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Soleymani E, Fakhar M, Davoodi L, Motavallihaghi S, Sharifpour A, Maghsood AH. Isolation, characterization, and pathogenicity assay of Acanthamoeba and its endosymbionts in respiratory disorders and COVID-19 hospitalized patients, northern Iran. Exp Parasitol 2024; 262:108774. [PMID: 38754618 DOI: 10.1016/j.exppara.2024.108774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 04/16/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
Acanthamoeba spp., are common free-living amoebae found in nature that can serve as reservoirs for certain microorganisms. The SARS-CoV-2 virus is a newly emerged respiratory infection, and the investigation of parasitic infections remains an area of limited research. Given that Acanthamoeba can act as a host for various endosymbiotic microbial pathogens and its pathogenicity assay is not fully understood, this study aimed to identify Acanthamoeba and its bacterial and fungal endosymbionts in patients with chronic respiratory disorders and hospitalized COVID-19 patients in northern Iran. Additionally, a pathogenicity assay was conducted on Acanthamoeba isolates. Urine, nasopharyngeal swab, and respiratory specimens were collected from two groups, and each sample was cultured on 1.5% non-nutrient agar medium. The cultures were then incubated at room temperature and monitored daily for a period of two weeks. Eight Acanthamoeba isolates were identified, and PCR was performed to confirm the presence of amoebae and identify their endosymbionts. Four isolates were found to have bacterial endosymbionts, including Stenotrophomonas maltophilia and Achromobacter sp., while two isolates harbored fungal endosymbionts, including an uncultured fungus and Gloeotinia sp. In the pathogenicity assay, five isolates exhibited a higher degree of pathogenicity compared to the other three. This study provides significant insights into the comorbidity of acanthamoebiasis and COVID-19 on a global scale, and presents the first evidence of Gloeotinia sp. as a fungal endosymbiont. Nevertheless, further research is required to fully comprehend the symbiotic patterns and establish effective treatment protocols.
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Affiliation(s)
- Eissa Soleymani
- Department of Medical Parasitology and Mycology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mahdi Fakhar
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Lotfollah Davoodi
- Department of Infectious Diseases, Antimicrobial Resistance Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyedmousa Motavallihaghi
- Department of Medical Parasitology and Mycology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Ali Sharifpour
- Department of Internal Ward, Pulmonary and Critical Care Division, Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran
| | - Amir Hossein Maghsood
- Department of Medical Parasitology and Mycology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
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Petrillo F, Tortori A, Vallino V, Galdiero M, Fea AM, De Sanctis U, Reibaldi M. Understanding Acanthamoeba Keratitis: An In-Depth Review of a Sight-Threatening Eye Infection. Microorganisms 2024; 12:758. [PMID: 38674702 PMCID: PMC11052265 DOI: 10.3390/microorganisms12040758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a rare but potentially sight-threatening corneal infection caused by the Acanthamoeba parasite. This microorganism is found ubiquitously in the environment, often in freshwater, soil, and other sources of moisture. Despite its low incidence, AK presents significant challenges due to delayed diagnosis and the complex nature of therapeutic management. Early recognition is crucial to prevent severe ocular complications, including corneal ulceration and vision loss. Diagnostic modalities and treatment strategies may vary greatly depending on the clinical manifestation and the available tools. With the growing reported cases of Acanthamoeba keratitis, it is essential for the ophthalmic community to thoroughly understand this condition for its effective management and improved outcomes. This review provides a comprehensive overview of AK, encompassing its epidemiology, risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment.
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Affiliation(s)
- Francesco Petrillo
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Antonia Tortori
- Ophthalmology Unit, Surgery Department, Piacenza Hospital, 29121 Piacenza, Italy;
| | - Veronica Vallino
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Marilena Galdiero
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 81100 Naples, Italy;
| | - Antonio M. Fea
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Ugo De Sanctis
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Michele Reibaldi
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
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Raghavan A, Rammohan R. Acanthamoeba keratitis - A review. Indian J Ophthalmol 2024; 72:473-482. [PMID: 38454853 PMCID: PMC11149514 DOI: 10.4103/ijo.ijo_2627_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/23/2023] [Indexed: 03/09/2024] Open
Abstract
This is a comprehensive review after a thorough literature search in PubMed-indexed journals, incorporating current information on the pathophysiology, clinical features, diagnosis, medical and surgical therapy, as well as outcomes of Acanthamoeba keratitis (AK). AK is a significant cause of ocular morbidity, and early diagnosis with timely institution of appropriate therapy is the key to obtaining good outcomes. The varied presentations result in frequent misdiagnosis, and co-infections can increase the morbidity of the disease. The first line of therapy continues to be biguanides and diamidines, with surgery as a last resort.
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Affiliation(s)
- Anita Raghavan
- Cornea & Refractive Surgery, Department of Microbiology, Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology, Coimbatore, Tamil Nadu, India
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Messina M, Tucci D, Mocini S, Marruso V, Crotti S, Said D, Dua HS, Cagini C. Increasing incidence of contact-lens-related Acanthamoeba keratitis in a tertiary ophthalmology department in an Italian population. Eur J Ophthalmol 2024:11206721241242165. [PMID: 38509758 DOI: 10.1177/11206721241242165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
PURPOSE The purpose of this paper is to report the increasing incidence of contact-lens related Acanthamoeba keratitis (AK) in a tertiary ophthalmology department in Umbria, central Italy. METHODS Observational and retrospective case series were carried out. A total of nine eyes with a diagnosis of AK were examined. All patients underwent a full slit lamp examination, in vivo confocal microscopy (IVCM) and corneal scraping. The IVCM was repeated at one and two-week and at one, three and six-month intervals. Samples of domestic tap water were also examined for PCR analysis. Patients were treated with levofloxacin0,5%, Polyhexamethylene biguanide 0.02%, and Propamidine Isetionate0,1%. RESULTS All patients were contact lens wearers. The average patient age was 27.75 (range 18-45), with three men and five women. The main clinical features were ciliary congestion, diffuse epitheliopathy with punctuated keratitis, multiple, small sub-epithelial, greyish, corneal infiltrates with epithelial defect, pseudodendritic corneal lesions, perineural infiltrates, corneal stromal cellularity, and stromal infiltrates. IVCM was indicative of Acanthamoeba in seven out of the nine eyes. All the positive IVCM images were section images showing double walled, bright-spot cysts with a clear chain-like arrangement of five or more cysts identified in three of the patients. PCR analysis of the water was negative in all cases. CONCLUSION Although PCR is the most common method used, the increased incidence of AK could mainly be related to a proper IVCM interpretation. A broad-spectrum antibiotic, such as levofloxacin might play a role in the early treatment of AK reducing the virulence of the amoeba.
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Affiliation(s)
- Marco Messina
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Davide Tucci
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Stefano Mocini
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Virginia Marruso
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Silvia Crotti
- Diagnostic Laboratory, Sperimental Zooprophylactic Institute of Umbria and Marche "Togo Rosati", Perugia, Italy
| | - Dalia Said
- Department of Ophthalmology, Section of Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Harminder Singh Dua
- Department of Ophthalmology, Section of Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Carlo Cagini
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
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Pang J, Wei Z, Wang L, Guo X, Chen Q, Wei Y, Peng Y, Zhang Z, Zhang Y, Liu J, Cheng Z, Wang Z, Zhang Y, Chen K, Xu X, Lu X, Liang Q. Acanthamoeba Keratitis in China: Genotypic and Clinical Correlations. Transl Vis Sci Technol 2024; 13:5. [PMID: 38329750 PMCID: PMC10860683 DOI: 10.1167/tvst.13.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/31/2023] [Indexed: 02/09/2024] Open
Abstract
Purpose To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients. Methods This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed. Results In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013). Conclusions In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D. Translational Relevance This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
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Affiliation(s)
- Jinding Pang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhenyu Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Leying Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaoyan Guo
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qiankun Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuan Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yan Peng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zijun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuheng Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiamin Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhen Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhiqun Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kexin Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xizhan Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinxin Lu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Haapanen S, Barker H, Carta F, Supuran CT, Parkkila S. Novel Drug Screening Assay for Acanthamoeba castellanii and the Anti-Amoebic Effect of Carbonic Anhydrase Inhibitors. J Med Chem 2024; 67:152-164. [PMID: 38150360 PMCID: PMC10788897 DOI: 10.1021/acs.jmedchem.3c01020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
Acanthamoeba castellanii is an amoeba that inhabits soil and water in every part of the world. Acanthamoeba infection of the eye causes keratitis and can lead to a loss of vision. Current treatment options are only moderately effective, have multiple harmful side effects, and are tedious. In our study, we developed a novel drug screening method to define the inhibitory properties of potential new drugs against A. castellanii in vitro. We found that the clinically used carbonic anhydrase inhibitors, acetazolamide, ethoxzolamide, and dorzolamide, have promising antiamoebic properties.
