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Wang Q, Ma T, Ding F, Lim A, Takaya S, Saraswati K, Sartorius B, Day NPJ, Maude RJ. Global and regional seroprevalence, incidence, mortality of, and risk factors for scrub typhus: A systematic review and meta-analysis. Int J Infect Dis 2024; 146:107151. [PMID: 38964725 DOI: 10.1016/j.ijid.2024.107151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/28/2024] [Accepted: 06/20/2024] [Indexed: 07/06/2024] Open
Abstract
OBJECTIVES Scrub typhus is underdiagnosed and underreported but emerging as a global public health problem. We aimed to provide the first comprehensive review on the seroprevalence, incidence, mortality of and risk factors for scrub typhus. METHODS We searched PubMed, Scopus, Web of Science, China National Knowledge Infrastructure and other databases. Trended incidence and median mortality were calculated and pooled seroprevalence and risk factors for scrub typhus were evaluated using the random-effects meta-analysis. RESULTS We included 663 articles from 29 countries/regions. The pooled seroprevalence was 10.73% (95%CI 9.47-12.13%) among healthy individuals and 22.58% (95%CI: 20.55%-24.76%) among febrile patients. Mainland China reported the highest number of cases and South Korea and Thailand had the highest incidence rates. Median mortalities were 5.00% (range: 0.00-56.00%) among hospital inpatients, 6.70% (range: 0.00-33.33%) among patients without specified admission status and 2.17% (range: 0.00-22.22%) among outpatients. The significant risk factors included agricultural work, specific vegetation exposure, other outdoor activities, risky personal health habits, and proximity to rodents, livestock, or poultry. CONCLUSIONS Our comprehensive review elucidates the significant yet variable burden of scrub typhus across different regions, underscoring its emergence as a critical public health concern globally.
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Affiliation(s)
- Qian Wang
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Tian Ma
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Fangyu Ding
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Ahyoung Lim
- London School of Hygiene & Tropical Medicine, London, UK
| | - Saho Takaya
- London School of Hygiene & Tropical Medicine, London, UK
| | - Kartika Saraswati
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore; Oxford University Clinical Research Unit Indonesia, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Benn Sartorius
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Centre for Clinical Research (UQCCR), Faculty of Medicine, University of Queensland, Brisbane, Australia; Department of Health Metric Sciences, School of Medicine, University of Washington, Seattle, USA
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Richard J Maude
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; The Open University, Milton Keynes, UK
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Lu H, Li J, Fan R, Hao G, Sun M, Liang Y. First laboratory-confirmed case of scrub typhus in Shijiazhuang City, Hebei Province. Front Microbiol 2024; 15:1409949. [PMID: 38855771 PMCID: PMC11157097 DOI: 10.3389/fmicb.2024.1409949] [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] [Received: 03/31/2024] [Accepted: 05/14/2024] [Indexed: 06/11/2024] Open
Abstract
Objective Defining whether a suspected case was due to scrub typhus through laboratory testing, to understand the prevalence of scrub typhus in Shijiazhuang City, Hebei Province. Methods An epidemiological investigation was conducted on the suspected case, utilizing Weil-Felix test and indirect immunofluorescence assay (IFA) to detect specific antibodies against O. tsutsugamushi in serum specimens. Additionally, PCR amplification of the 56-kDa and groEL genes was performed, followed by constructing a phylogenetic tree to identify the genotype. Results The acute phase titer of the Weil-Felix test for the case was 1:160, which increased to 1:320 in the recovery phase. IFA assay revealed IgG titers against O. tsutsugamushi of 1:64 in the acute phase and 1:256 in the recovery phase. Sequence alignment of the PCR amplified fragment showed the highest similarity with the O. tsutsugamushi genotype. Kawasaki sequence, ranging from 99.71 to 100.00%. The strain exhibited the closest genetic relationship with the known O. tsutsugamushi Kawasaki genotype. Conclusion This study confirms the presence of O. tsutsugamushi in Shijiazhuang City, Hebei Province, with the identified strain belonging to the Kawasaki genotype, marking the first diagnosis of this strain in the region.
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Affiliation(s)
- Huixiu Lu
- Department of Dermatology, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
| | - Jianying Li
- Department of Dermatology, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
| | - Rong Fan
- Department of Laboratory Medicine, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
| | - Gaoyuan Hao
- Department of Dermatology, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
| | - Meilan Sun
- Department of Dermatology, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
| | - Yunchuan Liang
- Department of Dermatology, Shijiazhuang People’s Hospital, Shijiazhuang City, Hebei, China
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Saraswati K, Tanganuchitcharnchai A, Ongchaikupt S, Mukaka M, Day NPJ, Baird JK, Antonjaya U, Myint KSA, Dewi YP, Yudhaputri FA, Haryanto S, Witari NPD, Blacksell SD. Scrub typhus in Indonesia: A cross-sectional analysis of archived fever studies samples. Trans R Soc Trop Med Hyg 2024; 118:321-327. [PMID: 38205975 PMCID: PMC11062201 DOI: 10.1093/trstmh/trad094] [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: 08/11/2023] [Revised: 11/06/2023] [Accepted: 12/16/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Scrub typhus is an understudied vector-borne bacterial infection. METHODS We tested archived fever samples for scrub typhus seropositivity to begin charting its geographic distribution in Indonesia. We analysed 1033 serum samples from three sites. IgM and IgG enzyme-linked immunosorbent assay (ELISA) against Orientia tsutsugamushi was performed using Karp, Kato, Gilliam, TA 716 antigens. To determine the cutoff in the absence of a presumed unexposed population and gold standard tests, we identified the visual inflection point, performed change point analysis, and used finite mixture models. RESULTS The optical density cutoff values used for IgM and IgG were 0.49 and 0.13, respectively. Across all sites, IgM seropositivity was 4.6% (95% CI: 3.4 to 6.0%) while IgG seropositivity was 4.4% (95% CI: 3.3 to 5.8%). The overall seropositivity across sites was 8.8% (95% CI: 8.1 to 11.7%). The overall seropositivity for Jambi, Denpasar, Tabanan were 9.7% (95% CI: 7.0 to 13.3%), 8.0% (95% CI: 5.7 to 11.0%), 9.0% (95% CI: 6.1 to 13.0%), respectively. CONCLUSIONS We conclude that O. tsutsugamushi exposure in humans occurred at all sites analysed and could be the cause of illness in some cases. Though it was not the main cause of acute fever in these locations, it is still important to consider scrub typhus in cases not responding to beta-lactam antibiotics. Future seroprevalence surveys and testing for scrub typhus in acute febrile illness studies will be essential to understand its distribution and burden in Indonesia.
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Affiliation(s)
- Kartika Saraswati
- Oxford University Clinical Research Unit Indonesia, Faculty of Medicine, Universitas Indonesia, 10430 Jakarta, Indonesia
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, OX3 7LG Oxford, UK
| | - Ampai Tanganuchitcharnchai
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
| | - Sirada Ongchaikupt
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, OX3 7LG Oxford, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, OX3 7LG Oxford, UK
| | - J Kevin Baird
- Oxford University Clinical Research Unit Indonesia, Faculty of Medicine, Universitas Indonesia, 10430 Jakarta, Indonesia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, OX3 7LG Oxford, UK
| | - Ungke Antonjaya
- Oxford University Clinical Research Unit Indonesia, Faculty of Medicine, Universitas Indonesia, 10430 Jakarta, Indonesia
| | | | - Yora P Dewi
- Exeins Health Initiative, 12870 Jakarta, Indonesia
| | | | - Sotianingsih Haryanto
- Raden Mattaher Hospital, 36122 Jambi, Indonesia
- Faculty of Medicine and Health Sciences, Universitas Jambi, 36361 Jambi, Indonesia
| | - N P Diah Witari
- Faculty of Medicine and Health Sciences, Warmadewa University, 80235 Denpasar, Bali, Indonesia
| | - Stuart D Blacksell
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400 Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, OX3 7LG Oxford, UK
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Alkathiry HA, Alghamdi SQ, Sinha A, Margos G, Stekolnikov AA, Alagaili AN, Darby AC, Makepeace BL, Khoo JJ. Microbiome and mitogenomics of the chigger mite Pentidionis agamae: potential role as an Orientia vector and associations with divergent clades of Wolbachia and Borrelia. BMC Genomics 2024; 25:380. [PMID: 38632506 PMCID: PMC11025265 DOI: 10.1186/s12864-024-10301-6] [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: 01/05/2024] [Accepted: 04/11/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Trombiculid mites are globally distributed, highly diverse arachnids that largely lack molecular resources such as whole mitogenomes for the elucidation of taxonomic relationships. Trombiculid larvae (chiggers) parasitise vertebrates and can transmit bacteria (Orientia spp.) responsible for scrub typhus, a zoonotic febrile illness. Orientia tsutsugamushi causes most cases of scrub typhus and is endemic to the Asia-Pacific Region, where it is transmitted by Leptotrombidium spp. chiggers. However, in Dubai, Candidatus Orientia chuto was isolated from a case of scrub typhus and is also known to circulate among rodents in Saudi Arabia and Kenya, although its vectors remain poorly defined. In addition to Orientia, chiggers are often infected with other potential pathogens or arthropod-specific endosymbionts, but their significance for trombiculid biology and public health is unclear. RESULTS Ten chigger species were collected from rodents in southwestern Saudi Arabia. Chiggers were pooled according to species and screened for Orientia DNA by PCR. Two species (Microtrombicula muhaylensis and Pentidionis agamae) produced positive results for the htrA gene, although Ca. Orientia chuto DNA was confirmed by Sanger sequencing only in P. agamae. Metagenomic sequencing of three pools of P. agamae provided evidence for two other bacterial associates: a spirochaete and a Wolbachia symbiont. Phylogenetic analysis of 16S rRNA and multi-locus sequence typing genes placed the spirochaete in a clade of micromammal-associated Borrelia spp. that are widely-distributed globally with no known vector. For the Wolbachia symbiont, a genome assembly was obtained that allowed phylogenetic localisation in a novel, divergent clade. Cytochrome c oxidase I (COI) barcodes for Saudi Arabian chiggers enabled comparisons with global chigger diversity, revealing several cases of discordance with classical taxonomy. Complete mitogenome assemblies were obtained for the three P. agamae pools and almost 50 SNPs were identified, despite a common geographic origin. CONCLUSIONS P. agamae was identified as a potential vector of Ca. Orientia chuto on the Arabian Peninsula. The detection of an unusual Borrelia sp. and a divergent Wolbachia symbiont in P. agamae indicated links with chigger microbiomes in other parts of the world, while COI barcoding and mitogenomic analyses greatly extended our understanding of inter- and intraspecific relationships in trombiculid mites.
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Affiliation(s)
- Hadil A Alkathiry
- Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Samia Q Alghamdi
- Department of Biology, Faculty of Science, Al-Baha University, P.O.Box1988, Al-Baha, 65799, Saudi Arabia
| | - Amit Sinha
- New England Biolabs, Ipswich, Massachusetts, 01938, USA
| | - Gabriele Margos
- National Reference Centre for Borrelia, Bavarian Health and Food Safety Authority, Veterinärstr. 2, Oberschleissheim, 85764, Germany
| | - Alexandr A Stekolnikov
- Laboratory of Parasitic Arthropods, Zoological Institute of the Russian Academy of Sciences, Universitetskaya embankment 1, St. Petersburg, 199034, Russia
| | | | - Alistair C Darby
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Jing Jing Khoo
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK.
