1
|
Parn S, Lewis G, Knight M. Inhibition of carbonic anhydrase using aspirin is a novel method to block schistosomiasis infection of the parasitic trematode, Schistosoma mansoni, in the intermediate snail host, Biomphalaria glabrata. Exp Parasitol 2023; 254:108618. [PMID: 37696327 DOI: 10.1016/j.exppara.2023.108618] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/18/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
Schistosomiasis is a major public health concern worldwide. Although praziquantel is currently available as the only treatment option for schistosomiasis, the absence of reliable diagnostic and prognostic tools highlights the need for the identification and characterization of new drug targets. Recently, we identified the B. glabrata homolog (accession number XP_013075832.1) of human CAXIV, showing 37% amino acid sequence identity, from a BLAST search in NCBI (National Center for Biotechnology Information). Carbonic Anhydrases (CAs) are metalloenzymes that catalyze the reversible hydration/dehydration of CO2/HCO3. These enzymes are associated with many physiological processes, and their role in tumorigenesis has been widely implicated. CAs create an acidic extracellular environment that facilitates the survival, metastasis, and growth of cancer cells. In this study, we investigated the role of CA inhibition in B. glabrata snails exposed to S. mansoni miracidia. We analyzed the expression of the B. glabrata CA encoding transcript in juvenile susceptible and resistant snails, with and without exposure to S. mansoni. Our results showed that the expression of the CA mRNA encoding transcript was upregulated during early and prolonged infection in susceptible snails (BBO2), but not in the resistant BS-90 stock. Notably, sodium salicylate, a form of aspirin, inhibited the expression of CA, post-exposure, to the parasite. Increasing research between parasites and cancer has shown that schistosomes and cancer cells share similarities in their capacity to proliferate, survive, and evade host immune mechanisms. Here, we show that this model system is a potential new avenue for understanding the role of CA in the metastasis and proliferation of cancer cells. Further studies are needed to explore the potential of CA as a biomarker for infection in other schistosomiasis-causing parasites, including S. japonicum and S. haematobium.
Collapse
Affiliation(s)
- Simone Parn
- Division of Science & Mathematics, University of the District of Columbia, 4200 Connecticut Ave, NW Washington, D.C., 20008, USA
| | - Gabriela Lewis
- Division of Science & Mathematics, University of the District of Columbia, 4200 Connecticut Ave, NW Washington, D.C., 20008, USA
| | - Matty Knight
- Division of Science & Mathematics, University of the District of Columbia, 4200 Connecticut Ave, NW Washington, D.C., 20008, USA; Department of Microbiology, Immunology & Tropical Medicine, Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University Ross Hall, 2300 I Street, NW Washington DC, 20037, USA.
| |
Collapse
|
2
|
Joof E, Sanneh B, Sambou SM, Wade CM. Species diversity and distribution of schistosome intermediate snail hosts in The Gambia. PLoS Negl Trop Dis 2021; 15:e0009823. [PMID: 34606509 PMCID: PMC8516291 DOI: 10.1371/journal.pntd.0009823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 10/14/2021] [Accepted: 09/20/2021] [Indexed: 11/18/2022] Open
Abstract
There is a need for recent information on intermediate snail hosts of schistosomes in The Gambia; the previous studies were conducted over three decades ago. This study assessed the incidence, species diversity, distribution and infection status of schistosome intermediate snail hosts in the country. Malacological surveys were conducted in all 5 regions of The Gambia: Central River Region (CRR), Upper River Region (URR), Western Region (WR), Lower River Region (LRR) and North Bank Region (NBR). Sampling of snails was undertaken at 114 sites that included permanent water bodies such as streams (bolongs), rice fields, irrigation canals and swamps; and temporal (seasonal) laterite pools. Ecological and physicochemical factors of sites were recorded. Snails were identified morphologically and screened for schistosome infections using molecular techniques. Freshwater snails were found at more than 50% (60/114) of sites sampled. While three species of Bulinus were collected, no Biomphalaria snails were found in any of the sites sampled. Of the total 2877 Bulinus snails collected, 75.9% were identified as Bulinus senegalensis, 20.9% as Bulinus forskalii and 3.2% as Bulinus truncatus. Seasonal pools produced the largest number of snails, and CRR was the region with the largest number of snails. Bulinus senegalensis was found more in seasonal pools as opposed to permanent sites, where B. forskalii and B. truncatus were observed to thrive. Bulinus snails were more common in seasonal sites where aquatic vegetation was present. In permanent sites, the abundance of snails increased with increase in water temperature and decrease in water pH. Bulinus senegalensis was found infected with both