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Affiliation(s)
- Susanna Haapanen
- Faculty
of Medicine and Health Technology, Tampere
University, FI-33520 Tampere, Finland
| | - Harlan Barker
- Faculty
of Medicine and Health Technology, Tampere
University, FI-33520 Tampere, Finland
- Fimlab
Ltd, Tampere University Hospital, FI-33520 Tampere, Finland
| | - Fabrizio Carta
- Neurofarba
Department, Sezione di Chimica Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via U. Schiff 6, Sesto Fiorentino, I-50019 Firenze, Italy
| | - Claudiu T. Supuran
- Neurofarba
Department, Sezione di Chimica Farmaceutica e Nutraceutica, Università degli Studi di Firenze, Via U. Schiff 6, Sesto Fiorentino, I-50019 Firenze, Italy
| | - Seppo Parkkila
- Faculty
of Medicine and Health Technology, Tampere
University, FI-33520 Tampere, Finland
- Fimlab
Ltd, Tampere University Hospital, FI-33520 Tampere, Finland
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Rayamajhee B, Willcox M, Sharma S, Mooney R, Petsoglou C, Badenoch PR, Sherchan S, Henriquez FL, Carnt N. Zooming in on the intracellular microbiome composition of bacterivorous Acanthamoeba isolates. ISME COMMUNICATIONS 2024; 4:ycae016. [PMID: 38500701 PMCID: PMC10945361 DOI: 10.1093/ismeco/ycae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/29/2023] [Accepted: 01/22/2024] [Indexed: 03/20/2024]
Abstract
Acanthamoeba, a free-living amoeba in water and soil, is an emerging pathogen causing severe eye infection known as Acanthamoeba keratitis. In its natural environment, Acanthamoeba performs a dual function as an environmental heterotrophic predator and host for a range of microorganisms that resist digestion. Our objective was to characterize the intracellular microorganisms of phylogenetically distinct Acanthamoeba spp. isolated in Australia and India through directly sequencing 16S rRNA amplicons from the amoebae. The presence of intracellular bacteria was further confirmed by in situ hybridization and electron microscopy. Among the 51 isolates assessed, 41% harboured intracellular bacteria which were clustered into four major phyla: Pseudomonadota (previously known as Proteobacteria), Bacteroidota (previously known as Bacteroidetes), Actinomycetota (previously known as Actinobacteria), and Bacillota (previously known as Firmicutes). The linear discriminate analysis effect size analysis identified distinct microbial abundance patterns among the sample types; Pseudomonas species was abundant in Australian corneal isolates (P < 0.007), Enterobacteriales showed higher abundance in Indian corneal isolates (P < 0.017), and Bacteroidota was abundant in Australian water isolates (P < 0.019). The bacterial beta diversity of Acanthamoeba isolates from keratitis patients in India and Australia significantly differed (P < 0.05), while alpha diversity did not vary based on the country of origin or source of isolation (P > 0.05). More diverse intracellular bacteria were identified in water isolates as compared with clinical isolates. Confocal and electron microscopy confirmed the bacterial cells undergoing binary fission within the amoebal host, indicating the presence of viable bacteria. This study sheds light on the possibility of a sympatric lifestyle within Acanthamoeba, thereby emphasizing its crucial role as a bunker and carrier of potential human pathogens.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Hyderabad, 500034, India
| | - Ronnie Mooney
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, South-Eastern Sydney Local Health District, Sydney, NSW 2000, Australia
- Save Sight Institute, University of Sydney, Sydney, NSW 2000, Australia
| | - Paul R Badenoch
- College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia
| | - Samendra Sherchan
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, United States
| | - Fiona L Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
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Rayamajhee B, Willcox M, Henriquez FL, Vijay AK, Petsoglou C, Shrestha GS, Peguda HK, Carnt N. The role of naturally acquired intracellular Pseudomonas aeruginosa in the development of Acanthamoeba keratitis in an animal model. PLoS Negl Trop Dis 2024; 18:e0011878. [PMID: 38166139 PMCID: PMC10795995 DOI: 10.1371/journal.pntd.0011878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/18/2024] [Accepted: 12/21/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. METHODOLOGY/PRINCIPAL FINDINGS Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. CONCLUSIONS/SIGNIFICANCE Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Scotland, United Kingdom
| | - Ajay Kumar Vijay
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Mahdavi Poor B, Rashedi J, Asgharzadeh V, Mirmazhary A, Gheitarani N. Proteases of Acanthamoeba. Parasitol Res 2023; 123:19. [PMID: 38063887 DOI: 10.1007/s00436-023-08059-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/27/2023] [Indexed: 12/18/2023]
Abstract
The members of genus Acanthamoeba are the etiological agent of uncommon but severe or even fatal opportunistic infections in human beings. The presence of different classes of intracellular and extracellular proteases including serine proteases, cysteine proteases, and metalloproteases has been well documented in environmental and clinical isolates of Acanthamoeba spp. However, the role of the proteolytic enzymes in physiological, biological, and pathological mechanisms of the amoeba remains partially investigated. Some attempts have been conducted using various methods to determine the profile of proteases (number, class, optimal conditions, and activity of the enzymes), and possible pathogenicity mechanism of the proteolytic enzymes (various protein substrate degradation, cytopathic effect on different cell lines). In some cases, it was attempted to correlate intracellular and extracellular protease profile with pathogenicity potential of strains. This review revealed that the protease profile of different strains of Acanthamoeba was extremely complex, therefore, further comprehensive studies with application of a combination of various methods may help to elucidate the role of the enzymes.
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Affiliation(s)
- Behroz Mahdavi Poor
- Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Golgasht Ave, Azadi St, Tabriz, Iran.
| | - Jalil Rashedi
- Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Golgasht Ave, Azadi St, Tabriz, Iran
| | - Vahid Asgharzadeh
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amirali Mirmazhary
- Department of Laboratory Sciences, Faculty of Paramedicine, Tabriz University of Medical Sciences, Golgasht Ave, Azadi St, Tabriz, Iran
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Huang L, Suhler EB, Rosenberg C, Ta Kim D, Winthrop KL, Doan T, Lin P. Acanthamoeba-associated retinitis successfully treated with intravitreal and systemic antimicrobials. Am J Ophthalmol Case Rep 2023; 32:101902. [PMID: 37663996 PMCID: PMC10474359 DOI: 10.1016/j.ajoc.2023.101902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/03/2023] [Accepted: 07/19/2023] [Indexed: 09/05/2023] Open
Abstract
Purpose To describe a case of unilateral Acanthamoeba-associated retinitis in the absence of concomitant corneal infection in an immunocompetent host without risk factors. Observations A 37-year-old woman presented with unilateral multifocal retinitis with minimal vitritis. Anterior segment was normal. Conventional diagnostics of bacterial, fungal, viral, Toxoplasma and Toxocara etiologies all returned negative. Empiric treatments were unsuccessful, including oral valacyclovir, oral fluconazole, as well as intravitreal injection of vancomycin and ceftazidime. Metagenomic deep sequencing (MDS) identified Acanthamoeba genomic fragments in the vitreous sample. Multiple intravitreal voriconazole injections were performed and achieved partial suppression of lesion growth. Subsequent dual therapy of oral voriconazole and trimethoprim-sulfamethoxazole led to resolution of the lesions and vision improvement without further injections. Conclusions and importance This is an unusual case of unilateral Acanthamoeba-associated retinitis without concomitant corneal infection, diagnosed via unbiased DNA and RNA deep sequencing, with other etiologies ruled out by conventional approaches. Treatment with systemic and intravitreal therapy led to a successful resolution of retinitis and vision improvement. Our case demonstrates the potential of MDS as an unbiased diagnostic tool for rare ocular pathogens and the therapeutic effect of oral voriconazole with trimethoprim-sulfamethoxazole for Acanthamoeba intraocular infection.
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Affiliation(s)
- Lingling Huang
- Casey Eye Institute, Oregon Health & Science University, 515 SW Campus Drive, Portland, OR, USA
| | - Eric B. Suhler
- Casey Eye Institute, Oregon Health & Science University, 515 SW Campus Drive, Portland, OR, USA
- Veterans Affairs Portland Health Care System, 3710 Southwest US Veterans Hospital Road, Portland, OR, USA
| | - Christopher Rosenberg
- Casey Eye Institute, Oregon Health & Science University, 515 SW Campus Drive, Portland, OR, USA
| | - David Ta Kim
- University of British Columbia, 2550 Willow Street, Vancouver, British Columbia, Canada
| | - Kevin L. Winthrop
- Division of Infectious Diseases, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA
| | - Thuy Doan
- Francis I. Proctor Foundation, University of California San Francisco, 490 Illinois Street, San Francisco, CA, USA
| | - Phoebe Lin
- Casey Eye Institute, Oregon Health & Science University, 515 SW Campus Drive, Portland, OR, USA
- Cole Eye Institute, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH, USA
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11
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Kim MJ, Moon EK, Jo HJ, Quan FS, Kong HH. Phagocytosis-associated genes in Acanthamoeba castellanii feeding on Escherichia coli. PARASITES, HOSTS AND DISEASES 2023; 61:397-404. [PMID: 38043535 PMCID: PMC10693966 DOI: 10.3347/phd.23088] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/09/2023] [Indexed: 12/05/2023]
Abstract
Acanthamoeba species are free-living amoebae those are widely distributed in the environment. They feed on various microorganisms, including bacteria, fungi, and algae. Although majority of the microbes phagocytosed by Acanthamoeba spp. are digested, some pathogenic bacteria thrive within them. Here, we identified the roles of 3 phagocytosis-associated genes (ACA1_077100, ACA1_175060, and AFD36229.1) in A. castellanii. These 3 genes were upregulated after the ingestion of Escherichia coli. However, after the ingestion of Legionella pneumophila, the expression of these 3 genes was not altered after the consumption of L. pneumophila. Furthermore, A. castellanii transfected with small interfering RNS (siRNA) targeting the 3 phagocytosis-associated genes failed to digest phagocytized E. coli. Silencing of ACA1_077100 disabled phagosome formation in the E. coli-ingesting A. castellanii. Alternatively, silencing of ACA1_175060 enabled phagosome formation; however, phagolysosome formation was inhibited. Moreover, suppression of AFD36229.1 expression prevented E. coli digestion and consequently led to the rupturing of A. castellanii. Our results demonstrated that the ACA1_077100, ACA1_175060, and AFD36229.1 genes of Acanthamoeba played crucial roles not only in the formation of phagosome and phagolysosome but also in the digestion of E. coli.
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Affiliation(s)
- Min-Jeong Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447,
Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447,
Korea
| | - Hye-Jeong Jo
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447,
Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul 02447,
Korea
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, Core Research Institute, School of Medicine, Kyung Hee University, Seoul 02447,
Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan 49201,
Korea
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12
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Ledbetter EC, Capistrano da Silva E, Dong L, McDonough SP. Experimental Induction of Acute Acanthamoeba castellanii Keratitis in Cats. Transl Vis Sci Technol 2023; 12:10. [PMID: 37566398 PMCID: PMC10424800 DOI: 10.1167/tvst.12.8.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/09/2023] [Indexed: 08/12/2023] Open
Abstract
Purpose To develop a feline model of acute Acanthamoeba keratitis using methods that replicate natural routes of infection transmission. Methods Corneal Acanthamoeba castellanii inoculation was performed by three methods: topical inoculation with Acanthamoeba solution following corneal abrasion, placement of a contaminated contact lens for 7 days, and placement of a contaminated contact lens for 7 days following corneal abrasion. Sham inoculations with parasite-free medium and sterile contact lenses were also performed. Cats were monitored by ocular examination and in vivo corneal confocal microscopy for 21 days post-inoculation. Corneal samples were collected at intervals for microbiologic assessment, histopathology, and immunohistochemistry. Results All cats in the corneal abrasion groups developed clinical keratitis. Clinical ocular disease was inconsistently detected in cats from the contaminated contact lens only group. Initial corneal lesions were characterized by multifocal epithelial leukocyte infiltrates. Ocular lesions progressed to corneal epithelial ulceration and diffuse stromal inflammation. After 14 days, corneal ulcerations resolved, and stromal inflammation consolidated into multifocal subepithelial and stromal infiltrates. Corneal amoebae were detected by culture, in vivo confocal microscopy, histopathology, and immunohistochemistry in cats with keratitis. Neutrophilic and lymphocytic keratoconjunctivitis with lymphoplasmacytic anterior uveitis were identified by histopathology. Coinfection with aerobic bacteria was detected in some, but not all, cats with keratitis. Ocular disease was not detected in the sham inoculation groups. Conclusions Feline Acanthamoeba keratitis is experimentally transmissible by contaminated contact lenses and topical inoculation following corneal epithelial trauma. Translational Relevance Experimentally induced acute Acanthamoeba keratitis in cats is clinically and histopathologically similar to its human counterpart.
