clear with few infiltrates. Corneas inoculated with Acanthamoeba plus low-PA treated with levofloxacin immediately and BSP 12 h later developed severe keratitis. Corneas inoculated with Acanthamoeba plus high-PA treated immediately with levofloxacin and BSP also developed severe keratitis. Acanthamoebae were detected by PAS staining in corneas inoculated with Acanthamoeba plus high-PA treated with levofloxacin and BSP. Topical corticosteroids have the potential to aggravate AK when cornea is infected by Acanthamoeba with a critical number of bacteria or when corticosteroids are given after infection has established by Acanthamoeba with small number of bacteria.


Assuntos
Ceratite por Acanthamoeba/induzido quimicamente , Ceratite por Acanthamoeba/microbiologia , Acanthamoeba/fisiologia , Corticosteroides/efeitos adversos , Córnea/patologia , Soluções Oftálmicas/efeitos adversos , Pseudomonas aeruginosa/fisiologia , Animais , Antibacterianos/efeitos adversos , Betametasona/efeitos adversos , Córnea/microbiologia , Humanos , Coelhos
8.
Neuropathology ; 39(4): 251-258, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31243796

RESUMO

Over 600 cases of amoebic encephalitis caused by pathogenic free-living amoebas (Balamuthia mandrillaris, Acanthamoeba spp., and Naegleria fowleri) have been reported worldwide, and in Japan, 24 cases have been reported from the first case in 1976 up to 2018. Among these cases, 18 were caused by B. mandrillaris, four by Acanthamoeba spp., one by N. fowleri, and one was of unknown etiology. Additionally, eight cases were diagnosed with encephalitis due to pathogenic free-living amoebas before death, but only three cases were successfully treated. Unfortunately, all other cases were diagnosed by autopsy. These facts indicate that an adequate diagnosis is difficult, because encephalitis due to pathogenic free-living amoebas does not show typical symptoms or laboratory findings. Moreover, because the number of cases is limited, other cases might have been missed outside of those diagnosed by autopsy. Cases of encephalitis caused by B. mandrillaris have been reported from all over Japan, with B. mandrillaris recently isolated from soil in Aomori prefecture. Therefore, encephalitis caused by pathogenic free-living amoebas should be added to the differential diagnosis of encephalitis patients.


Assuntos
Acanthamoeba/fisiologia , Amebíase/parasitologia , Balamuthia mandrillaris/fisiologia , Infecções Protozoárias do Sistema Nervoso Central/parasitologia , Encefalite/parasitologia , Naegleria fowleri/fisiologia , Infecções Protozoárias do Sistema Nervoso Central/diagnóstico , Encefalite/diagnóstico , Humanos , Japão
9.
Parasitol Res ; 118(8): 2443-2454, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31144032

RESUMO

Acanthamoeba keratitis (AK) is a devastating, painful corneal infection, which may lead to loss of vision. The development of resistance and failure of the currently used drugs represent a therapeutic predicament. Thus, novel therapies with lethal effects on resistant Acanthamoeba are necessary to combat AK. In the present study, the curative effect of Nigella sativa aqueous extract (N. sativa) and chitosan nanoparticles (nCs) and both agents combined were assessed in experimentally induced AK. All inoculated corneas developed varying grades of AK. The study medications were applied on the 5th day postinoculation and were evaluated by clinical examination of the cornea and cultivation of corneal scraps. On the 10th day posttreatment, a 100% cure of AK was obtained with nCs (100 µg/ml) in grades 1 and 2 of corneal opacity as well as with N. sativa 60 mg/ml-nCs 100 µg/ml in grades 1, 2, and 3 of corneal opacity, highlighting a possible synergistic effect. On the 15th day posttreatment, a 100% cure was reached with N. sativa aqueous extract (60 mg/ml). Moreover, on the 20th day posttreatment, N. sativa (30 mg/ml) provided a cure rate of 87.5%, while nCs (50 µg/ml) as well as N. sativa 30 mg/ml-nCs 50 µg/ml yielded a cure rate of 75%; the lowest percentage of cure (25%) was obtained with chlorhexidine (0.02%), showing a non-significant difference compared to the parasite control. The clinical outcomes were in agreement with the results of corneal scrap cultivation. The results of the present study demonstrate the effectiveness of N. sativa aqueous extract and nCs (singly or combined) when used against AK, and these agents show potential for the development of new, effective, and safe therapeutic alternatives.