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Minahan NT, Yen TY, Guo YLL, Shu PY, Tsai KH. Concatenated ScaA and TSA56 Surface Antigen Sequences Reflect Genome-Scale Phylogeny of Orientia tsutsugamushi: An Analysis Including Two Genomes from Taiwan. Pathogens 2024; 13:299. [PMID: 38668254 PMCID: PMC11054523 DOI: 10.3390/pathogens13040299] [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: 03/08/2024] [Revised: 03/29/2024] [Accepted: 03/29/2024] [Indexed: 04/29/2024] Open
Abstract
Orientia tsutsugamushi is an obligate intracellular bacterium associated with trombiculid mites and is the causative agent of scrub typhus, a life-threatening febrile disease. Strain typing of O. tsutsugamushi is based on its immunodominant surface antigen, 56-kDa type-specific antigen (TSA56). However, TSA56 gene sequence-based phylogenetic analysis is only partially congruent with core genome-based phylogenetic analysis. Thus, this study investigated whether concatenated surface antigen sequences, including surface cell antigen (Sca) proteins, can reflect the genome-scale phylogeny of O. tsutsugamushi. Complete genomes were obtained for two common O. tsutsugamushi strains in Taiwan, TW-1 and TW-22, and the core genome/proteome was identified for 11 O. tsutsugamushi strains. Phylogenetic analysis was performed using maximum likelihood (ML) and neighbor-joining (NJ) methods, and the congruence between trees was assessed using a quartet similarity measure. Phylogenetic analysis based on 691 concatenated core protein sequences produced identical tree topologies with ML and NJ methods. Among TSA56 and core Sca proteins (ScaA, ScaC, ScaD, and ScaE), TSA56 trees were most similar to the core protein tree, and ScaA trees were the least similar. However, concatenated ScaA and TSA56 sequences produced trees that were highly similar to the core protein tree, the NJ tree being more similar. Strain-level characterization of O. tsutsugamushi may be improved by coanalyzing ScaA and TSA56 sequences, which are also important targets for their combined immunogenicity.
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Affiliation(s)
- Nicholas T. Minahan
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei 100025, Taiwan; (N.T.M.); (Y.-L.L.G.)
| | - Tsai-Ying Yen
- Centers for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei 115210, Taiwan; (T.-Y.Y.); (P.-Y.S.)
| | - Yue-Liang Leon Guo
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei 100025, Taiwan; (N.T.M.); (Y.-L.L.G.)
- Department of Environmental and Occupational Medicine, National Taiwan University (NTU) College of Medicine and NTU Hospital, Taipei 100025, Taiwan
| | - Pei-Yun Shu
- Centers for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei 115210, Taiwan; (T.-Y.Y.); (P.-Y.S.)
| | - Kun-Hsien Tsai
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei 100025, Taiwan; (N.T.M.); (Y.-L.L.G.)
- Global Health Program, College of Public Health, National Taiwan University, Taipei 100025, Taiwan
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Bhardwaj P, Nanaware NS, Behera SP, Kulkarni S, Deval H, Kumar R, Dwivedi GR, Kant R, Singh R. CRISPR/Cas12a-Based Detection Platform for Early and Rapid Diagnosis of Scrub Typhus. BIOSENSORS 2023; 13:1021. [PMID: 38131781 PMCID: PMC10742217 DOI: 10.3390/bios13121021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 12/23/2023]
Abstract
Orientia tsutsugamushi is responsible for causing scrub typhus (ST) and is the leading cause of acute encephalitis syndrome (AES) in AES patients. A rapid and sensitive method to detect scrub typhus on-site is essential for the timely deployment of control measures. In the current study, we developed a rapid, sensitive, and instrument-free lateral flow assay (LFA) detection method based on CRISPR/Cas12a technology for diagnosing ST (named LoCIST). The method is completed in three steps: first, harnessing the ability of recombinase polymerase for isothermal amplification of the target gene; second, CRISPR/Cas12a-based recognition of the target; and third, end-point detection by LFA. The detection limit of LoCIST was found to be one gene copy of ST genomic DNA per reaction, and the process was complete within an hour. In 81 clinical samples, the assay showed no cross-reactivity with other rickettsial DNA and was 100% consistent with PCR detection of ST. LoCIST demonstrated 97.6% sensitivity and 100% specificity. Overall, the LoCIST offers a novel alternative for the portable, simple, sensitive, and specific detection of ST, and it may help prevent and control AES outbreaks due to ST. In conclusion, LoCIST does not require specialized equipment and poses a potential for future applications as a point-of-care diagnostic.
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Affiliation(s)
- Pooja Bhardwaj
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
| | | | - Sthita Pragnya Behera
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
| | - Smita Kulkarni
- ICMR-National AIDS Research Institute, Bhosari, Pune 411026, India; (N.S.N.); (S.K.)
| | - Hirawati Deval
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
| | - Rajesh Kumar
- RGSC, Department of Genetics and Plant Breeding, Banaras Hindu University, Varanasi 221005, India;
| | - Gaurav Raj Dwivedi
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
| | - Rajni Kant
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
| | - Rajeev Singh
- ICMR-Regional Medical Research Centre Gorakhpur, BRD Medical College Campus, Gorakhpur 273013, India; (P.B.); (S.P.B.); (H.D.); (G.R.D.); (R.K.)
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Zhang Y, Hai Y, Duan B, Long H, Xie X, Teng Z, Yin F, Wang M, Xiong Y, Shao Z, Guo W, Qin A. A seminested recombinase polymerase amplification assay to detect rickettsial pathogens in clinical samples. Diagn Microbiol Infect Dis 2023; 107:116067. [PMID: 37751629 DOI: 10.1016/j.diagmicrobio.2023.116067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023]
Abstract
Treatment at the early stage of onset is vital for the prognosis of rickettsioses. But the absence of specific clinical symptoms complicates the diagnosis of this condition. Herein we established a seminested recombinase polymerase amplification assay (snRPA-nfo) that enables quick detection and differentiation of rickettsial pathogens in clinical samples with high sensitivity and specificity. The conserved 17-kDa protein gene of Rickettsia sibirica and the 47-kDa protein gene of Orientia tsutsugamushi were targeted for the duplex RPA-nfo assay. The snRPA-nfo assay exhibited an increased LOD in spiked blood samples, up to 1000-fold in comparison to standard RPA-nfo, and a better detection rate (83.3%, 5/6) than TaqMan PCR (16.6%, 1/6, Ct ≤ 35) in clinically confirmed patient blood samples. Thus, snRPA-nfo assay represents a promising alternative to TaqMan PCR in the early diagnosis of rickettsioses for point-of-care testing as well as in resource-limited settings.
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Affiliation(s)
- Ying Zhang
- Center for Disease Control and Prevention of Xilingol League, Xilinhaote, Inner Mongolia, China; State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yan Hai
- Center for Disease Control and Prevention of Inner Mongolia, Hohhot, Inner Mongolia, China
| | - Biao Duan
- Institute of Endemic Diseases Control and Prevention of Yunnan, Dali, Yunnan, China
| | - Hu Long
- Center for Disease Control and Prevention of Guilin City, Guilin, Guangxi, China
| | - Xiaofei Xie
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China; Hainan Medical College, Haikou, Hainan, China
| | - Zhongqiu Teng
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Feifei Yin
- Hainan Medical College, Haikou, Hainan, China
| | - Mingliu Wang
- Center for Disease Control and Prevention of Guangxi, Nanning, Guangxi, China
| | - Yanwen Xiong
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhujun Shao
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Weidong Guo
- Center for Disease Control and Prevention of Xilingol League, Xilinhaote, Inner Mongolia, China; Institute of Endemic Diseases Control and Prevention of Yunnan, Dali, Yunnan, China.
| | - Aiping Qin
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
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8
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Wang YC, Li JH, Qin Y, Qin SY, Chen C, Yang XB, Ma N, Dong MX, Lei CC, Yang X, Sun HT, Sun ZY, Jiang J. The Prevalence of Rodents Orientia tsutsugamushi in China During Two Decades: A Systematic Review and Meta-Analysis. Vector Borne Zoonotic Dis 2023; 23:619-633. [PMID: 37625029 DOI: 10.1089/vbz.2023.0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2023] Open
Abstract
Background: Orientia tsutsugamushi is a zoonotic intracellular pathogen that requires parasitism in eukaryotic cells to reproduce. In recent years, tsutsugamushi disease reported in many places nationwide has crossed the Yangtze River, continuously, spreading to the North China. Now this phenomenon has aroused people's attention. Materials and Methods: In this study, meta-analysis was used to analyze the infection of rodents (vectors) in China, to clarify the transmission rule of O. tsutsugamushi. Results: This study included literature from six databases (PubMed, Web of Science, Science Direct, Wanfang, CNKI, and VIP). A total of 55 articles were included in the study from 610 retrieved articles. The total infection rate of O. tsutsugamushi in rodents was 5.5% (1206/20,620, 95% confidence interval [CI]: 0.0553-0.0617). The prevalence of O. tsutsugamushi in rodents before 2013 (7.73%, 95% CI: 4.11-12.37) was higher than after 2013 (2.11%, 95% CI: 0.64-4.41). O. tsutsugamushi spread among a variety of rodents, among which Rattus losea (13.3%, 95% CI: 4.33-26.26), Rattus tanezumi (5.69%, 95% CI: 1.37-12.72), and Apodemus agrarius (5.32%, 95% CI: 2.26-9.58) infection rate was higher. Kawasaki (8.32%, 95% CI: 1.42-20.17), Karp (7.36%, 95% CI: 2.62-14.22), Kato (2.54%, 95% CI: 0.08-8.28), and Gilliam (2.13%, 95% CI: 0.42-5.09) were the main prevalent genotypes in China. The prevalence of O. tsutsugamushi in rodents was seasonal, increasing gradually in summer (2.39%, 95% CI: 0.46-5.77), peaking in autumn (4.59%, 95% CI: 1.15-10.16), and then declining. The positive rate of immunofluorescence assay (25.07%, 95% CI: 8.44-46.88) was the highest among the detection methods, and it was statistically significant (p < 0.05). Based on the subgroup of geographical factors and climatic factors, the probability of O. tsutsugamushi infection in rodents was the highest when the temperature >19℃ (8.20%, 95% CI: 1.22-20.52), the altitude <100 millimeters (7.23%, 95% CI: 3.45-12.26), the precipitation >700 millimeters (12.22%, 95% CI: 6.45-19.50), and the humidity 60-70% (7.80%, 95% CI: 4.17-12.44). Conclusions: Studies have shown that rodents carrying O. tsutsugamushi are common. People should prevent and control rodents in life and monitor rodents carrying O. tsutsugamushi for a long time.
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Affiliation(s)
- Yan-Chun Wang
- School of Pharmacy, Qingdao University, Qingdao, PR China
- Changchun Sci-Tech University, Shuangyang, PR China
- Department of Technology, Ningbo Sansheng Biotechnology Co., Ltd, Ningbo, PR China
| | - Jing-Hao Li
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, PR China
| | - Ya Qin
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Si-Yuan Qin
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, PR China
| | - Chao Chen
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Xin-Bo Yang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Ning Ma
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Ming-Xin Dong
- School of Pharmacy, Qingdao University, Qingdao, PR China
- Department of Technology, Ningbo Sansheng Biotechnology Co., Ltd, Ningbo, PR China
| | - Cong-Cong Lei
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, PR China
| | - Xing Yang
- Department of Medical Microbiology and Immunology, School of Basic Medicine, Dali University, Dali, PR China
| | - He-Ting Sun
- Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, PR China
| | - Zhi-Yong Sun
- Department of Technology, Ningbo Sansheng Biotechnology Co., Ltd, Ningbo, PR China
| | - Jing Jiang
- Changchun Sci-Tech University, Shuangyang, PR China
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9
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Silva-Ramos CR, Faccini-Martínez ÁA, Serna-Rivera CC, Mattar S, Hidalgo M. Etiologies of Zoonotic Tropical Febrile Illnesses That Are Not Part of the Notifiable Diseases in Colombia. Microorganisms 2023; 11:2154. [PMID: 37763998 PMCID: PMC10535066 DOI: 10.3390/microorganisms11092154] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/15/2023] [Accepted: 06/15/2023] [Indexed: 09/29/2023] Open
Abstract
In Colombia, tropical febrile illnesses represent one of the most important causes of clinical attention. Febrile illnesses in the tropics are mainly zoonotic and have a broad etiology. The Colombian surveillance system monitors some notifiable diseases. However, several etiologies are not monitored by this system. In the present review, we describe eleven different etiologies of zoonotic tropical febrile illnesses that are not monitored by the Colombian surveillance system but have scientific, historical, and contemporary data that confirm or suggest their presence in different regions of the country: Anaplasma, Arenavirus, Bartonella, relapsing fever group Borrelia, Coxiella burnetii, Ehrlichia, Hantavirus, Mayaro virus, Orientia, Oropouche virus, and Rickettsia. These could generate a risk for the local population, travelers, and immigrants, due to which they should be included in the mandatory notification system, considering their importance for Colombian public health.
