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1.
J Invertebr Pathol ; 190: 107737, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35247466

RESUMO

Bacterial pathogens are a long-standing threat to the longevity and survival of crustacean hosts. Their presence and continuing emergence require close monitoring to understand their impact on fished, cultured, and wild crustacean populations. We describe a new bacterial pathogen belonging to the Anaplasmataceae family (Alphaproteobacteria: Rickettsiales), providing pathological, ultrastructural, phylogenetic, and genomic evidence to determine a candidate genus and species ('Candidatus Mellornella promiscua'). This bacterium was found to infect the mud crab, Eurypanopeus depressus, on the North Carolina coastline (USA) at a prevalence of 10.8%. 'Candidatus Mellornella promiscua' was often observed in co-infection with the rhizocephalan barnacle, Loxothylacus panopaei. The bacterium was only found in the hepatopancreas of the mud crab host, causing cytoplasmic hypertrophy, tubule necrosis, large plaques within the cytoplasm of the host cell, and an abundance of sex-pili. The circular genome of the bacterium is 1,013,119 bp and encodes 939 genes in total. Phylogenetically, the new bacterium branches within the Anaplasmataceae. The genome is dissimilar from other described bacteria, with 16S gene similarity observed at a maximum of 85.3% to a Wolbachia endosymbiont. We explore this novel bacterial pathogen using genomic, phylogenetic, ultrastructural, and pathological methods, discussing these results in light of current bacterial taxonomy, similarity to other bacterial pathogens, and the potential impact upon the surrounding disease ecology of the host and benthic ecosystem.


Assuntos
Alphaproteobacteria , Anaplasmataceae , Braquiúros , Alphaproteobacteria/genética , Anaplasmataceae/genética , Animais , Braquiúros/genética , Ecossistema , Filogenia , RNA Ribossômico 16S/genética , Rickettsiales/genética
2.
Appl Environ Microbiol ; 88(6): e0243221, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35108076

RESUMO

The family "Candidatus Midichloriaceae" constitutes the most diverse but least studied lineage within the important order of intracellular bacteria Rickettsiales. "Candidatus Midichloriaceae" endosymbionts are found in many hosts, including terrestrial arthropods, aquatic invertebrates, and protists. Representatives of the family are not documented to be pathogenic, but some are associated with diseased fish or corals. Different genera display a range of unusual features, such as full sets of flagellar genes without visible flagella or the ability to invade host mitochondria. Since studies on "Ca. Midichloriaceae" tend to focus on the host, the family is rarely addressed as a unit, and we therefore lack a coherent picture of its diversity. Here, we provide four new midichloriaceae genomes, and we survey molecular and ecological data from the entire family. Features like genome size, ecological context, and host transitions vary considerably even among closely related midichloriaceae, suggesting a high frequency of such shifts, incomplete sampling, or both. Important functional traits involved in energy metabolism, flagella, and secretion systems were independently reduced multiple times with no obvious correspondence to host or habitat, corroborating the idea that many features of these "professional symbionts" are largely independent of host identity. Finally, despite "Ca. Midichloriaceae" being predominantly studied in ticks, our analyses show that the clade is mainly aquatic, with a few terrestrial offshoots. This highlights the importance of considering aquatic hosts, and protists in particular, when reconstructing the evolution of these endosymbionts and by extension all Rickettsiales. IMPORTANCE Among endosymbiotic bacterial lineages, few are as intensely studied as Rickettsiales, which include the causative agents of spotted fever, typhus, and anaplasmosis. However, an important subgroup called "Candidatus Midichloriaceae" receives little attention despite accounting for a third of the diversity of Rickettsiales and harboring a wide range of bacteria with unique features, like the ability to infect mitochondria. Midichloriaceae are found in many hosts, from ticks to corals to unicellular protozoa, and studies on them tend to focus on the host groups. Here, for the first time since the establishment of this clade, we address the genomics, evolution, and ecology of "Ca. Midichloriaceae" as a whole, highlighting trends and patterns, the remaining gaps in our knowledge, and its importance for the understanding of symbiotic processes in intracellular bacteria.


