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1.
Environ Microbiol ; 26(1): e16562, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38173299

RESUMEN

Holosporales are an alphaproteobacterial order engaging in obligate and complex associations with eukaryotes, in particular protists. The functional and evolutionary features of those interactions are still largely undisclosed. Here, we sequenced the genomes of two members of the species Bealeia paramacronuclearis (Holosporales, Holosporaceae) intracellularly associated with the ciliate protist Paramecium, which resulted in high correspondence. Consistent with the short-branched early-divergent phylogenetic position, Bealeia presents a larger functional repertoire than other Holosporaceae, comparable to those of other Holosporales families, particularly for energy metabolism and motility. Our analyses indicate that different Holosporales likely experienced at least partly autonomous genome reduction and adaptation to host interactions, for example regarding dependence on host biotin driven by multiple independent horizontal acquisitions of transporters. Among Alphaproteobacteria, this is reminiscent of the convergently evolved Rickettsiales, which however appear more diverse, possibly due to a probably more ancient origin. We identified in Bealeia and other Holosporales the plasmid-encoded putative genetic determinants of R-bodies, which may be involved in a killer trait towards symbiont-free hosts. While it is not clear whether these genes are ancestral or recently horizontally acquired, an intriguing and peculiar role of R-bodies is suggested in the evolution of the interactions of multiple Holosporales with their hosts.


Asunto(s)
Alphaproteobacteria , Paramecium , Humanos , Alphaproteobacteria/genética , Filogenia , Genómica , Paramecium/microbiología , Eucariontes/genética , Simbiosis/genética
2.
J Health Polit Policy Law ; 49(1): 133-162, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37522380

RESUMEN

CONTEXT: A key task for countries around the world facing the COVID-19 pandemic was to achieve high vaccination coverage of the population. To overcome "vaccination inertia," governments adopted a variety of policy instruments. These instruments can be placed along a "ladder of intrusiveness" based on their degree of constraint of individual freedoms. The aim of this study is to investigate how the governments of three European countries moved along the ladder of intrusiveness and how the choice of policy instruments was influenced by contextual factors. METHODS: The study draws on secondary data sources, including academic and gray literature, policy documents, and opinion polls, over an observation period from December 2020 to summer 2022. The study employs inductive logic to analyze data and identify the factors explaining similarities and differences across England, Germany, and Italy. FINDINGS: The study identifies similarities and differences in how the three countries advanced along the ladder of intrusiveness. Contextual factors such as policy legacy, social acceptability, and ideological orientation contribute to explain the observations. CONCLUSIONS: Country-specific contextual factors play an important role in understanding the choice of policy instruments adopted by the three countries. Policy makers should carefully consider these factors when planning immunization strategies.


Asunto(s)
COVID-19 , Vacunas , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Pandemias , Vacunación , Política de Salud
3.
Environ Microbiol ; 25(11): 2102-2117, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37305924

RESUMEN

Midichloria spp. are intracellular bacterial symbionts of ticks. Representatives of this genus colonise mitochondria in the cells of their hosts. To shed light on this unique interaction we evaluated the presence of an intramitochondrial localization for three Midichloria in the respective tick host species and generated eight high-quality draft genomes and one closed genome, showing that this trait is non-monophyletic, either due to losses or multiple acquisitions. Comparative genomics supports the first hypothesis, as the genomes of non-mitochondrial symbionts are reduced subsets of those capable of colonising the organelles. We detect genomic signatures of mitochondrial tropism, including the differential presence of type IV secretion system and flagellum, which could allow the secretion of unique effectors and/or direct interaction with mitochondria. Other genes, including adhesion molecules, proteins involved in actin polymerisation, cell wall and outer membrane proteins, are only present in mitochondrial symbionts. The bacteria could use these to manipulate host structures, including mitochondrial membranes, to fuse with the organelles or manipulate the mitochondrial network.


