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Sahni A, Alsing J, Narra HP, Montini M, Zafar Y, Sahni SK. Endothelial Mechanistic Target of Rapamycin Activation with Different Strains of R. rickettsii: Possible Role in Rickettsial Pathogenesis. Microorganisms 2024; 12:296. [PMID: 38399700 PMCID: PMC10892065 DOI: 10.3390/microorganisms12020296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/18/2024] [Accepted: 01/28/2024] [Indexed: 02/25/2024] Open
Abstract
Rickettsia rickettsii is an obligate intracellular pathogen that primarily targets endothelial cells (ECs), leading to vascular inflammation and dysfunction. Mechanistic target of rapamycin (mTOR) regulates several cellular processes that directly affect host immune responses to bacterial pathogens. Here, we infected ECs with two R. rickettsii strains, avirulent (Iowa) and highly virulent Sheila Smith (SS) to identify differences in the kinetics and/or intensity of mTOR activation to establish a correlation between mTOR response and bacterial virulence. Endothelial mTOR activation with the highly virulent SS strain was significantly higher than with the avirulent Iowa strain. Similarly, there was increased LC3-II lipidation with the virulent SS strain compared with the avirulent Iowa strain of R. rickettsii. mTOR inhibitors rapamycin and Torin2 significantly increased bacterial growth and replication in the ECs, as evidenced by a more than six-fold increase in rickettsia copy numbers at 48 h post-infection. Further, the knockdown of mTOR with Raptor and Rictor siRNA resulted in a higher rickettsial copy number and the altered expression of the pro-inflammatory cytokines interleukin (IL)-1α, IL-6, and IL-8. These results are the first to reveal that endothelial mTOR activation and the early induction of autophagy might be governed by bacterial virulence and have established the mTOR pathway as an important regulator of endothelial inflammation, host immunity, and microbial replication.
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Affiliation(s)
- Abha Sahni
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609, USA; (J.A.); (H.P.N.); (M.M.); (Y.Z.)
| | | | | | | | | | - Sanjeev K. Sahni
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609, USA; (J.A.); (H.P.N.); (M.M.); (Y.Z.)
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He M, Zhang L, Hu H, Liu X, Zhang C, Xin Y, Liu B, Chen Z, Xu K, Liu Y. Complete genome sequencing and comparative genomic analyses of a new spotted-fever Rickettsia heilongjiangensis strain B8. Emerg Microbes Infect 2023; 12:2153085. [PMID: 36440590 PMCID: PMC9930820 DOI: 10.1080/22221751.2022.2153085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rickettsia heilongjiangensis, a tick-borne obligate intracellular bacterium and causative agent of spotted fever in China, has attracted increasing concern regarding its capability in causing human rickettsiosis. Here, we conducted a genomic analysis of a new R. heilongjiangensis strain B8 (B8) isolated from the serum of a patient who had been bitten by a Haemaphysalis longicornis tick in Anhui Province, China. The present study sought to identify exclusive genes that might be associated with the pathogenicity of B8 using comparative genomics. Specifically, the sequences of B8 were assembled into one circular chromosome of 1,275,081 bp and predicted to contain 1447 genes. Comparative genome analyses were performed based on the genome of B8 and 28 spotted fever group (SFG) rickettsial genomes deposited in NCBI. Phylogenomic analyses indicated the B8 strain was clustered within the R. heilongjiangensis species; however, a sum of 112 and 119 B8-unique genes was identified when compared with R. heilongjiangensis and R. japonica strains, respectively. Functional annotation analyses revealed that these B8-unique genes were mainly annotated to defence mechanisms, lipid transport and metabolism, cell wall/membrane/envelope biogenesis. These data indicate B8 rather represents a previously undescribed human-pathogenic SFG rickettsia lineage, which may be an intermediate lineage of R. heilongjiangensis and R. japonica. Overall, this study isolated a new strain of R. heilongjiangensis in East-Central China for the first time, and provided potential B8-unique genetic loci that could be used for the discrimination of B8 from other R. heilongjiangensis and closely related SFG Rickettsial strains.
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Affiliation(s)
- Maozhang He
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Lifeng Zhang
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Haoran Hu
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Xiaohan Liu
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Cong Zhang
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Yu Xin
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Boyu Liu
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Zhen Chen
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China
| | - Kehan Xu
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China,Kehan Xu Department of Microbiology, School of Basic Medical, The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, No. 81 Meishan Road, Hefei, Anhui230032, People’s Republic of China
| | - Yan Liu
- Department of Microbiology, School of Basic Medical; The Key Laboratory of Microbiology and Parasitology of Anhui Province, The Key Laboratory of Zoonoses of High Institutions in Anhui, Anhui Medical University, Hefei, People’s Republic of China, Yan Liu
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Bei J, Qiu Y, Cockrell D, Chang Q, Husseinzadeh S, Zhou C, Fang X, Bao X, Jin Y, Gaitas A, Khanipov K, Saito TB, Gong B. Identification of common sequence motifs shared exclusively among selectively packed exosomal pathogenic microRNAs during rickettsial infections. J Cell Physiol 2023; 238:1937-1948. [PMID: 37334929 DOI: 10.1002/jcp.31061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/12/2023] [Accepted: 05/22/2023] [Indexed: 06/21/2023]
Abstract
We previously reported that microRNA (miR)23a and miR30b are selectively sorted into exosomes derived from rickettsia-infected endothelial cells (R-ECExos). Yet, the mechanism remains unknown. Cases of spotted fever rickettsioses have been increasing, and infections with these bacteria cause life-threatening diseases by targeting brain and lung tissues. Therefore, the goal of the present study is to further dissect the molecular mechanism underlying R-ECExos-induced barrier dysfunction of normal recipient microvascular endothelial cells (MECs), depending on their exosomal RNA cargos. Infected ticks transmit the rickettsiae to human hosts following a bite and injections of the bacteria into the skin. In the present study, we demonstrate that treatment with R-ECExos, which were derived from spotted fever group R parkeri infected human dermal MECs, induced disruptions of the paracellular adherens junctional protein VE-cadherin, and breached the paracellular barrier function in recipient pulmonary MECs (PMECs) in an exosomal RNA-dependent manner. We did not detect different levels of miRs in parent dermal MECs following rickettsial infections. However, we demonstrated that the microvasculopathy-relevant miR23a-27a-24 cluster and miR30b are selectively enriched in R-ECExos. Bioinformatic analysis revealed that common sequence motifs are shared exclusively among the exosomal, selectively-enriched miR23a cluster and miR30b at different levels. Taken together, these data warrant further functional identification and characterization of a monopartition, bipartition, or tripartition among ACA, UCA, and CAG motifs that guide recognition of microvasculopathy-relevant miR23a-27a-24 and miR30b, and subsequently results in their selective enrichments in R-ECExos.
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Affiliation(s)
- Jiani Bei
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yuan Qiu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Diane Cockrell
- Laboratory of Bacteriology, Division of Intramural Research, NIAID-NIH, Hamilton, Montana, USA
| | - Qing Chang
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Sorosh Husseinzadeh
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Changcheng Zhou
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Xiang Fang
- Department of Neurology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Xiaoyong Bao
- Department of Pediatric, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yang Jin
- Department of Medicine, Pulmonary and Critical Care Medicine Division, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Angelo Gaitas
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kamil Khanipov
- Department of Pharmacology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Tais B Saito
- Laboratory of Bacteriology, Division of Intramural Research, NIAID-NIH, Hamilton, Montana, USA
| | - Bin Gong
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
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Lamichhane S, Achhami E, Mahaju S, Gautam R, Adhikari A. A case of acute encephalitis syndrome and cranial nerve palsy secondary to scrub typhus: A rare presentation from Western Nepal. Clin Case Rep 2023; 11:e7376. [PMID: 37215963 PMCID: PMC10196419 DOI: 10.1002/ccr3.7376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/30/2023] [Accepted: 05/05/2023] [Indexed: 05/24/2023] Open
Abstract
Key Clinical Message This case report highlights the importance of considering scrub typhus as a differential diagnosis for acute encephalitis with cranial nerve palsy in the region of the tsutsugamushi triangle. Abstract Scrub typhus is a zoonotic rickettsiosis caused by the bacterium Orientia tsutsugamushi. This disease is endemic to a region called the tsutsugamushi triangle that extends from Southeast Asia to the Pacific Ocean. We report a 17-year-old girl from western Nepal who presented with fever, headache, vomiting, and altered sensorium, as well as bilateral lateral rectus palsy, dysphagia, regurgitation of food, dysarthria, and left-sided upper motor neuron type facial palsy. Following laboratory and imaging tests, the patient was diagnosed with scrub typhus and was treated successfully with high-dose dexamethasone and doxycycline. This case highlights the importance of considering scrub typhus in the differential diagnosis of encephalitis with cranial nerve palsy, especially in the region of the tsutsugamushi triangle. It also emphasizes the need for timely diagnosis and treatment of scrub typhus to prevent the development of various complications and ensure earlier recovery of patients.
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Affiliation(s)
| | - Eliz Achhami
- Sukraraj Tropical & Infectious Disease HospitalKathmanduNepal
| | - Satyam Mahaju
- Sukraraj Tropical & Infectious Disease HospitalKathmanduNepal
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Kask L, Påhlson C, Staxäng K, Nilsson K. Signatures in in vitro infection of NSC-34 mouse neurons and their cell nucleus with Rickettsia helvetica. BMC Microbiol 2023; 23:113. [PMID: 37085774 PMCID: PMC10120103 DOI: 10.1186/s12866-023-02859-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 04/11/2023] [Indexed: 04/23/2023] Open
Abstract
BACKGROUND Rickettsia helvetica, a spotted fever rickettsia, is transmitted to humans via ticks in Europe, North Africa, and Asia. The central nervous system is a crucial target for rickettsial diseases, which has been reported for 12 of the 31 species, of which R. helvetica is one. This study aimed, in an experimental model, to identify characteristics of R. helvetica infection in a mouse neuronal cell line, NSC-34. RESULTS NSC-34, a fusion cell line of mouse motor spinal cord neurons and neuroblastoma cells, was used as a model. Propagation of R. helvetica in neurons was confirmed. Short actin tails were shown at the polar end of the bacteria, which makes it likely that they can move intracellularly, and even spread between cells. Another protein, Sca4, which with the cell adhesion protein vinculin enables the passage of the cell membrane, was expressed during infection. No significant increase in TNFα levels was seen in the infected neurons, which is of interest because TNFα protects the host cell from infection-induced apoptotic death which is crucial for host cell survival. The bacteria were also shown to invade and grow in the cell nucleus of the neuron. CONCLUSIONS The findings suggest that a R. helvetica infection may be harmful to NSC-34 neurons under these in vitro conditions, but the full effects of the infection on the cell need to be studied further, also on human neurons, to also understand the possible significance of this infection in relation to pathogenetic mechanisms.
