المؤلفون: Nona S. R. Agawin, Guillem Ramis-Munar, Antoni Bennasar-Figueras, Víctor Fernández-Juárez, Antoni Sureda-Gomila

المصدر: Frontiers in Microbiology, Vol 11 (2020)
Frontiers in Microbiology

مصطلحات موضوعية: Microbiology (medical), Cyanobacteria, lcsh:QR1-502, chemistry.chemical_element, Halothece sp. PCC 7418, Microbiology, nitrogen, lcsh:Microbiology, 03 medical and health sciences, Pigment, chemistry.chemical_compound, Nutrient, iron, Nitrate, phosphorus, N2-fixation, 030304 developmental biology, Original Research, Fischerella muscicola PCC 73103, 0303 health sciences, Strain (chemistry), biology, 030306 microbiology, Chemistry, Phosphorus, Pho–Fur–NtcA regulon, biology.organism_classification, Nitrogen, reactive oxygen species production, visual_art, Environmental chemistry, visual_art.visual_art_medium, Diazotroph

الوصف: Diazotrophs or N2-fixers are one of the most ecologically significant groups in marine ecosystems (pelagic and benthic). Inorganic phosphorus (PO43-) and iron (Fe) can limit the growth and N2-fixing capacities of cyanobacteria. However, studies investigating co-limitation of these factors are lacking. Here, we added different concentrations of PO43- and Fe in two cyanobacterial species whose relatives can be found in seagrass habitats: the unicellular Halothece sp. (PCC 7418) and the filamentous Fischerella muscicola (PCC 73103), grown under different nitrate (NO3-) concentrations and under N2 as sole N source, respectively. Their growth, pigment content, N2-fixation rates, oxidative stress responses, and morphological and cellular changes were investigated. Our results show a serial limitation of NO3- and PO43- (with NO3- as the primary limiting nutrient) for Halothece sp. Simultaneous co-limitation of PO43- and Fe was found for both species tested, and high levels of Fe (especially when added with high PO43- levels) inhibited the growth of Halothece sp. Nutrient limitation (PO43-, Fe, and/or NO3-) enhanced oxidative stress responses, morphological changes, and apoptosis. Furthermore, an extensive bio-informatic analysis describing the predicted Pho, Fur, and NtcA regulons (involved in the survival of cells to P, Fe, and N limitation) was made using the complete genome of Halothece sp. as a model, showing the potential of this strain to adapt to different nutrient regimes (P, Fe, or N).

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::773da480cbe34f5a790dad8054cef335
https://www.frontiersin.org/article/10.3389/fmicb.2020.541558/full

المؤلفون: Rosa M. Gomila, Pedro Echeveste, Guillem Ramis-Munar, Víctor Fernández-Juárez, Nona S. R. Agawin, Xabier López-Alforja, Antoni Bennasar-Figueras, Aida Frank-Comas

المصدر: Frontiers in Microbiology
Frontiers in Microbiology, Vol 11 (2021)

مصطلحات موضوعية: Microbiology (medical), Cyanobacteria, Microplastics, microplastics, Heterotroph, lcsh:QR1-502, cyanobacteria and heterotrophic bacteria, 010501 environmental sciences, 01 natural sciences, Microbiology, lcsh:Microbiology, 03 medical and health sciences, Marine bacteriophage, N2-fixing bacteria, Autotroph, Food science, 030304 developmental biology, 0105 earth and related environmental sciences, Original Research, 0303 health sciences, Microbial food web, biology, Chemistry, biology.organism_classification, marine pollution, organic additives, Diazotroph, Bacteria

