scholarly journals The tribe Ehrlichieae and ehrlichial diseases.

1991 ◽  
Vol 4 (3) ◽  
pp. 286-308 ◽  
Author(s):  
Y Rikihisa
Keyword(s):  
Systemic Disease ◽  
The United States ◽  
Cross Reactivity ◽  
Etiologic Agent ◽  
16S Rrna Sequence ◽  
Intracellular Parasites ◽  
Potomac Horse Fever ◽  
Ehrlichia Risticii ◽  
16S Rrna Sequence Analysis ◽  
Human Ehrlichiosis

The tribe Ehrlichieae consists of gram-negative minute cocci that are obligate intracellular parasites classified in the family Rickettsiaceae. Although ehrlichial organisms have been observed in leukocytes for many years, only a few species have been cultured in quantities sufficient for biochemical and molecular analyses. Recents studies on 16S-rRNA sequence analysis and energy metabolism showed that the genus Ehrlichia is closely related to the genus Rickettsia. There is, however, no antigenic cross-reactivity between these genera. Ehrlichial organisms cause a disease called "ehrlichiosis," a noncontagious infectious disease known to be transmitted by a tick in several cases and by a fluke in one case. Ehrlichia spp. infect dogs, ruminants, horses, and humans. Recently, two new ehrlichial diseases, Potomac horse fever and human ehrlichiosis, were discovered in the United States. The etiologic agent of Potomac horse fever, Ehrlichia risticii, is closely related to the known human pathogen Ehrlichia sennetsu. The etiologic agent of human ehrlichiosis is related to Ehrlichia canis, a canine pathogen. In contrast to the genus Rickettsia, members of the tribe Ehrlichieae reside primarily in the cytoplasmic vacuoles of monocytes or granulocytes and cause hematologic abnormalities, lymphadenopathy, and other pathologic changes in the host. However, the actual mechanisms whereby Ehrlichia spp. infect leukocytes, multiply in them, and produce various forms of systemic disease have not been defined. Depending on the ehrlichial species involved, serologic or direct microscopic observation of stained blood smears is currently used to diagnose ehrlichial disease.

scholarly journals Real-Time PCR Assays for Rapid Identification of Common Aphanomyces astaci Genotypes

2021 ◽  
Vol 9 ◽  
Author(s):  
Marco Di Domenico ◽  
Valentina Curini ◽  
Riccardo Caprioli ◽  
Carla Giansante ◽  
Agata Mrugała ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Central Italy ◽  
The United States ◽  
Wide Distribution ◽  
Cross Reactivity ◽  
Etiologic Agent ◽  
Clinical Samples ◽  
Introduction Pathways ◽  
Aphanomyces Astaci

The oomycete Aphanomyces astaci is the etiologic agent of crayfish plague, a disease that has seriously impacted the populations of European native crayfish species. The introduction of non-indigenous crayfish of North American origin and their wide distribution across Europe have largely contributed to spread of crayfish plague in areas populated by indigenous crayfish. Tracking A. astaci genotypes may thus be a useful tool for investigating the natural history of crayfish plague in its European range, as well as the sources and introduction pathways of the pathogen. In this study, we describe the development of real-time PCR TaqMan assays aiming to distinguish the five genotype groups of A. astaci (A–E) previously defined by their distinct RAPD patterns. The method was evaluated using DNA extracts from pure A. astaci cultures representing the known genotype groups, and from A. astaci-positive crayfish clinical samples collected mostly during crayfish plague outbreaks that recently occurred in Central Italy and Czechia. The assays do not cross-react with each other, and those targeting genotype groups A, B, D, and E seem sufficiently specific to genotype the pathogen from infected crayfish in the areas invaded by A. astaci (particularly Europe). The unusual A. astaci genotype “SSR-Up” documented from crayfish plague outbreaks in Czechia and chronically infected Pontastacus leptodactylus in the Danube is detected by the group B real-time PCR. The assay originally developed to detect group C (one not yet documented from crayfish plague outbreaks) showed cross-reactivity with Aphanomyces fennicus; the A. astaci genotype “rust1” described in the United States from Faxonius rusticus is detected by that assay as well. Analyses of additional markers (such as sequencing of the nuclear internal transcribed spacer or mitochondrial ribosomal subunits) may complement such cases when the real-time PCR-based genotyping is not conclusive. Despite some limitations, the method is a robust tool for fast genotyping of A. astaci genotype groups common in Europe, both during crayfish plague outbreaks and in latent infections.