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Affiliation(s)
- Lena Kask
- Department of Medical Sciences, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden
| | - Carl Påhlson
- Department of Medical Sciences, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden
| | - Karin Staxäng
- Department of Immunology, Genetics and Pathology-Biovis Platform, Uppsala University, Uppsala, Sweden
| | - Kenneth Nilsson
- Department of Medical Sciences, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden.
- Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
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Martínez-Campos S, González-Pleiter M, Rico A, Schell T, Vighi M, Fernández-Piñas F, Rosal R, Leganés F. Time-course biofilm formation and presence of antibiotic resistance genes on everyday plastic items deployed in river waters. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130271. [PMID: 36351347 DOI: 10.1016/j.jhazmat.2022.130271] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/17/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The plastisphere has been widely studied in the oceans; however, there is little information on how living organisms interact with the plastisphere in freshwater ecosystems, and particularly on how this interaction changes over time. We have characterized, over one year, the evolution of the eukaryotic and bacterial communities colonizing four everyday plastic items deployed in two sites of the same river with different anthropogenic impact. α-diversity analyses showed that site had a significant role in bacterial and eukaryotic diversity, with the most impacted site having higher values of the Shannon diversity index. β-diversity analyses showed that site explained most of the sample variation followed by substrate type (i.e., plastic item) and time since first colonization. In this regard, core microbiomes/biomes in each plastic at 1, 3, 6 and 12 months could be identified at genus level, giving a global overview of the evolution of the plastisphere over time. The measured concentration of antibiotics in the river water positively correlated with the abundance of antibiotic resistance genes (ARGs) on the plastics. These results provide relevant information on the temporal dynamics of the plastisphere in freshwater ecosystems and emphasize the potential contribution of plastic items to the global spread of antibiotic resistance.
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Affiliation(s)
- Sergio Martínez-Campos
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, University of Alcalá, Alcalá de Henares, E-28871 Madrid, Spain
| | - Miguel González-Pleiter
- Department of Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain
| | - Andreu Rico
- IMDEA Water Institute, Science and Technology Campus of the Universidad de Alcalá, Av. Punto Com 2, 28805 Alcalá de Henares, Madrid, Spain; Cavanilles Institute of Biodiversity and Evolutionary Biology, Universidad de Valencia, c/ Catedrático José Beltrán 2, Paterna, 46980 Valencia, Spain
| | - Theresa Schell
- IMDEA Water Institute, Science and Technology Campus of the Universidad de Alcalá, Av. Punto Com 2, 28805 Alcalá de Henares, Madrid, Spain
| | - Marco Vighi
- IMDEA Water Institute, Science and Technology Campus of the Universidad de Alcalá, Av. Punto Com 2, 28805 Alcalá de Henares, Madrid, Spain
| | - Francisca Fernández-Piñas
- Department of Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain; Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, C Darwin 2, 28049 Madrid, Spain
| | - Roberto Rosal
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, University of Alcalá, Alcalá de Henares, E-28871 Madrid, Spain
| | - Francisco Leganés
- Department of Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain; Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, C Darwin 2, 28049 Madrid, Spain.
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Bei J, Qiu Y, Cockrell D, Chang Q, Husseinzadeh S, Zhou C, Gaitas A, Fang X, Jin Y, Khanipov K, Saito TB, Gong B. Identification of common sequence motifs shared exclusively among selectively packed exosomal pathogenic microRNAs during rickettsial infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.06.522907. [PMID: 36712112 PMCID: PMC9881928 DOI: 10.1101/2023.01.06.522907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
We previously reported that microRNA (miR)23a and miR30b are selectively sorted into rickettsia-infected, endothelial cell-derived exosomes ( R -ECExos). Yet, the mechanism remains unknown. The number of cases of spotted fever rickettsioses has been increasing in recent years, and infections with these bacteria cause life-threatening diseases by targeting brain and lung tissues. Therefore, the aim of the present study is to continue to dissect the molecular mechanism underlying R -ECExos-induced barrier dysfunction of normal recipient microvascular endothelial cells (MECs), depending on their exosomal RNA cargos. Rickettsiae are transmitted to human hosts by the bite of an infected tick into the skin. In the present study we demonstrate that treatment with R -ECExos, which were derived from spotted fever group R parkeri infected human dermal MECs, induced disruptions of the paracellular adherens junctional protein VE-cadherin and breached the paracellular barrier function in recipient pulmonary MECs (PMECs) in an exosomal RNA-dependent manner. Similarly, we did not detect different levels of miRs in parent dermal MECs following rickettsial infections. However, we demonstrated that the microvasculopathy-relevant miR23a-27a-24 cluster and miR30b are selectively enriched in R -ECExos. Bioinformatic analysis revealed that common sequence motifs are shared exclusively among the exosomal, selectively-enriched miR23a cluster and miR30b at different levels. Taken together, these data warrant further functional identification and characterization of a single, bipartition, or tripartition among ACA, UCA, and CAG motifs that guide recognition of microvasculopathy-relevant miR23a-27a-24 and miR30b, and subsequently results in their selective enrichments in R -ECExos.
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Molecular Detection of Rickettsia and Other Bacteria in Ticks and Birds in an Urban Fragment of Tropical Dry Forest in Magdalena, Colombia. LIFE (BASEL, SWITZERLAND) 2023; 13:life13010145. [PMID: 36676094 PMCID: PMC9861851 DOI: 10.3390/life13010145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/06/2023]
Abstract
Birds are important hosts in the life cycle of some species of ticks. In Colombia, there are few eco-epidemiological studies of tick-borne diseases; the existing ones have been focused on areas where unusual outbreaks have occurred. This study describes the identification of ticks collected from birds and vegetation, and the detection of bacteria in those ticks and in blood samples from birds in an urban fragment of tropical dry forest in the department of Magdalena, Colombia. Bird sampling was carried out monthly in 2021, and 367 birds, distributed among 41 species, were captured. All collected ticks were identified as Amblyomma sp. or Amblyomma dissimile. The presence of rickettsiae in ticks collected from birds was evaluated by molecular analysis of the gltA, ompA and sca1 genes. 16S rRNA meta-taxonomy was used to evaluate rickettsiae in ticks collected from vegetation and in blood samples from birds. The presence of the species "Candidatus Rickettsia colombianensi" was detected in ticks from birds. Bacteria of the family Rickettsiacea was the most abundant in ticks collected from vegetation. Bacteria of the families Staphylococcaceae, Comamonadaceae and Pseudomonadaceae were prevalent in the samples of blood from birds. Rickettsia spp. was also detected in low abundance in some of the bird blood samples.
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Condit ME, Jones E, Biggerstaff BJ, Kato CY. Procedure for spotted fever group Rickettsia isolation from limited clinical blood specimens. PLoS Negl Trop Dis 2022; 16:e0010781. [PMID: 36240222 PMCID: PMC9605293 DOI: 10.1371/journal.pntd.0010781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 10/26/2022] [Accepted: 08/30/2022] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Current isolation techniques for spotted fever group Rickettsia from clinical samples are laborious and are limited to tissue, blood and blood derivatives with volumes ideally greater than 1 mL. We validated the use of simplified methodologies for spotted fever group Rickettsia culture isolation that overcome sample volume limitations and provide utility in clinical diagnostics and research studies. METHODOLOGY/PRINCIPAL FINDINGS A modified cell culture method is evaluated for the isolation of Rickettsia ssp. from human diagnostic samples. Culture sampling method, culture platform, and growth phase analysis were evaluated to determine best practices for optimal culture isolation conditions. Rickettsial isolates (R. conorii, R. rickettsii, and R. parkeri) were grown in Vero E6 cells over a course of 5 to 7 days at low inoculum treatments (~40 bacterial copies) to standardize the sampling strategy at a copy number reflective of the bacteremia in acute diagnostic samples. This methodology was verified using small volumes (50 μL) of 25 unprocessed clinical whole blood, plasma, and serum samples from acute samples of patients suspected of having Rocky Mountain Spotted Fever, of which 10 were previously confirmed positive via the PanR8 qPCR assay, 13 had no detectable Rickettsia DNA by the PanR8 qPCR assay, and 2 were not previously tested; these samples resulted in the cultivation of 7 new R. rickettsii isolates. CONCLUSIONS/SIGNIFICANCE We observed that rickettsial isolate growth in culture is reproducibly identified by real-time PCR testing of culture media within 72 hours after inoculation. Additionally, specimen sedimentation prior to isolation to remove red blood cells was found to decrease the amount of total organism available in the inoculum. A small volume culture method was established focusing on comparative qPCR detection rather than bacterial visualization, taking significantly shorter time to detect, and requiring less manipulation compared to traditional clinical isolate culture methods.
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Affiliation(s)
- Marah E. Condit
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Emma Jones
- Office of the Director, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Brad J. Biggerstaff
- Office of the Director, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Cecilia Y. Kato
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America,* E-mail:
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Drexler NA, Close R, Yaglom HD, Traeger M, Parker K, Venkat H, Villarroel L, Brislan J, Pastula DM, Armstrong PA. Morbidity and Functional Outcomes Following Rocky Mountain Spotted Fever Hospitalization-Arizona, 2002-2017. Open Forum Infect Dis 2022; 9:ofac506. [PMID: 36324320 PMCID: PMC9605701 DOI: 10.1093/ofid/ofac506] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/30/2022] [Indexed: 10/07/2023] Open
Abstract
Background Rocky Mountain spotted fever (RMSF) is a deadly tickborne disease disproportionately affecting Arizona tribal communities. While the acute clinical effects of RMSF are well-documented, more complete understanding of the long-term health consequences is needed to provide guidance for providers and patients in highly impacted areas. Methods We performed a retrospective review of hospitalized RMSF cases from 2 tribal communities in Arizona during 2002-2017. Medical records from acute illness were abstracted for information on clinical presentation, treatment, and status at discharge. Surviving patients were interviewed about disease recovery, and patients reporting incomplete recovery were eligible for a neurologic examination. Results Eighty hospitalized cases of RMSF met our inclusion criteria and were reviewed. Of these, 17 (21%) resulted in a fatal outcome. Among surviving cases who were interviewed, most (62%) reported full recovery, 15 (38%) reported ongoing symptoms or reduced function following RMSF illness, and 9 (23%) had evidence of neurologic sequelae at the time of examination. Sequelae included impaired cognition, weakness, decreased deep tendon reflexes, seizures, and cranial nerve dysfunction. Longer hospitalization (25.5 days vs 6.2 days, P < .001), a higher degree of disability at discharge (median modified Rankin score 1 vs 0, P = .03), and delayed doxycycline administration (6.2 days vs 4.1 days, P = .12) were associated with long-term sequelae by logistic regression. Conclusions Although the etiology of sequelae is not able to be determined using this study design, life-altering sequelae were common among patients surviving severe RMSF illness. Delayed administration of the antibiotic doxycycline after day 5 was the strongest predictor of morbidity.
