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1.
Int J Mol Sci ; 21(19)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003310

RESUMO

Attributed to the tropism for host microvascular endothelium lining the blood vessels, vascular inflammation and dysfunction represent salient features of rickettsial pathogenesis, yet the details of fundamentally important pathogen interactions with host endothelial cells (ECs) as the primary targets of infection remain poorly appreciated. Mechanistic target of rapamycin (mTOR), a serine/threonine protein kinase of the phosphatidylinositol kinase-related kinase family, assembles into two functionally distinct complexes, namely mTORC1 (Raptor) and mTORC2 (Rictor), implicated in the determination of innate immune responses to intracellular pathogens via transcriptional regulation. In the present study, we investigated activation status of mTOR and its potential contributions to host EC responses during Rickettsia rickettsii and R. conorii infection. Protein lysates from infected ECs were analyzed for threonine 421/serine 424 phosphorylation of p70 S6 kinase (p70 S6K) and that of serine 2448 on mTOR itself as established markers of mTORC1 activation. For mTORC2, we assessed phosphorylation of protein kinase B (PKB or Akt) and protein kinase C (PKC), respectively, on serine 473 and serine 657. The results suggest increased phosphorylation of p70 S6K and mTOR during Rickettsia infection of ECs as early as 3 h and persisting for up to 24 h post-infection. The steady-state levels of phospho-Akt and phospho-PKC were also increased. Infection with pathogenic rickettsiae also resulted in the formation of microtubule-associated protein 1A/1B-light chain 3 (LC3-II) puncta and increased lipidation of LC3-II, a response significantly inhibited by introduction of siRNA targeting mTORC1 into ECs. These findings thus yield first evidence for the activation of both mTORC1 and mTORC2 during EC infection in vitro with Rickettsia species and suggest that early induction of autophagy in response to intracellular infection might be regulated by this important pathway known to function as a central integrator of cellular immunity and inflammation.


Assuntos
Imunidade Inata/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Rickettsiaceae/genética , Rickettsiose do Grupo da Febre Maculosa/genética , Células Endoteliais/microbiologia , Endotélio/metabolismo , Endotélio/microbiologia , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 2 de Rapamicina/genética , Fosforilação/genética , Proteínas Proto-Oncogênicas c-akt/genética , Rickettsiaceae/patogenicidade , Transdução de Sinais , Rickettsiose do Grupo da Febre Maculosa/microbiologia , Rickettsiose do Grupo da Febre Maculosa/patologia , Serina-Treonina Quinases TOR/genética , Transcrição Genética
2.
PLoS Negl Trop Dis ; 14(10): e0008704, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33091016

RESUMO

Over the last decades, rickettsioses are emerging worldwide. These diseases are caused by intracellular bacteria. Although rickettsioses can be treated with antibiotics, a vaccine against rickettsiae is highly desired for several reasons. Rickettsioses are highly prevalent, especially in poor countries, and there are indications of the development of antibiotic resistance. In addition, some rickettsiae can persist and cause recurrent disease. The development of a vaccine requires the understanding of the immune mechanisms that are involved in protection as well as in immunopathology. Knowledge about these immune responses is accumulating, and efforts have been undertaken to identify antigenic components of rickettsiae that may be useful as a vaccine. This review provides an overview on current knowledge of adaptive immunity against rickettsiae, which is essential for defense, rickettsial antigens that have been identified so far, and on vaccination strategies that have been used in animal models of rickettsial infections.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Rickettsia/prevenção & controle , Rickettsiaceae/imunologia , Imunidade Adaptativa , Doenças Transmissíveis Emergentes/prevenção & controle , Humanos , Infecções por Rickettsia/metabolismo
3.
Zoonoses Public Health ; 67(3): 291-299, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31984654