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Affiliation(s)
- Carlos Ramiro Silva-Ramos
- Grupo de Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia;
| | - Álvaro A. Faccini-Martínez
- Servicio de Infectología, Hospital Militar Central, Bogotá 110110, Colombia;
- Servicios y Asesorías en Infectología—SAI, Bogotá 110110, Colombia
| | - Cristian C. Serna-Rivera
- Grupo de Investigación en Ciencias Veterinarias (CENTAURO), Línea de Investigación Zoonosis Emergentes y Re-Emergentes, Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellín 050034, Colombia;
- Grupo de Investigación en Genética, Biodiversidad y Manejo de Ecosistemas (GEBIOME), Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Manizales 170004, Colombia
| | - Salim Mattar
- Instituto de Investigaciones Biológicas del Trópico, Universidad de Córdoba, Montería 230001, Colombia;
| | - Marylin Hidalgo
- Grupo de Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá 110231, Colombia;
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10
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Chen K, Travanty NV, Garshong R, Crossley D, Wasserberg G, Apperson CS, Roe RM, Ponnusamy L. Detection of Orientia spp. Bacteria in Field-Collected Free-Living Eutrombicula Chigger Mites, United States. Emerg Infect Dis 2023; 29:1676-1679. [PMID: 37486323 PMCID: PMC10370866 DOI: 10.3201/eid2908.230528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023] Open
Abstract
Scrub typhus, a rickettsial disease caused by Orientia spp., is transmitted by infected larval trombiculid mites (chiggers). We report the molecular detection of Orientia species in free-living Eutrombicula chiggers collected in an area in North Carolina, USA, to which spotted fever group rickettsiae infections are endemic.
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11
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Chaisiri K, Linsuwanon P, Makepeace BL. The chigger microbiome: big questions in a tiny world. Trends Parasitol 2023; 39:696-707. [PMID: 37270375 DOI: 10.1016/j.pt.2023.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 05/06/2023] [Accepted: 05/09/2023] [Indexed: 06/05/2023]
Abstract
'Chiggers' (trombiculid mite larvae) are best known as vectors of rickettsial pathogens, Orientia spp., which cause a zoonosis, scrub typhus. However, several other pathogens (e.g., Hantaan orthohantavirus, Dabie bandavirus, Anaplasma spp., Bartonella spp., Borrelia spp., and Rickettsia spp.) and bacterial symbionts (e.g., Cardinium, Rickettsiella, and Wolbachia) are being reported from chiggers with increasing frequency. Here, we explore the surprisingly diverse chigger microbiota and potential interactions within this microcosm. Key conclusions include a possible role for chiggers as vectors of viral diseases; the dominance in some chigger populations of unidentified symbionts in several bacterial families; and increasing evidence for vertical transmission of potential pathogens and symbiotic bacteria in chiggers, suggesting intimate interactions and not simply incidental acquisition of bacteria from the environment or host.
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Affiliation(s)
- Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok 10400, Thailand
| | - Piyada Linsuwanon
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok 10400, Thailand
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK.
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12
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Weitzel T, Martínez-Valdebenito C, Acosta-Jamett G, Abarca K. Notes from the Field: Scrub Typhus Outbreak - Los Lagos Region, Chile, January-February 2023. MMWR. MORBIDITY AND MORTALITY WEEKLY REPORT 2023; 72:753-754. [PMID: 37410667 PMCID: PMC10328483 DOI: 10.15585/mmwr.mm7227a4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
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13
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Gillespie JJ, Salje J. Orientia and Rickettsia: different flowers from the same garden. Curr Opin Microbiol 2023; 74:102318. [PMID: 37080115 DOI: 10.1016/j.mib.2023.102318] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/22/2023]
Abstract
Recent discoveries of basal extracellular Rickettsiales have illuminated divergent evolutionary paths to host dependency in later-evolving lineages. Family Rickettsiaceae, primarily comprised of numerous protist- and invertebrate-associated species, also includes human pathogens from two genera, Orientia and Rickettsia. Once considered sister taxa, these bacteria form distinct lineages with newly appreciated lifestyles and morphological traits. Contrasting other rickettsial human pathogens in Family Anaplasmataceae, Orientia and Rickettsia species do not reside in host-derived vacuoles and lack glycolytic potential. With only a few described mechanisms, strategies for commandeering host glycolysis to support cytosolic growth remain to be discovered. While regulatory systems for this unique mode of intracellular parasitism are unclear, conjugative transposons unique to Orientia and Rickettsia species provide insights that are critical for determining how these obligate intracellular pathogens overtake eukaryotic cytosol.
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Affiliation(s)
- Joseph J Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, USA.
| | - Jeanne Salje
- Department of Biochemistry, Department of Pathology, and Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK.
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14
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Bhardwaj P, Behera SP, Nanaware N, Zaman K, Deval H, Kant R, Kulkarni S, Kumar R, Dwivedi GR, Singh R. Phylogenetic and immunological investigations of complete TSA56 ORF of Orientia tsutsugamushi present in acute encephalitis syndrome cases from eastern Uttar Pradesh, India. Arch Microbiol 2023; 205:178. [PMID: 37029825 PMCID: PMC10082565 DOI: 10.1007/s00203-023-03492-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 04/09/2023]
Abstract
Scrub typhus (ST) caused by Orientia tsutsugamushi (OT), has long been known to cause acute encephalitis syndrome (AES) and acute febrile illness (AFI). The immunodominant 56 kDa protein of OT, which is encoded by the 56 kDa gene (1600 bp encoding 516-541 amino acids) is a commonly studied antigen for genotype and serotype assignment. Previous studies from India have utilized partial type specific antigen (TSA) 56 kDa sequences for OT strain characterisation. On the other hand, understanding the antigenic diversity of current OT strains, is critical for developing specific diagnostic tests and vaccines against ST. As a result, the current study analyses antigenic variants using the entire TSA56 ORF of OT from AES cases. Phylogenetic investigation using complete TSA56 ORF sequences revealed Karp and Gilliam were the circulating predominant strains of OT. Furthermore, Immuno-informatical analysis demonstrated that the majority of high-binding affinity CD4 TCEs against the most prevalent Indian human leukocyte antigen alleles were present in the S-VDIII/IV and S-VDIV spacer regions of TSA56 ORF. TSA56 conserved spacer is crucial for OT immunological response investigations. Further, the pathophysiological effects of spacer domains in ST require further investigation. Furthermore, the characterization of the TSA56 spacer region of the OT from different parts of India is critical for developing region-specific ST diagnostic assays and vaccines.
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Affiliation(s)
- Pooja Bhardwaj
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Sthita Pragnya Behera
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Nikita Nanaware
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India
| | - Kamran Zaman
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnatka, India
| | - Hirawati Deval
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajni Kant
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Smita Kulkarni
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India
| | - Rajesh Kumar
- RGSC, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India
| | - Gaurav Raj Dwivedi
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajeev Singh
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India.
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15
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Nallan K, Rajan G, Sivathanu L, Devaraju P, Thiruppathi B, Kumar A, Rajaiah P. Molecular Detection of Multiple Genotypes of Orientia tsutsugamushi Causing Scrub Typhus in Febrile Patients from Theni District, South India. Trop Med Infect Dis 2023; 8:tropicalmed8030174. [PMID: 36977175 PMCID: PMC10058992 DOI: 10.3390/tropicalmed8030174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Scrub typhus (St) is a re-emerging mite-transmitted public health problem in Southeast Asia with escalating case incidences in the endemic areas. Though, more than 40 genotypes of the causative agent Orientia tsutsugamushi (Ot) have been documented, the information on the circulating genotypes in India is scanty. A hospital-based retrospective screening was undertaken to map the circulating molecular subtypes of the etiological agent in serologically confirmed scrub typhus (St) human cases, by targeting the GroEL gene of O. tsutsugamushi using the nested polymerase chain reaction method. Nine out of 34 samples (26%) yielded positive results and DNA sequencing analysis of six positive samples out of nine revealed that the sequences were related to three major genotypes, such as Karp (HSB1, FAR1), Kato (Wuj/2014, UT76), and Kawasaki (Kuroki, Boryong, Gilliam, and Hwasung). Additionally, the St-positive samples exhibited 100% and 99.45%; 97.53% and 97.81%; 96.99% nucleotide identity with the closely related Karp, Kato, and Kawasaki-related sequences, respectively. Overall, 94% of the nucleotides were conserved, and the variable site was 20/365 (5.5%). The prevalence of multiple genotypes among human cases further stresses the need to conduct in-depth studies to map the genotypes and their clinical relevance, and the contributing risk factors for the emergence of St cases in this area.
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Affiliation(s)
| | - Gopinathan Rajan
- Department of Microbiology, Government Medical College and Hospital, Theni 625 512, India
| | - Lallitha Sivathanu
- Department of Microbiology, Government Medical College and Hospital, Theni 625 512, India
| | | | | | - Ashwani Kumar
- ICMR-Vector Control Research Centre, Puducherry 605 006, India
| | - Paramasivan Rajaiah
- ICMR-Vector Control Research Centre, Field Unit, Madurai 625 002, India
- Correspondence: ; Tel.: +91-9442026705 or +91-4522525131
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16
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Walker DH, Blanton LS. Progress in Treating a Neglected Tropical Disease. N Engl J Med 2023; 388:843-844. [PMID: 36856622 DOI: 10.1056/nejme2300113] [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: 03/02/2023]
Affiliation(s)
- David H Walker
- From the Departments of Pathology (D.H.W.) and Internal Medicine (L.S.B.), the Center for Biodefense and Emerging Infectious Diseases, the Center for Tropical Diseases, and the Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston
| | - Lucas S Blanton
- From the Departments of Pathology (D.H.W.) and Internal Medicine (L.S.B.), the Center for Biodefense and Emerging Infectious Diseases, the Center for Tropical Diseases, and the Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston
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17
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An Alternative Splicing Variant of the Mixed-Lineage Leukemia 5 Protein Is a Cellular Adhesion Receptor for ScaA of Orientia tsutsugamushi. mBio 2023; 14:e0154322. [PMID: 36541760 PMCID: PMC9973269 DOI: 10.1128/mbio.01543-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus is a mite-borne disease caused by the obligately intracellular bacterium Orientia tsutsugamushi. We previously demonstrated that ScaA, an autotransporter membrane protein of O. tsutsugamushi, is commonly shared in various genotypes and involved in adherence to host cells. Here, we identified a mixed-lineage leukemia 5 (MLL5) mammalian trithorax group protein as a host receptor that interacts with ScaA. MLL5, identified by yeast two-hybrid screening, is an alternative splicing variant of MLL5 (vMLL5) which contains 13 exons with additional intron sequences encoding a tentative transmembrane domain. Indeed, vMLL5 is expressed on the plasma membrane as well as in intracellular compartments in eukaryotic cells and colocalized with adherent O. tsutsugamushi. In addition, ScaA-expressing Escherichia coli showed significantly increased adherence to vMLL5-overexpressing cells compared with vector control cells. We mapped the C-terminal region of the passenger domain of ScaA as a ligand for vMLL5 and determined that the Su(var)3-9, Enhancer of zeste, Trithorax (SET) domain of MLL5 is an essential and sufficient motif for ScaA binding. We observed significant and specific inhibition of bacterial adhesion to host cells in competitive inhibition assays using the C-terminal fragment of ScaA or the SET domain of vMLL5. Moreover, immunization with the C-terminal fragment of ScaA provided neutralizing activity and protective immunity against lethal challenge with O. tsutsugamushi as efficiently as vaccination with the whole passenger domain of ScaA. These results indicate that vMLL5 is a novel cellular receptor for ScaA-mediated adhesion of O. tsutsugamushi and facilitates bacterial adhesion to host cells, thereby enhancing bacterial infection. IMPORTANCE O. tsutsugamushi is a mite-borne pathogen that causes scrub typhus. As an obligately intracellular pathogen, its adhesion to and invasion of host cells are critical steps for bacterial growth. However, the molecular basis of the bacterial ligand and host receptor interaction is poorly defined. Here, we identified a splicing variant of MLL5 (vMLL5) as a cellular adhesion receptor of ScaA, an outer membrane autotransporter protein of O. tsutsugamushi. We mapped the interacting domains in the bacterial ligand and host receptor and confirmed their functional interaction. In addition, immunization with the C-terminal region of ScaA, which involves an interaction with the SET domain of vMLL5, not only induces enhanced neutralizing antibodies but also provides protective immunity against lethal challenge with O. tsutsugamushi.
