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Purushothaman S, Azhahianambi P, Dharman M, Gokula Kannan R, Tirumurugaan KG, Soundararajan C, Aravindh Babu RP, Devaraju P, Prakash JAJ. A cross sectional study on molecular prevalence of Orientia tsutsugamushi in household rat population of South India. Comp Immunol Microbiol Infect Dis 2024; 111:102212. [PMID: 38880051 DOI: 10.1016/j.cimid.2024.102212] [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: 03/18/2024] [Revised: 06/08/2024] [Accepted: 06/13/2024] [Indexed: 06/18/2024]
Abstract
This study aimed to assess the molecular prevalence of mite-borne zoonotic pathogen O. tsutsugamushi in household rats of South India through nested polymerase chain reaction amplification of O. tsutsugamushi 47-kDa htrA gene and to determine the most suitable sample type for screening of O. tsutsugamushi in rats. Out of 85 rats trapped in Tamil Nadu, Karnataka, and Puducherry regions, 47 rats were found positive for the O. tsutsugamushi genome with prevalence of 55.29 %. Among different sample types screened, faecal samples exhibited the highest positivity rate, followed by liver, spleen, kidney, and blood samples. Agreement between faecal and spleen samples of rats for the presence of O. tsutsugamushi was the highest. Principal component analysis revealed a positive correlation between the spleen, liver, and faeces and a negative correlation between blood and faeces for the presence of O. tsutsugamushi genome. These findings underscore the varied distribution of O. tsutsugamushi among different samples and indicate that the faecal and liver samples of rats are an ideal choice of samples for epidemiological studies. This is the first study to report a high level of presence of O. tsutsugamushi in faecal samples of rats.
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Affiliation(s)
- S Purushothaman
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | - P Azhahianambi
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India.
| | - M Dharman
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | - R Gokula Kannan
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | - K G Tirumurugaan
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | - C Soundararajan
- Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | - R P Aravindh Babu
- Translational Research Platform for Veterinary Biologicals, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai, Tamil Nadu 600051, India
| | | | - John A J Prakash
- Department of Clinical Microbiology, Christian Medical College, Vellore 632004, India
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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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Kaura T, Kaur J, Bisht K, Goel S, Lakshmi P, Grover GS, Mewara A, Biswal M. Vector and rodent surveillance for Orientia tsutsugamushi in north India. J Vector Borne Dis 2022; 59:348-355. [PMID: 36751766 DOI: 10.4103/0972-9062.355958] [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: 11/04/2022] Open
Abstract
BACKGROUND & OBJECTIVES Scrub typhus or chigger borne typhus, caused by Orientia tsutsugamushi is an emerging vector-borne disease as large numbers of cases have been reported in various tropical countries. It is transmitted to humans through bites of infected chiggers (larval mites). The knowledge about the vector, its distribution, density and habitat are important so as to understand the epidemiology of scrub typhus in a given area. To control rickettsial infections, regular rodent-vector surveillance should be planned in areas where the disease transmission is occurring and it will also help to strengthen the existing entomological data related to the vector of scrub typhus in northern India. METHODS In the present study, rodent-vector surveillance was planned for one whole year, covering both mite active and non-active seasons (October 2019-December 2020) in selected areas of Chandigarh and Punjab in north India. Rodent tissues and mites were also examined for the presence of O. tsutsugamushi by nested PCR for 56 kDa gene and real-time PCR for 47 kDa outer membrane protein gene. 18S gene PCR was performed for molecular identification of mites. RESULTS In the surveillance, three types of ectoparasite, viz. mites, fleas and ticks were obtained in rodents. All mites found were of Laelapidae family. None of the pooled rodent tissue samples as well as mite samples were found positive for O. tsutsugamushi by nested PCR for rickettsial DNA. INTERPRETATION & CONCLUSION In the present study, we did not get any evidence of carriage of O. tsutsugamushi in either mites or rodents collected and sampled in selected regions in Chandigarh and Punjab. We need to strengthen the entomological surveillance over a broader region and increase the frequency of trapping rodents to increase clarity on vector-reservoir dynamics in this geographical region.