RESUMO

Typhus group rickettsioses (TGRs) are vector-borne diseases that include murine typhus (Rickettsia typhi) and epidemic typhus (R. prowazekii). Twentieth-century public health interventions led to dramatic decreases in incidence; little is known about the contemporary TGR prevalence because neither disease is nationally notifiable. We summarized administrative claims data in a commercially insured population to examine trends in TGR medical encounters. We analysed data from 2003 to 2016 IBM® MarketScan® Commercial Databases to identify persons with inpatient or outpatient visits with an International Classification of Diseases, Ninth or Tenth Revision, Clinical Modification TGR-specific code. We summarized epidemiologic characteristics associated with incident diagnosis. We identified 1,799 patients diagnosed with a TGR. Patients resided in 46 states, and most were female (n = 1,019/1,799; 56.6%); the median age was 42 years (range: 0-64 years). Epidemic typhus (n = 931/1,799; 51.8%) was the most common TGRs, followed by murine typhus (n = 722/1,799; 40.1%). The majority of TGR patients were diagnosed in an outpatient setting (n = 1,725/1,799; 95.9%); among hospitalized patients, the majority received a murine typhus diagnosis (n = 67/74; 90.5%). TGRs are rarely diagnosed diseases. More patients were diagnosed with epidemic than murine typhus, even though R. prowazekii transmission requires body louse or flying squirrel exposure. Patients from all geographic regions were diagnosed with murine and epidemic typhus, despite historically recognized ranges for these diseases. The epidemiologic misalignment of insurance claims data versus historic TGRs data highlights the challenges of finding appropriate alternative data sources to serve as a proxy when national surveillance data do not exist.


Assuntos
Rickettsiaceae/classificação , Tifo Endêmico Transmitido por Pulgas/microbiologia , Tifo Epidêmico Transmitido por Piolhos/epidemiologia , Tifo Epidêmico Transmitido por Piolhos/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Bases de Dados como Assunto , Feminino , Humanos , Lactente , Formulário de Reclamação de Seguro , Seguro Saúde , Masculino , Pessoa de Meia-Idade , Vigilância da População , Fatores de Tempo , Tifo Endêmico Transmitido por Pulgas/epidemiologia , Estados Unidos , Adulto Jovem
4.
Curr Biol ; 30(5): 925-933.e3, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-31978335

RESUMO

Genome evolution in bacterial endosymbionts is notoriously extreme: the combined effects of strong genetic drift and unique selective pressures result in highly reduced genomes with distinctive adaptations to hosts [1-4]. These processes are mostly known from animal endosymbionts, where nutritional endosymbioses represent the best-studied systems. However, eukaryotic microbes, or protists, also harbor diverse bacterial endosymbionts, but their genome reduction and functional relationships with their hosts are largely unexplored [5-7]. We sequenced the genomes of four bacterial endosymbionts from three species of diplonemids, poorly studied but abundant and diverse heterotrophic protists [8-12]. The endosymbionts come from two bacterial families, Rickettsiaceae and Holosporaceae, that have invaded two families of diplonemids, and their genomes have converged on an extremely small size (605-632 kilobase pairs [kbp]), similar gene content (e.g., metabolite transporters and secretion systems), and reduced metabolic potential (e.g., loss of energy metabolism). These characteristics are generally found in both families, but the diplonemid endosymbionts have evolved greater extremes in parallel. They possess modified type VI secretion systems that could function in manipulating host metabolism or other intracellular interactions. Finally, modified cellular machinery like the ATP synthase without oxidative phosphorylation, and the reduced flagellar apparatus present in some diplonemid endosymbionts and nutritional animal endosymbionts, indicates that intracellular mechanisms have converged in bacterial endosymbionts with various functions and from different eukaryotic hosts across the tree of life.


Assuntos
Evolução Molecular , Genoma Bacteriano , Holosporaceae/genética , Rickettsiaceae/genética , Euglenozoários/microbiologia , Simbiose
5.
J Vector Borne Dis ; 56(2): 92-97, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31397383

RESUMO

Background & objectives: Mosquito surveillance is one of the critical functions of local health departments, particularly in the context of outbreaks of severe mosquito-borne viral infections. Unfortunately, some viral and parasitic infections transmitted by mosquitoes, manifests non-specific clinical symptoms which may actually be of rickettsial etiology, including Rickettsia felis infections. This study tested the hypothesis that mosquitoes from southeastern Georgia, USA may be infected with Rickettsia felis and Wolbachia, an endosymbiotic bacterium of the order Rickettsiales. Methods: Specimens of the five most common mosquito species occurring in the region were collected using gravid and light-traps and identified using morphological keys. Mosquitoes were then pooled by species, sex, trap and collection site and their DNA was extracted. Molecular methods were used to confirm mosquito identification, and presence of Wolbachia and R. felis. Results: Wolbachia DNA was detected in 90.8% of the mosquito pools tested, which included 98% pools of Cx. quinquefasciatus Say (Diptera: Culicidae), 95% pools of Ae. albopictus Skuse (Diptera: Culicidae), and 66.7% of pools of Cx. pipiens complex. Samples of An. punctipennis Say (Diptera: Culicidae) and An. crucians Wiedemann (Diptera: Culicidae) were tested negative for Wolbachia DNA. Three genotypes of Wolbachia sp. belonging to Group A (1 type) and Group B (2 types) were identified. DNA of R. felis was not found in any pool of mosquitoes tested. Interpretation & conclusions: This study provides a pilot data on the high presence of Wolbachia in Cx. quinque-fasciatus and Ae. albopictus mosquitoes prevalent in the study region. Whether the high prevalence of Wolbachia and its genetic diversity in mosquitoes affects the mosquitoes' susceptibility to R. felis infection in Georgia will need further evaluation.


