1
|
A Fluorescence in Situ Hybridization (FISH) Test for Diagnosing Babesiosis. Diagnostics (Basel) 2020; 10:diagnostics10060377. [PMID: 32517217 PMCID: PMC7344499 DOI: 10.3390/diagnostics10060377] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/23/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022] Open
Abstract
Apicomplexan parasites of the genus Babesia cause babesiosis in humans and animals. The microscopic examination of stained blood smears, detection of serum antibodies by immunoassays, and PCR-based identification of parasite nucleic acid in blood are common laboratory methods for diagnosing babesiosis. The present study evaluated a commercially available Babesia genus-specific fluorescence in situ hybridization (FISH) test for detecting Babesia parasites in blood smears. The FISH test detected Babesia duncani and Babesia microti, two common species that cause human infections in the USA, and other Babesia species of human and veterinary importance in less than two hours. The Babesia genus-specific FISH test supplements other existing laboratory methods for diagnosing babesiosis and may be particularly useful in resource-limited laboratories.
Collapse
|
2
|
Suss PH, Ribeiro VST, Cieslinski J, Kraft L, Tuon FF. Experimental procedures for decontamination and microbiological testing in cardiovascular tissue banks. Exp Biol Med (Maywood) 2019; 243:1286-1301. [PMID: 30614255 DOI: 10.1177/1535370218820515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
IMPACT STATEMENT Sterility testing is a critical issue in the recovery, processing, and release of tissue allografts. Contaminated allografts are often discarded, increasing costs, and reducing tissue stocks. Given these concerns, it is important to determine the most effective methodology for sterility testing. This work provides an overview of microbiological methods for sampling and culturing donor grafts for cardiovascular tissue banking.
Collapse
Affiliation(s)
- Paula Hansen Suss
- 1 Laboratory of Emerging Infectious Diseases, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil
| | - Victoria Stadler Tasca Ribeiro
- 1 Laboratory of Emerging Infectious Diseases, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil
| | - Juliette Cieslinski
- 1 Laboratory of Emerging Infectious Diseases, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil
| | - Letícia Kraft
- 1 Laboratory of Emerging Infectious Diseases, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil
| | - Felipe Francisco Tuon
- 1 Laboratory of Emerging Infectious Diseases, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil.,2 Human Tissue Bank, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901, Brazil
| |
Collapse
|
3
|
Vande Burgt NH, Auer A, Zintl A. Comparison of in vitro viability methods for Cryptosporidium oocysts. Exp Parasitol 2018. [DOI: 10.1016/j.exppara.2018.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
Rousseau A, La Carbona S, Dumètre A, Robertson LJ, Gargala G, Escotte-Binet S, Favennec L, Villena I, Gérard C, Aubert D. Assessing viability and infectivity of foodborne and waterborne stages (cysts/oocysts) of Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii: a review of methods. ACTA ACUST UNITED AC 2018; 25:14. [PMID: 29553366 PMCID: PMC5858526 DOI: 10.1051/parasite/2018009] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 02/09/2018] [Indexed: 11/14/2022]
Abstract
Giardia duodenalis, Cryptosporidium spp. and Toxoplasma gondii are protozoan parasites that have been highlighted as emerging foodborne pathogens by the Food and Agriculture Organization of the United Nations and the World Health Organization. According to the European Food Safety Authority, 4786 foodborne and waterborne outbreaks were reported in Europe in 2016, of which 0.4% were attributed to parasites including Cryptosporidium, Giardia and Trichinella. Until 2016, no standardized methods were available to detect Giardia, Cryptosporidium and Toxoplasma (oo)cysts in food. Therefore, no regulation exists regarding these biohazards. Nevertheless, considering their low infective dose, ingestion of foodstuffs contaminated by low quantities of these three parasites can lead to human infection. To evaluate the risk of protozoan parasites in food, efforts must be made towards exposure assessment to estimate the contamination along the food chain, from raw products to consumers. This requires determining: (i) the occurrence of infective protozoan (oo)cysts in foods, and (ii) the efficacy of control measures to eliminate this contamination. In order to conduct such assessments, methods for identification of viable (i.e. live) and infective parasites are required. This review describes the methods currently available to evaluate infectivity and viability of G. duodenalis cysts, Cryptosporidium spp. and T. gondii oocysts, and their potential for application in exposure assessment to determine the presence of the infective protozoa and/or to characterize the efficacy of control measures. Advantages and limits of each method are highlighted and an analytical strategy is proposed to assess exposure to these protozoa.