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18
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Walker DH, Mendell NL. A scrub typhus vaccine presents a challenging unmet need. NPJ Vaccines 2023; 8:11. [PMID: 36759505 PMCID: PMC9910236 DOI: 10.1038/s41541-023-00605-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/17/2023] [Indexed: 02/11/2023] Open
Abstract
Scrub typhus caused by the obligately intracellular bacterium, Orientia tsutsugamushi, is a major cause of life-threatening acute undifferentiated febrile illness in eastern Asia and the islands of the Western Pacific and Indian oceans. Since the estimation of an incidence of 1 million cases annually two decades ago, the number of cases has increased substantially in endemic regions, reappeared where the disease was forgotten, and spread northward. Trombiculid mites are both reservoir and vector. Despite 80 years of efforts to develop a vaccine, there is none. Protective immunity is mediated by antibodies and CD8 and CD4 T cells. Previous efforts have failed because of gaps in understanding immunity to O. tsutsugamushi, particularly the requirements for vaccine-induced immunity, lack of knowledge regarding immune memory in scrub typhus, and lack of attention to addressing the issue of cross-protection between strains. There are numerous strains of O. tsutsugamushi, and modestly durable immunity is strain-specific. Antibodies to the strain that caused infection are protective against challenges with the homologous strain but, despite reactivity with other immunodominant antigens, the immune serum does not protect against heterologous strains. Among the antigens detected by western immunoblot in immune sera (22-, 47-, 56-, 58-, and 110 kDa proteins), only the 56 kDa protein stimulates strong protection. This protein contains four hypervariable regions which are likely, on the basis of limited data, to be the targets of neutralizing antibodies. However, a method that definitively detects neutralizing antibody has yet to be developed. Only one study has used genomic data to pursue the discovery of protective antigens. Three conserved autotransporters were identified, and only immunization with ScaA provided protection against the homologous strain, but only 40% of animals were protected against challenge with a heterologous strain. A multiplex vaccine containing conformational antigens of the hypervariable regions of the 56 kDa protein of the strains of the greatest clinical and epidemiological importance, as well as conserved regions of the 56 kDa protein, ScaA, and other protective antigens identified by future genomic and bioinformatics methods should be developed and tested.
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Affiliation(s)
- David H. Walker
- grid.176731.50000 0001 1547 9964Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
| | - Nicole L. Mendell
- grid.176731.50000 0001 1547 9964Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
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19
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Alkathiry HA, Alghamdi SQ, Morgan HEJ, Noll ME, Khoo JJ, Alagaili AN, Makepeace BL. Molecular Detection of Candidatus Orientia chuto in Wildlife, Saudi Arabia. Emerg Infect Dis 2023; 29:402-406. [PMID: 36692446 PMCID: PMC9881777 DOI: 10.3201/eid2902.221131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Scrub typhus is a zoonosis caused by 3 species of Orientia bacteria, including Candidatus Orientia chuto. This species is known only from a human case in Dubai and infections in wildlife in Kenya. We report molecular detection of Candidatus O. chuto in 2 wild rodent species from Saudi Arabia.
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20
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Faccini-Martínez ÁA, Silva-Ramos CR, Blanton LS, Arroyave E, Martínez-Diaz HC, Betancourt-Ruiz P, Hidalgo M, Walker DH. Serologic Evidence of Orientia Infection among Rural Population, Cauca Department, Colombia. Emerg Infect Dis 2023; 29:456-459. [PMID: 36692499 PMCID: PMC9881757 DOI: 10.3201/eid2902.221458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We assessed serum samples collected in Cauca Department, Colombia, from 486 persons for Orientia seroreactivity. Overall, 13.8% showed reactive IgG by indirect immunofluorescence antibody assay and ELISA. Of those samples, 30% (20/67) were confirmed to be positive by Western blot, showing >1 reactive band to Orientia 56-kD or 47-kD antigens.
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21
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Silva de la Fuente MC, Pérez C, Martínez-Valdebenito C, Pérez R, Vial C, Stekolnikov A, Abarca K, Weitzel T, Acosta-Jamett G. Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile. PLoS Negl Trop Dis 2023; 17:e0011051. [PMID: 36634106 PMCID: PMC9876211 DOI: 10.1371/journal.pntd.0011051] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/25/2023] [Accepted: 12/20/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Scrub typhus is a potentially severe infection caused by bacteria of the genus Orientia, endemic in Asia-Pacific and recently discovered in southern Chile. The presented study aimed to determine the prevalence and species richness of rodent-associated trombiculid mites and their infection with Orientia spp. in different areas of two regions in southern Chile. METHODOLOGY/PRINCIPAL FINDINGS During summer 2020, trombiculid mites were collected from rodents captured in three areas in southern Chile known to be endemic for scrub typhus (Cochamó and Chiloé Island in the Los Lagos Region and Tortel in the Aysén Region). A total of 132 rodents belonging to five species were captured using Sherman-like traps; 89.4% were infested with trombiculids. Mite specimens were morphologically identified and subsequently tested by Orientia-specific qPCR. Six mite species were identified. Among chigger-infested rodents, 33.9% carried Orientia-positive mites; this rate was higher in Tortel (63.8%) than in Cochamó (45.0%) and Chiloé Island (2.0%). The analysis of individual mites (n = 901) revealed that 31.2% of Herpetacarus antarctica samples (n = 202) were positive for Orientia DNA; the prevalence was 7.0% in Paratrombicula neuquenensis (n = 213), 6.9% in Herpetacarus eloisae (n = 144), 3.6% in Argentinacarus expansus (n = 55), and 0% in Paratrombicula goffi (n = 110) and Quadraseta chiloensis (n = 177). The southernmost site (Tortel) showed the highest rates of trombiculid infestation, trombiculid load, and Orientia infection in the captured rodents. CONCLUSIONS/SIGNIFICANCE Our study provides new insights into the trombiculid fauna and prevalence of Orientia in mites collected from wild rodents in southern Chile. Orientia DNA was detected in four of the six mite species. Rates of infestation, mite loads, and Orientia prevalences differed geographically and were highest in the Aysén Region. Our data improve our knowledge on possible vectors of scrub typhus and their distribution in Chile.
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Affiliation(s)
- María Carolina Silva de la Fuente
- Instituto de Medicina Preventiva Veterinaria and Center for Disease Surveillance and Evolution of Infectious Diseases, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Facultad de Ciencias Agrarias y Forestales, Departamento de Ciencias Agrarias, Universidad Católica del Maule, Talca, Chile
| | - Caricia Pérez
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Constanza Martínez-Valdebenito
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Laboratorio de Infectología y Virología Molecular, Red Salud UC–Christus, Santiago, Chile
| | - Ruth Pérez
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Cecilia Vial
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Alexandr Stekolnikov
- Zoological Institute of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Katia Abarca
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Thomas Weitzel
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Gerardo Acosta-Jamett
- Instituto de Medicina Preventiva Veterinaria and Center for Disease Surveillance and Evolution of Infectious Diseases, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- * E-mail:
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22
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Orientia tsutsugamushi Infection in Wild Small Mammals in Western Yunnan Province, China. Pathogens 2023; 12:pathogens12010128. [PMID: 36678476 PMCID: PMC9862787 DOI: 10.3390/pathogens12010128] [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] [Received: 11/14/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/14/2023] Open
Abstract
Small mammals can transmit and serve as a reservoir for Orientia tsutsugamushi (Ot) in nature by carrying infected mites. In Yunnan, one of China's main foci of scrub typhus, etiological evidence and genetic diversity for Ot is limited. A total of 2538 small mammals were captured seasonally from 2015 to 2016 in the three counties of Yunnan, and the spleen or liver tissue was examined for Ot based on 56 kDa nPCR. The overall prevalence of Ot was 1.77%, ranging from 0.26 to 9.09% across different species. The Gilliam strain was found in 35.6% (16/45) of the wild small mammals, followed by the Karp 11.1% (5/45) and TA763 (1/45) strains, the last of which was discovered in western Yunnan for the first time. In Lianghe, Ot infection rates in wild small mammals were higher than in the other two counties. The infection rates of Eothenomys miletus with Ot were highest in the three dominant species. Ot infection rates in wild small mammals were higher in Lianghe (1200-1400 m) and Yulong (2800-3000 m). These findings could provide research clues for further confirmation of scrub typhus foci in western Yunnan or other similar natural environments.
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Genetic recombination of Orientia tsutsugamushi strains from scrub typhus patients in Guangxi, Southwest China, and the analysis of clinical features. Microbes Infect 2023; 25:105098. [PMID: 36621527 DOI: 10.1016/j.micinf.2023.105098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/27/2022] [Accepted: 12/31/2022] [Indexed: 01/07/2023]
Abstract
Three Orientia tsutsugamushi genotypic groups belonging to two prototypes (Gilliam and Karp) were identified in scrub typhus patients from Guangxi, Southwest China. Fever, headache, pneumonia, fatigue, chill, and anorexia were the most common clinical signs. Frequent recombination was observed for their 47-kDa gene compared to 56-kDa and 16S genes. Furthermore, patients infected with the Gilliam prototype represent a much higher proportion of pneumonia (6/6, 100%) than those infected with the Karp prototype (4/8, 50%) (p-value=0.040). This discrepancy is consistent with recent animal tests on rhesus and may indicate different virulence and tissue tropism between different O. tsutsugamushi prototypes.
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Bassini-Silva R, de Castro Jacinavicius F, Muñoz-Leal S, Maturano R, Takatsu JC, Tolesano-Pascoli GV, Alquezar RD, Lugarini C, Ferreira A, Moreira-Lima L, Welbourn C, Ochoa R, Hingst-Zaher E, André MR, Labruna MB, Barros-Battesti DM. Bacterial pathogens' screening in Brazilian chigger mites (Trombidiformes: Trombiculidae), with the first report of 'Candidatus Rickettsia colombianensi'-like in avian-associated chiggers. Arch Microbiol 2023; 205:51. [PMID: 36598595 DOI: 10.1007/s00203-022-03393-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/05/2023]
Abstract
Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a beginning attempt at molecular identification were also provided, as well as, were genetically screened to detect bacterial pathogens. The species B. sinnamaryi and E. tinami were positive for Rickettsia felis-like and 'Candidatus Rickettsia colombianensi'-like, respectively. For the other agents (Anaplasmataceae, Borrelia spp. and Orientia tsutsugamushi), the tests were negative. This is the first report of 'Ca. R. colombianensi'-like and the second record of R. felis-like in chigger collected on birds from Brazil.