Assuntos
Culicidae/microbiologia , Rickettsiaceae/isolamento & purificação , Wolbachia/isolamento & purificação , Animais , DNA Bacteriano/genética , Feminino , Genótipo , Georgia , Masculino , Projetos Piloto , RNA Ribossômico 16S , Rickettsiaceae/genética , Wolbachia/genética
7.
Sci Rep ; 9(1): 1179, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718604

RESUMO

Members of the order Rickettsiales are often found in association with ciliated protists. An interesting case is the bacterial endosymbiont "Candidatus Megaira", which is phylogenetically closely related to the pathogen Rickettsia. "Candidatus Megaira" was first described as an intracellular bacterium in several ciliate species. Since then it has been found in association with diverse evolutionary distantly-related hosts, among them other unicellular eukaryotes, and also algae, and metazoa, such as cnidarians. We provide the characterization of several new strains of the type species "Candidatus Megaira polyxenophila", and the multidisciplinary description of a novel species, "Candidatus Megaira venefica", presenting peculiar features, which highlight the diversity and variability of these widespread bacterial endosymbionts. Screening of the 16S rRNA gene short amplicon database and phylogenetic analysis of 16S rRNA gene hypervariable regions revealed the presence of further hidden lineages, and provided hints on the possibility that these bacteria may be horizontally transmitted among aquatic protists and metazoa. The phylogenetic reconstruction supports the existence of at least five different separate species-level clades of "Candidatus Megaira", and we designed a set of specific probes allowing easy recognition of the four major clades of the genus.


Assuntos
Cilióforos/microbiologia , Variação Genética , Rickettsiaceae/classificação , Rickettsiaceae/isolamento & purificação , Simbiose , Organismos Aquáticos/microbiologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Filogenia , RNA Ribossômico 16S/genética , Rickettsiaceae/genética , Rickettsiaceae/fisiologia , Análise de Sequência de DNA
8.
Genome Biol Evol ; 11(2): 362-379, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30629162

RESUMO

Eustigmatophytes, a class of stramenopile algae (ochrophytes), include not only the extensively studied biotechnologically important genus Nannochloropsis but also a rapidly expanding diversity of lineages with much less well characterized biology. Recent discoveries have led to exciting additions to our knowledge about eustigmatophytes. Some proved to harbor bacterial endosymbionts representing a novel genus, Candidatus Phycorickettsia, and an operon of unclear function (ebo) obtained by horizontal gene transfer from the endosymbiont lineage was found in the plastid genomes of still other eustigmatophytes. To shed more light on the latter event, as well as to generally improve our understanding of the eustigmatophyte evolutionary history, we sequenced plastid genomes of seven phylogenetically diverse representatives (including new isolates representing undescribed taxa). A phylogenomic analysis of plastid genome-encoded proteins resolved the phylogenetic relationships among the main eustigmatophyte lineages and provided a framework for the interpretation of plastid gene gains and losses in the group. The ebo operon gain was inferred to have probably occurred within the order Eustigmatales, after the divergence of the two basalmost lineages (a newly discovered hitherto undescribed strain and the Pseudellipsoidion group). When looking for nuclear genes potentially compensating for plastid gene losses, we noticed a gene for a plastid-targeted acyl carrier protein that was apparently acquired by horizontal gene transfer from Phycorickettsia. The presence of this gene in all eustigmatophytes studied, including representatives of both principal clades (Eustigmatales and Goniochloridales), is a genetic footprint indicating that the eustigmatophyte-Phycorickettsia partnership started no later than in the last eustigmatophyte common ancestor.