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Affiliation(s)
- Naomi A Drexler
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ryan Close
- Whiteriver Indian Hospital, Indian Health Service, Whiteriver, Arizona, USA
| | - Hayley D Yaglom
- Pathogen and Microbiome Division, Translational Genomics Research Institute, Flagstaff, Arizona, USA
- Office of Infectious Disease Services, Arizona Department of Health Services, Phoenix, Arizona, USA
| | - Marc Traeger
- Whiteriver Indian Hospital, Indian Health Service, Whiteriver, Arizona, USA
| | - Kristen Parker
- Whiteriver Indian Hospital, Indian Health Service, Whiteriver, Arizona, USA
| | - Heather Venkat
- Office of Infectious Disease Services, Arizona Department of Health Services, Phoenix, Arizona, USA
- Center for Preparedness and Response, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Lisa Villarroel
- Office of Infectious Disease Services, Arizona Department of Health Services, Phoenix, Arizona, USA
| | - Jeanette Brislan
- Gila River Healthcare Public Health Nursing, Sacaton, Arizona, USA
| | - Daniel M Pastula
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- University of Colorado School of Medicine and Colorado School of Public Health, Aurora, Colorado, USA
| | - Paige A Armstrong
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Gafarova MT, Bondarenko EI, Maliy KD, Alieva EE, Evstafiev IL, Tovpinec NN, Malaya NK, Kubyshkin AV. Prevalence of causative agents of transmissive tick-borned ricketsious in the Crimean peninsula. Klin Lab Diagn 2022; 67:170-176. [PMID: 35320633 DOI: 10.51620/0869-2084-2022-67-3-170-176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The paper presents the results of a study of the prevalence of Ixodid ticks - potential carriers of tick-borne rickettsiosis pathogens. Ectoparasites were collected in various natural and climatic zones of the Crimean Peninsula within the year 2016-2018. As a result of screening with the help of real-time PCR analysis (PCR-RT), a genetic marker (a section of the gltA gene) of the rickettsia group of tick-borne spotted fever was detected in ticks. The most common DNA marker of rickettsia was found in ticks in the eastern regions of the steppe zone - 50,6 %, in the north-western part of the steppe zone this value was 12,0 %. The least amount of rickettsia target DNA was detected in ticks collected in the mountain forest and south bank zones - 4,5 %. As a result of sequencing of positive DNA samples from fragments of the gltA, ompA, ompB, and sca4 genes, the species composition of rickettsias was established. The DNA of 8 species of rickettsia was identified: Circulation of three R. conorii, R. massiliae, R. sibirica subsp. mongolotimonae, R. slovaca, R. aeschlimannii, R. monacensis, R. helvetica, R. raoultii. R. massiliae, R. slovaca, and R. helvetica were established in the Crimean Peninsula for the first time. The peculiarities of the geographical distribution of the identified rickettsia species were determined, which was due to the spread of mites-carriers of pathogens. The revealed diversity of rickettsia species and their vectors, due to the isolation of the areas of the main feeding animals and the established routes of migratory birds, suggests the circulation of other rickettsia species on the territory of the Crimean Peninsula. The obtained results suggest that the diseases of tick-borne rickettsiosis in the Crimean Peninsula can be caused not only by R. conorii, as previously thought, but also by other types of rickettsii.
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Affiliation(s)
- M T Gafarova
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU
| | | | - K D Maliy
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU
| | - E E Alieva
- Federal State Budgetary Institution "N.I. Pirogov Saki Military Clinical Sanatorium", Ministry of Defense of Russia
| | - I L Evstafiev
- FBUZ "Center for Hygiene and Epidemiology in the Republic of Crimea and the federal city of Sevastopol"
| | - N N Tovpinec
- FBUZ "Center for Hygiene and Epidemiology in the Republic of Crimea and the federal city of Sevastopol"
| | - N K Malaya
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU
| | - A V Kubyshkin
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU
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12
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Pacheco-Silva AB, Martins EB, López AJR, Detepo PJT, Mamani RF, Japiassú AM, Lupi O, Mendes TV, Pina-Costa AD, Calvet GA, Bressan CDS, Silva MFBD, Ogino LL, Assis MRDS, Marques AM, Dias CMG, Borchert JM, Lemos ERSD, Brasil P. Fatal Brazilian spotted fever in a healthy military man during field training in Rio de Janeiro city, southeastern Brazil. Rev Inst Med Trop Sao Paulo 2022; 64:e77. [DOI: 10.1590/s1678-9946202264077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022] Open
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13
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Wallménius K, Påhlson C, Nilsson K. Retrospective serological study of Rickettsia spp. and Borrelia spp. antibodies in patients with peripheral facial nerve palsy. Infect Ecol Epidemiol 2021; 11:1987058. [PMID: 34712390 PMCID: PMC8547868 DOI: 10.1080/20008686.2021.1987058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
In a retrospective study, 36 patients with peripheral facial palsy were serologically evaluated for the presence of Rickettsia spp. and Borrelia spp. antibodies. All sera underwent immunofluorescence and Western blot analysis for IgG and IgM antibodies using Rickettsia helvetica and R. felis as antigens. Anti-Borrelia antibodies were detected using a commercial ELISA detecting Borrelia burgdorferi, B. afzelii and B. garinii. Three patients (8.3%) were seropositive for Rickettsia spp. with IgG titres equal to 1:128, and six patients (16.7%) had IgM titres equal to or above 1:128. All samples with IgG/IgM titres equal to or above 1:128 were confirmed by Western Blot. Four patients (11.1%) had IgG antibodies against Borrelia at a titre level normally judged to be indicative of current infection. Two of these patients had significant IgG or IgM titres for both Rickettsia spp. and Borrelia spp., indicating co-infection. In conclusion, the findings indicate current rickettsial infection or early response at about the same degree as for Lyme borreliosis in patients with facial palsy, but they need to be further examined with a larger number of patients and paired serum analyses.
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Affiliation(s)
- Katarina Wallménius
- Department of Medical Science, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden
| | - Carl Påhlson
- Department of Medical Science, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden
| | - Kenneth Nilsson
- Department of Medical Science, Section of Clinical Microbiology, Uppsala University, Uppsala, Sweden
- Department of Medical Science, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden
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14
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Lourenco J, Coelho J, Ribeiro P. Rickettsial fever leading to upper disphagya: A rare neurovascular conflict between vertebral artery and glossopharyngeal nerve. IDCases 2021; 26:e01250. [PMID: 34430208 PMCID: PMC8371192 DOI: 10.1016/j.idcr.2021.e01250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/08/2021] [Indexed: 11/29/2022] Open
Abstract
Rickettsial fevers are a common type of zoonosis with potential neurological involvement, mostly in form of meningoencephalitis. However, there are some rare cases that could compromise cranial nerves function through vascular inflammation. In this paper, we describe a rare case of dysphagia related to glossopharyngeal involvement by juxtaposed vertebral artery vasculitis.
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Affiliation(s)
- Jorge Lourenco
- Internal Medicine Department, Centro Hospitalar e Universitario de Coimbra, Portugal
| | - Joana Coelho
- Internal Medicine Department, Centro Hospitalar e Universitario de Coimbra, Portugal
| | - Pedro Ribeiro
- Internal Medicine Department, Centro Hospitalar e Universitario de Coimbra, Portugal
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15
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Díaz-Sánchez AA, Chilton NB, Roblejo-Arias L, Fonseca-Rodríguez O, Marrero-Perera R, Diyes CP, Yunik MEM, Lobo-Rivero E, Corona-González B. Molecular detection and identification of spotted fever group rickettsiae in ticks collected from horses in Cuba. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:207-212. [PMID: 32936461 DOI: 10.1111/mve.12480] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
Spotted fever group (SFG) rickettsiae are obligatory intracellular bacteria that cause disease in humans and other animals. Ixodid ticks are the principal vectors of SFG rickettsiae. The present study aimed to determine the prevalence and species identity of SFG rickettsiae in ticks and horses from urban and rural areas of western Cuba using PCR assays. Tick samples, collected from 79 horses, consisted of 14 Amblyomma mixtum adults, 111 Dermacentor nitens adults and 19 pools of D. nitens nymphs (2-5 individuals/pool). The PCR results revealed the presence of Rickettsia spp. in 64% of the A. mixtum adults, 16% of the D. nitens adults, and 11% of the pooled samples of D. nitens nymphs. In contrast, Rickettsia spp. was not detected in any of the 200 horse blood samples included in this study. DNA sequence data of the rickettsial 17 kDa antigen gene showed that Rickettsia amblyommatis was present in A. mixtum; and Rickettsia felis in D. nitens. This is the first report of R. felis in D. nitens in Cuba. The present study extends our knowledge of the potential vector spectrum and distribution of SFG rickettsiae pathogens in western Cuba.