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Affiliation(s)
- Taruna Kaura
- Department of Medical Parasitology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Jasleen Kaur
- Department of Medical Microbiology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Kamlesh Bisht
- Department of Medical Microbiology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shriya Goel
- Department of Medical Microbiology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Pvm Lakshmi
- Department of Community Medicine and School of Public Health, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Gagandeep Singh Grover
- Department of Health and Family Welfare, Punjab, Parivar Kalyan Bhawan, Chandigarh, India
| | - Abhishek Mewara
- Department of Medical Parasitology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Manisha Biswal
- Department of Medical Microbiology; Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Panda S, Swain SK, Sahu BP, Sarangi R. Gene expression and involvement of signaling pathways during host-pathogen interplay in Orientia tsutsugamushi infection. 3 Biotech 2022; 12:180. [PMID: 35860421 PMCID: PMC9295102 DOI: 10.1007/s13205-022-03239-7] [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: 04/01/2022] [Accepted: 06/18/2022] [Indexed: 11/22/2022] Open
Abstract
Scrub typhus is a neglected tropical disease that affects one-third of the world’s population. The disease is caused by Orientia tsutsugamushi (OT), an obligate intracellular Gram-negative bacterium. OT efficiently escapes from the endosomal pathway after entering the host cell and replicates inside cytosol. OT infection promotes cellular autophagy, the autonomous defense mechanism unlike other bacteria. This study has discussed the bacterial invasion process through the extracellular matrix and the immune response activated by the bacterium within the hosts. Furthermore, we have emphasized the importance of extracellular matrix and their cross-talk with the immune cells, such as, macrophages, neutrophils, and dendritic cells followed by their inflammatory response. We have also put an insight into the host factors associated with signaling pathways during scrub typhus disease with a special focus on the OT-induced stress response, autophagy, apoptosis, and innate immunity. Multiple cytokines and chemokines play a significant role in activating different immune-related signaling pathways. Due to the presence of high antigenic diversity among strains, the signaling pathways during the host–pathogen interplay of OT with its host is very complicated. Thus, it hinders to mitigate the severity of the pandemic occurred by the respective pathogen. Our investigation will provide a useful guide to better understand the virulence and physiology of this intracellular pathogen which will lead towards a better therapeutic diagnosis and vaccine development.
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Affiliation(s)
- Subhasmita Panda
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Subrat Kumar Swain
- Centre for Genomics and Biomedical Informatics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Basanta Pravas Sahu
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore 453552 India
| | - Rachita Sarangi
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
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Prakash JAJ, Kamarasu K, Samuel PP, Govindarajan R, Govindasamy P, Johnson LA, Ramalingam P, Nirmalson J, Seran KC. Detection of Orientia tsutsugamushi in Novel Trombiculid Mite Species in Northern Tamil Nadu, India: Use of Targeting the Multicopy traD Gene. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:693-699. [PMID: 34850037 DOI: 10.1093/jme/tjab180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Detection of Orientia tsutsugamushi DNA in a trombiculid mite chigger species suggests that it might be a potential vector of scrub typhus in an endemic area. Over a period of 20 mo, 85 rats were trapped, 57 had chiggers that were identified by standard morphometric techniques. The chigger pools were assessed by performing PCR assays targeting fragments of the single-copy genes 56 kDa type-specific antigen gene (TSA56) by nested PCR and the 47 kDa (htrA) quantitative real-time PCR (qPCR). The novel traD SYBR green assay that detects a multicopy gene was also performed. In total, 27 chigger pools were positive by traD qPCR, of which only 7 were positive by 47 kDa qPCR and in 3 of these, 56 kDa gene was amplified by nested PCR. Orientia tsutsugamushi-specific DNA was detected in Ascoschoengastia spp., Schoengastiella ligula, Leptotrombidium rajasthanense, Leptotrombidium deliense, and Leptotrombidium jayawickremei chigger pools. Therefore, they could be potential vectors of scrub typhus in Southern India. The three 56 kDa sequences belonged to TA716 genotype and Kato genogroup. Further studies are needed to confirm these chigger species as scrub typhus vectors in Northern Tamil Nadu.
