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36 result(s) for "Rickettsiaceae - isolation "
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Diversity and metabolic potential of the microbiota associated with a soil arthropod
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.
Rickettsiaceae and Anaplasmataceae infections in Ixodes ricinus ticks from urban and natural forested areas of Poland
Background Ixodes ricinus is a major vector for a range of microbial pathogens and the most prevalent and widely distributed tick species on the European continent, occurring in both natural and urban habitats. Nevertheless, little is known about the relative density of ticks in these two ecologically distinct habitats and the diversity of tick-borne pathogens that they carry. Methods We compared densities of questing I. ricinus nymphs and adults in urban and natural habitats in Central and Northeastern Poland, assessed the prevalence and rate of co-infection with A. phagocytophilum, Rickettsia, Ehrlichia and ‘ Ca. Neoehrlichia spp.’ in ticks, and compared the diversity of tick-borne pathogens using molecular assays (PCR). Results Of the 1325 adults and nymphs, 6.2% were infected with at least one pathogen, with 4.4%, 1.7% and less than 0.5% being positive for the DNA of Rickettsia spp., A. phagocytophilum , Ehrlichia spp. and Ca . N. mikurensis, respectively. Although tick abundance was higher in natural habitats, the prevalence of the majority of pathogens was higher in urban forested areas. Conclusion We conclude that: (i) zoonotic genetic variants of A. phagocytophilum are widely distributed in the Polish tick population, (ii) although the diversity of tick borne pathogens was higher in natural habitats, zoonotic species/strains were detected only in urban forests, (iii) and we provide the first description of Ca. N. mikurensis infections in ticks in Poland.
Distribution and molecular characteristics of rickettsiae found in ticks across Central Mongolia
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.
Pilot survey of mosquitoes (Diptera: Culicidae) from southeastern Georgia, USA for Wolbachia and Rickettsia felis (Rickettsiales: Rickettsiaceae)
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.
Widespread occurrence of the micro-organism Wolbachia in ants
For more than 20 years, sex allocation in hymenopteran societies has been a major topic in insect sociobiology. A recurring idea was that relatedness asymmetries arising from their haplodiploid sex determination system would lead to various parent-offspring conflicts over optimal reproduction. A possible weakness of existing theory is that only interests of nuclear genes are properly accounted for. Yet, a diversity of maternally transmitted elements manipulate the reproduction of their host in many solitary arthropod groups. The bacterium Wolbachia is a striking example of such a selfish cytoplasmic element, with effects ranging from reproductive incompatibility between host strains, induction of parthenogenesis and feminization of males. This paper reports on a first PCR-based Wolbachia screening in ants. Out of 50 Indo-Australian species, 50% screened positive for an A-group strain. One of these species also harboured a B-group strain in a double infection. Various factors that might explain the unusually high incidence of Wolbachia in ants are discussed. In general, Wolbachia may represent a widespread and previously unrecognized party active in the conflicts of interest within social insect colonies.
Occurrence and transmission of facultative endosymbionts in aphids
The occurrence of a secondary bacterial symbiont (PASS) of pea aphid, Acyrthosiphon pisum (Harris), was detected by polymerase chain reaction (PCR) with specific nucleotide primers based on PASS 16S rDNA nucleotide sequences from over 80% (50/57) of clones of pea aphid collected from widely separated locations in California. PASS was also detected by PCR in both red and green phenotypes of rose aphid, Macrosiphum rosae (L.), but not in six other species of aphids examined, including blue alfalfa aphid (A. kondoi Shinji). The nucleotide sequences of the PCR-amplified, partial 16S rDNAs (1060 bp) from pea aphid and rose aphid were identical and 99.9% similar to the published 16S rDNA of PASS. PASS and a recently described new rickettsia of pea aphid (PAR) were transmitted by needle injection of hemolymph from positive pea aphid clones into negative clones and into blue alfalfa aphids. Both PASS and PAR were maintained in the offspring of some of the injected mother aphids via high rate of maternal transmission
Cat Scratch Disease, Bacillary Angiomatosis, and Other Infections Due to Rochalimaea
In 1982 a 32-year-old married bricklayer was admitted to a hospital in Rochester, New York, because of fever and subcutaneous nodules. The nodules were firm, 2 to 6 cm in diameter, and nontender and had appeared in the three weeks before admission. The patient's CD4+ lymphocyte count was 40 cells per cubic millimeter. During the first several days of hospitalization additional nodules appeared and the original nodules increased in size. Histologic examination demonstrated angioproliferation, and bacillary forms were identified in the lesions by Warthin-Starry staining, although standard bacterial cultures were negative. The patient was treated with oral erythromycin, and the . . .