Asunto(s)
Ixodes , Animales , Ixodes/microbiología , Bacterias/genética , Mitocondrias/genética , Filogenia , Simbiosis
4.
Int Microbiol ; 2023 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-37615902

RESUMEN

Protists frequently host diverse bacterial symbionts, in particular those affiliated with the order Holosporales (Alphaproteobacteria). All characterised members of this bacterial lineage have been retrieved in obligate association with a wide range of eukaryotes, especially multiple protist lineages (e.g. amoebozoans, ciliates, cercozoans, euglenids, and nucleariids), as well as some metazoans (especially arthropods and related ecdysozoans). While the genus Paramecium and other ciliates have been deeply investigated for the presence of symbionts, known members of the family "Candidatus Paracaedibacteraceae" (Holosporales) are currently underrepresented in such hosts. Herein, we report the description of "Candidatus Intestinibacterium parameciiphilum" within the family "Candidatus Paracaedibacteraceae", inhabiting the cytoplasm of Paramecium biaurelia. This novel bacterium is almost twice as big as its relative "Candidatus Intestinibacterium nucleariae" from the opisthokont Nuclearia and does not present a surrounding halo. Based on phylogenetic analyses of 16S rRNA gene sequences, we identified six further potential species-level lineages within the genus. Based on the provenance of the respective samples, we investigated the environmental distribution of the representatives of "Candidatus Intestinibacterium" species. Obtained results are consistent with an obligate endosymbiotic lifestyle, with protists, in particular freshwater ones, as hosts. Thus, available data suggest that association with freshwater protists could be the ancestral condition for the members of the "Candidatus Intestinibacterium" genus.

5.
Parasitol Res ; 122(3): 881-887, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36640182

RESUMEN

Nematodes of the genus Dictyocaulus are the causative agents of parasitic bronchitis and pneumonia in several domestic and wild ungulates. Various species have been described in wild cervids, as the case of Dictyocaulus cervi in red deer, recently described as a separate species from Dictyocaulus eckerti. In Italy, information on dictyocaulosis in wildlife is limited and often outdated. In this work, 250 red deer were examined for the presence of Dictyocaulus spp. in two areas of the Italian Alps (n = 104 from Valle d'Aosta, n = 146 from Stelvio National Park), and the retrieved lungworms were molecularly characterized. Lungworms were identified in 23 and 32 animals from Valle d'Aosta and Stelvio National Park, respectively. The nematodes, morphologically identified as D. cervi, were characterized molecularly (18S rDNA, ITS2, and coxI). Consistently, almost all specimens were found to be phylogenetically related to D. cervi. Three individuals, detected from both study sites and assigned to an undescribed Dictyocaulus sp., clustered with Dictyocaulus specimens isolated from red deer and fallow deer in previous studies. Within each of D. cervi and the undescribed Dictyocaulus sp., the newly isolated nematodes phylogenetically clustered based on their geographical origin. This study revealed the presence of D. cervi in Italian red deer, and an undetermined Dictyocaulus sp. that should be more deeply investigated. The results suggest that further analyses should be focused on population genetics of cervids and their lungworms to assess how they evolved, or co-evolved, throughout time and space and to assess the potential of transmission towards farmed animals.


Asunto(s)
Ciervos , Infecciones por Dictyocaulus , Nematodos , Animales , Dictyocaulus/genética , Animales Salvajes/parasitología , Ciervos/parasitología , Infecciones por Dictyocaulus/epidemiología , Infecciones por Dictyocaulus/parasitología
6.
Environ Microbiol ; 23(3): 1684-1701, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33470507

