scholarly journals Coinfection with “Rickettsia sibirica subsp. mongolotimonae” and Rickettsia conorii in a Human Patient: a Challenge for Molecular Diagnosis Tools

2015 ◽  
Vol 53 (9) ◽  
pp. 3057-3062 ◽  
Author(s):  
María Mercedes Nogueras ◽  
Beatriz Roson ◽  
Sergio Lario ◽  
Isabel Sanfeliu ◽  
Immaculada Pons ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Rickettsia Conorii ◽  
Human Patient ◽  
Content Type ◽  
Rickettsia Sibirica ◽  
Dual Infections

Rickettsioses are zoonoses transmitted by vectors. More than one agent can coexist in vectors. Although vectors may transmit more than one microorganism to humans, information on dual infections is scarce. We present a case of a patient with an atypical rickettsiosis diagnosis in whom two species ofRickettsiawere detected.

scholarly journals Complete Genome Sequence of Streptococcus agalactiae Serotype III, Multilocus Sequence Type 335 Strain HU-GS5823, Isolated from a Human Patient in Japan with Severe Invasive Infection

2018 ◽  
Vol 7 (20) ◽  
Author(s):  
Kentaro Nagaoka ◽  
Satoshi Konno ◽  
Kazunori Murase ◽  
Taisei Kikuchi ◽  
Ichiro Nakagawa
Keyword(s):  
Genome Sequence ◽  
Streptococcus Agalactiae ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Sequence Type ◽  
Invasive Infection ◽  
Human Patient ◽  
Content Type ◽  
Elderly Individuals ◽  
Causal Pathogen

Streptococcus agalactiae is an important causal pathogen of neonatal and obstetric sepsis, and it may be involved in invasive infection in immunocompromised and elderly individuals. Here, we report the complete genome sequence of Streptococcus agalactiae serotype III strain HU-GS5823, which was isolated from a patient in Japan with an invasive infection.

scholarly journals Nonselective Persistence of a Rickettsia conorii Extrachromosomal Plasmid during Mammalian Infection

2016 ◽  
Vol 84 (3) ◽  
pp. 790-797 ◽  
Author(s):  
Sean P. Riley ◽  
Abigail I. Fish ◽  
Daniel A. Garza ◽  
Kaikhushroo H. Banajee ◽  
Emma K. Harris ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Genetic Manipulation ◽  
Fluorescent Proteins ◽  
Spotted Fever ◽  
Rickettsia Conorii ◽  
Mediterranean Spotted Fever ◽  
Extrachromosomal Dna ◽  
Content Type

Scientific analysis of the genusRickettsiais undergoing a rapid period of change with the emergence of viable genetic tools. The development of these tools for the mutagenesis of pathogenic bacteria will permit forward genetic analysis ofRickettsiapathogenesis. Despite these advances, uncertainty still remains regarding the use of plasmids to study these bacteria inin vivomammalian models of infection, namely, the potential for virulence changes associated with the presence of extrachromosomal DNA and nonselective persistence of plasmids in mammalian models of infection. Here, we describe the transformation ofRickettsia conoriiMalish 7 with the plasmid pRam18dRGA[AmTrCh]. TransformedR. conoriistably maintains this plasmid in infected cell cultures, expresses the encoded fluorescent proteins, and exhibits growth kinetics in cell culture similar to those of nontransformedR. conorii. Using a well-established murine model of fatal Mediterranean spotted fever, we demonstrate thatR. conorii(pRam18dRGA[AmTrCh]) elicits the same fatal outcomes in animals as its untransformed counterpart and, importantly, maintains the plasmid throughout infection in the absence of selective antibiotic pressure. Interestingly, plasmid-transformedR. conoriiwas readily observed both in endothelial cells and within circulating leukocytes. Together, our data demonstrate that the presence of an extrachromosomal DNA element in a pathogenic rickettsial species does not affect eitherin vitroproliferation orin vivoinfectivity in models of disease and that plasmids such as pRam18dRGA[AmTrCh] are valuable tools for the further genetic manipulation of pathogenic rickettsiae.

scholarly journals Taxonomic Relationships among Spotted Fever Group Rickettsiae as Revealed by Antigenic Analysis with Monoclonal Antibodies

1998 ◽  
Vol 36 (4) ◽  
pp. 887-896 ◽  
Author(s):  
Wenbin Xu ◽  
Didier Raoult
Keyword(s):  
Monoclonal Antibodies ◽  
Phylogenetic Analyses ◽  
Spotted Fever ◽  
Rickettsia Conorii ◽  
Spotted Fever Group ◽  
Antigenic Analysis ◽  
Taxonomic Relationships ◽  
Rickettsia Africae ◽  
Rickettsia Slovaca ◽  
Rickettsia Sibirica