الوصف: Little is known about the direct effects of microplastics (MPs) and their organic additives on marine bacteria, considering their role in the nutrient cycles, e.g., N-cycles through the N2-fixation, or in the microbial food web. To fill this gap of knowledge, we exposed marine bacteria, specifically diazotrophs, to pure MPs which differ in physical properties (e.g., density, hydrophobicity, and/or size), namely, polyethylene, polypropylene, polyvinyl chloride and polystyrene, and to their most abundant associated organic additives (e.g., fluoranthene, 1,2,5,6,9,10-hexabromocyclododecane and dioctyl-phthalate). Growth, protein overproduction, direct physical interactions between MPs and bacteria, phosphorus acquisition mechanisms and/or N2-fixation rates were evaluated. Cyanobacteria were positively affected by environmental and high concentrations of MPs, as opposed to heterotrophic strains, that were only positively affected with high concentrations of ~120 μm-size MPs (detecting the overproduction of proteins related to plastic degradation and C-transport), and negatively affected by 1 μm-size PS beads. Generally, the organic additives had a deleterious effect in both autotrophic and heterotrophic bacteria and the magnitude of the effect is suggested to be dependent on bacterial size. Our results show species-specific responses of the autotrophic and heterotrophic bacteria tested and the responses (beneficial: the “good,” deleterious: the “bad” and/or both: the “double-sword”) were dependent on the type and concentration of MPs and additives. This suggests the need to determine the threshold levels of MPs and additives concentrations starting from which significant effects can be observed for key microbial populations in marine systems, and these data are necessary for effective environmental quality control management.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1f9892691615a4c000d3fae64fa3771d
https://pubmed.ncbi.nlm.nih.gov/33552008

المؤلفون: Nuria Salas-Massó, Alberto Lema, Sabela Balboa, Alba Pérez-Cataluña, Ana L. Diéguez, Jesús L. Romalde, M.J. Figueras

المصدر: Frontiers in Microbiology
Frontiers in Microbiology, Vol 10 (2019)

مصطلحات موضوعية: Microbiology (medical), Arcobacter, 0303 health sciences, 030306 microbiology, Aliiarcobacter gen. nov, Haloarcobacter gen. nov, lcsh:QR1-502, Correction, Pseudoarcobacter gen. nov, Microbiology, lcsh:Microbiology, 03 medical and health sciences, Malacobacter gen. nov, Geography, Poseidonibacter gen. nov, Genus, Taxonomy (general), taxonomic criteria, Order (group theory), Genus Arcobacter, 030304 developmental biology

الوصف: The original paper, which contained a description of five new genera with 25 species (all new combinations) contained many errors that prevented the proposed names from being included in a Validation List in the International Journal of Systematic and Evolutionary Microbiology. The List Editors could correct part of the problems, so that the generic names Pseudarcobacter, Malaciobacter. Halarcobacter, and Poseidonibacter and the species assigned as “comb. nov.” to these genera could be validly published [Oren, A. and Garrity, G. M. (2019). List of new names and new combinations previously effectively, but not validly, published. Validation List no. 185. Int. J. Syst. Evol. Microbiol. 69, 5–9]. The corrections made are explained in footnotes to the list. However, because of the nature of some of the changes required, the List Editors could not make the corrections for the proposed genus “Aliiarcobacter” and the eight proposed new combinations in the Validation List. The corrigendum published [Revisiting the Taxonomy of the Genus Arcobacter: Getting Order From the Caos (sic), by Perez-Cataluna, A., Salas- Masso, N., Dieguez, A. L., Balboa, S., Lema, A., Romalde, J. L., et al. (2018). Front. Microbiol. 9:3123. doi: 10.3389/fmicb.2018.03123] failed to correct the remaining errors and introduced new problems. This necessitated a new Corrigendum in order to effectively publish the names Aliarcobacter and eight “comb. nov.” species to be submitted subsequently for List validation in the International Journal of Systematic and Evolutionary Microbiology.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::83f7a408da786865c2d934ba18dbba65
http://europepmc.org/articles/PMC6779803

المؤلفون: Nona S. R. Agawin, Antoni Bennasar-Figueras, Antonio Tovar-Sánchez, Víctor Fernández-Juárez