RESUMEN

Members of the bacterial order Rickettsiales are obligatorily associated with a wide range of eukaryotic hosts. Their evolutionary trajectories, in particular concerning the origin of shared or differential traits among distant sub-lineages, are still poorly understood. Here, we characterized a novel Rickettsiales bacterium associated with the ciliate Paramecium tredecaurelia and phylogenetically related to the Rickettsia genus. Its genome encodes significant lineage-specific features, chiefly the mevalonate pathway gene repertoire, involved in isoprenoid precursor biosynthesis. Not only this pathway has never been described in Rickettsiales, it also is very rare among bacteria, though typical in eukaryotes, thus likely representing a horizontally acquired trait. The presence of these genes could enable an efficient exploitation of host-derived intermediates for isoprenoid synthesis. Moreover, we hypothesize the reversed reactions could have replaced canonical pathways for producing acetyl-CoA, essential for phospholipid biosynthesis. Additionally, we detected phylogenetically unrelated mevalonate pathway genes in metagenome-derived Rickettsiales sequences, likely indicating evolutionary convergent effects of independent horizontal gene transfer events. Accordingly, convergence, involving both gene acquisitions and losses, is highlighted as a relevant evolutionary phenomenon in Rickettsiales, possibly favoured by plasticity and comparable lifestyles, representing a potentially hidden origin of other more nuanced similarities among sub-lineages.


Asunto(s)
Paramecium , Filogenia , ARN Ribosómico 16S/genética , Rickettsiales/genética , Simbiosis/genética
7.
Environ Microbiol ; 23(1): 36-50, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32686279

RESUMEN

Phytophagous stink bugs typically harbor nutritional symbiotic bacteria in their midgut, to integrate their unbalanced diet. In the Pentatomidae, most symbionts are affiliated to the genus Pantoea, and are polyphyletic. This suggests a scenario of an ancestral establishment of symbiosis, followed by multiple symbiont replacement events by akin environmental bacteria in different host lineages. In this study, a novel Pantoeaspecies ('CandidatusPantoea persica') was characterized from the gut of the pentatomid Acrosternum arabicum, and shown to be highly abundant in a specific portion of the gut and necessary for the host development. The genome of the symbiont (2.9 Mb), while presenting putative host-supportive metabolic pathways, including those for amino acids and vitamin synthesis, showed a high level of pseudogenization, indicating ongoing genome reduction. Comparative analyses with other free-living and symbiotic Pantoea highlighted a convergent pattern of genome reduction in symbionts of pentatomids, putatively following the typical phases modelized in obligate nutritional symbionts of insects. Additionally, this system has distinctive traits, as hosts are closely related, and symbionts originated multiple independent times from closely related free-living bacteria, displaying convergent and independent conspicuous genome reduction. Due to such peculiarities, this may become an ideal model to study genome evolutionary processes in insect symbionts.


Asunto(s)
Genoma Bacteriano , Heterópteros/microbiología , Pantoea/genética , Simbiosis , Animales , Evolución Molecular , Heterópteros/fisiología , Redes y Vías Metabólicas , Pantoea/clasificación , Pantoea/aislamiento & purificación , Pantoea/fisiología , Filogenia
8.
Foodborne Pathog Dis ; 18(4): 267-275, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33493413

RESUMEN

Consumption of raw food, especially smoked fish, meat, soft cheeses, and vegetables, contaminated with Listeria monocytogenes can cause listeriosis, which can be invasive in pregnant women, elderly, and immunocompromised and diabetic patients. Through June to November of 2017, 11 patients developed invasive listeriosis in a small area of northern Italy. In the same period, 15 food samples (ready-to-eat seafood, raw vegetables, cheese samples, and salami) collected during the routine screening programs in the same area were found to be contaminated with L. monocytogenes. We characterized the isolates to determine the relatedness of L. monocytogenes strains isolated from patients and isolates from food samples and food-processing plants. Whole genome sequencing analysis showed that multiple L. monocytogenes strains were circulating in the area and no association was found between clinical and food isolates.