scholarly journals 1021. Utility of Cell-Free DNA Sequencing in Diagnosing Murine typhus in Children

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S602-S602
Author(s):  
Victoria M Medina-Carbonell ◽  
Enrique A Yespica-Otaola ◽  
Kim Beatty ◽  
Jaime Fergie
Keyword(s):  
Average Length ◽  
Panel Member ◽  
Unknown Origin ◽  
The United States ◽  
Cross Reactivity ◽  
Etiologic Agent ◽  
Severe Illness ◽  
Murine Typhus ◽  
Cell Free Dna ◽  
Free Dna

Abstract Background Murine typhus is a zoonotic infection caused by Rickettsia typhi and transmitted through infected fleas. Geographic distribution within the United States is limited primarily to South Texas and Southern California. Infection is typically associated with a triad of fever, headache, and rash, although is only present in one-third of cases. Immunofluorescence assay (IFA) is currently the gold standard for diagnosis, but it has its limitations as it is dependent on the time to seroconversion and has low specificity due to cross-reactivity among other rickettsial species. Cell-free DNA (cfDNA) sequencing for broad-range pathogen detection may offer higher sensitivity at the early stages of the disease. Methods We performed a retrospective electronic medical record search of children with cfDNA sequencing detection of Murine typhus hospitalized at Driscoll Children’s Hospital, Corpus Christi, Texas, between June 2020 and May 2021. Results We found 4 children (range 9-15 year-old) positive for R. typhi by cfDNA sequencing. All patients presented with fever of unknown origin and rash. Also, 2 patients were diagnosed with pneumonia. One patient exhibited severe illness with acute kidney injury, elevation of transaminases and encephalitis that warranted admission to the pediatric intensive care unit. All patients defervesced and improved within 48 hours of doxycycline initiation; average length of stay 6 days (range 3-12 days). In one patient, M. typhus was detected by Karius® test only, in the other three was concordant with serology. Conclusion We highlight next-generation cfDNA sequencing as a useful tool in identifying the etiologic agent of patients with fever of known origin, where murine typhus is one of the possible etiologies. Preventing extensive laboratory workup and subsequent delay of assessment and management. The rapid turnaround time of cfDNA test allows for de-escalation of therapy and initiation of appropriate treatment. Disclosures Jaime Fergie, MD, AstraZeneca (Scientific Research Study Investigator)Explify (Speaker’s Bureau)Karius (Speaker’s Bureau)Pfizer, Merck, AstraZeneca, and Sanofi (Speaker’s Bureau)Pfizer, Merck, Sanofi, and Moderna (Consultant, Advisor or Review Panel member)

scholarly journals Thrombotic Thrombocytopenia after COVID-19 Vaccination: In Search of the Underlying Mechanism

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 559
Author(s):  
Piotr Rzymski ◽  
Bartłomiej Perek ◽  
Robert Flisiak
Keyword(s):  
Direct Interaction ◽  
Underlying Mechanism ◽  
The United States ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Vaccine Hesitancy ◽  
Future Research ◽  
Platelet Factor ◽  
Precautionary Measures ◽  
Adenoviral Proteins

The rollout of COVID-19 vaccines brings hope for successful pandemic mitigation and getting the transmission of SARS-CoV-2 under control. The vaccines authorized in Europe displayed a good safety profile in the clinical trials. However, during their post-authorization use, unusual thrombotic events associated with thrombocytopenia have rarely been reported for vector vaccines. This led to the temporary suspension of the AZD1222 vaccine (Oxford/AstraZeneca) in various European countries and the Ad26.COV2 vaccine (Janssen/Johnson&Johnson) in the United States, with regulatory bodies launching investigations into potential causal associations. The thromboembolic reactions were also rarely reported after mRNA vaccines. The exact cause of these adverse effects remains to be elucidated. The present paper outlines the hypotheses on the mechanisms behind the very rare thrombotic thrombocytopenia reported after the COVID-19 vaccination, along with currently existing evidence and future research prospects. The following are discussed: (i) the role of antibodies against platelet factor 4 (PF4), (ii) the direct interaction between adenoviral vector and platelets, (iii) the cross-reactivity of antibodies against SARS-CoV-2 spike protein with PF4, (iv) cross-reactivity of anti-adenovirus antibodies and PF4, (v) interaction between spike protein and platelets, (vi) the platelet expression of spike protein and subsequent immune response, and (vii) the platelet expression of other adenoviral proteins and subsequent reactions. It is also plausible that thrombotic thrombocytopenia after the COVID-19 vaccine is multifactorial. The elucidation of the causes of these adverse events is pivotal in taking precautionary measures and managing vaccine hesitancy. It needs to be stressed, however, that the reported cases are currently sporadic and that the benefits of COVID-19 vaccines vastly outweigh their potential risks.