المصدر: Digital.CSIC. Repositorio Institucional del CSIC
instname
Frontiers in Microbiology, Vol 10 (2019)

مصطلحات موضوعية: Cyanobacteria, Microbiology (medical), Phosphatase, lcsh:QR1-502, chemistry.chemical_element, Halothece sp. PCC 7418, Microbiology, lcsh:Microbiology, N2 fixation, PO43--Fe uptake, PhoU, 03 medical and health sciences, chemistry.chemical_compound, iron, Alkaline phosphatase, Botany, 030304 developmental biology, PhoD, 0303 health sciences, biology, 030306 microbiology, Phosphorus, Posidonia oceanica, biology.organism_classification, Phosphate, chemistry, Epiphyte, Bacteria

الوصف: Posidonia oceanica, an endemic seagrass of the Mediterranean Sea harbors a high diversity of N-fixing prokaryotes. One of these is Halothece sp., a unicellular N-fixing cyanobacteria detected through nifH analysis from the epiphytes of P. oceanica. The most related strain in culture is Halothece sp. PCC 7418 and this was used as the test organism in this study. In the Mediterranean Sea, phosphorus (P) and iron (Fe) can be the major limiting nutrients for N fixation. However, information about the mechanisms of P-acquisition and the role of metals (i.e., Fe) in these processes for N-fixing bacteria is scarce. From our genomic analyses of the test organism and other phylogenetically related N-fixing strains, Halothece sp. PCC 7418 is one of the strains with the greatest number of gene copies (eight copies) of alkaline phosphatases (APases). Our structural analysis of PhoD (alkaline phosphatase type D) and PhoU (phosphate acquisition regulator) of Halothece sp. PCC 7418 showed the connection among metals (Ca and Fe), and the P-acquisition mechanisms. Here, we measured the rates of alkaline phosphatase activity (APA) through MUF-P hydrolysis under different combinations of concentrations of inorganic P ( PO ) and Fe in experiments under N-fixing (low NO availability) and non-N fixing (high NO availability) conditions. Our results showed that APA rates were enhanced by the increase in Fe availability under low levels of PO, especially under N-fixing conditions. Moreover, the increased PO-uptake was reflected in the increased of the P-cellular content of the cells under N fixation conditions. We also found a positive significant relationship between cellular P and cellular Fe content of the cells (r = 0.71, p < 0.05). Our results also indicated that Fe-uptake in Halothece sp. PCC 7418 was P and Fe-dependent. This study gives first insights of P-acquisition mechanisms in the N-fixing cyanobacteria (Halothece sp.) found in P. oceanica and highlights the role of Fe in these processes.
This work was supported by funding to NA through the Agencia Estatal de Investigación and the European Regional Development Funds project (CTM2016-75457-P).

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::02b01be1d2d4ee52cb74a6e90fe233c7

المؤلفون: Maria José Figueras, Sabela Balboa, Ana L. Diéguez, Jesús L. Romalde, Nuria Salas-Massó, Alba Pérez-Cataluña, Alberto Lema

المصدر: Frontiers in Microbiology, Vol 9 (2018)

مصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Arcobacter, 030106 microbiology, Haloarcobacter gen. nov, lcsh:QR1-502, Biology, Pseudoarcobacter gen. nov, biology.organism_classification, Microbiology, Aliarcobacter gen. nov, lcsh:Microbiology, 03 medical and health sciences, Malacobacter gen. nov, 030104 developmental biology, Poseidonibacter gen. nov, Evolutionary biology, Taxonomy (biology), Genus Arcobacter

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f53497ded0e2f2de12f9f79cf5074cf7
https://www.frontiersin.org/article/10.3389/fmicb.2018.03123/full

المؤلفون: Nuria, Salas-Massó, Quyen Than, Linh, Wai Hoe, Chin, Anders, Wolff, Karl B, Andree, M Dolors, Furones, María José, Figueras, Dang Duong, Bang

