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Zhong Z, Wang K, Wang J. Tick symbiosis. CURRENT OPINION IN INSECT SCIENCE 2024; 62:101163. [PMID: 38244689 DOI: 10.1016/j.cois.2024.101163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 12/29/2023] [Accepted: 01/12/2024] [Indexed: 01/22/2024]
Abstract
As obligate blood-feeders, ticks serve as vectors for a variety of pathogens that pose threats on both human and livestock health. The microbiota that ticks harbor play important roles in influencing tick nutrition, development, reproduction, and vector. These microbes also affect the capacity of ticks to transmit pathogens (vector competence). Therefore, comprehending the functions of tick microbiota will help in developing novel and effective tick control strategies. Here, we summarize the effects of main tick symbiotic bacteria on tick physiology and vector competency.
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Affiliation(s)
- Zhengwei Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, PR China; Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, PR China
| | - Kun Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, PR China; Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, PR China
| | - Jingwen Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, PR China; Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, PR China.
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2
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Ji H, Wei X, Ma D, Wang X, Liu Q. Predicting the global potential distribution of two major vectors of Rocky Mountain Spotted Fever under conditions of global climate change. PLoS Negl Trop Dis 2024; 18:e0011883. [PMID: 38198451 PMCID: PMC10805312 DOI: 10.1371/journal.pntd.0011883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 01/23/2024] [Accepted: 12/25/2023] [Indexed: 01/12/2024] Open
Abstract
Rocky Mountain spotted fever is a tick-borne disease that is highly dangerous but often overlooked by the public. To prevent the spread of the disease, it is important to understand the distribution patterns of its vectors' suitable areas. This study aims to explore the potential global suitability of areas for the vectors of Rocky Mountain spotted fever, including Dermacentor variabilis and Amblyomma cajennense under both historical and future climate scenarios. The study also seeks to investigate the impact of climatic factors on the distribution patterns of these vectors. Data on species distribution were downloaded from the Global Biodiversity Information Facility, Web of Science and PubMed database. The climatic variables were downloaded from WorldClim Global Climate Database. The Maximum Entropy Model was used to evaluate the contribution of monthly precipitation, monthly maximum temperature, monthly minimum temperature, elevation, and nineteen other climatic variables to vector survival, as well as to predict the suitable area for the vectors. We found that D. variabilis is distributed in North America, while A. cajennense is mainly distributed in South America, but all other continents except Antarctica have a suitable distribution. D. variabilis is more likely to survive in temperate regions, and A. cajennense is more likely to survive in tropical zones. D. variabilis is more sensitive to temperature, whereas A. cajennense is sensitive to both temperature and precipitation, and A. cajennense prefers tropical regions with hot and humid characteristics. The high suitable areas of both vectors were almost expanded in the ssp5-8.5 scenario, but not so much in the ssp1-2.6 scenario. Highly suitable areas with vectors survival should be strengthened with additional testing to prevent related diseases from occurring, and other highly suitable areas should be alert for entry and exit monitoring to prevent invasion and colonization of vectors.
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Affiliation(s)
- Haoqiang Ji
- Department of Vector Control, Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong province, China
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Vector Surveillance and Management, Beijing, China
| | - Xiaohui Wei
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Vector Surveillance and Management, Beijing, China
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu province, China
| | - Delong Ma
- Jinan Shizhong District Center for Disease Control and Prevention, Jinan, Shandong province, China
| | - Xiaoxu Wang
- Department of Vector Control, Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong province, China
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Vector Surveillance and Management, Beijing, China
| | - Qiyong Liu
- Department of Vector Control, Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong province, China
- National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Vector Surveillance and Management, Beijing, China
- School of Public Health, Nanjing Medical University, Nanjing, Jiangsu province, China
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3
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Chaparro-Gutiérrez JJ, Acevedo-Gutiérrez LY, Mendell NL, Robayo-Sánchez LN, Rodríguez-Durán A, Cortés-Vecino JA, Fernández D, Ramírez-Hernández A, Bouyer DH. First isolation of Rickettsia amblyommatis from Amblyomma mixtum in Colombia. Parasit Vectors 2023; 16:332. [PMID: 37730727 PMCID: PMC10510177 DOI: 10.1186/s13071-023-05950-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/27/2023] [Indexed: 09/22/2023] Open
Abstract
BACKGROUND Rickettsiae are obligate intracellular Gram-negative bacteria that are the causative agent of rickettsioses and are spread to vertebrate hosts by arthropods. There are no previous reports of isolation of Rickettsia amblyommatis for Colombia. METHODS A convenience sampling was executed in three departments in Colombia for direct collection of adult ticks on domestic animals or over vegetation. Ticks were screened for the presence of Rickettsia spp. by real-time polymerase chain reaction (qPCR) amplifying the citrate synthase gene (gltA), and the positive sample was processed for isolation and further molecular characterization by conventional PCR. The absolute and relative frequencies were calculated for several tick species variables. All products from conventional PCR were further purified and sequenced by the Sanger technique. Representative sequences of 18 Rickettsia species were downloaded from GenBank. Consensus phylogenetic trees were constructed for the gltA, ompB, ompA, and htrA genes with 1000 replicates, calculating bootstrap values through the maximum likelihood method and the generalized time reversible substitution model in the MEGA 7.0 software program. RESULTS One female Amblyomma mixtum collected on vegetation was amplified by qPCR (gltA), indicating a frequency of 1.6% (1/61) for Rickettsia spp. INFECTION Sequence analysis of a rickettsial isolate from this tick in BLASTn showed 100% identity with gltA (340 base pairs [bp]), 99.87% for ompB (782 bp), 98.99% for htrA (497 bp), and 100% for ompA (488 bp) to R. amblyommatis. Concatenated phylogenetic analysis confirmed these findings indicating that the isolate is grouped with other sequences of Amblyomma cajennense complex from Panama and Brazil within the R. amblyommatis clade. CONCLUSIONS This paper describes the isolation and early molecular identification of a R. amblyommatis strain from A. mixtum in Colombia.
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Affiliation(s)
| | - Leidy Y Acevedo-Gutiérrez
- Department of Agricultural Sciences, Faculty of Veterinary Medicine, Lasallian University Corporation (Unilasallista), GIVET Research Group, Caldas, Antioquia, Colombia
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77550, USA
| | - Nicole L Mendell
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77550, USA
| | - Laura N Robayo-Sánchez
- Research Group Veterinary Parasitology, Laboratorio de Parasitología Veterinaria, Universidad Nacional de Colombia, UNAL, Bogotá, Colombia
| | - Arlex Rodríguez-Durán
- Research Group Veterinary Parasitology, Laboratorio de Parasitología Veterinaria, Universidad Nacional de Colombia, UNAL, Bogotá, Colombia
| | - Jesús A Cortés-Vecino
- Research Group Veterinary Parasitology, Laboratorio de Parasitología Veterinaria, Universidad Nacional de Colombia, UNAL, Bogotá, Colombia
| | - Diana Fernández
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77550, USA
| | - Alejandro Ramírez-Hernández
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77550, USA
- Universidad de La Salle, Bogotá, D.C., Colombia
| | - Donald H Bouyer
- Department of Pathology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77550, USA.
