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Rattanakomol P, Khongwichit S, Poovorawan Y. Flea-Borne Rickettsioses and Scrub Typhus in Patients with Suspected Arbovirus Infection in Bangkok, Thailand. Vector Borne Zoonotic Dis 2024. [PMID: 38946645 DOI: 10.1089/vbz.2024.0030] [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: 07/02/2024] Open
Abstract
Background: In urban Thailand, arboviral infections dominate diagnoses of acute undifferentiated fevers (AUFs) owing to their well-defined epidemiology and characteristic clinical presentations. However, rickettsial diseases, also endemic in this setting, remain under-recognized owing to challenges in early detection. Objective: This study aimed to identify potential rickettsial infections among patients with AUF in Bangkok and vicinity utilizing leftover nucleic acid extracted from serum samples from patients initially suspected of but negative for arbovirus infections. Materials and Methods: A total of 609 nucleic acid samples were screened for rickettsial bacteria using real-time PCR, targeting the 17-kDa common antigen gene of Rickettsia spp. and the 47-kDa gene of Orientia tsutsugamushi. Results: Nine samples were positive for Rickettsia spp. and two were positive for O. tsutsugamushi. DNA sequence and phylogenetic analyses based on partial 17-kDa antigen and citrate synthase (gltA) genes identified the Rickettsia-positive samples as R. typhi in eight cases and R. felis in one case. Analysis of the 56-kDa type-specific antigen gene identified the two O. tsutsugamushi isolates as Gilliam-related genotypes. Although rickettsial diseases typically present with mild symptoms, two patients with R. typhi infection (murine typhus) developed respiratory distress syndrome, highlighting the potential for rare but serious complications. Conclusion: This study underscores the critical importance of differential diagnosis and prompt, effective intervention to prevent complications in suspected cases.
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Affiliation(s)
- Patthaya Rattanakomol
- Department of Pediatrics, Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Sarawut Khongwichit
- Department of Pediatrics, Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Yong Poovorawan
- Department of Pediatrics, Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Eikenbary B, Devaraju P, Chakkravarthi A, Sihag KK, Nathan T, Thangaraj G, Srinivasan L, Kumar A. A molecular survey of zoonotic pathogens of public health importance in rodents/shrews and their ectoparasites trapped in Puducherry, India. Trans R Soc Trop Med Hyg 2024:trae033. [PMID: 38768316 DOI: 10.1093/trstmh/trae033] [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: 11/24/2023] [Revised: 03/18/2024] [Accepted: 04/26/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND Globally, India has a high zoonotic disease burden and lacks surveillance data in humans and animals. Rodents are known reservoirs for many zoonotic diseases and their synanthropic behavior poses a great public health threat. METHODS In this study, trapped rodents/shrews from randomly selected villages within Puducherry, India, and their ectoparasites were screened for zoonotic pathogens, namely, Orientia tsutsugamushi, other pathogenic rickettsiae, Leptospira spp., Cryptosporidium spp., Coxiella burnetii and methicillin-resistant Staphylococcus aureus (MRSA) using conventional PCR. A total of 58 rodents/shrews were trapped from 11 villages. The species trapped were Suncus murinus (49/58, 84.48%), Rattus rattus (8/58, 13.79%) and Rattus norvegicus (1/58, 1.72%). All ectoparasites collected were identified as mites and its infestation rate was 46.55% (27/58). RESULTS Real-time PCR targeting the 47 kDa gene of O. tsutsugamushi revealed positivity in one rodent and one shrew (3.45%) and two mite pools (7.41%). Conventional PCR targeting the 56 kDa gene revealed positivity in one shrew and two mite pools and the phylogenetic analysis of all three amplicons indicated the circulation of the Gilliam-related serotype. MRSA was detected in the alimentary tract of a shrew (1/32, 3.13%). Leptospira spp., Rickettsia, Cryptosporidium spp. and Co. burnetii tested negative. CONCLUSIONS The detection of zoonotic pathogens within reservoir hosts and vectors poses a risk of transmission to humans. This study signifies the need for zoonotic pathogen surveillance in synanthropic rodents/shrews.
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Affiliation(s)
- Brenna Eikenbary
- Department of Global Health, Georgetown University, Washington DC, 20057, USA
| | - Panneer Devaraju
- Unit of One Health, ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
| | | | - Krishan Kumar Sihag
- Unit of One Health, ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
| | - Terence Nathan
- Unit of One Health, ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
| | - Gowdham Thangaraj
- Unit of One Health, ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
| | - Lakshmy Srinivasan
- Unit of One Health, ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
| | - Ashwani Kumar
- ICMR-Vector Control Research Centre (ICMR-VCRC), Puducherry 605006, India
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Ritu GP, Arif W, Sihag KK, Chakravarthi A, Anthony TN, Srinivasan L, Balakrishnan V, Kumar A, Ayanar E, Devaraju P. Comparative Evaluation of Different Tissues and Molecular Techniques for the Zoonotic Surveillance of Scrub Typhus. Vector Borne Zoonotic Dis 2024; 24:299-307. [PMID: 38181193 DOI: 10.1089/vbz.2023.0069] [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: 01/07/2024] Open
Abstract
Background and Objectives: Scrub typhus (ST) is detected in one-fourth of patients with acute febrile illnesses, confirming its nationwide re-emergence. The disease, if not diagnosed, can lead to multiple organ dysfunction and mortality. Being a vector-borne zoonotic disease, the molecular survey for pathogens in animal hosts is essential to predict the risk of its transmission to humans. Hence, this study aimed at identifying the effective animal tissue and molecular technique for zoonotic surveillance of ST infection in small animal hosts. Methods: Rodents/shrews were trapped from seventeen randomly selected villages in Puducherry between July and September, 2022. The presence of Orientia tsutsugamushi in ectoparasites and tissues including blood, lung, liver, spleen, kidney, heart, brain, and intestine retrieved from the animals was screened by nested PCR targeting 56 kDa, real-time PCR (qPCR) targeting 47 kDa and traD, and conventional PCR targeting groEL. The Weil-Felix test was carried out to detect antibodies against O. tsutsugamushi in rodent/shrew serum samples. Diagnostic accuracy measures of the molecular tests were calculated for each of the tissues by latent class modeling. Results: O. tsutsugamushi detected in the rodents/shrews were identified to be Karp-like and Kawasaki-like strains. Upon statistical analysis, qPCR targeting 47 kDa exhibited the highest accuracy measures in most of the tissues analyzed, with perfect sensitivity and specificity of 100% and 97% for intestine and lung samples for the epidemiological surveillance, respectively. Interpretation and Conclusion: The study recommends qPCR targeting 47 kDa gene and analysis of intestine and lung along with blood for the zoonotic surveillance of ST infection.