المصدر: Frontiers in Microbiology

مصطلحات موضوعية: Arcobacter, qPCR, shellfish, Microbiology, viable cells, Original Research, PMA

الوصف: The genus Arcobacter (Vandamme et al., 1991), comprised of Campylobacter-related species, are considered zoonotic emergent pathogens. The presence of Arcobacter in food products like shellfish, has an elevated incidence worldwide. In this study, we developed a specific viable quantitative PCR (v-qPCR), using the dye propidium monoazide (PMA), for quantification of the viable Arcobacter spp. cells in raw oysters and mussels. The high selectivity of primers was demonstrated by using purified DNA from 38 different species, 20 of them from the genus Arcobacter. The optimization of PMA concentration showed that 20 μM was considered as an optimal concentration that inhibits the signal from dead cells at different concentrations (OD550 from 0.2 to 0.8) and at different ratios of live: dead cells (50:50 and 90:10). The v-qPCR results from shellfish samples were compared with those obtained in parallel using several culture isolation approaches (i.e., direct plating on marine and blood agar and by post-enrichment culturing in both media). The enrichment was performed in parallel in Arcobacter-CAT broth with and without adding NaCl. Additionally, the v-qPCR results were compared to those obtained with traditional quantitative (qPCR). The v-qPCR and the qPCR resulted in c.a. 94% of positive detection of Arcobacter vs. 41% obtained by culture approaches. When examining the reduction effect resulting from the use of v-qPCR, samples pre-enriched in Arcobacter-CAT broth supplemented with 2.5% NaCl showed a higher reduction (3.27 log copies) than that of samples obtained directly and those pre-enriched in Arcobacter-CAT broth isolation (1.05 and 1.04). When the v-qPCR was applied to detect arcobacter from real shellfish samples, 15/17 samples tested positive for viable Arcobacter with 3.41 to 8.70 log copies 1g-1. This study offers a new tool for Arcobacter surveillance in seafood.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=pmid________::877a91a36041dd78c98085d4c8260ce8
https://pubmed.ncbi.nlm.nih.gov/30873146

المؤلفون: Maria José Figueras, Oscar Salgado, Luis Collado, Alba Pérez-Cataluña, Violeta Lefiñanco

المصدر: Frontiers in Microbiology
Frontiers in Microbiology, Vol 9 (2018)

مصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Species complex, Arcobacter cryaerophilus, genomovar, In silico, 030106 microbiology, lcsh:QR1-502, Biology, Genome, Animal origin, Microbiology, lcsh:Microbiology, 03 medical and health sciences, isDDH, Original Research, 2. Zero hunger, Genetics, Phylogenetic tree, Genomovar, food and beverages, 6. Clean water, MLPA, 030104 developmental biology, ANI, Taxonomy (biology)

الوصف: The species Arcobacter cryaerophilus is found in many food products of animal origin and is the dominating species in wastewater. In addition, it is associated with cases of farm animal and human infectious diseases,. The species embraces two subgroups i.e., 1A (LMG 24291T = LMG 9904T) and 1B (LMG 10829) that can be differentiated by their 16S rRNA-RFLP pattern. However, some authors, on the basis of the shared intermediate levels of DNA-DNA hybridization, have suggested abandoning the subgroup classification. This contradiction indicates that the taxonomy of this species is not yet resolved. The objective of the present study was to perform a taxonomic evaluation of the diversity of A. cryaerophilus. Genomic information was used along with a Multilocus Phylogenetic Analysis (MLPA) and phenotypic characterization on a group of 52 temporally and geographically dispersed strains, coming from different types of samples and hosts from nine countries. The MLPA analysis showed that those strains formed four clusters (I-IV). Values of Average Nucleotide Identity (ANI) and in silico DNA-DNA Hybridization (isDDH) obtained between 13 genomes representing strains of the four clusters were below the proposed cut-offs of 96 and 70%, respectively, confirming that each of the clusters represented a different genomic species. However, none of the evaluated phenotypic tests enabled their unequivocal differentiation into species. Therefore, the genomic delimited clusters should be considered genomovars of the species A. cryaerophilus. These genomovars could have different clinical importance, since only the cluster I included strains isolated from human specimens. The discovery of at least one stable distinctive phenotypic character would be needed to define each cluster or genomovar as a different species. Until then, we propose naming them "A. cryaerophilus gv. pseudocryaerophilus" (Cluster I = LMG 10229T), "A. cryaerophilus gv. crypticus" (Cluster II = LMG 9065T), "A. cryaerophilus gv. cryaerophilus" (Cluster III = LMG 24291T) and "A. cryaerophilus gv. occultus" (Cluster IV = LMG 29976T).