S. haematobium and S. bovis, while B. forskalii and B. truncatus had only S. bovis infection. While the human parasite S. haematobium was restricted to just four sites, the livestock parasite S. bovis had a much more widespread geographical distribution across both CRR and URR. This new information on the distribution of intermediate snail hosts of schistosomes in The Gambia will be vital for the national schistosomiasis control initiative. Several studies were conducted on intermediate snail hosts of schistosomes in The Gambia between the 1950s and 1980s, but there are few reports of similar studies in recent times. After The Gambia initiated its national control programme for schistosomiasis in 2014, the need arose for more and current information on schistosomiasis and the intermediate snail hosts involved indirectly in its transmission. We undertook a malacological survey of freshwater sites in all five regions (CRR, URR, WR, LRR and NBR) of The Gambia. While no Biomplalaria snails were found in any of the 114 sites sampled, three species of Bulinus snails were found. Of the total 2877 Bulinus snails collected, 75.9% were identified as Bulinus senegalensis, 20.9% as Bulinus forskalii and 3.2% as Bulinus truncatus. CRR had the highest number of snails amongst the regions and seasonal pools yielded the most snails amongst the habitat types sampled. Habitat type, water temperature and pH of sites were observed to have an influence on snail abundance. All three Bulinus snails were found infected with schistosome parasites. The human parasite (Schistosoma haematobium) had a much more restricted distribution as opposed to the livestock parasite (Schistosoma bovis) which had a wider geographical range. The study provides the first malacological report of intermediate snail hosts of schistosomes in The Gambia in over 3 decades and will be useful to the national schistosomiasis control programme.
Collapse
Affiliation(s)
- Ebrima Joof
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- National Public Health Laboratories, Ministry of Health and Social Welfare, Banjul, The Gambia
- * E-mail: (EJ); (CMW)
| | - Bakary Sanneh
- National Public Health Laboratories, Ministry of Health and Social Welfare, Banjul, The Gambia
| | - Sana M. Sambou
- Epidemiology and Disease Control Department, Ministry of Health and Social Welfare, Banjul, The Gambia
| | - Christopher M. Wade
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (EJ); (CMW)
| |
Collapse
|
3
|
Joof E, Andrus PS, Sowunmi K, Onyango VM, Wade CM. Comparing PCR techniques against conventional cercarial shedding methods for detecting Schistosoma mansoni infection in Biomphalaria snails. Acta Trop 2020; 212:105716. [PMID: 32966841 DOI: 10.1016/j.actatropica.2020.105716] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 10/23/2022]
Abstract
The detection of Schistosoma mansoni infection in both its intermediate (snail) and definitive (human) hosts is useful in providing information on the transmission of schistosomiasis. Three pairs of previously designed PCR primers (SM1-7, SMF/R & ND5) used for the detection of S. mansoni infection were tested. We assess the utility of each of these primer sets for detecting S. mansoni infection both in artificially exposed laboratory bred Biomphalaria glabrata, and field infected African Biomphalaria sudanica and Biomphalaria pfeifferi. Two of the three primer sets (SMF/R & ND5) detected S. mansoni infection in snails, but amplification of S. mansoni DNA with SM1-7 was unreliable. For the artificially exposed laboratory bred B. glabrata snails, SMF/R and ND5 both detected infection in more snails than the cercarial shedding method. Infection detection rates were 62.4% for ND5, 57.1% for SMF/R and 50.4% using traditional cercarial shedding methods. Both SMF/R and ND5 detected S. mansoni infection in 91% of snails observed shedding cercariae, increasing to 98.5% when low stringency PCR methods were used. When comparing each of the detection methods using a Bayesian latent class analysis model, ND5 had the highest detection sensitivity and negative predictive value (NPV), while SMF/R had the highest detection specificity and positive predictive value (PPV). In field collected Biomphalaria snails, ND5 detected S. mansoni infection in 21 of 24 snails categorised as shedding S. mansoni cercariae and 4 of 24 snails categorised as shedding non-S. mansoni cercariae, while SMF/R detected infection in 18 of 24 snails categorised as shedding S. mansoni cercariae and in 3 of 24 snails categorised as shedding non-S. mansoni cercariae. All SMF/R and ND5 PCR products were shown to be S. mansoni indicating that these field snails must have been infected with both S. mansoni and cercariae from other Schistosoma species. This indicates that the two primer sets are specific for S. mansoni and will not amplify non-S. mansoni species when used at their recommended annealing temperatures. Both the SMF/R and ND5 primers effectively detected S. mansoni infection in three Biomphalaria species and have improved detection sensitivity over cercarial shedding.