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Pan YS, Cui XM, Du LF, Xia LY, Du CH, Bell-Sakyi L, Zhang MZ, Zhu DY, Dong Y, Wei W, Zhao L, Sun Y, Lv QY, Ye RZ, He ZH, Wang Q, Li LJ, Yao MG, Xiong T, Jiang JF, Cao WC, Jia N. Coinfection of Two Rickettsia Species in a Single Tick Species Provides New Insight into Rickettsia- Rickettsia and Rickettsia-Vector Interactions. Microbiol Spectr 2022; 10:e0232322. [PMID: 36173317 PMCID: PMC9603609 DOI: 10.1128/spectrum.02323-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 09/15/2022] [Indexed: 01/04/2023] Open
Abstract
Rickettsiae are obligate intracellular bacteria that can cause life-threatening illnesses. There is an ongoing debate as to whether established infections by one Rickettsia species preclude the maintenance of the second species in ticks. Here, we identified two Rickettsia species in inoculum from Haemaphysalis montgomeryi ticks and subsequently obtained pure isolates of each species by plaque selection. The two isolates were classified as a transitional group and spotted fever group rickettsiae and named Rickettsia hoogstraalii str CS and Rickettsia rhipicephalii str EH, respectively. The coinfection of these two Rickettsia species was detected in 25.6% of individual field-collected H. montgomeryi. In cell culture infection models, R. hoogstraalii str CS overwhelmed R. rhipicephalii str EH with more obvious cytopathic effects, faster plaque formation, and increased cellular growth when cocultured, and R. hoogstraalii str CS seemed to polymerize actin tails differently from R. rhipicephalii str EH in vitro. This work provides a model to investigate the mechanisms of both Rickettsia-Rickettsia and Rickettsia-vector interactions. IMPORTANCE The rickettsiae are a group of obligate intracellular Gram-negative bacteria that include human pathogens causing an array of clinical symptoms and even death. There is an important question in the field, that is whether one infection can block the superinfection of other rickettsiae. This work demonstrated the coinfection of two Rickettsia species in individual ticks and further highlighted that testing the rickettsial competitive exclusion hypothesis will undoubtedly be a promising area as methods for bioengineering and pathogen biocontrol become amenable for rickettsiae.
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Affiliation(s)
- Yu-Sheng Pan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Xiao-Ming Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Li-Feng Du
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Luo-Yuan Xia
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Chun-Hong Du
- Yunnan Institute for Endemic Diseases Control and Prevention, Dali, Yunnan, People’s Republic of China
| | - Lesley Bell-Sakyi
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Ming-Zhu Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Dai-Yun Zhu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Yi Dong
- Yunnan Institute for Endemic Diseases Control and Prevention, Dali, Yunnan, People’s Republic of China
| | - Wei Wei
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Lin Zhao
- Institute of EcoHealth, School of Public Health, Shandong University, Jinan, Shandong, People’s Republic of China
| | - Yi Sun
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Qing-Yu Lv
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Run-Ze Ye
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Zhi-Hai He
- Yunnan Institute for Endemic Diseases Control and Prevention, Dali, Yunnan, People’s Republic of China
| | - Qian Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Liang-Jing Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Ming-Guo Yao
- Yunnan Institute for Endemic Diseases Control and Prevention, Dali, Yunnan, People’s Republic of China
| | - Tao Xiong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Jia-Fu Jiang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Wu-Chun Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Na Jia
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
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5
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Paddock CD, Slater K, Swei A, Zambrano ML, Kleinjan JE, Padgett KA, Saunders MEM, Andrews ES, Trent E, Zhong J, Sambado S, Goldsmith CS, Pascoe EL, Foley J, Lane RS, Karpathy SE. Detection and Isolation of Rickettsia tillamookensis (Rickettsiales: Rickettsiaceae) From Ixodes pacificus (Acari: Ixodidae) From Multiple Regions of California. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:1404-1412. [PMID: 35468215 DOI: 10.1093/jme/tjac038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Indexed: 06/14/2023]
Abstract
The western black-legged tick (Ixodes pacificus) is the most frequently identified human-biting tick species in the western United States and the principal vector of at least three recognized bacterial pathogens of humans. A potentially pathogenic Rickettsia species, first described in 1978 and recently characterized as a novel transitional group agent designated as Rickettsia tillamookensis, also exists among populations of I. pacificus, although the distribution and frequency of this agent are poorly known. We evaluated DNA extracts from 348 host-seeking I. pacificus nymphs collected from 9 locations in five California counties, and from 916 I. pacificus adults collected from 24 locations in 13 counties, by using a real-time PCR designed specifically to detect DNA of R. tillamookensis. DNA of R. tillamookensis was detected in 10 (2.9%) nymphs (95% CI: 1.6-5.2%) and 17 (1.9%) adults (95% CI: 1.2-3.0%) from 11 counties of northern California. Although site-specific infection rates varied greatly, frequencies of infection remained consistently low when aggregated by stage, sex, habitat type, or geographical region. Four novel isolates of R. tillamookensis were cultivated in Vero E6 cells from individual adult ticks collected from Alameda, Nevada, and Yolo counties. Four historical isolates, serotyped previously as 'Tillamook-like' strains over 40 yr ago, were revived from long-term storage in liquid nitrogen and confirmed subsequently by molecular methods as isolates of R. tillamookensis. The potential public health impact of R. tillamookensis requires further investigation.