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Affiliation(s)
- John Antony Jude Prakash
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - Kannan Kamarasu
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - P Philip Samuel
- ICMR-Vector Control Research Centre Field Station, 4, Sarojini St, Chinna Chokikulam, Madurai Tamil Nadu 625002, India
| | - Renu Govindarajan
- ICMR-Vector Control Research Centre Field Station, 4, Sarojini St, Chinna Chokikulam, Madurai Tamil Nadu 625002, India
| | - Punitha Govindasamy
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - Liji Anna Johnson
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - P Ramalingam
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - J Nirmalson
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - K C Seran
- Department of Community Medicine, Madras Medical College, Near Park Town Station, Chennai, Tamil Nadu 600003, India
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Chaudhari SP, Kalorey DR, Awandkar SP, Kurkure NV, Narang R, Kashyap RS, Rahi M, Barbuddhe SB. Journey towards National Institute of One Health in India. Indian J Med Res 2021; 153:320-326. [PMID: 33906994 PMCID: PMC8204833 DOI: 10.4103/ijmr.ijmr_636_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background & objectives Issues such as emerging and re-emerging infectious diseases, antimicrobial resistance, food security, biosafety and biosecurity are associated with changes in land use, population growth, urbanization, global travel and trade and climate change. As a result, a trans-disciplinary approach among human, animal and environmental health disciplines gained support. The Indian Council of Medical Research (ICMR) and Indian Council of Agricultural Research (ICAR) decided to establish a National Institute of One Health at Nagpur, Maharashtra, India. In this context, two collaborative research projects, funded by the ICAR and ICMR were initiated to conduct the epidemiological surveillance of selected zoonotic diseases in Central India. Methods Disease surveillance and molecular detection employing standard techniques like enzyme linked immunosorbent assay (ELISA), immuno-fluroscent assay (IFA), standard tube agglutination test (STAT) , Rose Bengal plate test (RBPT) and polymerase chain reaction (PCR) were undertaken based on the disease to be screened. Results In animals, the seropositivities for listeriosis (7.66%) and brucellosis (11.69%) were recorded. The occurrence of tuberculosis (3.8%) and leptospirosis (6.33%) was detected by PCR. Through cross-sectional studies from suspected human population with associated risk factors for zoonotic diseases, the seropositivity of brucellosis (1.83-11%), listeriosis (1.01-10.18 %), leptospirosis (8.14-12.67%) and scrub typhus (1.78-20.34%) was recorded. The investigations on scrub typhus indicated bimodal pattern during the months of pre-monsoon and post-monsoon season with a peak in post-monsoon in human cases. Ornithonyssus bacoti mites were identified from the rodents as a vector harbouring Orientia tsutsugamushi. The bovine tuberculosis was detected in 1.43 per cent human cases employing molecular assay. Interpretation & conclusions The data indicated the occurrence of important zoonotic diseases adversely affecting the livestock health and human wellbeing. The scientific collaboration between veterinary and medical faculties has set an example for effective implementation of One Health (OH) programme for the establishment of National Institute of OH.
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Affiliation(s)
- Sandeep P Chaudhari
- Centre for Zoonoses, Nagpur Veterinary College, Maharashtra Animal & Fishery Science University, Nagpur, Maharashtra, India
| | - Dewanand R Kalorey
- Centre for Zoonoses, Nagpur Veterinary College, Maharashtra Animal & Fishery Science University, Nagpur, Maharashtra, India
| | - Sudhakar P Awandkar
- Centre for Zoonoses, Nagpur Veterinary College, Maharashtra Animal & Fishery Science University, Nagpur, Maharashtra, India
| | - Nitin V Kurkure
- Centre for Zoonoses, Nagpur Veterinary College, Maharashtra Animal & Fishery Science University, Nagpur, Maharashtra, India
| | - Rahul Narang
- Department of Microbiology, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Maharashtra, India
| | - Rajpal S Kashyap
- Research Centre, Central India Institute of Medical Sciences, Nagpur, Maharashtra, India
| | - Manju Rahi
- Division of Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi, India
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Zhao Y, Zhang WY, Wang RL, Niu DL. Divergent domains of 28S ribosomal RNA gene: DNA barcodes for molecular classification and identification of mites. Parasit Vectors 2020; 13:251. [PMID: 32404192 PMCID: PMC7222323 DOI: 10.1186/s13071-020-04124-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The morphological and molecular identification of mites is challenging due to the large number of species, the microscopic size of the organisms, diverse phenotypes of the same species, similar morphology of different species and a shortage of molecular data. METHODS Nine medically important mite species belonging to six families, i.e. Demodex folliculorum, D. brevis, D. canis, D. caprae, Sarcoptes scabiei canis, Psoroptes cuniculi, Dermatophagoides farinae, Cheyletus malaccensis and Ornithonyssus bacoti, were collected and subjected to DNA barcoding. Sequences of cox1, 16S and 12S mtDNA, as well as ITS, 18S and 28S rDNA from mites were retrieved from GenBank and used as candidate genes. Sequence alignment and analysis identified 28S rDNA as the suitable target gene. Subsequently, universal primers of divergent domains were designed for molecular identification of 125 mite samples. Finally, the universality of the divergent domains with high identification efficiency was evaluated in Acari to screen DNA barcodes for mites. RESULTS Domains D5 (67.65%), D6 (62.71%) and D8 (77.59%) of the 28S rRNA gene had a significantly higher sequencing success rate, compared to domains D2 (19.20%), D3 (20.00%) and D7 (15.12%). The successful divergent domains all matched the closely-related species in GenBank with an identity of 74-100% and a coverage rate of 92-100%. Phylogenetic analysis also supported this result. Moreover, the three divergent domains had their own advantages. D5 had the lowest intraspecies divergence (0-1.26%), D6 had the maximum barcoding gap (10.54%) and the shortest sequence length (192-241 bp), and D8 had the longest indels (241 bp). Further universality analysis showed that the primers of the three divergent domains were suitable for identification across 225 species of 40 families in Acari. CONCLUSIONS This study confirmed that domains D5, D6 and D8 of 28S rDNA are universal DNA barcodes for molecular classification and identification of mites. 28S rDNA, as a powerful supplement for cox1 mtDNA 5'-end 648-bp fragment, recommended by the International Barcode of Life (IBOL), will provide great potential in molecular identification of mites in future studies because of its universality.
