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Othman S, Lee PY, Lam JY, Philip N, Azhari NN, Affendy NB, Masri SN, Neela VK, Mohd-Taib FS, Chee HY. A versatile isothermal amplification assay for the detection of leptospires from various sample types. PeerJ 2022; 10:e12850. [PMID: 35291487 PMCID: PMC8918162 DOI: 10.7717/peerj.12850] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/07/2022] [Indexed: 01/10/2023] Open
Abstract
Background Leptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira that affects both humans and animals worldwide. Early detection of the pathogen in humans is crucial for early intervention and control of the progression of the disease to a severe state. It is also vitally important to be able to detect the presence of the pathogen in carrier animals to control the spread of the disease from the environment. Here we developed a simple and rapid loop-mediated isothermal amplification (LAMP) assay targeting the leptospiral secY gene. Results Several reaction conditions of the LAMP reaction were optimized to ensure efficient amplification of the target DNA. The sensitivity of the developed LAMP assay obtained using a pure Leptospira culture was 2 × 104 copies of genomic DNA per reaction (equivalent to 0.1 ng) for a 40-minute reaction time. No cross-reactions were observed in the LAMP reaction against a series of non-leptospiral bacteria, indicating a specific reaction. The applicability of the LAMP assay was demonstrated on human blood and urine specimens collected from suspected leptospirosis patients and rat kidney specimens collected from suspected leptospirosis outbreak areas and high-risk areas. The developed LAMP assay demonstrated a higher detection rate for leptospiral DNA compared with the polymerase chain reaction (PCR) assay, possibly due to the presence of inhibitory substances, especially in rat kidney specimens, to which the PCR method is more susceptible. The present findings also highlight the importance of urine sample collection from patients for routine monitoring of the disease. Conclusions In short, the developed LAMP assay can serve as a feasible alternative tool for the diagnosis of leptospirosis and be used for epidemiological and environmental surveillance of the disease, considering its robustness, rapidity, sensitivity, and specificity, as demonstrated in this study.
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Affiliation(s)
- Shuhaidah Othman
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Pui-Yuei Lee
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Jia-Yong Lam
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Noraini Philip
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Nurul Natasya Azhari
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Norliza Bahtiar Affendy
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Siti Norbaya Masri
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Vasantha Kumari Neela
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Farah Shafawati Mohd-Taib
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Hui-Yee Chee
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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Macaluso G, Torina A, Blanda V, Guercio A, Lastra A, Giacchino I, D’Agostino R, Sciacca C, D’Incau M, Bertasio C, Grippi F. Leptospira in Slaughtered Fattening Pigs in Southern Italy: Serological Survey and Molecular Typing. Animals (Basel) 2022; 12:ani12050585. [PMID: 35268152 PMCID: PMC8909543 DOI: 10.3390/ani12050585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/15/2022] [Accepted: 02/21/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary In this study, serological and molecular assays in 55 pigs in Sicily were conducted in order to investigate Leptospira spp. prevalence and to carry out strain characterization. A seropositivity rate of 16.4% was determined; 3.64% of kidney samples tested positive for pathogenic Leptospiral DNA. Obtained data showed that Leptospira infection is common among pigs in southern Italy, confirming the importance of Leptospiral infection in pigs and reaffirming the potential role of these animals as a source of infection for humans (occupational risk) and other animals. Our study delivers a comprehensive overview based on up-to-date data to deepen the knowledge of swine leptospiral infections, characterize new potential emerging strains, and reinforce control measures able to reduce the infection risk in swine herds. Abstract Leptospirosis is a re-emerging zoonosis of worldwide significance; a wide spectrum of wild and domestic animal species act as natural or accidental hosts. Swine can act as maintenance or accidental hosts of pathogenic Leptospira spp. This study aimed at investigation of Leptospira spp. prevalence and diversity in slaughtered pigs in southern Italy (Sicily). In total, 55 samples of kidneys and blood were collected. Microscopic agglutination test and real-time PCR were performed to detect pathogenic and intermediately pathogenic Leptospira. Partial rpoB gene sequencing and multi-locus sequence typing (MLST) were performed to characterize Leptospira species. The analysis showed a seropositivity rate of 16.4%, with Australis representing the most frequently identified serogroup (63.64%); Pomona and Sejroe were detected with a prevalence of 27.27% and 9.09%, respectively. Pathogenic Leptospiral DNA was detected in 2 kidney samples (3.64%). Leptospira were identified through MLST as L. borgpetersenii serovar Tarassovi (serogroup Tarassovi). Obtained data confirmed the presence of Leptospira infection among pigs in southern Italy, suggesting that management of these animals may be considered an occupational risk for humans.
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Affiliation(s)
- Giusi Macaluso
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Alessandra Torina
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Valeria Blanda
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
- Correspondence: ; Tel.: +39-09-1656-5235
| | - Annalisa Guercio
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Antonio Lastra
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Ilenia Giacchino
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Rosalia D’Agostino
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Carmela Sciacca
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
| | - Mario D’Incau
- Centro di Referenza Nazionale per la Leptospirosi, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna “Bruno Ubertini”, 25124 Brescia, Italy; (M.D.); (C.B.)
| | - Cristina Bertasio
- Centro di Referenza Nazionale per la Leptospirosi, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna “Bruno Ubertini”, 25124 Brescia, Italy; (M.D.); (C.B.)
| | - Francesca Grippi
- Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, 90129 Palermo, Italy; (G.M.); (A.T.); (A.G.); (A.L.); (I.G.); (R.D.); (C.S.); (F.G.)
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Pereira-Gómez M, Fajardo Á, Echeverría N, López-Tort F, Perbolianachis P, Costábile A, Aldunate F, Moreno P, Moratorio G. Evaluation of SYBR Green real time PCR for detecting SARS-CoV-2 from clinical samples. J Virol Methods 2020; 289:114035. [PMID: 33285190 PMCID: PMC7831559 DOI: 10.1016/j.jviromet.2020.114035] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/06/2020] [Accepted: 12/02/2020] [Indexed: 12/14/2022]
Abstract
The pandemic caused by SARS-CoV-2 has triggered an extraordinary collapse of healthcare systems and hundred thousand of deaths worldwide. Following the declaration of the outbreak as a Public Health Emergency of International Concern by the World Health Organization (WHO) on January 30th, 2020, it has become imperative to develop diagnostic tools to reliably detect the virus in infected patients. Several methods based on real time reverse transcription polymerase chain reaction (RT-qPCR) for the detection of SARS-CoV-2 genomic RNA have been developed. In addition, these methods have been recommended by the WHO for laboratory diagnosis. Since most of these protocols are based on the use of fluorogenic probes and one-step reagents (cDNA synthesis followed by PCR amplification in the same tube), these techniques can be difficult to perform given the limited supply of reagents in low- and middle-income countries. In order to develop an inexpensive SARS-CoV-2 detection protocol using available resources we evaluated the SYBR Green based detection of SARS-CoV-2 to establish a suitable assay. To do so, we adapted one of the WHO recommended TaqMan-based one-step real time PCR protocols (from the University of Hong Kong) to SYBR Green. Our results indicate that SYBR-Green detection of ORF1b-nsp14 target represents a reliable cost-effective alternative to increase the testing capacity.