Asunto(s)
Manipulación de Alimentos/estadística & datos numéricos , Microbiología de Alimentos/estadística & datos numéricos , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Adulto , Anciano , Queso/microbiología , Femenino , Humanos , Huésped Inmunocomprometido/inmunología , Italia/epidemiología , Listeria monocytogenes/genética , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Masculino , Carne/microbiología , Persona de Mediana Edad , Alimentos Marinos/microbiología , Verduras/microbiología , Secuenciación Completa del Genoma
9.
World Dev ; 140: 105257, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33814676

RESUMEN

The extraordinary global growth of digital connectivity has generated optimism that mobile technologies can help overcome infrastructural barriers to development, with 'mobile health' (mhealth) being a key component of this. However, while 'formal' (top-down) mhealth programmes continue to face challenges of scalability and sustainability, we know relatively little about how health-workers are using their own mobile phones informally in their work. Using data from Ghana, Ethiopia and Malawi, we document the reach, nature and perceived impacts of community health-workers' (CHWs') 'informal mhealth' practices, and ask how equitably these are distributed. We implemented a mixed-methods study, combining surveys of CHWs across the three countries, using multi-stage proportional-to-size sampling (N = 2197 total), with qualitative research (interviews and focus groups with CHWs, clients and higher-level stake-holders). Survey data were weighted to produce nationally- or regionally-representative samples for multivariate analysis; comparative thematic analysis was used for qualitative data. Our findings confirm the limited reach of 'formal' compared with 'informal' mhealth: while only 15% of CHWs surveyed were using formal mhealth applications, over 97% reported regularly using a personal mobile phone for work-related purposes in a range of innovative ways. CHWs and clients expressed unequivocally enthusiastic views about the perceived impacts of this 'informal health' usage. However, they also identified very real practical challenges, financial burdens and other threats to personal wellbeing; these appear to be borne disproportionately by the lowest-paid cadre of health-workers, especially those serving rural areas. Unlike previous small-scale, qualitative studies, our work has shown that informal mhealth is already happening at scale, far outstripping its formal equivalent. Policy-makers need to engage seriously with this emergent health system, and to work closely with those on the ground to address sources of inequity, without undermining existing good practice.

10.
Exp Appl Acarol ; 83(3): 427-448, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33646482

RESUMEN

In many areas of Africa, recent studies highlighted the great impact of ticks on animal and human health throughout the continent. On the other hand, very limited information on the bacterial endosymbionts of the African ticks and their pattern of co-infections with other bacteria are found in literature, notwithstanding their pivotal role in tick survival and vector efficiency. Thus, we investigated the distribution of selected pathogenic and symbiotic bacteria in hard ticks collected from wild, domestic animals and from vegetation in various ecological zones in Africa and their co-occurrence in the same tick host. Overall, 339 hard ticks were morphologically identified as belonging to the genera Amblyomma, Dermacentor, Hyalomma, Haemaphysalis, Ixodes and Rhipicephalus. Molecular screening provided information on pathogens circulation in Africa, detecting spotted fever group rickettsiae, Anaplasma spp., Ehrlichia ruminantium, Borrelia garinii, Babesia spp., Theileria spp. and Coxiella burnetii. Furthermore, our work provides insights on the African scenario of tick-symbiont associations, revealing the presence of Coxiella, Francisella and Midichloria across multiple tick populations. Coxiella endosymbionts were the most prevalent microorganisms, and that with the broadest spectrum of hosts, being detected in 16 tick species. Francisella was highly prevalent among the Hyalomma species tested and correlated negatively with the presence of Coxiella, showing a potential competitive interaction. Interestingly, we detected a positive association of Francisella with Rickettsia in specimens of Hy. rufipes, suggesting a synergistic interaction between them. Finally, Midichloria was the most prevalent symbiont in Rhipicephalus sanguineus sensu lato from Egypt.


Asunto(s)
Rickettsia , Enfermedades por Picaduras de Garrapatas , África , Animales , Animales Domésticos , Animales Salvajes , Egipto/epidemiología , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/veterinaria
11.
Infection ; 48(2): 223-230, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31758437