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Affiliation(s)
- Georgina Parren Ritu
- MSc. Public Health Entomology Student, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | - Waseema Arif
- Unit of One Health, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | - Krishan Kumar Sihag
- Unit of One Health, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | | | | | - Lakshmy Srinivasan
- Unit of One Health, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | | | - Ashwani Kumar
- ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | - Elango Ayanar
- Unit of Vector Biology and Control, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
| | - Panneer Devaraju
- Unit of One Health, ICMR-Vector Control Research Centre, Indira Nagar, Puducherry
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Balasubramanian T, Sambath U, Radja RD, Thangaraj G, Devaraju P, Srinivasan L, Srinivasan P, Nair MG, Raja K, Lakkawar AW, Soong L. Pathological Responses in Asian House Shrews ( Suncus murinus) to the Naturally Acquired Orientia tsutsugamushi Infection. Microorganisms 2024; 12:748. [PMID: 38674692 PMCID: PMC11051718 DOI: 10.3390/microorganisms12040748] [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: 02/05/2024] [Revised: 03/28/2024] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Scrub typhus is a re-emerging disease caused by Orientia tsutsugamushi, transmitted by mites belonging to the family Trombiculidae. Humans and rodents acquire the infection by the bite of larval mites/chiggers. Suncus murinus, the Asian house shrew, has been reported to harbor the vector mites and has been naturally infected with O. tsutsugamushi. The present study aimed to localize and record O. tsutsugamushi in the tissues and the host response in shrews naturally infected with O. tsutsugamushi. Sheehan's modified May-Grunwald Giemsa staining was carried out in 365 tissues from 87 animals, and rickettsiae were documented in 87 tissues from 20 animals. Immunohistochemical (IHC) staining, using polyclonal antibodies raised against selected epitopes of the 56-kDa antigen, was carried out, and 81/87 tissue sections were tested positive for O. tsutsugamushi. By IHC, in addition to the endothelium, the pathogen was also demonstrated by IHC in cardiomyocytes, the bronchiolar epithelium, stroma of the lungs, hepatocytes, the bile duct epithelium, the epithelium and goblet cells of intestine, the tubular epithelium of the kidney, and splenic macrophages. Furthermore, the pathogen was confirmed by real-time PCR using blood (n = 20) and tissues (n = 81) of the IHC-positive animals. None of the blood samples and only 22 out of 81 IHC-positive tissues were tested positive by PCR. By nucleotide sequencing of the 56-kDa gene, Gilliam and Karp strains were found circulating among these animals. Although these bacterial strains are highly virulent and cause a wide range of pathological alterations, hence exploring their adaptive mechanisms of survival in shrews will be of significance. Given that the pathogen localizes in various organs following a transient bacteremia, we recommend the inclusion of tissues from the heart, lung, intestine, and kidney of reservoir animals, in addition to blood samples, for future molecular surveillance of scrub typhus.
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Affiliation(s)
- Tharani Balasubramanian
- Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry 605009, India; (T.B.); (U.S.); (M.G.N.); (K.R.); (A.W.L.)
| | - Uma Sambath
- Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry 605009, India; (T.B.); (U.S.); (M.G.N.); (K.R.); (A.W.L.)
| | - Ranjana Devi Radja
- Unit of One Health, ICMR—Vector Control Research Centre, Indira Nagar, Puducherry 605006, India; (R.D.R.); (G.T.); (L.S.); (P.S.)
| | - Gowdham Thangaraj
- Unit of One Health, ICMR—Vector Control Research Centre, Indira Nagar, Puducherry 605006, India; (R.D.R.); (G.T.); (L.S.); (P.S.)
| | - Panneer Devaraju
- Unit of One Health, ICMR—Vector Control Research Centre, Indira Nagar, Puducherry 605006, India; (R.D.R.); (G.T.); (L.S.); (P.S.)
| | - Lakshmy Srinivasan
- Unit of One Health, ICMR—Vector Control Research Centre, Indira Nagar, Puducherry 605006, India; (R.D.R.); (G.T.); (L.S.); (P.S.)
| | - Pushpa Srinivasan
- Unit of One Health, ICMR—Vector Control Research Centre, Indira Nagar, Puducherry 605006, India; (R.D.R.); (G.T.); (L.S.); (P.S.)
| | - Madhavan Gopalakrishnan Nair
- Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry 605009, India; (T.B.); (U.S.); (M.G.N.); (K.R.); (A.W.L.)
| | - Kumar Raja
- Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry 605009, India; (T.B.); (U.S.); (M.G.N.); (K.R.); (A.W.L.)
| | - Avinash Warundeo Lakkawar
- Department of Veterinary Pathology, Rajiv Gandhi Institute of Veterinary Education and Research, Kurumbapet, Puducherry 605009, India; (T.B.); (U.S.); (M.G.N.); (K.R.); (A.W.L.)
| | - Lynn Soong
- Department of Microbiology and Immunology, Institute for Human Infections & Immunity, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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Kabir KI, Satapathy AK, Gullla KM, John J, Dwibedi B, Mahapatro S, Das RR. Macrolides versus other antibiotics in pediatric scrub typhus: A meta-analysis. Indian J Med Microbiol 2023; 46:100460. [PMID: 37945110 DOI: 10.1016/j.ijmmb.2023.100460] [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: 04/23/2023] [Revised: 07/02/2023] [Accepted: 08/03/2023] [Indexed: 09/18/2023]
Abstract
BACKGROUND While Doxycycline is the recommended drug for treating scrub typhus, there is a growing trend of using Macrolides and Other antibiotics due to their perceived advantages. In this study, we compared the efficacy of Macrolides versus Other antibiotics in the treatment of pediatric scrub typhus. METHODS Meta-analysis of randomized controlled trials (RCTs) with GRADE (Grading of Recommendations, Assessment, Development and Evaluation) application. Major databases were searched till 30th December 2022. Children of all age groups were included. Primary outcomes included mortality rate and time to defervescence (h). RESULTS Of the 103 citations retrieved, 5 trials, including 383 children up to 15 years of age with probable and confirmed cases of scrub typhus, were included. None of the trials reported mortality rate. The pooled results from the trials found no significant difference between Azithromycin and Other antibiotics for any of the outcome measures. The certainty of evidence for the primary outcome was deemed to be of "very low certainty", while the certainty of evidence for the secondary outcomes ranged from "low to moderate certainty". CONCLUSIONS The current meta-analysis revealed that there was no significant difference between Azithromycin and Other antibiotics (such as Doxycycline and Chloramphenicol) in the treatment of scrub typhus in children. However, it's important to note that the evidence generated for the primary outcome was of "very low certainty". PROSPERO REGISTRATION NUMBER CRD42021276577.
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Affiliation(s)
| | | | | | - Joseph John
- Department of Pediatrics, AIIMS, Bhubaneswar, 751019, India.
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Bhandari M, Singh RK, Laishevtcev A, Mohapatra TM, Nigam M, Mori E, Vasconcelos de Lacerda BCG, Coutinho HDM, Mishra AP. Revisiting scrub typhus: A neglected tropical disease. Comp Immunol Microbiol Infect Dis 2022; 90-91:101888. [PMID: 36252451 DOI: 10.1016/j.cimid.2022.101888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/18/2022] [Accepted: 09/29/2022] [Indexed: 02/08/2023]
Abstract
Scrub typhus is an under diagnosed re-emerging vector borne disease caused by an intracellular gram negative bacteria, Orientia. The disease is commonly prevalent in rural and hilly areas of Tsutsugumashi triangle. The diagnosis of the disease is very challenging due to similarity of its early symptoms with other febrile illnesses, like dengue and COVID 19, as well as non-availability of rapid, reliable and cost-effective methods. Moreover, the diverse clinical presentation in severe cases make it significant health problem. The occupational and behavioral risks responsible for the transmission lead to urgent need of vaccine development against the disease. The complete knowledge about its pathogenesis and the interaction with host's immune cells may help the scientists in developing the appropriate diagnostic methods as well as the vaccines.