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Affiliation(s)
- A A Díaz-Sánchez
- Centro Nacional de Sanidad Agropecuaria (CENSA), Carretera de Tapaste y Autopista Nacional, Apartado postal 10, San José de las Lajas, Mayabeque, 32700, Cuba
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - N B Chilton
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - L Roblejo-Arias
- Centro Nacional de Sanidad Agropecuaria (CENSA), Carretera de Tapaste y Autopista Nacional, Apartado postal 10, San José de las Lajas, Mayabeque, 32700, Cuba
| | - O Fonseca-Rodríguez
- Department of Epidemiology and Global Health, Umeå University, Umeå, 901 87, Sweden
| | - R Marrero-Perera
- Centro Nacional de Sanidad Agropecuaria (CENSA), Carretera de Tapaste y Autopista Nacional, Apartado postal 10, San José de las Lajas, Mayabeque, 32700, Cuba
| | - C P Diyes
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - M E M Yunik
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - E Lobo-Rivero
- Centro Nacional de Sanidad Agropecuaria (CENSA), Carretera de Tapaste y Autopista Nacional, Apartado postal 10, San José de las Lajas, Mayabeque, 32700, Cuba
| | - B Corona-González
- Centro Nacional de Sanidad Agropecuaria (CENSA), Carretera de Tapaste y Autopista Nacional, Apartado postal 10, San José de las Lajas, Mayabeque, 32700, Cuba
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Characteristics of in vitro infection of human monocytes, by Rickettsia helvetica. Microbes Infect 2020; 23:104776. [PMID: 33276122 DOI: 10.1016/j.micinf.2020.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/21/2020] [Accepted: 11/23/2020] [Indexed: 02/06/2023]
Abstract
Eighteen species of rickettsiae are reported to cause infections in humans. One of these is Rickettsia helvetica, which is endemic in European and Asian countries and transmitted by the tick Ixodes ricinus. Besides fever, it has been demonstrated to cause meningitis and is also associated with perimyocarditis. One of the initial targets for rickettsiae after inoculation by ticks is the macrophage/monocyte. How rickettsiae remain in the macrophages/monocytes before establishing their infection in vascular endothelial cells remains poorly understood. The main aim of the present study was to investigate the impact on and survival of R. helvetica in a human leukemic monocytic cell line, THP-1. Our results show that R. helvetica survives and propagates in the THP-1 cells. The infection in monocytes was followed for seven days by qPCR and for 30 days by TEM, where invasion of the nucleus was also observed as well as double membrane vacuoles containing rickettsiae, a finding suggesting that R. helvetica might induce autophagy at the early stage of infection. Infected monocytes induced TNF-α which may be important in host defence against rickettsial infections and promote cell survival and inhibiting cell death by apoptosis. The present findings illustrate the importance of monocytes to the pathogenesis of rickettsial disease.
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17
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Gaba S, Garg S, Gupta M, Gupta R. Haemorrhagic encephalitis in the garb of scrub typhus. BMJ Case Rep 2020; 13:13/8/e235790. [PMID: 32859623 DOI: 10.1136/bcr-2020-235790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 19-year-old girl presented with fever, headache, vomiting and drowsiness. She had grade 1 papilloedema and neck rigidity but no focal deficits or seizures. Cerebrospinal fluid analysis revealed lymphocytic pleocytosis, slightly elevated protein and normal glucose. MRI of the brain showed a hyperintense lesion in left ganglio-capsular region on the fluid attenuation inversion recovery sequence with perilesional oedema and mild midline shift. Haemorrhage was seen in the region on susceptibility weighted imaging . The patient was thoroughly investigated for known causes of meningoencephalitis, but the diagnosis of scrub typhus was delayed till the 10th day of illness. She was treated with doxycycline for 2 weeks and had marked improvement, both clinically and radiologically. Literature review has revealed that although meningoencephalitis in scrub typhus is not uncommon, such atypical lesions on brain MRI are a rarity. Serial imaging was performed to document the disease progression and resolution on treatment.
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Affiliation(s)
- Saurabh Gaba
- Department of General Medicine, Government Medical College and Hospital, Chandigarh, India
| | - Swati Garg
- Department of General Medicine, Government Medical College and Hospital, Chandigarh, India
| | - Monica Gupta
- Department of General Medicine, Government Medical College and Hospital, Chandigarh, India
| | - Rekha Gupta
- Department of Radiodiagnosis, Government Medical College and Hospital, Chandigarh, India
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18
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Al-Deeb MA, Muzaffar SB. Prevalence, distribution on host's body, and chemical control of camel ticks Hyalomma dromedarii in the United Arab Emirates. Vet World 2020; 13:114-120. [PMID: 32158160 PMCID: PMC7020109 DOI: 10.14202/vetworld.2020.114-120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/06/2019] [Indexed: 12/19/2022] Open
Abstract
Background and Aim Camel farming remains a part of the culture of the Arabian Peninsula although modern methods have greatly increased camel densities in the entire region. In the United Arab Emirates (UAE), camel production is threatened by tick parasitism. However, no study has considered assessing the magnitude of the problem in the UAE. We conducted a study evaluating tick richness, abundance, and spatial distribution of ticks on camels in farms near Al Ain, UAE. In addition, we conducted a survey of farm owners to determine the control methods used to eliminate camel ticks. Materials and Methods Tick counts were made on 502 camels (Camelus dromedarius). For each examined animal, visual counts of ticks were made on the entire body segregating the counts by head, neck, forelegs, hump, abdomen, back legs, and tail area. In addition, a total of 70 camel owners from the study area were randomly selected and surveyed about the tick control methods. Results Hyalomma dromedarii was the only species found during the study. The prevalence of ticks was 98% among the sampled animals. The mean intensity (tick load) was 25.8±2.4 ticks/host and the maximum number of ticks per animal was 102. Ticks were found in five vicinities that are on the border with Oman. The highest number of ticks on the body of the camel occurred on the tail area followed by the abdomen. Cypermethrin was the most commonly used acaricide (46.9%). Conclusion The high abundance of ticks reported in this study calls for the establishment of a good management strategy. In addition, finding ticks in vicinities in the UAE that are on the border with Oman suggests a cross-border movement between the two countries. Therefore, studying this movement is important to understand its role in the global circulation of some H. dromedarii tick-borne diseases and the movement of acaricide resistance alleles among tick populations.
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Affiliation(s)
- Mohammad Ali Al-Deeb
- Department of Biology, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Sabir Bin Muzaffar
- Department of Biology, United Arab Emirates University, Al Ain, United Arab Emirates
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19
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Quantitative Proteomics of the Endothelial Secretome Identifies RC0497 as Diagnostic of Acute Rickettsial Spotted Fever Infections. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:306-322. [PMID: 31955791 DOI: 10.1016/j.ajpath.2019.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/28/2019] [Accepted: 10/03/2019] [Indexed: 12/29/2022]
Abstract
Mediterranean spotted fever is a reemerging acute tick-borne infection produced by the α-proteobacterium, Rickettsia conorii. Rickettsia conorii infects vascular endothelial cells producing disseminated plasma leakage, manifesting as nonspecific fever, headache, and maculopapular rash. Because there are no available tests of early infection, Mediterranean spotted fever is often undiagnosed and untreated, resulting in significant mortality. To address this critical need, we have applied a quantitative proteomics pipeline for analyzing the secretome of primary human umbilical vein endothelial cells. Of the 104 proteins whose abundance changed significantly in the R. conorii-infected human umbilical vein endothelial cells' secretome, 46 proteins were up-regulated: 45 were host secreted proteins (including cytokines), and 1 was a rickettsial protein, the putative N-acetylmuramoyl-l-alanine amidase RC0497. Proteins with sequence highly homologous to RC0497 were found to be shared by many species of the spotted fever group rickettsiae, but not typhus group rickettsiae. Quantitative targeted proteomics studies of plasma from a mouse model of sublethal and lethal R. conorii identified RC0497 in the blood, and its circulating levels were proportionally associated with infection outcome. Finally, the presence of RC0497 in the serum samples from a cohort of humans presenting with acute rickettsioses was confirmed. The detection of RC0497 has the potential to be a sensitive and specific marker for acute rickettsial spotted rickettsioses.
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20
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Ray A, Mohta S, Soneja M, Jadon R, Wig N, Sood R. Clinical spectrum and outcome of critically ill hospitalized patients with acute febrile illness and new-onset organ dysfunction presenting during monsoon season. Drug Discov Ther 2019; 13:101-107. [PMID: 31080200 DOI: 10.5582/ddt.2019.01023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Acute febrile illness (AFI) is one of the commonest indications for hospitalization and can present with varying severity including single or multiple organ dysfunction syndrome (MODS). During monsoon season, there is a spurt of AFI often caused by vector borne diseases leading to substantial morbidity and mortality. Our aim was to determine distribution of etiological causes, differential organ involvement and predictors of mortality in critically ill patients with AFI. It was a hospital based observational study which included patients with AFI with dysfunction of at least one organ system. The study was conducted over 4 months during monsoon season. Admitted patients were included who had been subjected to a standard battery of tests and managed with standard hospital based management protocol. 145 patients were included and etiology of fever was ascertained in 81.4% of patients with the most common single infection being chikungunya (20.7%) followed by dengue (20%) fever. Thrombocytopenia and deranged liver biochemistry each were seen in nearly 75% of the patients. Renal (50.3%) and nervous system (46.2%) dysfunction were the predominant organ failures. 49 patients died (33.8%) which correlated with predicted mortality by APACHE (acute physiological assessment and chronic health evaluation) II score. Independent predictors for mortality were older age (> 55 years) (p = 0.01), acidemia (p = 0.01), altered sensorium (p = 0.02) and coagulopathy (p = 0.048). Sub-group analysis revealed that amongst patients with MODS, hypotension could help differentiate between bacterial and non-bacterial causes (p = 0.01). Critically ill patients with AFI suffer from significant morbidity and mortality. Features like the presence of hypotension in MODS may differentiate between a bacterial cause vis-à-vis viral or protozoal etiology.
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Affiliation(s)
- Animesh Ray
- Department of Medicine, All India Institute of Medical Sciences
| | - Srikant Mohta
- Department of Medicine, All India Institute of Medical Sciences
| | - Manish Soneja
- Department of Medicine, All India Institute of Medical Sciences
| | - Ranveer Jadon
- Department of Medicine, All India Institute of Medical Sciences
| | - Naveet Wig
- Department of Medicine, All India Institute of Medical Sciences
| | - Rita Sood
- Department of Medicine, All India Institute of Medical Sciences
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21
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Sekeyová Z, Danchenko M, Filipčík P, Fournier PE. Rickettsial infections of the central nervous system. PLoS Negl Trop Dis 2019; 13:e0007469. [PMID: 31465452 PMCID: PMC6715168 DOI: 10.1371/journal.pntd.0007469] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
As a result of migrations and globalization, people may face a possible increase in the incidence of central nervous system rickettsial infections (CNS R). These diseases, caused by Rickettsia species and transmitted to humans by arthropod bites, are putatively lethal. However, the diagnosis of CNS R is challenging and often delayed due to their nonspecific clinical presentation and the strict intracellular nature of rickettsiae. Furthermore, transfer of rickettsiae to the brain parenchyma is not yet understood. The aim of this review is to analyze and summarize the features and correlated findings of CNS R in order to focus attention on these intriguing but frequently neglected illnesses. We also incorporated data on CNS infections caused by Rickettsia-related microorganisms.