RESUMEN

PURPOSE: The recurrence of multi-drug resistant (MDR) pathogens to the latest antibiotics and the limited development of new antibacterial agents have reduced the options for the treatment of severe infections. The reintroduction of old antibiotics, such as colistin, represents an effective strategy, since the latest antibiotics are over-consumed and ineffective against MDR pathogens. In 2015, Liu (Lancet Infect Dis 16:161-168, 2016) reported Escherichia coli (E. coli) isolates carrying plasmid-mediated colistin resistance gene mcr-1. The first of mcr-1 positive colistin-resistant (col-R) E. coli from a human blood culture was observed in 2012 in Latin America, while in Italy was reported for the first time by our center in 2016. The present study aimed to describe the prevalence of mcr-1 positive col-R strains in E. coli-related bloodstream infection among patients hospitalized in Fondazione IRCCS Policlinico San Matteo in Pavia, Italy, from 2012 to 2018, including the three cases already published. METHODS: All col-R E. coli strains isolated from blood cultures collected during the study period were analyzed. The minimal inhibitory concentration of colistin was determined using broth microdilution and detection of mcr-1 and mcr-2 genes was performed by PCR. The sequence type of E. coli mcr-1 positive was determined according to Multilocus sequence typing. RESULTS: Out of 1557 samples, 14 strains (0.90%) were col-R. and positive for the presence of the mcr-1 gene, with no mcr-2 detected. The most common ST was ST10 (n = 3), followed by ST410 (n = 2). The remaining strains exhibited different MLST profiles, indicating that they were genetically unrelated. CONCLUSIONS: Proper reporting of the presence of mcr-1 genes is an essential component to anticipate the spread of colistin resistance. This public health issue is particularly alarming in Italy due to the consistent circulation of MDR bacteria.


Asunto(s)
Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Enfermedades Hematológicas/microbiología , Hospitalización/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Femenino , Enfermedades Hematológicas/epidemiología , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
12.
Microb Ecol ; 77(3): 748-758, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30105505

RESUMEN

Symbioses between bacteria and eukaryotes are widespread and may have significant impact on the evolutionary history of symbiotic partners. The order Rickettsiales is a lineage of intracellular Alphaproteobacteria characterized by an obligate association with a wide range of eukaryotic hosts, including several unicellular organisms, such as ciliates and amoebas. In this work, we characterized the Rickettsiales symbionts associated with two different genotypes of the freshwater ciliate Paramecium caudatum originated from freshwater environments in distant geographical areas. Phylogenetic analyses based on 16S rRNA gene showed that the two symbionts are closely related to each other (99.4% identity), belong to the family Rickettsiaceae, but are far-related with respect to previously characterized Rickettsiales. Consequently, they were assigned to a new species of a novel genus, namely "Candidatus Spectririckettsia obscura." Screening on a database of short reads from 16S rRNA gene amplicon-based profiling studies confirmed that bacterial sequences related to the new symbiont are preferentially retrieved from freshwater environments, apparently with extremely scarce occurrence (< 0.1% positive samples). The present work provides new information on the still under-explored biodiversity of Rickettsiales, in particular those associated to ciliate host cells.


Asunto(s)
Paramecium caudatum/microbiología , Rickettsiales/fisiología , Simbiosis , Brasil , ADN Bacteriano/genética , India , Filogenia , ARN Ribosómico 16S/genética , Rickettsiales/genética , Rickettsiales/aislamiento & purificación
13.
Appl Environ Microbiol ; 82(24): 7236-7247, 2016 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-27742680

