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1.
Nat Commun ; 15(1): 1093, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321113

RESUMO

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.


Assuntos
Alphaproteobacteria , Rickettsiales , Rickettsiales/genética , Filogenia , Citoplasma , Alphaproteobacteria/genética , Metagenoma , Evolução Molecular
2.
Environ Microbiol ; 26(1): e16562, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38173299

RESUMO

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.


Assuntos
Alphaproteobacteria , Paramecium , Humanos , Alphaproteobacteria/genética , Filogenia , Genômica , Paramecium/microbiologia , Eucariotos/genética , Simbiose/genética
3.
J Health Polit Policy Law ; 49(1): 133-162, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-37522380

RESUMO

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.


Assuntos
COVID-19 , Vacinas , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias , Vacinação , Política de Saúde
4.
Ticks Tick Borne Dis ; 15(1): 102285, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38035456

RESUMO

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.


Assuntos
Babesia , Grupo Borrelia Burgdorferi , Ixodes , Rickettsia , Doenças Transmitidas por Carrapatos , Animais , Humanos , Ixodes/microbiologia , Ensaios de Triagem em Larga Escala , Animais Selvagens , Itália/epidemiologia , Babesia/genética , Grupo Borrelia Burgdorferi/genética , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária , Doenças Transmitidas por Carrapatos/microbiologia
5.
Int Microbiol ; 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37615902

RESUMO

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.

6.
Environ Microbiol ; 25(11): 2102-2117, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37305924

RESUMO

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.


Assuntos
Ixodes , Animais , Ixodes/microbiologia , Bactérias/genética , Mitocôndrias/genética , Filogenia , Simbiose
7.
Parasitol Res ; 122(3): 881-887, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36640182

RESUMO

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.


Assuntos
Cervos , Infecções por Dictyocaulus , Nematoides , Animais , Dictyocaulus/genética , Animais Selvagens/parasitologia , Cervos/parasitologia , Infecções por Dictyocaulus/epidemiologia , Infecções por Dictyocaulus/parasitologia
8.
Health Econ Policy Law ; 18(3): 321-328, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36189782

RESUMO

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.


Assuntos
Prestação Integrada de Cuidados de Saúde , Medicina Estatal , Humanos , Hospitais
9.
Microorganisms ; 10(5)2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35630417

RESUMO

Paramecium (Ciliophora) systematics is well studied, and about twenty morphological species have been described. The morphological species may include several genetic species. However, molecular phylogenetic analyses revealed that the species diversity within Paramecium could be even higher and has raised a problem of cryptic species whose statuses remain uncertain. In the present study, we provide the morphological and molecular characterization of two novel Paramecium species. While Paramecium lynni n. sp., although morphologically similar to P. multimicronucleatum, is phylogenetically well separated from all other Paramecium species, Paramecium fokini n. sp. appears to be a cryptic sister species to P. multimicronucleatum. The latter two species can be distinguished only by molecular methods. The number and structure of micronuclei, traditionally utilized to discriminate species in Paramecium, vary not only between but also within each of the three studied species and, thus, cannot be considered a reliable feature for species identification. The geographic distribution of the P. multimicronucleatum and P. fokini n. sp. strains do not show defined patterns, still leaving space for a role of the geographic factor in initial speciation in Paramecium. Future findings of new Paramecium species can be predicted from the molecular data, while morphological characteristics appear to be unstable and overlapping at least in some species.

10.
J Parasitol ; 108(2): 209-216, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35435986

RESUMO

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.


Assuntos
Dioctophymatoidea , Helmintos , Nematoides , Percas , Animais , Aves/parasitologia , Ecossistema , Lagos , Percas/parasitologia
11.
Microb Drug Resist ; 28(4): 408-412, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35349384

RESUMO

Pantoea spp. are bacteria that are often detected in the environment and as symbionts of arthropods. They sporadically cause infections in humans and recently extended spectrum beta-lactamases (ESBL)- and carbapenemase-producing strains have started to emerge. In this study, we report the isolation and the complete genome sequence of a strain of Pantoea calida encoding the colistin-resistance gene mcr-9. The strain was isolated from a preterm newborn in a neonatal pathology ward. On clinical examination, his vital signs were normal and blood culture was negative. Rectal swab screening for ESBL-producing Enterobacterales allowed to isolate the bacterium, and a complete genome was obtained using both short and long read sequencing. The mcr-9 gene was found to be encoded on a IncHI2 superplasmid, which confers resistance to six classes of antibiotics, including beta lactams (ESBL). Despite the presence of mcr-9, the isolate retains susceptibility to colistin, which could be explained by the absence of compatible regulatory genes (qseBC) from the genome. The presence of the resistance gene is undetectable with the routine clinical procedures, that is, phenotypic tests. This suggests that a silent spread might be ongoing in the ward. To our knowledge, this is the first description of an MDR P. calida and of a Pantoea spp. encoding any mobile colistin resistance gene.