The spotted fever group (SFG) is made up of more than 20 different rickettsial species and strains. Study of the taxonomic relationships among the group has been attempted by phenotypic, genotypic, and phylogenetic analyses. In this study, we determined taxonomic relationships among the SFG rickettsiae by comparative analysis of immunogenic epitopes reactive against a panel of monoclonal antibodies. A total of 98 monoclonal antibodies, which were directed against epitopes on the major immunodominant proteins or on the lipopolysaccharide-like antigens of strains of Rickettsia africae, Rickettsia conorii, Rickettsia massiliae, Rickettsia akari, Rickettsia sibirica, and Rickettsia slovaca, were used in the study. The distribution and expression of the epitopes among 29 SFG rickettsiae and Rickettsia bellii were assessed by determination of reaction titers in a microimmunofluorescence assay. The results were scored as numerical taxonomic data, and cluster analysis was used to construct a dendrogram. The architecture of this dendrogram was consistent with previous taxonomic studies, and the implications of this and other findings are discussed.

scholarly journals Complete Genome Sequence of Brucella abortus 134, a Biovar 1 Strain Isolated from Human

2012 ◽  
Vol 194 (23) ◽  
pp. 6658-6658 ◽  
Author(s):  
Yufei Wang ◽  
Yuehua Ke ◽  
Guangjun Gao ◽  
Qing Zhen ◽  
Xitong Yuan ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Brucella Abortus ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Human Patient ◽  
Content Type ◽  
The Common

ABSTRACTBrucella abortusis one of the common pathogens causing brucellosis in China. Here, we report the genome sequence ofB. abortusstrain 134, a strain isolated from a human patient and belonging to biovar 1, the most highly represented biovar amongB. abortus strains in China.

scholarly journals Genome Sequence of Rickettsia conorii subsp. israelensis, the Agent of Israeli Spotted Fever

2012 ◽  
Vol 194 (18) ◽  
pp. 5130-5131 ◽  
Author(s):  
Erwin Sentausa ◽  
Khalid El Karkouri ◽  
Catherine Robert ◽  
Didier Raoult ◽  
Pierre-Edouard Fournier
Keyword(s):  
Genome Sequence ◽  
Spotted Fever ◽  
Draft Genome ◽  
Rhipicephalus Sanguineus ◽  
Rickettsia Conorii ◽  
Content Type

ABSTRACTRickettsia conoriisubsp.israelensisis the agent of Israeli spotted fever. The present study reports the draft genome ofRickettsia conoriisubsp.israelensisstrain ISTT CDC1, isolated from aRhipicephalus sanguineustick collected in Israel.

scholarly journals Host-Directed Antimicrobial Drugs with Broad-Spectrum Efficacy against Intracellular Bacterial Pathogens

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Daniel M. Czyż ◽  
Lakshmi-Prasad Potluri ◽  
Neeta Jain-Gupta ◽  
Sean P. Riley ◽  
Juan J. Martinez ◽  
...  
Keyword(s):  
G Protein ◽  
Bacterial Pathogens ◽  
Host Cells ◽  
Rickettsia Conorii ◽  
Intracellular Bacteria ◽  
Targeted Therapeutics ◽  
Content Type ◽  
Cell Functions ◽  
Approved Drugs ◽  
Fda Approved Drugs

ABSTRACTWe sought a new approach to treating infections by intracellular bacteria, namely, by altering host cell functions that support their growth. We screened a library of 640 Food and Drug Administration (FDA)-approved compounds for agents that render THP-1 cells resistant to infection by four intracellular pathogens. We identified numerous drugs that are not antibiotics but were highly effective in inhibiting intracellular bacterial growth with limited toxicity to host cells. These compounds are likely to target three kinds of host functions: (i) G protein-coupled receptors, (ii) intracellular calcium signals, and (iii) membrane cholesterol distribution. The compounds that targeted G protein receptor signaling and calcium fluxes broadly inhibitedCoxiella burnetii,Legionella pneumophila,Brucella abortus, andRickettsia conorii, while those directed against cholesterol traffic strongly attenuated the intracellular growth ofC. burnetiiandL. pneumophila. These pathways probably support intracellular pathogen growth so that drugs that perturb them may be therapeutic candidates. Combining host- and pathogen-directed treatments is a strategy to decrease the emergence of drug-resistant intracellular bacterial pathogens.IMPORTANCEAlthough antibiotic treatment is often successful, it is becoming clear that alternatives to conventional pathogen-directed therapy must be developed in the face of increasing antibiotic resistance. Moreover, the costs and timing associated with the development of novel antimicrobials make repurposed FDA-approved drugs attractive host-targeted therapeutics. This paper describes a novel approach of identifying such host-targeted therapeutics against intracellular bacterial pathogens. We identified several FDA-approved drugs that inhibit the growth of intracellular bacteria, thereby implicating host intracellular pathways presumably utilized by bacteria during infection.

