Molecular-based study of scrub typhus in Kerala, South India from 2014 to 2021: a laboratory-based study

被引：2
作者：
Seetha D. [1 ,2 ]
Nori S.R.C. [3 ,4 ]
Nair R.R. [2 ]
机构：
[1] Laboratory Medicine and Molecular Diagnostics, Rajiv Gandhi Centre for Biotechnology (RGCB), Thiruvananthapuram
[2] Teagasc Food Research Centre, Fermoy, Co. Cork, Moorepark
[3] School of Microbiology, University College Cork, Cork
来源：
Comparative Clinical Pathology | 2023年 / 32卷 / 3期
关键词：
IgM antibody enzyme-linked immunosorbent assay; Nested polymerase chain reaction; Orientia tsutsugamushi; Sanger sequencing; Scrub typhus;
D O I：
10.1007/s00580-023-03443-8
中图分类号：
学科分类号：
摘要：
Scrub typhus (ST) is a neglected acute, febrile, infectious disease caused by the intracellular parasite Orientia tsutsugamushi, a gram-negative coccobacillus of the family Rickettsiaceae. Early and precise diagnosis is crucial to reduce the risk of developing disease complications. However, IgM antibody enzyme-linked immunosorbent assay (IgM ELISA) and indirect immunofluorescence assay (IFA) remain essential for diagnosis. However, it could be more helpful for early diagnosis due to the need for uniformity of approach in the diagnostic accuracy studies to determine appropriate ELISA cut-offs for various geographic locations. Hence, we aim to study the O. tsutsugamushi type-specific 56 kilodalton (kDa) protein gene using nested PCR (nPCR) and DNA sequence analysis as a molecular marker for early diagnosis. Out of 10,439 suspected cases, 1147/10,439 (11%) patients were positive for IgM ELISA. A total of 1044/10,439 (10%) samples were randomly tested after nPCR and compared with IgM ELISA results and DNA sequence analysis. Using nested PCR and IgM ELISA methods, 13% (134/1044) and 12% (125/1044) of the samples were positive, respectively. The serology method could not replicate the substantial number of positive cases demonstrated by nPCR; therefore, significant mutual exclusivity of the two techniques requires further investigation. Furthermore, our phylogenetic analysis revealed a clustering of isolates with Karp-related strains, providing insight into the transmission dynamics. Therefore, molecular diagnostic methods may aid in the early diagnosis of infection and enable prompt treatment of ST in endemic regions. Our results show that IgM ELISA can provide complete diagnostic advantages in conjunction with nPCR and can be an essential tool for accurate diagnosis. In addition, the DNA sequencing analysis of the samples showed that Karp-related strains were the main strains. Furthermore, research with samples from various regions in combination with the entire genome sequencing of O. tsutsugamushi is required to understand the infection mechanism better and develop robust early detection methods. © 2023, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.
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页码：347 / 356
页数：9
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