Collapse
Affiliation(s)
- Angélique Rousseau
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France - ACTALIA Food Safety Department, 310 Rue Popielujko, 50000 Saint-Lô, France - EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | | | - Aurélien Dumètre
- Aix Marseille Univ, IRD (Dakar, Marseille, Papeete), AP-HM, IHU-Méditerranée Infection, UMR Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Lucy J Robertson
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, PO Box 8146 Dep., 0033, Oslo, Norway
| | - Gilles Gargala
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | - Sandie Escotte-Binet
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
| | - Loïc Favennec
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | - Isabelle Villena
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
| | - Cédric Gérard
- Food Safety Microbiology, Nestlé Research Center, PO Box 44, CH-1000 Lausanne 26, Switzerland
| | - Dominique Aubert
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
| |
Collapse
|
5
|
Deshmukh RA, Joshi K, Bhand S, Roy U. Recent developments in detection and enumeration of waterborne bacteria: a retrospective minireview. Microbiologyopen 2016; 5:901-922. [PMID: 27397728 PMCID: PMC5221461 DOI: 10.1002/mbo3.383] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/20/2016] [Accepted: 05/02/2016] [Indexed: 12/17/2022] Open
Abstract
Waterborne diseases have emerged as global health problems and their rapid and sensitive detection in environmental water samples is of great importance. Bacterial identification and enumeration in water samples is significant as it helps to maintain safe drinking water for public consumption. Culture‐based methods are laborious, time‐consuming, and yield false‐positive results, whereas viable but nonculturable (VBNCs) microorganisms cannot be recovered. Hence, numerous methods have been developed for rapid detection and quantification of waterborne pathogenic bacteria in water. These rapid methods can be classified into nucleic acid‐based, immunology‐based, and biosensor‐based detection methods. This review summarizes the principle and current state of rapid methods for the monitoring and detection of waterborne bacterial pathogens. Rapid methods outlined are polymerase chain reaction (PCR), digital droplet PCR, real‐time PCR, multiplex PCR, DNA microarray, Next‐generation sequencing (pyrosequencing, Illumina technology and genomics), and fluorescence in situ hybridization that are categorized as nucleic acid‐based methods. Enzyme‐linked immunosorbent assay (ELISA) and immunofluorescence are classified into immunology‐based methods. Optical, electrochemical, and mass‐based biosensors are grouped into biosensor‐based methods. Overall, these methods are sensitive, specific, time‐effective, and important in prevention and diagnosis of waterborne bacterial diseases.