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::15322ea15804a0934fe8672ac88ecb46

المؤلفون: Antonio Figueras, Juan M. Tomás, Susana Merino, Paolo R. Saraceni, Alejandro Romero, Beatriz Novoa

المساهمون: Ministerio de Economía y Competitividad (España), Universitat de Barcelona

المصدر: Frontiers in Microbiology, Vol 7 (2016)
Digital.CSIC. Repositorio Institucional del CSIC
instname
Dipòsit Digital de la UB
Universidad de Barcelona
Recercat. Dipósit de la Recerca de Catalunya
ResearcherID

مصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Zebra danio, animal structures, Lipopolysaccharide, Larves, Peix zebra, Ratolins (Animals de laboratori), Virulence Factors, 030106 microbiology, Mutant, lcsh:QR1-502, Virulence, Flagellum, Microbiology, lcsh:Microbiology, In vivo infection, 03 medical and health sciences, chemistry.chemical_compound, Mice, Larvae, Zebrafish larvae, Zebrafish, Mutant Aeromonas, biology, Virulence factors, animal model, fungi, Wild type, in vivo infection, Anatomy, biology.organism_classification, rainbow trout, Animal models, 030104 developmental biology, Mice (Laboratory animals), Rainbow trout, chemistry, Aeromonas, Pathogenic bacteria, Bacteris patògens, Bacteria

الوصف: 11 páginas, 6 figuras, 2 tablas.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms
The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of Aeromonas hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analyzed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-11vapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild-type. Variations between models were evidenced using the AH-11rmlB, which lacks the O-antigen lipopolysaccharide (LPS), and the AH-11wahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH- 11FlaB-J (lacking polar flagella and unable to swim) and the AH-1::motX (non-motile but producing flagella). They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study demonstrates that zebrafish larvae can be used as a host model to assess the virulence factors of A. hydrophila. This model revealed more differences in pathogenicity than the in vitro models and enabled the detection of slight variations in pathogenesis not observed using intraperitoneal injections of mice or fish
This work was partially funded by the projects CSD2007-00002 “Aquagenomics”, AGL2014-51773-C3, 201230E057 (CSIC) and BIO2013-47198-P, from the Spanish Ministerio de Economía y Competitividad, from Generalitat de Catalunya (Centre de Referència en Biotecnologia), and from ITN 289209 (FISHFORPHARMA) (EU). PR Saraceni received a Marie Curie Fellowship from the EU

وصف الملف: application/pdf

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::27cdf128f5a466676119fafaef47cd54
http://journal.frontiersin.org/Journal/10.3389/fmicb.2016.01574/full

المؤلفون: Craig A. Shoemaker, De-Hai Xu, Mark R. Liles, Maria José Figueras, Joseph C. Newton, Cody R. Rasmussen-Ivey, Matt J. Griffin, Sara E. Odom, William G. Hemstreet, Yongjie Liu, Mohammad J. Hossain, Scott R. Santos, Dunhua Zhang, Jeffery S. Terhune

المساهمون: Unitat de Micologia i Microbiologia Ambiental, Ciències Mèdiques Bàsiques, Universitat Rovira i Virgili