Assuntos
Evolução Biológica , Genomas de Plastídeos , Óperon , Rickettsiaceae/genética , Estramenópilas/genética , Sequência de Aminoácidos , Estramenópilas/microbiologia , Simbiose
9.
Ticks Tick Borne Dis ; 9(6): 1606-1613, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30100386

RESUMO

Haemaphysalis longicornis, the cattle tick or bush tick, has an extended distribution throughout Asia and the Pacific region, including China, Russia, the Republic of Korea (ROK), Japan, Australia, New Zealand, and the South Pacific islands. It is an obligate ectoparasite found commonly on medium to large sized wild and domestic animals, with humans as an accidental host. Haemaphysalis longicornis transmits a number of pathogens, including severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses, bacteria, helminths, and protozoans, that impact on veterinary (wild and domestic animals) and human health. Surveys of rickettsial pathogens associated with H. longicornis from China, the ROK, and Japan have resulted in the discovery of more than 35 incompletely characterized molecular isolates of Rickettsia. In response to the increased global threat of tick-borne rickettsial diseases, H. longicornis collected in the ROK and China were assessed in our laboratory and two additional Rickettsia spp. isolates (ROK-HL727 and XinXian HL9) were identified. These agents were fully characterized by multilocus sequence typing using partial gene fragment sequences of rrs, gltA, ompA, ompB, and sca4. Phylogenetic comparisons of these Rickettsia isolates with known Rickettsia species and other molecular isolates identified from H. longicornis were performed to better understand their interrelationships. Phylogenetic analysis of the sequences from these 5 gene fragments showed that ROK-HL727 was closely related to rickettsial isolates of H. longicornis previously reported from China, the ROK and Japan, but distinct from any currently recognized Rickettsia species. It therefore qualifies genetically as a new species, introduced herein as Candidatus Rickettsia longicornii. The XinXian-HL9 isolate detected from China was determined to be genetically similar to the human pathogen Rickettsia heilongjiangensis. People living and working in areas where H. longicornis is endemic should be aware of the potential for rickettsial diseases.


Assuntos
Ixodidae/microbiologia , Rickettsiaceae/isolamento & purificação , Animais , China , Feminino , Genes Bacterianos , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Filogenia , República da Coreia , Rickettsiaceae/classificação , Rickettsiaceae/genética , Análise de Sequência de DNA
10.
Microbiome ; 6(1): 141, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30103809

RESUMO

BACKGROUND: Pathogen colonization inside tick tissues is a significant aspect of the overall competence of a vector. Amblyomma maculatum is a competent vector of the spotted fever group rickettsiae, Rickettsia parkeri. When R. parkeri colonizes its tick host, it has the opportunity to dynamically interact with not just its host but with the endosymbionts living within it, and this enables it to modulate the tick's defenses by regulating tick gene expression. The microbiome in A. maculatum is dominated by two endosymbiont microbes: a Francisella-like endosymbiont (FLE) and Candidatus Midichloria mitochondrii (CMM). A range of selenium-containing proteins (selenoproteins) in A. maculatum ticks protects them from oxidative stress during blood feeding and pathogen infections. Here, we investigated rickettsial multiplication in the presence of tick endosymbionts and characterized the functional significance of selenoproteins during R. parkeri replication in the tick. RESULTS: FLE and CMM were quantified throughout the tick life stages by quantitative PCR in R. parkeri-infected and uninfected ticks. R. parkeri infection was found to decrease the FLE numbers but CMM thrived across the tick life cycle. Our qRT-PCR analysis indicated that the transcripts of genes with functions related to redox (selenogenes) were upregulated in ticks infected with R. parkeri. Three differentially expressed proteins, selenoprotein M, selenoprotein O, and selenoprotein S were silenced to examine their functional significance during rickettsial replication within the tick tissues. Gene silencing of the target genes was found to impair R. parkeri colonization in the tick vector. Knockdown of the selenogenes triggered a compensatory response from other selenogenes, as observed by changes in gene expression, but oxidative stress levels and endoplasmic reticulum stress inside the ticks were also found to have heightened. CONCLUSIONS: This study illustrates the potential of this new research model for augmenting our understanding of the pathogen interactions occurring within tick hosts and the important roles that symbionts and various tick factors play in regulating pathogen growth.