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Affiliation(s)
- Yae Zhao
- Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China.
| | - Wan-Yu Zhang
- Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China
| | - Rui-Ling Wang
- Assisted Reproduction Center, Northwest Women's and Children's Hospital, Xi'an, 710003, Shaanxi, People's Republic of China
| | - Dong-Ling Niu
- Department of Pathogen Biology and Immunology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, People's Republic of China
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Elliott I, Pearson I, Dahal P, Thomas NV, Roberts T, Newton PN. Scrub typhus ecology: a systematic review of Orientia in vectors and hosts. Parasit Vectors 2019; 12:513. [PMID: 31685019 PMCID: PMC6829833 DOI: 10.1186/s13071-019-3751-x] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/12/2019] [Indexed: 01/06/2023] Open
Abstract
Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites ('chiggers') and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.
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Affiliation(s)
- Ivo Elliott
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Isabelle Pearson
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Prabin Dahal
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Worldwide Anti Malarial Resistance Network, University of Oxford, Oxford, UK
- Linacre College, University of Oxford, St Cross Road, Oxford, UK
| | - Nigel V. Thomas
- Worldwide Anti Malarial Resistance Network, University of Oxford, Oxford, UK
| | - Tamalee Roberts
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Paul N. Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Worldwide Anti Malarial Resistance Network, University of Oxford, Oxford, UK
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Lu M, Li F, Liao Y, Shen JJ, Xu JM, Chen YZ, Li JH, Holmes EC, Zhang YZ. Epidemiology and Diversity of Rickettsiales Bacteria in Humans and Animals in Jiangsu and Jiangxi provinces, China. Sci Rep 2019; 9:13176. [PMID: 31511528 PMCID: PMC6739303 DOI: 10.1038/s41598-019-49059-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 08/19/2019] [Indexed: 11/09/2022] Open
Abstract
Diseases caused by Rickettsiales bacteria are a global public health problem. To better understand the diversity and origins of Rickettsiales infection in humans and animals, we sampled 134 febrile patients, 173 rodents and 43 shrews, as well as 358 ticks, from two cities in Jiangsu and Jiangxi provinces, China. Our data revealed a relatively high prevalence of scrub typhus cases in both localities. In addition, both serological tests and genetic analysis identified three patients infected with Anaplasma bovis, Rickettsia monacensis, and Orientia tsutsugamushi bacteria. Molecular epidemiological investigation revealed the co-circulation of multiple species of Rickettsiales bacteria in small mammals and ticks in both provinces, potentially including novel bacterial species. In sum, these data demonstrate the ongoing importance of Rickettsiales infection in China and highlight the need for the regular surveillance of local arthropods, mammals and humans.