scholarly journals Pseudomonas eucalypticola sp. nov., a producer of antifungal agents isolated from Eucalyptus dunnii leaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yujing Liu ◽  
Zhang Song ◽  
Hualong Zeng ◽  
Meng Lu ◽  
Weiyao Zhu ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Antifungal Agents ◽  
Novel Species ◽  
Phytopathogenic Fungi ◽  
Strictly Aerobic ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Eucalyptus Dunnii ◽  
16S Rrna Sequence Analysis

AbstractPseudomonas are ubiquitously occurring microorganisms and are known for their ability to produce antimicrobials. An endophytic bacterial strain NP-1 T, isolated from Eucalyptus dunnii leaves, exhibits antifungal properties against five tested phytopathogenic fungi. The strain is a Gram-negative rod-shaped bacterium containing a single polar flagellum. It is strictly aerobic, grows at 4–37 °C, 2–5% NaCl, and pH 3–7. The 16S rRNA sequence analysis showed that NP-1 T belongs to the Pseudomonas genus. Phylogenetic analysis based on four concatenated partial genes (16S rDNA, gyrB, rpoB and rpoD) and the phylogenomic tree indicated that NP-1 T belongs to Pseudomonas fluorescens lineage but is distinct from any known Pseudomonas species. The G + C mol % of NP-1 T genome is 63.96, and the differences between NP-1 T and related species are larger than 1. The digital DNA-DNA hybridization and tetranucleotide signatures are 23.8 and 0.97, which clearly separates strain NP-1 T from its closest neighbours, Pseudomonas coleopterorum and Pseudomonas rhizosphaerae. Its phenotypic and chemotaxonomic features confirmed its differentiation from related taxa. The results from this polyphasic approach support the classification of NP-1 T as a novel species of Pseudomonas, and the name of Pseudomonas eucalypticola is thus proposed for this strain, whose type is NP-1 T (= CCTCC M2018494T = JCM 33572 T).

Infection rate of Ehrlichia risticii, the agent of Potomac horse fever, in freshwater stream snails (Juga yrekaensis) from northern California

2000 ◽  
Vol 92 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Nicola Pusterla ◽  
Eileen Johnson ◽  
Joon-seok Chae ◽  
Jeannine Berger Pusterla ◽  
Elfriede DeRock ◽  
...  
Keyword(s):  
Infection Rate ◽  
Northern California ◽  
Potomac Horse Fever ◽  
Freshwater Stream ◽  
Ehrlichia Risticii

Isolation and characterization of phosphate solubilizing bacteria from the rhizospheric soil of Ponthenpuzha forest, Pathanamthitta (District), Kerala

2021 ◽  
Vol 16 (8) ◽  
pp. 110-117
Author(s):  
Kannan Abhirami ◽  
K. Jayakumar
Keyword(s):  
Bacterial Isolate ◽  
Phosphate Solubilizing Bacteria ◽  
Cymbopogon Citratus ◽  
16S Rrna Sequence ◽  
Isolation And Characterization ◽  
16S Rrna Sequence Analysis ◽  
Phosphate Solubilizing ◽  
Level Identification