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Affiliation(s)
- Ricardo Bassini-Silva
- Laboratório de Coleções Zoológicas, Instituto Butantan, São Paulo, SP, Brazil. .,Departamento de Patologia, Faculdade de Ciências Agrárias e Veterinárias-UNESP, Reprodução e Saúde Única, Jaboticabal, SP, Brazil.
| | | | - Sebastián Muñoz-Leal
- Departamento de Ciencia Animal, Facultad Ciencias Veterinarias, Universidad de Concepción, Ñuble, Chile
| | - Ralph Maturano
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil
| | | | - Graziela Virginia Tolesano-Pascoli
- Laboratório de Ixodologia, Labix, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.,Pós-Graduação em Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Renata D Alquezar
- Pós-Graduação em Ecologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Camile Lugarini
- Centro Nacional de Pesquisa e Conservação de Aves Silvestres (CEMAVE), Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), Cabedelo, PB, Brazil
| | - Ariane Ferreira
- Laboratório de Ornitologia e Bioacústica Catarinense, Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | | | - Cal Welbourn
- Smithsonian Institution, National Museum of Natural History, National Insect and Mite Collection, Washington, DC, USA
| | - Ronald Ochoa
- Systematic Entomology Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | | | - Marcos Rogério André
- Departamento de Patologia, Faculdade de Ciências Agrárias e Veterinárias-UNESP, Reprodução e Saúde Única, Jaboticabal, SP, Brazil
| | - Marcelo Bahia Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia da, Universidade de São Paulo-FMVZ-USP, São Paulo, SP, Brazil
| | - Darci Moraes Barros-Battesti
- Departamento de Patologia, Faculdade de Ciências Agrárias e Veterinárias-UNESP, Reprodução e Saúde Única, Jaboticabal, SP, Brazil
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Parai D, Pattnaik M, Kshatri JS, Rout UK, Peter A, Nanda RR, Sahoo SK, Mansingh A, Choudhary HR, Dash GC, Praharaj I, Bhattacharya D, Pati S. Scrub typhus seroprevalence from an eastern state of India: findings from the state-wide serosurvey. Trans R Soc Trop Med Hyg 2023; 117:22-27. [PMID: 35947959 DOI: 10.1093/trstmh/trac075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/30/2022] [Accepted: 07/29/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Scrub typhus is a mite-borne infectious disease caused primarily by the obligate intracellular bacteria Orientia tsutsugamushi, which is transmitted by chigger mites. The objective of this study was to determine the prevalence of scrub typhus among adults in Odisha, an eastern state of India. METHODS A descriptive cross-sectional study was conducted to analyse 1840 serum samples from five districts (Khordha, Cuttack, Ganjam, Malkangiri and Sundargarh) of Odisha collected during 2020-2021. Both immunoglobulin G (IgG) and IgM antibodies against scrub typhus were tested using commercial enzyme-linked immunosorbent assay kits. Point estimates of the 95% confidence interval and adjusted odds ratio were calculated. RESULTS Of 1840 participants, the prevalence of IgG positivity was 1034 (56.19%) and that of IgM was 523 (28.42%). The majority of participants were in the 18-45 y age group (53.7%). Cuttack had the highest IgG positivity (64.54%) and Malkangiri had the lowest (29.32%). The highest and lowest positivity for IgM were found in Malkangiri (40.84%) and Cuttack (25.30%), respectively. CONCLUSIONS With an increasing number of infections detected in the state, scrub typhus is emerging as a public health threat. Increasing awareness among the general public and healthcare professionals through health education campaigns regarding scrub typhus is essential. Early detection of the disease through the establishment of a laboratory surveillance system is required to control the transmission of scrub typhus.
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Affiliation(s)
- Debaprasad Parai
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Matrujyoti Pattnaik
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Jaya Singh Kshatri
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Usha Kiran Rout
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Annalisha Peter
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Rashmi Ranjan Nanda
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Subrat Kumar Sahoo
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Asit Mansingh
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Hari Ram Choudhary
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Girish Chandra Dash
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Ira Praharaj
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Debdutta Bhattacharya
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
| | - Sanghamitra Pati
- Department of Microbiology, Indian Council of Medical Research-Regional Medical Research Centre, Chandrasekharpur, Bhubaneswar 751023, India
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Moniuszko H, Wojnarowski K, Cholewińska P. Not Only Leptotrombidium spp. an Annotated Checklist of Chigger Mites (Actinotrichida: Trombiculidae) Associated with Bacterial Pathogens. Pathogens 2022; 11:pathogens11101084. [PMID: 36297141 PMCID: PMC9611227 DOI: 10.3390/pathogens11101084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/19/2022] [Accepted: 09/20/2022] [Indexed: 12/02/2022] Open
Abstract
Mites of the family Trombiculidae are known for playing a role in maintaining and spreading the scrub typhus etiologic agent, an intracellular Gram-negative bacterium, Orientia tsutsugamushi. Species of the genus Leptotrombidium are investigated most thoroughly, particularly in SE Asia, and a few are proven vectors for the pathogen. The mentioned association, however, is not the only one among trombiculids. Here, we present a list of chiggers indicated in the literature as positive for bacterial pathogens, tested throughout almost 100 years of research. Taxonomic identities of trombiculids follow recent revisions and checklists. Results point at 100 species, from 28 genera, evidenced for association with 31 bacterial taxa. Pathogen-positive mites constitute around 3.3% of the total number of species comprising the family. Discussed arachnids inhabit six biogeographic realms and represent free-living instars as well as external and internal parasites of rodents, soricomorphs, scadents, lagomorphs, peramelemorphs, bats, passerine birds, reptiles and humans. A variety of so far detected bacteria, including novel species, along with the mites’ vast geographical distribution and parasitism on differentiated hosts, indicate that revealing of more cases of Trombiculidae-pathogens association is highly probable, especially utilizing the newest techniques enabling a large-scale bacterial communities survey.
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Affiliation(s)
- Hanna Moniuszko
- Section of Basic Research in Horticulture, Department of Plant Protection, Institute of Horticultural Sciences, Warsaw University of Life Sciences—SGGW, 02-776 Warsaw, Poland
- Correspondence:
| | - Konrad Wojnarowski
- Chair for Fish Diseases and Fisheries Biology, Ludwig-Maximilians-University of Munich, 80539 Munich, Germany
| | - Paulina Cholewińska
- Institute of Animal Breeding, Wroclaw University of Environmental and Life Sciences, 51-630 Wroclaw, Poland
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Herrera-Mares A, Guzmán-Cornejo C, Ulloa-García A, Córdoba-Aguilar A, Silva-de la Fuente MC, Suzán G. Mites, rodents, and pathogens: A global review for a multi-species interaction in disease ecology. Acta Trop 2022; 232:106509. [PMID: 35569525 DOI: 10.1016/j.actatropica.2022.106509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 11/15/2022]
Abstract
More than ever, there is a need to understand how pathogens, vectors and hosts occur temporally and spatially to predict the occurrence of zoonotic outbreaks. Related to this, mites of the Mesostigmata and Trombidiformes orders have the potential to transmit several diseases, yet their information of occurrence, distribution and zoonotic accompanying agents have not been systematically organized. We conducted a systematic review using a combination of words through the Sysrev platform, as well as literature searches in specialised databases to identify global patterns of infections, trends in mite-rodent-pathogen research and existing knowledge gaps. The inclusion criterion was the detection of pathogens in mites, either by molecular or serological techniques or by direct observation under the microscope, which rendered 125 papers. Most works have been carried out in Asia, mainly around the transmission of Orientia tsutsugamushi. Interestingly, co-infections, i.e., the presence of more than one pathogen in an individual, are common in other Acari groups such as ticks. Moreover, this is not the case for Trombidiformes and Mesostigmata as only 4.7 percent of the articles reviewed detected more than one pathogen in these mites. It is important to include a multi-host, multi-vector and multi-pathogen approaches to understand complex systems in disease ecology. A synergy between mite taxonomists, physicians and veterinarians, decision-makers, governmental organisations, and society is needed to address the emergence of mite-borne new or neglected diseases.
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Affiliation(s)
- Angel Herrera-Mares
- Departamento de Etología, Laboratorio de Ecología de Enfermedades y Una Salud, Fauna Silvestre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico; Posgrado en Ciencias Biológicas, Unidad de Posgrado, Universidad Nacional Autónoma de México, Mexico
| | - Carmen Guzmán-Cornejo
- Departamento de Biología Comparada, Facultad de Ciencias, Laboratorio de Acarología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Armando Ulloa-García
- Facultad de Ciencias Químicas, Campus IV, Universidad Autónoma de Chiapas, Tapachula, Chiapas, Mexico
| | - Alex Córdoba-Aguilar
- Instituto de Ecología, Universidad, Nacional Autónoma de México, Mexico City, Mexico
| | | | - Gerardo Suzán
- Departamento de Etología, Laboratorio de Ecología de Enfermedades y Una Salud, Fauna Silvestre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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Ponnusamy L, Garshong R, McLean BS, Wasserberg G, Durden LA, Crossley D, Apperson CS, Roe RM. Rickettsia felis and Other Rickettsia Species in Chigger Mites Collected from Wild Rodents in North Carolina, USA. Microorganisms 2022; 10:microorganisms10071342. [PMID: 35889061 PMCID: PMC9324336 DOI: 10.3390/microorganisms10071342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 02/04/2023] Open
Abstract
Chiggers are vectors of rickettsial pathogenic bacteria, Orientia spp., that cause the human disease, scrub typhus, in the Asian–Pacific area and northern Australia (known as the Tsutsugamushi Triangle). More recently, reports of scrub typhus in Africa, southern Chile, and the Middle East have reshaped our understanding of the epidemiology of this disease, indicating it has a broad geographical distribution. Despite the growing number of studies and discoveries of chigger-borne human disease outside of the Tsutsugamushi Triangle, rickettsial pathogens in chigger mites in the US are still undetermined. The aim of our study was to investigate possible Rickettsia DNA in chiggers collected from rodents in North Carolina, USA. Of 46 chiggers tested, 47.8% tested positive for amplicons of the 23S-5S gene, 36.9% tested positive for 17 kDa, and 15.2% tested positive for gltA. Nucleotide sequence analyses of the Rickettsia-specific 23S-5S intergenic spacer (IGS), 17 kDa, and gltA gene fragments indicated that the amplicons from these chiggers were closely related to those in R. felis, R. conorii, R. typhi, and unidentified Rickettsia species. In this study, we provide the first evidence of Rickettsia infection in chiggers collected from rodents within the continental USA. In North Carolina, a US state with the highest annual cases of spotted fever rickettsioses, these results suggest chigger bites could pose a risk to public health, warranting further study.
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Affiliation(s)
- Loganathan Ponnusamy
- Department of Entomology and Plant Pathology, Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695, USA; (C.S.A.); (R.M.R.)
- Correspondence:
| | - Reuben Garshong
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27402, USA; (R.G.); (B.S.M.); (G.W.)
| | - Bryan S. McLean
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27402, USA; (R.G.); (B.S.M.); (G.W.)
| | - Gideon Wasserberg
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27402, USA; (R.G.); (B.S.M.); (G.W.)
| | - Lance A. Durden
- Department of Biology, Georgia Southern University, 4324 Old Register Road Statesboro, Statesboro, GA 30458, USA;
| | - Dac Crossley
- Georgia Museum of Natural History, Natural History Building, University of Georgia, Athens, GA 30602, USA;
| | - Charles S. Apperson
- Department of Entomology and Plant Pathology, Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695, USA; (C.S.A.); (R.M.R.)
| | - R. Michael Roe
- Department of Entomology and Plant Pathology, Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27695, USA; (C.S.A.); (R.M.R.)
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Jiang J, Martínez-Valdebenito C, Weitzel T, Farris CM, Acosta-Jamett G, Abarca K, Richards AL. Development of a New Genus-Specific Quantitative Real-Time PCR Assay for the Diagnosis of Scrub Typhus in South America. Front Med (Lausanne) 2022; 9:831045. [PMID: 35573006 PMCID: PMC9095740 DOI: 10.3389/fmed.2022.831045] [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: 12/07/2021] [Accepted: 04/05/2022] [Indexed: 12/02/2022] Open
Abstract
Scrub typhus is a potentially severe rickettsiosis, caused by Orientia tsutsugamushi in the Asia-Pacific region. Recently, however, two distinct pathogens, “Candidatus Orientia chuto” and “Candidatus Orientia chiloensis”, have been discovered in the Middle East and South America, respectively. Since the novel pathogens differ significantly from O. tsutsugamushi, many established diagnostic methods are unreliable. This work describes the development and validation of a new quantitative real-time PCR (qPCR) assay (Orien16S) for the detection of all known Orientia species. Based on a 94 bp sequence of the 16S rRNA gene (rrs), Orien16S recognized DNA samples from O. tsutsugamushi (n = 41), Ca. O. chiloensis (n = 5), and Ca. O. chuto (n = 1), but was negative for DNA preparations from closely related rickettsiae and other members of the order Rickettsiales (n = 22) as well as unrelated bacterial species (n = 11). After its implementation in Chile, the assay was verified, correctly identifying all tested eschar and buffy coat samples (n = 28) of clinical suspected cases. Furthermore, Orien16S detected Orientia DNA in trombiculid mites collected in endemic regions in southern Chile. The presented novel qPCR assay provides a useful tool for detecting Orientia and diagnosing scrub typhus from all geographical regions.