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Affiliation(s)
- Marianoel Pereira-Gómez
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Álvaro Fajardo
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Natalia Echeverría
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Fernando López-Tort
- Laboratorio de Virología Molecular, Sede Salto, Centro Universitario Regional Litoral Norte, Universidad de la República, Salto, Uruguay
| | - Paula Perbolianachis
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Alicia Costábile
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Fabián Aldunate
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Pilar Moreno
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Gonzalo Moratorio
- Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Laboratorio de Evolución Experimental de Virus, Institut Pasteur de Montevideo, Montevideo, Uruguay.
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A Study of Leptospirosis Epidemiology in Iran and Diagnostic Techniques for Human, Livestock and Environment Samples. MEDICAL LABORATORY JOURNAL 2020. [DOI: 10.52547/mlj.14.6.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Na YS, Kim HL, Kim CM, Yun NR, Kim DM. Usefulness of Nested Polymerase Chain Reaction with Clinical Specimens for Diagnosis of Leptospirosis: a Case Series and a Review of Literature. J Korean Med Sci 2020; 35:e301. [PMID: 32924340 PMCID: PMC7490198 DOI: 10.3346/jkms.2020.35.e301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 06/26/2020] [Indexed: 12/03/2022] Open
Abstract
A culture of the Leptospira species and the microscopic agglutination test (MAT) are considered as the reference standard for the diagnosis of leptospirosis, but both tests are imperfect for early diagnosis. We describe 4 patients diagnosed with leptospirosis using nested polymerase chain reaction (N-PCR) that targeted the 16S rRNA gene and the passive hemagglutination assay (PHA). In our 4 cases, Leptospira DNA in the urine, plasma, or cerebrospinal fluid (CSF), was detected by N-PCR in the early phase of leptospirosis, except in the sample from the buffy coat. Especially, case 3 showed that N-PCR with the urine and CSF was positive 8 days after symptom onset, but not for the plasma or buffy coat. We report 4 cases of leptospirosis that were diagnosed by N-PCR that targeted the 16S rRNA gene with urine, plasma, or CSF, but not the buffy coat. Three were cured by doxycycline but the case 4 was fatal. Detection of Leptospira DNA by PCR from the urine and CSF, in addition to plasma, may be helpful to confirm the diagnosis.
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Affiliation(s)
- Yong Sub Na
- Department of Internal Medicine, Chosun University Hospital, Gwangju, Korea
| | - Hyun Lee Kim
- Department of Internal Medicine, Chosun University Hospital, Gwangju, Korea
| | - Choon Mee Kim
- Premedical Science, College of Medicine, Chosun University, Gwangju, Korea
| | - Na Ra Yun
- Department of Infectious Diseases, Chosun University Hospital, Gwangju, Korea
| | - Dong Min Kim
- Department of Infectious Diseases, Chosun University Hospital, Gwangju, Korea.
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Abstract
Abstract
Background
Leptospirosis, caused by pathogenic Leptospira spp., is a widespread zoonotic disease worldwide. Early diagnosis is required for proper patient management and reducing leptospirosis morbidity and mortality.
Objective
To summarize current literature regarding commonly used and new promising molecular approaches to Leptospira detection and diagnostic tests of human leptospirosis.
Method
The relevant articles in Leptospira and leptospirosis were retrieved from MEDLINE (PubMed) and Scopus.
Results
Several molecular techniques have been developed for diagnosis of human leptospirosis. Polymerase chain reaction-based techniques targeting on either lipL32 or 16S rRNA (rrs) gene are most commonly used to detect leptospiral DNA in various clinical specimens. Whole blood and urine are recommended specimens for suspected cases in the first (acute) and the second (immune) phases, respectively. Isothermal amplification with less expensive instrument is an alternative DNA detection technique that may be suitable for resource-limited laboratories.
Conclusion
Detection of leptospiral DNA in clinical specimens using molecular techniques enhances sensitivity for diagnosis of leptospirosis. The efficient and robust molecular detection especially in the early leptospiremic phase may prompt early and appropriate treatment leading to reduced morbidity and mortality of patients with leptospirosis.
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Affiliation(s)
- Teerasit Techawiwattanaboon
- Department of Microbiology, Faculty of Medicine , Chulalongkorn University , Bangkok 10330 , Thailand
- Chula Vaccine Research Center (Chula VRC), Center of Excellence in Vaccine Research and Development , Chulalongkorn University , Bangkok 10330 , Thailand
| | - Kanitha Patarakul
- Department of Microbiology, Faculty of Medicine , Chulalongkorn University , Bangkok 10330 , Thailand
- Chula Vaccine Research Center (Chula VRC), Center of Excellence in Vaccine Research and Development , Chulalongkorn University , Bangkok 10330 , Thailand
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Bertasio C, Papetti A, Scaltriti E, Tagliabue S, D’Incau M, Boniotti MB. Serological Survey and Molecular Typing Reveal New Leptospira Serogroup Pomona Strains among Pigs of Northern Italy. Pathogens 2020; 9:pathogens9050332. [PMID: 32365494 PMCID: PMC7281294 DOI: 10.3390/pathogens9050332] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 11/21/2022] Open
Abstract
Swine act as both maintenance and incidental hosts of pathogenic Leptospira spp. Here, a serological test was performed on 131,660 pig sera collected between 2002 and 2017 from 4715 farms in Northern Italy. A positivity rate of 13.05% was determined. Australis was the most frequently identified serogroup (77.29%), followed by Pomona (18.47%), Tarassovi (1.51%) and Icterohaemorrhagie (1.40%). Culture isolation and real-time Polymerase chain reaction (PCR) were carried out on 347 kidneys and 470 clinical samples, respectively. Overall, 133 strains were cultured successfully and 43 randomly chosen isolates were identified as serogroup Pomona. Multi-locus sequence typing (MLST) revealed that 41 isolates and 8 DNA extracted from biological samples belonged to sequence type 140. Using a multiple-locus, variable-number tandem repeat analysis, 43 samples produced identical profiles but, after 2014, three new Leptospira interrogans serogroup Pomona genotypes were observed. Interestingly, two isolates showed new MLST profiles and an unclassified identification by monoclonal antibodies. The 16S rRNA gene sequencing clustered them into L. kirschneri species and a core genome MLST analysis revealed an allelic identity of 96% compared with Mozdok strains. Genotyping allowed us to discriminate leptospires and to identify new emerging strains. The accurate identification of infective strains is required for formulating preventive methods and intervention strategies.