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Affiliation(s)
- Munni Bhandari
- Department of Microbiology, School of Life Sciences, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Garhwal) 246174, India.
| | - Rahul Kunwar Singh
- Department of Microbiology, School of Life Sciences, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Garhwal) 246174, India.
| | - Alexey Laishevtcev
- Federal Research Center - All-Russian Scientific Research Institute of Experimental Veterinary Medicine named after K.I. Skryabin and Y.R. Kovalenko of the Russian Academy of Sciences, Moscow, Russia; Laboratory of Biocontrol and Antimicrobial Resistance, Orel State, University Named After I.S. Turgenev, Orel, Russia.
| | - Tribhuvan Mohan Mohapatra
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
| | - Manisha Nigam
- Department of Biochemistry, Hemvati Nandan Bahuguna Garhwal University, Srinagar Garhwal-246174, Uttarakhand, India.
| | - Edna Mori
- CECAPE - College of Dentistry, Av. Padre Cícero, 3917, Juazeiro do Norte, São José CE 63024-015, Brazil.
| | | | | | - Abhay Prakash Mishra
- Department of Pharmacology, Faculty of Health Science, University of Free State, Bloemfontein 9300, South Africa.
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7
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Prakash R, Negi SS, Bhargava A, Sharma K, Jagzape T, Wasnik P. Evaluation of an in-house PCR for diagnosing scrub typhus along with a preliminary study of genotypic characterization of Orientia tsutshugamushi circulating in Chhattisgarh: A prospective clinico-microbiological study. Indian J Med Microbiol 2022; 40:510-515. [PMID: 36050139 DOI: 10.1016/j.ijmmb.2022.08.005] [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: 03/10/2022] [Revised: 07/28/2022] [Accepted: 08/03/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE Scrub typhus, caused by Orientia tsutsugamushi (O. tsutsugamushi) present nonspecific clinical features during manifestation of acute undifferentiated febrile illness (AUFI) to render its early diagnosis difficult. Accordingly, this study was undertaken to assess an in-house groEL PCR versus IgM ELISA for the diagnosis of scrub typhus and to genotypically characterise the randomly selected scrub typhus positive cases. METHODS Blood samples, collected from two hundred twenty one (221) AUFI cases were subjected to groEL PCR and IgM ELISA for diagnosis of scrub typhus. Eleven randomly selected PCR positive cases were processed for DNA sequencing to determine the genetic diversity of O. tsutsugamushi in Chhattisgarh. RESULTS Scrub typhus prevalence of 35.2% were detected among AUFI cases using both in-house groEL PCR and IgM ELISA. PCR alone showed sensitivity, specificity, positive and negative predictive values of 66.6% (CI: 55.08-76.94), 100% (CI: 90 to 100),100% (CI: 93.15 to 100) and 57.37% (CI: 44.05 to 69.96) while for IgM ELISA, these parameters were 62.8% (CI: 51.13-73.50), 100% (CI: 90 to 100), 100% (CI: 92.75 to 100) and 54.68% (CI: 41.75 to 67.18) respectively. PCR and ELISA could detect scrub typhus in 37.2% and 33.3% cases, when tested alone. groEL PCR detected the O. tsutsugamushi throughout the course of infection. Phylogenetic analysis depicted 5 of 11 positive cases belonged to Kuroki, Japan strain of O. tsutsugamushi, followed by Gilliam and Karp strain in 4 and 2 cases respectively. CONCLUSION Scrub typhus should be considered in differential diagnosis of AUFI. groEL PCR may aid on to IgM ELISA test for optimum laboratory diagnosis of scrub typhus by its implementation especially in seronegative cases. Predominance of Kuroki-like strain followed by Gillian and Karp strains of O. tsutsugamushi in Chhattisgarh confirm variable geographical distribution of O. tsutsugamushi and provide the baseline epidemiological data which will eventually be used to help the researchers for developing better diagnostic tests and vaccine covering the predominant genotypes.
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Affiliation(s)
- Rishika Prakash
- Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, India
| | - Sanjay Singh Negi
- Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, India.
| | - Anudita Bhargava
- Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, India
| | - Kuldeep Sharma
- Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Raipur, India
| | - Tushar Jagzape
- Department of Paediatrics, All India Institute of Medical Sciences (AIIMS), Raipur, India
| | - Preetam Wasnik
- Department of General Medicine, All India Institute of Medical Sciences (AIIMS), Raipur, 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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9
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Jang WS, Lim DH, Choe YL, Nam J, Moon KC, Kim C, Choi M, Park I, Park DW, Lim CS. Developing a multiplex loop-mediated isothermal amplification assay (LAMP) to determine severe fever with thrombocytopenia syndrome (SFTS) and scrub typhus. PLoS One 2022; 17:e0262302. [PMID: 35171943 PMCID: PMC8849512 DOI: 10.1371/journal.pone.0262302] [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: 07/22/2021] [Accepted: 12/21/2021] [Indexed: 11/19/2022] Open
Abstract
Severe fever with thrombocytopenia syndrome (SFTS) and scrub typhus are endemic zoonotic diseases that pose significant public health threats in East Asia. As these two diseases share common clinical features, as well as overlapping disease regions, it is difficult to differentiate between SFTS and scrub typhus. A multiplex reverse-transcription loop‑mediated isothermal amplification (RT-LAMP) assay was developed to detect large segments and GroES genes for SFTS virus (SFTSV) and Orientia tsutsugamushi (OT). The performance of the RT-LAMP assay was compared and evaluated with those of commercial PowerChek™ SFTSV real-time PCR and LiliF™ TSUTSU nested PCR for 23 SFTS and 12 scrub typhus clinical samples, respectively. The multiplex SFTSV/OT/Internal control (IC) RT-LAMP assay showed comparable sensitivity (91.3%) with that of commercial PowerChek™ SFTSV Real-time PCR (95.6%) and higher sensitivity (91.6%) than that of LiliF™ TSUTSU nested PCR (75%). In addition, the multiplex SFTSV/OT RT-LAMP assay showed 100% specificity and no cross-reactivity for blood from uninfected healthy patients and samples from patients infected with other fever viruses. Thus, the multiplex SFTSV/OT/IC RT-LAMP assay could serve as a useful point-of-care molecular diagnostic test for SFTS and scrub typhus.
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Affiliation(s)
- Woong Sik Jang
- Emergency Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Da Hye Lim
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Young Lan Choe
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Jeonghun Nam
- Department of Song‐do Bio Engineering, Incheon Jaeneung University, Incheon, Korea
- Artificial Intelligence (AI)‐Bio Research Center, Incheon Jaeneung University, Incheon, Korea
| | - Kyung Chul Moon
- Emergency Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Chaewon Kim
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Minkyeong Choi
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Insu Park
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Dae Won Park
- Division of Infectious Diseases, Department of Internal Medicine, Korea University Ansan Hospital, Ansan-si, Gyeonggi-do, Republic of Korea
| | - Chae Seung Lim
- Departments of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, Korea
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Tantibhedhyangkul W, Matamnan S, Longkunan A, Boonwong C, Khowawisetsut L. Endothelial Activation in Orientia tsutsugamushi Infection Is Mediated by Cytokine Secretion From Infected Monocytes. Front Cell Infect Microbiol 2021; 11:683017. [PMID: 34368012 PMCID: PMC8340038 DOI: 10.3389/fcimb.2021.683017] [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: 03/19/2021] [Accepted: 07/06/2021] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus, caused by Orientia tsutsugamushi, is a common systemic infection in Asia. Delay in diagnosis and treatment can lead to vasculitis in the visceral organs and other complications. The mechanisms that drive endothelial activation and the inflammatory response in O. tsutsugamushi infection remain unknown. In addition, the interaction between monocytes and endothelial cells is still unclear. Here we demonstrate that O. tsutsugamushi-infected human dermal microvascular endothelial cells produced moderate levels of chemokines and low levels of IL-6 and IFN-β, but not TNF or IL-1β. Recombinant TNF and cytokine-rich supernatants from infected monocytes markedly enhanced chemokine production in infected endothelial cells. We also show that TNF and monocyte supernatants, but not O. tsutsugamushi infection of endothelial cells per se, upregulated the endothelial cell surface expression of ICAM-1, E-selectin, and tissue factor. This finding was consistent with the inability of O. tsutsugamushi to induce cytokine secretion from endothelial cells. The upregulation of surface molecules after stimulation with monocyte supernatants was significantly reduced by neutralizing anti-TNF antibodies. These results suggest that endothelial cell activation and response are mainly mediated by inflammatory cytokines secreted from monocytes.
