1
|
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] [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.
Collapse
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
| |
Collapse
|
2
|
Yan S, Lu Q, Tao Q, Lu Y, Gao B, Wang S, Cai X, Ai L, Xiong X, Cao M, Tan W. An immunochromatographic test for serological diagnosis of scrub typhus. J Immunol Methods 2024; 528:113653. [PMID: 38430991 DOI: 10.1016/j.jim.2024.113653] [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: 09/03/2023] [Revised: 01/24/2024] [Accepted: 02/27/2024] [Indexed: 03/05/2024]
Abstract
A fluorescent immunochromatographic test (FM-ICT) was developed for rapid detection of anti-Orientia tsutsugamushi antibodies in serum samples. The FM-ICT was constructed based on the dual-antigen sandwich method. Truncated 56 kDa outer membrane protein of O. tsutsugamushi strain SJ, was expressed in E. coli and mixed with those of Ptan and Gillam strains. A thin line of the protein mixture was precisely sprayed across a nitrocellulose membrane making this the "Test" line. Polyclonal antibodies (pAbs) to O.tsutsugamushi were sprayed in another line across the membrane making this the "Control" line. Fluorescent microspheres conjugated 56 kDa proteins reacting with sample serum will be captured on the "Test" line if the sample contains antibodies to O.tsutsugamushi. Several experimental parameters were optimized. After optimizing the reaction procedure, the results are visible, within 6 min, with the naked eye under ultraviolet light. The limit of detection (LOD) was determined to be 7.63 ng/mL with prepared polyclonal antibodies. No cross-reaction was observed with sera samples from other febrile diseases. In clinical evaluations, the strips showed 94.92% sensitivity (106/112) and 93.75% specificity (56/60). The FM-ICT we developed will provide a new tool for on-site diagnosis of scrub typhus.
Collapse
Affiliation(s)
- Shuhao Yan
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Qingyu Lu
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Qingyuan Tao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Yawei Lu
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Bao Gao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Sibo Wang
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Xusheng Cai
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Lele Ai
- Nanjing Bioengineering (Gene) Technology Center for Medicine, Nanjing 210002, PR China
| | - Xiaohui Xiong
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China
| | - Min Cao
- College Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, Jiangsu, PR China.
| | - Weilong Tan
- Nanjing Bioengineering (Gene) Technology Center for Medicine, Nanjing 210002, PR China.
| |
Collapse
|
3
|
Patil S, Patil A, Chaudhari S, Shinde S, Kolte S, Khan W, Kurkure N. Edifications on Indirect IgM ELISA and Immunofluorescence assay (IFA) of scrub typhus in humans and erudition of Orientia tsutsugamushi in the vector of cohabiting rodents. J Vector Borne Dis 2023; 60:244-251. [PMID: 37843234 DOI: 10.4103/0972-9062.355964] [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: 11/04/2022] Open
Abstract
Scrub typhus is a vector-borne disease caused by Orientia tsutsugamushi, propagated into humans by the bite of infected mite belonging to genus Leptotrombodium. The present study was conducted in the Nagpur region of central India aiming towards a survey of cohabiting rodents and their potential vectors for the presence of Orientia tsutsugamushi by PCR method. The study also emphasizes serological diagnosis of the disease by employing indirect IgM ELISA and IFA amongst the human cases of pyrexia of unknown origin. Indirect IgM ELISA recorded 39.69% (31/92) seropositive patients, further processing of ELISA positive samples for IFA revealed 67.74 % (21/31) positivity for Boryong, Gilliam, Karp, and Kato serotypes. A total of 50 rodents were trapped from the cohabit areas of the patients. Three different types of rodents were identified; among which, Rattus bandicoot was highest. From these rodents, 164 vectors viz mites, lice, and fleas were collected. The highest chiggar index was recorded for Ornithonyssus biscotti mites (3.4). This study prompts a detailed analysis of different species of rodents and vectors in the said endemic region.
Collapse
Affiliation(s)
- Shubham Patil
- Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, India
| | - Archana Patil
- Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, India
| | - Sandip Chaudhari
- Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, India
| | - Shilpshri Shinde
- Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, India
| | - Sunil Kolte
- Department of Veterinary Parasitology, Nagpur Veterinary College, Nagpur, India
| | - Waqar Khan
- Department of Veterinary Public Health, Nagpur Veterinary College, Nagpur, India
| | - Nitin Kurkure
- Maharashtra Animal and Fishery Sciences University, Nagpur, India
| |
Collapse
|
4
|
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.
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|