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Affiliation(s)
- Cristina Bertasio
- National Reference Centre for Animal Leptospirosis (NRCL), Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, via Bianchi 7/9, 25121 Brescia, Italy
- Correspondence: ; Tel.: +030-22-90-309
| | - Alice Papetti
- National Reference Centre for Animal Leptospirosis (NRCL), Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, via Bianchi 7/9, 25121 Brescia, Italy
| | - Erika Scaltriti
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, Strada dei Mercati 13/a, 43126 Parma, Italy
| | - Silvia Tagliabue
- National Reference Centre for Animal Leptospirosis (NRCL), Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, via Bianchi 7/9, 25121 Brescia, Italy
| | - Mario D’Incau
- National Reference Centre for Animal Leptospirosis (NRCL), Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, via Bianchi 7/9, 25121 Brescia, Italy
| | - Maria Beatrice Boniotti
- National Reference Centre for Animal Leptospirosis (NRCL), Istituto Zooprofilattico Sperimentale della Lombardia e dell’ Emilia Romagna “Bruno Ubertini”, via Bianchi 7/9, 25121 Brescia, Italy
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Epidemiological characterization of Leptospira spp. infection in working horses and in an occupationally exposed population in six Colombian police stations. ACTA ACUST UNITED AC 2019; 39:19-34. [PMID: 31529846 DOI: 10.7705/biomedica.v39i1.4475] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Indexed: 02/06/2023]
Abstract
Introduction: Police working horses are in close contact with their managers and the general population during recreational and patrol activities, which can favor the transmission of leptospirosis among the horses and the occupationally exposed personnel.
Objective. To characterize epidemiologically leptospirosis through serology, urine culture and PCR in working horses and in the occupationally exposed population in six police stations in Colombia.
Materials and methods. We tested 153 castrated male horses and 123 people in six police stations in the municipalities of Manizales, Pereira, Armenia, Ibagué, Tuluá, and Cali. Three structured formats were applied and blood samples were obtained from people and horses, which were processed with the Macroscopic Agglutination Test, (MAT) for 24 serogroups. Horses were subject to a clinical examination, and urine samples were obtained for urine culture and conventional PCR.
Results. The seroprevalence of human Leptospira spp. was 3.25% (n=4) while in horses it was 85% (n=130). Among the horses, serogroups Djasiman and Shermani were the most prevalent. The urine culture was positive in 64.7% (99/153) of the samples, whereas PCR analyzes were negative. A statistically significant association was found between the frequency of exiting the facilities (p=0.009) and the presence of wildlife (p=0.0051) with the infection by serogroup Shermani.
Conclusion. The epidemiological characteristics of leptospirosis in horses suggest an endemic presentation of the infection and its role as reservoirs of the bacteria; however, it is necessary to elucidate the pathogenesis of the disease with complementary studies.
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First Real-Time PCR in Morocco for Human Leptospirosis Using TaqMan Probes Targeting the LipL32 Gene. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2019. [DOI: 10.5812/archcid.67237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Li S, Liu Y, Chen X, Wang M, Hu W, Yan J. Visual and Rapid Detection of Leptospira interrogans Using Multiple Cross-Displacement Amplification Coupled with Nanoparticle-Based Lateral Flow Biosensor. Vector Borne Zoonotic Dis 2019; 19:604-612. [PMID: 30702382 DOI: 10.1089/vbz.2018.2395] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Leptospirosis is a worldwide zoonosis caused by spirochetes from the genus Leptospira. In the present study, a visual and rapid method for detecting Leptospira interrogans was developed based on multiple cross-displacement amplification (MCDA) and nanoparticle-based lateral flow biosensor (LFB). A set of 10 primers was specifically designed to recognize 10 regions of the lipL 41 gene of L. interrogans. The MCDA reaction was optimized at 64°C for only 40 min, and the amplification products were directly applied to the biosensor. The entire process, including DNA extraction (25 min), MCDA reaction (40 min), and result interpretation (∼2 min), could be completed within 70 min. Amplification products were detectable from as few as 10 genomic equivalents per reaction of pure L. interrogans DNA. No cross-reaction with nonpathogenic Leptospira or other bacteria was observed. The MCDA-LFB method established in the current report is suitable for the rapid screening of L. interrogans in clinical, animal, and environmental samples.
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Affiliation(s)
- Shijun Li
- 1Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, China
| | - Ying Liu
- 1Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, China
| | - Xu Chen
- 1Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, China
| | - Ming Wang
- 1Guizhou Provincial Centre for Disease Control and Prevention, Guiyang, China
| | - Weilin Hu
- 2Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jie Yan
- 2Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou, China
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Mohd Ali MR, Mohd Safee AW, Ismail NH, Abu Sapian R, Mat Hussin H, Ismail N, Yean Yean C. Development and validation of pan-Leptospira Taqman qPCR for the detection of Leptospira spp. in clinical specimens. Mol Cell Probes 2018. [PMID: 29524642 DOI: 10.1016/j.mcp.2018.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Early diagnosis of leptospirosis is important for ensuring better clinical management and achieving better outcomes. Currently, serological assays suffer from inconsistent performance and are less useful for early diagnosis of leptospirosis. As an alternative, qPCR is more sensitive, specific and able to detect the presence of leptospiral DNA during the acute phase of the infection. Meanwhile, most molecular assays do not detect the non-pathogenic group of Leptospira, even though these groups may also infect humans, although less frequently and less severely. METHODS A set of primers and probe targeting rrs genes of 22 Leptospira spp. were designed and evaluated on 31 Leptospira isolates, 41 other organisms and 65 clinical samples from suspected patients. RESULTS The developed assay was able to detect as low as 20 fg Leptospira DNA per reaction (equivalent to approximately 4 copies) and showed high specificity against the tested leptospiral strains. No cross amplification was observed with the other organisms. During the evaluation of the confirmed clinical specimens, the developed assay was able to correctly identify all positive samples (n = 10/10). One amplification was observed in a negative sample (n = 1/55). The sequencing of the PCR product of the discordant sample revealed that the sequences were similar to those of L. interrogans and L. kirschneri. CONCLUSION The findings suggest that the developed Taqman qPCR assay is sensitive, specific and has potential to be applied in a larger subsequent study.
