Mitochondrial DNA fingerprinting of Acanthamoeba spp. isolated from clinical and environmental sources

Gautom, Romesh; Lory, Stephen; Seyedirashti, Seyedreza; Bergeron, Dominique; Fritsche, Thomas R.

doi:10.1128/jcm.32.4.1070-1073.1994

Cited by 26 publications

(4 citation statements)

References 14 publications

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“…Traditional classi®cation of acanthamoebae was based on trophozoite and cyst morphology (Pussard and Pons, 1977), whereas only recently have molecular approaches, such as isoenzyme electrophoretic patterns, mitochondrial restriction fragment length polymorphism (RFLP) analysis and 18S rRNA sequence comparison, been applied (Daggett et al, 1985;Gautom et al, 1994;Stothard et al, 1998). The last method led to subdivision of the genus Acanthamoeba into 12 sequence types.…”

Section: Discussionmentioning

confidence: 99%

Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus

Horn

Fritsche

Gautom

et al. 1999

Environmental Microbiology

186

135

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Acanthamoebae are increasingly being recognized as hosts for obligate bacterial endosymbionts, most of which are presently uncharacterized. In this study, the phylogeny of three Gram-negative, rod-shaped endosymbionts and their Acanthamoeba host cells was analysed by the rRNA approach. Comparative analyses of 16S rDNA sequences retrieved from amoebic cell lysates revealed that the endosymbionts of Acanthamoeba polyphaga HN-3, Acanthamoeba sp. UWC9 and Acanthamoeba sp. UWE39 are related to the Paramecium caudatum endosymbionts Caedibacter caryophilus, Holospora elegans and Holospora obtusa. With overall 16S rRNA sequence similarities to their closest relative, C. caryophilus, of between 87% and 93%, these endosymbionts represent three distinct new species. In situ hybridization with fluorescently labelled endosymbiont-specific 16S rRNA-targeted probes demonstrated that the retrieved 16S rDNA sequences originated from the endosymbionts and confirmed their intracellular localization. We propose to classify provisionally the endosymbiont of Acanthamoeba polyphaga HN-3 as 'Candidatus Caedibacter acanthamoebae', the endosymbiont of Acanthamoeba sp. strain UWC9 as 'Candidatus Paracaedibacter acanthamoebae' and the endosymbiont of Acanthamoeba sp. strain UWE39 as 'Candidatus Paracaedibacter symbiosus'. The phylogeny of the Acanthamoeba host cells was analysed by comparative sequence analyses of their 18S rRNA. Although Acanthamoeba polyphaga HN-3 clearly groups together with most of the known Acanthamoeba isolates (18S rRNA sequence type 4), Acanthamoeba sp. UWC9 and UWE39 exhibit <92% 18S rRNA sequence similarity to each other and to other Acanthamoeba isolates. Therefore, we propose two new sequence types (T13 and T14) within the genus Acanthamoeba containing, respectively, Acanthamoeba sp. UWC9 and Acanthamoeba sp. UWE39.

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Section: Discussionmentioning

confidence: 99%

Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus

Horn

Fritsche

Gautom

et al. 1999

Environmental Microbiology

186

135

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“…Analyses in our lab of genomic mitochondrial DNA RFLP (mtRFLP) [2, 51 indicated a high degree of variation among Acanthamoeba isolates. However, more recently, several labs have been able to cluster strains based on identical mtRFLP [ 17,24,411. Unfortunately, the published literature indicates few strains that have been examined both with mtRFLP and Rns sequences.…”

Section: A Griffini S-7 T3mentioning

confidence: 99%

“…In addition to detection, diagnosis and classification, interest in the function and evolution of processes in Acanthamoeba will undoubtedly be stimulated by recent discoveries, which include the complete sequence of the mitochondrial genome of Acanthamoeba castellanii Neff [4], the identification of the first cases of mitochondrial tRNA editing [27, 281 and Cyst size and structure have been used to divide species of Acanthamoeba into morphological Groups I, I1 and 111 [36]. Further study of intrageneric relationships has been based on criteria such as isoenzyme patterns [l I, 12, 211, physiological characteristics [9], immunological reactivities [ 131, mitochondrial DNA restriction fragment length polymorphisms (mt-RFLP) [2,10,17,411, and partial sequences of nuclear small subunit rRNA [23]. In spite of these various approaches, inconsistencies in classification persist.…”