scholarly journals Beta Interferon-Mediated Activation of Signal Transducer and Activator of Transcription Protein 1 Interferes with Rickettsia conorii Replication in Human Endothelial Cells

2011 ◽  
Vol 79 (9) ◽  
pp. 3733-3743 ◽  
Author(s):  
Punsiri M. Colonne ◽  
Marina E. Eremeeva ◽  
Sanjeev K. Sahni
Keyword(s):  
Endothelial Cells ◽  
Neutralizing Antibodies ◽  
Spotted Fever ◽  
Janus Kinase ◽  
Rickettsia Conorii ◽  
Mediterranean Spotted Fever ◽  
Signal Transducer ◽  
Microvascular Endothelium ◽  
Content Type ◽  
Beta Interferon

ABSTRACTInfection of the endothelial cell lining of blood vessels withRickettsia conorii, the causative agent of Mediterranean spotted fever, results in endothelial activation. We investigated the effects ofR. conoriiinfection on the status of the Janus kinase (JAK)-signal transducer and activator of transcription protein (STAT) signaling pathway in human microvascular endothelial cells (HMECs), the most relevant host cell type, in light of rickettsial tropism for microvascular endotheliumin vivo.R. conoriiinfection induced phosphorylation of STAT1 on tyrosine 701 and serine 727 at 24, 48, and 72 h postinfection in HMECs. Employing transcription profile analysis and neutralizing antibodies, we further determined that beta interferon (IFN-β) production and secretion are critical for STAT1 activation. Secreted IFN-β further amplified its own expression via a positive-feedback mechanism, while expression of transcription factors interferon regulatory factor 7 (IRF7) and IRF9, implicated in the IFN-β–STAT1 feedback loop, was also induced. Metabolic activity of rickettsiae was essential for the IFN-β-mediated response(s) because tetracycline treatment inhibitedR. conoriireplication, IFN-β expression, and STAT1 phosphorylation. Inclusion of IFN-β-neutralizing antibody during infection resulted in significantly enhancedR. conoriireplication, whereas addition of exogenous IFN-β had the opposite inhibitory effect. Finally, small interfering RNA-mediated knockdown further confirmed a protective role for STAT1 against intracellularR. conoriireplication. In concert, these findings implicate an important role for IFN-β-mediated STAT1 activation in innate immune responses of vascular endothelium toR. conoriiinfection.

scholarly journals Molecular Diagnosis of Pneumocystis jirovecii Pneumonia by Use of Oral Wash Samples in Immunocompromised Patients: Usefulness and Importance of the DNA Target

2019 ◽  
Vol 57 (12) ◽  
Author(s):  
Lidia Goterris ◽  
Miguel Angel Mancebo Fernández ◽  
Juan Aguilar-Company ◽  
Vicenç Falcó ◽  
Isabel Ruiz-Camps ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Molecular Diagnosis ◽  
Small Subunit ◽  
Molecular Techniques ◽  
Pneumocystis Jirovecii ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Rrna Gene ◽  
Immunocompromised Patients ◽  
Content Type ◽  
Hiv Negative

ABSTRACT Pneumocystis jirovecii pneumonia (PJP) is an important cause of pneumonia in the HIV-negative immunocompromised population, for whom the fungal load is low, the differential diagnosis is difficult, and a bronchoalveolar lavage (BAL) sample is often not readily available. Molecular techniques have improved the microbiological diagnosis in this scenario. The usefulness of two real-time PCR techniques targeting nuclear single-copy and mitochondrial multicopy genes, respectively, applied to oral wash specimens (OW) for PJP diagnosis was assessed, and its accuracy was compared to a BAL fluid-based diagnosis. Immunocompromised patients having PJP in the differential diagnosis of an acute respiratory episode, and from whom OW and BAL or lung biopsy specimens were obtained ≤48 h apart, were retrospectively included. PCRs targeting the dihydropteroate synthase gene (DHPS) and the mitochondrial small-subunit (mtSSU) rRNA gene were performed in paired OW-BAL specimens. Thirty-six patients were included (88.6% HIV negative). Fifteen patients (41.7%) were classified as PJP, and a further 8 were considered P. jirovecii colonized. Quantification of DHPS and mtSSU in BAL fluid showed an accuracy of 96.9% and 93.0%, respectively, for PJP diagnosis, whereas a qualitative approach performed better when applied to OW (accuracy, 91.7%) irrespective of the PCR target studied (kappa = 1). Qualitative molecular diagnosis applied to OW showed an excellent performance for PJP diagnosis regardless of the target studied, being easier to interpret than the quantitative approach needed for BAL fluid.