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Affiliation(s)
- Eric C. Ledbetter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | | | - Longying Dong
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Sean P. McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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13
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Rammohan R, Baidwal S, Venkatapathy N, Lorenzo-Morales J, Raghavan A. A 5-Year Review of Coinfections in Acanthamoeba keratitis From South India. Eye Contact Lens 2023; 49:334-338. [PMID: 37232397 DOI: 10.1097/icl.0000000000001005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2023] [Indexed: 05/27/2023]
Abstract
PURPOSE To ascertain the frequency of coinfections in Acanthamoeba keratitis, the nature of copathogens involved, and to analyze the implications in the context of current research on amoebic interactions. METHODS A retrospective case review from a Tertiary Care Eye Hospital in South India. Smear and culture data for coinfections in Acanthamoeba corneal ulcers were collected from records over a 5-year period. The significance and relevance of our findings in the light of current research on Acanthamoeba interactions were analyzed. RESULTS Eighty-five cases of culture-positive Acanthamoeba keratitis were identified over a 5-year period (43 of them being coinfections). Fusarium was most commonly identified species, followed by Aspergillus and the dematiaceous fungi. Pseudomonas spp was the commonest bacterial isolate. CONCLUSION Coinfections with Acanthamoeba are common at our centre, and account for 50% of Acanthamoeba keratitis. The diverse nature of the organisms involved in coinfections suggest that such amoebic interactions with other organisms are probably more widespread than recognized. To the best of our knowledge, this is the first documentation from a long-term study of pathogen diversity in Acanthamoeba coinfections. It is possible that Acanthamoeba itself may be virulence enhanced and secondary to the co-organism, breaching the ocular surface defenses in an already compromised cornea. However, observations from the existing literature on Acanthamoeba interactions with bacteria and certain fungi are based mainly on nonocular or nonclinical isolates. It would be illuminating if such studies are performed on Acanthamoeba and coinfectors from corneal ulcers-to ascertain whether interactions are endosymbiotic or virulence enhanced through amoebic passage.
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Affiliation(s)
- Ram Rammohan
- Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology (R.R., N.V., A.R.), Coimbatore; Fortis Hospital (S.B.), Chandigarh Road, Ludhiana, India; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSPC) (J.L.-M.), Universidad de La Laguna (ULL), La Laguna, Tenerife, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología (J.L.-M.), Universidad de La Laguna, Tenerife, Spain; and Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC) (J.L.-M.), Instituto de Salud Carlos III, Madrid, Spain
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14
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Huang JM, Sung KC, Lin WC, Lai HY, Wang YJ. Enhancement of capsular hypermucoviscosity in Klebsiella pneumoniae by Acanthamoeba. PLoS Negl Trop Dis 2023; 17:e0011541. [PMID: 37566587 PMCID: PMC10495012 DOI: 10.1371/journal.pntd.0011541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/11/2023] [Accepted: 07/18/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Acanthamoeba and Klebsiella pneumoniae are both environmental commensals. Recently, clinical harm caused by hypermucoviscous K. pneumoniae has been observed. However, the interaction between these microbes and the origin of hypermucoviscous K. pneumoniae have not been reported. METHODOLOGY/PRINCIPAL FINDINGS Here, we report that the bacterial capsule is enlarged when co-cultured with Acanthamoeba using India ink staining, and this effect depends on the number of parasites present. This interaction results in an enhancement of capsular polysaccharide production in the subsequent generations of K. pneumoniae, even without co-culturing with Acanthamoeba. The hypermucoviscosity of the capsule was examined using the sedimentation assay and string test. We also screened other K. pneumoniae serotypes, including K1, K2, K5, and K20, for interaction with Acanthamoeba using India ink staining, and found the same interaction effect. CONCLUSIONS/SIGNIFICANCE These findings suggest that the interaction between Acanthamoeba and K. pneumoniae could lead to harmful consequences in public health and nosocomial disease control, particularly hypermucoviscous K. pneumoniae infections.
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Affiliation(s)
- Jian-Ming Huang
- School of Medicine, National Tsing Hua University, Hsinchu, Taiwan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ko-Chiang Sung
- Department of Clinical Laboratory, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Wei-Chen Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hong-Yue Lai
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Jen Wang
- Department of Parasitology, School of Medicine, China Medical University, Taichung, Taiwan
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Marinho BTS, Santos DLD, Santos DLD, Rott MB. First report of free-living amoebae in watercourses in southern Brazil: molecular diagnosis and phylogenetic analysis of Vermamoeba vermiformis, Naegleria gruberi, and Acanthamoeba spp. JOURNAL OF WATER AND HEALTH 2023; 21:972-980. [PMID: 37515566 PMCID: wh_2023_126 DOI: 10.2166/wh.2023.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/31/2023]
Abstract
Free-living amoebae (FLA) are protozoa dispersed in different environments and are responsible for different infections caused to humans and other animals. Microorganisms such as Acanthamoeba spp., Vermamoeba sp., and Naegleria sp. are associated with diseases that affect the central nervous system, in addition to skin infections and keratitis, as occurs in the genus Acanthamoeba and with Vermamoeba vermiformis. Due to the concerns of these FLA in anthropogenic aquatic environments, this work aimed to identify these microorganisms present in waters of Porto Alegre, Brazil. One litre sample was collected in two watercourses during the summer of 2022 and inoculated onto non-nutrient agar plates containing heat-inactivated Escherichia coli. Polymerase chain reaction results indicated the presence of FLA of the genera Acanthamoeba, Vermamoeba, and Naegleria in the study areas. Genetic sequencing indicated the presence of V. vermiformis and Naegleria gruberi. These aquatic and anthropogenic environments can serve as a means of spread and contamination by FLA, which gives valuable information on public health in the city.
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Affiliation(s)
- Brenda Teixeira Scardini Marinho
- Protozoology Laboratory, Microbiology Immunology and Parasitology Department, Basic Health Sciences Institute, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, N 2600, Porto Alegre, Rio Grande do Sul 90035-002, Brazil E-mail:
| | - Denise Leal Dos Santos
- Protozoology Laboratory, Microbiology Immunology and Parasitology Department, Basic Health Sciences Institute, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, N 2600, Porto Alegre, Rio Grande do Sul 90035-002, Brazil
| | - Daniel Leal Dos Santos
- Faculty of Geography, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Avenue, N 6681, Porto Alegre, Rio Grande do Sul 90619-900, Brazil
| | - Marilise Brittes Rott
- Protozoology Laboratory, Microbiology Immunology and Parasitology Department, Basic Health Sciences Institute, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, N 2600, Porto Alegre, Rio Grande do Sul 90035-002, Brazil
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Kim MJ, Moon EK, Jo HJ, Quan FS, Kong HH. Identifying the function of genes involved in excreted vesicle formation in Acanthamoeba castellanii containing Legionella pneumophila. Parasit Vectors 2023; 16:215. [PMID: 37380986 DOI: 10.1186/s13071-023-05824-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/28/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Legionella spp. can survive and replicate inside host cells such as protozoa and macrophages. After enough growth, Legionella is released from the host cells as free legionellae or Legionella-filled vesicles. The vesicles support Legionella to survive for a long time in the environment and transmit to a new host. In this study, we identified the differentially expressed genes of Acanthamoeba infected by Legionella (ACA1_114460, ACA1_091500, and ACA1_362260) and examined their roles in the formation of the excreted vesicles and escape of Legionella from the Acanthamoeba. METHODS After ingestion of Escherichia coli and Legionella pneumophila, expression levels of target genes in Acanthamoeba were measured by real-time polymerase chain reaction (PCR) analysis. The roles of target genes were investigated by transfection of small interfering RNA (siRNA). The formation of Legionella-containing excreted vesicles and the vesicular co-localization with the lysosomes were examined by Giemsa stain and LysoTracker stain. RESULTS ACA1_114460, ACA1_091500, and ACA1_362260 were upregulated after ingestion of Legionella in Acanthamoeba. ACA1_114460- and ACA1_091500-silenced Acanthamoeba failed to form the Legionella-containing excreted vesicles. Legionella was released as free legionellae from the Acanthamoeba. When the ACA1_362260 of Acanthamoeba was silenced, Legionella-containing excreted vesicles were fused with the lysosome. CONCLUSIONS These results indicated that ACA1_114460, ACA1_091500, and ACA1_362260 of Acanthamoeba played important roles in the formation of Legionella-containing excreted vesicles and inhibition of the lysosomal co-localization with the phagosome.
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Affiliation(s)
- Min-Jeong Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Hye-Jeong Jo
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate school, Kyung Hee University, Seoul, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan, Republic of Korea.
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Novel Anti-Acanthamoebic Activities of Irosustat and STX140 and Their Nanoformulations. Antibiotics (Basel) 2023; 12:antibiotics12030561. [PMID: 36978428 PMCID: PMC10044433 DOI: 10.3390/antibiotics12030561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
Pathogenic Acanthamoeba produce keratitis and fatal granulomatous amoebic encephalitis. Treatment remains problematic and often ineffective, suggesting the need for the discovery of novel compounds. For the first time, here we evaluated the effects of the anticancer drugs Irosustat and STX140 alone, as well as their nanoformulations, against A. castellanii via amoebicidal, excystment, cytopathogenicity, and cytotoxicity assays. Nanoformulations of the compounds were successfully synthesized with high encapsulation efficiency of 94% and 82% for Irosustat and STX140, respectively. Nanoparticles formed were spherical in shape and had a unimodal narrow particle size distribution, mean of 145 and 244 nm with a polydispersity index of 0.3, and surface charge of −14 and −15 mV, respectively. Irosustat and STX140 exhibited a biphasic release profile with almost 100% drug released after 48 h. Notably, Irosustat significantly inhibited A. castellanii viability and amoebae-mediated cytopathogenicity and inhibited the phenotypic transformation of amoebae cysts into the trophozoite form, however their nanoformulations depicted limited effects against amoebae but exhibited minimal cytotoxicity when tested against human cells using lactate dehydrogenase release assays. Accordingly, both compounds have potential for further studies, with the hope of discovering novel anti-Acanthamoeba compounds, and potentially developing targeted therapy against infections of the central nervous system.