RESUMEN

In the past 10 years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, IN. Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium "Candidatus Bealeia paramacronuclearis" occurs in clumps and is frequently associated with the host macronucleus. With its electron-dense cytoplasm and a distinct halo surrounding the cell, it is easily distinguishable from the second smaller symbiont, "Candidatus Fokinia cryptica," whose cytoplasm is electron lucid, lacks a halo, and is always surrounded by a symbiontophorous vacuole. For molecular characterization, the small-subunit rRNA genes were sequenced and used for taxonomic assignment as well as the design of species-specific oligonucleotide probes. Phylogenetic analyses revealed that "Candidatus Bealeia paramacronuclearis" clusters with the so-called "basal" Rickettsiales, and "Candidatus Fokinia cryptica" belongs to "Candidatus Midichloriaceae." We obtained tree topologies showing a separation of Rickettsiales into at least two groups: one represented by the families Rickettsiaceae, Anaplasmataceae, and "Candidatus Midichloriaceae" (RAM clade), and the other represented by "basal Rickettsiales," including "Candidatus Bealeia paramacronuclearis." Therefore, and in accordance with recent publications, we propose to limit the order Rickettsiales to the RAM clade and to raise "basal Rickettsiales" to an independent order, Holosporales ord. nov., inside Alphaproteobacteria, which presently includes four family-level clades. Additionally, we define the family "Candidatus Hepatincolaceae" and redefine the family Holosporaceae IMPORTANCE: In this paper, we provide the characterization of two novel bacterial symbionts inhabiting the same Paramecium host (Ciliophora, Alveolata). Both symbionts belong to "traditional" Rickettsiales, one representing a new species of the genus "Candidatus Fokinia" ("Candidatus Midichloriaceae"), and the other representing a new genus of a "basal" Rickettsiales According to newly characterized sequences and to a critical revision of recent literature, we propose a taxonomic reorganization of "traditional" Rickettsiales that we split into two orders: Rickettsiales sensu stricto and Holosporales ord. nov. This work represents a critical revision, including new records of a group of symbionts frequently occurring in protists and whose biodiversity is still largely underestimated.


Asunto(s)
Alphaproteobacteria/aislamiento & purificación , Citoplasma/microbiología , Paramecium/microbiología , Rickettsiaceae/aislamiento & purificación , Alphaproteobacteria/clasificación , Alphaproteobacteria/genética , Alphaproteobacteria/fisiología , Paramecium/fisiología , Filogenia , Rickettsiaceae/clasificación , Rickettsiaceae/genética , Rickettsiaceae/fisiología , Simbiosis
14.
Microb Ecol ; 71(2): 505-17, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26381539

RESUMEN

Several ciliated protists form symbiotic associations with a diversity of microorganisms, leading to drastic impact on their ecology and evolution. In this work, two Euplotes spp. sampled in Rio de Janeiro, Brazil, were identified based on morphological and molecular features as Euplotes woodruffi strain Sq1 and E. encysticus strain Sq2 and investigated for the presence of endosymbionts. While E. woodruffi Sq1 stably hosts two bacterial populations, namely Polynucleobacter necessarius (Betaproteobacteria) and a new member of the family "Candidatus Midichloriaceae" (Alphaproteobacteria, Rickettsiales), here described as "Candidatus Bandiella woodruffii," branching with a broad host range bacterial group found in association with cnidarians, sponges, euglenoids, and some arthropods; in E. encysticus Sq2 no symbiotic bacterium could be detected. The dispersion ability of this novel bacterium was tested by co-incubating E. woodruffi Sq1 with three different ciliate species. Among the tested strains "Ca. B. woodruffii" could only be detected in association with E. encysticus Sq2 with a prevalence of 20 % after 1 week and 40 % after 2 weeks, maintaining this level for up to 6 months. Nevertheless, this apparent in vitro association was abolished when E. woodruffi Sq1 donor was removed from the microcosm, suggesting that this bacterium has the capacity for at least a short-term survival outside its natural host and the aptitude to ephemerally interact with other organisms. Together, these findings strongly suggest the need for more detailed investigations to evaluate the host range for "Ca. B. woodruffii" and any possible pathogenic effect of this bacterium on other organisms including humans.


Asunto(s)
Bacterias/aislamiento & purificación , Euplotes/microbiología , Bacterias/clasificación , Bacterias/genética , Fenómenos Fisiológicos Bacterianos , Brasil , Euplotes/clasificación , Euplotes/fisiología , Especificidad del Huésped , Datos de Secuencia Molecular , Filogenia , Simbiosis
15.
Curr Microbiol ; 72(6): 723-32, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26894821