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Affiliation(s)
- Wiwit Tantibhedhyangkul
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sutthicha Matamnan
- Graduate Program in Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Research Division, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Asma Longkunan
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Graduate Program in Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chawikan Boonwong
- Research Division, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Ladawan Khowawisetsut
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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11
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Lu CT, Wang LS, Hsueh PR. Scrub typhus and antibiotic-resistant Orientia tsutsugamushi. Expert Rev Anti Infect Ther 2021; 19:1519-1527. [PMID: 34109905 DOI: 10.1080/14787210.2021.1941869] [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] [Indexed: 12/23/2022]
Abstract
Introduction: Scrub typhus is one of the most underdiagnosed and under-reported febrile illnesses requiring hospitalization, mainly occurring in Southeast and East Asia and the Pacific Islands, in an area referred to as the 'Tsutsugamushi Triangle.' Scrub typhus is a zoonotic rickettsial disease that is transmitted to humans by trombiculid mites.Areas covered: A MEDLINE/PubMed search of the available literature was performed to describe the role of antibiotic-resistant scrub typhus in therapy failure.Expert opinion: Scrub typhus is characterized by an eschar that may appear 2-3 days before sudden-onset fever with chills, headache, backache, myalgia, profuse sweating, vomiting, and enlarged lymph nodes. A macular or maculopapular skin rash can develop within 3-8 days after the onset of fever. Various antibiotics, such as chloramphenicol, tetracycline, doxycycline, macrolides, quinolones, and rifampicin, have been used to treat scrub typhus. Resistance to tetracycline has been proposed to underlie delayed clinical improvement since 1996, but recent reports have questioned the existence of doxycycline resistance. Nevertheless, the existence and importance of antibiotic-resistant scrub typhus remain uncertain and require further study.
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Affiliation(s)
- Chin-Te Lu
- Department of Infectious Diseases, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Yilan, Taiwan
| | - Lih-Shinn Wang
- Division of Infectious Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
| | - Po-Ren Hsueh
- Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.,Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
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12
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Ernieenor FCL, NorJaiza MJ, Fadillah A, Canedy J, Mariana A. Screening and genotyping of Orientia tsutsugamushi from field-collected on-host chiggers (Acari: Prostigmata) recovered from a positive scrub typhus locality in Kelantan, Malaysia. EXPERIMENTAL & APPLIED ACAROLOGY 2021; 84:171-182. [PMID: 33826009 DOI: 10.1007/s10493-021-00609-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Orientia tsutsugamushi is the causative agent of scrub typhus vectored by larval stages of trombiculid mites (chiggers) that occur in most tropical regions of Southeast Asia. A total of 242 chiggers extracted from eight small mammals captured from a positive scrub typhus locality in Kelantan, Malaysia, were screened for the presence of O. tsutsugamushi. The chiggers were grouped in 16 pools for extraction of DNA prior to screening of O. tsutsugamushi based on the nucleotide sequence of 56-kDa type specific antigen (TSA) gene using nested polymerase chain reaction. Two species of on-host chiggers were identified, the one, Leptotrombidium deliense, much more dominant (94.8%) than the other, Ascoshoengastia sp. (5.2%). The pathogen was detected in two pools (12.5%) of L. deliense recovered from Rattus rattus and Tupaia sp. The 56-kDa TSA gene sequence analysis revealed the O. tsutsugamushi harboured in those chiggers were Karp prototype strain with high similarity (99.3%). Findings of this study strongly supported the existence of scrub typhus infections in certain parts of Malaysia which agrees with previous local reports. Moreover, this study highlighted the pressing need of a large-scale close observation of O. tsutsugamushi DNA sequences from chiggers that can probably be collected from other positive scrub typhus localities to precisely provide the distribution and prevalence of this zoonotic pathogen.
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Affiliation(s)
- F C L Ernieenor
- Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Acarology Unit, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia.
| | - M J NorJaiza
- Disease Control Division, Entomology and Pest Unit, Kelantan State Health Department, Ministry of Health Malaysia, Jalan Mahmood, 15200, Kota Bharu, Kelantan, Malaysia
| | - A Fadillah
- Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Acarology Unit, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
| | - J Canedy
- Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Acarology Unit, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
| | - A Mariana
- Infectious Diseases Research Centre, Institute for Medical Research (IMR), National Institutes of Health, Ministry of Health Malaysia, Acarology Unit, Jalan Setia Murni U13/52, Seksyen U13, Setia Alam, 40170, Shah Alam, Selangor, Malaysia
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13
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Watanabe Y, Mashimo S, Ichige H, Nagata H, Kojima M. Scrub typhus mimicking the clinical course of infectious mononucleosis: a case report. J Rural Med 2021; 16:62-66. [PMID: 33442438 PMCID: PMC7788302 DOI: 10.2185/jrm.2020-037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/11/2020] [Indexed: 01/22/2023] Open
Abstract
Objective: Scrub typhus is a relatively common life-threating disease; its
symptoms are non-specific and similar to those of other viral infections. Therefore, scrub
typhus might be underdiagnosed. Patient: Herein, we report a patient with scrub typhus whose clinical course
mimicked that of infectious mononucleosis. A 63-year-old male patient with hypertension
presented to our hospital complaining of symptoms including prolonged fever, pharyngeal
discomfort, and a mild headache. He showed the appearance of a rash after amoxicillin
administration. At the same time, he did not show a crusted rash on his body surface. Results: After a comprehensive examination, Epstein-Barr virus and
cytomegalovirus infections were ruled out. We suspected that this patient suffered from
scrub typhus on the basis of his usual lifestyle. Finally, polymerase chain reaction
analysis showed a positive result for deoxyribonucleic acid of Orientia
tsutsugamushi in his blood sample. Fortunately, he recovered naturally with
only supportive treatment during his hospitalization. Conclusion: We should observe and monitor patients with infectious
mononucleosis-like symptoms and emphasize the importance of a clinical interview.