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Affiliation(s)
- Mohammad Ridhuan Mohd Ali
- Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia; Secretariat National Institutes of Health (NIH), Ministry of Health Malaysia, c/o Institut Pengurusan Kesihatan, Jalan Rumah Sakit Bangsar, 59000 Kuala Lumpur, Malaysia
| | - Amira Wahida Mohd Safee
- Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Nor Hayati Ismail
- Kota Bharu Public Health Laboratory, Jalan Kuala Krai, 16010 Kota Bharu, Kelantan, Malaysia
| | - Roslinda Abu Sapian
- Secretariat National Institutes of Health (NIH), Ministry of Health Malaysia, c/o Institut Pengurusan Kesihatan, Jalan Rumah Sakit Bangsar, 59000 Kuala Lumpur, Malaysia
| | - Hani Mat Hussin
- Kota Bharu Public Health Laboratory, Jalan Kuala Krai, 16010 Kota Bharu, Kelantan, Malaysia
| | - Nabilah Ismail
- Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Chan Yean Yean
- Department of Medical Microbiology & Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia; Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.
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Woods K, Nic-Fhogartaigh C, Arnold C, Boutthasavong L, Phuklia W, Lim C, Chanthongthip A, Tulsiani SM, Craig SB, Burns MA, Weier SL, Davong V, Sihalath S, Limmathurotsakul D, Dance DAB, Shetty N, Zambon M, Newton PN, Dittrich S. A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos. Clin Microbiol Infect 2017; 24:1017.e1-1017.e7. [PMID: 29092789 PMCID: PMC6125144 DOI: 10.1016/j.cmi.2017.10.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/16/2017] [Accepted: 10/18/2017] [Indexed: 02/01/2023]
Abstract
OBJECTIVES To compare two molecular assays (rrs quantitative PCR (qPCR) versus a combined 16SrRNA and LipL32 qPCR) on different sample types for diagnosing leptospirosis in febrile patients presenting to Mahosot Hospital, Vientiane, Laos. METHODS Serum, buffy coat and urine samples were collected on admission, and follow-up serum ∼10 days later. Leptospira spp. culture and microscopic agglutination tests (MAT) were performed as reference standards. Bayesian latent class modelling was performed to estimate sensitivity and specificity of each diagnostic test. RESULTS In all, 787 patients were included in the analysis: 4/787 (0.5%) were Leptospira culture positive, 30/787 (3.8%) were MAT positive, 76/787 (9.7%) were rrs qPCR positive and 20/787 (2.5%) were 16SrRNA/LipL32 qPCR positive for pathogenic Leptospira spp. in at least one sample. Estimated sensitivity and specificity (with 95% CI) of 16SrRNA/LipL32 qPCR on serum (53.9% (33.3%-81.8%); 99.6% (99.2%-100%)), buffy coat (58.8% (34.4%-90.9%); 99.9% (99.6%-100%)) and urine samples (45.0% (27.0%-66.7%); 99.6% (99.3%-100%)) were comparable with those of rrs qPCR, except specificity of 16SrRNA/LipL32 qPCR on urine samples was significantly higher (99.6% (99.3%-100%) vs. 92.5% (92.3%-92.8%), p <0.001). Sensitivities of MAT (16% (95% CI 6.3%-29.4%)) and culture (25% (95% CI 13.3%-44.4%)) were low. Mean positive Cq values showed that buffy coat samples were more frequently inhibitory to qPCR than either serum or urine (p <0.001). CONCLUSIONS Serum and urine are better samples for qPCR than buffy coat, and 16SrRNA/LipL32 qPCR performs better than rrs qPCR on urine. Quantitative PCR on admission is a reliable rapid diagnostic tool, performing better than MAT or culture, with significant implications for clinical and epidemiological investigations of this global neglected disease.
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Affiliation(s)
- K Woods
- National Infection Service, Public Health England, London, UK; Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos.
| | - C Nic-Fhogartaigh
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Bart's Health Division of Infection, Pathology and Pharmacy Department, Royal London Hospital, London, UK
| | - C Arnold
- National Infection Service, Public Health England, London, UK
| | - L Boutthasavong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - W Phuklia
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - C Lim
- Mahidol-Oxford-Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - A Chanthongthip
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - S M Tulsiani
- Queensland Health Forensic and Scientific Service, WHO Collaborating Centre for Reference and Research on Leptospirosis, Brisbane, Qld, Australia
| | - S B Craig
- Queensland Health Forensic and Scientific Service, WHO Collaborating Centre for Reference and Research on Leptospirosis, Brisbane, Qld, Australia; University of the Sunshine Coast, Faculty of Science Health, Education and Engineering, Sippy Downs, Qld, Australia; Faculty of Health, Queensland University of Technology, Brisbane, Qld, Australia
| | - M-A Burns
- Queensland Health Forensic and Scientific Service, WHO Collaborating Centre for Reference and Research on Leptospirosis, Brisbane, Qld, Australia
| | - S L Weier
- Faculty of Health, Queensland University of Technology, Brisbane, Qld, Australia
| | - V Davong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - S Sihalath
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - D Limmathurotsakul
- Mahidol-Oxford-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, England, UK
| | - D A B Dance
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, England, UK; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - N Shetty
- National Infection Service, Public Health England, London, UK
| | - M Zambon
- National Infection Service, Public Health England, London, UK
| | - P N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, England, UK
| | - S Dittrich
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, England, UK; Foundation for Innovative New Diagnostics, Geneva, Switzerland
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Rapid, actionable diagnosis of urban epidemic leptospirosis using a pathogenic Leptospira lipL32-based real-time PCR assay. PLoS Negl Trop Dis 2017; 11:e0005940. [PMID: 28915243 PMCID: PMC5617227 DOI: 10.1371/journal.pntd.0005940] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/27/2017] [Accepted: 09/06/2017] [Indexed: 12/31/2022] Open
Abstract
Background With a conservatively estimated 1 million cases of leptospirosis worldwide and a 5–10% fatality rate, the rapid diagnosis of leptospirosis leading to effective clinical and public health decision making is of high importance, and yet remains a challenge. Methodology Based on parallel, population-based studies in two leptospirosis-endemic regions in Brazil, a real-time PCR assay which detects lipL32, a gene specifically present in pathogenic Leptospira, was assessed for the diagnostic effectiveness and accuracy. Patients identified by active hospital-based surveillance in Salvador and Curitiba during large urban leptospirosis epidemics were tested. Real-time PCR reactions were performed with DNA-extracted samples obtained from 127 confirmed and 23 unconfirmed cases suspected of leptospirosis, 122 patients with an acute febrile illness other than leptospirosis, and 60 healthy blood donors. Principal findings The PCR assay had a limit of detection of 280 Leptospira genomic equivalents/mL. Sensitivity for confirmed cases was 61% for whole blood and 29% for serum samples. Sensitivity was higher (86%) for samples collected within the first 6 days after onset of illness compared to those collected after 7 days (34%). The real-time PCR assay was able to detect leptospiral DNA in blood from 56% of serological non-confirmed cases. The overall specificity of the assay was 99%. Conclusions These findings indicate that real-time PCR may be a reliable tool for early diagnosis of leptospirosis, which is decisive for clinical management of severe and life-threatening cases and for public health decision making. In this study, we describe the performance testing and diagnostic accuracy assessment of a previously described real-time PCR assay aiming at the validation for early diagnosis of human leptospirosis. We found that diagnostic sensitivity was higher for EDTA whole blood samples (61%) than for serum samples (29%). We demonstrated that the molecular diagnosis was optimal when performed with EDTA whole samples collected within the first 6 days with symptoms, condition in which the sensitivity was 86%. The real-time PCR assay was able to detect leptospiral DNA in EDTA whole blood from 56% of serological non-confirmed cases for whom a convalescent sample was not available. The test overall specificity was 99%. Our findings demonstrate that real-time PCR is a reliable diagnostic tool suited for early diagnosis, and its results could support early medical interventions that could have a decisive impact on clinical outcome and thus decrease both the severity and fatality of cases.