Collapse
Affiliation(s)
- Rehan A Deshmukh
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Kopal Joshi
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Sunil Bhand
- Biosensor Lab, Department of Chemistry, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| | - Utpal Roy
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani-K.K. Birla Goa Campus, NH17B Bypass, Zuarinagar, Goa, 403726, India
| |
Collapse
|
6
|
Destura RV, Cena RB, Galarion MJH, Pangilinan CM, Arevalo GM, Alba ROC, Petronio JAG, Salem GM, Schwem B, Sevilleja JEAD. Advancing Cryptosporidium Diagnostics from Bench to Bedside. CURRENT TROPICAL MEDICINE REPORTS 2015. [DOI: 10.1007/s40475-015-0055-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
7
|
Real-time PCR methodology for selective detection of viable Escherichia coli O157:H7 cells by targeting Z3276 as a genetic marker. Appl Environ Microbiol 2012; 78:5297-304. [PMID: 22635992 DOI: 10.1128/aem.00794-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The goal of this study was to develop a sensitive, specific, and accurate method for the selective detection of viable Escherichia coli O157:H7 cells in foods. A unique open reading frame (ORF), Z3276, was identified as a specific genetic marker for the detection of E. coli O157:H7. We developed a real-time PCR assay with primers and probe targeting ORF Z3276 and confirmed that this assay was sensitive and specific for E. coli O157:H7 strains (n = 298). Using this assay, we can detect amounts of genomic DNA of E. coli O157:H7 as low as a few CFU equivalents. Moreover, we have developed a new propidium monoazide (PMA)-real-time PCR protocol that allows for the clear differentiation of viable from dead cells. In addition, the protocol was adapted to a 96-well plate format for easy and consistent handling of a large number of samples. Amplification of DNA from PMA-treated dead cells was almost completely inhibited, in contrast to the virtually unaffected amplification of DNA from PMA-treated viable cells. With beef spiked simultaneously with 8 × 10(7) dead cells/g and 80 CFU viable cells/g, we were able to selectively detect viable E. coli O157:H7 cells with an 8-h enrichment. In conclusion, this PMA-real-time PCR assay offers a sensitive and specific means to selectively detect viable E. coli O157:H7 cells in spiked beef. It also has the potential for high-throughput selective detection of viable E. coli O157:H7 cells in other food matrices and, thus, will have an impact on the accurate microbiological and epidemiological monitoring of food safety and environmental sources.
Collapse
|
8
|
An advanced dual labeled gold nanoparticles probe to detect Cryptosporidium parvum using rapid immuno-dot blot assay. Biosens Bioelectron 2011; 26:4624-7. [DOI: 10.1016/j.bios.2011.05.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 04/22/2011] [Accepted: 05/04/2011] [Indexed: 11/20/2022]
|
9
|
Hijjawi N, Estcourt A, Yang R, Monis P, Ryan U. Complete development and multiplication of Cryptosporidium hominis in cell-free culture. Vet Parasitol 2010; 169:29-36. [DOI: 10.1016/j.vetpar.2009.12.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 12/02/2009] [Accepted: 12/14/2009] [Indexed: 11/17/2022]
|
10
|
Zintl A, Keogh B, Ezzaty-Mirhashemi M, De Waal T, Scholz D, Mulcahy G. Survival of Cryptosporidium parvum
oocysts in the presence of hydrated lime. Vet Rec 2010; 166:297-300. [DOI: 10.1136/vr.c1157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- A. Zintl
- School of Agriculture, Food Science and Veterinary Medicine
| | - B. Keogh
- Clogrennane Lime; Clogrennane County Carlow Ireland
| | | | - T. De Waal
- School of Agriculture, Food Science and Veterinary Medicine
| | - D. Scholz
- Conway Institute; University College Dublin, Belfield; Dublin 4 Ireland
| | - G. Mulcahy
- School of Agriculture, Food Science and Veterinary Medicine
| |
Collapse
|
11
|
Adav SS, Lin JCT, Yang Z, Whiteley CG, Lee DJ, Peng XF, Zhang ZP. Stereological assessment of extracellular polymeric substances, exo-enzymes, and specific bacterial strains in bioaggregates using fluorescence experiments. Biotechnol Adv 2010; 28:255-80. [DOI: 10.1016/j.biotechadv.2009.08.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 08/07/2009] [Accepted: 08/08/2009] [Indexed: 10/20/2022]
|
12
|
Brescia CC, Griffin SM, Ware MW, Varughese EA, Egorov AI, Villegas EN. Cryptosporidium propidium monoazide-PCR, a molecular biology-based technique for genotyping of viable Cryptosporidium oocysts. Appl Environ Microbiol 2009; 75:6856-63. [PMID: 19749067 PMCID: PMC2772443 DOI: 10.1128/aem.00540-09] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 08/28/2009] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidium is an important waterborne protozoan parasite that can cause severe diarrhea and death in the immunocompromised. The current methods used to monitor for Cryptosporidium oocysts in water are the microscopy-based USEPA methods 1622 and 1623. These methods assess total levels of oocysts in source waters, but do not determine oocyst viability or genotype. Recently, propidium monoazide (PMA) has been used in conjunction with molecular diagnostic tools to identify species and assess the viability of bacteria. The goal of this study was the development of a Cryptosporidium PMA-PCR (CryptoPMA-PCR) assay that includes PMA treatment prior to PCR analysis in order to prevent the amplification of DNA from dead oocysts. The results demonstrated that PMA penetrates only dead oocysts and blocks amplification of their DNA. The CryptoPMA-PCR assay can also specifically detect live oocysts within a mixed population of live and dead oocysts. More importantly, live oocysts, not dead oocysts, were detected in raw waste or surface water samples spiked with Cryptosporidium oocysts. This proof-of-concept study is the first to demonstrate the use of PMA for pre-PCR treatment of Cryptosporidium oocysts. The CryptoPMA-PCR assay is an attractive approach to specifically detect and genotype viable Cryptosporidium oocysts in the water, which is critical for human health risk assessment.