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Affiliation(s)
- Yusuke Watanabe
- Department of Internal Medicine, Hitachiomiya Saiseikai Hospital, Japan
| | - Shouta Mashimo
- Department of Internal Medicine, Hitachiomiya Saiseikai Hospital, Japan
| | - Hiroyuki Ichige
- Department of Internal Medicine, Hitachiomiya Saiseikai Hospital, Japan
| | - Hiroyuki Nagata
- Department of Internal Medicine, Hitachiomiya Saiseikai Hospital, Japan
| | - Masayuki Kojima
- Department of Surgery, Hitachiomiya Saiseikai Hospital, Japan
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14
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Kannan K, John R, Kundu D, Dayanand D, Abhilash KPP, Mathuram AJ, Zachariah A, Sathyendra S, Hansdak SG, Abraham OC, Gunasekaran K, Iyadurai R, Abraham AM, Prakash JAJ, Yesudhason BL, Veeraraghavan B, Kavitha ML, Jose LR, Sumana MN, Saravu K, Varghese GM. Performance of molecular and serologic tests for the diagnosis of scrub typhus. PLoS Negl Trop Dis 2020; 14:e0008747. [PMID: 33180784 PMCID: PMC7660479 DOI: 10.1371/journal.pntd.0008747] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/25/2020] [Indexed: 01/19/2023] Open
Abstract
Diagnosis of scrub typhus, caused by the bacterium Orientia tsutsugamushi, is challenging because of the overlap of its non-specific symptoms with other infections coupled with the lack of sufficient data on the performance of diagnostic tests. Early diagnosis of scrub typhus is crucial to improve outcomes and this study evaluates the diagnostic performance of various tests. The present study aims at assessing the accuracy of various rapid diagnostic tests, serologic tests, and nucleic acid amplification methods on well-characterized patient samples. Adult patients with acute febrile illness and manifestations suggestive of scrub typhus confirmed by positive PCR in the blood, eschar or tissue were characterized as cases. Patients with acute febrile illness and a confirmed alternate etiology such as culture-confirmed typhoid, smear/PCR positive for malaria, PCR/NS1 antigen positive for dengue, PCR positive for influenza, PCR/MAT positive for leptospirosis, PCR positive for spotted fever were characterized as controls with other infections. The healthy controls consisted of subjects from the same geographic region. We performed the following tests on blood samples for scrub typhus and calculated the sensitivity, specificity, positive predictive value, and negative predictive value: (1) Quantitative real time PCR using 47kDa gene (qPCR); (2) Conventional PCR using 56kDa gene (cPCR); (3) Loop-mediated isothermal amplification assay (LAMP assay); (4) Immunofluorescence assay (IFA); (5) Enzyme-linked immunosorbent assay (ELISA); (6) Weil-Felix test(WF test); and (7) Immunochromatographic Rapid Diagnostic Test (RDT).Among the 316 participants, 158 had confirmed scrub typhus (cases) and 158 were controls. ELISA and RDT detecting Orientia tsutsugamushi specific IgM antibodies had excellent discriminative potential with sensitivities and specificities of 92%, 94% and 92%, 92% respectively. The sensitivity and specificity of IFA were found to be 95% and 74% respectively. IgM serology had a false positivity rate of 8% with other acute febrile illnesses such as dengue, leptospirosis and spotted fever due to the nonspecific binding of the pentavalent IgM. LAMP assay had 91.7% sensitivity and 77.2% specificity while qPCR provided excellent sensitivity (97%) and perfect specificity. In conclusion, ELISA and RDT detecting Orientia tsutsugamushi specific IgM antibodies have excellent sensitivity and specificity while the accuracy of IFA is suboptimal for the diagnosis of scrub typhus. Given its perfect specificity and superior sensitivity, qPCR is preferred for diagnostic confirmation in reference laboratories particularly for diagnosis of early disease with less than 7 days duration. This study provides a comprehensive evaluation of all currently available diagnostic tests for scrub typhus.
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Affiliation(s)
- Kavitha Kannan
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | - Rebecca John
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | - Debasree Kundu
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | - Divya Dayanand
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Alice Joan Mathuram
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Anand Zachariah
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sowmya Sathyendra
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Samuel G. Hansdak
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - O. C. Abraham
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Karthik Gunasekaran
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Ramya Iyadurai
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Asha M. Abraham
- Department of Clinical Virology, Christian Medical College, Vellore, Tamil Nadu, India
| | | | | | - Balaji Veeraraghavan
- Department of Microbiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - M. L. Kavitha
- Department of Haematology, Christian Medical College, Vellore, Tamil Nadu, India
| | | | | | - Kavitha Saravu
- Department of Infectious Diseases, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Karnataka, India
| | - George M. Varghese
- Department of Infectious Diseases, Christian Medical College, Vellore, Tamil Nadu, India
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15
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Establishment of Recombinase Polymerase Amplification assay for rapid and sensitive detection of Orientia tsutsugamushi in Southeast Asia. Acta Trop 2020; 210:105541. [PMID: 32492397 DOI: 10.1016/j.actatropica.2020.105541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/05/2020] [Accepted: 05/13/2020] [Indexed: 11/20/2022]
Abstract
Scrub typhus, caused by Orientia tsutsugamushi, is a common fever in parts of Southern and Southeast Asia. As delayed diagnosis of scrub typhus leads to inappropriate treatment and high mortality rates, of up to 70%, sensitive and rapid detection of O. tsutsugamushi is required for timely and appropriate treatment. Molecular assays, such as PCR and real-time PCR, have been shown to be more sensitive than conventional immunoassay, however, they are only available in centralized laboratories. In contrast to PCR assays, Recombinase Polymerase Amplification (RPA) is conducted under a constant temperature ranging from 24°C to 45°C. Therefore, this technology is very promising for nucleic acid testing in the field, and in resource-limited areas. An RPA assay for the detection of O. tsutsugamushi based on the target gene encoding for the 47 kDa outer membrane protein has been reported, but the primer and probe sequences of this assay are suboptimal for detection of the majority of recently published sequences of O. tsutsugamushi isolates from Southeast Asia. We have established a real-time RPA assay with primer and probe sequences that are optimized for most Southeast Asia's isolates of O. tsutsugamushi. As a result, the new RPA assay showed better performance than the previous assay in detecting O. tsutsugamushi in clinical samples of scrub typhus cases found in Vietnam. The specificity of RPA assay was also evaluated using genomic DNA from microorganisms commonly encountered in the differential diagnosis of scrub typhus, and blood samples from healthy controls and O. tsutsugamushi negative confirmed cases.
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16
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Kala D, Gupta S, Nagraik R, Verma V, Thakur A, Kaushal A. Diagnosis of scrub typhus: recent advancements and challenges. 3 Biotech 2020; 10:396. [PMID: 32834918 PMCID: PMC7431554 DOI: 10.1007/s13205-020-02389-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Scrub typhus is a mite-borne, acute febrile illness caused by the bacterium Orientia tsutsugamushi. It is a re-emerging infectious disease of the tsutsugamushi triangle. Scrub typhus is transmitted through bites of contaminated chiggers (larval stage). Diagnosis of scrub typhus is challenging as its symptoms mimic with other acute febrile illnesses. Several methods are effectual for diagnosis of scrub typhus that includes enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), immunochromatographic test (ICT), Weil-Felix, polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP). Weil-Felix test was initially used for the diagnosis of scrub typhus in underdeveloped countries but not preferred due to a lack of both specificity and sensitivity. Other immuno-based methods like IFA and ELISA are most outrank for detection of scrub typhus due to their higher sensitivity and specificity, but not vigorous to lay bare the infection at early stages and need the convalescent sampling for verification of positive samples. On another deed, PCR based methods becoming acceptable over era due to its dexterity of early-stage diagnosis with higher specificity and sensitivity but lack its applicability in circumstances of scrub typhus due to the variegated genetic makeup of Orientia tsutsugamushi among its serotypes. The present review focused on various detection methods along with their advantages and disadvantages used in the diagnosis of scrub typhus. A comparison between available methods of diagnosis with challenges in the detection of scrub typhus is also summarized.