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Affiliation(s)
- Christopher D Paddock
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Kimetha Slater
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - Maria L Zambrano
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Joyce E Kleinjan
- Alameda County Vector Control Services District, Alameda, CA, USA
| | - Kerry A Padgett
- Vector-Borne Disease Section, California Department of Public Health, Richmond, CA, USA
| | - Megan E M Saunders
- Vector-Borne Disease Section, California Department of Public Health, Richmond, CA, USA
| | - Elizabeth S Andrews
- Vector-Borne Disease Section, California Department of Public Health, Richmond, CA, USA
| | - Erin Trent
- Department of Biological Sciences, Humboldt State University, Arcata, CA, USA
| | - Jianmin Zhong
- Department of Biological Sciences, Humboldt State University, Arcata, CA, USA
| | - Samantha Sambado
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Cynthia S Goldsmith
- Infectious Diseases Pathology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Emily L Pascoe
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Janet Foley
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Robert S Lane
- Department of Environmental Science, Policy and Management, University of California, Berkeley CA, USA
| | - Sandor E Karpathy
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
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6
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Duncan KT, Grant A, Johnson B, Sundstrom KD, Saleh MN, Little SE. Identification of Rickettsia spp. and Babesia conradae in Dermacentor spp. Collected from Dogs and Cats Across the United States. Vector Borne Zoonotic Dis 2021; 21:911-920. [PMID: 34958266 PMCID: PMC8742288 DOI: 10.1089/vbz.2021.0047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In the United States, Dermacentor variabilis and Dermacentor andersoni are considered key vectors for Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. Through regional surveillance, a wide diversity of Rickettsia spp. have been documented in D. variabilis, and Dermacentor spp. has been suggested as potential vectors for various other pathogens, including Babesia spp. and Ehrlichia canis. To better define the prevalence and diversity of pathogens in Dermacentor spp. across the United States, 848 ticks collected from dogs and cats in 44/50 states in 2018–2019 were tested by PCR for Rickettsia spp.-specific 17 kDa and ompA gene fragments; a subset of Dermacentor spp. was also tested with PCR, targeting fragments of the 18S and large subunit region rRNA genes of Babesia spp. and 16S rRNA genes of E. canis. Rickettsia spp. was identified in 12.5% (106/848) of ticks. Species detected include Rickettsia montanensis (n = 64 ticks), Rickettsia bellii (n = 15 ticks), Rickettsia rhipicephali (n = 13 ticks), Rickettsia peacockii (n = 8 ticks), Rickettsia amblyommatis (n = 3 ticks), Rickettsia cooleyi (n = 1 tick), and unclassified Rickettsia spp. (n = 2 ticks). Ticks with R. montanensis and R. bellii were submitted from every U.S. region; R. rhipicephali was predominantly detected in ticks from the southern half of the United States, and all R. peacockii-positive ticks were D. andersoni that originated from the Rocky Mountain states. Ehrlichia canis was not detected in any Dermacentor spp., and Babesia conradae was detected in two Dermacentor albipictus. Because most ticks had fed on dogs or cats before submission, these findings do not implicate a given Dermacentor sp. as a primary vector of these agents, but in regard to Rickettsia spp., the data do support other published work showing D. variabilis harbors a diversity of Rickettsia species with unknown implications for animal and human health.
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Affiliation(s)
- Kathryn T Duncan
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Amber Grant
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Britny Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA.,Rickettsial Zoonoses Branch, Division of Vector-Borne Disease, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Kellee D Sundstrom
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Meriam N Saleh
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA.,Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Susan E Little
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA
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7
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Kristof MN, Allen PE, Yutzy LD, Thibodaux B, Paddock CD, Martinez JJ. Significant Growth by Rickettsia Species within Human Macrophage-Like Cells Is a Phenotype Correlated with the Ability to Cause Disease in Mammals. Pathogens 2021; 10:pathogens10020228. [PMID: 33669499 PMCID: PMC7934685 DOI: 10.3390/pathogens10020228] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 11/16/2022] Open
Abstract
Rickettsia are significant sources of tick-borne diseases in humans worldwide. In North America, two species in the spotted fever group of Rickettsia have been conclusively associated with disease of humans: Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, and Rickettsia parkeri, the cause of R. parkeri rickettsiosis. Previous work in our lab demonstrated non-endothelial parasitism by another pathogenic SFG Rickettsia species, Rickettsia conorii, within THP-1-derived macrophages, and we have hypothesized that this growth characteristic may be an underappreciated aspect of rickettsial pathogenesis in mammalian hosts. In this work, we demonstrated that multiple other recognized human pathogenic species of Rickettsia, including R. rickettsii, R. parkeri, Rickettsia africae, and Rickettsiaakari can grow within target endothelial cells as well as within PMA-differentiated THP-1 cells. In contrast, Rickettsia bellii, a Rickettsia species not associated with disease of humans, and R. rickettsii strain Iowa, an avirulent derivative of pathogenic R. rickettsii, could invade both cell types but proliferate only within endothelial cells. Further analysis revealed that similar to previous studies on R. conorii, other recognized pathogenic Rickettsia species could grow within the cytosol of THP-1-derived macrophages and avoided localization with two different markers of lysosomal compartments; LAMP-2 and cathepsin D. R. bellii, on the other hand, demonstrated significant co-localization with lysosomal compartments. Collectively, these findings suggest that the ability of pathogenic rickettsial species to establish a niche within macrophage-like cells could be an important factor in their ability to cause disease in mammals. These findings also suggest that analysis of growth within mammalian phagocytic cells may be useful to predict the pathogenic potential of newly isolated and identified Rickettsia species.
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Affiliation(s)
- M. Nathan Kristof
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA; (M.N.K.); (P.E.A.); (L.D.Y.); (B.T.)
| | - Paige E. Allen
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA; (M.N.K.); (P.E.A.); (L.D.Y.); (B.T.)
| | - Lane D. Yutzy
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA; (M.N.K.); (P.E.A.); (L.D.Y.); (B.T.)
| | - Brandon Thibodaux
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA; (M.N.K.); (P.E.A.); (L.D.Y.); (B.T.)
| | - Christopher D. Paddock
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Atlanta, GA 30329, USA;
| | - Juan J. Martinez
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, LA 70803, USA; (M.N.K.); (P.E.A.); (L.D.Y.); (B.T.)
- Correspondence: ; Tel.: +1-225-578-9297
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8
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Occi J, Egizi AM, Goncalves A, Fonseca DM. New Jersey-Wide Survey of Spotted Fever Group Rickettsia (Proteobacteria: Rickettsiaceae) in Dermacentor variabilis and Amblyomma americanum (Acari: Ixodida: Ixodidae). Am J Trop Med Hyg 2020; 103:1009-1016. [PMID: 32588804 DOI: 10.4269/ajtmh.20-0145] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
For the last decade, the New Jersey (NJ) Department of Health has reported between 42 and 144 new cases each year of "spotted fever group rickettsiosis" (SFGR), a statistic that reflects uncertainty regarding which rickettsial agents (Proteobacteria: Rickettsiaceae: Rickettsia) are infecting NJ residents. To identify the Rickettsia circulating in NJ ticks, we used a combination of conventional and real time PCR approaches to screen 560 Dermacentor variabilis Say and 245 Amblyomma americanum L. obtained from a 1-day state-wide surveillance in May 2018 and an additional 394 D. variabilis collected across NJ in 2013-2018. We found zero D. variabilis infected with Rickettsia rickettsii, the agent of Rocky Mountain spotted fever and, on average, 1.3% infected with presumed nonpathogenic Rickettsia montanensis. We also found zero A. americanum infected with R. rickettsii, and 20% infected with Rickettsia amblyommatis, a prevalence somewhat lower than in more southern states. Overall, we conclude that it is unlikely that R. rickettsii vectored by D. variabilis is a primary cause of SFGR cases in NJ and discuss our findings in the context of known facts and current limitations. We conclude that understanding the causes of SFGR east of the Mississippi will require collaboration among medical doctors, public health authorities, and medical entomologists to follow up presumptive human cases of SFGR with detailed histories of exposure, species-specific molecular assays, and active surveillance of putative vectors and the pathogens they may carry.