Assuntos
Alphaproteobacteria , Rickettsiales , Alphaproteobacteria/genética , Animais , Bactérias , Filogenia , Simbiose
3.
ISME J ; 16(2): 400-411, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34363004

RESUMO

The symbiont "Candidatus Aquarickettsia rohweri" infects a diversity of aquatic hosts. In the threatened Caribbean coral, Acropora cervicornis, Aquarickettsia proliferates in response to increased nutrient exposure, resulting in suppressed growth and increased disease susceptibility and mortality of coral. This study evaluated the extent, as well as the ecology and evolution of Aquarickettsia infecting threatened corals, Ac. cervicornis, and Ac. palmata and their hybrid ("Ac. prolifera"). Aquarickettsia was found in all acroporids, with coral host and geographic location impacting the infection magnitude. Phylogenomic and genome-wide single-nucleotide variant analysis of Aquarickettsia found phylogenetic clustering by geographic region, not by coral taxon. Analysis of Aquarickettsia fixation indices suggests multiple sequential infections of the same coral colony are unlikely. Furthermore, relative to other Rickettsiales species, Aquarickettsia is undergoing positive selection, with Florida populations experiencing greater positive selection relative to other Caribbean locations. This may be due in part to Aquarickettsia proliferating in response to greater nutrient stress in Florida, as indicated by greater in situ replication rates in these corals. Aquarickettsia was not found to significantly codiversify with either the coral animal or the coral's algal symbiont (Symbiodinium "fitti"). Quantitative PCR analysis showed that gametes, larvae, recruits, and juveniles from susceptible, captive-reared coral genets were not infected with Aquarickettsia. Thus, horizontal transmission of Aquarickettsia via coral mucocytes or an unidentified host is more likely. The prevalence of Aquarickettsia in Ac. cervicornis and its high abundance in the Florida coral population suggests that coral disease mitigation efforts focus on preventing early infection via horizontal transmission.


Assuntos
Antozoários , Dinoflagelados , Animais , Antozoários/microbiologia , Região do Caribe , Recifes de Corais , Filogenia , Rickettsiales
4.
Elife ; 102021 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-34951405

RESUMO

Many animals are dependent on microbial partners that provide essential nutrients lacking from their diet. Ticks, whose diet consists exclusively on vertebrate blood, rely on maternally inherited bacterial symbionts to supply B vitamins. While previously studied tick species consistently harbor a single lineage of those nutritional symbionts, we evidence here that the invasive tick Hyalomma marginatum harbors a unique dual-partner nutritional system between an ancestral symbiont, Francisella, and a more recently acquired symbiont, Midichloria. Using metagenomics, we show that Francisella exhibits extensive genome erosion that endangers the nutritional symbiotic interactions. Its genome includes folate and riboflavin biosynthesis pathways but deprived functional biotin biosynthesis on account of massive pseudogenization. Co-symbiosis compensates this deficiency since the Midichloria genome encompasses an intact biotin operon, which was primarily acquired via lateral gene transfer from unrelated intracellular bacteria commonly infecting arthropods. Thus, in H. marginatum, a mosaic of co-evolved symbionts incorporating gene combinations of distant phylogenetic origins emerged to prevent the collapse of an ancestral nutritional symbiosis. Such dual endosymbiosis was never reported in other blood feeders but was recently documented in agricultural pests feeding on plant sap, suggesting that it may be a key mechanism for advanced adaptation of arthropods to specialized diets.


Assuntos
Francisella/metabolismo , Ixodidae/microbiologia , Rickettsiales/metabolismo , Animais , Francisella/genética , Transferência Genética Horizontal , Ixodidae/fisiologia , Rickettsiales/genética , Simbiose/fisiologia , Complexo Vitamínico B/biossíntese
5.
Nat Commun ; 12(1): 3324, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083540