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Dybing NA, Jacobson C, Irwin P, Algar D, Adams PJ. Leptospira Species in Feral Cats and Black Rats from Western Australia and Christmas Island. Vector Borne Zoonotic Dis 2017; 17:319-324. [DOI: 10.1089/vbz.2016.1992] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Narelle A. Dybing
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia
| | - Caroline Jacobson
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia
- Vector- and Water-Borne Pathogen Research Group, Murdoch University, Perth, Western Australia
| | - Peter Irwin
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia
- Vector- and Water-Borne Pathogen Research Group, Murdoch University, Perth, Western Australia
| | - David Algar
- Department of Parks and Wildlife, Wildlife Place, Woodvale, Western Australia
| | - Peter J. Adams
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia
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Application of a real time Polymerase Chain Reaction (PCR) assay for the early diagnosis of human leptospirosis in Sri Lanka. Biologicals 2016; 44:497-502. [DOI: 10.1016/j.biologicals.2016.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 09/06/2016] [Accepted: 09/09/2016] [Indexed: 11/22/2022] Open
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Chiani Y, Jacob P, Varni V, Landolt N, Schmeling MF, Pujato N, Caimi K, Vanasco B. Isolation and clinical sample typing of human leptospirosis cases in Argentina. INFECTION GENETICS AND EVOLUTION 2016; 37:245-51. [DOI: 10.1016/j.meegid.2015.11.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/26/2015] [Accepted: 11/29/2015] [Indexed: 11/29/2022]
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Tan CG, Dharmarajan G, Beasley J, Rhodes O, Moore G, Wu CC, Lin TL. Neglected leptospirosis in raccoons (Procyon lotor) in Indiana, USA. Vet Q 2014; 34:1-10. [DOI: 10.1080/01652176.2014.909960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Higino SSDS, Azevedo SSD. Leptospirose em pequenos ruminantes: situação epidemiológica atual no Brasil. ARQUIVOS DO INSTITUTO BIOLÓGICO 2014. [DOI: 10.1590/s1808-16572014000100017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A leptospirose em pequenos ruminantes é uma doença que pode causar perdas econômicas devido à ocorrência de abortamentos, natimortalidade e diminuição da produção de leite. A infecção pode se apresentar nas formas aguda, crônica e inaparente. Na forma aguda, pode ocorrer anorexia, depressão, dificuldade respiratória, febre, hemoglobinemia e hemoglobinúria. Na forma crônica, abortamentos e natimortalidade são comuns. Vários inquéritos sorológicos recentes conduzidos no Brasil apontaram frequências de soropositividade variando de 3,4 a 31,3% em caprinos, e de 0,7 a 34,6% em ovinos. Os sorovares reatores mais frequentes foram Autumnalis, Grippotyphosa, Hardjo, Icterohaemorrhagiae e Pyrogenes. O teste de soroaglutinação microscópica é o método mais empregado para o diagnóstico da infecção. O controle da leptospirose em pequenos ruminantes é baseado na identificação de fontes de infecção, controle de roedores, controle da aquisição de animais e imunização sistemática com vacinas inativadas que contenham sorovares de leptospiras regionais.
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Toyokawa T, Ohnishi M, Koizumi N. Diagnosis of acute leptospirosis. Expert Rev Anti Infect Ther 2014; 9:111-21. [DOI: 10.1586/eri.10.151] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Thongboonkerd V. Proteomics in leptospirosis research: towards molecular diagnostics and vaccine development. Expert Rev Mol Diagn 2014; 8:53-61. [DOI: 10.1586/14737159.8.1.53] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Rapid tests for diagnosis of leptospirosis: current tools and emerging technologies. Diagn Microbiol Infect Dis 2013; 78:1-8. [PMID: 24207075 DOI: 10.1016/j.diagmicrobio.2013.09.012] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/09/2013] [Accepted: 09/15/2013] [Indexed: 11/23/2022]
Abstract
Leptospirosis is an emerging zoonosis with a worldwide distribution but is more commonly found in impoverished populations in developing countries and tropical regions with frequent flooding. The rapid detection of leptospirosis is a critical step to effectively manage the disease and to control outbreaks in both human and animal populations. Therefore, there is a need for accurate and rapid diagnostic tests and appropriate surveillance and alert systems to identify outbreaks. This review describes current in-house methods and commercialized tests for the rapid diagnosis of acute leptospirosis. It focuses on diagnostic tests that can be performed with minimal training and limited equipment in less-developed and newly industrialized countries, particularly in resource-limited settings and with results in minutes to less than 4 hours. We also describe recent technological advances in the field of diagnostic tests that could allow for the development of innovative rapid tests in the near future.
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Schreier S, Doungchawee G, Chadsuthi S, Triampo D, Triampo W. Leptospirosis: current situation and trends of specific laboratory tests. Expert Rev Clin Immunol 2013; 9:263-80. [PMID: 23445200 DOI: 10.1586/eci.12.110] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Leptospirosis is re-emerging as a worldwide zoonosis and is caused by bacteria of the genus Leptospira. Human leptospirosis is associated with high temperature and humidity. Laboratory tests are indispensible for the early diagnosis and proper disease management. The demand for suitable leptospirosis point-of-care diagnostic tests grows with the awareness and number of incidences. Confirmation is achieved by the microscopic agglutination test, bacterial cultivation, PCR or histopathologic methods. However, high costs, poor standardization and/or elaborate sample preparation prevent routine use at the point of care. Cost-efficient, but insensitive serological methods dominate the diagnostic landscape and, likewise, urgently need improvement toward greater compliance with some of the point-of-care criteria. Combined application of antigen and antibody detection methods increases accuracy, but also new development or transfer of diagnostic technologies should be considered useful. Nano- and microparticle technology may play a key role in improving future antigen detection methods.