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Affiliation(s)
- James Occi
- Department of Entomology, Center for Vector Biology, Rutgers University, New Brunswick, New Jersey
| | - Andrea M Egizi
- Monmouth County Mosquito Control Division, Tick-borne Diseases Laboratory, Tinton Falls, New Jersey.,Department of Entomology, Center for Vector Biology, Rutgers University, New Brunswick, New Jersey
| | - Ashley Goncalves
- Department of Entomology, Center for Vector Biology, Rutgers University, New Brunswick, New Jersey
| | - Dina M Fonseca
- Department of Entomology, Center for Vector Biology, Rutgers University, New Brunswick, New Jersey
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Two for the price of one: Co-infection with Rickettsia bellii and spotted fever group Rickettsia in Amblyomma (Acari: Ixodidae) ticks recovered from wild birds in Brazil. Ticks Tick Borne Dis 2019; 10:101266. [PMID: 31402227 DOI: 10.1016/j.ttbdis.2019.101266] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/17/2019] [Accepted: 07/28/2019] [Indexed: 11/21/2022]
Abstract
The bacterium Rickettsia bellii has been detected in 25 species of ticks in the American continents, but its pathogenic potential is considered as undetermined. A possible role for this species in the phenomenon of transovarial exclusion of pathogenic members of the spotted fever group (SFG) of Rickettsia has been suggested and co-infections with pathogenic species have been reported infrequently in both North and South America. Traditional methods for the molecular detection of rickettsial agents in ticks focus largely on the identification of sequences found in SFG Rickettsia, an approach that may overlook the presence of co-infections with R. bellii. Two novel, species-specific polymerase chain reaction (PCR) assays, targeting the genes encoding the surface cell antigen (Sca), autotransporter proteins sca9 and sca14, were developed and validated for the detection of R. bellii using 150 Amblyomma ticks collected from wild birds in Brazil. Co-infection of R. bellii infected ticks was evaluated using a novel PCR assay targeting the ompA sequence characteristic of SFG Rickettsia. Preliminary species-level identification was achieved by restriction fragment length polymorphism (RFLP) analysis and subsequently confirmed by sequencing of amplicons. Nine out of seventy-three Amblyomma longirostre and one of two Amblyomma calcaratum ticks were shown to be co-infected with R. bellii and Rickettsia amblyommatis, while two out of sixty-seven Amblyomma sp. haplotype Nazaré ticks were recorded as co-infected with R. bellii and the Rickettsia parkeri-like bacterium, strain ApPR. Interestingly, our data represent the first records of R. bellii in association with A. calcaratum and Amblyomma sp. haplotype Nazaré. The novel PCR-RFLP systems reported herein, provide an alternative, rapid and cost-efficient (relative to strategies based on sequencing or real-time PCR), approach to evaluate rickettsial co-infection of ticks, a potentially significant phenomenon that has most likely been underestimated to date.
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10
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Kakumanu ML, Ponnusamy L, Sutton H, Meshnick SR, Nicholson WL, Apperson CS. Prevalence of Rickettsia Species (Rickettsiales: Rickettsiaceae) in Dermacentor variabilis Ticks (Acari: Ixodidae) in North Carolina. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:1284-1291. [PMID: 29771344 DOI: 10.1093/jme/tjy074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Indexed: 06/08/2023]
Abstract
The American dog tick, Dermacentor variabilis (Say), is a vector of spotted fever group (SFG) rickettsiae, including Rickettsia rickettsii the causative organism of Rocky Mountain spotted fever (RMSF). In North Carolina, SFG rickettsioses (including RMSF) are a leading cause of tick-borne illness. Knowledge of the infection rate and geographic distribution of D. variabilis ticks infected with Rickettsia spp. provides information on the spatial distribution of public health risk. Accordingly, we extracted genomic DNA from adult D. variabilis collected from field habitats in 32 North Carolina counties from 2009 to 2013. A nested PCR assay of the 23S-5S intergenic spacer (IGS) region of Rickettsia coupled with reverse line blot hybridization (RLBH) with species-specific probes was used to detect and identify rickettsiae to species. Approximately half of the 532 tick DNA samples exhibited a band of the expected size on agarose gels, indicating infection with Rickettsia spp. RLBH analyses showed R. amblyommatis (formerly 'Candidatus R. amblyommii'), R. parkeri, and R. montanensis were predominant, while other Rickettsia species detected included R. conorii-like, R. massiliae, R. rhipicephali, R. canadensis, R. bellii, and some unknown Rickettsia spp. Some ticks were infected with more than one Rickettsia species. Notably, several Rickettsia-positive ticks harbored R. rickettsii. DNA sequencing was performed on a portion of the 23S-5S IGS amplicons and the results were concordant with RLB assay results. We conclude that Rickettsia spp. are common in D. variabilis in North Carolina. Geographic patterns in the occurrence of Rickettsia-infected D. variabilis ticks across the counties sampled are discussed.
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Affiliation(s)
- Madhavi L Kakumanu
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Loganathan Ponnusamy
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC
| | - Haley Sutton
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC
| | - William L Nicholson
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA
| | - Charles S Apperson
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC
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11
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Trout Fryxell RT, Hendricks BM, Pompo K, Mays SE, Paulsen DJ, Operario DJ, Houston AE. Investigating the Adult Ixodid Tick Populations and Their Associated Anaplasma, Ehrlichia, and Rickettsia Bacteria at a Rocky Mountain Spotted Fever Hotspot in Western Tennessee. Vector Borne Zoonotic Dis 2017; 17:527-538. [PMID: 28598270 DOI: 10.1089/vbz.2016.2091] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Ehrlichiosis and rickettsiosis are two common bacterial tick-borne diseases in the southeastern United States. Ehrlichiosis is caused by ehrlichiae transmitted by Amblyomma americanum and rickettsiosis is caused by rickettsiae transmitted by Amblyomma maculatum and Dermacentor variabilis. These ticks are common and have overlapping distributions in the region. The objective of this study was to identify Anaplasma, Ehrlichia, and Rickettsia species associated with questing ticks in a Rocky Mountain spotted fever (RMSF) hotspot, and identify habitats, time periods, and collection methods for collecting questing-infected ticks. Using vegetation drags and CO2-baited traps, ticks were collected six times (May-September 2012) from 100 sites (upland deciduous, bottomland deciduous, grassland, and coniferous habitats) in western Tennessee. Adult collections were screened for Anaplasma and Ehrlichia (simultaneous polymerase chain reaction [PCR]) and Rickettsia using genus-specific PCRs, and resulting positive amplicons were sequenced. Anaplasma and Ehrlichia were only identified within A. americanum (Ehrlichia ewingii, Ehrlichia chaffeensis, Panola Mountain Ehrlichia, and Anaplasma odocoilei sp. nov.); more Ehrlichia-infected A. americanum were collected at the end of June regardless of habitat and collection method. Rickettsia was identified in three tick species; "Candidatus Rickettsia amblyommii" from A. americanum, R. parkeri and R. andeanae from A. maculatum, and R. montanensis ( = montana) from D. variabilis. Overall, significantly more Rickettsia-infected ticks were identified as A. americanum and A. maculatum compared to D. variabilis; more infected-ticks were collected from sites May-July and with dragging. In this study, we report in the Tennessee RMSF hotspot the following: (1) Anaplasma and Ehrlichia are only found in A. americanum, (2) each tick species has its own Rickettsia species, (3) a majority of questing-infected ticks are collected May-July, (4) A. americanum and A. maculatum harbor pathogenic bacteria in western Tennessee, and (5) R. rickettsii remains unidentified.