RESUMO

Elucidating the timescale of the evolution of Alphaproteobacteria, one of the most prevalent microbial lineages in marine and terrestrial ecosystems, is key to testing hypotheses on their co-evolution with eukaryotic hosts and Earth's systems, which, however, is largely limited by the scarcity of bacterial fossils. Here, we incorporate eukaryotic fossils to date the divergence times of Alphaproteobacteria, based on the mitochondrial endosymbiosis that mitochondria evolved from an alphaproteobacterial lineage. We estimate that Alphaproteobacteria arose ~1900 million years (Ma) ago, followed by rapid divergence of their major clades. We show that the origin of Rickettsiales, an order of obligate intracellular bacteria whose hosts are mostly animals, predates the emergence of animals for ~700 Ma but coincides with that of eukaryotes. This, together with reconstruction of ancestral hosts, strongly suggests that early Rickettsiales lineages had established previously underappreciated interactions with unicellular eukaryotes. Moreover, the mitochondria-based approach displays higher robustness to uncertainties in calibrations compared with the traditional strategy using cyanobacterial fossils. Further, our analyses imply the potential of dating the (bacterial) tree of life based on endosymbiosis events, and suggest that previous applications using divergence times of the modern hosts of symbiotic bacteria to date bacterial evolution might need to be revisited.


Assuntos
Alphaproteobacteria/classificação , Alphaproteobacteria/genética , Eucariotos/classificação , Eucariotos/genética , Evolução Molecular , Fósseis , Animais , Cianobactérias/classificação , Cianobactérias/genética , Fósseis/história , Fósseis/microbiologia , Genoma Bacteriano , Genoma Mitocondrial , História Antiga , Mitocôndrias/genética , Mitocôndrias/microbiologia , Modelos Biológicos , Modelos Genéticos , Filogenia , Rickettsiales/classificação , Rickettsiales/genética , Simbiose/genética , Fatores de Tempo
6.
Med Vet Entomol ; 35(4): 595-606, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34180074

RESUMO

To determine Borrelia spp. (Spirochaetales: Spirochaetaceae) prevalence and species distribution in Northern Germany, Ixodes ticks were sampled from April to October in 2018 and 2019 by the flagging method at three locations each in five regions. Analysis by quantitative real-time PCR of 3150 individual ticks revealed an overall prevalence of 30.6%, without significant differences between tick stages (31.7% positive adults, 28.6% positive nymphs). Significant differences were observed in seasonal infection rates, but not between regions, landscape types or sampling years. Analysis of co-infections with Rickettsiales indicated a negative association between Borrelia and Anaplasma phagocytophilum infection. The most frequent Borrelia species differentiated by Reverse Line Blot were B. afzelii and B. garinii/B. bavariensis, followed by B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii and B. lusitaniae. Furthermore, B. miyamotoi was identified in 12.9% of differentiable samples. No effect of region nor landscape type on species composition was found, but significant variations in the distribution at the different sampling sites within a region were observed. The detected monthly fluctuations in prevalence and the differences in intra-regional Borrelia species distribution underline the importance of long-term and multi-location monitoring of Borrelia spp. in ticks as an essential part of public health assessment.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Borrelia , Coinfecção , Ixodes , Animais , Coinfecção/epidemiologia , Coinfecção/veterinária , Alemanha/epidemiologia , Rickettsiales
7.
PLoS Negl Trop Dis ; 15(5): e0009353, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33983936

RESUMO

Rickettsial diseases are a group of vector-borne bacterial infections that cause acute febrile illness with potentially severe or fatal complications. These vector-borne diseases are prevalent in tropical and subtropical regions worldwide and disproportionately affect poorer communities but are scientifically underrecognized. Despite this, they are not included in the World Health Organization's list of neglected tropical diseases nor were they mentioned in Peter Hotez's recent reflections on "What constitutes a neglected tropical disease?" in PLOS Neglected Tropical Diseases [1]. Here we present the case that rickettsial infections, as an overlooked cause of morbidity, mortality, and economic losses in marginalized populations, should be recognized as neglected tropical diseases. We describe how this oversight is the result of a number of factors and how it negatively impacts patient outcomes. We then propose measures to address the neglect of rickettsial infections in both scientific research and public health interventions.