Assuntos
Rickettsia/crescimento & desenvolvimento , Rickettsiaceae/fisiologia , Selenoproteínas/genética , Carrapatos/microbiologia , Animais , Vetores Aracnídeos/genética , Vetores Aracnídeos/metabolismo , Vetores Aracnídeos/microbiologia , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Feminino , Regulação Bacteriana da Expressão Gênica , Inativação Gênica , Golfo do México , Masculino , Estresse Oxidativo , Selenoproteínas/metabolismo , Simbiose , Carrapatos/genética , Carrapatos/metabolismo , Regulação para Cima
11.
Korean J Parasitol ; 56(3): 305-308, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29996637

RESUMO

This study was aimed to disclose the prevalence rate of tick-borne pathogens from ticks collected from cattle and wild animals in Tanzania in 2012. Ticks were collected from slaughtered cattle and dead wild animals from November 5 to December 23, 2012 and identified. PCR for detecting Anaplasmataceae, Piroplamidae, Rickettsiaceae, Borrelia spp., and Coxiella spp. were done. Among those tested, Rickettsiaceae, Piroplasmidae, and Anaplasmataceae, were detected in ticks from the 2 regions. Rickettsiaceae represented the major tick-borne pathogens of the 2 regions. Ticks from animals in Maswa were associated with a higher pathogen detection rate compared to that in ticks from Iringa. In addition, a higher pathogen detection rate was observed in ticks infesting cattle than in ticks infesting wild animals. All examined ticks of the genus Amblyomma were infected with diverse pathogens. Ticks of the genera Rhipicephalus and Hyalomma were infected with 1 or 2 pathogens. Collectively, this study provides important information regarding differences in pathogen status among various regions, hosts, and tick species in Tanzania. Results in this study will affect the programs to prevent tick-borne diseases (TBD) of humans and livestock in Tanzania.


Assuntos
Anaplasma/patogenicidade , Animais Selvagens/parasitologia , Borrelia/patogenicidade , Doenças dos Bovinos/etiologia , Bovinos/parasitologia , Coxiella/patogenicidade , Piroplasmida/patogenicidade , Rickettsiaceae/patogenicidade , Doenças Transmitidas por Carrapatos/etiologia , Doenças Transmitidas por Carrapatos/veterinária , Carrapatos/microbiologia , Carrapatos/parasitologia , Anaplasma/isolamento & purificação , Animais , Borrelia/isolamento & purificação , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Coxiella/isolamento & purificação , Piroplasmida/isolamento & purificação , Prevalência , Rickettsiaceae/isolamento & purificação , Tanzânia/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/parasitologia , Fatores de Tempo
12.
ISME J ; 12(9): 2163-2175, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29880910

RESUMO

Rickettsiales are obligate intracellular bacteria originally found in metazoans, but more recently recognized as widespread endosymbionts of various protists. One genus was detected also in several green algae, but reports on rickettsialean endosymbionts in other algal groups are lacking. Here we show that several distantly related eustigmatophytes (coccoid algae belonging to Ochrophyta, Stramenopiles) are infected by Candidatus Phycorickettsia gen. nov., a new member of the family Rickettsiaceae. The genome sequence of Ca. Phycorickettsia trachydisci sp. nov., an endosymbiont of Trachydiscus minutus CCALA 838, revealed genomic features (size, GC content, number of genes) typical for other Rickettsiales, but some unusual aspects of the gene content were noted. Specifically, Phycorickettsia lacks genes for several components of the respiration chain, haem biosynthesis pathway, or c-di-GMP-based signalling. On the other hand, it uniquely harbours a six-gene operon of enigmatic function that we recently reported from plastid genomes of two distantly related eustigmatophytes and from various non-rickettsialean bacteria. Strikingly, the eustigmatophyte operon is closely related to the one from Phycorickettsia, suggesting a gene transfer event between the endosymbiont and host lineages in early eustigmatophyte evolution. We hypothesize an important role of the operon in the physiology of Phycorickettsia infection and a long-term eustigmatophyte-Phycorickettsia coexistence.


Assuntos
Transferência Genética Horizontal , Rickettsiaceae/genética , Estramenópilas/microbiologia , Genômica , Óperon , Simbiose
13.
BMC Vet Res ; 14(1): 98, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29554900