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Affiliation(s)
- Rebecca T Trout Fryxell
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Brain M Hendricks
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Kimberly Pompo
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Sarah E Mays
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Dave J Paulsen
- 1 Department of Entomology and Plant Pathology, University of Tennessee , Knoxville, Tennessee
| | - Darwin J Operario
- 2 Division of Infectious Diseases and International Health, University of Virginia Health System , Charlottesville, Virginia
| | - Allan E Houston
- 3 Department of Forestry, Wildlife and Fisheries, University of Tennessee , Knoxville, Tennessee
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12
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Levin ML, Zemtsova GE, Killmaster LF, Snellgrove A, Schumacher LBM. Vector competence of Amblyomma americanum (Acari: Ixodidae) for Rickettsia rickettsii. Ticks Tick Borne Dis 2017; 8:615-622. [PMID: 28433728 DOI: 10.1016/j.ttbdis.2017.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 03/03/2017] [Accepted: 04/10/2017] [Indexed: 11/30/2022]
Abstract
Rickettsia rickettsii - the etiologic agent of Rocky Mountain spotted fever (RMSF) - is widely spread across the Americas. In the US, Dermacentor spp. ticks are identified as primary vectors of R. rickettsii and Rhipicephalus sanguineus s.l. has been implicated in transmission of this pathogen in several locations in the Southwest. Conversely, ticks of the genus Amblyomma are recognized vectors of RMSF in Central and South America, but not in the US. A. americanum is one of the most aggressive human-biting ticks in the US, whose geographical range overlaps with that of reported RMSF cases. Despite sporadic findings of R. rickettsii DNA in field-collected A. americanum and circumstantial association of this species with human RMSF cases, its vector competence for R. rickettsii has not been appropriately studied. Therefore, we assessed the ability of A. americanum to acquire and transmit two geographically distant isolates of R. rickettsii. The Di-6 isolate of R. rickettsii used in this study originated in Virginia and the AZ-3 isolate originated in Arizona. Under laboratory conditions, A. americanum demonstrated vector competence for both isolates, although the efficiency of acquisition and transovarial transmission was higher for Di-6 than for AZ-3 isolate. Uninfected larvae acquired the pathogen from systemically infected guinea pigs, as well as while feeding side by side with Rickettsia-infected ticks on non-rickettsiemic hosts. Once acquired, R. rickettsii was successfully maintained through the tick molting process and transmitted to susceptible animals during subsequent feedings. Guinea pigs and dogs infested with infected A. americanum developed fever, scrotal edema and dermatitis or macular rash. R. rickettsii DNA was identified in animal blood, skin, and internal organs. The prevalence of infection within tick cohorts gradually increased due to side-by-side feeding of infected and uninfected individuals from 33 to 49% in freshly molted nymphs to 71-98% in engorged females. Moreover, R. rickettsii was transmitted transovarially by approximately 28% and 14% of females infected with Di-6 and AZ-3 isolates, respectively. Hence, A. americanum is capable of acquiring, maintaining and transmitting R. rickettsii isolates originating from two different geographical regions of the US, at least under laboratory conditions. Its role in ecology and epidemiology of RMSF in the US deserves further investigation.
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Affiliation(s)
- Michael L Levin
- Rickettsial Zoonoses Branch, Centers for Disease Control, Prevention, Atlanta, GA, United States.
| | - Galina E Zemtsova
- Rickettsial Zoonoses Branch, Centers for Disease Control, Prevention, Atlanta, GA, United States
| | - Lindsay F Killmaster
- Rickettsial Zoonoses Branch, Centers for Disease Control, Prevention, Atlanta, GA, United States
| | - Alyssa Snellgrove
- Rickettsial Zoonoses Branch, Centers for Disease Control, Prevention, Atlanta, GA, United States
| | - Lauren B M Schumacher
- Rickettsial Zoonoses Branch, Centers for Disease Control, Prevention, Atlanta, GA, United States
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13
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Curto P, Simões I, Riley SP, Martinez JJ. Differences in Intracellular Fate of Two Spotted Fever Group Rickettsia in Macrophage-Like Cells. Front Cell Infect Microbiol 2016; 6:80. [PMID: 27525249 PMCID: PMC4965480 DOI: 10.3389/fcimb.2016.00080] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/18/2016] [Indexed: 12/21/2022] Open
Abstract
Spotted fever group (SFG) rickettsiae are recognized as important agents of human tick-borne diseases worldwide, such as Mediterranean spotted fever (Rickettsia conorii) and Rocky Mountain spotted fever (Rickettsia rickettsii). Recent studies in several animal models have provided evidence of non-endothelial parasitism by pathogenic SFG Rickettsia species, suggesting that the interaction of rickettsiae with cells other than the endothelium may play an important role in pathogenesis of rickettsial diseases. These studies raise the hypothesis that the role of macrophages in rickettsial pathogenesis may have been underappreciated. Herein, we evaluated the ability of two SFG rickettsial species, R. conorii (a recognized human pathogen) and Rickettsia montanensis (a non-virulent member of SFG) to proliferate in THP-1 macrophage-like cells, or within non-phagocytic cell lines. Our results demonstrate that R. conorii was able to survive and proliferate in both phagocytic and epithelial cells in vitro. In contrast, R. montanensis was able to grow in non-phagocytic cells, but was drastically compromised in the ability to proliferate within both undifferentiated and PMA-differentiated THP-1 cells. Interestingly, association assays revealed that R. montanensis was defective in binding to THP-1-derived macrophages; however, the invasion of the bacteria that are able to adhere did not appear to be affected. We have also demonstrated that R. montanensis which entered into THP-1-derived macrophages were rapidly destroyed and partially co-localized with LAMP-2 and cathepsin D, two markers of lysosomal compartments. In contrast, R. conorii was present as intact bacteria and free in the cytoplasm in both cell types. These findings suggest that a phenotypic difference between a non-pathogenic and a pathogenic SFG member lies in their respective ability to proliferate in macrophage-like cells, and may provide an explanation as to why certain SFG rickettsial species are not associated with disease in mammals.