Assuntos
Doenças Negligenciadas/microbiologia , Pobreza/estatística & dados numéricos , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/microbiologia , Saúde Global , Humanos , Doenças Negligenciadas/patologia , Saúde Pública , Rickettsiales/isolamento & purificação , Medicina Tropical
8.
Commun Biol ; 4(1): 628, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040152

RESUMO

Recent advances in culture-independent microbiological analyses have greatly expanded our understanding of the diversity of unculturable microbes. However, human pathogenic bacteria differing significantly from known taxa have rarely been discovered. Here, we present the complete genome sequence of an uncultured bacterium detected in human respiratory tract named IOLA, which was determined by developing a protocol to selectively amplify extremely AT-rich genomes. The IOLA genome is 303,838 bp in size with a 20.7% GC content, making it the smallest and most AT-rich genome among known human-associated bacterial genomes to our best knowledge and comparable to those of insect endosymbionts. While IOLA belongs to order Rickettsiales (mostly intracellular parasites), the gene content suggests an epicellular parasitic lifestyle. Surveillance of clinical samples provides evidence that IOLA can be predominantly detected in patients with respiratory bacterial infections and can persist for at least 15 months in the respiratory tract, suggesting that IOLA is a human respiratory tract-associated bacterium.


Assuntos
Genoma Bacteriano/genética , Sistema Respiratório/microbiologia , Rickettsiales/genética , Bactérias/genética , Composição de Bases/genética , Genoma Humano/genética , Humanos , Filogenia , Doenças Respiratórias/genética , Doenças Respiratórias/microbiologia , Rickettsiales/patogenicidade , Sequenciamento Completo do Genoma/métodos
9.
Ticks Tick Borne Dis ; 12(4): 101707, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33813285

RESUMO

Ticks harbour rich and diverse microbiota and, among the microorganisms associated with them, endosymbionts are the subject of a growing interest due to their crucial role in the biology of their arthropod host. Midichloria mitochondrii is the main endosymbiont of the European tick Ixodes ricinus and is found in abundance in all I. ricinus females, while at a much lower density in males, where it is even absent in 56 % of the individuals. This endosymbiont is also known to increase in numbers after the blood meal of larvae, nymphs or females. Because of this difference in the prevalence of M. mitochondrii between the two sexes, surveying the density of these bacteria in nymphs that will become either females or males could help to understand the behaviour of Midichloria in its arthropod host. To this aim, we have set up an experimental design by building 3 groups of unfed nymphs based on their scutum and hypostome lengths. After engorgement, weighing and moulting of a subset of the nymphs, a significant difference in sex-ratio among the 3 groups was observed. In parallel, Midichloria load in individual nymphs was quantified by qPCR both before and after engorgement. No difference in either body mass or Midichloria load was observed at the unfed stage, but following engorgement, both features were significantly different between each size group. Our results demonstrate that symbiont dynamics during nymphal engorgement is different between the two sexes, resulting in a significantly higher Midichloria load in nymphs that will become females. The consequences of those findings on our understanding of the interplay between the endosymbiont and its arthropod host are discussed.


Assuntos
Ixodes/microbiologia , Rickettsiales/fisiologia , Simbiose , Animais , Feminino , Ixodes/crescimento & desenvolvimento , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Fatores Sexuais
10.
Nat Rev Microbiol ; 19(6): 375-390, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33564174

RESUMO

The Rickettsiales are a group of obligate intracellular vector-borne Gram-negative bacteria that include many organisms of clinical and agricultural importance, including Anaplasma spp., Ehrlichia chaffeensis, Wolbachia, Rickettsia spp. and Orientia tsutsugamushi. This Review provides an overview of the current state of knowledge of the biology of these bacteria and their interactions with host cells, with a focus on pathogenic species or those that are otherwise important for human health. This includes a description of rickettsial genomics, bacterial cell biology, the intracellular lifestyles of Rickettsiales and the mechanisms by which they induce and evade the innate immune response.


Assuntos
Rickettsiales/fisiologia , Fenômenos Fisiológicos Bacterianos , Genoma Bacteriano , Humanos , Filogenia , Rickettsiales/classificação , Rickettsiales/genética
11.
J Fish Dis ; 44(5): 627-631, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33476400

RESUMO

Red mark syndrome (RMS) is a non-lethal inflammatory skin disorder spreading in farmed adult rainbow trout (Oncorhynchus mykiss) and reported worldwide. The aetiology is still uncertain, but positive correlation was found between Midichloria-like organism and RMS-affected fish. Here, we describe the first cases of RMS in Bosnia and Herzegovina. The outbreaks under study occurred in two intensive farms during the late winter and spring of 2020. Affected fish showed signs of disease ascribable to RMS, confirmed by pathological and molecular examination.