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18
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Fernández-Vecilla D, López-Plandolit Antolín S, Unzaga-Barañano MJ, Díaz de Tuesta-Del Arco JL. Streptococcus oralis, an opportunistic pathogen in crystalline keratopathy. ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA (ENGLISH ED.) 2023; 41:196-198. [PMID: 36283959 DOI: 10.1016/j.eimce.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 04/29/2022] [Accepted: 05/02/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Domingo Fernández-Vecilla
- Clinical Microbiology and Parasitology Service, Basurto University Hospital, Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Spain.
| | - Silvia López-Plandolit Antolín
- Ophthalmology Service, Basurto University Hospital, Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Miren Josebe Unzaga-Barañano
- Clinical Microbiology and Parasitology Service, Basurto University Hospital, Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - José Luis Díaz de Tuesta-Del Arco
- Clinical Microbiology and Parasitology Service, Basurto University Hospital, Bilbao, Spain; Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
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19
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Rayamajhee B, Sharma S, Willcox M, Henriquez FL, Rajagopal RN, Shrestha GS, Subedi D, Bagga B, Carnt N. Assessment of genotypes, endosymbionts and clinical characteristics of Acanthamoeba recovered from ocular infection. BMC Infect Dis 2022; 22:757. [PMID: 36175838 PMCID: PMC9520893 DOI: 10.1186/s12879-022-07741-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Introduction Acanthamoeba is an emerging pathogen, infamous for its resilience against antiprotozoal compounds, disinfectants and harsh environments. It is known to cause keratitis, a sight-threatening, painful and difficult to treat corneal infection which is often reported among contact lens wearers and patients with ocular trauma. Acanthamoeba comprises over 24 species and currently 23 genotypes (T1-T23) have been identified. Aims This retrospective study was designed to examine the Acanthamoeba species and genotypes recovered from patients with Acanthamoeba keratitis (AK), determine the presence of endosymbionts in ocular isolates of Acanthamoeba and review the clinical presentations. Methodology Thirteen culture-confirmed AK patients treated in a tertiary eye care facility in Hyderabad, India from February to October 2020 were included in this study. The clinical manifestations, medications and visual outcomes of all patients were obtained from medical records. The Acanthamoeba isolates were identified by sequencing the ribosomal nuclear subunit (rns) gene. Acanthamoeba isolates were assessed for the presence of bacterial or fungal endosymbionts using molecular assays, PCR and fluorescence in situ hybridization (FISH). Results The mean age of the patients was 33 years (SD ± 17.4; 95% CI 22.5 to 43.5 years). Six (46.2%) cases had AK associated risk factors; four patients had ocular trauma and two were contact lens wearers. A. culbertsoni (6/13, 46.2%) was the most common species, followed by A. polyphaga and A. triangularis. Most of the isolates (12/13) belonged to genotype T4 and one was a T12; three sub-clusters T4A, T4B, and T4F were identified within the T4 genotype. There was no significant association between Acanthamoeba types and clinical outcomes. Eight (61.5%) isolates harboured intracellular bacteria and one contained Malassezia restricta. The presence of intracellular microbes was associated with a higher proportion of stromal infiltrates (88.9%, 8/9), epithelial defect (55.6%, 5/9) and hypopyon (55.6%, 5/9) compared to 50% (2/4), 25% (1/4) and 25% (1/4) AK cases without intracellular microbes, respectively. Conclusions Genotype T4 was the predominant isolate in southern India. This is the second report of T12 genotype identified from AK patient in India, which is rarely reported worldwide. The majority of the Acanthamoeba clinical isolates in this study harboured intracellular microbes, which may impact clinical characteristics of AK. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07741-4.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Kallam Anji Reddy Campus, Hyderabad, India
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley, PA1 2BE, Scotland, UK
| | | | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Bhupesh Bagga
- The Cornea Institute, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Karsenti N, Purssell A, Lau R, Ralevski F, Bhasker S, Raheel H, Boggild AK. Surveillance of Amoebic Keratitis-Causing Acanthamoebae for Potential Bacterial Endosymbionts in Ontario, Canada. Pathogens 2022; 11:pathogens11060661. [PMID: 35745515 PMCID: PMC9230791 DOI: 10.3390/pathogens11060661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/02/2022] [Accepted: 06/07/2022] [Indexed: 02/04/2023] Open
Abstract
Acanthamoeba spp. are the causative pathogens of several infections, including amoebic keratitis (AK), a vision-threatening infection. Acanthamoebae from corneal specimens of patients with AK harbor bacterial endosymbionts, which may increase virulence. We sought to understand the spectrum of bacterial endosymbionts present in clinical isolates of Acanthamoeba spp. identified in our reference parasitology laboratory. Isolates of Acanthamoeba spp. obtained from our biobank of anonymized corneal scrapings were screened for potential endosymbionts by PCR using primer pairs detecting bacteria belonging to orders Chlamydiales, Rickettsiales, or Legionellales and pan16S primers. Three primer pairs specific to the 18s rRNA gene of Acanthamoeba spp. were used for the amplification of Acanthamoeba DNA used for sequencing. Sanger sequencing of all PCR products was performed, followed by BLAST analysis for species identification. We screened 26 clinical isolates of Acanthamoeba spp. for potential endosymbionts. Five isolates (19%) were found to contain bacterial DNA belonging to Legionellales. Three (11%) contained members of the Rickettsiales and Pseudomonas genticulata was detected in a Rickettsia-positive sample. One strain (4%) contained Neochlamydia hartmannellae, a member of the Chlamydiales order. Bacterial endosymbionts are prevalent in clinical strains of Acanthamoeba causing AK isolated from corneal scrapings. The demonstration of these organisms in clinical Acanthamoeba isolates supports a potential exploration of anti-endosymbiont therapeutics as an adjuvant therapy in the treatment of AK.
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Affiliation(s)
- Nessika Karsenti
- Schulich School of Medicine & Dentistry, London, ON N6A 5C1, Canada; (N.K.); (H.R.)
| | - Andrew Purssell
- Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Rachel Lau
- Public Health Ontario Laboratories, Public Health Ontario, Toronto, ON M5G 1M1, Canada; (R.L.); (F.R.)
| | - Filip Ralevski
- Public Health Ontario Laboratories, Public Health Ontario, Toronto, ON M5G 1M1, Canada; (R.L.); (F.R.)
| | - Shveta Bhasker
- Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5S 1A1, Canada;
| | - Hira Raheel
- Schulich School of Medicine & Dentistry, London, ON N6A 5C1, Canada; (N.K.); (H.R.)
| | - Andrea K. Boggild
- Tropical Disease Unit, Division of Infectious Diseases, UHN-Toronto General Hospital, Toronto, ON M5G 2C4, Canada
- Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A1, Canada
- Correspondence: ; Tel.: +1-416-340-3675
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21
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Fernández-Vecilla D, López-Plandolit Antolín S, Unzaga-Barañano MJ, Díaz de Tuesta-del Arco JL. Streptococcus oralis, un patógeno oportunista en la queratopatía cristalina. Enferm Infecc Microbiol Clin 2022. [DOI: 10.1016/j.eimc.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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22
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Reyes-Batlle M, Sifaoui I, Rodríguez-Expósito RL, Piñero JE, Lorenzo-Morales J. New Insights in Acanthamoeba. Pathogens 2022; 11:pathogens11050609. [PMID: 35631129 PMCID: PMC9146694 DOI: 10.3390/pathogens11050609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/16/2022] [Indexed: 01/25/2023] Open
Affiliation(s)
- María Reyes-Batlle
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna (ULL), 38206 Tenerife, Spain; (I.S.); (R.L.R.-E.); (J.E.P.); (J.L.-M.)
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad De La Laguna, La Laguna, 38203 Tenerife, Islas Canarias, Spain
- Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), 28029 Madrid, Spain
- Correspondence:
| | - Ines Sifaoui
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna (ULL), 38206 Tenerife, Spain; (I.S.); (R.L.R.-E.); (J.E.P.); (J.L.-M.)
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad De La Laguna, La Laguna, 38203 Tenerife, Islas Canarias, Spain
- Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), 28029 Madrid, Spain
| | - Rubén L. Rodríguez-Expósito
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna (ULL), 38206 Tenerife, Spain; (I.S.); (R.L.R.-E.); (J.E.P.); (J.L.-M.)
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad De La Laguna, La Laguna, 38203 Tenerife, Islas Canarias, Spain
- Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), 28029 Madrid, Spain
| | - José E. Piñero
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna (ULL), 38206 Tenerife, Spain; (I.S.); (R.L.R.-E.); (J.E.P.); (J.L.-M.)
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad De La Laguna, La Laguna, 38203 Tenerife, Islas Canarias, Spain
- Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), 28029 Madrid, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jacob Lorenzo-Morales
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna (ULL), 38206 Tenerife, Spain; (I.S.); (R.L.R.-E.); (J.E.P.); (J.L.-M.)
- Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Universidad De La Laguna, La Laguna, 38203 Tenerife, Islas Canarias, Spain
- Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), 28029 Madrid, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
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A Comparative Genomic Approach to Determine the Virulence Factors and Horizontal Gene Transfer Events of Clinical Acanthamoeba Isolates. Microbiol Spectr 2022; 10:e0002522. [PMID: 35416714 PMCID: PMC9045148 DOI: 10.1128/spectrum.00025-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acanthamoeba species are among the most ubiquitous protists that are widespread in soil and water and act as both a replicative niche and vectors for dispersal. They are the most important human intracellular pathogens, causing Acanthamoeba keratitis (AK) and severely damaging the human cornea. The sympatric lifestyle within the host and amoeba-resisting microorganisms (ARMs) promotes horizontal gene transfer (HGT). However, the genomic diversity of only A. castellanii and A. polyphaga has been widely studied, and the pathogenic mechanisms remain unknown. Thus, we examined 7 clinically pathogenic strains by comparative genomic, phylogenetic, and rhizome gene mosaicism analyses to explore amoeba-symbiont interactions that possibly contribute to pathogenesis. Genetic characterization and phylogenetic analysis showed differences in functional characteristics between the "open" state of T3 and T4 isolates, which may contribute to the differences in virulence and pathogenicity. Through comparative genomic analysis, we identified potential genes related to virulence, such as metalloprotease, laminin-binding protein, and HSP, that were specific to the genus Acanthamoeba. Then, analysis of putative sequence trafficking between Acanthamoeba and Pandoraviruses or Acanthamoeba castellanii medusaviruses provided the best hits with viral genes; among bacteria, Pseudomonas had the most significant numbers. The most parsimonious evolutionary scenarios were between Acanthamoeba and endosymbionts; nevertheless, in most cases, the scenarios are more complex. In addition, the differences in exchanged genes were limited to the same family. In brief, this study provided extensive data to suggest the existence of HGT between Acanthamoeba and ARMs, explaining the occurrence of diseases and challenging Darwin's concept of eukaryotic evolution. IMPORTANCE Acanthamoeba has the ability to cause serious blinding keratitis. Although the prevalence of this phenomenon has increased in recent years, our knowledge of the underlying opportunistic pathogenic mechanism maybe remains incomplete. In this study, we highlighted the importance of Pseudomonas in the pathogenesis pathway using comprehensive a whole genomics approach of clinical isolates. The horizontal gene transfer events help to explain how endosymbionts contribute Acanthamoeba to act as an opportunistic pathogen. Our study opens up several potential avenues for future research on the differences in pathogenicity and interactions among clinical strains.
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Kaufman AR, Tu EY. Advances in the management of Acanthamoeba keratitis: A review of the literature and synthesized algorithmic approach. Ocul Surf 2022; 25:26-36. [DOI: 10.1016/j.jtos.2022.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 01/01/2023]
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Dos Santos DL, Virginio VG, Berté FK, Lorenzatto KR, Marinho DR, Kwitko S, Locatelli CI, Freitas EC, Rott MB. Clinical and molecular diagnosis of Acanthamoeba keratitis in contact lens wearers in southern Brazil reveals the presence of an endosymbiont. Parasitol Res 2022; 121:1447-1454. [PMID: 35194678 DOI: 10.1007/s00436-022-07474-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/17/2022] [Indexed: 12/17/2022]
Abstract
Acanthamoeba keratitis (AK) is an infection that is mostly observed in contact lens wearers. It is often misdiagnosed causing delays in the administration of the correct treatment. The aim of this study was to report the outcome of clinical and molecular diagnosis of AK cases during the summer of 2019 in the southern region of Brazil. Three suspected cases of AK were discovered after an ophthalmic examination at a public hospital in the city of Porto Alegre. These cases were then confirmed through laboratory diagnosis (cell culture and molecular analysis by PCR and sequencing). In each of the three clinical sample cell cultures of corneal scraping and molecular analysis confirmed the presence of Acanthamoeba spp., all belonging to the morphological group II and to the genotype T4, which is the most common genotype associated with AK. In addition, Acanthamoeba spp. isolated from one of the clinical samples was found to harbor the Candidatus Paracaedibacter acanthamoeba, a bacterial endosymbiont. The presence of Ca. Paracaedibacter acanthamoeba in clinical isolates requires further research to reveal its possible role in the pathogenicity of Acanthamoeba infections.