Collapse
Affiliation(s)
- Cristin C. Brescia
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| | - Shannon M. Griffin
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| | - Michael W. Ware
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| | - Eunice A. Varughese
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| | - Andrey I. Egorov
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| | - Eric N. Villegas
- National Exposure Research Laboratory, National Center for Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268
| |
Collapse
|
13
|
Singh J, Behal A, Singla N, Joshi A, Birbian N, Singh S, Bali V, Batra N. Metagenomics: Concept, methodology, ecological inference and recent advances. Biotechnol J 2009; 4:480-94. [PMID: 19288513 DOI: 10.1002/biot.200800201] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Microorganisms constitute two third of the Earth's biological diversity. As many as 99% of the microorganisms present in certain environments cannot be cultured by standard techniques. Culture-independent methods are required to understand the genetic diversity, population structure and ecological roles of the majority of organisms. Metagenomics is the genomic analysis of microorganisms by direct extraction and cloning of DNA from their natural environment. Protocols have been developed to capture unexplored microbial diversity to overcome the existing barriers in estimation of diversity. New screening methods have been designed to select specific functional genes within metagenomic libraries to detect novel biocatalysts as well as bioactive molecules applicable to mankind. To study the complete gene or operon clusters, various vectors including cosmid, fosmid or bacterial artificial chromosomes are being developed. Bioinformatics tools and databases have added much to the study of microbial diversity. This review describes the various methodologies and tools developed to understand the biology of uncultured microbes including bacteria, archaea and viruses through metagenomic analysis.
Collapse
Affiliation(s)
- Jagtar Singh
- Department of Biotechnology, Panjab University, Chandigarh, India
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Garcés-Sanchez G, Wilderer PA, Munch JC, Horn H, Lebuhn M. Evaluation of two methods for quantification of hsp70 mRNA from the waterborne pathogen Cryptosporidium parvum by reverse transcription real-time PCR in environmental samples. WATER RESEARCH 2009; 43:2669-2678. [PMID: 19401258 DOI: 10.1016/j.watres.2009.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 03/09/2009] [Accepted: 03/16/2009] [Indexed: 05/27/2023]
Abstract
We optimized and evaluated two mRNA extraction methods to quantify induced hsp70 mRNA from viable and injured Cryptosporidium parvum oocysts by reverse transcription quantitative real-time PCR (RT-qPCR) in raw and treated manure. Methods based on guanidinium isothiocyanate/phenol/chloroform (GITC-PC) purification and direct mRNA extraction with magnetic oligo(dT)25-coated beads were evaluated for applicability and sensitivity. Both methods proved to be suitable for processing manure samples. With washed manure samples and oocyst disruption by bead beating for 165 s in time intervals with cumulative pooling of the lysate fractions, optimum RT-qPCR results were achieved. On average, 2.6 times more hsp70 mRNA was detected with the oligo(dT)25 method in comparison to the GITC-PC based method using fresh oocysts, whereas less mRNA was detected in aged oocysts. For fresh oocysts, analytical and method detection limits for the oligo(dT)25 based method were 1.7 cDNA copies/qPCR reaction and 5150 oocysts/mL manure, and for the GITC-PC based method 17 cDNA copies/qPCR reaction and 4950 oocysts/mL, respectively. In 12 months old oocysts with reduced viability, mRNA was occasionally detected only by the GITC-PC based method. Failure of or reduced detection with the oligo(dT)25 based method was apparently a result of weakened oocyst walls leading to quicker release of mRNA and therefore mRNA shredding by bead beating in the relatively long stretch between the capture sequence and the RT-qPCR target sites.