Collapse
|
4
|
Ajibola O, Gulumbe BH, Eze AA, Obishakin E. Tools for Detection of Schistosomiasis in Resource Limited Settings. Med Sci (Basel) 2018; 6:medsci6020039. [PMID: 29789498 PMCID: PMC6024580 DOI: 10.3390/medsci6020039] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/20/2022] Open
Abstract
Schistosomiasis is a debilitating disease affecting over 200 million people, with the highest burden of morbidity and mortality in African countries. Despite its huge impact on the health and socio-economic burden of the society, it remains a neglected tropical disease, with limited attention from governments and stakeholders in healthcare. One of the critical areas that is hugely under-developed is the development of accurate diagnostics for both intestinal and urogenital schistosomiasis. Diagnosis of schistosomiasis is important for the detection and treatment of disease in endemic and non-endemic settings. A conclusive detection method is also an indispensable part of treatment, both in the clinic and during mass drug administration (MDA), for the monitoring efficacy of treatment. Here, we review the available diagnostic methods and discuss the challenges encountered in diagnosis in resource limited settings. We also present the available diagnostics and cost implications for deployment in resource limited settings. Lastly, we emphasize the need for more funding directed towards the development of affordable diagnostic tools that is affordable for endemic countries as we work towards the elimination of the disease.
Collapse
Affiliation(s)
- Olumide Ajibola
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Bashar Haruna Gulumbe
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Anthonius Anayochukwu Eze
- Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu 400241, Enugu State, Nigeria.
| | - Emmanuel Obishakin
- Biotechnology Division, National Veterinary Research Institute, P.M.B. 001, Vom, Jos, 930281, Plateau State, Nigeria.
| |
Collapse
|
5
|
He P, Song LG, Xie H, Liang JY, Yuan DY, Wu ZD, Lv ZY. Nucleic acid detection in the diagnosis and prevention of schistosomiasis. Infect Dis Poverty 2016; 5:25. [PMID: 27025210 PMCID: PMC4812660 DOI: 10.1186/s40249-016-0116-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 03/14/2016] [Indexed: 11/25/2022] Open
Abstract
Schistosomiasis is an important zoonotic parasitic disease that causes serious harms to humans and animals. Surveillance and diagnosis play key roles in schistosomiasis control, however, current techniques for surveillance and diagnosis of the disease have limitations. As genome data for parasites are increasing, novel techniques for detection incorporating nucleotide sequences are receiving widespread attention. These sensitive, specific, and rapid detection methods are particularly important in the diagnosis of low-grade and early infections, and may prove to have clinical significance. This paper reviews the progress of nucleic acid detection in the diagnosis and prevention of schistosomiasis, including such aspects as the selection of target genes, and development and application of nucleic acid detection methods.
Collapse
Affiliation(s)
- Ping He
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.,Department of Pathogenic Biology, Medical School, Xizang Minzu University, Xianyang, 712082, China
| | - Lan-Gui Song
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Hui Xie
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Jin-Yi Liang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Dong-Ya Yuan
- Department of Pathogenic Biology, Medical School, Xizang Minzu University, Xianyang, 712082, China
| | - Zhong-Dao Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.
| | - Zhi-Yue Lv
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.
| |
Collapse
|
6
|
Kongklieng A, Kaewkong W, Intapan PM, Sanpool O, Janwan P, Thanchomnang T, Lulitanond V, Sri-Aroon P, Limpanont Y, Maleewong W. Molecular differentiation of Schistosoma japonicum and Schistosoma mekongi by real-time PCR with high resolution melting analysis. THE KOREAN JOURNAL OF PARASITOLOGY 2013; 51:651-6. [PMID: 24516269 PMCID: PMC3916453 DOI: 10.3347/kjp.2013.51.6.651] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/07/2013] [Accepted: 10/11/2013] [Indexed: 12/03/2022]
Abstract
Human schistosomiasis caused by Schistosoma japonicum and Schistosoma mekongi is a chronic and debilitating helminthic disease still prevalent in several countries of Asia. Due to morphological similarities of cercariae and eggs of these 2 species, microscopic differentiation is difficult. High resolution melting (HRM) real-time PCR is developed as an alternative tool for the detection and differentiation of these 2 species. A primer pair was designed for targeting the 18S ribosomal RNA gene to generate PCR products of 156 base pairs for both species. The melting points of S. japonicum and S. mekongi PCR products were 84.5±0.07℃ and 85.7±0.07℃, respectively. The method permits amplification from a single cercaria or an egg. The HRM real-time PCR is a rapid and simple tool for differentiation of S. japonicum and S. mekongi in the intermediate and final hosts.