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Affiliation(s)
- Deepak Kala
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | | | | | | | - Atul Thakur
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
| | - Ankur Kaushal
- Amity Center of Nanotechnology, Amity University, Haryana, 122413 India
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17
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Optimization and Evaluation of a Multiplex Quantitative PCR Assay for Detection of Nucleic Acids in Human Blood Samples from Patients with Spotted Fever Rickettsiosis, Typhus Rickettsiosis, Scrub Typhus, Monocytic Ehrlichiosis, and Granulocytic Anaplasmosis. J Clin Microbiol 2020; 58:JCM.01802-19. [PMID: 32493778 DOI: 10.1128/jcm.01802-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/25/2020] [Indexed: 01/09/2023] Open
Abstract
Spotted fever group rickettsioses (SFGR), typhus group rickettsioses (TGR), scrub typhus (caused by Orientia tsutsugamushi), ehrlichiosis, and anaplasmosis often present as undifferentiated fever but are not treated by agents (penicillins and cephalosporins) typically used for acute febrile illness. Inability to diagnose these infections when the patient is acutely ill leads to excess morbidity and mortality. Failure to confirm these infections retrospectively if a convalescent blood sample is not obtained also impairs epidemiologic and clinical research. We designed a multiplex real-time quantitative PCR (qPCR) assay to detect SFGR, TGR, O. tsutsugamushi, and infections caused by Anaplasma phagocytophilum and Ehrlichia chaffeensis with the ompA, 17-kDa surface antigen gene, tsa56, msp2 (p44), and vlpt gene targets, respectively. Analytical sensitivity was ≥2 copies/μl (linear range, 2 to 2 × 105) and specificity was 100%. Clinical sensitivities for SFGR, TGR, and O. tsutsugamushi were 25%, 20%, and 27%, respectively, and specificities were 98%, 99%, and 100%, respectively. Clinical sensitivities for A. phagocytophilum and E. chaffeensis were 93% and 84%, respectively, and specificities were 99% and 98%, respectively. This multiplex qPCR assay could support early clinical diagnosis and treatment, confirm acute infections in the absence of a convalescent-phase serum sample, and provide the high-throughput testing required to support large clinical and epidemiologic studies. Because replication of SFGR and TGR in endothelial cells results in very low bacteremia, optimal sensitivity of qPCR for these rickettsioses will require use of larger volumes of input DNA, which could be achieved by improved extraction of DNA from blood and/or extraction of DNA from a larger initial volume of blood.
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18
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Ra SH, Kim JY, Cha HH, Kwon JS, Lee HJ, Jeon NY, Kim MJ, Chong YP, Lee SO, Choi SH, Kim YS, Woo JH, Kim SH. Coinfection of Severe Fever with Thrombocytopenia Syndrome and Scrub Typhus in Patients with Tick-Borne Illness. Am J Trop Med Hyg 2020; 101:1259-1262. [PMID: 31549609 DOI: 10.4269/ajtmh.19-0242] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Severe fever with thrombocytopenia syndrome (SFTS) and scrub typhus are the most common tick-borne diseases in South Korea. However, few studies have systematically examined the simultaneous presence of the two diseases. We found that two (4.9%) of 41 patients with suspected and confirmed SFTS had evidence of coinfection with scrub typhus. In addition, two (3.6%) of 55 suspected and confirmed scrub typhus patients were identified to have coinfection with SFTS. Our data suggest that diagnostic evaluation for coinfection in patients with tick-borne illness and empirical doxycycline treatment in patients with SFTS may be warranted in areas endemic for both diseases until coinfection with scrub typhus is ruled out.
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Affiliation(s)
- Sang Hyun Ra
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Ji Yeun Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hye Hee Cha
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Ji-Soo Kwon
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hyun-Jung Lee
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Na Young Jeon
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Min Jae Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong Pil Chong
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Oh Lee
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Ho Choi
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yang Soo Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jun Hee Woo
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sung-Han Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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19
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Phuklia W, Panyanivong P, Sengdetka D, Sonthayanon P, Newton PN, Paris DH, Day NPJ, Dittrich S. Novel high-throughput screening method using quantitative PCR to determine the antimicrobial susceptibility of Orientia tsutsugamushi clinical isolates. J Antimicrob Chemother 2020; 74:74-81. [PMID: 30295746 PMCID: PMC6293087 DOI: 10.1093/jac/dky402] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/05/2018] [Indexed: 01/08/2023] Open
Abstract
Objectives To develop a method to enable the large-scale antimicrobial susceptibility screening of Orientia tsutsugamushi clinical isolates, using one timepoint and one concentration of antibiotics to considerably speed up the time to result. Methods Growth, harvesting, multiplicity of infection (moi) and the day to determine the MICs were optimized using five O. tsutsugamushi reference strains [susceptible (Karp, Kato and Gilliam) and putatively resistant (AFC-3 and AFSC-4)], one clinical isolate (UT76) and one rodent isolate (TA763). Subsequently, the MICs of azithromycin, chloramphenicol and doxycycline for these strains and 51 clinical isolates including AFSC-7 were determined. An optimal concentration was calculated using the epidemiological cut-off value. Results The conditions for O. tsutsugamushi infection, growth and harvesting were determined to be an moi of 100:1 and trypsinization with the peak growth on day 10. The resulting MICs were in line with previously published susceptibility data for all reference strains, except for Karp and AFSC-4, which showed azithromycin MICs of 0.0156 and 0.0313 mg/L, compared with 0.0078 and 0.0156 mg/L, respectively, in previous reports. The MIC of doxycycline for AFC-3 was 0.125 mg/L compared with >4 mg/L in earlier reports. The final single screening concentrations were identified as: azithromycin, 0.125 mg/L; chloramphenicol, 8 mg/L; and doxycycline, 1 mg/L. Conclusions This simplified procedure facilitates the simultaneous screening of 48 isolates for actively monitoring potential resistance of this important fever pathogen, with an 8-fold throughput improvement over early methods. The data do not support the existence of doxycycline- and chloramphenicol-resistant scrub typhus.
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Affiliation(s)
- Weerawat Phuklia
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Phonepasith Panyanivong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Davanh Sengdetka
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Piengchan Sonthayanon
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Paul N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel H Paris
- 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.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - 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
| | - Sabine Dittrich
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,FIND, Malaria & Fever Program, Geneva, Switzerland
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20
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Sharma B, Thille K, Rametta N, Sharma R. Detection of Leptospira spp. using polymerase chain reaction technique from kidney of Rattus norvegicus from Grenada, West Indies. INTERNATIONAL JOURNAL OF ONE HEALTH 2019. [DOI: 10.14202/ijoh.2019.81-85] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aim: This study aimed to find out the prevalence of active infection of Leptospira spp. in Rattus norvegicus from Grenada, West Indies, through polymerase chain reaction (PCR). Materials and Methods: One hundred and forty-nine rats were trapped, anesthetized and their kidneys collected aseptically. DNA was extracted from the kidney tissue of each rat. PCR was performed targeting LipL32 gene. Eighteen PCR-positive amplicons for LipL32 gene segment were purified and sent for direct sequencing to the sequencing facility of MCLAB (South San Francisco, USA). Results of sequencing were read and interpreted. The prevalence of Leptospira spp. in relation to sex and age was also recorded. Results: All amplified sequences were compared to the sequences present in GenBank using basic local alignment search tool (BLAST) from the online website National Center for Biotechnology Information, the results revealed that six samples had similarity to Leptospira interrogans strain 1399/2016 and eight samples had similarity with Leptospira borgpetersenii serovar Hardjo-bovis strain L49. Of 149 kidney samples, only 14 were positive for Leptospira spp. by PCR giving an incidence of 9.3%. There was no significant difference found in relation to sex and age. Conclusion: This is the first report confirming active infection of Leptospira spp. in Rattus norvegicus in Grenada using PCR. The presence of active infection in rats can be considered as high risk for humans. Further research to understand the epidemiology of leptospirosis in Grenada is suggested.