Collapse
Affiliation(s)
- Gabriela Garcés-Sanchez
- Institute of Water Quality Control, Technische Universität München, Am Coulombwall, 85748 Garching, Germany.
| | | | | | | | | |
Collapse
|
15
|
Propagation of human enteropathogens in constructed horizontal wetlands used for tertiary wastewater treatment. Appl Environ Microbiol 2009; 75:4531-8. [PMID: 19411413 DOI: 10.1128/aem.02873-08] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Constructed subsurface flow (SSF) and free-surface flow (FSF) wetlands are being increasingly implemented worldwide into wastewater treatments in response to the growing need for microbiologically safe reclaimed waters, which is driven by an exponential increase in the human population and limited water resources. Wastewater samples from four SSF and FSF wetlands in northwestern Ireland were tested qualitatively and quantitatively for Cryptosporidium spp., Giardia duodenalis, and human-pathogenic microsporidia, with assessment of their viability. Overall, seven species of human enteropathogens were detected in wetland influents, vegetated areas, and effluents: Cryptosporidium parvum, C. hominis, C. meleagridis, C. muris, G. duodenalis, Encephalitozoon hellem, and Enterocytozoon bieneusi. SSF wetland had the highest pathogen removal rate (i.e., Cryptosporidium, 97.4%; G. duodenalis, 95.4%); however, most of these values for FSF were in the negative area (mean, -84.0%), meaning that more pathogens were discharged by FSF wetlands than were delivered to wetlands with incoming wastewater. We demonstrate here that (i) the composition of human enteropathogens in wastewater entering and leaving SSF and FSF wetlands is highly complex and dynamic, (ii) the removal and inactivation of human-pathogenic microorganisms were significantly higher at the SSF wetland, (iii) FSF wetlands may not always provide sufficient remediation for human enteropathogens, (iv) wildlife can contribute a substantial load of human zoonotic pathogens to wetlands, (v) most of the pathogens discharged by wetlands were viable, (vi) large volumes of wetland effluents can contribute to contamination of surface waters used for recreation and drinking water abstraction and therefore represent a serious public health threat, and (vii) even with the best pathogen removal rates achieved by SSF wetland, the reduction of pathogens was not enough for a safety reuse of the reclaimed water. To our knowledge, this is the first report of C. meleagridis from Ireland.
Collapse
|
16
|
Graczyk TK, Lucy FE, Mashinsky Y, Andrew Thompson RC, Koru O, Dasilva AJ. Human zoonotic enteropathogens in a constructed free-surface flow wetland. Parasitol Res 2009; 105:423-8. [PMID: 19343366 DOI: 10.1007/s00436-009-1400-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 03/08/2009] [Indexed: 10/21/2022]
Abstract
Effluents from a small-scale free-surface flow constructed wetland, used for polishing of secondary treated wastewater, contained significantly higher concentrations of potentially viable Giardia duodenalis cysts and Enterocytozoon bieneusi spores than did wetland influents consisting of secondary treated wastewater. Zoonotic Assemblage A of G. duodenalis cysts was identified in wetland inflows, while Assemblage A and two nonhuman infective Assemblages (i.e., C, and E) were present in wetland effluents. E. bieneusi spores represented genotype K based on DNA sequencing analysis of internal transcribed spacer. The study demonstrated that: (1) free-surface flow small-scale constructed wetlands may not provide sufficient remediation for human zoonotic protozoa and fungi present in secondary treated wastewater; (2) dogs and livestock can substantially contribute human-pathogenic protozoan and fungal microorganisms to engineered vegetated wetland systems; and (3) large volumes of wetland effluents can contribute to contamination of surface waters used for recreation and drinking water abstraction and therefore represent a serious public health threat.