RESUMO

BACKGROUND: Hunting constitutes an important industry in Europe. However, data on the prevalence of vector-borne bacteria in large game animal species are lacking from several countries. Blood or spleen samples (239 and 270, respectively) were taken from red, fallow and roe deer, as well as from water buffaloes, mouflons and wild boars in Hungary, followed by DNA extraction and molecular analyses for Anaplasma phagocytophilum, haemoplasmas and rickettsiae. RESULTS: Based on blood samples, the prevalence rate of A. phagocytophilum infection was significantly higher in red deer (97.9%) than in fallow deer (72.7%) and roe deer (60%), and in all these compared to mouflons (6.3%). In addition, 39.2% of the spleen samples from wild boars were PCR positive for A. phagocytophilum, but none of the buffalos. Based on blood samples, the prevalence rates of both Mycoplasma wenyonii (Mw) and 'Candidatus M. haemobos' (CMh) infections were significantly higher in buffaloes (Mw: 91.2%; CMh: 73.3%) than in red deer (Mw: 64.6%; CMh: 45.8%), and in both of them compared to fallow deer (Mw: 30.3%; CMh: 9.1%) and roe deer (Mw: 20%; CMh: 1.5%). The prevalence of Mw and CMh infection significantly correlated with the body sizes of these hosts. Furthermore, Mw was significantly more prevalent than CMh in buffaloes, red and roe deer. Mycoplasma ovis was detected in mouflons, M. suis in wild boars, R. helvetica in one fallow deer and one mouflon, and an unidentified Rickettsia sp. in a fallow deer. CONCLUSIONS: Forest-dwelling game animal species were found to be important carriers of A. phagocytophilum. In contrast, animals grazing grassland (i.e. buffaloes) were less likely to get infected with this Ixodes ricinus-borne pathogen. Water buffaloes, deer species, mouflons and wild boars harbored haemoplasmas that may affect domestic ungulates. Evaluated animals with larger body size had significantly higher prevalence of infection with haemoplasmas compared to smaller deer species. The above host species rarely carried rickettsiae.


Assuntos
Anaplasma phagocytophilum , Búfalos/microbiologia , Cervos/microbiologia , Ehrlichiose/veterinária , Infecções por Mycoplasma/veterinária , Mycoplasma , Infecções por Rickettsiaceae/veterinária , Rickettsiaceae , Animais , Animais Selvagens/microbiologia , Vetores Aracnídeos/microbiologia , Dípteros/microbiologia , Ehrlichiose/epidemiologia , Ehrlichiose/microbiologia , Hungria/epidemiologia , Insetos Vetores/microbiologia , Masculino , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/microbiologia , Prevalência , Infecções por Rickettsiaceae/epidemiologia , Infecções por Rickettsiaceae/microbiologia , Carrapatos/microbiologia
14.
Sci Rep ; 8(1): 2491, 2018 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-29410494

RESUMO

Springtails are important members of the soil fauna and play a key role in plant litter decomposition, for example through stimulation of the microbial activity. However, their interaction with soil microorganisms remains poorly understood and it is unclear which microorganisms are associated to the springtail (endo) microbiota. Therefore, we assessed the structure of the microbiota of the springtail Orchesella cincta (L.) using 16S rRNA gene amplicon sequencing. Individuals were sampled across sites in the field and the microbiota and in particular the endomicrobiota were investigated. The microbiota was dominated by the families of Rickettsiaceae, Enterobacteriaceae and Comamonadaceae and at the genus level the most abundant genera included Rickettsia, Chryseobacterium, Pseudomonas, and Stenotrophomonas. Microbial communities were distinct for the interior of the springtails for measures of community diversity and exhibited structure according to collection sites. Functional analysis of the springtail bacterial community suggests that abundant members of the microbiota may be associated with metabolism including decomposition processes. Together these results add to the understanding of the microbiota of springtails and interaction with soil microorganisms including their putative functional roles.


Assuntos
Artrópodes/microbiologia , Chryseobacterium/genética , Comamonadaceae/genética , Enterobacteriaceae/genética , Pseudomonas/genética , Rickettsiaceae/genética , Stenotrophomonas/genética , Animais , Biodiversidade , Chryseobacterium/classificação , Chryseobacterium/isolamento & purificação , Chryseobacterium/metabolismo , Comamonadaceae/classificação , Comamonadaceae/isolamento & purificação , Comamonadaceae/metabolismo , DNA Bacteriano/genética , Enterobacteriaceae/classificação , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/metabolismo , Microbiota/genética , Pseudomonas/classificação , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RNA Ribossômico 16S/genética , Rickettsiaceae/classificação , Rickettsiaceae/isolamento & purificação , Rickettsiaceae/metabolismo , Análise de Sequência de DNA , Microbiologia do Solo , Stenotrophomonas/classificação , Stenotrophomonas/isolamento & purificação , Stenotrophomonas/metabolismo
16.
Mol Microbiol ; 105(3): 440-452, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28513097