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Affiliation(s)
- Ju Jiang
- Naval Medical Research Center, Silver Spring, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Constanza Martínez-Valdebenito
- Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.,Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | | | - Gerardo Acosta-Jamett
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.,Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Katia Abarca
- Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Allen L Richards
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States.,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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30
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Functional Characterization of Non-Ankyrin Repeat Domains of Orientia tsutsugamushi Ank Effectors Reveals Their Importance for Molecular Pathogenesis. Infect Immun 2022; 90:e0062821. [PMID: 35435726 DOI: 10.1128/iai.00628-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Orientia tsutsugamushi is a genetically intractable obligate intracellular bacterium, causes scrub typhus, and has one of the largest known armamentariums of ankyrin repeat-containing effectors (Anks). Most have a C-terminal F-box presumed to interact with the SCF ubiquitin ligase complex primarily based on their ability to bind overexpressed Skp1. Whether all F-box-containing Anks bind endogenous SCF components and the F-box residues essential for such interactions has gone unexplored. Many O. tsutsugamushi Ank F-boxes occur as part of a PRANC (pox protein repeats of ankyrin-C-terminal) domain. Roles of the non-F-box portion of the PRANC and intervening sequence region (ISR) that links the ankyrin repeat and F-box/PRANC domains are unknown. The functional relevance of these effectors' non-ankyrin repeat domains was investigated. The F-box was necessary for Flag-tagged versions of most F-box-containing Anks to precipitate endogenous Skp1, Cul1, and/or Rbx1, while the ISR and PRANC were dispensable. Ank toxicity in yeast was predominantly F-box dependent. Interrogations of Ank1, Ank5, and Ank6 established that L1, P2, E4, I9, and D17 of the F-box consensus are key for binding native SCF components and for Ank1 and Ank6 to inhibit NF-κB. The ISR is also essential for Ank1 and Ank6 to impair NF-κB. Ectopically expressed Ank1 and Ank6 lacking the ISR or having a mutagenized F-box incapable of binding SCF components performed as dominant-negative inhibitors to block O. tsutsugamushi NF-κB modulation. This study advances knowledge of O. tsutsugamushi Ank functional domains and offers an approach for validating their roles in infection.
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Chaisiri K, Tanganuchitcharnchai A, Kritiyakan A, Thinphovong C, Tanita M, Morand S, Blacksell SD. Risk factors analysis for neglected human rickettsioses in rural communities in Nan province, Thailand: A community-based observational study along a landscape gradient. PLoS Negl Trop Dis 2022; 16:e0010256. [PMID: 35320277 PMCID: PMC8979453 DOI: 10.1371/journal.pntd.0010256] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 04/04/2022] [Accepted: 02/12/2022] [Indexed: 12/05/2022] Open
Abstract
In this study, we estimated exposure for Scrub typhus (STG), Typhus (TG) and Spotted fever groups (SFG) rickettsia using serology at a fine scale (a whole sub-district administration level) of local communities in Nan Province, Thailand. Geographical characteristics of the sub-district were divided into two landscape types: lowland agricultural area in an urbanized setting (lowland-urbanized area) and upland agricultural area located close to a protected area of National Park (upland-forested area). This provided an ideal contrast between the two landscapes with low and high levels of human-altered habitats to study in differences in disease ecology. In total, 824 serum samples of participants residing in the eight villages were tested by screening IgG ELISA, and subsequently confirmed by the gold standard IgG Immunofluorescent Assay (IFA). STG and TG IgG positivity were highest with seroprevalence of 9.8% and 9.0%, respectively; whereas SFG positivity was lower at 6.9%. Inhabitants from the villages located in upland-forested area demonstrated significantly higher STG exposure, compared to those villages in the lowland-urbanized area (chi-square = 51.97, p < 0.0001). In contrast, TG exposure was significantly higher in those villagers living in lowland-urbanized area (chi-square = 28.26, p < 0.0001). In addition to the effect of landscape types, generalized linear model (GLM) analysis identified socio-demographic parameters, i.e., gender, occupation, age, educational level, domestic animal ownership (dog, cattle and poultry) as influential factors to explain the level of rickettsial exposure (antibody titers) in the communities. Our findings raise the public health awareness of rickettsiosis as a cause of undiagnosed febrile illness in the communities. Evidence of human exposures to rickettsial pathogens were reported from a cross-sectional study at a whole sub-district scale of local communities in Nan Province, Thailand. Seroprevalence and level of rickettsial exposures demonstrated differences between the habitat types, ecological aspects and socio-demographic factors. In addition, abundance of domestic animals in the community appeared to be one of significant factors influencing levels of human exposure to rickettsial pathogens. Our findings will benefit the local public health by raising awareness of rickettsial infections as one of potential health concerns in the community. Inclusion of rickettsioses in routine laboratory diagnosis would help to differentiate unknown febrile illness and guide appropriate treatment. Further studies are required, particularly in the fields of disease ecology as well as medical and veterinary entomology, in order to better understand epidemiology and potential zoonotic transmission of these neglected rickettsioses in endemic areas.
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Affiliation(s)
- Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- * E-mail: (KC); (SDB)
| | - Ampai Tanganuchitcharnchai
- Mahidol-Oxford Tropical Research Medicine Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Anamika Kritiyakan
- Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | | | - Malee Tanita
- Saen Thong Health Promoting Hospital, Tha Wang Pha, Nan, Thailand
| | - Serge Morand
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
- Faculty of Veterinary Technology, CNRS ISEM–CIRAD ASTRE, Kasetsart University, Bangkok, Thailand
| | - Stuart D. Blacksell
- Mahidol-Oxford Tropical Research Medicine Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Center for Tropical Medicine & Global Health, Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
- * E-mail: (KC); (SDB)
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Di Cataldo S, Cevidanes A, Ulloa-Contreras C, Hidalgo-Hermoso E, Gargano V, Cabello J, Sacristán I, Napolitano C, Gambino D, Vicari D, Millán J. A serosurvey for spotted fever group Rickettsia and Coxiella burnetii antibodies in rural dogs and foxes, Chile. Comp Immunol Microbiol Infect Dis 2022; 83:101769. [DOI: 10.1016/j.cimid.2022.101769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 11/30/2022]
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Oren A, Garrity GM. CANDIDATUS LIST No. 3. Lists of names of prokaryotic Candidatus taxa. Int J Syst Evol Microbiol 2022; 72. [PMID: 35100104 DOI: 10.1099/ijsem.0.005186] [Citation(s) in RCA: 251] [Impact Index Per Article: 125.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Aharon Oren
- The Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, 9190401 Jerusalem, Israel
| | - George M Garrity
- Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences, Michigan State University, East Lansing, MI 48824-4320, USA
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Wulandhari SA, Paladsing Y, Saesim W, Charoennitiwat V, Sonthayanon P, Kumlert R, Morand S, Sumruayphol S, Chaisiri K. High prevalence and low diversity of chigger infestation in small mammals found in Bangkok Metropolitan parks. MEDICAL AND VETERINARY ENTOMOLOGY 2021; 35:534-546. [PMID: 34021500 DOI: 10.1111/mve.12531] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/03/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
Chiggers are recognized as vectors of scrub typhus disease caused by the bacteria, Orientia tsutsugamushi. The risk of disease exposure is mainly related to chigger bites when humans or animals roam into vector-infested habitats. In big cities, urban public parks could provide areas for the animal-human interface and zoonotic pathogen transmission. The ecology and epidemiology of urban scrub typhus are still poorly understood in Thailand. Small mammals were trapped and examined for chigger infestation in urban public parks across metropolitan Bangkok, Thailand. We found a high prevalence of infestation (76.8%) with surprisingly low diversity. Two chigger species, Leptotrombidium deliense and Ascoschoengastia indica, were identified using morphological characteristics and molecular confirmation. The generalized linear model identified host intrinsic variables (i.e. body mass index) with host density, habitat composition and open field as the extrinsic factors explaining the abundance of chigger infestation. The bacteria O. tsutsugamushi was not detected in chiggers (90 chigger-pooled samples) and animal host tissues (164 spleen samples). However, the existence of chigger vectors calls for the Bangkok Metropolitan Administration and public health authorities to develop a comprehensive scrub typhus monitoring and prevention strategy in the parks and nearby communities.
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Affiliation(s)
- S A Wulandhari
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Y Paladsing
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - W Saesim
- Environment Department, Bangkok Metropolitan Administration, Bangkok, Thailand
| | - V Charoennitiwat
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - P Sonthayanon
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - R Kumlert
- Division of Vector-Borne Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - S Morand
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- CNRS-CIRAD, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | - S Sumruayphol
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - K Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Saraswati K, Maguire BJ, McLean ARD, Singh-Phulgenda S, Ngu RC, Newton PN, Day NPJ, Guérin PJ. Systematic review of the scrub typhus treatment landscape: Assessing the feasibility of an individual participant-level data (IPD) platform. PLoS Negl Trop Dis 2021; 15:e0009858. [PMID: 34648517 PMCID: PMC8547739 DOI: 10.1371/journal.pntd.0009858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 10/26/2021] [Accepted: 09/28/2021] [Indexed: 01/18/2023] Open
Abstract
Background Scrub typhus is an acute febrile illness caused by intracellular bacteria from the genus Orientia. It is estimated that one billion people are at risk, with one million cases annually mainly affecting rural areas in Asia-Oceania. Relative to its burden, scrub typhus is understudied, and treatment recommendations vary with poor evidence base. These knowledge gaps could be addressed by establishing an individual participant-level data (IPD) platform, which would enable pooled, more detailed and statistically powered analyses to be conducted. This study aims to assess the characteristics of scrub typhus treatment studies and explore the feasibility and potential value of developing a scrub typhus IPD platform to address unanswered research questions. Methodology/principal findings We conducted a systematic literature review looking for prospective scrub typhus clinical treatment studies published from 1998 to 2020. Six electronic databases (Ovid Embase, Ovid Medline, Ovid Global Health, Cochrane Library, Scopus, Global Index Medicus), ClinicalTrials.gov, and WHO ICTRP were searched. We extracted data on study design, treatment tested, patient characteristics, diagnostic methods, geographical location, outcome measures, and statistical methodology. Among 3,100 articles screened, 127 were included in the analysis. 12,079 participants from 12 countries were enrolled in the identified studies. ELISA, PCR, and eschar presence were the most commonly used diagnostic methods. Doxycycline, azithromycin, and chloramphenicol were the most commonly administered antibiotics. Mortality, complications, adverse events, and clinical response were assessed in most studies. There was substantial heterogeneity in the diagnostic methods used, treatment administered (including dosing and duration), and outcome assessed across studies. There were few interventional studies and limited data collected on specific groups such as children and pregnant women. Conclusions/significance There were a limited number of interventional trials, highlighting that scrub typhus remains a neglected disease. The heterogeneous nature of the available data reflects the absence of consensus in treatment and research methodologies and poses a significant barrier to aggregating information across available published data without access to the underlying IPD. There is likely to be a substantial amount of data available to address knowledge gaps. Therefore, there is value for an IPD platform that will facilitate pooling and harmonisation of currently scattered data and enable in-depth investigation of priority research questions that can, ultimately, inform clinical practice and improve health outcomes for scrub typhus patients. Scrub typhus is a febrile illness most commonly found in rural tropical areas. It is caused by a Gram-negative bacteria belonging to the family Rickettsiaceae and transmitted by mites when they feed on vertebrates. There is an estimate of one million cases annually, with an estimated one billion people at risk, mostly in Asia-Oceania. But relative to the scale of the problem, scrub typhus is largely understudied. Evidence-based treatment recommendations by policymakers vary or are non-existent. We searched databases and registries for prospective scrub typhus clinical treatment studies published from 1998 to 2020 and reviewed them. Data from clinical trials and particularly for specific groups, such as pregnant women and children, were minimal. The methods used to measure treatment efficacy were heterogeneous, making it difficult to directly compare or conduct a meta-analysis based on aggregated data. One way to improve the current level of evidence would be by pooling and analysing individual participant-level data (IPD), i.e. the raw data from individual participants in completed studies. This review demonstrated that there is scope for developing a database for individual participant data to enable more detailed analyses. IPD meta-analyses could be a way to address knowledge gaps such as optimum dosing for children and pregnant women.