Assuntos
Ceratite por Acanthamoeba/tratamento farmacológico , Antiprotozoários/administração & dosagem , Nigella sativa/química , Extratos Vegetais/administração & dosagem , Acanthamoeba/efeitos dos fármacos , Acanthamoeba/fisiologia , Ceratite por Acanthamoeba/parasitologia , Adulto , Animais , Antiprotozoários/química , Quitosana/química , Quitosana/farmacologia , Quitosana/uso terapêutico , Clorexidina/farmacologia , Córnea/parasitologia , Feminino , Humanos , Masculino , Nanopartículas/química , Extratos Vegetais/química , Ratos , Resultado do Tratamento
10.
Exp Parasitol ; 200: 48-54, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30917916

RESUMO

Free-living amoebae belong to the genus Acanthamoeba; can feed on microbial population by phagocytosis, and with the capability to act as a reservoir and a vehicle of microorganisms to susceptible host. Therefore, the role of endosymbiosis in the pathogenesis of Acanthamoeba is complex and not fully understood. The aim of the present study was to identify bacterial, fungal, and human adenovirus (HADV) endosymbionts as well as evaluating the endosymbionts role of such organisms in the pathogenesis of Acanthamoeba in keratitis patients living in Iran. Fifteen Acanthamoeba (T4 genotype) isolates were recovered from corneal scrapes and contact lenses of patients with keratitis. Cloning and purification was performed for all isolate. Gram staining was performed to identify bacterial endosymbionts. DNA extraction, PCR, and nested PCR was set up to identify endosymbiont of amoeba. Evaluation of pathogenicity was conducted by osmo-tolerance and thermo-tolerance assays and cell culture, and then CPE (cytopathic effect) was survey. Statistical analysis was used between Acanthamoeba associated endosymbionts and Acanthamoeba without endosymbiont at 24, 48, 72, and 96 h. A p value < 0.05 was considered as significant, statistically. A total of 9 (60%) Acanthamoeba (T4 genotypes) isolates were successfully cloned for detecting microorganism endosymbionts. The only isolate negative for the presence of endosymbiont was ICS9. ICS7 (Pseudomonas aeruginosa, Aspergillus sp., and human adenovirus endosymbionts) and ICS2 (Escherichia coli endosymbiont) isolates were considered as Acanthamoeba associated endosymbionts. ICS7 and ICS2 isolates were highly pathogen whereas ICS9 isolate showed low pathogenicity in pathogenicity evaluated. Positive CPE for ICS7 and ICS2 isolates and negative CPE for ICS9 isolate were observed in cell culture. The average number of cells, trophozoites, and cysts among ICS7, ICS2, and ICS9 isolates at 24, 48, 72, and 96 h was significant. This is the first survey on microbial endosymbionts of Acanthamoeba in keratitis patients of Iran, and also the first report of Aspergillus sp, Achromobacter sp., Microbacterium sp., Brevibacillus sp, Brevundimonas sp and Mastadenovirus sp in Acanthamoeba as endosymbionts. Our study demonstrated that microbial endosymbionts can affect the pathogenicity of Acanthamoeba; however, further research is required to clarify the exact pattern of symbiosis, in order to modify treatment protocol.


Assuntos
Ceratite por Acanthamoeba/complicações , Acanthamoeba/fisiologia , Adenovírus Humanos/isolamento & purificação , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Simbiose , Acanthamoeba/isolamento & purificação , Acanthamoeba/microbiologia , Acanthamoeba/patogenicidade , Adenovírus Humanos/genética , Adenovírus Humanos/fisiologia , Animais , Bactérias/genética , Chlorocebus aethiops , Clonagem Molecular , Doenças Transmissíveis/microbiologia , Doenças Transmissíveis/transmissão , Lentes de Contato/parasitologia , Córnea/parasitologia , Reservatórios de Doenças , Fungos/genética , Humanos , Irã (Geográfico) , Reação em Cadeia da Polimerase , Células Vero , Virulência
11.
Exp Parasitol ; 199: 24-29, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30796912