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Affiliation(s)
- Bhumika Sharma
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, Grenada, West Indies
| | - Katelyn Thille
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, Grenada, West Indies
| | - Nia Rametta
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, Grenada, West Indies
| | - Ravindra Sharma
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, Grenada, West Indies
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21
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Tantibhedhyangkul W, Wongsawat E, Matamnan S, Inthasin N, Sueasuay J, Suputtamongkol Y. Anti-Mycoplasma Activity of Daptomycin and Its Use for Mycoplasma Elimination in Cell Cultures of Rickettsiae. Antibiotics (Basel) 2019; 8:antibiotics8030123. [PMID: 31438510 PMCID: PMC6784056 DOI: 10.3390/antibiotics8030123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 12/24/2022] Open
Abstract
Mycoplasma contamination detrimentally affects cellular functions and the growth of intracellular pathogens in cell cultures. Although several mycoplasmacidal agents are commercially available for sterile cell cultures, they are not applicable to rickettsia-infected cells. In our attempt to find an anti-mycoplasma drug for contaminated rickettsial cultures, we determined the susceptibilities of three common Mycoplasma species to daptomycin. Mycoplasma orale and M. arginini showed low-level resistance to daptomycin (minimum inhibitory concentration, MIC = 2 mg/L), whereas M. hyorhinis was high-level resistant (MIC = 32 mg/L). However, some Mycoplasma isolates developed higher resistance to daptomycin after failed treatments with inadequate doses or durations. An aminoglycoside (gentamicin) was still active against M. hyorhinis and could be used in Orientia cultures. For complete eradication of mycoplasmas in Rickettsia cultures, we recommend a 3-week treatment with daptomycin at 256 mg/L. In contaminated Orientia cultures, daptomycin at 32 mg/L was effective in eradicating M. orale, whereas either gentamicin or amikacin (100 mg/L) was effective in eradicating M. hyorhinis. Unlike each drug alone, the combinations of daptomycin plus clindamycin and/or quinupristin/dalfopristin proved effective in eradicating M. hyorhinis. In summary, our study demonstrated the in vitro anti-mycoplasma activity of daptomycin and its application as a new mycoplasma decontamination method for Rickettsia and Orientia cultures.
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Affiliation(s)
- Wiwit Tantibhedhyangkul
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
| | - Ekkarat Wongsawat
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Sutthicha Matamnan
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Naharuthai Inthasin
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jintapa Sueasuay
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Yupin Suputtamongkol
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
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22
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Lee SH, Hwang J, Kim K, Jeon J, Lee S, Ko J, Lee J, Kang M, Chung DR, Choo J. Quantitative Serodiagnosis of Scrub Typhus Using Surface-Enhanced Raman Scattering-Based Lateral Flow Assay Platforms. Anal Chem 2019; 91:12275-12282. [PMID: 31356055 DOI: 10.1021/acs.analchem.9b02363] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A surface-enhanced Raman scattering-based lateral flow assay (SERS-LFA) technique has been developed for the rapid and accurate diagnosis of scrub typhus. Lateral flow kits for the detection of O. tsutsugamushi IgG (scrub typhus biomarker) were fabricated, and the calibration curve for various standard clinical sera concentrations were obtained by Raman measurements. The clinical sera titer values were determined by fitting the Raman data to the calibration curve. To assess the clinical feasibility of the proposed method, SERS-LFA assays were performed on 40 clinical samples. The results showed good agreement with those of the standard indirect immunofluorescence assay (IFA) method. SERS-LFA has many advantages over IFA including the less sample volume, simpler assay steps, shorter assay time, more systematic quantitative analysis, and longer assay lifetime. As SERS strips can be easily integrated with a miniaturized Raman spectrophotometer, field serodiagnosis is also more feasible.
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Affiliation(s)
- See Hi Lee
- Department of Chemistry , Chung-Ang University , Seoul 06974 , South Korea
| | | | - Kihyun Kim
- Department of Chemistry , Chung-Ang University , Seoul 06974 , South Korea
| | - Jinhyeok Jeon
- Department of Bionano Technology , Hanyang University , Ansan 15588 , South Korea
| | | | - Juhui Ko
- SG Medical, Inc. , Seoul 05548 , South Korea
| | - Jichul Lee
- SG Medical, Inc. , Seoul 05548 , South Korea
| | - Minhee Kang
- Biomedical Engineering Research Centre, Smart Healthcare Research Institute, Samsung Medical Centre , Sungkyunkwan University School of Medicine , Seoul 06351 , South Korea.,Department of Medical Device Management and Research, Samsung Advanced Institute for Health Sciences & Technology (SAIHST) , Sungkyunkwan University , Seoul 06351 , South Korea
| | - Doo Ryeon Chung
- Division of Infectious Diseases, Department of Internal Medicine, Samsung Medical Centre , Sungkyunkwan University School of Medicine , Seoul 06351 , South Korea.,Centre for Infection Prevention and Control , Samsung Medical Centre , Seoul 06351 , South Korea
| | - Jaebum Choo
- Department of Chemistry , Chung-Ang University , Seoul 06974 , South Korea
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23
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Chao CC, Belinskaya T, Zhang Z, Jiang L, Ching WM. Assessment of a Sensitive qPCR Assay Targeting a Multiple-Copy Gene to Detect Orientia tsutsugamushi DNA. Trop Med Infect Dis 2019; 4:tropicalmed4030113. [PMID: 31370347 PMCID: PMC6789807 DOI: 10.3390/tropicalmed4030113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/02/2022] Open
Abstract
Scrub typhus is caused by an obligated intracellular organism, Orientia tsutsugamushi (Orientia). The disease was traditionally thought to be limited in the tsutsugamushi triangle. Recently, scrub typhus has been confirmed in areas outside the triangle. Serological diagnosis of scrub typhus relies on indirect immunofluorescence assay (IFA). Molecular assays such as PCR, qPCR, loop-mediated isothermal amplification, and recombinase polymerase amplification are often targeting a single copy gene. These assays are sensitive and specific, yet they are not broadly used in clinical settings possibly due to low circulating Orientia in blood. In this study, we compared qPCR results using a multiple copy (traD) gene with those using a single copy (47 kDa) gene to assess the improvement of sensitivity and limit of detection. Our results demonstrate that the qPCR using the traD gene provides superior sensitivity in 15 Orientia strains. The limit of detection is below single Orientia genome equivalent and the assay retains specificity with excessive DNA from mouse, chiggers and human. The clinical utility was evaluated using confirmed scrub typhus positive and negative samples. The results show 100% sensitivity and specificity in these samples suggesting that the traD gene qPCR may be useful for clinical diagnosis of Orientia infection.
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Affiliation(s)
- Chien-Chung Chao
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA.
