First identification of Naegleria species and Vahlkampfia ciguana in Nile water, Cairo, Egypt: Seasonal morphology and phylogenetic analysis

El-Badry, Ayman A.; Aufy, Sayeda M; El-Wakil, Eman S.; Rizk, E.; Mahmoud, Soheir; Taha, Nahed Y.

doi:10.1016/j.jmii.2018.06.003

Cited by 11 publications

(12 citation statements)

References 27 publications

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“…Besides the identification of N. australiensis and N. philippinensis, this study also identified N. canariensis , N. gruberi and a Vahlkampfia spp through the same morphological approach combined with sequencing analysis. The potential of the selected primers to amplify two distinct free-living amoeba genera, Naegleria and Vahlkahmpfia, has been recently reported in two studies one from the Nile River, Egypt [49] and the other from regions of Malaysia [50]. Taking into account the isolation of Vahlkampfia lobospinosa from cattle feces and the use of the Monjolinho river by domestic animals, our finding is consistent with the presence of free living amoeba, and potentially pathogenic species [51].…”

Section: Naegleria Spp Diversity In Brazilsupporting

confidence: 88%

“…The DNA was amplified with Naegleria genus-specific oligodesoxirribonucleotides, Ng.spp_FW 5´-GAACCTGCGTAGGGATCATTT-3´ and Ng.spp_RV 5´-TTTCTTTTCCTCCCCTTATTA-3´, to the internal transcribed spacer regions (ITS1 and 2) that comprise the 5.8S rDNA gene previously adopted in phylogenetic studies [43,49,50,56,57]. The PCR reactions contained Taq High Fidelity Pol Master Mix 2x (Red, Cellco Biotec), 100 ng of the DNA template and 200 nmoles of each primer.…”

Section: Dna Extraction Amplification and Sequencingmentioning

confidence: 99%

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Isolation of <em>Naegleria spp.</em> from a Brazilian Water Source

Bellini¹,

Fonseca²,

Reyes-Batllé³

et al. 2019

Preprint

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The genus Naegleria, of free-living amoeba (FLA) group, has been investigated mainly due to its human health impact resulting in deadly infections and their worldwide distribution on freshwater systems. Naegleria fowleri, colloquially known as the “brain-eating amoeba”, is the most studied Naegleria species because it causes Primary Amoebic Meningoencephalitis (PAM) of high lethality. The assessment of FLA biodiversity is fundamental to evaluate the presence of pathogenic species and the possibility of human contamination. However, the knowledge of FLA distribution in Brazil is unknown, and to rectify this situation we present a research on identifying Naegleria spp. in the Monjolinho River, as a model study. The river is a public Brazilian freshwater source that crosses the city of São Carlos. Five distinct sampling sites were examined through limnological features, trophozoites culturing and PCR against internal transcribed spacers (ITS) regions and 5.8S rRNA sequence. The results identified N. philippinensis, N. canariensisi, N. australiensis, N.gruberi, N. dobsoni sequences, as well as a Vahlkampfia sequence. The methodology delineated here represents the first Brazilian Naegleria spp. study on a freshwater system. Our result stresses the urgency of a large scale evaluation of the presence of free-living amoebas in Brazil.

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Section: Naegleria Spp Diversity In Brazilsupporting

confidence: 88%

Section: Dna Extraction Amplification and Sequencingmentioning

confidence: 99%

Isolation of <em>Naegleria spp.</em> from a Brazilian Water Source

Bellini¹,

Fonseca²,

Reyes-Batllé³

et al. 2019

Preprint

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“…The amoebae identified as Vahlkampfia grouped closer to the species Vahlkampfia inornata than to Vahlkampfia avara . Like Tetramitus , this amoebal genus has been isolated from environmental samples but remains poorly described and studied ( 35 , 45 , 46 ). Two amoebae were identified as Stemonitis (formerly Hyperamoeba ), amoebae that are close to slime molds and whose phylogeny has long been a source of debate ( 47 , 48 ).…”

Section: Resultsmentioning

confidence: 99%

Environmental Free-Living Amoebae Can Predate on Diverse Antibiotic-Resistant Human Pathogens