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Affiliation(s)
- Denise Leal Dos Santos
- Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
| | - Veridiana Gomes Virginio
- Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
| | - Francisco Kercher Berté
- Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
| | - Karina Rodrigues Lorenzatto
- Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
| | - Diane Ruschel Marinho
- Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
| | - Sergio Kwitko
- Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
| | - Claudete Inês Locatelli
- Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
| | - Eduarda Correa Freitas
- Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
| | - Marilise Brittes Rott
- Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil.
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Tanzifi A, Moghaddam Y, Dodangeh S, Daryani A, Sarvi S, Gholami S, Hosseini SA, Chegeni TN, Hosseininejad Z. Detection and Molecular Characterization of Potentially Pathogenic Free-Living Amoebae from Recreational and Public Soils in Mazandaran, Northern Iran. IRANIAN JOURNAL OF PARASITOLOGY 2021; 16:295-304. [PMID: 34557245 PMCID: PMC8418651 DOI: 10.18502/ijpa.v16i2.6316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/19/2020] [Indexed: 11/24/2022]
Abstract
Background: Free-living amoeba (FLA) belonging to Acanthamoeba spp., Naegleria, and Balamuthia mandrillaris are the soil-born protozoa. This study aimed to survey the occurrence of FLA, including Acanthamoeba spp., B. mandrillaris, Vermamoeba spp., and Naegleria spp., in soil samples collected from various districts of Mazandaran Province (Northern Iran) from July to December 2018. Methods: Overall, 118 soil samples from the recreational and public places were surveyed for the existence of Acanthamoeba spp., Vermamoeba, Naegleria, and B. mandrillaris using both morphological key and molecular tools with genus-specific primers of JDP1, NA, ITS1, and Bal, respectively. To verify the taxonomic status of isolated amoeba, the phylogenetic tree was made based on sequences of 18S rRNA by MEGA (5.05) software with the maximum likelihood model. Results: Overall, 61/118 samples (51.6%) were contaminated with FLA, and based on the sequencing data, 29 isolates were successfully sequenced. Among the samples, all isolated Acanthamoeba (52.4%) belonged to the T4 genotype with amplification of the DF3 region (18S rRNA gene). Internal transcribed spacer (ITS) sequencing revealed the presence of one strain of Naegleria americana. Twenty-eight V. vermiformis were also confirmed based on Nuclear SSU rDNA. Morphological survey and PCR assay did not show any positive samples for B. mandrillaris. Conclusion: The present study indicates the occurrence of FLA in soil sources of the recreational and public places in Mazandaran province that it can be a severe risk to human health. Thus, more studies are expected to survey the infection source in patients with FLA-related diseases.
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Affiliation(s)
- Asal Tanzifi
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Yousef Moghaddam
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Samira Dodangeh
- Department of Medical Parasitology and Mycology, Medical Microbiology Research Center, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Ahmad Daryani
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shirzad Gholami
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | - Seyed Abdollah Hosseini
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran
| | | | - Zahra Hosseininejad
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
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Kořený L, Oborník M, Horáková E, Waller RF, Lukeš J. The convoluted history of haem biosynthesis. Biol Rev Camb Philos Soc 2021; 97:141-162. [PMID: 34472688 DOI: 10.1111/brv.12794] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 01/14/2023]
Abstract
The capacity of haem to transfer electrons, bind diatomic gases, and catalyse various biochemical reactions makes it one of the essential biomolecules on Earth and one that was likely used by the earliest forms of cellular life. Since the description of haem biosynthesis, our understanding of this multi-step pathway has been almost exclusively derived from a handful of model organisms from narrow taxonomic contexts. Recent advances in genome sequencing and functional studies of diverse and previously neglected groups have led to discoveries of alternative routes of haem biosynthesis that deviate from the 'classical' pathway. In this review, we take an evolutionarily broad approach to illuminate the remarkable diversity and adaptability of haem synthesis, from prokaryotes to eukaryotes, showing the range of strategies that organisms employ to obtain and utilise haem. In particular, the complex evolutionary histories of eukaryotes that involve multiple endosymbioses and horizontal gene transfers are reflected in the mosaic origin of numerous metabolic pathways with haem biosynthesis being a striking case. We show how different evolutionary trajectories and distinct life strategies resulted in pronounced tensions and differences in the spatial organisation of the haem biosynthesis pathway, in some cases leading to a complete loss of a haem-synthesis capacity and, rarely, even loss of a requirement for haem altogether.
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Affiliation(s)
- Luděk Kořený
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge, CB2 1QW, U.K
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, České Budějovice (Budweis), 370 05, Czech Republic.,Faculty of Sciences, University of South Bohemia, Branišovská, České Budějovice (Budweis), 31, Czech Republic
| | - Eva Horáková
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, České Budějovice (Budweis), 370 05, Czech Republic
| | - Ross F Waller
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge, CB2 1QW, U.K
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovská 31, České Budějovice (Budweis), 370 05, Czech Republic.,Faculty of Sciences, University of South Bohemia, Branišovská, České Budějovice (Budweis), 31, Czech Republic
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First Evidence for Colonizing of Acanthamoeba T4 Genotype in Urinary Tracts of Patients with Recurrent Urinary Tract Infections. Acta Parasitol 2021; 66:932-937. [PMID: 33713274 DOI: 10.1007/s11686-021-00358-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/19/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Limited evidence about the presence of Acanthamoeba spp. in urine specimens collected from urinary catheters of the patients in the intensive care units persuaded our study. No evidence has been found about colonizing of Acanthamoeba spp., in urinary tracts of patients with recurrent urinary tract infections (UTIs) yet. METHODS In this study, 50 urine samples were collected from patients presenting with recurrent UTI. The type of bacteria causing UTI was determined by using bacteriological tests. To cultivate Acanthamoeba spp., in a sterile condition, 10 mL of urine was centrifuged and the sediment was cultivated on non-nutrient agar. Genotypes were determined by sequencing the DF3 region of the 18S rRNA gene. RESULTS The bacteriological test findings on the urine samples of the UTI patients (n = 30) demonstrated that those were found to be positive for Escherichia coli (n = 17), Staphylococcus aureus (n = 6), Pseudomonas aeruginosa (n = 4) and Klebsiella spp. (n = 3) respectively. Moreover, a total of 50 urine samples was examined; 6 (6/50; 12%) and 11 (11/50; 22%) were positive by using culture and the PCR test for Acanthamoeba spp., respectively. Sequencing analysis showed all isolates were T4 genotype. CONCLUSIONS Our data showed that the high relative prevalence of Acanthamoeba T4 genotype spp., in the urine of recurrent UTI patients. As well as, providing the first evidence for colonizing of the Acanthamoeba in the urinary tracts of patients with recurrent UTIs. These findings, warrant further investigation among those patients to fully appraise the role of Acanthamoeba spp., as possible latent carriers for resistant bacteria and biofilm formation in the future.
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Thomas CN, Bernardo-Colón A, Courtie E, Essex G, Rex TS, Blanch RJ, Ahmed Z. Effects of intravitreal injection of siRNA against caspase-2 on retinal and optic nerve degeneration in air blast induced ocular trauma. Sci Rep 2021; 11:16839. [PMID: 34413361 PMCID: PMC8377143 DOI: 10.1038/s41598-021-96107-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/05/2021] [Indexed: 11/11/2022] Open
Abstract
Ocular repeated air blast injuries occur from low overpressure blast wave exposure, which are often repeated and in quick succession. We have shown that caspase-2 caused the death of retinal ganglion cells (RGC) after blunt ocular trauma. Here, we investigated if caspase-2 also mediates RGC apoptosis in a mouse model of air blast induced indirect traumatic optic neuropathy (b-ITON). C57BL/6 mice were exposed to repeated blasts of overpressure air (3 × 2 × 15 psi) and intravitreal injections of siRNA against caspase-2 (siCASP2) or against a control enhanced green fluorescent protein (siEGFP) at either 5 h after the first 2 × 15 psi ("post-blast") or 48 h before the first blast exposure ("pre-blast") and repeated every 7 days. RGC counts were unaffected by the b-ITON or intravitreal injections, despite increased degenerating ON axons, even in siCASP2 "post-blast" injection groups. Degenerating ON axons remained at sham levels after b-ITON and intravitreal siCASP2 "pre-blast" injections, but with less degenerating axons in siCASP2 compared to siEGFP-treated eyes. Intravitreal injections "post-blast" caused greater vitreous inflammation, potentiated by siCASP2, with less in "pre-blast" injected eyes, which was abrogated by siCASP2. We conclude that intravitreal injection timing after ocular trauma induced variable retinal and ON pathology, undermining our candidate neuroprotective therapy, siCASP2.
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Affiliation(s)
- Chloe N Thomas
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | | | - Ella Courtie
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Gareth Essex
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Tonia S Rex
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Richard J Blanch
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, UK.
- Centre for Trauma Sciences Research, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Trauma Sciences Research, University of Birmingham, Birmingham, B15 2TT, UK.
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Fabros MRL, Diesta XRS, Oronan JA, Verdejo KS, Garcia JASM, Sophia Romey M, Milanez GDJ. Current report on the prevalence of free-living amoebae (FLA) in natural hot springs: a systematic review. JOURNAL OF WATER AND HEALTH 2021; 19:563-574. [PMID: 34371494 DOI: 10.2166/wh.2021.101] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The occurrence of potentially pathogenic free-living amoebae (FLA) in natural hot springs is considered a public health concern. FLAs are known to cause serious health outcomes to a wide spectrum of mammalian hosts. The present study aimed to provide the distribution of isolated cases of FLAs in hot springs through a systematic review process of available published articles online. Relevant studies are published between January 2010 and January 2020 involving the isolation of Naegleria spp., Acanthamoeba spp., Balamuthia spp., Sappinia spp., and Vermamoeba spp. in natural hot springs in the United States, South America, North America, Europe, Asia, and Africa. Articles were identified through a search of PubMed and Google Scholar databases. Out of 94 articles screened, a total of 20 articles are included in the study with consideration of established inclusion and exclusion criteria. The most common FLAs isolated in hot springs are Acanthamoeba spp. (134; 48.5%) and Naegleria spp. (127; 46.0%). Other FLAs isolated in hot springs include Balamuthia spp. (2; 0.7%) and Vermamoeba spp. (13; 4.7%). FLA in hot springs used for recreational and medical purposes is a potential source of infection. It is recommended that strict surveillance and maintenance of hot springs be implemented to prevent potential future infection.