Assuntos
Colistina , Gammaproteobacteria , Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Gammaproteobacteria/efeitos dos fármacos , Gammaproteobacteria/genética , Humanos , Recém-Nascido , Plasmídeos/genética , Fatores R , beta-Lactamases/genética
12.
Vet Parasitol Reg Stud Reports ; 27: 100674, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35012731

RESUMO

Contracaecum rudolphii (s.l.) is a complex of sibling species with different genetic structure and ecological preference. This study reports the presence of specimens of Contracaecum rudolphii (s.l.) from sedentary and wintering cormorants (Phalacrocorax carbo sinensis) from the pre-mountain area of the Alps in Northern Italy, an important crossroads for most of the bird migration routes. A total of 48 specimens of cormorants collected from two adjacent freshwater habitats were analysed and C. rudolphii nematodes were retrieved in 100% of the examined specimens. A subsamples of 115 C. rudolphii individuals were genetically characterized and found to belong to the sibling species C. rudolphii B (n = 90) and C. rudolphii A (n = 25). C. rudolphii B were retrieved from both locations and included adults as well as larvae, while only adults of C. rudolphii A were detected, and in just one location. As expected for a freshwater environment, C. rudolphii B constitutes the largest sibling fraction, indicating that this likely is the endemic species, while cormorants originating from the breeding brackish lagoons and marine coastal environments of central and northern Europe could have brought C. rudolphii A from their breeding sites or migration stopovers.


Assuntos
Ascaridoidea , Doenças das Aves , Animais , Ascaridoidea/genética , Doenças das Aves/epidemiologia , Aves , Ecossistema , Água Doce
13.
Environ Microbiol Rep ; 14(1): 34-49, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34766443

RESUMO

Holosporales are an alphaproteobacterial lineage encompassing bacteria obligatorily associated with multiple diverse eukaryotes. For most representatives, little is known on the interactions with their hosts. In this study, we characterized a novel Holosporales symbiont of the ciliate Paramecium polycaryum. This bacterium inhabits the host cytoplasm, frequently forming quite large aggregates. Possibly due to such aggregates, host cells sometimes displayed lethal division defects. The symbiont was also able to experimentally stably infect another Paramecium polycaryum strain. The bacterium is phylogenetically related with symbionts of other ciliates and diplonemids, forming a putatively fast-evolving clade within the family Holosporaceae. Similarly to many close relatives, it presents a very small genome (<600 kbp), and, accordingly, a limited predicted metabolism, implying a heavy dependence on Paramecium, thanks also to some specialized membrane transporters. Characterized features, including the presence of specific secretion systems, are overall suggestive of a mild parasitic effect on the host. From an evolutionary perspective, a potential ancestral trend towards pronounced genome reduction and possibly linked to parasitism could be inferred, at least among fast-evolving Holosporaceae, with some lineage-specific traits. Interestingly, similar convergent features could be observed in other host-associated lineages, in particular Rickettsiales among Alphaproteobacteria.


Assuntos
Holosporaceae , Paramecium , Parasitos , Animais , Holosporaceae/genética , Paramecium/genética , Paramecium/microbiologia , Filogenia , RNA Ribossômico 16S/genética , Simbiose
14.
Health Econ Policy Law ; 17(1): 1-13, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33663622

RESUMO

On 31st January 2020, the Italian cabinet declared a 6-month national emergency after the detection of the first two COVID-19 positive cases in Rome, two Chinese tourists travelling from Wuhan. Between then and the total lockdown introduced on 22nd March 2020 Italy was hit by an unprecedented crisis. In addition to being the first European country to be heavily swept by the COVID-19 pandemic, Italy was the first to introduce stringent lockdown measures. The SARS-CoV-2 outbreak and related COVID-19 pandemic have been the worst public health challenge endured in recent history by Italy. Two months since the beginning of the first wave, the estimated excess deaths in Lombardy, the hardest hit region in the country, reached a peak of more than 23,000 deaths. The extraordinary pressures exerted on the Italian Servizio Sanitario Nazionale (SSN) inevitably leads to questions about its preparedness and the appropriateness and effectiveness of responses implemented at both national and regional levels. The aim of the paper is to critically review the Italian response to the COVID-19 crisis spanning from the first early acute phases of the emergency (March-May 2020) to the relative stability of the epidemiological situation just before the second outbreak in October 2020.