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Affiliation(s)
- Miao Lu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China
| | - Feng Li
- Yancheng Center for Disease Control and Prevention, Yancheng, Jiangsu province, China
| | - Yong Liao
- Ganzhou Center for Disease Control and Prevention, Ganzhou, Jiangxi province, China
| | - Jin-Jin Shen
- Yancheng Center for Disease Control and Prevention, Yancheng, Jiangsu province, China
| | - Jian-Min Xu
- Jiangxi Center for Disease Control and Prevention, Nanchang, Jiangxi province, China
| | - Yin-Zhong Chen
- Yancheng Center for Disease Control and Prevention, Yancheng, Jiangsu province, China
| | - Jian-Hua Li
- Ganzhou Center for Disease Control and Prevention, Ganzhou, Jiangxi province, China
| | - Edward C Holmes
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China.,Marie Bashir Institute for Infectious Diseases and Biosecurity, Charles Perkins Centre, School of Life and Environmental Sciences and Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia.,Shanghai Public Health Clinical Center & Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Yong-Zhen Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Changping, Beijing, China. .,Shanghai Public Health Clinical Center & Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
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Akhunji B, Bhate R, Pansare N, Chaudhari SP, Khan W, Kurkure NV, Kolte SW, Barbuddhe SB. Distribution of Orientia tsutsugamushi in rodents and mites collected from Central India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:82. [PMID: 30656500 DOI: 10.1007/s10661-019-7208-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Orientia tsutsugamushi, the causative agent of scrub typhus, is an obligate intracytosolic bacterium transmitted among humans and small mammals by some species of larval trombiculid mites (chiggers). It has been recognized as a pathogen of major public health concern in the Asia-Pacific region. As disease is considered as a neglected, there exists a gap in our knowledge of the disease with regard to the sporadic epidemiologic data in endemic areas. The purpose of the study was to find out the vector as well as pathogen distribution in rodents present in the scrub typhus-reported areas in central India. We studied the seasonal variations of occurrence in O. tsutsugamushi in rodents and mites by molecular detection targeting the 56-kDa and 47-kDa genes. Rodent and mite samples were collected during December 2015 to July 2017. A total of 127 samples from rodents, seven pools of mites, and four pools of fleas were collected and processed for DNA isolation. Nested PCRs targeting the 56-kDa and 47-kDa surface antigen genes were performed. In addition, quantification of bacterial load was done by qPCR targeting the 47-kDa gene. During the pre-monsoon season, O. tsutsugamushi was detected in 12% and 10% samples employing the 56-kDa and 47-kDa nested PCRs, respectively, whereas, during post-monsoon season, the respective detection rates were 13.33% and 26.66%. This study predicted a bimodal pattern during the months of pre-monsoon and post-monsoon season with a peak in post-monsoon. Thus, the impact of season on the perpetuation of O. tsutsugamushi in the host was observed.
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Affiliation(s)
- Batul Akhunji
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - Ruchi Bhate
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - Nilesh Pansare
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - S P Chaudhari
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India.
| | - Waqar Khan
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - N V Kurkure
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - S W Kolte
- Centre for Zoonoses, Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra Animal and Fishery Sciences University, Nagpur, 440006, India
| | - S B Barbuddhe
- ICAR-National Research Centre on Meat, Hyderabad, 500092, India.
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Complexity of type-specific 56 kDa antigen CD4 T-cell epitopes of Orientia tsutsugamushi strains causing scrub typhus in India. PLoS One 2018; 13:e0196240. [PMID: 29698425 PMCID: PMC5919512 DOI: 10.1371/journal.pone.0196240] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/09/2018] [Indexed: 01/31/2023] Open
Abstract
Orientia tsutsugamushi (Ots) is an obligate, intracellular, mite-transmitted human pathogen which causes scrub typhus. Understanding the diversity of Ots antigens is essential for designing specific diagnostic assays and efficient vaccines. The protective immunodominant type-specific 56 kDa antigen (TSA) of Ots varies locally and across its geographic distribution. TSA contains four hypervariable domains. We bioinformatically analyzed 345 partial sequences of TSA available from India, most of which contain only the three variable domains (VDI-III) and three spacer conserved domains (SVDI, SVDII/III, SVDIII). The total number (152) of antigenic types (amino acid variants) varied from 14–36 in the six domains of TSA that we studied. Notably, 55% (787/1435) of the predicted CD4 T-cell epitopes (TCEs) from all the six domains had high binding affinities (HBA) to at least one of the prevalent Indian human leukocyte antigen (HLA) alleles. A surprisingly high proportion (61%) of such TCEs were from spacer domains; indeed 100% of the CD4 TCEs in the SVDI were HBA. TSA sequences from India had more antigenic types (AT) than TSA from Korea. Overall, >90% of predicted CD4 TCEs from spacer domains were predicted to have HBA against one or more prevalent HLA types from Indian, Korean, Asia-Pacific region or global population data sets, while only <50% of CD4 TCEs in variable domains exhibited such HBA. The phylogenetically and immunologically important amino acids in the conserved spacer domains were identified. Our results suggest that the conserved spacer domains are predicted to be functionally more important than previously appreciated in immune responses to Ots infections. Changes occurring at the TCE level of TSA may contribute to the wide range of pathogenicity of Ots in humans and mouse models. CD4 T-cell functional experiments are needed to assess the immunological significance of these HBA spacer domains and their role in clearance of Ots from Indian patients.
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