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Affiliation(s)
- Stefan Schreier
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
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Musso D, La Scola B. Laboratory diagnosis of leptospirosis: a challenge. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2013; 46:245-52. [PMID: 23639380 DOI: 10.1016/j.jmii.2013.03.001] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 02/01/2013] [Accepted: 03/07/2013] [Indexed: 11/30/2022]
Abstract
Leptospirosis is caused by pathogenic bacteria called leptospires that are transmitted directly or indirectly from animals to humans. It occurs worldwide but is most common in tropical and subtropical areas. It is a potentially serious but treatable disease. Its symptoms may mimic those of a number of other unrelated infections such as influenza, meningitis, hepatitis, dengue, or other viral hemorrhagic fevers. The spectrum of the disease is extremely wide, ranging from subclinical infection to a severe syndrome of multiorgan infection with high mortality. Laboratory diagnosis tests are not always available, especially in developing countries. Numerous tests have been developed, but availability of appropriate laboratory support is still a problem. Direct observation of leptospires by darkfield microscopy is unreliable and not recommended. Isolation of leptospires can take up to months and does not contribute to early diagnosis. Diagnosis is usually performed by serology; enzyme-linked immunosorbent assay and the microscopic agglutination tests are the laboratory methods generally used, rapid tests are also available. Limitation of serology is that antibodies are lacking at the acute phase of the disease. In recent years, several real-time polymerase chain reaction assays have been described. These can confirm the diagnosis in the early phase of the disease prior to antibody titers are at detectable levels, but molecular testing is not available in restricted resources areas.
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Affiliation(s)
- Didier Musso
- Laboratoire d'Analyses de Biologie Médicale, Institut Louis Malardé, Tahiti, French Polynesia.
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Picardeau M. Diagnosis and epidemiology of leptospirosis. Med Mal Infect 2013; 43:1-9. [DOI: 10.1016/j.medmal.2012.11.005] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 11/27/2012] [Indexed: 12/28/2022]
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Balassiano IT, Vital-Brazil JM, Pereira MM. Leptospirosis diagnosis by immunocapture polymerase chain reaction: a new tool for early diagnosis and epidemiologic surveillance. Diagn Microbiol Infect Dis 2012; 74:11-5. [PMID: 22770775 DOI: 10.1016/j.diagmicrobio.2012.05.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/23/2012] [Accepted: 05/31/2012] [Indexed: 12/22/2022]
Abstract
The aim of this study was to develop an immunocapture polymerase chain reaction (IC-PCR) protocol for leptospirosis. For the standardization of IC-PCR, polyclonal (AS) and monoclonal (MAb) antibodies against different serogroups and serovars of Leptospira were coupled to polystyrene plates. Human sera were artificially contaminated with leptospires and incubated on plates. The bacterial DNA was obtained and used in a multiplex PCR. Sensitivity was tested using sera contaminated with crescent concentrations of leptospires, while specificity was established using sera contaminated with different bacterial genera and sera obtained from patients positive for viral infections. IC-PCR using AS was able to recognize specific serogroups, although some cross-reactions have been observed. No cross-reactions were observed when MAbs were used; however, the sensitivity in this case was lower than that of IC-PCR using AS. IC-PCR proved to be specific to Leptospira and is a promising tool for early diagnosis of leptospirosis, providing additional information about the infecting serovar or serogroup.
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Affiliation(s)
- Ilana Teruszkin Balassiano
- Laboratório de Zoonoses Bacterianas, Centro de Referência Nacional para Leptospirose, WHO/PAHO Centro Colaborador para Leptospirose, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.
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Agampodi SB, Matthias MA, Moreno AC, Vinetz JM. Utility of quantitative polymerase chain reaction in leptospirosis diagnosis: association of level of leptospiremia and clinical manifestations in Sri Lanka. Clin Infect Dis 2012; 54:1249-55. [PMID: 22354922 DOI: 10.1093/cid/cis035] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Quantitative polymerase chain reaction (qPCR), despite cost and logistical challenges, has the potential to provide accurate and timely diagnosis for leptospirosis at the point-of-care in endemic areas. We studied optimal sample types for qPCR, timing of sampling, and clinical manifestations in relation to quantitative leptospiremia. METHODS A new qPCR assay using pathogenic Leptospira-specific 16S ribosomal RNA (rRNA) gene Taqman primers and an optimized temperature stepdown protocol was used to analyze patient blood samples. Serum was compared with whole blood as sample source. Quantitative leptospiremia was compared with clinical manifestations of leptospirosis and outcome. RESULTS The diagnostic sensitivity of qPCR of whole blood and serum was 18.4% (95% confidence interval [CI]: 9.97%-31.4%) and 51.0% (95% CI: 37.5%-64.4%) respectively. The qPCR on suspected cases confirmed infection in 58 of 381 cases (15.2%). Of these, 6 cases confirmed by nested polymerase chain reaction (PCR) and sequencing were serologically negative using a standard but not regionally optimized microscopic agglutination test panel. The bacterial load in serum/blood ranged from 10(2) to 10(6) Leptospira/mL. Median leptospiral load for uncomplicated, renal failure, myocarditis, and multi-organ failure patients were 8616, 11007, 36100, and 15882 Leptospira/mL respectively. The qPCR window of positivity ranged from day 2 to day 15; sensitivity of qPCR was not affected by the length of the interval between the onset of symptoms and sample collection (P = .328). CONCLUSIONS Quantitative PCR shows potential as a valid diagnostic test with a wider window of positivity than previously thought. Quantitative leptospiremia in serum/whole blood samples did not directly correlate with clinical manifestations of outcome in this patient population.
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Affiliation(s)
- Suneth B Agampodi
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093-0741, USA
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Comparison of real-time PCR assays for detection of pathogenic Leptospira spp. in blood and identification of variations in target sequences. J Clin Microbiol 2011; 49:2154-60. [PMID: 21471336 DOI: 10.1128/jcm.02452-10] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Leptospirosis is considered an underdiagnosed disease. Although several PCR-based methods are currently in use, there is little information on their comparability. In this study, four quantitative real-time PCR (qPCR) assays (SYBR green and TaqMan chemistries) targeting the secY, lfb1, and lipL32 genes were evaluated as diagnostic assays. In our hands, these assays can detect between 10(2) and 10(3) bacteria/ml of pure culture, whole-blood, plasma, and serum samples. In three independent experiments, we found a slightly higher sensitivity of the PCR assays in plasma than in whole blood and serum. We also evaluated the specificity of the PCR assays on reference Leptospira strains, including newly described Leptospira species, and clinical isolates. No amplification was detected for DNA obtained from saprophytic or intermediate Leptospira species. However, among the pathogens, we identified sequence polymorphisms in target genes that result in primer and probe mismatches and affect qPCR assay performance. In conclusion, most of these assays are sensitive and specific tools for routine diagnosis of leptospirosis. However, it is important to continually evaluate and, if necessary, modify the primers and/or probes used to ensure effective detection of the circulating Leptospira isolates.