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Affiliation(s)
- Kartika Saraswati
- Eijkman-Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jakarta, Indonesia
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail: (KS); (PJG)
| | - Brittany J. Maguire
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Alistair R. D. McLean
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sauman Singh-Phulgenda
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Roland C. Ngu
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paul N. Newton
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People’s Democratic Republic
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Philippe J. Guérin
- Infectious Diseases Data Observatory (IDDO), Oxford, United Kingdom
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail: (KS); (PJG)
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Hunt JR, Carlyon JA. Analysis of Orientia tsutsugamushi promoter activity. Pathog Dis 2021; 79:6369350. [PMID: 34515306 DOI: 10.1093/femspd/ftab044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/10/2021] [Indexed: 02/07/2023] Open
Abstract
Orientia tsutsugamushi is an obligate intracellular bacterium that causes scrub typhus, a potentially fatal rickettsiosis, and for which no genetic tools exist. Critical to addressing this technical gap is to identify promoters for driving expression of antibiotic resistance and fluorescence reporter genes in O. tsutsugamushi. Such promoters would need to be highly conserved among strains, expressed throughout infection, and exhibit strong activity. We examined the untranslated regions upstream of O. tsutsugamushi genes encoding outer membrane protein A (ompA), 22-kDa type-specific antigen (tsa22) and tsa56. The bacterium transcribed all three during infection of monocytic, endothelial and epithelial cells. Examination of the upstream noncoding regions revealed putative ribosome binding sites, one set of predicted -10 and -35 sequences for ompA and two sets of -10 and -35 sequences for tsa22 and tsa56. Comparison of these regions among geographically diverse O. tsutsugamushi patient isolates revealed nucleotide identities ranging from 84.8 to 100.0%. Upon examination of the candidates for the ability to drive green fluorescence protein expression in Escherichia coli, varying activities were observed with one of the tsa22 promoters being the strongest. Identification and validation of O. tsutsugamushi promoters is an initial key step toward genetically manipulating this important pathogen.
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Affiliation(s)
- Jason R Hunt
- Department of Microbiology and Immunology, Virginia Commonwealth University (VCU) Medical Center, School of Medicine, VCU, Richmond, VA 23298, USA
| | - Jason A Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University (VCU) Medical Center, School of Medicine, VCU, Richmond, VA 23298, USA
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Wilairatana P, Kuraeiad S, Rattaprasert P, Kotepui M. Prevalence of malaria and scrub typhus co-infection in febrile patients: a systematic review and meta-analysis. Parasit Vectors 2021; 14:471. [PMID: 34521454 PMCID: PMC8442375 DOI: 10.1186/s13071-021-04969-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Little information is available about malaria and scrub typhus co-infection. This study aimed to investigate the pooled prevalence of malaria and scrub typhus co-infection in febrile patients. Further, it aimed to estimate the prevalence of scrub typhus infection among patients with malaria and the odds of co-infection. This will aid the diagnosis and management of co-infected patients in endemic areas. METHODS We searched for relevant studies in three databases: PubMed, Scopus, and Web of Science. We assessed the quality of the included studies using the Joanna Briggs Institute checklist for analytical cross-sectional studies. We estimated (1) the pooled prevalence of malaria and scrub typhus co-infection, (2) the pooled prevalence of scrub typhus infection in malaria-positive patients, and (3) the pooled odds of co-infection using the DerSimonian-Laird method for random-effects models. The study results and summary estimates were visualized on a forest plot as point estimates (effect size, prevalence) and 95% confidence intervals (CI). We assessed the heterogeneity of the studies by Cochrane Q or I2 statistics. We performed subgroup analyses of countries and scrub typhus diagnostic tests to explore the sources of heterogeneity of the included studies. We assessed publication bias if more than 10 studies were used to estimate the outcome. All data analyses were conducted using Stata version 14 (StataCorp, College Station, TX, USA). RESULTS Of the 542 studies retrieved from three databases, we included 14 meeting the inclusion criteria in the systematic review and meta-analysis. The pooled prevalence of malaria and scrub typhus co-infection (56 cases) among febrile patients (7920 cases) was 1% (95% CI: 0-1%, I2: 78.28%), while the pooled prevalence of scrub typhus infection (321 cases) in patients with malaria (1418 cases) was 21% (95% CI: 12-30%, I2: 98.15%). Subgroup analysis showed that the pooled prevalence of scrub typhus infection among patients with malaria in India was 8% (95% CI: 4-13%, I2: 85.87%, nine studies with 59/794 cases), while the pooled prevalence of scrub typhus infection among patients with malaria in Thailand was 35% (95% CI: 7-64%, I2: 98.9%, four studies with 262/624 cases). The co-infections did not occur by chance (P = 0.013, odds: 0.43, 95% CI: 0.22-0.84%, I2: 60.9%). In the sensitivity analysis, the pooled prevalence of malaria and scrub typhus co-infection among febrile patients was 0% (95% CI: 0-1%, I2: 59.91%). CONCLUSIONS The present study showed the pooled prevalence and a significant association between malaria and scrub typhus. The results show the status of co-infection. Further research into co-infection in endemic areas is needed, in particular, to determine whether co-infection can accelerate disease progression or protect against severe disease.
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Affiliation(s)
- Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Saruda Kuraeiad
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, 80160, Thailand
| | - Pongruj Rattaprasert
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Manas Kotepui
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, 80160, Thailand.
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Weitzel T, Silva-de la Fuente MC, Martínez-Valdebenito C, Stekolnikov AA, Pérez C, Pérez R, Vial C, Abarca K, Acosta-Jamett G. Novel vector of scrub typhus in subantarctic Chile - evidence from human exposure. Clin Infect Dis 2021; 74:1862-1865. [PMID: 34453514 DOI: 10.1093/cid/ciab748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Indexed: 11/15/2022] Open
Abstract
The exposure of a research team to chigger mites in southern Chile allowed the first identification of a trombiculid species as vector and reservoir of scrub typhus outside the tsutsugamushi triangle, providing unique insights into the ecology and transmission of this recently discovered rickettsial infection in South America.
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Affiliation(s)
- Thomas Weitzel
- Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.,Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | | | | | | | - Caricia Pérez
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Ruth Pérez
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Cecilia Vial
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Katia Abarca
- Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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Linsuwanon P, Wongwairot S, Auysawasdi N, Monkanna T, Richards AL, Leepitakrat S, Sunyakumthorn P, Im-Erbsin R, Poole-Smith K, McCardle P. Establishment of a Rhesus Macaque Model for Scrub Typhus Transmission: Pilot Study to Evaluate the Minimal Orientia tsutsugamushi Transmission Time by Leptotrombidium chiangraiensis Chiggers. Pathogens 2021; 10:pathogens10081028. [PMID: 34451491 PMCID: PMC8402083 DOI: 10.3390/pathogens10081028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/02/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Recently, an intradermal inoculation of the rhesus macaque model of scrub typhus has been characterized at our institution. The current project was to establish a rhesus macaque model of scrub typhus using the naturally infected chigger challenge method that faithfully mimics the natural route of pathogen transmission to fully understand the host-pathogen-vector interactions influencing pathogen transmission. Unlike the needle-based inoculation route, Orientia tsutsugamushi-infected chiggers introduce both pathogen and chigger saliva into the host epidermis at the bite site. However, information on the interaction or influence of chigger saliva on pathogenesis and immunity of host has been limited, consequently hindering vaccine development and transmission-blocking studies. To characterize chigger inoculated O. tsutsugamushi in rhesus macaques, we determined the minimum chigger attachment time required to efficiently transmit O. tsutsugamushi to the immunocompetent hosts and preliminary assessed clinical parameters, course of bacterial infection, and host’s immunological response to identifying potential factors influencing pathogen infection. Chigger infestation on hosts resulted in: (i) Rapid transmission of O. tsutsugamushi within 1 h and (ii) antigen-specific type I and II T-cell responses were markedly increased during the acute phase of infection, suggesting that both systems play critical roles in response to the pathogen control during the primary infection. In summary, we demonstrate that O. tsutsugamushi infection in rhesus macaques via chigger challenge recapitulates the time of disease onset and bacteremia observed in scrub typhus patients. Levels of proinflammatory cytokines and chemokines were positively correlated with bacteremia.
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Affiliation(s)
- Piyada Linsuwanon
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
- Correspondence:
| | - Sirima Wongwairot
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
| | - Nutthanun Auysawasdi
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
| | - Taweesak Monkanna
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
| | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of Health Sciences, Bethesda, MD 20814, USA;
| | - Surachai Leepitakrat
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
| | - Piyanate Sunyakumthorn
- Department of Veterinary Medicine, USAMD-AFRIMS, Bangkok 10330, Thailand; (P.S.); (R.I.-E.)
| | - Rawiwan Im-Erbsin
- Department of Veterinary Medicine, USAMD-AFRIMS, Bangkok 10330, Thailand; (P.S.); (R.I.-E.)
| | - Katie Poole-Smith
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
| | - Patrick McCardle
- Department of Entomology, USAMD-AFRIMS, Bangkok 10330, Thailand; (S.W.); (N.A.); (T.M.); (S.L.); (K.P.-S.); (P.M.)
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Vaccine Design and Vaccination Strategies against Rickettsiae. Vaccines (Basel) 2021; 9:vaccines9080896. [PMID: 34452021 PMCID: PMC8402588 DOI: 10.3390/vaccines9080896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 12/30/2022] Open
Abstract
Rickettsioses are febrile, potentially lethal infectious diseases that are a serious health threat, especially in poor income countries. The causative agents are small obligate intracellular bacteria, rickettsiae. Rickettsial infections are emerging worldwide with increasing incidence and geographic distribution. Nonetheless, these infections are clearly underdiagnosed because methods of diagnosis are still limited and often not available. Another problem is that the bacteria respond to only a few antibiotics, so delayed or wrong antibiotic treatment often leads to a more severe outcome of the disease. In addition to that, the development of antibiotic resistance is a serious threat because alternative antibiotics are missing. For these reasons, prophylactic vaccines against rickettsiae are urgently needed. In the past years, knowledge about protective immunity against rickettsiae and immunogenic determinants has been increasing and provides a basis for vaccine development against these bacterial pathogens. This review provides an overview of experimental vaccination approaches against rickettsial infections and perspectives on vaccination strategies.
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Orientia tsutsugamushi Nucleomodulin Ank13 Exploits the RaDAR Nuclear Import Pathway To Modulate Host Cell Transcription. mBio 2021; 12:e0181621. [PMID: 34340535 PMCID: PMC8406279 DOI: 10.1128/mbio.01816-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Orientia tsutsugamushi is the etiologic agent of scrub typhus, the deadliest of all diseases caused by obligate intracellular bacteria. Nucleomodulins, bacterial effectors that dysregulate eukaryotic transcription, are being increasingly recognized as key virulence factors. How they translocate into the nucleus and their functionally essential domains are poorly defined. We demonstrate that Ank13, an O. tsutsugamushi effector conserved among clinical isolates and expressed during infection, localizes to the nucleus in an importin β1-independent manner. Rather, Ank13 nucleotropism requires an isoleucine at the thirteenth position of its fourth ankyrin repeat, consistent with utilization of eukaryotic RaDAR (RanGDP-ankyrin repeats) nuclear import. RNA-seq analyses of cells expressing green fluorescent protein (GFP)-tagged Ank13, nucleotropism-deficient Ank13I127R, or Ank13ΔF-box, which lacks the F-box domain essential for interacting with SCF ubiquitin ligase, revealed Ank13 to be a nucleomodulin that predominantly downregulates transcription of more than 2,000 genes. Its ability to do so involves its nucleotropism and F-box in synergistic and mutually exclusive manners. Ank13 also acts in the cytoplasm to dysregulate smaller cohorts of genes. The effector’s toxicity in yeast heavily depends on its F-box and less so on its nucleotropism. Genes negatively regulated by Ank13 include those involved in the inflammatory response, transcriptional control, and epigenetics. Importantly, the majority of genes that GFP-Ank13 most strongly downregulates are quiescent or repressed in O. tsutsugamushi-infected cells when Ank13 expression is strongest. Ank13 is the first nucleomodulin identified to coopt RaDAR and a multifaceted effector that functions in the nucleus and cytoplasm via F-box-dependent and -independent mechanisms to globally reprogram host cell transcription.
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Silva-Ramos CR, Jacinavicius FDC, Weitzel T, Walker DH, Faccini-Martínez ÁA. Scrub typhus: A new cause of acute undifferentiated febrile illness in Latin America? Travel Med Infect Dis 2021; 43:102138. [PMID: 34260988 DOI: 10.1016/j.tmaid.2021.102138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 07/07/2021] [Indexed: 01/31/2023]
Affiliation(s)
- Carlos Ramiro Silva-Ramos
- Grupo de Enfermedades Infecciosas, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | | | - Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad Del Desarrollo, Santiago, Chile; Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad Del Desarrollo, Santiago, Chile.
| | - David H Walker
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Álvaro A Faccini-Martínez
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA; Committee of Tropical Medicine, Zoonoses and Travel Medicine, Asociación Colombiana de Infectología, Bogotá, Colombia.