Collapse
Affiliation(s)
- Amornmas Kongklieng
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Worasak Kaewkong
- Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Department of Biochemistry, Faculty of Medical Science, Naresuan University, Phitsanulok, 65000 Thailand
| | - Pewpan M Intapan
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Oranuch Sanpool
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Penchom Janwan
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Tongjit Thanchomnang
- Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Faculty of Medicine, Mahasarakham University, Mahasarakham 44000, Thailand
| | - Viraphong Lulitanond
- Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Pusadee Sri-Aroon
- Applied Malacology Center, Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Yanin Limpanont
- Applied Malacology Center, Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Wanchai Maleewong
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. ; Research and Diagnostic Center for Emerging Infectious Diseases, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| |
Collapse
|
7
|
Pyrosequencing for rapid molecular identification of Schistosoma japonicum and S. mekongi eggs and cercariae. Exp Parasitol 2013; 135:148-52. [PMID: 23831037 DOI: 10.1016/j.exppara.2013.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/17/2013] [Accepted: 06/24/2013] [Indexed: 11/21/2022]
Abstract
Schistosomiasis, which is caused by Schistosoma japonicum and S. mekongi, is a chronic and dangerous widespread disease affecting several countries in Asia. Differentiation between S. japonicum and S. mekongi eggs and/or cercariae via microscopic examination is difficult due to morphological similarities. It is important to identify these etiological agents isolated from animals and humans at the species or genotype level. In this study, a pyrosequencing assay designed to detect S. japonicum and S. mekongi DNA in fecal samples and infected snails was developed and evaluated as an alternative tool to diagnose schistosomiasis. New primers targeting the 18S ribosomal RNA gene were designated for specific amplification. S. japonicum and S. mekongi were identified using a 43-nucleotide pattern of the 18S ribosomal RNA gene and were differentiated using 7 nucleotides within this region. S. japonicum and S. mekongi-infected snails and fecal samples derived from infected mice and rats were differentially detected within a short period of time. The analytical sensitivity of the method enabled the identification of as little as a single cercaria artificially introduced into a pool of 10 non-infected snails and 2 eggs inoculated in 100mg of non-infected fecal sample. To evaluate the comparative efficacy of the assay, identical samples were also analyzed via microscopy and Sanger sequencing. The pyrosequencing technique was found to be superior to the microscopy method and more rapid than the Sanger sequencing method. These results suggest that the pyrosequencing assay is rapid, simple, sensitive and accurate in identifying S. japonicum and S. mekongi in intermediate hosts and fecal samples of the final host.
Collapse
|
8
|
Abstract
Since 1977, >2000 research papers described attempts to detect, identify and/or quantify parasites, or disease organisms carried by ecto-parasites, using DNA-based tests and 148 reviews of the topic were published. Despite this, only a few DNA-based tests for parasitic diseases are routinely available, and most of these are optional tests used occasionally in disease diagnosis. Malaria, trypanosomiasis, toxoplasmosis, leishmaniasis and cryptosporidiosis diagnosis may be assisted by DNA-based testing in some countries, but there are very few cases where the detection of veterinary parasites is assisted by DNA-based tests. The diagnoses of some bacterial (e.g. lyme disease) and viral diseases (e.g. tick borne encephalitis) which are transmitted by ecto-parasites more commonly use DNA-based tests, and research developing tests for these species makes up almost 20% of the literature. Other important uses of DNA-based tests are for epidemiological and risk assessment, quality control for food and water, forensic diagnosis and in parasite biology research. Some DNA-based tests for water-borne parasites, including Cryptosporidium and Giardia, are used in routine checks of water treatment, but forensic and food-testing applications have not been adopted in routine practice. Biological research, including epidemiological research, makes the widest use of DNA-based diagnostics, delivering enhanced understanding of parasites and guidelines for managing parasitic diseases. Despite the limited uptake of DNA-based tests to date, there is little doubt that they offer great potential to not only detect, identify and quantify parasites, but also to provide further information important for the implementation of parasite control strategies. For example, variant sequences within species of parasites and other organisms can be differentiated by tests in a manner similar to genetic testing in medicine or livestock breeding. If an association between DNA sequence and phenotype has been demonstrated, then qualities such as drug resistance, strain divergence, virulence, and origin of isolates could be inferred by DNA-based tests. No such tests are in clinical or commercial use in parasitology and few tests are available for other organisms. Why have DNA-based tests not had a bigger impact in veterinary and human medicine? To explore this question, technological, biological, economic and sociological factors must be considered. Additionally, a realistic expectation of research progress is needed. DNA-based tests could enhance parasite management in many ways, but patience, persistence and dedication will be needed to achieve this goal.