Phosphorous is considered as a major parameter for crop yield. Its availability to plant is independent of its abundance. For the plants to utilize phosphorous, it is to be converted to absorbable form. Here, the part rendered by phosphate solubilizing bacteria is significant for it plays a crucial role in the formation of plant usable phosphate from organic forms. In the present work, an effort had been made to isolate and identify phosphate solubilising bacterial isolate from the rhizhospheric soils of various plants in Ponthenpuzha forest. One of the isolate from Cymbopogon citrates responded positively to Pikovskaya’s medium by producing a halo zone during in vitro culture. Colony features and 16S rRNA sequence analysis identified the isolate as Burkholderia sps. We have reported the presence of genus Burkholderia in the rhizospheric zone of Cymbopogon citratus. Further studies are warranted for species level identification of the isolate.

scholarly journals Case Report: Patient with Hepatitis C, p-ANCA, and Cryoglobulin Antibodies Presenting with Necrotizing Crescentic p-ANCA Glomerulonephritis

2018 ◽  
Vol 8 (2) ◽  
pp. 161-170
Author(s):  
Ramy M. Hanna ◽  
Naomi So ◽  
Marian Kaldas ◽  
Jean Hou ◽  
Farid Arman ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Crescentic Glomerulonephritis ◽  
The United States ◽  
Cross Reactivity ◽  
Normal Serum ◽  
Hcv Infection ◽  
Low Grade ◽  
Glomerular Injury ◽  
Immune Assays

Hepatitis C (HCV) infection has a prevalence of 3 million infected individuals in the United States, according to recent Center for Disease Control reports, and can have various renal manifestations. Cryoglobulins, antibodies that precipitate at colder temperatures in vitro, are a relatively common cause of renal disease in HCV infection. The cryoglobulin proteins can form occlusive aggregates in small glomerular capillary lumina or deposit in other areas of the glomerulus, resulting in hypocomplementemia, proteinuria, hematuria, and renal injury. The typical biopsy pattern is that of membranoproliferative glomerulonephritis (MPGN). There are, however, other HCV-related patterns of glomerular injury. Anti-neutrophil cytoplasmic antibodies (ANCA) are known to exist in HCV-infected patients. In many reported cases, ANCA serologic testing may appear positive due to cross-reactivity of the immune assays; however, the biopsy findings do not support ANCA-associated crescentic glomerulonephritis (GN)/vasculitis as the primary cause of glomerular injury. There are rare reports of microscopic polyangiitis (MPA) p-ANCA vasculitis, in patients with HCV infection. In comparison with the MPGN pattern of cryoglobulinemic glomerular injury, biopsies from these HCV-infected patients with concomitant MPA revealed a crescentic GN, associated with normal serum complement levels. We present a case of HCV-associated glomerular disease with the surprising biopsy finding of necrotizing and crescentic p-ANCA GN, with a background, low-grade mesangial immune complex GN. Thus, p-ANCA disease should also be considered in HCV-infected patients, in addition to the more typical lesions of MPGN or cryoglobulinemic GN.

scholarly journals Acquisition of an Agrobacterium Ri Plasmid and Pathogenicity by Other α-Proteobacteria in Cucumber and Tomato Crops Affected by Root Mat

2004 ◽  
Vol 70 (5) ◽  
pp. 2779-2785 ◽  
Author(s):  
S. A. Weller ◽  
D. E. Stead ◽  
J. P. W. Young
Keyword(s):  
Pathogenicity Test ◽  
Agrobacterium Radiobacter ◽  
Rrna Sequence ◽  
16S Rrna Sequence ◽  
Ri Plasmid ◽  
Fatty Acid Profiling ◽  
Transformation Rates ◽  
16S Rrna Sequence Analysis ◽  
Average Transformation

ABSTRACT Root mat of cucumbers and tomatoes has previously been shown to be caused by Agrobacterium radiobacter strains harboring a root-inducing Ri plasmid (pRi). Nine other pRi-harboring α-Proteobacteria have subsequently been isolated from root mat-infected crops. Fatty acid profiling and partial 16S rRNA sequence analysis identified three of these strains as being in the genus Ochrobactrum, five as being in the genus Rhizobium, and one as being in the genus Sinorhizobium. An in vitro pathogenicity test involving inoculation of cucumber cotyledons was developed. All pRi-harboring α-Proteobacteria induced typical root mat symptoms from the cotyledons. Average transformation rates for rhizogenic Ochrobactrum (46%) and Rhizobium (44%) strains were lower than those observed for rhizogenic A. radiobacter strains (64%). However, individual strains from these three genera all had transformation rates comparable to those observed from cotyledons inoculated with a rhizogenic Sinorhizobium strain (75%).