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Tatyana Belinskaya
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Zhiwen Zhang
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Le Jiang
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Wei-Mei Ching
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Center, Silver Spring, MD 20910, USA
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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24
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Sea-liang N, Sereemaspun A, Patarakul K, Gaywee J, Rodkvamtook W, Srisawat N, Wacharaplusadee S, Hemachudha T. Development of multiplex PCR for neglected infectious diseases. PLoS Negl Trop Dis 2019; 13:e0007440. [PMID: 31283768 PMCID: PMC6613674 DOI: 10.1371/journal.pntd.0007440] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 05/06/2019] [Indexed: 01/28/2023] Open
Abstract
Scrub typhus, murine typhus, and leptospirosis are widely neglected infectious diseases caused by Orientia tsutsugamushi, Rickettsia typhi, and pathogenic Leptospira spp., respectively. Patients usually present with non-specific symptoms and therefore are commonly diagnosed with acute undifferentiated febrile illness. Consequently, patients face delayed treatment and increased mortality. Antibody-based serological test currently used as gold standard has limitations due to insufficient antibody titers, especially in the early phase of infection. In this study, we aimed to develop multiplex PCR to combine 3 primer pairs that target specific genes encoding 56-kDa TSA of O. tsutsugamushi, 17-kDa antigen of R. typhi, and LipL32 of L. Interrogans and evaluate its performance in comparison to the standard serological tests. Using EDTA blood samples of known patients, the sensitivity and specificity of our multiplex PCR was 100% and 70%, respectively. In addition, the assay was able to diagnose the co-infection of scrub typhus and leptospirosis. The assay may be useful in identifying causative agents during the early phase of these diseases, enabling prompt and appropriate treatment. Scrub typhus, murine typhus, and leptospirosis are diagnosed as acute undifferentiated febrile illness. Diagnostic tests for these diseases depend on antibody detection. However, antibody detection is still limited by its tendency to return negative results during the early phase of aforementioned diseases. In this study, a novel multiplex PCR has been developed for detecting Orientia tsutsugamushi, Rickettsia typhi, and Leptospira interrogans that are simultaneously amplified in a single tube. The results have shown that multiplex PCR could be used as a diagnostic tool for detecting bacteria during the early phase of scrub typhus, murine typhus, and leptospirosis, allowing for administration of appropriate treatment.
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Affiliation(s)
- Nutchanart Sea-liang
- Nanomedicine Research Unit, Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Amornpun Sereemaspun
- Nanomedicine Research Unit, Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
- * E-mail:
| | - Kanitha Patarakul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jariyanart Gaywee
- Armed Forces Research Institute of Medical Science, Royal Thai Army, Bangkok, Thailand
| | - Wuttikon Rodkvamtook
- Armed Forces Research Institute of Medical Science, Royal Thai Army, Bangkok, Thailand
| | - Nattachai Srisawat
- Nephrology Unit, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Supaporn Wacharaplusadee
- Thai Red Cross Emerging Infectious Diseases-Health Science Centre, World Health Organization Collaborating Centre for Research and Training on Viral Zoonoses, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Thiravat Hemachudha
- Thai Red Cross Emerging Infectious Diseases-Health Science Centre, World Health Organization Collaborating Centre for Research and Training on Viral Zoonoses, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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25
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Evans SM, Adcox HE, VieBrock L, Green RS, Luce-Fedrow A, Chattopadhyay S, Jiang J, Marconi RT, Paris D, Richards AL, Carlyon JA. Outer Membrane Protein A Conservation among Orientia tsutsugamushi Isolates Suggests Its Potential as a Protective Antigen and Diagnostic Target. Trop Med Infect Dis 2018; 3:E63. [PMID: 30274459 PMCID: PMC6073748 DOI: 10.3390/tropicalmed3020063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/31/2018] [Accepted: 06/04/2018] [Indexed: 01/28/2023] Open
Abstract
Scrub typhus threatens one billion people in the Asia-Pacific area and cases have emerged outside this region. It is caused by infection with any of the multitude of strains of the bacterium Orientia tsutsugamushi. A vaccine that affords heterologous protection and a commercially-available molecular diagnostic assay are lacking. Herein, we determined that the nucleotide and translated amino acid sequences of outer membrane protein A (OmpA) are highly conserved among 51 O. tsutsugamushi isolates. Molecular modeling revealed the predicted tertiary structure of O. tsutsugamushi OmpA to be very similar to that of the phylogenetically-related pathogen, Anaplasma phagocytophilum, including the location of a helix that contains residues functionally essential for A. phagocytophilum infection. PCR primers were developed that amplified ompA DNA from all O. tsutsugamushi strains, but not from negative control bacteria. Using these primers in quantitative PCR enabled sensitive detection and quantitation of O. tsutsugamushi ompA DNA from organs and blood of mice that had been experimentally infected with the Karp or Gilliam strains. The high degree of OmpA conservation among O. tsutsugamushi strains evidences its potential to serve as a molecular diagnostic target and justifies its consideration as a candidate for developing a broadly-protective scrub typhus vaccine.
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Affiliation(s)
- Sean M Evans
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
| | - Haley E Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
| | - Lauren VieBrock
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
| | - Ryan S Green
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
| | - Alison Luce-Fedrow
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
- Department of Biology, Shippensburg University, Shippensburg, PA 17257, USA.
| | - Suschsmita Chattopadhyay
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Ju Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
| | - Richard T Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
| | - Daniel Paris
- Department of Medicine, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland.
| | - Allen L Richards
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA.
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Jason A Carlyon
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, VA 23298, USA.
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26
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Kim JY, Koo B, Jin CE, Kim MC, Chong YP, Lee SO, Choi SH, Kim YS, Woo JH, Shin Y, Kim SH. Rapid Diagnosis of Tick-Borne Illnesses by Use of One-Step Isothermal Nucleic Acid Amplification and Bio-Optical Sensor Detection. Clin Chem 2017; 64:556-565. [PMID: 29208659 DOI: 10.1373/clinchem.2017.280230] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/30/2017] [Indexed: 01/05/2023]
Abstract
BACKGROUND Scrub typhus and severe fever with thrombocytopenia syndrome (SFTS) are the most common tick-borne illnesses in South Korea. Early differentiation of SFTS from scrub typhus in emergency departments is essential but difficult because of their overlapping epidemiology, shared risk factors, and similar clinical manifestations. METHODS We compared the diagnostic performance of one-step isothermal nucleic acid amplification with bio-optical sensor detection (iNAD) under isothermal conditions, which is rapid (20-30 min), with that of real-time PCR, in patients with a confirmed tick-borne illness. Fifteen patients with confirmed SFTS who provided a total of 15 initial blood samples and 5 follow-up blood samples, and 21 patients with confirmed scrub typhus, were evaluated. RESULTS The clinical sensitivity of iNAD (100%; 95% CI, 83-100) for SFTS was significantly higher than that of real-time PCR (75%; 95% CI, 51-91; P = 0.047), while its clinical specificity (86%; 95% CI, 65-97) was similar to that of real-time PCR (95%; 95% CI, 77-99; P = 0.61). The clinical sensitivity of iNAD for scrub typhus (100%; 95% CI, 81-100) was significantly higher than that of real-time PCR for scrub typhus (67%; 95% CI, 43-85; P = 0.009), while its clinical specificity (90%; 95% CI, 67-98) was similar to that of real-time PCR (95%; 95% CI, 73-100; P > 0.99). CONCLUSIONS iNAD is a valuable, rapid method of detecting SFTS virus and Orientia tsutsugamushi with high clinical sensitivity and specificity.
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Affiliation(s)
- Ji Yeun Kim
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Bonhan Koo
- Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Choong Eun Jin
- Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Min Chul Kim
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong Pil Chong
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Oh Lee
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sang-Ho Choi
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yang Soo Kim
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jun Hee Woo
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong Shin
- Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
| | - Sung-Han Kim
- Departments of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea;
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