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Sonthayanon P, Chierakul W, Wuthiekanun V, Thaipadungpanit J, Kalambaheti T, Boonsilp S, Amornchai P, Smythe LD, Limmathurotsakul D, Day NP, Peacock SJ. Accuracy of loop-mediated isothermal amplification for diagnosis of human leptospirosis in Thailand. Am J Trop Med Hyg 2011; 84:614-20. [PMID: 21460019 PMCID: PMC3062458 DOI: 10.4269/ajtmh.2011.10-0473] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 11/18/2010] [Indexed: 01/09/2023] Open
Abstract
There is a lack of diagnostic tests for leptospirosis in technology-restricted settings. We developed loop-mediated isothermal amplification (LAMP) specific for the 16S ribosomal RNA gene (rrs) of pathogenic and intermediate group Leptospira species. The lower limit of detection was 10 genomic equivalents/reaction, and analytical specificity was high; we observed positive reactions for pathogenic/intermediate groups and negative reactions for non-pathogenic Leptospira species and other bacterial species. We evaluated this assay in Thailand by using a case-control study of 133 patients with laboratory-proven leptospirosis and 133 patients with other febrile illnesses. Using admission blood, we found that the rrs LAMP showed positive results in 58 of 133 cases (diagnostic sensitivity = 43.6, 95% confidence interval [CI] = 35.0-52.5) and in 22 of 133 controls (diagnostic specificity = 83.5, 95% CI = 76.0-89.3). Sensitivity was high for 39 patients who were culture positive for Leptospira spp. (84.6, 95% CI = 69.5-94.1). The rrs LAMP can provide an admission diagnosis in approximately half of patients with leptospirosis, but its clinical utility is reduced by a lower specificity.
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Affiliation(s)
- Piengchan Sonthayanon
- Department of Clinical Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, 420/6 Rajvithi Road, Mahidol University, Bangkok, Thailand.
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Tulsiani SM, Craig SB, Graham GC, Cobbold RC, Dohnt MF, Burns MA, Leung LKP, Field HE, Smythe LD. High-resolution melt-curve analysis of random-amplified-polymorphic-DNA markers, for the characterisation of pathogenic Leptospira. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 104:151-61. [PMID: 20406582 DOI: 10.1179/136485910x12607012374037] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A new test for pathogenic Leptospira isolates, based on RAPD-PCR and high-resolution melt (HRM) analysis (which measures the melting temperature of amplicons in real time, using a fluorescent DNA-binding dye), has recently been developed. A characteristic profile of the amplicons can be used to define serovars or detect genotypes. Ten serovars, of leptospires from the species Leptospira interrogans (serovars Australis, Robinsoni, Hardjo, Pomona, Zanoni, Copenhageni and Szwajizak), L. borgpetersenii (serovar Arborea), L. kirschneri (serovar Cynopteri) and L. weilii (serovar Celledoni), were typed against 13 previously published RAPD primers, using a real-time cycler (the Corbett Life Science RotorGene 6000) and the optimised reagents from a commercial kit (Quantace SensiMix). RAPD-HRM at specific temperatures generated defining amplicon melt profiles for each of the tested serovars. These profiles were evaluated as difference-curve graphs generated using the RotorGene software package, with a cut-off of at least 8 'U' (plus or minus). The results demonstrated that RAPD-HRM can be used to measure serovar diversity and establish identity, with a high degree of stability. The characterisation of Leptospira serotypes using a DNA-based methodology is now possible. As an objective and relatively inexpensive and rapid method of serovar identification, at least for cultured isolates, RAPD-HRM assays show convincing potential.
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Affiliation(s)
- S M Tulsiani
- The University of Queensland, School of Veterinary Science, St Lucia, Queensland, Australia.
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Stoddard RA, Gee JE, Wilkins PP, McCaustland K, Hoffmaster AR. Detection of pathogenic Leptospira spp. through TaqMan polymerase chain reaction targeting the LipL32 gene. Diagn Microbiol Infect Dis 2009; 64:247-55. [PMID: 19395218 DOI: 10.1016/j.diagmicrobio.2009.03.014] [Citation(s) in RCA: 379] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 02/19/2009] [Accepted: 03/13/2009] [Indexed: 11/25/2022]
Abstract
Rapid diagnosis of leptospirosis, through culture and/or serology, can be difficult without proper expertise and is often delayed because of the length of time required to obtain results. In this study, we developed a real-time polymerase chain reaction (PCR) assay using a TaqMan probe targeting lipL32, which is present only in pathogenic Leptospira spp. Using Leptospira interrogans serovar Icterohaemorrhagiae DNA, the lower limit of detection was found to be 20 genomic equivalents/reaction with a 95% cutoff value. The assay detected pathogenic Leptospira strains, but not intermediately pathogenic or nonpathogenic strains. When testing the assay on spiked clinical specimens, whole blood and plasma were better specimens for detecting the same initial number of leptospires compared with serum from clotted and centrifuged blood. Leptospira spiked at the same concentration was better detected in centrifuged urine. This real-time PCR assay with high specificity and sensitivity may prove to be a rapid method for diagnosing acute leptospirosis.
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Affiliation(s)
- Robyn A Stoddard
- National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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A simple and rapid nested polymerase chain reaction–restriction fragment length polymorphism technique for differentiation of pathogenic and nonpathogenic Leptospira spp. Diagn Microbiol Infect Dis 2009; 63:251-6. [DOI: 10.1016/j.diagmicrobio.2008.10.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2008] [Revised: 10/27/2008] [Accepted: 10/30/2008] [Indexed: 11/19/2022]
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Lin X, Chen Y, Lu Y, Yan J, Yan J. Application of a loop-mediated isothermal amplification method for the detection of pathogenic Leptospira. Diagn Microbiol Infect Dis 2008; 63:237-42. [PMID: 19070450 DOI: 10.1016/j.diagmicrobio.2008.10.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 10/07/2008] [Accepted: 10/20/2008] [Indexed: 11/18/2022]
Abstract
Leptospirosis is an emerging infectious disease, which is considered to be the most widespread zoonotic disease in the world. There are more than 230 known serovars in the genus Leptospira. A loop-mediated isothermal amplification (LAMP) assay for the rapid detection of pathogenic Leptospira spp. was developed and evaluated through amplification of the lipL41 gene coding for the outer membrane protein LipL41. The LAMP assay did not rely on the isolation and culture of leptospires, and no cross-reactivity was observed with other bacterial species. A SYBR Green I-based LAMP assay was also carried out for the real-time detection of DNA amplification. The lower detection limit of the LAMP assay was approximately 100 copies, which was the same as the polymerase chain reaction (PCR) and real-time PCR assays. The accuracy of the LAMP reaction was confirmed by restriction endonuclease analysis of the amplified product. The LAMP assay is easy to perform and inexpensive, and so may be applied in the rapid and specific diagnosis of Leptospira.