Collapse
Affiliation(s)
- Thaddeus K Graczyk
- Department of Environmental Health Sciences, Division of Environmental Health Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA.
| | | | | | | | | | | |
Collapse
|
17
|
Xiao L. Overview of Cryptosporidium presentations at the 10th International Workshops on Opportunistic Protists. EUKARYOTIC CELL 2009; 8:429-36. [PMID: 19168753 PMCID: PMC2669211 DOI: 10.1128/ec.00295-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Lihua Xiao
- Division of Parasitic Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
| |
Collapse
|
18
|
Ueno R. Visualization of sporopollenin-containing pathogenic green micro-alga Prototheca wickerhamii by fluorescent in situ hybridization (FISH). Can J Microbiol 2009; 55:465-72. [DOI: 10.1139/w08-155] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fluorescent in situ hybridization (FISH) using taxon-specific, rRNA-targeted oligonucleotide probes is one of the most powerful tools for the rapid identification of harmful microorganisms. However, eukaryotic algal cells do not always allow FISH probes to permeate over their cell walls. Members of the pathogenic micro-algal genus Prototheca are characterized by their distinctive cell-wall component, sporopollenin, an extremely tough biopolymer that resists acid and alkaline hydrolysis, enzyme attack, and acetolysis. To our knowledge, there has been no report of the successful permeation by the oligonucleotide probes over the cell walls of unicellular green micro-algae, which contain sporopollenin. The DNA probes passed through the cell wall of Prototheca wickerhamii after treating the algal cells with cetyltrimethylammonium bromide (CTAB). Most cells in the middle logarithmic growth phase culture fluoresced when hybridized with the rRNA-targeted universal probe for eukaryotes, though individual cells included in this culture differed in the level of cell-wall vulnerability to attack by the polysaccharide-degrading enzyme, thus reflecting the different stages of the life cycle. This is the first report regarding the visualization of sporopollenin-containing, green micro-algal cells by FISH.
Collapse
Affiliation(s)
- Ryohei Ueno
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, 108-8477, Japan. (e-mail: )
| |
Collapse
|
19
|
Ormeci B, Linden KG. Development of a fluorescence in situ hybridization protocol for the identification of micro-organisms associated with wastewater particles and flocs. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2008; 43:1484-1488. [PMID: 18821232 DOI: 10.1080/10934520802293586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Fluorescence in situ hybridization (FISH) provides a unique tool to study micro-organisms associated with particles and flocs. FISH enables visual examination of micro-organisms while they are structurally intact and associated with particles. However, application of FISH to wastewater and sludge samples presents a specific set of problems. Wastewater samples generate high background fluorescence due to their organic and inorganic content making it difficult to differentiate a probe-conferred signal from naturally fluorescing particles with reasonable certainty. Furthermore, some of the FISH steps involve harsh treatment of samples, and are likely to disrupt the floc structure. This study developed a FISH protocol for studying micro-organisms that are associated with particles and flocs. The results indicate that choice of a proper fluorochrome and labeling technique is a key step in reducing the background fluorescence and non-specific binding, and increasing the intensity of the probe signal. Compared to other fluorochromes tested, CY3 worked very well and enabled the observation of particles and debris in red and probe signal from microbes in yellow. Fixation, hybridization, and washing steps disturbed the floc structure and particle-microbe association. Modifications to these steps were necessary, and were achieved by replacing centrifugation with filtration and employment of nylon filters. Microscope slides generated excellent quality images, but polycarbonate membrane filters performed better in preserving the floc structure.
Collapse
Affiliation(s)
- Banu Ormeci
- Department of Civil and Environmental Engineering, Carleton University, Ottawa, Ontario, Canada.