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Affiliation(s)
- Zuzana Sekeyová
- Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Monika Danchenko
- Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Peter Filipčík
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Pierre Edouard Fournier
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU Mediterranée-Infection, Marseille, France
- Centre National de Référence des Rickettsia, Coxiella et Bartonella, IHU Mediterranée-Infection, Marseille, France
- * E-mail:
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22
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Abstract
A wide variety of pathogens reach the circulatory system during viral, parasitic, fungal, and bacterial infections, causing clinically diverse pathologies. Such systemic infections are usually severe and frequently life-threatening despite intensive care, in particular during the age of antibiotic resistance. Because of its position at the interface between the blood and the rest of the organism, the endothelium plays a central role during these infections. Using several examples of systemic infections, we explore the diversity of interactions between pathogens and the endothelium. These examples reveal that bacterial pathogens target specific vascular beds and affect most aspects of endothelial cell biology, ranging from cellular junction stability to endothelial cell proliferation and inflammation.
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Esteves E, Bizzarro B, Costa FB, Ramírez-Hernández A, Peti APF, Cataneo AHD, Wowk PF, Timóteo RP, Labruna MB, Silva Junior PI, Silva CL, Faccioli LH, Fogaça AC, Sorgi CA, Sá-Nunes A. Amblyomma sculptum Salivary PGE 2 Modulates the Dendritic Cell- Rickettsia rickettsii Interactions in vitro and in vivo. Front Immunol 2019; 10:118. [PMID: 30778355 PMCID: PMC6369204 DOI: 10.3389/fimmu.2019.00118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/15/2019] [Indexed: 01/06/2023] Open
Abstract
Amblyomma sculptum is an important vector of Rickettsia rickettsii, causative agent of Rocky Mountain spotted fever and the most lethal tick-borne pathogen affecting humans. To feed on the vertebrate host's blood, A. sculptum secretes a salivary mixture, which may interact with skin resident dendritic cells (DCs) and modulate their function. The present work was aimed at depicting the A. sculptum saliva-host DC network and the biochemical nature of the immunomodulatory component(s) involved in this interface. A. sculptum saliva inhibits the production of inflammatory cytokines by murine DCs stimulated with LPS. The fractionation of the low molecular weight salivary content by reversed-phase chromatography revealed active fractions eluting from 49 to 55% of the acetonitrile gradient. Previous studies suggested that this pattern of elution matches with that observed for prostaglandin E2 (PGE2) and the molecular identity of this lipid mediator was unambiguously confirmed by a new high-resolution mass spectrometry methodology. A productive infection of murine DCs by R. rickettsii was demonstrated for the first time leading to proinflammatory cytokine production that was inhibited by both A. sculptum saliva and PGE2, a result also achieved with human DCs. The adoptive transfer of murine DCs incubated with R. rickettsii followed by treatment with A. sculptum saliva or PGE2 did not change the cytokine profile associated to cellular recall responses while IgG2a-specific antibodies were decreased in the serum of these mice. Together, these findings emphasize the role of PGE2 as a universal immunomodulator of tick saliva. In addition, it contributes to new approaches to explore R. rickettsii-DC interactions both in vitro and in vivo.
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Affiliation(s)
- Eliane Esteves
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Bruna Bizzarro
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Francisco Borges Costa
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Alejandro Ramírez-Hernández
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Ana Paula Ferranti Peti
- Department of Clinical Analysis, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil
| | | | - Pryscilla Fanini Wowk
- Laboratory of Molecular Virology, Carlos Chagas Institute, Fundação Oswaldo Cruz, Curitiba, Brazil
| | - Rodolfo Pessato Timóteo
- Institute of Natural and Biological Sciences, Federal University of Triângulo Mineiro, Uberaba, Brazil
| | - Marcelo Bahia Labruna
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | | | - Célio Lopes Silva
- Department of Biochemistry and Immunology, School of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil
| | - Lúcia Helena Faccioli
- Department of Clinical Analysis, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil
| | - Andréa Cristina Fogaça
- Department de Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,National Institute of Science and Technology in Molecular Entomology, National Council of Scientific and Technological Development (INCT-EM/CNPq), Rio de Janeiro, Brazil
| | - Carlos Arterio Sorgi
- Department of Clinical Analysis, Toxicology and Food Science, School of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirao Preto, Brazil
| | - Anderson Sá-Nunes
- Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,National Institute of Science and Technology in Molecular Entomology, National Council of Scientific and Technological Development (INCT-EM/CNPq), Rio de Janeiro, Brazil
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24
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Prudent E, Raoult D. Fluorescence in situ hybridization, a complementary molecular tool for the clinical diagnosis of infectious diseases by intracellular and fastidious bacteria. FEMS Microbiol Rev 2018; 43:88-107. [DOI: 10.1093/femsre/fuy040] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 11/07/2018] [Indexed: 12/16/2022] Open
Affiliation(s)
- Elsa Prudent
- Aix Marseille Université, IRD, APHM, MEPHI, IHU-Méditerranée Infection, 19–21 Boulevard Jean Moulin, 13005 Marseille, France
| | - Didier Raoult
- Aix Marseille Université, IRD, APHM, MEPHI, IHU-Méditerranée Infection, 19–21 Boulevard Jean Moulin, 13005 Marseille, France
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vWA proteins of Leptospira interrogans induce hemorrhage in leptospirosis by competitive inhibition of vWF/GPIb-mediated platelet aggregation. EBioMedicine 2018; 37:428-441. [PMID: 30337247 PMCID: PMC6284457 DOI: 10.1016/j.ebiom.2018.10.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/10/2018] [Accepted: 10/10/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUD Leptospira interrogans is the major causative agent of leptospirosis, a worldwide zoonotic disease. Hemorrhage is a typical pathological feature of leptospirosis. Binding of von Willebrand factor (vWF) to platelet glycoprotein-Ibα (GPIbα) is a crucial step in initiation of platelet aggregation. The products of L. interrogans vwa-I and vwa-II genes contain vWF-A domains, but their ability to induce hemorrhage has not been determined. METHODS Human (Hu)-platelet- and Hu-GPIbα-binding abilities of the recombinant proteins expressed by L. interrogans strain Lai vwa-I and vwa-II genes (rLep-vWA-I and rLep-vWA-II) were detected by flowcytometry, surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). Hu-platelet aggregation and its signaling kinases and active components were detected by lumiaggregometry, Western analysis, spectrophotometry and confocal microscopy. Hu-GPIbα-binding sites in rLep-vWA-I and rLep-vWA-II were identified by SPR/ITC measurements. FINDINGS Both rLep-vWA-I and rLep-vWA-II were able to bind to Hu-platelets and inhibit rHu-vWF/ristocetin-induced Hu-platelet aggregation, but Hu-GPIbα-IgG, rLep-vWA-I-IgG and rLep-vWA-II-IgG blocked this binding or inhibition. SPR and ITC revealed a tight interaction between Hu-GPIbα and rLep-vWA-I/rLep-vWA-II with KD values of 3.87 × 10-7-8.65 × 10-8 M. Hu-GPIbα-binding of rL-vWA-I/rL-vWA-II neither activated the PI3K/AKT-ERK and PLC/PKC kinases nor affected the NO, cGMP, ADP, Ca2+ and TXA2 levels in Hu-platelets. G13/R36/G47 in Lep-vWA-I and G76/Q126 in Lep-vWA-II were confirmed as the Hu-GPIbα-binding sites. Injection of rLep-vWA-I or rLep-vWA-II in mice resulted in diffuse pulmonary and focal renal hemorrhage but this hemorrhage was blocked by rLep-vWA-I-IgG or rLep-vWA-II-IgG. INTERPRETATION The products of L. interrogans vwa-I and vwa-II genes induce hemorrhage by competitive inhibition of vWF-mediated Hu-platelet aggregation.
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Magaz Martínez M, Ramos A, Masegosa J, Abreu L. Rickettsia conorii: Unusual cause of diarrhoea. GASTROENTEROLOGIA Y HEPATOLOGIA 2018; 41:165-166. [PMID: 28427729 DOI: 10.1016/j.gastrohep.2017.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Marta Magaz Martínez
- Aparato Digestivo, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda, Madrid, España.
| | - Antonio Ramos
- Unidad de Infecciosas, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda, Madrid, España
| | - Jose Masegosa
- Aparato Digestivo, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda, Madrid, España
| | - Luis Abreu
- Aparato Digestivo, Hospital Universitario Puerta de Hierro-Majadahonda, Majadahonda, Madrid, España
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Ayachit A, Ayachit G, Joshi S, Sameera VV. Commentary: Rickettsial retinitis - Direct bacterial infection or an immune-mediated response? Indian J Ophthalmol 2017; 65:1041-1043. [PMID: 29044083 PMCID: PMC5678311 DOI: 10.4103/ijo.ijo_681_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Apoorva Ayachit
- Department of Vitreoretina, M M Joshi Eye Institute, Hubli, Karnataka, India
| | - Guruprasad Ayachit
- Department of Vitreoretina, M M Joshi Eye Institute, Hubli, Karnataka, India
| | - Shrinivas Joshi
- Department of Vitreoretina, M M Joshi Eye Institute, Hubli, Karnataka, India
| | - V V Sameera
- Department of Vitreoretina, M M Joshi Eye Institute, Hubli, Karnataka, India
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Seroprevalence against Rickettsia and Borrelia Species in Patients with Uveitis: A Prospective Survey. J Ophthalmol 2017; 2017:9247465. [PMID: 29318041 PMCID: PMC5727782 DOI: 10.1155/2017/9247465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 10/01/2017] [Accepted: 10/30/2017] [Indexed: 11/18/2022] Open
Abstract
Vector-borne diseases such as Lyme borreliosis and rickettsioses have been associated with ocular inflammation. Our aim was to study patients with diagnosed uveitis to evaluate serological signs of infection or exposure to these tick-borne agents. Forty-eight patients were prospectively examined with serology together with medical records and a questionnaire concerning previous exposure, diseases, and treatments. Seven patients (14.6%) showed seroconversion to Rickettsia spp. between acute and convalescent phase sera, which provides support for a positive Rickettsia diagnosis according to guidelines. The specificity was confirmed by Western blot. Additional 28 patients had stationary titres of which eight (16.6%) had 1 : 256 or higher titre in the first serum, and another 13 patients were seronegative. No epidemiological risk factor or marker could be identified. For Borrelia, only three patients showed moderate IgG titres. A control group of 100 blood donors, 60 patients with rheumatic disease, and 56 patients seeking medical care were tested of which 2.0–7.1% showed low anti-Rickettsia titres and 3.0–8.3% anti-Borrelia titres. The findings are indicative for an association between infection or exposure to Rickettsia spp. and uveitis with a seropositivity among patients with recurrent uveitis in concordance with the spread of rickettsial exposure in a tick-exposed population.