المصدر: Frontiers in Microbiology, Vol 7 (2016)
Frontiers In Microbiology
Frontiers in Microbiology

مصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Lineage (evolution), 030106 microbiology, lcsh:QR1-502, Context (language use), Pathogenesis, Microbiology, lcsh:Microbiology, 03 medical and health sciences, emerging disease, Original Research, Genetics, Comparative genomics, Ciències de la salut, catFISH, biology, Phylogenetic tree, Bacteria, Peixos -- Malalties, carp, Outbreak, Health sciences, biology.organism_classification, Ciencias de la salud, 1664-302X, Aeromonas hydrophila, 030104 developmental biology, Aeromonas, Catfish

الوصف: Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251) share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila, with 26 identified as epidemic strains. Phylogenetic analyses indicate all ST251 strains form a coherent lineage affiliated with A. hydrophila. Within this lineage, conserved genetic loci unique to A. hydrophila were identified, with some genes present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates support the conclusion that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes. These studies revealed that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS). In contrast, more virulent US isolates retain only remnants of the T6SS (clpB, hcp, vgrG, and vasH) which may have functional implications. Collectively, these results characterize a hypervirulent A. hydrophila pathotype that affects farmed fish on multiple continents.

وصف الملف: 5896 kb

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e223ce19951c3013654440a8383290f2
http://journal.frontiersin.org/Journal/10.3389/fmicb.2016.01615/full

المؤلفون: Maria José Figueras, Peter Teunis

المصدر: Frontiers in Microbiology, Vol 7 (2016)
Frontiers in Microbiology

مصطلحات موضوعية: 0301 basic medicine, Microbiology (medical), Salmonella, Aeromonas caviae, 030106 microbiology, water, lcsh:QR1-502, infective dose, medicine.disease_cause, Microbiology, lcsh:Microbiology, challenge study, risk of illness, 03 medical and health sciences, medicine, Original Research, risk of infection, biology, Campylobacter, food, Outbreak, biology.organism_classification, 3. Good health, Diarrhea, Aeromonas hydrophila, Aeromonas, outbreaks, medicine.symptom, Aeromonas veronii

الوصف: Cases of Aeromonas diarrhea have been described all over the world. The genus Aeromonas includes ca. 30 species, of which 10 have been isolated in association with gastroenteritis. The dominating species that account for ca. 96% of the identified strains are Aeromonas caviae, Aeromonas veronii, Aeromonas dhakensis and Aeromonas hydrophila. However, the role of Aeromonas as a true enteropathogen has been questioned on the basis of the lack of outbreaks, the non-fulfilment of Koch’s postulates and the low numbers of acute illnesses in the only existing human challenge study. In the present study we reassess the enteropathogenicity of Aeromonas using dose response models for microbial infection and acute illness. The analysis uses the data from the human challenge study and additional data from selected outbreak investigations where the numbers exposed and the dose were reported, allowing their inclusion as natural experiments. In the challenge study several cases of asymptomatic shedding were found (26.3%, 15/57), however, only 3.5% (2/57) of those challenged with Aeromonas developed acute enteric symptoms (i.e. diarrhea). The natural experiments showed a much higher risk of illness associated with exposure to Aeromonas, even at moderate to low doses. The median dose required for 1% illness risk, was ~1.4x104 times higher in the challenge study (1.24x104 cfu) compared to natural exposure events (0.9 cfu). The dose response assessment presented in this study shows that the combined challenge and outbreak data are consistent with high infectivity of Aeromonas, and a wide range of susceptibility to acute enteric illness. To illustrate the outcomes, we simulate the risk associated with concentrations of Aeromonas found in different water and food matrices, indicating the disease burden potentially associated with these bacteria. In conclusion this study showed that Aeromonas is highly infectious, and that human susceptibility to illness may be high, similar to undisputed enteropathogens like Campylobacter or Salmonella.

URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::26df8290e7d9bbacb1fe6af133839997