mentioning

confidence: 99%

Subgenus Systematics of Acanthamoeba: Four Nuclear 18S rDNA Sequence Types

Gast

Ledee

Fuerst

et al. 1996

J Eukaryotic Microbiology

178

146

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Classification of Acanthamoeba at the subgenus level has been problematic, but increasing reports of Acanthamoeba as an opportunistic human pathogen have generated an interest in finding a more consistent basis for classification. Thus, we are developing a classification scheme based on RNA gene sequences. This first report is based on analysis of complete sequences of nuclear small ribosomal subunit RNA genes (Rns) from 18 strains. Sequence variation was localized in 12 highly variable regions. Four distinct sequence types were identified based on parsimony and distance analyses. Three were obtained from single strains: Type T1 from Acanthamoeba castellanii V006, T2 from Acanthamoeba palestinensis Reich, and T3 from Acanthamoeba griffini S‐7. T4, the fourth sequence type, included 15 isolates classified as A. castellanii, Acanthamoeba polyphaga, Acanthamoeba rhysodes, or Acanthamoeba sp., and included all 10 Acanthamoeba keratitis isolates. Interstrain sequence differences within T4 were 0%–4.3%, whereas differences among sequence types were 6%–12%. Branching orders obtained by parsimony and distance analyses were inconsistent with the current classification of T4 strains and provided further evidence of a need to reevaluate criteria for classification in this genus. Based on this report and others in preparation, we propose that Rns sequence types provide the consistent quantititive basis for classification that is needed.

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“…Acanthamoeba keratitis development may be occluded in the presence of Langerhans cells in corneas of parasite-burdened contact lens [32]. Also, potassium hydroxide mount provides for rapid diagnosis and differential diagnosis of Acanthamoeba and fungal keratitis [33], Mitochondrial DNA (mtDNA ingerprinting) evaluation as a tool to identify potential reservoirs of Acanthamoeba infection illustrated that environmental isolate inclusion expounded that the most common clinical isolates have recoverable partners from the proximity with ostensible spatial dissemination [34]. Due to its rapidity, easy access or availability, decreased labourintensity, and realization of its 18s rRNA region to detect Acanthamoeba in clinical samples, as well as its sensitivity and speci icity, it is clear that polymerase chain reaction is a remarkable improvement for Acanthamoeba detection [35].…”

Section: Clinical Microbial Diagnosismentioning

confidence: 99%

Explicating the presentations of Acanthamoeba keratitis with special concern in the COVID-19 pandemic ambient

Chukwuma¹

2021

Int J Clin Microbiol Biochem Technol

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This article presents an overview of information regarding Acanthamoeba keratitis per epidemiology, host-pathogen interactions, clinical manifestations, risk factors, environmental implications, diagnosis, treatment and management as well as COVID-19 characteristics which may be taken into cognizance for suspected infected patients, researchers and ophthalmologic practitioners. Acanthamoeba spp. is pathogenetically ubiquitous in nature. Acanthamoeba keratitis is considerably an ocular-threatening and debilitating keratitis that exhibits contumacious characteristics which hinder or impede treatment or management. At inception, Acanthamoeba generally depicts atypical clinical features which are frequently misdiagnosed as other microbial keratitis. Fundamentally, it constitutes a rare corneal infection of which the aetiologic agent is the protozoon Acanthamoeba spp. in contact lens wearers, presenting features of severe ophthalmic distress, blurred vision, blepharospasm, ocular excoriation, extraneous entity sensation and photophobia culminating in aberrant visual functionality. These are perspicuously due to retarded prompt and adequate treatment and management. Personal and environmental hygiene, especially on the hands, face and ocular areas as advised for the COVID-19 protocol could prevent contamination and dissemination of Acanthamoeba keratitis infection. The differentiating relatedness of Acanthamoeba keratitis, COVID-19 ophthalmologic infections and other ocular problems may not have been clearly elucidated.

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Mitochondrial DNA fingerprinting of Acanthamoeba spp. isolated from clinical and environmental sources

Cited by 26 publications

References 14 publications

Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus

Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus

Subgenus Systematics of Acanthamoeba: Four Nuclear 18S rDNA Sequence Types

Explicating the presentations of Acanthamoeba keratitis with special concern in the COVID-19 pandemic ambient

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