RESUMO

Bacterial cell walls are composed of the large cross-linked macromolecule peptidoglycan, which maintains cell shape and is responsible for resisting osmotic stresses. This is a highly conserved structure and the target of numerous antibiotics. Obligate intracellular bacteria are an unusual group of organisms that have evolved to replicate exclusively within the cytoplasm or vacuole of a eukaryotic cell. They tend to have reduced amounts of peptidoglycan, likely due to the fact that their growth and division takes place within an osmotically protected environment, and also due to a drive to reduce activation of the host immune response. Of the two major groups of obligate intracellular bacteria, the cell wall has been much more extensively studied in the Chlamydiales than the Rickettsiales. Here, we present the first detailed analysis of the cell envelope of an important but neglected member of the Rickettsiales, Orientia tsutsugamushi. This bacterium was previously reported to completely lack peptidoglycan, but here we present evidence supporting the existence of a peptidoglycan-like structure in Orientia, as well as an outer membrane containing a network of cross-linked proteins, which together confer cell envelope stability. We find striking similarities to the unrelated Chlamydiales, suggesting convergent adaptation to an obligate intracellular lifestyle.


Assuntos
Orientia tsutsugamushi/metabolismo , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Orientia tsutsugamushi/química , Orientia tsutsugamushi/genética , Peptidoglicano/metabolismo , Rickettsiaceae/metabolismo
17.
Ticks Tick Borne Dis ; 8(4): 574-580, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28411028

RESUMO

Rickettsiales bacteria are important agents of (re)emerging infectious diseases, with ticks playing a key role in their evolution and transmission. We collected 1079 hard ticks belonging to five species (Ixodes sinensis, Rhipicephalus microplus, Haemaphysalis flava, Haemaphysalis hystricis and Haemaphysalis longicornis) from cattle and goats in Wuhan city, Hubei province, China. The dominant tick species was H. longicornis (578, 53.57%), followed by R. microplus (354, 32.81%), H. hystricis (62, 5.75%), H. flava (57, 5.28%), and I. sinensis (28, 2.59%). Rickettsiales bacteria were identified in these ticks by amplifying the Rickettsiales 16S rRNA (rrs), citrate synthase (gltA), and heat shock protein (groEL) genes. The rrs gene of Rickettsiales was positive in 32 (2.97%) ticks, including 2 cases of co-infection, with 4 (0.69%) in H. longicornis, 15 (4.24%) in R. microplus, 7 (12.28%) in H. flava, 1 (1.61%) in H. hystricis, and 5 (17.86%) in I. sinensis ticks. Phylogenetic analysis revealed the presence of six recognized and seven Candidatus species of Rickettsiaceae, Anaplasmataceae and Candidatus Midichloriaceae. Notably, one lineage within both Ehrlichia and Candidatus Midichloriaceae was distinct from any known Rickettsiales, suggesting the presence of potentially novel species of Rickettsiales bacteria. In sum, these data reveal an extensive diversity of Rickettsiales in ticks from Wuhan, highlighting the need to understand Rickettsiales infection in local animals and humans.


Assuntos
Anaplasmataceae/classificação , Ixodidae/microbiologia , Rickettsiaceae/classificação , Alphaproteobacteria/classificação , Alphaproteobacteria/enzimologia , Alphaproteobacteria/genética , Alphaproteobacteria/isolamento & purificação , Anaplasmataceae/enzimologia , Anaplasmataceae/genética , Anaplasmataceae/isolamento & purificação , Animais , Proteínas de Bactérias/genética , Bovinos/parasitologia , China , Cabras/parasitologia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Rickettsiaceae/enzimologia , Rickettsiaceae/genética , Rickettsiaceae/isolamento & purificação
18.
Parasit Vectors ; 10(1): 61, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28153052