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Affiliation(s)
- Pedro Curto
- PhD Programme in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, University of CoimbraCoimbra, Portugal
- Institute for Interdisciplinary Research, University of CoimbraCoimbra, Portugal
- Center for Neuroscience and Cell BiologyCoimbra, Portugal
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary MedicineBaton Rouge, LA, USA
| | - Isaura Simões
- Center for Neuroscience and Cell BiologyCoimbra, Portugal
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary MedicineBaton Rouge, LA, USA
- Biocant, Biotechnology Innovation CenterCantanhede, Portugal
| | - Sean P. Riley
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary MedicineBaton Rouge, LA, USA
| | - Juan J. Martinez
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary MedicineBaton Rouge, LA, USA
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14
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Wood H, Dillon L, Patel SN, Ralevski F. Prevalence of Rickettsia species in Dermacentor variabilis ticks from Ontario, Canada. Ticks Tick Borne Dis 2016; 7:1044-1046. [PMID: 27318438 DOI: 10.1016/j.ttbdis.2016.06.001] [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: 04/27/2016] [Revised: 06/02/2016] [Accepted: 06/03/2016] [Indexed: 11/25/2022]
Abstract
Relatively little is known about the prevalence of rickettsial species in Dermacentor ticks in eastern Canada. In this study, Dermacentor ticks from the province of Ontario, Canada, were tested for the presence of spotted fever group rickettsial (SFGR) species, Coxiella burnetii and Francisella tularensis. Rickettsia rickettsii was not detected in any ticks tested, but R. montanensis was detected at a prevalence of 2.2% in D. variabilis (17/778). Two other SFGR species, R. parkeri and Candidatus R. andeanae, were detected individually in 2 Amblyomma maculatum ticks. Rickettsia peacockii, a non-pathogenic endosymbiont, was detected in two D. andersonii ticks. Given the highly abundant nature of D. variabilis, surveillance for human pathogens in this species of tick has important public health implications, but the lack of detection of known human pathogens indicates a low risk of infection via this tick species in Ontario. However, the detection of R. parkeri in an adventive A. maculatum tick indicates that health care providers should be aware of the possibility of spotted fever rickettsioses in individuals with a history of travel outside of Ontario and symptoms compatible with a spotted fever rickettsiosis. Coxiella burnetii and Francisella tularensis, human pathogens also potentially transmitted by D. variabilis, were not detected in a subset of the ticks.
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Affiliation(s)
- Heidi Wood
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
| | - Liz Dillon
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
| | - Samir N Patel
- Public Health Ontario Laboratory, Public Health Ontario, Toronto, Ontario, Canada.
| | - Filip Ralevski
- Public Health Ontario Laboratory, Public Health Ontario, Toronto, Ontario, Canada.
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15
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Kakumanu ML, Ponnusamy L, Sutton HT, Meshnick SR, Nicholson WL, Apperson CS. Development and Validation of an Improved PCR Method Using the 23S-5S Intergenic Spacer for Detection of Rickettsiae in Dermacentor variabilis Ticks and Tissue Samples from Humans and Laboratory Animals. J Clin Microbiol 2016; 54:972-9. [PMID: 26818674 PMCID: PMC4809929 DOI: 10.1128/jcm.02605-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 01/16/2016] [Indexed: 01/28/2023] Open
Abstract
A novel nested PCR assay was developed to detectRickettsiaspp. in ticks and tissue samples from humans and laboratory animals. Primers were designed for the nested run to amplify a variable region of the 23S-5S intergenic spacer (IGS) ofRickettsiaspp. The newly designed primers were evaluated using genomic DNA from 11Rickettsiaspecies belonging to the spotted fever, typhus, and ancestral groups and, in parallel, compared to otherRickettsia-specific PCR targets (ompA,gltA, and the 17-kDa protein gene). The new 23S-5S IGS nested PCR assay amplified all 11Rickettsiaspp., but the assays employing other PCR targets did not. The novel nested assay was sensitive enough to detect one copy of a cloned 23S-5S IGS fragment from "CandidatusRickettsia amblyommii." Subsequently, the detection efficiency of the 23S-5S IGS nested assay was compared to those of the other three assays using genomic DNA extracted from 40 adultDermacentor variabilisticks. The nested 23S-5S IGS assay detectedRickettsiaDNA in 45% of the ticks, while the amplification rates of the other three assays ranged between 5 and 20%. The novel PCR assay was validated using clinical samples from humans and laboratory animals that were known to be infected with pathogenic species ofRickettsia The nested 23S-5S IGS PCR assay was coupled with reverse line blot hybridization with species-specific probes for high-throughput detection and simultaneous identification of the species ofRickettsiain the ticks. "CandidatusRickettsia amblyommii,"R. montanensis,R. felis, andR. belliiwere frequently identified species, along with some potentially novelRickettsiastrains that were closely related toR. belliiandR. conorii.
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Affiliation(s)
- Madhavi L Kakumanu
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, USA
| | - Loganathan Ponnusamy
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, USA
| | - Haley T Sutton
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, USA
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - William L Nicholson
- Rickettsial Zoonoses Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Charles S Apperson
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, USA Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina, USA
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16
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Molecular detection of bacteria in the families Rickettsiaceae and Anaplasmataceae in northern crested caracaras (Caracara cheriway). Ticks Tick Borne Dis 2016; 7:470-4. [PMID: 26837860 DOI: 10.1016/j.ttbdis.2016.01.015] [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: 09/23/2015] [Revised: 01/05/2016] [Accepted: 01/23/2016] [Indexed: 11/22/2022]
Abstract
Bacterial pathogens of the families Anaplasmataceae and Rickettsiaceae are often spread to humans or other animals from bites from infected arthropod hosts. Recently, an increasing number of studies have implicated migratory birds in the circulation of these pathogens through the spread of arthropod vectors. However, few studies have examined the potential for resident bird populations to serve as reservoirs for these zoonoses. In this study, we used nested PCRs of the GroESL and 17 kDa genes to screen for Anaplasmataceae and Rickettsiaceae, respectively, in a resident population of the northern crested caracara (Caracara cheriway) from Florida (n=55). Additionally, a small number (n=6) of captive individuals from Texas were included. We identified one individual (1.64%) positive for Rickettsia felis and one (1.64%) positive for Ehrlichia chaffeensis; both these individuals were from Florida. Presence of these pathogens demonstrates that these birds are potential hosts; however, the low prevalence of infections suggests that these populations likely do not function as an ecological reservoir.
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17
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The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum). PLoS One 2016; 11:e0146651. [PMID: 26751816 PMCID: PMC4709196 DOI: 10.1371/journal.pone.0146651] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022] Open
Abstract
The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson’s Diversity indices ranging from 1.28–89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.