Assuntos
Surtos de Doenças/veterinária , Doenças dos Peixes/epidemiologia , Inflamação/veterinária , Oncorhynchus mykiss , Dermatopatias/veterinária , Animais , Bósnia e Herzegóvina/epidemiologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Inflamação/epidemiologia , Inflamação/microbiologia , Rickettsiales/fisiologia , Dermatopatias/epidemiologia , Dermatopatias/microbiologia
12.
Environ Microbiol ; 23(3): 1684-1701, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33470507

RESUMO

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.


Assuntos
Paramecium , Filogenia , RNA Ribossômico 16S/genética , Rickettsiales/genética , Simbiose/genética
13.
Parasitol Int ; 80: 102202, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33038482

RESUMO

Rural communities in Malaysia have been shown to be exposed to Coxiella, Borrelia and rickettsial infections in previous seroprevalence studies. Further research is necessary to identify the actual causative agents and the potential vectors of these infections. The arthropods parasitizing peri-domestic animals in these communities may serve as the vector in transmitting arthropod-borne and zoonotic agents to the humans. Molecular screening of bacterial and zoonotic pathogens from ticks and fleas collected from dogs, cats and chickens from six rural communities in Malaysia was undertaken. These communities were made up of mainly the indigenous people of Malaysia, known as the Orang Asli, as well as settlers in oil palm plantations. The presence of Coxiella burnetii, Borrelia, and rickettsial agents, including Rickettsia and Anaplasma, was investigated by performing polymerase chain reaction (PCR) and DNA sequencing. Candidatus Rickettsia senegalensis was detected in one out of eight pools of Ctenocephalides felis fleas. A relapsing fever group Borrelia sp. was identified from one of seven Haemaphysalis hystricis ticks tested. The results from the PCR screening for Anaplasma unexpectedly revealed the presence of Candidatus Midichloria sp., a potential tick endosymbiont, in two out of fourteen Haemaphysalis wellingtoni ticks tested. C. burnetii was not detected in any of the samples tested. The findings here provide evidence for the presence of potentially novel strains of rickettsial and borrelial agents in which their impact on public health risks among the rural communities in Malaysia merit further investigation. The detection of a potential endosymbiont of ticks also suggest that the presence of tick endosymbionts in the region is not fully explored.


Assuntos
Ctenocephalides/microbiologia , Ctenocephalides/parasitologia , Ixodidae/microbiologia , Ixodidae/parasitologia , Rickettsiales/isolamento & purificação , Anaplasma/isolamento & purificação , Animais , Borrelia/isolamento & purificação , Gatos/microbiologia , Gatos/parasitologia , Galinhas/microbiologia , Galinhas/parasitologia , Coxiella burnetii/isolamento & purificação , Cães/microbiologia , Cães/parasitologia , Malásia , Reação em Cadeia da Polimerase/veterinária , Rickettsiales/genética , População Rural , Análise de Sequência de DNA/veterinária
14.
Ticks Tick Borne Dis ; 11(5): 101489, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723635