RESUMO

The genus Acanthamoeba, which may cause different infections in humans, occurs widely in the environment. Lung inflammation caused by these parasites induces pulmonary pathological changes such as pulmonary necrosis, peribronchial plasma cell infiltration, moderate desquamation of alveolar cells and partial destruction of bronchial epithelial cells, and presence of numerous trophozoites and cysts among inflammatory cells. The aim of this study was to assess the influence of plant extracts from Artemisia annua L. on expression of the toll-like receptors TLR2 and TLR4 in lungs of mice with acanthamoebiasis. A. annua, which belongs to the family Asteraceae, is an annual plant that grows wild in Asia. In this study, statistically significant changes of expression of TLR2 and TLR4 were demonstrated. In the lungs of infected mice after application of extract from A. annua the expression of TLRs was observed mainly in bronchial epithelial cells, pneumocytes (to a lesser extent during the outbreak of infection), and in the course of high general TLR expression. TLR4 in particular was also visible in stromal cells of lung parenchyma. In conclusion, we confirmed that a plant extract of A. annua has a modulatory effect on components of the immune system such as TLR2 and TLR4.


Assuntos
Acanthamoeba/fisiologia , Amebíase/tratamento farmacológico , Artemisia annua/química , Pneumopatias Parasitárias/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Receptores Toll-Like/metabolismo , Amebíase/metabolismo , Animais , DNA Complementar/metabolismo , Imuno-Histoquímica , Pulmão/parasitologia , Pulmão/patologia , Pneumopatias Parasitárias/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/farmacologia , RNA Mensageiro/metabolismo , RNA de Protozoário/genética , RNA de Protozoário/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa , Receptor 2 Toll-Like/efeitos dos fármacos , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/efeitos dos fármacos , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Receptores Toll-Like/efeitos dos fármacos , Receptores Toll-Like/genética
12.
Parasitol Res ; 117(10): 3333-3336, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30094540

RESUMO

Free-living amoebae (FLA) are protozoa ubiquitously found in nature. As some species or strains of these FLA are pathogenic for humans and animals, they represent objects of medical and parasitological research worldwide. Storage of valuable FLA strains in laboratories is often time- and energy-consuming and expensive. The shipment of such strains as frozen stocks is cumbersome and challenging in terms of cooling requirements as well as of transport regulations. To overcome these difficulties and challenges in maintenance and transport, we present a new method to generate lyophilised samples of non-cyst-forming FLA (Ripella (Vannella) spp.) and cyst-forming FLA (Acanthamoeba spp.) strains which guarantees a simple mechanism for long-term storage at ambient temperature, as well as easy handling and/or shipment. The survival rate of all FLA lyophilisates after short-term storage (2 months) was comparable to the survival rate of freeze cultures of the respective strains. Furthermore, the viability of Acanthamoeba spp. cysts after storage for 29 months was 20 to 40% following lyophilisation and rehydration, with strain variation.


Assuntos
Acanthamoeba/fisiologia , Amebozoários/fisiologia , Preservação Biológica/métodos , Acanthamoeba/química , Amebozoários/química , Animais , Temperatura
13.
Acta Microbiol Immunol Hung ; 65(1): 73-79, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29471697

RESUMO

Acanthamoeba has a worldwide distribution in the environment and it is capable of causing a painful sight-threatening disease of the cornea designated as Acanthamoeba keratitis (AK). Nowadays, the cases of AK have surged all over the world along with its disease burden due to increasing use of contact lenses used not only for optical correction but also for cosmetic purposes. In our present work, epithelial abrasion of a 27-year-old female soft contact lens wearer with keratitis was examined. Genotype identification was carried out with a real-time fluorescence resonance energy transfer polymerase chain reaction (PCR) assay based on sequence analysis of the 18S rRNA gene. Genotyping allowed the identification of a T8 group isolate. The analysis confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK from human samples. Acanthamoeba T8 should be considered as potential causative organism in keratitis in human.