Assuntos
COVID-19 , Controle de Doenças Transmissíveis , Humanos , Itália/epidemiologia , Pandemias , SARS-CoV-2
15.
Glob Public Health ; 17(5): 768-781, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33487104

RESUMO

While mobile phones promise to be an important tool for bridging the healthcare gaps in resource-poor areas in developing countries, scalability and sustainability of mobile phones for health (mhealth) interventions still remain a major challenge. Meanwhile, health workers are already using their own mobile phones (referred to as 'informal mhealth') to facilitate healthcare delivery in diverse ways. Therefore, this paper explores some strategies for integrating 'informal mHealth' in the healthcare delivery of Ghana, by highlighting some opportunities and challenges. The study mainly employed a combination of literature review, focus group discussions and key informant interviews with community health nurses (CHNs) and other stakeholders, who were purposively selected from the three ecological zones in Ghana. The study found that, while scale-up of 'formal mhealth' remains challenging in Ghana, almost all CHNs in our study are using their personal mobile phones 'informally' to bridge healthcare gaps, thereby promoting universal health coverage. This provides opportunities for promoting (or formalising) 'informal' mhealth in Ghana, in spite of some practical challenges in the use of personal mobile phones that need to be addressed to ensure sustainable healthcare delivery in the country.


Assuntos
Telefone Celular , Telemedicina , Atenção à Saúde , Gana , Humanos , Cobertura Universal do Seguro de Saúde
16.
Health Policy ; 125(9): 1179-1187, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34366171

RESUMO

The paper discusses the responses to the COVID-19 crisis in the acute phase of the first wave of the pandemic (February-May 2020) by different Italian regions in Italy, which has a decentralised healthcare system. We consider five regions (Lombardy, Veneto, Emilia-Romagna, Umbria, Apulia) which are located in the north, centre and south of Italy. These five regions differ both in their healthcare systems and in the extent to which they were hit by the first wave of COVID-19 pandemic. We investigate their different responses to COVID-19 reflecting on seven management factors: (1) monitoring, (2) learning, (3) decision-making, (4) coordinating, (5) communicating, (6) leading, and (7) recovering capacity. In light of these factors, we discuss the analogies and differences among the regions and their different institutional choices.


Assuntos
COVID-19 , Pandemias , Atenção à Saúde , Humanos , Itália , SARS-CoV-2
17.
World Dev ; 140: 105257, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33814676

RESUMO

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.

18.
Front Microbiol ; 12: 624014, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679643

RESUMO

Bacterial species able to produce proteins that are toxic against insects have been discovered at the beginning of the last century. However, up to date only two of them have been used as pesticides in mosquito control strategies targeting larval breeding sites: Bacillus thuringensis var. israelensis and Lysinibacillus sphaericus. Aiming to expand the arsenal of biopesticides, bacterial cultures from 44 soil samples were assayed for their ability to kill larvae of Aedes albopictus. A method to select, grow and test the larvicidal capability of spore-forming bacteria from each soil sample was developed. This allowed identifying 13 soil samples containing strains capable of killing Ae. albopictus larvae. Among the active isolates, one strain with high toxicity was identified as Brevibacillus laterosporus by 16S rRNA gene sequencing and by morphological characterization using transmission electron microscopy. The new isolate showed a larvicidal activity significantly higher than the B. laterosporus LMG 15441 reference strain. Its genome was phylogenomically characterized and compared to the available Brevibacillus genomes. Thus, the new isolate can be considered as a candidate adjuvant to biopesticides formulations that would help preventing the insurgence of resistance.

19.
Exp Appl Acarol ; 83(3): 427-448, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33646482

RESUMO

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.


Assuntos
Rickettsia , Doenças Transmitidas por Carrapatos , África , Animais , Animais Domésticos , Animais Selvagens , Egito/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/veterinária
20.
G3 (Bethesda) ; 11(2)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33615377

RESUMO

During a citywide microbiological screening project in Pavia (Italy) a bacterial strain isolated from the surface of an Automated Teller Machine was classified as a Klebsiella sp. by MALDI-TOF spectrometry, and shown to be susceptible to the most antimicrobial classes by phenotypic testing. After Illumina genome sequencing and subsequent assembly, a high-quality draft genome was obtained (size = 5,051,593 bp, N50 = 615,571 bp, largest contig = 1,328,029 bp, N_contig = 17, GC content = 51.58%, coverage = 141.42), absence of antimicrobial resistance genes was confirmed, but the strain resulted to be highly divergent from all Klebsiella, and more related to other Enterobacteriaceae. The higher values of 16S rRNA identity were with members of the genera Citrobacter, Salmonella, and "Superficieibacter." An ortholog-based phylogenomic analysis indicated a sister group relationship with "Superficieibacter electus," in a distinct clade from other members of the Enterobacteriaceae family. In order to evaluate whether the novel genome represents a new species of "Superficiebacter," average nucleotide identity (ANI) and Hadamard analysis were performed on a dataset of 78 Enterobacteriaceae. The novel genome showed an ANI of 87.51% with S. electus, which compared on identity values between other members of the family, clearly indicates that the genome represents a new species within the genus "Superficieibacter." We propose for the new species the name "Superficieibacter maynardsmithii."


Assuntos
Antibacterianos , Ácidos Graxos , Técnicas de Tipagem Bacteriana , DNA Bacteriano , Enterobacteriaceae/genética , Itália , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA
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