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Affiliation(s)
| | | | - John Anthony Oronan
- Department of Medical Technology, Far Eastern University, Manila 1015, Philippines E-mail:
| | - Kim Sofia Verdejo
- Department of Medical Technology, Far Eastern University, Manila 1015, Philippines E-mail:
| | | | - Ma Sophia Romey
- Department of Medical Technology, Far Eastern University, Manila 1015, Philippines E-mail:
| | - Giovanni De Jesus Milanez
- Department of Medical Technology, Far Eastern University, Manila 1015, Philippines E-mail: ; Division III (Medical Sciences), National Research Council of the Philippines, Manila, Philippines
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Acanthamoeba Keratitis Versus Mixed Acanthamoeba and Bacterial Keratitis: Comparison of Clinical and Microbiological Profiles. Cornea 2021; 39:1112-1116. [PMID: 32452992 DOI: 10.1097/ico.0000000000002337] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the clinical profiles and outcomes of patients with Acanthamoeba keratitis with or without mixed bacterial infection. METHODS A retrospective analysis of microbiologically confirmed AK cases presenting to a tertiary care center over a 9-year period was conducted. Fourteen eyes in the coinfected group (group 1) and 24 eyes in the AK group (group 2) were analyzed to study the differences in these 2 groups of patients. The cases were diagnosed using a conventional microscopic analysis with staining techniques confirmed by cultural methods and were treated, which tailored to the microbiology report. RESULTS There was no difference in the demographic profile and presenting features in the 2 groups. Duration of symptoms and history of ocular trauma, contact lens wear, and previous steroid usage were also similar for both the groups. Dense central corneal infiltrate was the common presentation for both groups (7/14 vs. 16/24 in group 1 vs. group 2). Epithelial defect without dense stromal infiltrate was significantly more common in group 1 (42.9% vs. 4.2%, P = 0.003) as a presenting clinical feature. Hypopyon was present in 8/14 of group 1 versus 9/24 of group 2 eyes (P = 0.25). No significant difference was found in the final visual acuity in pure and mixed AK cases, and the need for surgical intervention was comparable. The most common bacterial pathogen isolated in the mixed group was the Staphylococcus species. CONCLUSIONS Bacterial coinfection is common in patients with Acanthamoeba keratitis. Coinfection did not point toward a worse clinical disease at presentation or outcome.
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Wang YJ, Li SC, Lin WC, Huang FC. Intracellular Microbiome Profiling of the Acanthamoeba Clinical Isolates from Lens Associated Keratitis. Pathogens 2021; 10:pathogens10030266. [PMID: 33669045 PMCID: PMC7996525 DOI: 10.3390/pathogens10030266] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 11/16/2022] Open
Abstract
Acanthamoeba act as hosts for various microorganisms and pathogens, causing Acanthamoeba Keratitis (AK). To investigate the association between endosymbionts and AK progression, we performed a metagenomics study to characterize the intracellular microbiome from five lenses associated with AK isolates and standard strains to characterize the role of ocular flora in AK progression. The used clinical isolates were axenic cultured from lenses associated with AK patients. AK isolates and standard controls such as 16S ribosomal RNA sequencing techniques were used for analysis. The microbiome compositions and relative abundance values were compared. The orders of Clostridiales and Bacteroidales presented major populations of intracellular microbes belonging to all isolates. Comparison of the different source isolates showed that most of the abundance in keratitis isolates came from Ruminococcus gnavus (121.0 folds), Eubacterium dolichum (54.15 folds), Roseburia faecis (24.51 folds), and Blautia producta (3.15 folds). Further analysis of the relative abundance data from keratitis isolates showed that Blautia producta was positively correlated with the disease course. In contrast, Bacteroides ovatus was found to be abundant in early-stage keratitis isolates. This study reveals the abundant anaerobic Gram-positive rods present in severe keratitis isolate and characterize the association between Acanthamoeba and ocular flora in AK progression.
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Affiliation(s)
- Yu-Jen Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
| | - Sung-Chou Li
- Genomics and Proteomics Core Laboratory, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83325, Taiwan;
| | - Wei-Chen Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
- Correspondence: (W.-C.L.); (F.-C.H.); Tel.: +886-6-2353535 (ext. 5584) (W.-C.L.); +886-2353535 (ext. 5441) (F.-C.H.)
| | - Fu-Chin Huang
- Department of Ophthalmology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan
- Correspondence: (W.-C.L.); (F.-C.H.); Tel.: +886-6-2353535 (ext. 5584) (W.-C.L.); +886-2353535 (ext. 5441) (F.-C.H.)
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Rayamajhee B, Subedi D, Peguda HK, Willcox MD, Henriquez FL, Carnt N. A Systematic Review of Intracellular Microorganisms within Acanthamoeba to Understand Potential Impact for Infection. Pathogens 2021; 10:pathogens10020225. [PMID: 33670718 PMCID: PMC7922382 DOI: 10.3390/pathogens10020225] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
Acanthamoeba, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. Acanthamoeba feeds different microorganisms, including potentially pathogenic prokaryotes; some of microbes have developed ways of surviving intracellularly and this may mean that Acanthamoeba acts as incubator of important pathogens. A systematic review of the literature was performed in order to capture a comprehensive picture of the variety of microbial species identified within Acanthamoeba following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Forty-three studies met the inclusion criteria, 26 studies (60.5%) examined environmental samples, eight (18.6%) studies examined clinical specimens, and another nine (20.9%) studies analysed both types of samples. Polymerase chain reaction (PCR) followed by gene sequencing was the most common technique used to identify the intracellular microorganisms. Important pathogenic bacteria, such as E. coli, Mycobacterium spp. and P. aeruginosa, were observed in clinical isolates of Acanthamoeba, whereas Legionella, adenovirus, mimivirus, and unidentified bacteria (Candidatus) were often identified in environmental Acanthamoeba. Increasing resistance of Acanthamoeba associated intracellular pathogens to antimicrobials is an increased risk to public health. Molecular-based future studies are needed in order to assess the microbiome residing in Acanthamoeba, as a research on the hypotheses that intracellular microbes can affect the pathogenicity of Acanthamoeba infections.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
- Department of Infection and Immunology, Kathmandu Research Institute for Biological Sciences (KRIBS), Lalitpur 44700, Nepal
- Correspondence: or
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia;
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - Mark Duncan Willcox
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - Fiona L. Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley PA1 2BE, UK;
| | - Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
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Henriquez FL, Mooney R, Bandel T, Giammarini E, Zeroual M, Fiori PL, Margarita V, Rappelli P, Dessì D. Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis. Front Microbiol 2021; 11:616213. [PMID: 33488560 PMCID: PMC7817646 DOI: 10.3389/fmicb.2020.616213] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/07/2020] [Indexed: 12/15/2022] Open
Abstract
Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.
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Affiliation(s)
- Fiona L Henriquez
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Ronnie Mooney
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Timothy Bandel
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Elisa Giammarini
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom
| | - Mohammed Zeroual
- School of Health and Life Sciences, University of West Scotland, Paisley, United Kingdom.,Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy
| | - Pier Luigi Fiori
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
| | - Valentina Margarita
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy
| | - Paola Rappelli
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
| | - Daniele Dessì
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy.,Mediterrenean Center for Disease Control, Sassari, Italy
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Niederkorn JY. The biology of Acanthamoeba keratitis. Exp Eye Res 2020; 202:108365. [PMID: 33221372 DOI: 10.1016/j.exer.2020.108365] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 12/31/2022]
Abstract
Acanthamoeba keratitis (AK) is a rare protozoal infection of the cornea. At least eight species of Acanthamoeba are known to cause this sight-threatening disease of the ocular surface. Acanthamoeba spp. exist in a wide array of niches ranging from thermal springs to under ice and every conceivable habitat in between. Contact lens wear is the leading risk factor for AK and is practiced by over 30 million individuals in the United States, yet the incidence of AK is less than 33 cases per one million contact lens wearers. Serological studies have reported that 90%-100% of individuals with no history of AK possess antibodies specific for Acanthamoeba antigens indicating that exposure to this organism is commonplace, yet disease is remarkably rare. Animal studies have shed light on the pathobiology and immunobiology of AK and indicate that a constellation of factors including the ocular surface microbiome and the microbiome of Acanthamoeba itself contribute to the pathogenesis of AK. Interesting, secretory antibodies produced by the adaptive immune response can prevent the initiation of corneal infection, but once Acanthamoeba trophozoites breach the corneal epithelium the adaptive immune system is helpless in altering the course of AK. It has been almost 50 years since AK was first described, yet many questions remain unanswered about this curious and enigmatic disease of the ocular surface.
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Affiliation(s)
- Jerry Y Niederkorn
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.
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Quan FS, Kong HH, Lee HA, Chu KB, Moon EK. Identification of differentially expressed Legionella genes during its intracellular growth in Acanthamoeba. Heliyon 2020; 6:e05238. [PMID: 33088972 PMCID: PMC7566939 DOI: 10.1016/j.heliyon.2020.e05238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/01/2020] [Accepted: 10/08/2020] [Indexed: 11/28/2022] Open
Abstract
Legionella grows intracellularly in free-living amoeba as well as in mammalian macrophages. Until now, the overall gene expression pattern of intracellular Legionella in Acanthamoeba was not fully explained. Intracellular bacteria are capable of not only altering the gene expression of its host, but it can also regulate the expression of its own genes for survival. In this study, differentially expressed Legionella genes within Acanthamoeba during the 24 h intracellular growth period were investigated for comparative analysis. RNA sequencing analysis revealed 3,003 genes from the intracellular Legionella. Among them, 115 genes were upregulated and 1,676 genes were downregulated more than 2 fold compared to the free Legionella. Gene ontology (GO) analysis revealed the suppression of multiple genes within the intracellular Legionella, which were categorized under 'ATP binding' and 'DNA binding' in the molecular function domain. Gene expression of alkylhydroperoxidase, an enzyme involved in virulence and anti-oxidative stress response, was strongly enhanced 24 h post-intracellular growth. Amino acid ABC transporter substrate-binding protein that utilizes energy generation was also highly expressed. Genes associated with alkylhydroperoxidase, glucose pathway, and Dot/Icm type IV secretion system were shown to be differentially expressed. These results contribute to a better understanding of the survival strategies of intracellular Legionella within Acanthamoeba.