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Comparison of Lethal and Nonlethal Mouse Models of Orientia tsutsugamushi Infection Reveals T-Cell Population-Associated Cytokine Signatures Correlated with Lethality and Protection. Trop Med Infect Dis 2021; 6:tropicalmed6030121. [PMID: 34287349 PMCID: PMC8293330 DOI: 10.3390/tropicalmed6030121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/25/2021] [Accepted: 06/30/2021] [Indexed: 11/19/2022] Open
Abstract
The antigenic diversity of Orientia tsutsugamushi as well as the interstrain difference(s) associated with virulence in mice impose the necessity to dissect the host immune response. In this study we compared the host response in lethal and non-lethal murine models of O. tsutsugamushi infection using the two strains, Karp (New Guinea) and Woods (Australia). The models included the lethal model: Karp intraperitoneal (IP) challenge; and the nonlethal models: Karp intradermal (ID), Woods IP, and Woods ID challenges. We monitored bacterial trafficking to the liver, lung, spleen, kidney, heart, and blood, and seroconversion during the 21-day challenge. Bacterial trafficking to all organs was observed in both the lethal and nonlethal models of infection, with significant increases in average bacterial loads observed in the livers and hearts of the lethal model. Multicolor flow cytometry was utilized to analyze the CD4+ and CD8+ T cell populations and their intracellular production of the cytokines IFNγ, TNF, and IL2 (single, double, and triple combinations) associated with both the lethal and nonlethal murine models of infection. The lethal model was defined by a cytokine signature of double- (IFNγ-IL2) and triple-producing (IL2-TNF-IFNγ) CD4+ T-cell populations; no multifunctional signature was identified in the CD8+ T-cell populations associated with the lethal model. In the nonlethal model, the cytokine signature was predominated by CD4+ and CD8+ T-cell populations associated with single (IL2) and/or double (IL2-TNF) populations of producers. The cytokine signatures associated with our lethal model will become depletion targets in future experiments; those signatures associated with our nonlethal model are hypothesized to be related to the protective nature of the nonlethal challenges.
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Silva-de la Fuente MC, Stekolnikov AA, Weitzel T, Beltrami E, Martínez-Valdebenito C, Abarca K, Acosta-Jamett G. Chigger Mites (Acariformes: Trombiculidae) of Chiloé Island, Chile, With Descriptions of Two New Species and New Data on the Genus Herpetacarus. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:646-657. [PMID: 33300548 DOI: 10.1093/jme/tjaa258] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Indexed: 06/12/2023]
Abstract
Three species of chigger mites are recorded in our collections from four species of cricetid rodents on Chiloé Island (southern Chile, Los Lagos Region), an area endemic to scrub typhus (Orientia sp.). Two species are described as new-Herpetacarus (Abonnencia) eloisae sp. nov. and Quadraseta chiloensis sp. nov. One species, Paratrombicula goffiStekolnikov and González-Acuña 2012, is for the first time recorded on a mammal host (one species of cricetid rodent), and its distribution is extended to the Los Lagos Region of Chile. The genus ProschoengastiaVercammen-Grandjean, 1967 is synonymized with the subgenus Herpetacarus (Abonnencia)Vercammen-Grandjean, 1960, and four new combinations are established: Herpetacarus (Abonnencia) herniosa (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) insolita (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) macrochaeta (Brennan and Jones, 1961), comb. nov., and Herpetacarus (Abonnencia) antarctica (Stekolnikov and Gonzalez-Acuña, 2015), comb. nov.
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Affiliation(s)
| | | | - Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Hantavirus and Zoonoses Program, Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Esperanza Beltrami
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Constanza Martínez-Valdebenito
- Laboratorio de Infectología y Virología Molecular, Red Salud UC-Christus, Santiago, Chile
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katia Abarca
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gerardo Acosta-Jamett
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
- Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
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Jiang J, Farris CM, Yeh KB, Richards AL. International Rickettsia Disease Surveillance: An Example of Cooperative Research to Increase Laboratory Capability and Capacity for Risk Assessment of Rickettsial Outbreaks Worldwide. Front Med (Lausanne) 2021; 8:622015. [PMID: 33738293 PMCID: PMC7960665 DOI: 10.3389/fmed.2021.622015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/20/2021] [Indexed: 01/30/2023] Open
Abstract
Cooperative research that addresses infectious disease surveillance and outbreak investigations relies heavily on availability and effective use of appropriate diagnostic tools, including serological and molecular assays, as exemplified by the current COVID-19 pandemic. In this paper, we stress the importance of using these assays to support collaborative epidemiological studies to assess risk of rickettsial disease outbreaks among international partner countries. Workforce development, mentorship, and training are important components in building laboratory capability and capacity to assess risk of and mitigate emerging disease outbreaks. International partnerships that fund cooperative research through mentoring and on-the-job training are successful examples for enhancing infectious disease surveillance. Cooperative research studies between the Naval Medical Research Center's Rickettsial Diseases Research Program (RDRP) and 17 institutes from nine countries among five continents were conducted to address the presence of and the risk for endemic rickettsial diseases. To establish serological and molecular assays in the collaborative institutes, initial training and continued material, and technical support were provided by RDRP. The laboratory methods used in the research studies to detect and identify the rickettsial infections included (1) group-specific IgM and IgG serological assays and (2) molecular assays. Twenty-six cooperative research projects performed between 2008 and 2020 enhanced the capability and capacity of 17 research institutes to estimate risk of rickettsial diseases. These international collaborative studies have led to the recognition and/or confirmation of rickettsial diseases within each of the partner countries. In addition, with the identification of specific pathogen and non-pathogen Rickettsia species, a more accurate risk assessment could be made in surveillance studies using environmental samples. The discoveries from these projects reinforced international cooperation benefiting not only the partner countries but also the scientific community at large through presentations (n = 40) at international scientific meetings and peer-reviewed publications (n = 18). The cooperative research studies conducted in multiple international institutes led to the incorporation of new SOPs and trainings for laboratory procedures; biosafety, biosurety, and biosecurity methods; performance of rickettsia-specific assays; and the identification of known and unknown rickettsial agents through the introduction of new serologic and molecular assays that complemented traditional microbiology methods.
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Affiliation(s)
- Ju Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Christina M. Farris
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | | | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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Landaeta-Aqueveque C, Moreno Salas L, Henríquez A, Silva-de la Fuente MC, González-Acuña D. Parasites of Native and Invasive Rodents in Chile: Ecological and Human Health Needs. Front Vet Sci 2021; 8:643742. [PMID: 33644158 PMCID: PMC7905021 DOI: 10.3389/fvets.2021.643742] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 01/20/2021] [Indexed: 01/30/2023] Open
Abstract
Invasive populations are a threat to biodiversity, resulting in the loss of species, and also a threat to human health, participating in the reservoir of diseases. Rodents are among the most important invasive species worldwide. Chile is a country that features island conditions in terms of geography and has been widely invaded by allochthonous rodents. In this mini-review, we updated the literature on macro-parasites infecting both native and invasive rodents and of vector-borne pathogens in continental Chile in order to assess the relative importance of invasive rodents from both ecological and public health points of view. A total of 174 parasite species were found, with Siphonaptera representing the most diverse group. When examining how parasites are shared between native and introduced rodents, the analysis suggests that parasites circulate freely within recipient populations, and are not significantly transmitted from source populations. Further, generalist parasites are typically more prone to being shared between native and introduced rodents. Most zoonotic parasites were reported in invasive rodents, suggesting that these rodents must represent a public health concern. Although several vector-borne pathogens have been reported in rodents or ectoparasites, most of the recently emerging research has illustrated that there is a lack of evidence on rodent-vector-borne zoonoses in most pathogens.
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Affiliation(s)
| | - Lucila Moreno Salas
- Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - AnaLía Henríquez
- Facultad de Medicina Veterinaria, Universidad San Sebastián, Concepción, Chile
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Elders PND, Swe MMM, Phyo AP, McLean ARD, Lin HN, Soe K, Htay WYA, Tanganuchitcharnchai A, Hla TK, Tun NN, Nwe TT, Moe MM, Thein WM, Zaw NN, Kyaw WM, Linn H, Htwe YY, Smithuis FM, Blacksell SD, Ashley EA. Serological evidence indicates widespread distribution of rickettsioses in Myanmar. Int J Infect Dis 2020; 103:494-501. [PMID: 33310022 PMCID: PMC7862081 DOI: 10.1016/j.ijid.2020.12.013] [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: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 11/26/2022] Open
Abstract
Diagnosis of rickettsial infections is difficult in low-resource settings; this leads to delays in receiving appropriate treatment. Before this study, the distribution of rickettsioses in Myanmar was not known. This serosurvey shows that rickettsioses are widespread in Myanmar. Particularly high prevalence of scrub typhus was found in central and northern regions.
Background Little research has been published on the prevalence of rickettsial infections in Myanmar. This study determined the seroprevalence of immunoglobulin G (IgG) antibodies to rickettsial species in different regions of Myanmar. Methods Seven hundred leftover blood samples from patients of all ages in primary care clinics and hospitals in seven regions of Myanmar were collected. Samples were screened for scrub typhus group (STG), typhus group (TG) and spotted fever group (SFG) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Immunofluorescence assays were performed for the same rickettsial groups to confirm seropositivity if ELISA optical density ≥0.5. Results Overall IgG seroprevalence was 19% [95% confidence interval (CI) 16–22%] for STG, 5% (95% CI 3–7%) for TG and 3% (95% CI: 2–5%) for SFG. The seroprevalence of STG was particularly high in northern and central Myanmar (59% and 19–33%, respectively). Increasing age was associated with higher odds of STG and TG seropositivity [per 10-year increase, adjusted odds ratio estimate 1.68 (p < 0.01) and 1.24 (p = 0.03), respectively]. Conclusion Rickettsial infections are widespread in Myanmar, with particularly high seroprevalence of STG IgG antibodies in central and northern regions. Healthcare workers should consider rickettsial infections as common causes of fever in Myanmar.
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Affiliation(s)
| | | | | | - Alistair R D McLean
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Kyaw Soe
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
| | | | - Ampai Tanganuchitcharnchai
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Thel K Hla
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Medical Action Myanmar, Yangon, Myanmar
| | - Ni Ni Tun
- Medical Action Myanmar, Yangon, Myanmar
| | - Thin Thin Nwe
- Magway General Hospital and University of Medicine, Magway, Myanmar; University of Medicine 2, Yangon, Myanmar
| | - Myat Myat Moe
- Magway General Hospital and University of Medicine, Magway, Myanmar
| | - Win May Thein
- Mandalay General Hospital and University of Medicine, Mandalay, Myanmar
| | - Ni Ni Zaw
- Mandalay General Hospital and University of Medicine, Mandalay, Myanmar
| | | | - Htun Linn
- Monywa General Hospital, Monywa, Myanmar
| | | | - Frank M Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; Medical Action Myanmar, Yangon, Myanmar
| | - Stuart D Blacksell
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Elizabeth A Ashley
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom; Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao Democratic People's Republic.
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Weitzel T, Aylwin M, Martínez-Valdebenito C, Acosta-Jamett G, Abarca K. Scrub typhus in Tierra del Fuego: a tropical rickettsiosis in a subantarctic region. Clin Microbiol Infect 2020; 27:S1198-743X(20)30719-9. [PMID: 33253942 DOI: 10.1016/j.cmi.2020.11.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/17/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile; Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.
| | - Mabel Aylwin
- Unidad de Infectología, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Constanza Martínez-Valdebenito
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gerardo Acosta-Jamett
- Instituto de Medicina Preventiva Veterinaria y Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Katia Abarca
- Departamento de Enfermedades Infecciosas e Inmunología Pediátricas, División de Pediatría, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
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Weitzel T, Makepeace BL, Elliott I, Chaisiri K, Richards AL, Newton PN. Marginalized mites: Neglected vectors of neglected diseases. PLoS Negl Trop Dis 2020; 14:e0008297. [PMID: 32701946 PMCID: PMC7377360 DOI: 10.1371/journal.pntd.0008297] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Benjamin L. Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Ivo Elliott
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
| | - Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Paul N. Newton
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
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