Assuntos
Ceratite por Acanthamoeba/diagnóstico , Acanthamoeba/isolamento & purificação , Amebíase/diagnóstico , Acanthamoeba/classificação , Acanthamoeba/genética , Acanthamoeba/fisiologia , Ceratite por Acanthamoeba/parasitologia , Adulto , Amebíase/parasitologia , Córnea/parasitologia , Feminino , Genótipo , Humanos , Filogenia
14.
Parasit Vectors ; 11(1): 26, 2018 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-29316961

RESUMO

Acanthamoeba spp. are protist pathogens and causative agents of serious infections including keratitis and granulomatous amoebic encephalitis. Its ability to convert into dormant and highly resistant cysts form limits effectiveness of available therapeutic agents and presents a pivotal challenge for drug development. During the cyst stage, Acanthamoeba is protected by the presence of hardy cyst walls, comprised primarily of carbohydrates and cyst-specific proteins, hence synthesis inhibition and/or degradation of cyst walls is of major interest. This review focuses on targeting of Acanthamoeba cysts by identifying viable therapeutic targets.


Assuntos
Acanthamoeba/efeitos dos fármacos , Amebíase/epidemiologia , Amebíase/prevenção & controle , Antiprotozoários/isolamento & purificação , Antiprotozoários/farmacologia , Descoberta de Drogas/métodos , Esporos de Protozoários/efeitos dos fármacos , Acanthamoeba/fisiologia , Descoberta de Drogas/tendências , Humanos , Esporos de Protozoários/fisiologia
15.
J Korean Med Sci ; 33(4): e26, 2018 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-29318793

RESUMO

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.


Assuntos
Acanthamoeba/fisiologia , Lentes de Contato/parasitologia , Desinfetantes/farmacologia , Humanos , Microscopia Eletrônica de Varredura , Trofozoítos/efeitos dos fármacos , Trofozoítos/fisiologia
16.
Int J Mol Sci ; 19(1)2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29301283

RESUMO

Little is known about the pathomechanism of pulmonary infections caused by Acanthamoeba sp. Therefore, the aim of this study was to determine whether Acanthamoeba sp. may affect the expression and activity of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), resulting in the altered levels of their main products, prostaglandins (PGE2) and thromboxane B2 (TXB2), in lungs of immunocompetent or immunosuppressed hosts. Acanthamoeba sp. induced a strong expression of COX-1 and COX-2 proteins in the lungs of immunocompetent mice, which, however, did not result in significant differences in the expression of PGE2 and TXB2. Our immunohistochemical analysis showed that immunosuppression induced by glucocorticoids in Acanthamoeba sp.-infected mice caused a decrease in COX-1 and COX-2 (not at the beginning of infection) in lung tissue. These results suggest that similar to COX-2, COX-1 is an important mediator of the pathophysiology in experimental pulmonary acanthamoebiasis. We suggest that the signaling pathways important for Acanthamoeba sp. induction of lung infection might interact with each other and depend on the host immune status.


Assuntos
Acanthamoeba/enzimologia , Acanthamoeba/fisiologia , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Pulmão/imunologia , Pulmão/parasitologia , Animais , Peso Corporal , Dinoprostona/metabolismo , Humanos , Pulmão/enzimologia , Pulmão/patologia , Pneumopatias Parasitárias/enzimologia , Pneumopatias Parasitárias/parasitologia , Masculino , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Tamanho do Órgão , Tromboxano B2/metabolismo
17.
Microb Pathog ; 114: 1-7, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29155010

RESUMO

Mycobacterium ulcerans, a decaying Mycobacterium marinum derivative is responsible for Buruli ulcer, a notifiable non-contagious disabling infection highly prevalent in some West African countries. Aquatic environments are suspected to host M. ulcerans, however, the exact reservoirs remain unknown. While M. marinum was found to resist amoebal microbicidal activities, this remains unknown for M. ulcerans. In this study M. ulcerans was co-cultured with the moderately halophile Acanthamoeba griffini at 30 °C to probe this tropical amoeba as a potential reservoir for M. ulcerans. In triplicate experiments, we observed engulfment of M. ulcerans by A. griffini trophozoites, followed by an unexpected significant difference of 98.4% (day 1), 99.5% (day 2), 99.5% (day 3) and 99.9% (day 7) between the number of intra-amoebal mycobacteria detected by PCR and the number of viable intra-amoebal mycobacteria measured by 10-week culture. Further encystment revealed only one Mycobacterium organism for 150 A. griffini cysts observed by electron microscopy and the culture of excysted amoebae remained sterile. In conclusion, these data install M. ulcerans as susceptible to A. griffini microbicidal activities rendering this amoeba species an unlikely host of M. ulcerans in natural environments.