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Affiliation(s)
- Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea.,Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan, Republic of Korea
| | - Hae-Ahm Lee
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Ki-Back Chu
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
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Moreno-Mesonero L, Hortelano I, Moreno Y, Ferrús MA. Evidence of viable Helicobacter pylori and other bacteria of public health interest associated with free-living amoebae in lettuce samples by next generation sequencing and other molecular techniques. Int J Food Microbiol 2020; 318:108477. [PMID: 31855786 DOI: 10.1016/j.ijfoodmicro.2019.108477] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/04/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022]
Abstract
Vegetables are one of the sources from which Helicobacter pylori can be acquired. This bacterium infects >50% of the global population and is a recognized type I human carcinogen. H. pylori enters into the viable but non-culturable state when it is in the environment, and therefore the use of molecular techniques is much convenient for its detection. Free-living amoebae (FLA) are protozoans found in vegetables. They are transmission vehicles for amoeba-resistant bacteria, among which H. pylori is included. The aim of this study is to study the occurrence and viability of H. pylori from lettuce samples, H. pylori internalized into FLA and the microbiome of FLA isolated from these samples. Special focus was pointed to human pathogenic bacteria. H. pylori was not directly detected in any lettuce sample by means of molecular techniques and neither by culture. However, intra-amoebic H. pylori DNA was detected by means of PMA-qPCR in 55% of the samples and viable intra-amoebic H. pylori cells in 25% of the samples by means of DVC-FISH technique. When FLA microbiome was studied, 21 bacterial genera were part of FLA microbiome in all samples. Helicobacter genus was detected as part of the FLA microbiome in two samples. Other bacteria of public health interest such as Aeromonas sp., Arcobacter sp., Legionella sp., Mycobacterium sp., Pseudomonas sp. and Salmonella sp. were detected as part of FLA microbiome along the analysed samples. This study demonstrates for the first time that H. pylori is internalized as well as alive inside FLA isolated from vegetables. Moreover, this study shows that FLA promote H. pylori detection in environmental samples. In addition, as far as we are aware, this is the first study which studies the microbiome of FLA isolated from vegetables. Among the FLA microbiome, bacteria of public health interest were detected, pointing out that FLA are carriers of these pathogens which can reach humans and cause a public health concern.
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Affiliation(s)
- Laura Moreno-Mesonero
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Irene Hortelano
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Yolanda Moreno
- Research Institute of Water and Environmental Engineering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Mª Antonia Ferrús
- Biotechnology Department, Universitat Politècnica de València, 46022 Valencia, Spain.
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Isolation and Phylogenetic Analysis of Free-Living Amoebae (Acanthamoeba, Naegleria, and Vermamoeba) in the Farmland Soils and Recreational Places in Iran. Acta Parasitol 2020; 65:36-43. [PMID: 31571139 DOI: 10.2478/s11686-019-00126-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/17/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE Free-living amoeba (FLA) including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria are among the soil-born parasites. There are reports of FLA-related keratitis with a history of contact with soil and dust sources, particularly among the farmers. Due to lack of the previous studies on the farmland soils and a limited number of researches conducted on recreational soils in Iran, the present study was conducted. METHODS A total of 93 soil samples including farming lands and recreational places were tested for the presence of Acanthamoeba spp. Balamuthia mandrillaris, Naegleria, and Vermamoeba using morphological key and sequencing-based tools. Pathogenicity of Acanthamoeba positive strains was also evaluated. To verify genetic associations and taxonomic status of isolated amoeba, a phylogenetic tree was built by MEGA 5.05 software inferred by the 18S rRNA gene based on maximum likelihood algorithm. RESULTS Overall, 28 samples (30%) were contaminated with potentially pathogenic FLA, and according to the sequencing data, 17 strains were successfully sequenced. The isolated Acanthamoeba belonged to T2, T4, T5, mixed T4 and T5 contaminations, and T11. ITS sequencing revealed the occurrence of one strain of Naegleria canariensis. Four strains of Vermamoeba vermiformis were also confirmed. Morphological survey and PCR assay failed to show any positive results for Balamuthia mandrillaris. Pathogenic potential of the Acanthamoeba strains showed that T2, T4, and T11 genotypes were highly pathogenic, whereas T5 genotypes demonstrated lower pathogenic potential. CONCLUSION The results indicate that soil could be a serious hazard to human health, and therefore, further studies are expected to investigate the source of infection in patients developing FLA-related diseases. The present study is the first to investigate FLA in the farmland soils in Iran and the first to report the presence of N. canariensis in the country.
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Fleiszig SMJ, Kroken AR, Nieto V, Grosser MR, Wan SJ, Metruccio MME, Evans DJ. Contact lens-related corneal infection: Intrinsic resistance and its compromise. Prog Retin Eye Res 2019; 76:100804. [PMID: 31756497 DOI: 10.1016/j.preteyeres.2019.100804] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 11/05/2019] [Accepted: 11/12/2019] [Indexed: 12/20/2022]
Abstract
Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.
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Affiliation(s)
- Suzanne M J Fleiszig
- School of Optometry, University of California, Berkeley, CA, USA; Graduate Group in Vision Science, University of California, Berkeley, CA, USA; Graduate Groups in Microbiology and Infectious Diseases & Immunity, University of California, Berkeley, CA, USA.
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, CA, USA
| | - Vincent Nieto
- School of Optometry, University of California, Berkeley, CA, USA
| | | | - Stephanie J Wan
- Graduate Group in Vision Science, University of California, Berkeley, CA, USA
| | | | - David J Evans
- School of Optometry, University of California, Berkeley, CA, USA; College of Pharmacy, Touro University California, Vallejo, CA, USA
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Mohd Hussain RH, Ishak AR, Abdul Ghani MK, Ahmed Khan N, Siddiqui R, Shahrul Anuar T. Occurrence and molecular characterisation of Acanthamoeba isolated from recreational hot springs in Malaysia: evidence of pathogenic potential. JOURNAL OF WATER AND HEALTH 2019; 17:813-825. [PMID: 31638031 DOI: 10.2166/wh.2019.214] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This study aimed to identify the Acanthamoeba genotypes and their pathogenic potential in five recreational hot springs in Peninsular Malaysia. Fifty water samples were collected between April and September 2018. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. All samples were filtered through the nitrocellulose membrane and tested for Acanthamoeba using both cultivation and polymerase chain reaction (PCR) by targeting the 18S ribosomal RNA gene. The pathogenic potential of all positive isolates was identified using thermo- and osmotolerance tests. Thirty-eight (76.0%) samples were positive for Acanthamoeba. Water temperature (P = 0.035), chemical oxygen demand (P = 0.026), sulphate (P = 0.002) and Escherichia coli (P < 0.001) were found to be significantly correlated with the presence of Acanthamoeba. Phylogenetic analysis revealed that 24 samples belonged to genotype T4, nine (T15), two (T3) and one from each genotype T5, T11 and T17. Thermo- and osmotolerance tests showed that 6 (15.79%) of the Acanthamoeba strains were highly pathogenic. The existence of Acanthamoeba in recreational hot springs should be considered as a health threat among the public especially for high-risk people. Periodic surveillance of hot spring waters and posting warning signs by health authorities is recommended to prevent disease related to pathogenic Acanthamoeba.
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Affiliation(s)
- Rosnani Hanim Mohd Hussain
- Centre of Medical Laboratory Technology, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia and Integrative Pharmacogenomics Institute, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia E-mail:
| | - Ahmad Razali Ishak
- Centre of Environmental Health and Safety, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia
| | - Mohamed Kamel Abdul Ghani
- Programme of Biomedical Sciences, School of Diagnostic and Applied Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Tengku Shahrul Anuar
- Centre of Medical Laboratory Technology, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia and Integrative Pharmacogenomics Institute, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia E-mail:
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Corticosteroid eye drop instillation aggravates the development of Acanthamoeba keratitis in rabbit corneas inoculated with Acanthamoeba and bacteria. Sci Rep 2019; 9:12821. [PMID: 31492880 PMCID: PMC6731293 DOI: 10.1038/s41598-019-49128-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/16/2019] [Indexed: 11/09/2022] Open
Abstract
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.
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Moreno Y, Moreno-Mesonero L, García-Hernández J. DVC-FISH to identify potentially pathogenic Legionella inside free-living amoebae from water sources. ENVIRONMENTAL RESEARCH 2019; 176:108521. [PMID: 31195295 DOI: 10.1016/j.envres.2019.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/11/2019] [Accepted: 06/01/2019] [Indexed: 06/09/2023]
Abstract
Despite all safety efforts, drinking and wastewater can still be contaminated by Legionella and free-living amoebae (FLA) since these microorganisms are capable of resisting disinfection treatments. An amoebae cyst harboring pathogenic Legionella spp. can be a transporter of this organism, protecting it and enhancing its infection abilities. Therefore, the aim of this work is to identify by DVC-FISH viable Legionella spp and Legionella pneumophila cells inside FLA from water sources in a specific and rapid way with the aim of assessing the real risk of these waters. A total of 55 water samples were processed, 30 reclaimed wastewater and 25 drinking water. FLA presence was detected in 52.7% of the total processed water samples. When DVC-FISH technique was applied, the presence of viable internalized Legionella spp. cells was identified in 69.0% of the total FLA-positive samples, concretely in 70.0% and 66.7% of wastewater and drinking water samples, respectively. L. pneumophila was simultaneously identified in 48.3% of the total FLA-positive samples, specifically in 50.0% and 44.4% of wastewater and drinking water samples, respectively. By culture, potentially pathogenic Legionella cells were recovered in 27.6% of the total FLA-positive bacteria, particularly in 35.0% and 11.1% of wastewater and drinking water samples, respectively. These findings demonstrate that FLA may promote resistance of bacteria to the performed disinfection treatments for drinking as well as for wastewater. So, in addition to the risk for the presence of pathogenic FLA in water it is necessary to take into account that these can be transporters of the pathogenic bacteria Legionella, which are able to survive inside them. The DVC-FISH method described here has been proved to be a rapid and specific tool to identify pathogenic Legionella spp. and L. penumophila viable cells harboured by FLA in these water sources, posing particular public health concern.
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Affiliation(s)
- Y Moreno
- Research Institute of Water and Environmental Ingeneering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain.
| | - L Moreno-Mesonero
- Research Institute of Water and Environmental Ingeneering (IIAMA), Universitat Politècnica de València, 46022 Valencia, Spain
| | - J García-Hernández
- Biotechnology Department, Universitat Politècnica de València, 46022 Valencia, Spain
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Jayasena Kaluarachchi TD, Weerasekera MM, McBain AJ, Ranasinghe S, Wickremasinghe R, Yasawardene S, Jayanetti N, Wickremasinghe R. Diagnosing Cutaneous leishmaniasis using Fluorescence in Situ Hybridization: the Sri Lankan Perspective. Pathog Glob Health 2019; 113:180-190. [PMID: 31429388 DOI: 10.1080/20477724.2019.1650228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cutaneous leishmaniasis (CL) caused by Leishmania donovani MON-37 is becoming a major public health problem in Sri Lanka, with 100 new cases per month being reported in endemic regions. Diagnosis of CL is challenging for several reasons. Due to relative specificity and rapidity we propose Fluorescence in Situ Hybridization as a diagnostic tool for CL. The objective was to evaluate the potential of Fluorescence in Situ Hybridization as a diagnostic method for Cutaneous leishmaniasis in Sri Lanka. Literature on current laboratory tests used to diagnose Cutaneous leishmaniasis in Sri Lanka and globally was reviewed. Sri Lankan data were reviewed systematically following the PRISMA guidelines. A narrative of the results is presented. There is currently no gold standard diagnostic method for Cutaneous leishmaniasis. Fluorescence in Situ Hybridization has been previously applied to detect dermal pathologies including those involving infectious agents, and its use to detect the Leishmania parasite in human cutaneous lesions reported in small number of studies, generally with limited numbers of subjects. Advantages of FISH has been specificity, cost and ease-of-use compared to the alternatives. Based on the available literature and our current work, FISH has potential for diagnosing CL and should now be evaluated in larger cohorts in endemic regions. FISH for CL diagnosis could find application in countries such as Sri Lanka, where laboratory facilities may be limited in rural areas where the disease burden is highest.