Collapse
|
9
|
Johnston DA, Dias Neto E, Simpson AJ, Rollinson D. Opening the can of worms: molecular analysis of schistosome populations. ACTA ACUST UNITED AC 2005; 9:286-91. [PMID: 15463780 DOI: 10.1016/0169-4758(93)90122-v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Schistosomatidae are dioecious digenean parasites of the blood vascular system of vertebrates. Of the 13 genera within the family, only Sehistosoma is associated with humans and, of the mammalian blood flukes, this genus has achieved the greatest geographical distribution and diversification in terms of recognized species and definitive hosts parasitized. In this review, Dave Johnston, Emmanuel Dias Neto, Andy Simpson and David Rollinson consider some recent molecular research that either sheds light on the micro-evolutionary changes occurring within schistosome populations or provides insights into broader, macro-evolutionary questions.
Collapse
Affiliation(s)
- D A Johnston
- Experimental Taxonomy Division, Department of Zoology, The Natural History Museum, Cromwell Road, London, UK SW7 5BD
| | | | | | | |
Collapse
|
10
|
Abbasi I, Hamburger J, Githure J, Ochola JJ, Agure R, Koech DK, Ramzy R, Gad A, Williams SA. Detection of Wuchereria bancrofti DNA in patients' sputum by the polymerase chain reaction. Trans R Soc Trop Med Hyg 1996; 90:531-2. [PMID: 8944264 DOI: 10.1016/s0035-9203(96)90308-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- I Abbasi
- Kuvin Centre for the Study of Infectious and Tropical Diseases, Hebrew University of Jerusalem, Israel
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Kaplan RM, Dame JB, Reddy GR, Courtney CH. A repetitive DNA probe for the sensitive detection of Fasciola hepatica infected snails. Int J Parasitol 1995; 25:601-10. [PMID: 7635638 DOI: 10.1016/0020-7519(94)00159-l] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Epizootiologic studies on F. hepatica frequently use microscopic techniques for the detection of infected snails, however, the poor efficiency, sensitivity, and specificity associated with these techniques limit their usefulness. A DNA-based test for the identification of snails infected with larval stages of F. hepatica would solve these problems and enable a level of detection accuracy previously unavailable. We have cloned and sequenced a 124 bp fragment of repetitive DNA from F. hepatica which hybridizes specifically with DNA of F. hepatica but not with DNA of its snail intermediate hosts Fossaria cubensis and Pseudosuccinea columella, or with DNA of Fascioloides magna and Paramphistomum liorchis, ruminant trematodes which share the same intermediate host and same enzootic range as F. hepatica. Using this 124 bp fragment as a probe, infection in snails was detected immediately following miracidial penetration, thus a sensitivity equivalent to the minimum biologic unit of the parasite was achieved. This 124 bp repeated sequence belongs to a large family of 124 bp repeats that share a high level of sequence identity and constitute approximately 15% of the F. hepatica genome. We also report here the development of a quick and inexpensive DNA extraction protocol for use in field-collected snails. Thus, we have developed both a highly sensitive and specific DNA probe and a means to use the probe in a large epizootiologic study of F. hepatica where thousands of field-collected snails need to be assayed for infection.
Collapse
Affiliation(s)
- R M Kaplan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Florida, Gainesville 32611-0880, USA
| | | | | | | |
Collapse
|
12
|
Rollinson D, Walker TK, Knowles RJ, Simpson AJG. Identification of schistosome hybrids and larval parasites using rRNA probes. Syst Parasitol 1990. [DOI: 10.1007/bf00009918] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|