Isolation of Rochalimaea Species from Cutaneous and Osseous Lesions of Bacillary Angiomatosis
BACILLARY angiomatosis is a newly recognized infectious disease, primarily affecting immunocompromised patients, most commonly those infected with the human immunodeficiency virus (HIV). The most common cutaneous lesions are angiomatous, tender papules or subcutaneous nodules, which occasionally resemble Kaposi's sarcoma. 1 2 3 4 In 1990, the agent of bacillary angiomatosis was identified as being closely related to Rochalimaea quintana on the basis of partial sequencing of the 16S ribosomal RNA gene (16S ribosomal DNA [rDNA]) extracted from infected tissue. 5 Recently, comparison of the 16S ribosomal RNA sequences of a proposed etiologic agent of cat scratch disease, Afipia felis, 6 7 8 9 with those of Bartonella bacilliformis, 8 R. . . .
New Findings from an Old Pathogen: Intraerythrocytic Bacteria (Family Anaplasmatacea) in Red-Backed Salamanders Plethodon cinereus
During a recent study of red-backed salamanders ( Plethodon cinereus ), we discovered an intraerythrocytic organism typified by violet-staining, intracellular inclusions, consistent with descriptions of Cytamoeba or Aegyptianella (bacteria). Here we characterize its taxonomic status using molecular techniques and ask basic questions about its nature. Blood smears from 102 salamanders were examined from Pennsylvania, New York, and Virginia to determine prevalence, and whole blood from several infected animals was tested using a PCR which targets the 16S rRNA gene of bacteria. Phylogenetic analysis of partial 16S rRNA gene sequence (1201 bp) indicated this organism was in the order Rickettsiales and is likely a member of the family Anaplasmatacea. The organism differed from currently described taxa and was clearly differentiated from Aegyptianella pullorum of birds and “ Candidatus Hemobacterium ranarum” (formally A. ranarum ) of frogs. Of all salamanders, 17 (16.7%) were infected and these were significantly larger (snout–vent length) and had higher body condition scores than uninfected ones, and males were more likely to be infected than females. Erythrocytes affected by the pathogen were 5% larger than unaffected ones, but otherwise similar in morphology. Infected animals tended to have a greater number of circulating white blood cells, based on estimates from smears, indicating a nonspecific response to the pathogen by the innate immune system. Given its phylogenetic position, this pathogen is likely transmitted by an arthropod vector, and the male-biased prevalence strongly implicates trombiculid mites, which also live in leaf litter and affect male salamanders more so than females.
The Agent of Bacillary Angiomatosis
BACILLARY angiomatosis (also called epithelioid angiomatosis) and cat scratch disease are important clinical disorders that are presumed to be infectious on the basis of direct visualization of microorganisms in diseased tissues. Because these organisms cannot be grown reproducibly, the identity of the presumed pathogen or pathogens remains unknown. Bacillary angiomatosis is a distinct vascular proliferative disease initially described in the skin and lymph nodes of patients seropositive for the human immunodeficiency virus (HIV). 1 , 2 Lesions from this disorder have been found to contain clusters of bacilli with positive results on Warthin—Starry staining that resemble those found in cat scratch disease, 3 , 4 although . . .