RESUMO

In mountain areas of northwestern Italy, ticks were rarely collected in the past. In recent years, a marked increase in tick abundance has been observed in several Alpine valleys, together with more frequent reports of Lyme borreliosis. We then carried out a four-year study to assess the distribution and abundance of ticks and transmitted pathogens and determine their altitudinal limit in a natural park area in Piedmont region. Ixodes ricinus and Dermacentor marginatus were collected from both the vegetation and hunted wild ungulates. Tick abundance was significantly associated with altitude, habitat type and signs of animal presence, roe deer's in particular. Ixodes ricinus prevailed in distribution and abundance and, although their numbers decreased with increasing altitude, we recorded the presence of all active life stages of up to around 1700 m a.s.l., with conifers as the second most infested habitat after deciduous woods. Molecular analyses demonstrated the infection of questing I. ricinus nymphs with B. burgdorferi sensu lato (15.5 %), Rickettsia helvetica and R. monacensis (20.7 %), Anaplasma phagocytophilum (1.9 %), Borrelia miyamotoi (0.5 %) and Neoehrlichia mikurensis (0.5 %). One third of the questing D. marginatus were infected with R. slovaca. We observed a spatial aggregation of study sites infested by B. burgdorferi s.l. infected ticks below 1400 m. Borrelia-infected nymphs prevailed in open areas, while SFG rickettsiae prevalence was higher in coniferous and deciduous woods. Interestingly, prevalence of SFG rickettsiae in ticks doubled above 1400 m, and R. helvetica was the only pathogen detected above 1800 m a.s.l. Tick infestation on hunted wild ungulates indicated the persistence of tick activity during winter months and, when compared to past studies, confirmed the recent spread of I. ricinus in the area. Our study provides new insights into the population dynamics of ticks in the Alps and confirms a further expansion of ticks to higher altitudes in Europe. We underline the importance of adopting a multidisciplinary approach in order to develop effective strategies for the surveillance of tick-borne diseases, and inform the public about the hazard posed by ticks, especially in recently invaded areas.


Assuntos
Distribuição Animal , Dermacentor/microbiologia , Ixodes/microbiologia , Rickettsiales/isolamento & purificação , Infestações por Carrapato/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia , Altitude , Animais , Dermacentor/crescimento & desenvolvimento , Feminino , Itália/epidemiologia , Ixodes/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/microbiologia , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Prevalência , Infestações por Carrapato/parasitologia , Doenças Transmitidas por Carrapatos/microbiologia
15.
J Aquat Anim Health ; 32(2): 83-92, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32339356

RESUMO

Withering syndrome (WS) is a chronic bacterial disease that affects numerous northeastern Pacific abalone Haliotis spp. The causative agent of WS is an obligate intracellular Rickettsiales-like bacterium (WS-RLO) that remains unculturable, thereby limiting our understanding of WS disease dynamics. The objectives of our study were to (1) determine the temporal stability of WS-RLO DNA outside of its abalone host in 14°C and 18°C seawater, (2) develop a standardized protocol for exposing abalones to known concentrations of WS-RLO DNA, and (3) calculate the dose of WS-RLO DNA required to generate 50% infection prevalence (ID50) in the highly cultured red abalone Haliotis rufescens. The WS-RLO stability trials were conducted in October 2016, February 2017, and June 2017. A quantitative PCR (qPCR) analysis was used to quantify bacterial DNA for 7 d in seawater collected at an abalone farm in southern California, where the pathogen is now endemic. For all trials and temperature treatments, WS-RLO DNA was unstable in seawater for longer than 2 d. To determine an ID50, groups of uninfected juvenile red abalone were subjected to 3-h bath exposures with four concentrations of WS-RLO at 0, 103 , 104 , and 105 DNA copies/mL. Abalone feces were tested biweekly for the presence of WS-RLO DNA, and abalone tissues were sampled 9 weeks postinfection for histological and qPCR analyses. The ID50 results indicated that our protocol was successful in generating WS-RLO infections; a pathogen dose of 2.3 × 103 DNA copies/mL was required to generate a 50% infection prevalence in red abalone tissue. These findings are critical components of disease dynamics that will help assess WS transmission risk within and among abalone populations and facilitate appropriate management and restoration strategies for both wild and cultured abalone species in WS-endemic areas.


Assuntos
DNA Bacteriano/química , Gastrópodes/microbiologia , Interações Hospedeiro-Patógeno , Rickettsiales/genética , Animais , California , Água do Mar/química , Temperatura
16.
J Econ Entomol ; 113(3): 1486-1492, 2020 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-32207826

RESUMO

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important insect pest of the citrus crop worldwide. It vectors the pathogen 'Candidatus Liberibacter asiaticus' (CLas) that causes a serious disease known as citrus greening. Here, we tested the infection frequency of Wolbachia and CLas from 100 D. citri individuals collected from two host plants belonging to families Rutaceae (Citrus reticulata Blanco) and Boraginaceae (Cordia myxa L.) using molecular methods. The following trend of endosymbionts infection in adult D. citri was found; 85.4% (35/41) by Wolbachia, and 19.5% (8/41) by CLas collected from C. reticulata plants and 65.4% (17/26) by Wolbachia, and 15.4% (4/26) by CLas in case of C. myxa plant. However, 61.5% (8/13) nymphs collected from C. reticulata and 20.0% (4/20) collected from C. myxa plants were infected by Wolbachia, while no nymph was infected by CLas collected from either host plants. Findings from this work represent the first report of CLas presence in D. citri feeding on C. myxa plants. By studying the presence of CLas with other endosymbiotic bacteria, future basic and applied research to develop control strategies can be prioritized.


