Characterization of the natural bacterial microbiota of pathogenic free-living amoebae (Acanthamoeba spp. and Naegleria fowleri) isolated from rivers and tap water in Guadeloupe

The Science of The Total Environment, Journal Year: 2025, Volume and Issue: 975, P. 179204 - 179204

Published: April 7, 2025

Free-living amoebae (FLA) are ubiquitous protists found in water, feeding mainly on bacteria. While most FLA harmless, Acanthamoeba spp. and Naegleria fowleri can cause keratitis and/or meningitis. host amoeba-resistant bacteria (ARB), but their natural bacterial microbiota is largely unknown. This study aimed to identify the of fowleri, castellanii, lenticulata, sp. T17, isolated from untreated (rivers) treated (tap) waters Guadeloupe. The whole water source grown with E. coli under axenic culture conditions, during successive passages, were characterized using 16S rRNA gene metabarcoding. culturable subset ARB was identified by mass spectrometry (MALDI-TOF MS) followed conventional PCR, antibiotic resistance analyzed disk diffusion method. Transmission electron microscopy used locate within amoebae. metabarcoding analyses Salmonella, Enterobacter Klebsiella genera as abundant waters. However, frequently detected (ARB) Bosea, Escherichia-Shigella, Microbacterium, Pseudomonas genera. Our findings revealed, for first time, occurrence several N. including Escherichia coli. Additionally, we Legionella A. castellanii Bordetella lenticulata. four pathogenic showed both temporary permanent associations various genera, depending number passages conditions. species distinct exhibited different antibiotics. cytoplasm trophozoites. presence Guadeloupe's drinking systems pose health risks. results highlight need regular monitoring ensure safety understanding amoebae-bacteria interactions better management. also questions immune response amoeba infection.

Language: Английский

An Evolutionary-Focused Review of the Holosporales (Alphaproteobacteria): Diversity, Host Interactions, and Taxonomic Re-ranking as Holosporineae Subord. Nov

Microbial Ecology, Journal Year: 2025, Volume and Issue: 88(1)

Published: March 14, 2025

Abstract The order Holosporales is a broad and ancient lineage of bacteria obligatorily associated with eukaryotic hosts, mostly protists. Significantly, this similar to other evolutionary distinct bacterial lineages (e.g. Rickettsiales Chlamydiae ). Here, we provide detailed comprehensive account on the current knowledge . First, acknowledging up-to-date phylogenetic reconstructions recent nomenclatural proposals, reevaluate their taxonomy, thus re-ranking them as suborder, i.e. Holosporineae , within Rhodospirillales Then, examine diversity presenting 20 described genera many yet undescribed sub-lineages, well variety respective environments provenance which belong several different supergroups. Noteworthy representatives are infectious intranuclear Holospora host manipulator ‘ Caedimonas ’, farmed shrimp pathogen Candidatus Hepatobacter’. Next, put these in context whole by comparing available data least studied representatives, including genome sequences. Accordingly, reason most probable trajectories for interactions, specificity, emergence potential pathogens aquaculture possibly humans, future research directions investigate those open points

Language: Английский