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Evaluation of changes to the Rickettsia rickettsii transcriptome during mammalian infection. PLoS One 2017; 12:e0182290. [PMID: 28832688 PMCID: PMC5568294 DOI: 10.1371/journal.pone.0182290] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/14/2017] [Indexed: 12/12/2022] Open
Abstract
The lifecycle of Rickettsia rickettsii includes infection of both mammalian and arthropod hosts, with each environment presenting distinct challenges to survival. As such, these pathogens likely have distinctive transcriptional strategies for infection of each host. Herein, we report the utilization of next generation sequencing (RNAseq) and bioinformatic analysis techniques to examine the global transcriptional profile of R. rickettsii within an infected animal, and to compare that data to transcription in tissue culture. The results demonstrate substantial R. rickettsii transcriptional alteration in vivo, such that the bacteria are considerably altered from cell culture. Identification of significant transcriptional changes and validation of RNAseq by quantitative PCR are described with particular emphasis on known antigens and suspected virulence factors. Together, these results suggest that transcriptional regulation of a distinct cohort of genes may contribute to successful mammalian infection.
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Budachetri K, Kumar D, Karim S. Catalase is a determinant of the colonization and transovarial transmission of Rickettsia parkeri in the Gulf Coast tick Amblyomma maculatum. INSECT MOLECULAR BIOLOGY 2017; 26:414-419. [PMID: 28370634 PMCID: PMC5496812 DOI: 10.1111/imb.12304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Gulf Coast tick (Amblyomma maculatum) has evolved as a competent vector of the spotted-fever group rickettsia, Rickettsia parkeri. In this study, the functional role of catalase, an enzyme responsible for the degradation of toxic hydrogen peroxide, in the colonization of the tick vector by R. parkeri and transovarial transmission of this pathogen to the next tick generation, was investigated. Catalase gene (CAT) expression in midgut, salivary glands and ovarian tissues exhibited a 2-11-fold increase in transcription level upon R. parkeri infection. Depletion of CAT transcripts using an RNA-interference approach significantly reduced R. parkeri infection levels in midgut and salivary gland tissues by 53-63%. The role of CAT in transovarial transmission of R. parkeri was confirmed by simultaneously blocking the transcript and the enzyme by injecting double-stranded RNA for CAT and a catalase inhibitor (3-amino-1,2,4-triazole) into gravid females. Simultaneous inhibition of the CAT transcript and the enzyme significantly reduced the egg conversion ratio with a 44% reduction of R. parkeri transovarial transmission. These data suggest that catalase is required for rickettsial colonization of the tick vector and transovarial transmission to the next generation.
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Tull R, Ahn C, Daniel A, Yosipovitch G, Strowd LC. Retrospective Study of Rocky Mountain Spotted Fever in Children. Pediatr Dermatol 2017; 34:119-123. [PMID: 27990680 DOI: 10.1111/pde.13053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND/OBJECTIVES Rocky Mountain spotted fever (RMSF), a lethal tick-borne illness, is prevalent in the south central United States. Children younger than 10 years old have the greatest risk of fatal outcome from RMSF. The objective of the current study was to review pediatric cases of RMSF seen in the dermatology consult service and to evaluate dermatology's role in the diagnosis and management of this disease. METHODS A retrospective review was performed of inpatient dermatology consultations at a tertiary care center in North Carolina from 2001 to 2011. Data collected included patient demographic characteristics, symptoms, pre- and postconsultation diagnoses, diagnostic procedures, length of hospital stay, and outcome. RESULTS A total of 3,912 consultations were conducted in the dermatology service over 10 years. Six patients with RMSF, ranging in age from 22 months to 10 years (mean 5.1 years), were evaluated during April, May, and June. All preconsultation diagnoses included RMSF in the differential diagnosis. All patients underwent skin biopsies, and a culture was obtained in one case. Fifty percent of patients died within 4 days of hospitalization. CONCLUSIONS Variables associated with mortality from RMSF are delayed diagnosis and initiation of antirickettsial therapy. Physicians should consider RMSF in children presenting with fever and rash during the summer months. Dermatology consultation is useful in evaluating patients with suspicious clinical features of RMSF with skin findings.
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Affiliation(s)
- Rechelle Tull
- Department of Dermatology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Christine Ahn
- Department of Dermatology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina
| | - Alyssa Daniel
- Mecklenburg Medical Group-Southpark, Charlotte, North Carolina
| | - Gil Yosipovitch
- Department of Dermatology, School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Lindsay C Strowd
- Department of Dermatology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina
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Papp S, Rauch J, Kuehl S, Richardt U, Keller C, Osterloh A. Comparative evaluation of two Rickettsia typhi-specific quantitative real-time PCRs for research and diagnostic purposes. Med Microbiol Immunol 2016; 206:41-51. [PMID: 27696011 DOI: 10.1007/s00430-016-0480-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 09/21/2016] [Indexed: 01/03/2023]
Abstract
Rickettsioses are caused by intracellular bacteria of the family of Rickettsiaceae. Rickettsia (R.) typhi is the causative agent of endemic typhus. The disease occurs worldwide and is one of the most prevalent rickettsioses. Rickettsial diseases, however, are generally underdiagnosed which is mainly due to the lack of sensitive and specific methods. In addition, methods for quantitative detection of the bacteria for research purposes are rare. We established two qPCRs for the detection of R. typhi by amplification of the outer membrane protein B (ompB) and parvulin-type PPIase (prsA) genes. Both qPCRs are specific and exclusively recognize R. typhi but no other rickettsiae including the closest relative, R. prowazekii. The prsA-based qPCR revealed to be much more sensitive than the amplification of ompB and provided highly reproducible results in the detection of R. typhi in organs of infected mice. Furthermore, as a nested PCR the prsA qPCR was applicable for the detection of R. typhi in human blood samples. Collectively, the prsA-based qPCR represents a reliable method for the quantitative detection of R. typhi for research purposes and is a promising candidate for differential diagnosis.
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Affiliation(s)
- Stefanie Papp
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Jessica Rauch
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Svenja Kuehl
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Ulricke Richardt
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany
| | - Christian Keller
- Institute for Virology, University Medical Center Gießen and Marburg, 35032, Marburg, Germany
| | - Anke Osterloh
- Department of Immunology, Bernhard Nocht Institute for Tropical Medicine, 20359, Hamburg, Germany.
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Dzelalija B, Punda-Polic V, Medic A, Dobec M. Rickettsiae and rickettsial diseases in Croatia: Implications for travel medicine. Travel Med Infect Dis 2016; 14:436-443. [PMID: 27404664 DOI: 10.1016/j.tmaid.2016.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/30/2016] [Accepted: 06/30/2016] [Indexed: 11/28/2022]
Abstract
AIM To review the current state of knowledge concerning rickettsiae and rickettsioses in Croatia and to discuss their implications for travellers. METHODS The PubMed database was searched from 1991 to 2015 by combining the words "rickettsia," "rickettsiosis", "travellers" and "Croatia". RESULTS Since 1969, Croatia appears to be free of epidemic typhus (ET) caused by Rickettsia prowazekii and the last case of Brill-Zinsser disease was recorded in 2008. Mediterranean spotted fever (MSF) caused by Rickettsia conorii is the most frequent human rickettsial infection in Croatia, followed by murine typhus caused by Rickettsia typhi. Human cases of MSF and murine typhus have been predominantly observed along the eastern Adriatic coast from Zadar to Dubrovnik and between Zadar and Split, respectively. Rickettsia akari, etiologic agent of rickettsialpox, was isolated from blood of a patient diagnosed with MSF in Zadar, but no cases of rickettsialpox were reported. Several species of pathogenic (Rickettsia slovaca, Rickettsia aeschlimannii, Ricketsia helvetica, and Ricketsia raoultii) and species of undetermined pathogenicity (Ricketsia hoogstraalii sp. nov.) rickettsiae were identified in ticks collected in different ecological regions of Croatia. A search of the literature revealed no evidence of rickettsial infection in travellers visiting Croatia. Three imported cases of Rickettsia africae were observed in travellers returning from South Africa. CONCLUSION Rickettsiae and rickettsial diseases continue to be present in Croatia. As they can be acquired while travelling, physicians should consider rickettsial infection in the differential diagnosis of patients returning from Croatia and presenting with febrile illness.
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Affiliation(s)
- Boris Dzelalija
- Department of Infectious Diseases, Zadar General Hospital, Zadar, Croatia; School of Medicine, University of Split, Split, Croatia
| | | | - Alan Medic
- Institute of Public Health, Zadar, Croatia
| | - Marinko Dobec
- Medica, Medizinische Laboratorien Dr. F. Kaeppeli, Wolfbachstrasse 17, CH-8024 Zurich, Switzerland.