Assuntos
Anaplasmataceae , Boraginaceae , Citrus , Cordia , Hemípteros , Rhizobiaceae , Rutaceae , Wolbachia , Animais , Doenças das Plantas , Rickettsiales
17.
Ticks Tick Borne Dis ; 11(2): 101330, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31786146

RESUMO

A molecular survey was undertaken to determine the presence of protozoal and bacterial organisms in 120 ticks and 87 blood samples collected from mammals in north-eastern Algeria. Eight tick species were morphologically identified including 70 Rhipicephalus (Boophilus) annulatus, 23 Rhipicephalus bursa, five Rhipicephalus sanguineus sensu lato, 11 Hyalomma impeltatum, five Hyalomma scupense, two Hyalommma marginatum, one Hyalomma anatolicum and three Ixodes ricinus. Quantitative PCR screening of the ticks showed that Theileria annulata, "Candidatus Ehrlichia urmitei", Theileria buffeli and Anaplasma platys were detected in Rh. annulatus. Rickettsia massiliae and Anaplasma ovis were detected in Rh. sanguineus s.l. and Rh. bursa. Rickettsia aeschlimannii was detected in Hy. marginatum, Hy. scupense and Hy. impeltatum. Finally, "Candidatus Rickettsia barbariae" was detected in Rh. bursa. In the screening blood samples, Theileria equi, T.annulata, T. buffeli, Babesia bovis, Anaplasma marginale, A. ovis and Borrelia spp. were detected in cattle. Theileria ovis, T. annulata, and A. ovis were detected in sheep. In addition, A. ovis and T. equi were detected in goats and equidea respectively. In this study, T. equi and "Candidatus Rickettsia barbariae" were identified for the first time in Algeria as well as potential new species of Ehrlichia and Anaplasma. Although molecular detection does not indicate vector/reservoir competence when investigating ticks removed from animals, this study expands the knowledge of the microorganisms detected in ticks in north-east of Algeria.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças das Cabras/epidemiologia , Infecções por Bactérias Gram-Negativas/veterinária , Doenças dos Cavalos/epidemiologia , Doenças dos Ovinos/epidemiologia , Theileriose/epidemiologia , Infestações por Carrapato/veterinária , Argélia/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Doenças das Cabras/microbiologia , Doenças das Cabras/parasitologia , Cabras , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Doenças dos Cavalos/microbiologia , Doenças dos Cavalos/parasitologia , Cavalos , Ixodidae/fisiologia , Filogenia , Prevalência , Rickettsiales/classificação , Rickettsiales/genética , Rickettsiales/isolamento & purificação , Ovinos , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Theileria/classificação , Theileria/genética , Theileria/isolamento & purificação , Theileriose/parasitologia , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/microbiologia , Infestações por Carrapato/parasitologia
18.
Sci Rep ; 9(1): 18680, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822714

RESUMO

Rickettsiales bacteria in arthropods play a significant role in both public health and arthropod ecology. However, the extensive genetic diversity of Rickettsiales endosymbionts of arthropods is still to be discovered. In 2016, 515 arthropods belonging to 9 species of four classes (Insecta, Chilopoda, Diplopoda and Arachnida) were collected in Serbia. The presence and genetic diversity of Rickettsiales bacteria were evaluated by characterizing the 16S rRNA (rrs), citrate synthase (gltA) and heat shock protein (groEL) genes. The presence of various Rickettsiales bacteria was identified in the majority of tested arthropod species. The results revealed co-circulation of five recognized Rickettsiales species including Rickettsia, Ehrlichia and Wolbachia, as well as four tentative novel species, including one tentative novel genus named Neowolbachia. These results suggest the remarkable genetic diversity of Rickettsiales bacteria in certain arthropod species in this region. Furthermore, the high prevalence of spotted fever group Rickettsia in Ixodes ricinus ticks highlights the potential public health risk of human Rickettsia infection.