RESUMEN

Large-scale studies on obligate bacterial endosymbionts may frequently require preliminary purification and enrichment protocols, which are often elaborate to set up and to evaluate, especially if the host organism is a protist. The purpose of this study was to develop a real-time PCR-based strategy and employ it for assessing two of such enrichment protocols for Holospora caryophila, hosted by the ciliate Paramecium. Four SSU rRNA gene-targeted real-time PCR assays were designed, which allowed to compare the amount of H. caryophila to other organisms, namely the host, its food bacterium (Raoultella planticola), and free-living bacteria present in the culture medium. By the use of the real-time PCR assays in combination, it was possible to conclude that the "cell fractionation" protocol was quite successful in the enrichment of the symbiont, while the "Percoll gradient" protocol will need further refinements to be fully repeatable. The proposed approach has the potential to facilitate and encourage future studies on the yet underexplored field of bacterial endosymbionts of ciliates and other protists. It can also find valuable applications for experimental questions other than those tested, such as fast and precise assessment of symbiont abundance in natural populations and comparison among multiple coexisting symbionts.


Asunto(s)
Bacterias/aislamiento & purificación , Técnicas de Tipificación Bacteriana/métodos , Cilióforos/microbiología , Simbiosis , Bacterias/clasificación , Bacterias/genética , Fenómenos Fisiológicos Bacterianos , Biodiversidad , Cilióforos/fisiología , ADN Bacteriano/genética , Filogenia , ARN Ribosómico 16S/genética , Reacción en Cadena en Tiempo Real de la Polimerasa
16.
Microb Ecol ; 70(2): 484-97, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25704316

RESUMEN

We report the characterization of the bacterial consortium associated to Euplotes focardii, a strictly psychrophilic marine ciliate that was maintained in laboratory cultures at 4 °C after its first isolation from Terra Nova Bay, in Antarctica. By Illumina genome analyser, we obtained 11,179 contigs of potential prokaryotic origin and classified them according to the NCBI's prokaryotic attributes table. The majority of these sequences correspond to either Bacteroidetes (16 %) or Proteobacteria (78 %). The latter were dominated by gamma- (39 %, including sequences related to the pathogenic genus Francisella), and alpha-proteobacterial (30 %) sequences. Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in "transmembrane transporter activity" and "oxidoreductase activity". Furthermore, we identified genes that encode for enzymes involved in the catabolism of complex substance for energy reserves. We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins. Antibiotic treatments of E. focardii cultures delayed the cell division of the ciliate. To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition. Furthermore, our results suggest that these bacteria may have a more general role in E. focardii survival in its natural cold and oxidative environment.


Asunto(s)
Euplotes/genética , Adaptación Fisiológica , Regiones Antárticas , Genómica/métodos , Consorcios Microbianos
17.
Ticks Tick Borne Dis ; 15(1): 102285, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38035456

RESUMEN

Ticks are important vectors of many pathogens in Europe, where the most impactful species is Ixodes ricinus. Recently, the geographical distribution of this tick species has been expanding, resulting in an increased risk of human exposure to tick bites. With the present study, we aimed to screen 350 I. ricinus specimens collected from humans and wild animals (mainly ungulates), to have a broader understanding of the tick-borne pathogens circulating in the Lombardy region, in northern Italy. To do so, we took advantage of a high-throughput real-time microfluidic PCR approach to screen ticks in a cost-effective and time-saving manner. Molecular analysis of the dataset revealed the presence of four genera of bacteria and two genera of protozoa: in ungulates, 77 % of collected ticks carried Anaplasma phagocytophilum, while the most common pathogen species in ticks removed from humans were those belonging to Borrelia burgdorferi sensu lato group (7.6 %). We also detected other pathogenic microorganisms, such as Rickettisa monacensis, Rickettsia helvetica, Neoehrlichia mikurensis, Babesia venatorum, and Hepatozoon martis. Besides, we also reported the presence of the pathogenic agent Borrelia miyamotoi in the area (1.4 % overall). The most common dual co-infection detected in the same tick individual involved A. phagocytophilum and Rickettsia spp. Our study provided evidence of the circulation of different tick-borne pathogens in a densely populated region in Italy.