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Zhao Y, Valbuena G, Walker DH, Gazi M, Hidalgo M, DeSousa R, Oteo JA, Goez Y, Brasier AR. Endothelial Cell Proteomic Response to Rickettsia conorii Infection Reveals Activation of the Janus Kinase (JAK)-Signal Transducer and Activator of Transcription (STAT)-Inferferon Stimulated Gene (ISG)15 Pathway and Reprogramming Plasma Membrane Integrin/Cadherin Signaling. Mol Cell Proteomics 2015; 15:289-304. [PMID: 26560068 DOI: 10.1074/mcp.m115.054361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Indexed: 11/06/2022] Open
Abstract
Rickettsia conorii is the etiologic agent of Mediterranean spotted fever, a re-emerging infectious disease with significant mortality. This Gram-negative, obligately intracellular pathogen is transmitted via tick bites, resulting in disseminated vascular endothelial cell infection with vascular leakage. In the infected human, Rickettsia conorii infects endothelial cells, stimulating expression of cytokines and pro-coagulant factors. However, the integrated proteomic response of human endothelial cells to R. conorii infection is not known. In this study, we performed quantitative proteomic profiling of primary human umbilical vein endothelial cells (HUVECs) with established R conorii infection versus those stimulated with endotoxin (LPS) alone. We observed differential expression of 55 proteins in HUVEC whole cell lysates. Of these, we observed induction of signal transducer and activator of transcription (STAT)1, MX dynamin-like GTPase (MX1), and ISG15 ubiquitin-like modifier, indicating activation of the JAK-STAT signaling pathway occurs in R. conorii-infected HUVECs. The down-regulated proteins included those involved in the pyrimidine and arginine biosynthetic pathways. A highly specific biotinylated cross-linking enrichment protocol was performed to identify dysregulation of 11 integral plasma membrane proteins that included up-regulated expression of a sodium/potassium transporter and down-regulation of α-actin 1. Analysis of Golgi and soluble Golgi fractions identified up-regulated proteins involved in platelet-endothelial adhesion, phospholipase activity, and IFN activity. Thirty four rickettsial proteins were identified with high confidence in the Golgi, plasma membrane, or secreted protein fractions. The host proteins associated with rickettsial infections indicate activation of interferon-STAT signaling pathways; the disruption of cellular adhesion and alteration of antigen presentation pathways in response to rickettsial infections are distinct from those produced by nonspecific LPS stimulation. These patterns of differentially expressed proteins suggest mechanisms of pathogenesis as well as methods for diagnosis and monitoring Rickettsia infections.
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Affiliation(s)
- Yingxin Zhao
- From the Departments of ‡Internal Medicine and §Institute for Translational Sciences, and ¶Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas 77555-1060
| | | | | | | | - Marylin Hidalgo
- the **Microbiology Department, Faculty of Sciences, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Rita DeSousa
- the ‡‡Centre for the Study of Vectors and Infectious Diseases Dr. Francisco Cambournac, National Institute of Health Dr. Ricardo Jorge, Águas de Moura, Av. Padre Cruz, Lisbon, 1649-016, Portugal, and
| | - Jose Antonio Oteo
- the §§Centre of Rickettsiosis and Arthropod-Borne Diseases, Hospital San Pedro-Centro de Investigation Biomedical de la Rioja (CIBIR), Logroño, La Rioja, 26006, Spain
| | | | - Allan R Brasier
- From the Departments of ‡Internal Medicine and §Institute for Translational Sciences, and ¶Sealy Center for Molecular Medicine, University of Texas Medical Branch, Galveston, Texas 77555-1060,
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Wang J, Dyachenko V, Munderloh UG, Straubinger RK. Transmission of Anaplasma phagocytophilum from endothelial cells to peripheral granulocytes in vitro under shear flow conditions. Med Microbiol Immunol 2015; 204:593-603. [PMID: 25618174 DOI: 10.1007/s00430-015-0387-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/13/2015] [Indexed: 01/06/2023]
Abstract
Anaplasma phagocytophilum (Ap) is a tick-borne pathogen, which can cause granulocytic anaplasmosis in humans and animals. In vivo this obligate intracellular pathogen is primarily located in circulating mature granulocytes, but it also infects endothelial cells. In order to study the interaction between Ap-infected endothelial cells and human granulocytes under conditions similar to those found naturally in the infected host, an in vitro model that mimics physiological flow conditions in the microvasculature was established. Cell-to-cell interactions were then visualized by microscopy, which showed that granulocytes adhered strongly to Ap-infected endothelial cells at a shear stress of 0.5 dyne/cm(2). In addition, Ap-transmission assays under flow conditions showed that the bacteria transferred from infected endothelial cells to circulating granulocytes and were able to establish infection in constantly moving granulocytes. Cell surface analysis showed that Ap induced up-regulation of the cell adhesion molecules ICAM-1 and VCAM-1 on infected endothelial cells in a dose-dependent manner. Furthermore, IL-8 secretion by endothelial cells indicated that the presence of Ap induced a pro-inflammatory response. In summary, the results of this study suggest that endothelial cells of the microvasculature (1) provide an excellent site for Ap dissemination to peripheral blood granulocytes under flow conditions and therefore may play a crucial role in the development of persistent infection, and (2) are stimulated by Ap to express surface molecules and cytokines that may lead to inflammatory responses at the site of the infection.
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Affiliation(s)
- Jinyong Wang
- Institute for Infectious Diseases and Zoonoses, Department of Veterinary Sciences, Faculty of Veterinary Medicine, LMU Munich, Veterinärstr. 13, 80539, Munich, Germany
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La Manna MP, Torina A, Agnone A, Blanda V, Caracappa S, Alongi A, Di Marco V, Giudice E, Dieli F, Sireci G. Detection of natural killer T cells in mice infected with Rickettsia conorii. Transbound Emerg Dis 2014; 60 Suppl 2:80-5. [PMID: 24589105 DOI: 10.1111/tbed.12143] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Indexed: 10/26/2022]
Abstract
Little information is available regarding the role of natural killer T (NKT) cells during the early stage of Rickettsia conorii infection. Herein, C3H/HeN mice were infected with the Malish 7 strain of R. conorii. Splenocytes from these mice were analysed in the early stage of the infection by flow cytometry and compared with uninfected controls. Our results showed an increase in NKT cells in infected mice. Additionally, NKT interleukin (IL)-17(+) cells increased three days after infection, together with a concurrent decrease in the relative amount of NKT interferon (IFN)-γ(+) cells. We also confirmed a higher amount of NK IFN-γ(+) cells in infected mice. Taken together, our data showed that NKT cells producing Il-17 increased during the early stage of rickettsial infection. These results suggest a connection between IL-17(+) NKT cells and vasculitis, which is the main clinical symptom of rickettsiosis.
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Hanna J, O'Gorman P, Neill J, Chaudhuri A, Hamilton-Craig C, West M. Rickettsia-related acute myocardial infarction in a patient with angiographically normal coronary arteries. Int J Cardiol 2014; 172:e346-7. [DOI: 10.1016/j.ijcard.2013.12.307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 12/30/2013] [Indexed: 10/25/2022]
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Minniear TD, Buckingham SC. Managing Rocky Mountain spotted fever. Expert Rev Anti Infect Ther 2014; 7:1131-7. [DOI: 10.1586/eri.09.94] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Walker D. Interactions of Pathogens with the Host. PATHOBIOLOGY OF HUMAN DISEASE 2014. [PMCID: PMC7173434 DOI: 10.1016/b978-0-12-386456-7.01701-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infection occurs when a microbe enters a normally nonsterile tissue and may cause an infectious disease with signs and symptoms or a subclinical infection. Infections that are not cleared by the host are characterized as persistent. The agent in nonreplicating or latent infection may begin to grow again or to reactivate. Growth of a microorganism such as normal bacterial flora on a normally nonsterile body surface such as the colonic mucosa in the absence of disease is called colonization. Some infectious agents known as pathogens routinely cause disease; others known as opportunistic cause disease only in persons with altered host defenses, such as acquired immunodeficiency syndrome. The location where a pathogen normally resides is the reservoir, such as naturally infected animals. The mechanism by which the pathogen moves from the reservoir into the patient is known as transmission such as by drinking contaminated water. The portals of entry are mucosal, respiratory, gastrointestinal, genitourinary, and cutaneous. A pathogen may replicate at the portal of entry and cause disease by secreting a toxin or enter the body and spread via the lymphatic or blood vessels, nerves, urinary tract, respiratory tract, cerebrospinal fluid, over mesothelial surfaces, or to the fetus transplacentally. Many infectious agents target a particular organ where they replicate and cause damage, for example, hepatitis, myocarditis, and meningoencephalitis.
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Carvalho YBM, Poersch LH, Romano LA. Rickettsia-Associated Mortality of the Yellow ClamMesodesma mactroides(Bivalvia: Mesodesmatidae) in Southern Brazil. MALACOLOGIA 2013. [DOI: 10.4002/040.056.0217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Qi Y, Xiong X, Duan C, Jiao J, Gong W, Wen B. Recombinant protein YbgF induces protective immunity against Rickettsia heilongjiangensis infection in C3H/HeN mice. Vaccine 2013; 31:5643-50. [DOI: 10.1016/j.vaccine.2013.09.064] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/12/2013] [Accepted: 09/27/2013] [Indexed: 10/26/2022]
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Johnson B, Selle K, O'Flaherty S, Goh YJ, Klaenhammer T. Identification of extracellular surface-layer associated proteins in Lactobacillus acidophilus NCFM. MICROBIOLOGY-SGM 2013; 159:2269-2282. [PMID: 24002751 PMCID: PMC3836491 DOI: 10.1099/mic.0.070755-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bacterial surface (S-) layers are crystalline arrays of self-assembling, proteinaceous subunits called S-layer proteins (Slps), with molecular masses ranging from 40 to 200 kDa. The S-layer-forming bacterium Lactobacillus acidophilus NCFM expresses three major Slps: SlpA (46 kDa), SlpB (47 kDa) and SlpX (51 kDa). SlpA has a demonstrated role in adhesion to Caco-2 intestinal epithelial cells in vitro, and has been shown to modulate dendritic cell (DC) and T-cell functionalities with murine DCs. In this study, a modification of a standard lithium chloride S-layer extraction revealed 37 proteins were solubilized from the S-layer wash fraction. Of these, 30 have predicted cleavage sites for secretion, 24 are predicted to be extracellular, six are lipid-anchored, three have N-terminal hydrophobic membrane spanning regions and four are intracellular, potentially moonlighting proteins. Some of these proteins, designated S-layer associated proteins (SLAPs), may be loosely associated with or embedded within the bacterial S-layer complex. Lba-1029, a putative SLAP gene, was deleted from the chromosome of L. acidophilus. Phenotypic characterization of the deletion mutant demonstrated that the SLAP LBA1029 contributes to a pro-inflammatory TNF-α response from murine DCs. This study identified extracellular proteins and putative SLAPs of L. acidophilus NCFM using LC-MS/MS. SLAPs appear to impart important surface display features and immunological properties to microbes that are coated by S-layers.