Assuntos
Biodiversidade , Variação Genética , Ixodes/microbiologia , Rickettsiales/classificação , Animais , Evolução Biológica , DNA Bacteriano/genética , Filogenia , RNA Ribossômico 16S/genética , Rickettsiales/isolamento & purificação , Estações do Ano , Sérvia
19.
Exp Appl Acarol ; 79(1): 137-155, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31489558

RESUMO

The objective of the present study was to detect the chosen nucleotide DNA or RNA sequences of the pathogens in ticks of domestic and wild animals of Kerala, South India based on molecular techniques. Among 602 ticks collected, 413 were from bovines (cattle and buffalo), 26 from goats, 101 from dogs and 62 from wild animals. Amblyomma integrum, Am. gervaisi, Dermacentor auratus, Haemaphysalis bispinosa, Ha. intermedia, Ha. shimoga, Ha. spinigera, Rhipicephalus annulatus, Rh. microplus, Rh. haemaphysaloides and Rh. sanguineus s.l. were identified from various domestic and wild animals of Kerala. The cDNA synthesized from the RNA isolated from fully or partially engorged adult female/nymphal ticks was used as template for the specific polymerase chain reactions (PCR). Out of 602 ticks examined, nucleotide sequences of pathogens were detected in 28 ticks (4.65%). The nucleotide sequences of tick-borne pathogens like Theileria orientalis, Babesia vogeli, Hepatozoon canis, Anaplasma marginale, An. bovis, Rickettsia sp. closely related to Ri. raoultii, Ri. massiliae, Ri. africae and Ri. slovaca were detected. The identification of the previously unreported nucleotide sequences of rickettsial pathogens from India is of particular interest due to their zoonotic significance. The phylogenetic analysis of the major piroplasm surface protein (MPSP) gene of T. orientalis amplified from Rh. annulatus ticks revealed that they were genetically close to type 7, which belong to the highly pathogenic Ikeda group.


Assuntos
Animais Selvagens , Eucoccidiida/isolamento & purificação , Interações Hospedeiro-Parasita , Ixodidae , Piroplasmida/isolamento & purificação , Rickettsiales/isolamento & purificação , Infestações por Carrapato/veterinária , Animais , Índia , Ixodidae/microbiologia , Ixodidae/parasitologia , Ixodidae/fisiologia , Filogenia , Infestações por Carrapato/parasitologia
20.
Sci Rep ; 9(1): 13176, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511528

RESUMO

Diseases caused by Rickettsiales bacteria are a global public health problem. To better understand the diversity and origins of Rickettsiales infection in humans and animals, we sampled 134 febrile patients, 173 rodents and 43 shrews, as well as 358 ticks, from two cities in Jiangsu and Jiangxi provinces, China. Our data revealed a relatively high prevalence of scrub typhus cases in both localities. In addition, both serological tests and genetic analysis identified three patients infected with Anaplasma bovis, Rickettsia monacensis, and Orientia tsutsugamushi bacteria. Molecular epidemiological investigation revealed the co-circulation of multiple species of Rickettsiales bacteria in small mammals and ticks in both provinces, potentially including novel bacterial species. In sum, these data demonstrate the ongoing importance of Rickettsiales infection in China and highlight the need for the regular surveillance of local arthropods, mammals and humans.


Assuntos
Anaplasma/genética , Variação Genética , Orientia tsutsugamushi/genética , Rickettsia/genética , Tifo por Ácaros/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Anaplasma/fisiologia , Animais , China/epidemiologia , Feminino , Geografia , Humanos , Masculino , Orientia tsutsugamushi/fisiologia , Filogenia , Prevalência , Rickettsia/fisiologia , Rickettsiales/classificação , Rickettsiales/genética , Roedores/microbiologia , Tifo por Ácaros/microbiologia , Musaranhos/microbiologia , Carrapatos/microbiologia
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