RESUMO

BACKGROUND: Little is known regarding tick-borne diseases in Mongolia, despite having 26% of the population still living nomadic pastoral lifestyles. A total of 1497 adult unfed ticks: 261 Ixodes persulcatus, 795 Dermacentor nuttalli, and 441 Hyalomma asiaticum, were collected from three ecologically distinct regions in Central Mongolia. Tick pools (n = 299) containing ~5 ticks each, were tested for Rickettsia and Tick-borne encephalitis virus (TBEV) using nested polymerase chain reaction, reverse transcription-PCR, and quantitative real-time RT-PCR. RESULTS: Assays yielded pooled prevalence of 92.5% (49/53) and 1.9% (1/53) for pooled I. persulcatus testing positive for "Candidatus Rickettsia tarasevichiae" and TBEV, respectively, while Rickettsia raoultii was found in 72.8% (115/158) of pooled D. nuttalli samples. When calculating a maximum likelihood estimation, an estimated 46.6% (95% CI: 35.2-63.6%) of I. persulcatus ticks in the pooled sample were infected with "Candidatus R. tarasevichiae". CONCLUSIONS: Both "Candidatus R. tarasevichiae" and R. raoultii are recognized as emerging tick-borne pathogens, with this being one of the first reports of "Candidatus R. tarasevichiae" in Mongolia. Given that "Candidatus R. tarasevichiae" shares the same vector (I. persulcatus) as TBEV, and infections may present with similar symptoms, Mongolian physicians treating suspected cases of TBEV should include "Candidatus R. tarasevichiae" infection in their differential diagnosis and consider prescribing antimicrobial therapy.


Assuntos
Ixodidae/microbiologia , Rickettsiaceae/classificação , Rickettsiaceae/isolamento & purificação , Animais , Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Ixodidae/classificação , Ixodidae/virologia , Mongólia , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rickettsiaceae/genética
19.
Appl Environ Microbiol ; 82(24): 7236-7247, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27742680

RESUMO

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.


Assuntos
Alphaproteobacteria/isolamento & purificação , Citoplasma/microbiologia , Paramecium/microbiologia , Rickettsiaceae/isolamento & purificação , Alphaproteobacteria/classificação , Alphaproteobacteria/genética , Alphaproteobacteria/fisiologia , Paramecium/fisiologia , Filogenia , Rickettsiaceae/classificação , Rickettsiaceae/genética , Rickettsiaceae/fisiologia , Simbiose
20.
Schweiz Arch Tierheilkd ; 158(10): 691-700, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27707682

RESUMO

INTRODUCTION: 'Candidatus Neoehrlichia mikurensis' is an emerging tick-borne zoonotic agent that primarily affects immunocompromised human patients. Dogs and foxes are frequently exposed to ticks, and both species are in close proximity to humans. This is the first study to systematically investigate the occurrence of 'Candidatus Neoehrlichia mikurensis' in Canidae in Europa. We analyzed 1'739 blood samples from dogs in Switzerland, Italy, Spain and Portugal and 162 blood samples from free-ranging red foxes (Vulpes vulpes) in Switzerland. All samples were tested using a previously described multiplex real-time PCR for the Anaplasmataceae family, the 'Candidatus Neoehrlichia' genus and the 'Candidatus Neoehrlichia mikurensis' species. All Anaplasmataceae positive samples were subsequently tested using specific real-time PCRs for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis and Rickettsia helvetica. Among the tested animals, one dog from Zurich tested positive for 'Candidatus Neoehrlichia mikurensis'. The 12-year old West Highland white terrier had been splenectomized 3 months prior to the blood collection and presented with polyuria/polydipsia. Fanconi syndrome was diagnosed based on glucosuria with normoglycemia and hyperaminoaciduria. A. platys and E. canis were detected in 14/249 dogs from Sicily and Portugal; two of the dogs were coinfected with both agents. Four Swiss foxes tested positive for A. phagocytophilium. R. helvetica was detected for the first time in a red fox. In conclusion, 'Candidatus Neoehrlichia mikurensis' infection should be considered in sick dogs, particularly when immunocompromised. The pathogen seems not to be widespread in Canidae in the investigated countries. Conversely, other Anaplasmataceae were more readily detected in dogs and foxes.


Assuntos
Infecções por Anaplasmataceae/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Infecções por Rickettsiaceae/veterinária , Zoonoses/diagnóstico , Zoonoses/epidemiologia , Anaplasmataceae/isolamento & purificação , Infecções por Anaplasmataceae/diagnóstico , Infecções por Anaplasmataceae/epidemiologia , Infecções por Anaplasmataceae/microbiologia , Animais , Coinfecção , Doenças do Cão/microbiologia , Cães , Raposas/microbiologia , Genes Bacterianos/genética , Região do Mediterrâneo , Reação em Cadeia da Polimerase/veterinária , Prevalência , Rickettsiaceae/isolamento & purificação , Infecções por Rickettsiaceae/epidemiologia , Infecções por Rickettsiaceae/microbiologia , Suíça , Zoonoses/microbiologia
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