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18
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Trout Fryxell RT, Steelman CD, Szalanski AL, Billingsley PM, Williamson PC. Molecular Detection of Rickettsia Species Within Ticks (Acari: Ixodidae) Collected from Arkansas United States. JOURNAL OF MEDICAL ENTOMOLOGY 2015; 52:500-508. [PMID: 26334827 DOI: 10.1093/jme/tjv027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 02/24/2015] [Indexed: 06/05/2023]
Abstract
Rocky Mountain spotted fever (RMSF), caused by the etiological agent Rickettsia rickettsii, is the most severe and frequently reported rickettsial illness in the United States, and is commonly diagnosed throughout the southeast. With the discoveries of Rickettsia parkeri and other spotted fever group rickettsiae (SFGR) in ticks, it remains inconclusive if the cases reported as RMSF are truly caused by R. rickettsii or other SFGR. Arkansas reports one of the highest incidence rates of RMSF in the country; consequently, to identify the rickettsiae in Arkansas, 1,731 ticks, 250 white-tailed deer, and 189 canines were screened by polymerase chain reaction (PCR) for the rickettsial genes gltA, rompB, and ompA. None of the white-tailed deer were positive, while two of the canines (1.1%) and 502 (29.0%) of the ticks were PCR positive. Five different tick species were PCR positive: 244 (37%) Amblyomma americanum L., 130 (38%) Ixodes scapularis Say, 65 (39%) Amblyomma maculatum (Koch), 30 (9%) Rhipicephalus sanguineus Latreille, 7 (4%) Dermacentor variabilis Say, and 26 (44%) unidentified Amblyomma ticks. None of the sequenced products were homologous to R. rickettsii. The most common Rickettsia via rompB amplification was Rickettsia montanensis and nonpathogenic Candidatus Rickettsia amblyommii, whereas with ompA amplification the most common Rickettsia was Ca. R. amblyommii. Many tick specimens collected in northwest Arkansas were PCR positive and these were commonly A. americanum harboring Ca. R. amblyommii, a currently nonpathogenic Rickettsia. Data reported here indicate that pathogenic R. rickettsii was absent from these ticks and suggest by extension that other SFGR are likely the causative agents for Arkansas diagnosed RMSF cases.
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Affiliation(s)
- R T Trout Fryxell
- Department of Entomology and Plant Pathology, University of Tennessee, 370 Plant Biotechnology Bldg., 2505 E J Chapman Dr., Knoxville, TN 37996-4560.
| | - C D Steelman
- Department of Entomology, University of Arkansas, Fayetteville Arkansas
| | - A L Szalanski
- Department of Entomology, University of Arkansas, Fayetteville Arkansas
| | - P M Billingsley
- Department of Forensic and Investigative Genetics, University of North Texas Health Science Center, Ft. Worth, Texas
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19
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Eremeeva ME, Dasch GA. Challenges posed by tick-borne rickettsiae: eco-epidemiology and public health implications. Front Public Health 2015; 3:55. [PMID: 25954738 PMCID: PMC4404743 DOI: 10.3389/fpubh.2015.00055] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/18/2015] [Indexed: 11/16/2022] Open
Abstract
Rickettsiae are obligately intracellular bacteria that are transmitted to vertebrates by a variety of arthropod vectors, primarily by fleas and ticks. Once transmitted or experimentally inoculated into susceptible mammals, some rickettsiae may cause febrile illness of different morbidity and mortality, and which can manifest with different types of exhanthems in humans. However, most rickettsiae circulate in diverse sylvatic or peridomestic reservoirs without having obvious impacts on their vertebrate hosts or affecting humans. We have analyzed the key features of tick-borne maintenance of rickettsiae, which may provide a deeper basis for understanding those complex invertebrate interactions and strategies that have permitted survival and circulation of divergent rickettsiae in nature. Rickettsiae are found in association with a wide range of hard and soft ticks, which feed on very different species of large and small animals. Maintenance of rickettsiae in these vector systems is driven by both vertical and horizontal transmission strategies, but some species of Rickettsia are also known to cause detrimental effects on their arthropod vectors. Contrary to common belief, the role of vertebrate animal hosts in maintenance of rickettsiae is very incompletely understood. Some clearly play only the essential role of providing a blood meal to the tick while other hosts may supply crucial supplemental functions for effective agent transmission by the vectors. This review summarizes the importance of some recent findings with known and new vectors that afford an improved understanding of the eco-epidemiology of rickettsiae; the public health implications of that information for rickettsial diseases are also described. Special attention is paid to the co-circulation of different species and genotypes of rickettsiae within the same endemic areas and how these observations may influence, correctly or incorrectly, trends, and conclusions drawn from the surveillance of rickettsial diseases in humans.
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Affiliation(s)
- Marina E Eremeeva
- Jiann-Ping Hsu College of Public Health, Georgia Southern University , Statesboro, GA , USA
| | - Gregory A Dasch
- Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention , Atlanta, GA , USA
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Sakai RK, Costa FB, Ueno TE, Ramirez DG, Soares JF, Fonseca AH, Labruna MB, Barros-Battesti DM. Experimental infection with Rickettsia rickettsii in an Amblyomma dubitatum tick colony, naturally infected by Rickettsia bellii. Ticks Tick Borne Dis 2014; 5:917-23. [DOI: 10.1016/j.ttbdis.2014.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/24/2014] [Accepted: 07/13/2014] [Indexed: 10/24/2022]
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Levin ML, Zemtsova GE, Montgomery M, Killmaster LF. Effects of homologous and heterologous immunization on the reservoir competence of domestic dogs for Rickettsia conorii (israelensis). Ticks Tick Borne Dis 2014; 5:33-40. [PMID: 24201056 PMCID: PMC5659121 DOI: 10.1016/j.ttbdis.2013.07.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 06/24/2013] [Accepted: 07/03/2013] [Indexed: 11/28/2022]
Abstract
A number of spotted fever group (SFG) rickettsiae cause serious infections in humans. Several antigenically related rickettsial agents may coexist within the same geographical area, and humans or vertebrate hosts may be sequentially exposed to multiple SFG agents. We assessed whether exposure of a vertebrate reservoir to one SFG Rickettsia will affect the host's immune response to a related pathogen and the efficiency of transmission to uninfected ticks. Two pairs of dogs were each infected with either Rickettsia massiliae or Rickettsia conorii israelensis, and their immune response was monitored twice weekly by IFA. The four immunized dogs and a pair of naïve dogs were each challenged with R. conorii israelensis-infected Rhipicephalus sanguineus nymphs. Uninfected Rh. sanguineus larvae were acquisition-fed on the dogs on days 1, 7, and 14 post-challenge. These ticks were tested for the presence of rickettsial DNA after molting to the nymphal stage. The naive dogs became infected with R. conorii israelensis and were infectious to ticks for at least 3 weeks, whereas reservoir competence of dogs previously infected with either R. massiliae or R. conorii was significantly diminished. This opens an opportunity for decreasing the efficiency of transmission and propagation of pathogenic Rickettsia in natural foci by immunizing the primary hosts with closely related nonpathogenic SFG bacteria. However, neither homologous immunization nor cross-immunization significantly affected the efficiency of R. conorii transmission between cofeeding infected nymphs and uninfected larvae. At high densities of ticks, the efficiency of cofeeding transmission may be sufficient for yearly amplification and persistent circulation of a rickettsial pathogen in the vector population.