Purification, Properties and Mass Spectrometry Analysis of Two Novel Thermotolerant Endoglucanases from Bacillus akibai I-2

2011 ◽  
Vol 393-395 ◽  
pp. 911-915
Author(s):  
Sen Lin Liu ◽  
Miao Xing
Keyword(s):  
Mass Spectrometry ◽  
Soda Lakes ◽  
Maximum Activity ◽  
Mass Spectrometry Analysis ◽  
16S Rrna Sequence ◽  
Spectrometry Analysis ◽  
16S Rrna Sequence Analysis ◽  
Bacterium Strain ◽  
Terminal Amino ◽  
Alkaliphilic Bacterium

The alkaliphilic bacterium strain Ⅰ-2, which was isolated from soda lakes, was identified as Bacillus akibai by 16S rRNA sequence analysis and suggested to be a new subspecies of genus Bacillus. Two novel thermotolerant alkaline endoglucanases Ⅰ-2-A and Ⅰ-2-B were produced by this alkaliphilic strain. The purified Ⅰ-2-A and Ⅰ-2-B had molecular mass of approximately 60 and 90 kDa, respectively. The optimum pH of Ⅰ-2-A was about 9.0, while that of Ⅰ-2-B was about 8.0. Both enzymes exhibited maximum activity at around 50 °C and were stable up to 50 °C.The two enzymes were resistant to most metal ions and reagents examined. Mass spectrometry analysis indicated that Ⅰ-2-A was probably different from the endoglucanases reported. Ⅰ-2-B showed homology with those of family A5 endoglucanases but low similarity was found in C-terminal amino acid sequence.

scholarly journals SURG-26. READMISSION FOLLOWING RESECTION FOR PATIENTS WITH BRAIN METASTASES IN THE UNITED STATES

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi245-vi245
Author(s):  
Rupesh Kotecha ◽  
Muni Rubens ◽  
Sergio Gonzalez-Arias ◽  
Vitaly Siomin ◽  
Matthew Hall ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Brain Metastases ◽  
Systemic Disease ◽  
Significant Proportion ◽  
The United States ◽  
Patient Specific ◽  
Unplanned Readmission ◽  
Readmission Rates ◽  
Operative Care ◽  
Nationally Representative

Abstract OBJECTIVE Up to 30% of cancer patients will develop brain metastasis during the course of their systemic disease with a significant proportion undergoing resection of at least one lesion. The objective of the present study was to characterize the rates, predictors, and costs of 30-day readmissions following craniotomy for brain metastases using a nationally representative database. METHODS This study was a retrospective analysis of data from the Nationwide Readmissions Database (NRD) from 2010–2014. We included patients who underwent craniotomy for brain metastasis, identified using ICD-9-CM diagnosis (198.3) and procedure (01.59) codes. The primary outcome of the study was unplanned 30-day all-cause readmission rates. Secondary outcomes included predictors and costs of readmissions. RESULTS During the study period, there were 44,846 index hospitalizations for patients who underwent resection of brain metastasis. Among this cohort, 17.8% (n=7,965) had unplanned readmissions within the first 30 days after discharge from the index hospitalization. The readmission rate did not change significantly during the study period (P=0.286). The odds of unplanned readmission were significantly greater in patients with thromboembolic complications (aOR, 1.53; 95% CI: 1.18–2.01), patients with Elixhauser comorbidities >3 (aOR, 1.35; 95% CI: 1.22–1.50), male patients (adjusted odds ratio [aOR], 1.29; 95% CI: 1.17–1.42), patients with an initial length of stay ≥5 days (aOR, 1.02; 95% CI: 1.01–1.03). The median per-patient cost for 30-day unplanned readmission was $11,109 and this accounted for a total cost of $132.1 million during the study period. CONCLUSIONS Unplanned readmissions after resection for brain metastases involve substantial healthcare expenditures. Though there have been many interventions for improving surgical quality, post-operative care, and cost metrics, unplanned readmission rates have not changed. Key patient-specific variables and high rates of comorbidities should be considered to focus our efforts on patient selection for resection, and for strengthening existing interventions for high-risk patients.

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