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Affiliation(s)
- Brant Johnson
- Department of Microbiology, North Carolina State University, Raleigh, NC, USA
| | - Kurt Selle
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA
| | - Sarah O'Flaherty
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA
| | - Yong Jun Goh
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA
| | - Todd Klaenhammer
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, USA.,Department of Microbiology, North Carolina State University, Raleigh, NC, USA
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Sfar N, M'Ghirbi Y, Letaïef A, Parola P, Bouattour A, Raoult D. First report ofRickettsia monacensisandRickettsia helveticafrom Tunisia. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2013; 102:561-4. [DOI: 10.1179/136485908x311795] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Gong B, Lee YS, Lee I, Shelite TR, Kunkeaw N, Xu G, Lee K, Jeon SH, Johnson BH, Chang Q, Ha T, Mendell NL, Cheng X, Bouyer DH, Boor PJ, Ksiazek TG, Walker DH. Compartmentalized, functional role of angiogenin during spotted fever group rickettsia-induced endothelial barrier dysfunction: evidence of possible mediation by host tRNA-derived small noncoding RNAs. BMC Infect Dis 2013; 13:285. [PMID: 23800282 PMCID: PMC3699377 DOI: 10.1186/1471-2334-13-285] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 06/12/2013] [Indexed: 01/19/2023] Open
Abstract
Background Microvascular endothelial barrier dysfunction is the central enigma in spotted fever group (SFG) rickettsioses. Angiogenin (ANG) is one of the earliest identified angiogenic factors, of which some are relevant to the phosphorylation of VE-cadherins that serve as endothelial adherens proteins. Although exogenous ANG is known to translocate into the nucleus of growing endothelial cells (ECs) where it plays a functional role, nuclear ANG is not detected in quiescent ECs. Besides its nuclear role, ANG is thought to play a cytoplasmic role, owing to its RNase activity that cleaves tRNA to produce small RNAs. Recently, such tRNA-derived RNA fragments (tRFs) have been shown to be induced under stress conditions. All these observations raise an intriguing hypothesis about a novel cytoplasmic role of ANG, which is induced upon infection with Rickettsia and generates tRFs that may play roles in SFG rickettsioses. Methods C3H/HeN mice were infected intravenously with a sublethal dose of R. conorii. At days 1, 3, and 5 post infection (p.i.), liver, lung and brain were collected for immunofluorescence (IF) studies of R. conorii and angiogenin (ANG). Human umbilical vein endothelial cells (HUVECs) were infected with R. conorii for 24, 48, and 72 hrs before incubation with 1μg/ml recombinant human ANG (rANG) in normal medium for 2 hrs. HUVEC samples were subjected to IF, exogenous ANG translocation, endothelial permeability, and immunoprecipitation phosphorylation assays. To identify small non-coding RNAs (sncRNAs) upon rickettsial infection, RNAs from pulverized mouse lung tissues and HUVECs were subjected to library preparation and deep sequencing analysis using an Illumina 2000 instrument. Identified sncRNAs were confirmed by Northern hybridization, and their target mRNAs were predicted in silico using BLAST and RNA hybrid programs. Results In the present study, we have demonstrated endothelial up-regulation of ANG, co-localized with SFG rickettsial infection in vivo. We also have provided direct evidence that rickettsial infection sensitizes human ECs to the translocation of exogenous ANG in a compartmentalized pattern at different times post-infection. Typically, exogenous ANG translocates into the nucleus at 24 hrs and to the cytoplasm at 72 hrs post-infection. The ANG cytoplasmic translocation enhances phosphorylation and destabilization of VE-cadherin and attenuates endothelial barrier function. Of note, deep sequencing analysis detected tRFs, mostly derived from the 5'-halves of host tRNAs, that are induced by ANG. Northern hybridization validates the two most abundantly cloned tRFs derived from tRNA-ValGTG and tRNA-GlyGCC, in both mouse tissues and human cells. Bioinformatics analysis predicted that these tRFs may interact with transcripts associated with the endothelial barrier, the host cell inflammatory response, and autophagy. Conclusions Our data provide new insight into the role of compartmentalized ANG during SFG rickettsioses, and highlight its possible mediation through tRFs.
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Affiliation(s)
- Bin Gong
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, USA.
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Abstract
Rocky Mountain spotted fever is typically undifferentiated from many other infections in the first few days of illness. Treatment should not be delayed pending confirmation of infection when Rocky Mountain spotted fever is suspected. Doxycycline is the drug of choice even for infants and children less than 8 years old.
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Astrup E, Lekva T, Davì G, Otterdal K, Santilli F, Oie E, Halvorsen B, Damås JK, Raoult D, Vitale G, Olano JP, Ueland T, Aukrust P. A complex interaction between Rickettsia conorii and Dickkopf-1--potential role in immune evasion mechanisms in endothelial cells. PLoS One 2012; 7:e43638. [PMID: 23028464 PMCID: PMC3445570 DOI: 10.1371/journal.pone.0043638] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 07/24/2012] [Indexed: 01/08/2023] Open
Abstract
The pathophysiological hallmark of spotted fever group rickettsioses comprises vascular inflammation. Based on the emerging importance of the wingless (Wnt) pathways in inflammation and vascular biology, we hypothesized that Dickkopf-1 (DKK-1), as a major modulator of Wnt signaling, could be involved in the pathogenesis in rickettsial infections. Our major findings were: (i) While baseline concentration of DKK-1 in patients with R. conorii infection (n = 32) were not different from levels in controls (n = 24), DKK-1 rose significantly from presentation to first follow-up sample (median 7 days after baseline). (ii) In vitro experiments in human umbilical vein endothelial cells (HUVECs) showed that while heat-inactivated R. conorii enhanced the release of interleukin-6 (IL-6) and IL-8, it down-regulated the release of endothelial-derived DKK-1 in a time- and dose-dependent manner. (iii) Silencing of DKK-1 attenuated the release of IL-6, IL-8 and growth-related oncogene (GRO)α in R. conorii-exposed HUVECs, suggesting inflammatory effects of DKK-1. (iv) Silencing of DKK-1 attenuated the expression of tissue factor and enhanced the expression of thrombomodulin in R. conorii-exposed HUVECs suggesting pro-thrombotic effects of DKK-1. The capacity of R. conorii to down-regulate endothelial-derived DKK-1 and the ability of silencing DKK-1 to attenuate R. conorii-induced inflammation in endothelial cells could potentially reflect a novel mechanism by which R. conorii escapes the immune response at the site of infection.
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Affiliation(s)
- Elisabeth Astrup
- Institute of Clinical Medicine, Akershus University Hospital, Lørenskog, Norway.
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Nickerson A, Marik PE. Life-threatening ANCA-positive vasculitis associated with rickettsial infection. BMJ Case Rep 2012; 2012:bcr.03.2012.5993. [PMID: 22669870 DOI: 10.1136/bcr.03.2012.5993] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We present a 47-year-old Caucasian fire fighter who developed multisystem organ failure in the setting of a positive antineutrophil cytoplasmic autoantibody (myeloperoxidase) as well as confirmed Rocky Mountain spotted fever by skin biopsy PCR. This case provided a diagnostic challenge, a rare association of a Rickettsia infection and autoimmune vasculitis as well as a unique management approach.
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Affiliation(s)
- Ashley Nickerson
- Department of Medicine, Eastern Virginia Medical School, Norfolk, Virginia, USA
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Giulieri S, Jaton K, Cometta A, Trellu LT, Greub G. Development of a duplex real-time PCR for the detection of Rickettsia spp. and typhus group rickettsia in clinical samples. ACTA ACUST UNITED AC 2011; 64:92-7. [PMID: 22098502 DOI: 10.1111/j.1574-695x.2011.00910.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 10/31/2011] [Accepted: 11/11/2011] [Indexed: 11/28/2022]
Abstract
Molecular diagnosis using real-time polymerase chain reaction (PCR) may allow earlier diagnosis of rickettsiosis. We developed a duplex real-time PCR that amplifies (1) DNA of any rickettsial species and (2) DNA of both typhus group rickettsia, that is, Rickettsia prowazekii and Rickettsia typhi. Primers and probes were selected to amplify a segment of the 16S rRNA gene of Rickettsia spp. for the pan-rickettsial PCR and the citrate synthase gene (gltA) for the typhus group rickettsia PCR. Analytical sensitivity was 10 copies of control plasmid DNA per reaction. No cross-amplification was observed when testing human DNA and 22 pathogens or skin commensals. Real-time PCR was applied to 16 clinical samples. Rickettsial DNA was detected in the skin biopsies of three patients. In one patient with severe murine typhus, the typhus group PCR was positive in a skin biopsy from a petechial lesion and seroconversion was later documented. The two other patients with negative typhus group PCR suffered from Mediterranean and African spotted fever, respectively; in both cases, skin biopsy was performed on the eschar. Our duplex real-time PCR showed a good analytical sensitivity and specificity, allowing early diagnosis of rickettsiosis among three patients, and recognition of typhus in one of them.
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Affiliation(s)
- Stefano Giulieri
- Infectious Diseases Service, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
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Duan C, Meng Y, Wang X, Xiong X, Wen B. Exploratory study on pathogenesis of far-eastern spotted fever. Am J Trop Med Hyg 2011; 85:504-9. [PMID: 21896812 DOI: 10.4269/ajtmh.2011.10-0660] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Far-eastern spotted fever is an emerging disease caused by Rickettsia heilongjiangensis, a tick-borne obligate intracellular bacterium. In this study, R. heilongjiangensis was used to infect BALB/c mice by inoculation of retro-orbital venous plexus to imitate a blood infection caused by tick biting. We found that R. heilongjiangensis rapidly entered the circulation for systemic dissemination and the pathogen existed in liver, spleen, lungs, and brain of the mice at least 9 days post-infection (p.i.). Severe pathological lesions were observed in liver, lungs, and brain at Day 6 p.i. In addition, the elevated levels of inflammatory cytokines, including interferon-γ, tumor necrosis factor, and CC chemokine, were detected in the infected organs at Day 3 p.i. Our results reveal that R. heilongjiangensis may cause an infection in BALB/c mice and the pathological lesions in the infected mice are associated with host inflammatory response induced by R. heilongjiangensis.
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Affiliation(s)
- Changsong Duan
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
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Shanker K, Tolan RW. A child with a hive-like rash and bilateral sixth nerve palsies. Clin Pediatr (Phila) 2011; 50:573-4. [PMID: 20724345 DOI: 10.1177/0009922810373652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Kanika Shanker
- The Children's Hospital at Saint Peter's University Hospital, New Brunswick, NJ, USA
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