Bornier

Zas

Potheret

et al. 2021

Appl Environ Microbiol

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We here sought to test the resistance of human pathogens to unaltered environmental free-living amoebae. Amoebae are ubiquitous eukaryotic microorganisms and important predators of bacteria. Environmental amoebae have also been proposed to serve both as potential reservoir and training ground for human pathogens. However, studies addressing their relationship with human pathogens often rely on a few domesticated amoebae selected to feed on rich medium, thereby possibly overestimating the resistance of pathogens to these predatory phagocytes. From an open-air composting site, we recovered over a hundred diverse amoebae able to feed on Acinetobacter baumannii and Klebsiella pneumoniae . In a standardized and quantitative assay for predation, the isolated amoebae showed a broad predation spectrum, killing clinical isolates of A. baumannii , K. pneumoniae , Pseudomonas aeruginosa and Staphylococcus aureus . Interestingly, A. baumannii , previously reported to resist predation by laboratory strains of Acanthamoeba , is efficiently consumed by closely related environmental amoebae. The isolated amoebae are capable of feeding on highly virulent carbapenem-resistant or methicillin-resistant clinical isolates. In conclusion, the natural environment is a rich source of amoebae with broad-spectrum bactericidal activities, including against antibiotic resistant isolates. Importance Free-living amoebae have been proposed to play in important role in hosting and disseminating various human pathogens. The resistance of human pathogens to predation by amoebae is often derived from in vitro experiments using model amoebae. We here sought to isolate environmental amoebae and test their predation on diverse human pathogens, with results that challenge conclusions based on model amoebae. We found that the natural environment is a rich source of diverse amoebae with broad-spectrum predatory activities against human pathogens, including highly virulent and antibiotic resistant clinical isolates.

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“…through the same morphological approach combined with sequencing analysis, as shown by the bootstrap supported phylogenetic tree (Figure 4), although the short length of the ITS-5.8S sequences did not resolve the polytomy within each species. The potential of the selected primers to amplify two distinct free-living amoeba genera has been recently reported in two studies from the Nile River, Egypt [38] and from regions of Malaysia [39]. By analyzing the DNA sequences that were directly extracted from the river water (Table 1), one additional Naegleria species could be identified: N. dobsoni.…”

Section: Naegleria Spp Diversity In Brazilmentioning

confidence: 89%

“…The DNA was amplified with Naegleria genus-specific primers, Ng.spp_FW 5 -GAACCTGCGTAG GGATCATTT-3 and Ng.spp_RV 5 -TTTCTTTTCCTCCCCTTATTA-3 , to the internal transcribed spacer regions (ITS1 and 2) that comprise the 5.8S rDNA gene that was previously adopted in phylogenetic studies [37][38][39][40][41]. The PCR reactions contained Taq High Fidelity Pol Master Mix 2x (Red, Cellco Biotec, São Carlos, Brazil), 100 ng of the DNA template, and 200 nmoles of each primer.…”

Section: Dna Extraction Amplification and Sequencingmentioning

confidence: 99%

Isolation of Naegleria spp. from a Brazilian Water Source

et al. 2020

View full text Add to dashboard Cite

The genus Naegleria, of the free-living amoeba (FLA) group, has been investigated mainly due to its human health impact, resulting in deadly infections and their worldwide distribution on freshwater systems. Naegleria fowleri, colloquially known as the “brain-eating amoeba,” is the most studied Naegleria species because it causes primary amoebic meningoencephalitis (PAM) of high lethality. The assessment of FLA biodiversity is fundamental to evaluate the presence of pathogenic species and the possibility of human contamination. However, the knowledge of FLA distribution in Brazil is unknown, and to rectify this situation, we present research on identifying Naegleria spp. in the Monjolinho River as a model study. The river is a public Brazilian freshwater source that crosses the city of São Carlos, in São Paulo state, Brazil. Five distinct sampling sites were examined through limnological features, trophozoites culturing, and PCR against internal transcribed spacer (ITS) regions and 5.8S rRNA sequences. The results identified N. philippinensis, N. canariensisi, N. australiensis, N. gruberi, N. dobsoni sequences, as well as a Hartmannella sequence. The methodology delineated here represents the first Brazilian Naegleria spp. study on a freshwater system. Our results stress the urgency of a large scale evaluation of the presence of free-living amoebas in Brazil.

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First identification of Naegleria species and Vahlkampfia ciguana in Nile water, Cairo, Egypt: Seasonal morphology and phylogenetic analysis

Cited by 11 publications

References 27 publications

Isolation of <em>Naegleria spp.</em> from a Brazilian Water Source

Isolation of <em>Naegleria spp.</em> from a Brazilian Water Source

Environmental Free-Living Amoebae Can Predate on Diverse Antibiotic-Resistant Human Pathogens

Isolation of Naegleria spp. from a Brazilian Water Source

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