Asunto(s)
Babesia , Grupo Borrelia Burgdorferi , Ixodes , Rickettsia , Enfermedades por Picaduras de Garrapatas , Animales , Humanos , Ixodes/microbiología , Ensayos Analíticos de Alto Rendimiento , Animales Salvajes , Italia/epidemiología , Babesia/genética , Grupo Borrelia Burgdorferi/genética , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/veterinaria , Enfermedades por Picaduras de Garrapatas/microbiología
18.
Nat Commun ; 15(1): 1093, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38321113

RESUMEN

The order Rickettsiales (Alphaproteobacteria) encompasses multiple diverse lineages of host-associated bacteria, including pathogens, reproductive manipulators, and mutualists. Here, in order to understand how intracellularity and host association originated in this order, and whether they are ancestral or convergently evolved characteristics, we built a large and phylogenetically-balanced dataset that includes de novo sequenced genomes and a selection of published genomic and metagenomic assemblies. We perform detailed functional reconstructions that clearly indicates "late" and parallel evolution of obligate host-association in different Rickettsiales lineages. According to the depicted scenario, multiple independent horizontal acquisitions of transporters led to the progressive loss of biosynthesis of nucleotides, amino acids and other metabolites, producing distinct conditions of host-dependence. Each clade experienced a different pattern of evolution of the ancestral arsenal of interaction apparatuses, including development of specialised effectors involved in the lineage-specific mechanisms of host cell adhesion and/or invasion.


Asunto(s)
Alphaproteobacteria , Rickettsiales , Rickettsiales/genética , Filogenia , Citoplasma , Alphaproteobacteria/genética , Metagenoma , Evolución Molecular
19.
Health Econ Policy Law ; 18(3): 321-328, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36189782

RESUMEN

Multimorbid patients who enter English NHS hospitals are frequently subject to care pathways designed to assess, diagnose and treat single medical conditions. Opportunities are thereby lost to offer patients more holistic, person-centred care. Hospital organisations elsewhere are known to use in-hospital, multi-specialty, integrated clinical care (ICC) to overcome this problem. This perspective piece aims to critically discuss barriers to implementing this form of ICC in the English NHS focusing on six key areas: information technologies, the primary-secondary care interface, internal hospital processes, finance, workload, professional roles and behaviours. Integrated care programmes currently underway are largely focused on macro (system) and meso (organisational) levels. A micro (clinical) level ICC, offering highly coordinated multispecialty expertise to multimorbid hospital patients could fill an important gap in the current care pathways.


Asunto(s)
Prestación Integrada de Atención de Salud , Medicina Estatal , Humanos , Hospitales
20.
J Parasitol ; 108(2): 209-216, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35435986

RESUMEN

The genus Eustrongylides includes zoonotic nematodes that infect fish species and fish-eating birds of freshwater ecosystems. This study aimed to evaluate the occurrence of Eustrongylides in the paratenic host Perca fluviatilis (European perch) and in the definitive host, Phalacrocorax carbo sinensis (great cormorant), in Lake Annone, a shallow eutrophic lake located in the pre-mountainous area of the Alps in northwest Italy where wintering cormorants coexist with new breeding colonies. A total of 114 European perch and 48 cormorants were examined for the occurrence of Eustrongylides. All parasites collected were identified with microscopic examination and molecular analysis. Overall, 11 specimens of European perch (9.6%) and 13 individuals of cormorants (27%) harbored nematodes identified as fourth-stage larvae and adults of Eustrongylides excisus. The observed prevalence of Eustrongylides spp. appears to be intermediate between the higher values in cormorant breeding areas in northern Europe and the lower prevalence observed in their wintering sites in southernmost Europe. Considering the eutrophication status of freshwater ecosystems and the increasing population of the cormorants, Eustrongylides has an increasing potential range of dispersion in Europe, including Italy; thus an extensive surveillance should be carried out, especially given the zoonotic potential of this nematode.


Asunto(s)
Dioctophymatoidea , Helmintos , Nematodos , Percas , Animales , Aves/parasitología , Ecosistema , Lagos , Percas/parasitología
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