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Affiliation(s)
| | - Manjula Manoji Weerasekera
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura , Nugegoda , Sri Lanka
| | - Andrew J McBain
- Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura , Nugegoda , Sri Lanka.,Division of Pharmacy & Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester , Manchester
| | - Shalindra Ranasinghe
- Department of Parasitology, Faculty of Medical Sciences, University of Sri Jayewardenepura , Colombo , Sri Lanka
| | - Renu Wickremasinghe
- Department of Parasitology, Faculty of Medical Sciences, University of Sri Jayewardenepura , Colombo , Sri Lanka
| | - Surangi Yasawardene
- Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura , Colombo , Sri Lanka
| | - Nisal Jayanetti
- Department of Parasitology, Faculty of Medical Sciences, University of Sri Jayewardenepura , Colombo , Sri Lanka
| | - Rajitha Wickremasinghe
- Department of Public Health, Faculty of Medicine, University of Kelaniya , Kelaniya , Sri Lanka
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Kim BJ, Cha GY, Kim BR, Kook YH, Kim BJ. Insights From the Genome Sequence of Mycobacterium paragordonae, a Potential Novel Live Vaccine for Preventing Mycobacterial Infections: The Putative Role of Type VII Secretion Systems for an Intracellular Lifestyle Within Free-Living Environmental Predators. Front Microbiol 2019; 10:1524. [PMID: 31333625 PMCID: PMC6616192 DOI: 10.3389/fmicb.2019.01524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 06/18/2019] [Indexed: 12/31/2022] Open
Abstract
Mycobacterium paragordonae (Mpg) is a temperature-sensitive Mycobacterium species that can grow at permissive temperatures but fails to grow above 37°C. Due to this unique growth trait, Mpg has recently been proposed as a novel live vaccine candidate for the prevention of mycobacterial infections. Furthermore, the increasing frequency of the isolation of Mpg from water supply systems led us to hypothesize that the free-living amoeba system is the natural reservoir of Mpg. In this study, we report the complete 6.7-Mb genome sequence of Mpg and show that this genome comprises four different plasmids with lengths of 305 kb (pMpg-1), 144 kb (pMpg-2), 26 kb (pMpg-3), and 17 kb (pMpg-4). The first two plasmids, pMpg-1 and -2, encode distinct Type VII secretion systems (T7SS), ESX-P5 and ESX-2, respectively. Genome-based phylogeny indicated that Mpg is the closest relative to M. gordonae, which has a 7.7-Mb genome; phylogenetic analysis revealed an average of 86.68% nucleotide identity between these two species. The most important feature of Mpg genome is the acquisition of massive genes related to T7SS, which may have had effect on adaptation to their intracellular lifestyle within free-living environmental predators, such as amoeba. Comparisons of the resistance to bacterial killing within amoeba indicated that Mpg exhibited stronger resistance to amoeba killing compared to M. gordonae and M. marinum, further supporting our genome-based findings indicating the special adaptation of Mpg to free-living amoeba. We also determined that, among the strains studied, there were more shared CDS between M. tuberculosis and Mpg. In addition, the presence of diverse T7SSs in the Mpg genome, including an intact ESX-1, may suggest the feasibility of Mpg as a novel tuberculosis vaccine. Our data highlight a significant role of lateral gene transfer in the evolution of mycobacteria for niche diversification and for increasing the intracellular survival capacity.
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Affiliation(s)
- Byoung-Jun Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Ga-Yeong Cha
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Bo-Ram Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Yoon-Hoh Kook
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Bum-Joon Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Institute of Endemic Diseases, Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
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Abstract
Bacterial pathogens are generally investigated in the context of disease. To prevent outbreaks, it is essential to understand their lifestyle and interactions with other microbes in their natural environment. Legionella pneumophila is an important human respiratory pathogen that survives and multiplies in biofilms or intracellularly within protists, such as amoebae. Importantly, transmission to humans occurs from these environmental sources. Legionella infection generally leads to rapid host cell lysis. It was therefore surprising to observe that amoebae, including fresh environmental isolates, were well protected during Legionella infection when the bacterial symbiont Protochlamydia amoebophila was also present. Legionella was not prevented from invading amoebae but was impeded in its ability to develop fully virulent progeny and were ultimately cleared in the presence of the symbiont. This study highlights how ecology and virulence of an important human pathogen is affected by a defensive amoeba symbiont, with possibly major consequences for public health. Legionella pneumophila is an important opportunistic pathogen for which environmental reservoirs are crucial for the infection of humans. In the environment, free-living amoebae represent key hosts providing nutrients and shelter for highly efficient intracellular proliferation of L. pneumophila, which eventually leads to lysis of the protist. However, the significance of other bacterial players for L. pneumophila ecology is poorly understood. In this study, we used a ubiquitous amoeba and bacterial endosymbiont to investigate the impact of this common association on L. pneumophila infection. We demonstrate that L. pneumophila proliferation was severely suppressed in Acanthamoeba castellanii harboring the chlamydial symbiont Protochlamydia amoebophila. The amoebae survived the infection and were able to resume growth. Different environmental amoeba isolates containing the symbiont were equally well protected as different L. pneumophila isolates were diminished, suggesting ecological relevance of this symbiont-mediated defense. Furthermore, protection was not mediated by impaired L. pneumophila uptake. Instead, we observed reduced virulence of L. pneumophila released from symbiont-containing amoebae. Pronounced gene expression changes in the presence of the symbiont indicate that interference with the transition to the transmissive phase impedes the L. pneumophila infection. Finally, our data show that the defensive response of amoebae harboring P. amoebophila leaves the amoebae with superior fitness reminiscent of immunological memory. Given that mutualistic associations between bacteria and amoebae are widely distributed, P. amoebophila and potentially other amoeba endosymbionts could be key in shaping environmental survival, abundance, and virulence of this important pathogen, thereby affecting the frequency of human infection.
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Hajialilo E, Rezaeian M, Niyyati M, Pourmand MR, Mohebali M, Norouzi M, Razavi Pashabeyg K, Rezaie S, Khodavaisy S. Molecular characterization of bacterial, viral and fungal endosymbionts of Acanthamoeba isolates in keratitis patients of Iran. Exp Parasitol 2019; 200:48-54. [PMID: 30917916 DOI: 10.1016/j.exppara.2019.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/18/2019] [Accepted: 03/21/2019] [Indexed: 11/27/2022]
Abstract
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.
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Affiliation(s)
- Elham Hajialilo
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Rezaeian
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
| | - Maryam Niyyati
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad Reza Pourmand
- Department of Pathobiology, School of Public Health, Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Norouzi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Kobra Razavi Pashabeyg
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sassan Rezaie
- Division of Molecular Biology & Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sadegh Khodavaisy
- Division of Molecular Biology & Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Battaini A, La Scola B, Yin GHW, Hoffart L, Drancourt M. Amebaborne "Attilina massiliensis" Keratitis, France. Emerg Infect Dis 2019; 24:387-389. [PMID: 29350163 PMCID: PMC5782871 DOI: 10.3201/eid2402.170541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report a case of Acanthamoeba castellani keratitis in a person who wore contact lenses. The amebae hosted an ameba-resistant bacterial symbiont, provisionally named “Attilina massiliensis,” a yet undescribed α-Proteobacterium.
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Hsu CC. Dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas in an orthokeratology contact lens wearer. Taiwan J Ophthalmol 2019; 9:131-133. [PMID: 31198674 PMCID: PMC6557072 DOI: 10.4103/tjo.tjo_114_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Acanthamoeba species can cause a keratitis misdiagnosed as herpes keratitis or fungal keratitis. We report an unusual dendrite-like anterior stromal keratitis coinfected with Acanthamoeba and Pseudomonas aeruginosa in an orthokeratology contact lens wearer in Taiwan. Topical 1% voriconazole and 0.5% levofloxacin were prescribed because besides Acanthamoeba keratitis, fungal keratitis was also highly suspected initially. Topical 0.02% chlorhexidine was added after the culture of the scraped cornea showed positive results of Acanthamoeba and P. aeruginosa. The lesion subsided using this triple combination therapy for 1 week. Both Acanthamoeba and P. aeruginosa are potentially devastating causes of infectious keratitis. Our case highlights the importance of considering the possibility of a concurrent infection and atypical presentation in cases with contact lens-related keratitis. The use of topical levofloxacin combined with voriconazole should be considered as the first-line treatment in such patients.
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Affiliation(s)
- Chih-Chien Hsu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
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Identification of free-living amoebae isolated from tap water in Istanbul, Turkey. Exp Parasitol 2018; 195:34-37. [DOI: 10.1016/j.exppara.2018.10.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/03/2018] [Accepted: 10/13/2018] [Indexed: 12/26/2022]
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Ghaderifar S, Najafpoor AA, Zarrinfar H, Esmaily H, Hajialilo E. Isolation and identification of Acanthamoeba from pond water of parks in a tropical and subtropical region in the Middle East, and its relation with physicochemical parameters. BMC Microbiol 2018; 18:139. [PMID: 30340522 PMCID: PMC6195741 DOI: 10.1186/s12866-018-1301-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 10/04/2018] [Indexed: 12/02/2022] Open
Abstract
Background Free-living amoeba (FLA) are wide-spread protozoa that are found in different environmental sources including water, soil, dust, hospital units and ventilation areas. These amoebas can act as opportunistic or non-opportunistic pathogens. Among FLAs, some genera such as Acanthamoeba are important because of their potential pathogenic ability in humans. The purpose of this study is to identify of Acanthamoeba isolated from pond water of parks in a tropical and subtropical region in the Middle East, and its relation with physicochemical parameters.From August to December 2015, 90 samples were collected from pond water of parks of 13 regions of Mashhad City. Physicochemical parameters were measured in situ. After filtering, the samples were cultured on Bacto-agar enriched with Escherichia coli. PCR analysis was conducted on the culture-positive samples, and then the PCR products were sequenced. Statistical analysis was performed by SPSS software and Fisher’s Exact and Mann-Whitney test. Results Among the samples that were examined, 19 samples (21.1%) were positive for Acanthamoeba. The sequencing revealed that Acanthamoeba isolates belonged to T4 genotype of Acanthamoeba. There was no significant relationship between physicochemical parameters and the presence of Acanthamoeba. Conclusion The prevalence of Acanthamoeba in pond water of parks was relatively high, but there was no significant relationship between physicochemical parameters and the presence of Acanthamoeba.
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Affiliation(s)
- Shiva Ghaderifar
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Asghar Najafpoor
- Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. .,Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW, 2308, Iran.
| | - Hossein Zarrinfar
- Allergy Research Center Mashhad, University of Medical Sciences, Mashhad, Iran
| | - Habibollah Esmaily
- Department of Epidemiology and Biostatistics, University of Medical Sciences, Mashhad, Iran
| | - Elham Hajialilo
- Department of Medical Parasitology and Mycology, School of Medicine, Qazvin University of Medical Sciences, Qazvin, Iran
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