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Affiliation(s)
- M L Levin
- Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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22
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In vitroisolation fromAmblyomma ovale(Acari: Ixodidae) and ecological aspects of the Atlantic rainforestRickettsia, the causative agent of a novel spotted fever rickettsiosis in Brazil. Parasitology 2013; 140:719-28. [DOI: 10.1017/s0031182012002065] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYRecently, a novel human rickettsiosis, namely Atlantic rainforest spotted fever, was described in Brazil. We herein report results of a survey led around the index case in an Atlantic rainforest reserve in Peruibe municipality, southeastern Brazil. ARickettsia parkeri-like agent (Rickettsiasp. Atlantic rainforest genotype) andRicketsia belliiwere isolated from adultAmblyomma ovaleticks collected from dogs. Molecular evidence of infection with strain Atlantic rainforest was obtained for 30 (12·9%) of 232A. ovaleadult ticks collected from dogs. As many as 88·6% of the 35 examined dogs had anti-Rickettsiaantibodies, with endpoint titres at their highest toR. parkeri. High correlation among antibody titres in dogs,A. ovaleinfestations, and access to rainforest was observed.Amblyomma ovalesubadults were found predominantly on a rodent species (Euryoryzomys russatus). From 17E. russatustested, 6 (35·3%) displayed anti-Rickettsiaantibodies, with endpoint titres highest toR. parkeri. It is concluded that Atlantic rainforest genotype circulates in this Atlantic rainforest area at relatively high levels. Dogs get infected when bitten byA. ovaleticks in the forest, and carry infected ticks to households. The role ofE. russatusas an amplifier host ofRickettsiatoA. ovaleticks deserves investigation.
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Renvoisé A, Delaunay P, Blanchouin E, Cannavo I, Cua E, Socolovschi C, Parola P, Raoult D. Urban family cluster of spotted fever rickettsiosis linked to Rhipicephalus sanguineus infected with Rickettsia conorii subsp. caspia and Rickettsia massiliae. Ticks Tick Borne Dis 2012; 3:389-92. [DOI: 10.1016/j.ttbdis.2012.10.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Berrada ZL, Goethert HK, Cunningham J, Telford SR. Rickettsia rickettsii (Rickettsiales: Rickettsiaceae) in Amblyomma americanum (Acari: Ixodidae) from Kansas. JOURNAL OF MEDICAL ENTOMOLOGY 2011; 48:461-467. [PMID: 21485390 DOI: 10.1603/me10130] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The role of lone star ticks as vectors for Rocky Mountain spotted fever (RMSF) remains poorly described. We compared the entomological inoculation rates (EIRs) for Rickettsia spp. for representative sites in Missouri and Kansas, states that frequently report RMSF each year. Host-seeking ticks were collected during 2006 and pooled tick homogenates analyzed by polymerase chain reaction to detect probable R. rickettsii, with confirmation for multiple gene targets performed on individual ticks from pools that screened positive. Of 870 adult and nymphal lone star ticks, Amblyomma americanum (L.), 0.46% contained DNA of Rickettsia rickettsii. Interestingly, two of these positive ticks were concurrently infected by R. amblyommii. More than 90% of lone star tick pools contained R. amblyommii DNA. Of 169 dog ticks that were analyzed, none were infected by R. rickettsii. The entomological inoculation rate for spotted fever group (SFG) rickettsiae within lone star ticks was an order of magnitude greater than that for dog ticks. We conclude that lone star ticks may be epidemiologically significant vectors of Rocky Mountain spotted fever and of spotted fever group rickettsiae.
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Affiliation(s)
- Zenda L Berrada
- Department of Biomedical Sciences, Tufts University Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA
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Stromdahl EY, Jiang J, Vince M, Richards AL. Infrequency of Rickettsia rickettsii in Dermacentor variabilis removed from humans, with comments on the role of other human-biting ticks associated with spotted fever group Rickettsiae in the United States. Vector Borne Zoonotic Dis 2010; 11:969-77. [PMID: 21142953 DOI: 10.1089/vbz.2010.0099] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
From 1997 to 2009, the Tick-Borne Disease Laboratory of the U.S. Army Public Health Command (USAPHC) (formerly the U.S. Army Center for Health Promotion and Preventive Medicine) screened 5286 Dermacentor variabilis ticks removed from Department of Defense (DOD) personnel, their dependents, and DOD civilian personnel for spotted fever group rickettsiae using polymerase chain reaction and restriction fragment length polymorphism analysis. Rickettsia montanensis (171/5286 = 3.2%) and Rickettsia amblyommii (7/5286 = 0.1%) were detected in a small number of samples, but no ticks were found positive for Rickettsia rickettsii, the agent of Rocky Mountain spotted fever (RMSF) until May 2009, when it was detected in one D. variabilis male removed from a child in Maryland. This result was confirmed by nucleotide sequence analysis of the rickettsial isolate and of the positive control used in the polymerase chain reaction, which was different from the isolate. Lethal effects of rickettsiostatic proteins of D. variabilis on R. rickettsii and lethal effects of R. rickettsii infection on tick hosts may account for this extremely low prevalence. Recent reports of R. rickettsii in species Rhipicephalus sanguineus and Amblyomma americanum ticks suggest their involvement in transmission of RMSF, and other pathogenic rickettsiae have been detected in Amblyomma maculatum. The areas of the U.S. endemic for RMSF are also those where D. variabilis exist in sympatry with populations of A. americanum and A. maculatum. Interactions among the sympatric species of ticks may be involved in the development of a focus of RMSF transmission. On the other hand, the overlap of foci of RMSF cases and areas of A. americanum and A. maculatum populations might indicate the misdiagnosis as RMSF of diseases actually caused by other rickettsiae vectored by these ticks. Further studies on tick vectors are needed to elucidate the etiology of RMSF.
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Affiliation(s)
- Ellen Y Stromdahl
- Entomological Sciences Program, US Army Public Health Command, Aberdeen Proving Ground, Maryland 21010–5403, USA.
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Wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods. Appl Environ Microbiol 2010; 76:1718-31. [PMID: 20097813 DOI: 10.1128/aem.02988-09] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. We report the existence of plasmids in Rickettsia (Rickettsiales; Rickettsiaceae) species, including Rickettsia akari, "Candidatus Rickettsia amblyommii," R. bellii, R. rhipicephali, and REIS, the rickettsial endosymbiont of Ixodes scapularis. All of the rickettsiae were isolated from humans or North and South American ticks. R. parkeri isolates from both continents did not possess plasmids. We have now demonstrated plasmids in nearly all Rickettsia species that we have surveyed from three continents, which represent three of the four major proposed phylogenetic groups associated with blood-feeding arthropods. Gel-based evidence consistent with the existence of multiple plasmids in some species was confirmed by cloning plasmids with very different sequences from each of two "Ca. Rickettsia amblyommii" isolates. Phylogenetic analysis of rickettsial ParA plasmid partitioning proteins indicated multiple parA gene origins and plasmid incompatibility groups, consistent with possible multiple plasmid origins. Phylogenetic analysis of potentially host-adaptive rickettsial small heat shock proteins showed that hsp2 genes were plasmid specific and that hsp1 genes, found only on plasmids of "Ca. Rickettsia amblyommii," R. felis, R. monacensis, and R. peacockii, were probably acquired independently of the hsp2 genes. Plasmid copy numbers in seven Rickettsia species ranged from 2.4 to 9.2 per chromosomal equivalent, as determined by real-time quantitative PCR. Plasmids may be of significance in rickettsial evolution and epidemiology by conferring genetic plasticity and host-adaptive traits via horizontal gene transfer that counteracts the reductive genome evolution typical of obligate intracellular bacteria.
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