Assuntos
Acanthamoeba/microbiologia , Acanthamoeba/fisiologia , Técnicas de Cocultura/métodos , Mycobacterium ulcerans/fisiologia , Amoeba/microbiologia , Úlcera de Buruli/microbiologia , DNA Bacteriano , Reservatórios de Doenças/microbiologia , Microbiologia Ambiental , Viabilidade Microbiana , Mycobacterium ulcerans/crescimento & desenvolvimento
18.
Ann Parasitol ; 64(4): 285­297, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30710471

RESUMO

Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and keratitis. The purpose of this study was to evaluate the prevalence and genotyping of Acanthamoeba spp. from different water and soil sources in Iran. Six English language and four Persian language databases were searched to identify studies published from March 2005 to October 2016. Random effect model and Stats Direct statistical software was used for the meta-analysis. This review resulted in a total 34 articles meeting the including criteria. The overall prevalence rate of Acanthamoeba spp. among the 1850 water and soil samples in Iran with using random-effect model was estimated 42.7%. The genotyping results of the Acanthamoeba isolates showed that T4 (81.2%) was a predominant strain in Iran. In addition, other genotypes, T2, T3, T4, T5, T6, T11, T13, T15, mixed T3/T4 and mixed T2/T6, were obtained in the environmental samples of Iran. This study may be the first systematic review and meta-analysis of Acanthamoeba prevalence and genotyping in different environmental sources of Iran. Knowledge about wide distribution of Acanthamoeba T4 in the environmental sources may help physicians to manage the patients and susceptible persons in Iran.


Assuntos
Acanthamoeba , Genótipo , Solo , Água , Acanthamoeba/genética , Acanthamoeba/fisiologia , Ceratite por Acanthamoeba , Humanos , Irã (Geográfico) , Solo/parasitologia , Água/parasitologia
19.
Ann Parasitol ; 64(4): 299-308, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30720249

RESUMO

Amoebas from the genus Acanthamoeba are cosmopolitan organisms, which can exist as free-living organisms and as parasites within host tissue. Acanthamoeba infection present a serious risk to human health and are characterized by high mortality, especially in immunocompromised individuals. These protozoa are the etiological factors of granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). They can also live in the lungs, adrenals glands, nose, throat, and bones of the host. Furthermore, the amoebas can be vectors of pathogenic bacteria. Acanthamoeba infection caused is a serious clinical problem mainly due to limited progress in diagnostics and treatment of this infection, which is associated with insufficient knowledge of pathogenesis, pathophysiology and the host immune response against Acanthamoeba antigens. This review study presents the biology of Acanthamoeba sp. as well as pathogenicity, diagnostics, and treatment of amoebas infections. It also presents data, including experimental results, concerning pathogenic properties and the host's immunology response against Acanthamoeba sp.


Assuntos
Acanthamoeba , Amebíase , Acanthamoeba/patogenicidade , Acanthamoeba/fisiologia , Amebíase/imunologia , Amebíase/parasitologia , Humanos , Hospedeiro Imunocomprometido
20.
Ann Parasitol ; 64(4): 317-322, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30720969

RESUMO

Acanthamoeba species are ubiquitous in natural and man-made environments worldwide; some strains are able to colonize human eyes as facultative parasites. It has been shown that environmental and clinical isolates/species of Acanthamoeba vary in their pathogenicity. In this study we examine and compare the in vitro effects of the changing temperature on the population dynamics of subsequent amoebic strains. Identification of Acanthamoeba strain by morphological and molecular methods and temperature assays were performed. Monitoring of the corneal and environmental strains showed changes in population densities and a termo-tolerance correlating with pathogenicity of amoebae. Comparative assessment of results indicated differences in viability of amoebic populations in exponential growth phase in vitro cultivation. The increased awareness of the threat is needed for better understanding of impact of factors examined on pathogenesis in human infected with Acanthamoeba strains.


Assuntos
Acanthamoeba/fisiologia , Acanthamoeba/patogenicidade , Temperatura , Acanthamoeba/citologia , Acanthamoeba/genética , Amebíase/parasitologia , Biomarcadores , Humanos , Especificidade da Espécie , Virulência/fisiologia
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