scholarly journals Multicentric Comparative Assessment of the Bio-Evolution Toxoplasma gondii Detection Kit with Eight Laboratory-Developed PCR Assays for Molecular Diagnosis of Congenital Toxoplasmosis

2014 ◽  
Vol 53 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Denis Filisetti ◽  
Yvon Sterkers ◽  
Marie-Pierre Brenier-Pinchart ◽  
Sophie Cassaing ◽  
Frédéric Dalle ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Amniotic Fluid ◽  
Molecular Diagnosis ◽  
Internal Control ◽  
Congenital Toxoplasmosis ◽  
Research Network ◽  
Multicentric Study ◽  
Content Type ◽  
Pcr Assays ◽  
Commercial Kits

The detection ofToxoplasma gondiiin amniotic fluid is an essential tool for the prenatal diagnosis of congenital toxoplasmosis and is currently essentially based on the use of PCR. Although some consensus is emerging, this molecular diagnosis suffers from a lack of standardization and an extreme diversity of laboratory-developed methods. Commercial kits for the detection ofT. gondiiby PCR were recently developed and offer certain advantages; however, they must be assessed in comparison with optimized reference PCR assays. The present multicentric study aimed to compare the performances of the Bio-EvolutionT. gondiidetection kit and laboratory-developed PCR assays set up in eight proficient centers in France. The study compared 157 amniotic fluid samples and found concordances of 99% and 100% using 76T. gondii-infected samples and 81 uninfected samples, respectively. Moreover, taking into account the classification of the European Research Network on Congenital Toxoplasmosis, the overall diagnostic sensitivity of all assays was identical and calculated to be 86% (54/63); specificity was 100% for all assays. Finally, the relative quantification results were in good agreement between the kit and the laboratory-developed assays. The good performances of this commercial kit are probably in part linked to the use of a number of good practices: detection in multiplicate, amplification of the repetitive DNA target rep529, and the use of an internal control for the detection of PCR inhibitors. The only drawbacks noted at the time of the study were the absence of uracil-N-glycosylase and small defects in the reliability of the production of different reagents.

scholarly journals Recombinant Antigen-Based Enzyme-Linked Immunosorbent Assay for Diagnosis of Baylisascaris procyonis Larva Migrans

2011 ◽  
Vol 18 (10) ◽  
pp. 1650-1655 ◽  
Author(s):  
Sriveny Dangoudoubiyam ◽  
Ramesh Vemulapalli ◽  
Momar Ndao ◽  
Kevin R. Kazacos
Keyword(s):  
Immunosorbent Assay ◽  
Cross Reactivity ◽  
Larva Migrans ◽  
Enzyme Linked Immunosorbent Assay ◽  
Parasitic Infections ◽  
Serum Samples ◽  
Western Blot Assay ◽  
Human Patient ◽  
Content Type ◽  
Baylisascaris Procyonis

ABSTRACTBaylisascarislarva migrans is an important zoonotic disease caused byBaylisascaris procyonis, the raccoon roundworm, and is being increasingly considered in the differential diagnosis of eosinophilic meningoencephalitis in children and young adults. Although aB. procyonisexcretory-secretory (BPES) antigen-based enzyme-linked immunosorbent assay (ELISA) and a Western blot assay are useful in the immunodiagnosis of this infection, cross-reactivity remains a major problem. Recently, a recombinantB. procyonisantigen, BpRAG1, was reported for use in the development of improved serological assays for the diagnosis ofBaylisascarislarva migrans. In this study, we tested a total of 384 human patient serum samples in a BpRAG1 ELISA, including samples from 20 patients with clinicalBaylisascarislarva migrans, 137 patients with other parasitic infections (8 helminth and 4 protozoan), and 227 individuals with unknown/suspected parasitic infections. A sensitivity of 85% and a specificity of 86.9% were observed with the BpRAG1 ELISA, compared to only 39.4% specificity with the BPES ELISA. In addition, the BpRAG1 ELISA had a low degree of cross-reactivity with antibodies toToxocarainfection (25%), while the BPES antigen showed 90.6% cross-reactivity. Based on these results, the BpRAG1 antigen has a high degree of sensitivity and specificity and should be very useful and reliable in the diagnosis and seroepidemiology ofBaylisascarislarva migrans by ELISA.

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