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Affiliation(s)
- Xu'ai Lin
- Department of Medical Microbiology and Parasitology, Zhejiang University, Hangzhou, China
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Fearnley C, Wakeley P, Gallego-Beltran J, Dalley C, Williamson S, Gaudie C, Woodward M. The development of a real-time PCR to detect pathogenic Leptospira species in kidney tissue. Res Vet Sci 2008; 85:8-16. [DOI: 10.1016/j.rvsc.2007.09.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2007] [Revised: 08/20/2007] [Accepted: 09/04/2007] [Indexed: 11/30/2022]
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Victoria B, Ahmed A, Zuerner RL, Ahmed N, Bulach DM, Quinteiro J, Hartskeerl RA. Conservation of the S10-spc-alpha locus within otherwise highly plastic genomes provides phylogenetic insight into the genus Leptospira. PLoS One 2008; 3:e2752. [PMID: 18648538 PMCID: PMC2481283 DOI: 10.1371/journal.pone.0002752] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 06/24/2008] [Indexed: 11/21/2022] Open
Abstract
S10-spc-α is a 17.5 kb cluster of 32 genes encoding ribosomal proteins. This locus has an unusual composition and organization in Leptospira interrogans. We demonstrate the highly conserved nature of this region among diverse Leptospira and show its utility as a phylogenetically informative region. Comparative analyses were performed by PCR using primer sets covering the whole locus. Correctly sized fragments were obtained by PCR from all L. interrogans strains tested for each primer set indicating that this locus is well conserved in this species. Few differences were detected in amplification profiles between different pathogenic species, indicating that the S10-spc-α locus is conserved among pathogenic Leptospira. In contrast, PCR analysis of this locus using DNA from saprophytic Leptospira species and species with an intermediate pathogenic capacity generated varied results. Sequence alignment of the S10-spc-α locus from two pathogenic species, L. interrogans and L. borgpetersenii, with the corresponding locus from the saprophyte L. biflexa serovar Patoc showed that genetic organization of this locus is well conserved within Leptospira. Multilocus sequence typing (MLST) of four conserved regions resulted in the construction of well-defined phylogenetic trees that help resolve questions about the interrelationships of pathogenic Leptospira. Based on the results of secY sequence analysis, we found that reliable species identification of pathogenic Leptospira is possible by comparative analysis of a 245 bp region commonly used as a target for diagnostic PCR for leptospirosis. Comparative analysis of Leptospira strains revealed that strain H6 previously classified as L. inadai actually belongs to the pathogenic species L. interrogans and that L. meyeri strain ICF phylogenetically co-localized with the pathogenic clusters. These findings demonstrate that the S10-spc-α locus is highly conserved throughout the genus and may be more useful in comparing evolution of the genus than loci studied previously.
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Affiliation(s)
- Berta Victoria
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Santiago de Compostela, Galicia, Spain
| | - Ahmed Ahmed
- WHO/FAO/OIE and National Collaborating Centre for Reference and Research on Leptospirosis, Department of Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands
| | - Richard L. Zuerner
- Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, Iowa, United States of America
| | - Niyaz Ahmed
- Pathogen Evolution Laboratory, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Dieter M. Bulach
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Javier Quinteiro
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Santiago de Compostela, Galicia, Spain
| | - Rudy A. Hartskeerl
- WHO/FAO/OIE and National Collaborating Centre for Reference and Research on Leptospirosis, Department of Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands
- * E-mail:
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Abstract
PURPOSE OF REVIEW Leptospirosis is among the most important zoonotic diseases worldwide. Completion of the genomic sequences of leptospires has facilitated advances in diagnosis and prevention of the disease, and yielded insight into its pathogenesis. This article reviews this research, emphasizing recent progress. RECENT FINDINGS Leptospirosis is caused by a group of highly invasive spiral bacteria (spirochetes) that can infect both people and animals. Spirochetes can survive in the environment and host, and therefore outer membrane and secretory proteins that interact with the host are of considerable interest in leptospire research. The genetic approach to studying pathogenesis is hindered by fastidious growth of pathogenic leptospires. Integrated genomic and proteomic approaches, however, have yielded enhanced understanding of the pathogenesis of leptospirosis. Furthermore, studies of innate immune response to the organism have enhanced our understanding of host susceptibility and resistance to infection. In-silico analysis and high-throughput cloning and expression have had major impacts on efforts to develop vaccine candidates and diagnostic reagents. SUMMARY In the future, we must effectively utilize the wealth of genetic information to combat the disease. More studies into genetics, immune mechanisms that may be exploited to prevent leptospirosis, and pathogenesis of the disease are necessary.
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Affiliation(s)
- Raghavan U M Palaniappan
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
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Kositanont U, Chotinantakul K, Phulsuksombati D, Tribuddharat C. Assessment of Southern blot ribotyping for differentiation of Leptospira strains isolated from field rats. J Microbiol Methods 2007; 69:288-97. [PMID: 17346835 DOI: 10.1016/j.mimet.2007.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 01/08/2007] [Accepted: 01/24/2007] [Indexed: 11/22/2022]
Abstract
A Southern blot ribotyping based on EcoRV and HindIII digestion with two 16S and 23S rDNA probes for differentiating 27 Leptospira serovars was developed. The results between ribotyping and serotyping among 40 leptospiral strains isolated from field rats trapped in the northeastern region of Thailand during 1999-2000, were compared. A combination of Southern blot ribotyping, using EcoRV or HindIII digestion with both 16S and 23S rDNA as the probes, successfully typed 27 Leptospira serovars into 24 ribotypes with the discriminatory index (D) values of 0.99. The 16S- and 23S-EcoRV ribopatterns produced 17 and 9 profiles, respectively, with D values of 0.95 and 0.63, respectively. Ribopatterns of HindIII from both specific probes yielded 17 patterns. The D values of 16S- and 23S-HindIII ribopatterns were 0.94 and 0.93, respectively. With EcoRV digestion, the 16S rDNA probe was more discriminative than the 23S rDNA probe for differentiating Leptospira serovars. Moreover, the 16S-EcoRV (11 profiles), 16S-HindIII (11 profiles), and 23S-HindIII (10 profiles) ribopatterns produced higher numbers of distinct and unique profiles than the 23S-EcoRV (5 profiles). The results showed 100% concordance between ribotyping and serotyping, leading to all 40 isolates being successfully typed. The current study revealed that ribotyping as a quick and powerful tool for differentiating Leptospira serovars, has potential value in epidemiological studies.
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MESH Headings
- Animals
- Blotting, Southern/methods
- DNA Restriction Enzymes/chemistry
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- Leptospira/classification
- Leptospira/genetics
- Leptospira/isolation & purification
- Leptospirosis/diagnosis
- Leptospirosis/microbiology
- Polymerase Chain Reaction
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- Rats
- Ribotyping/methods
- Serotyping
- Thailand
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Affiliation(s)
- Uraiwan Kositanont
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
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