| | | |
Collapse
|
20
|
Cryptosporidium and Giardia spp. infections in humans, animals and the environment in Poland. Parasitol Res 2008; 104:1-17. [DOI: 10.1007/s00436-008-1179-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 08/27/2008] [Indexed: 10/21/2022]
|
21
|
Harkins KR, Harrigan K. Labeling of bacterial pathogens for flow cytometric detection and enumeration. ACTA ACUST UNITED AC 2008; Chapter 11:Unit 11.17. [PMID: 18770788 DOI: 10.1002/0471142956.cy1117s29] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Traditional uses of flow cytometry have been for research and diagnostic purposes, on mammalian cells. This unit focuses on using a flow cytometer for enumerating specific bacteria and parasites. Several different labeling methods are discussed, as well as how to set up a cytometer for detecting and enumerating bacteria. Labeling methods include direct detection with a primary fluorochrome-conjugated antibody and indirect labeling with an unconjugated primary and a fluorochrome-conjugated secondary antibody, as well as labeling with rRNA sequence-specific peptide nucleic-acid probes end-labeled with a fluorochrome. Data and methods throughout this unit focus on detection of Salmonella in clean matrices; however, pertinent information is also provided on using these methods to label other pathogens. The Commentary covers critical aspects of the protocols, and also includes information and suggestions on the application of these methods for testing in the food and pharmaceutical industries, as well as in environmental water testing.
Collapse
|
22
|
Boxell A, Hijjawi N, Monis P, Ryan U. Comparison of various staining methods for the detection of Cryptosporidium in cell-free culture. Exp Parasitol 2008; 120:67-72. [DOI: 10.1016/j.exppara.2008.04.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 04/28/2008] [Accepted: 04/29/2008] [Indexed: 11/28/2022]
|
23
|
Development of fluorescent in situ hybridization for Cryptosporidium detection reveals zoonotic and anthroponotic transmission of sporadic cryptosporidiosis in Sydney. J Microbiol Methods 2008; 75:535-9. [PMID: 18789979 DOI: 10.1016/j.mimet.2008.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Revised: 08/19/2008] [Accepted: 08/21/2008] [Indexed: 11/24/2022]
Abstract
Cryptosporidium is the most common non-viral cause of diarrhea worldwide. Of the 5 described species that contribute to the majority of human infections, C. parvum is of major interest due to its zoonotic potential. A species-specific fluorescence in situ hybridisation probe was designed to the variable region in the small subunit of the 18S rRNA of C. parvum and labeled with Cy3. Probe specificity was validated against a panel of 7 other Cryptosporidium spp. before it was applied to 33 human faecal samples positive for cryptosporidiosis which were obtained during the period from 2006-2007. Results were compared to PCR-RFLP targeting the 18S rDNA. FISH results revealed that 19 of the 33 isolates analysed were identified as C. parvum. Correlation of PCR-RFLP and FISH was statistically significant (P<0.05), resulting in a calculated correlation coefficient of 0.994. In this study, species identification by FISH and PCR-RFLP provided preliminary evidence to support both anthroponotic and zoonotic transmission of sporadic cases of cryptosporidiosis in the Sydney basin. In conclusion, FISH using a C. parvum-specific probe provided an alternative tool for accurate identification of zoonotic Cryptosporidium which will be applied in the future to both epidemiological and outbreak investigations.
Collapse
|
24
|
Lucy FE, Graczyk TK, Tamang L, Miraflor A, Minchin D. Biomonitoring of surface and coastal water for Cryptosporidium, Giardia, and human-virulent microsporidia using molluscan shellfish. Parasitol Res 2008; 103:1369-75. [DOI: 10.1007/s00436-008-1143-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 07/21/2008] [Indexed: 10/21/2022]
|
25
|
Bouzid M, Steverding D, Tyler KM. Detection and surveillance of waterborne protozoan parasites. Curr Opin Biotechnol 2008; 19:302-6. [PMID: 18524569 DOI: 10.1016/j.copbio.2008.05.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Revised: 05/02/2008] [Accepted: 05/05/2008] [Indexed: 11/29/2022]
Abstract
The majority of the world's population still live without access to healthy water and the contamination of drinking water with protozoan pathogens poses a serious threat to millions of people in the developing world. Even in the developed world periodic outbreaks of diarrhoeal diseases are caused by the protozoan parasites Cryptosporidium sp., Giardia duodenalis and Entamoeba histolytica. Thus, surveillance of drinking water is imperative to minimize such contaminations and ensure continuous supplies of healthy water world-wide. This article reviews the progress in technology for detection and surveillance of these important waterborne parasites.
Collapse
Affiliation(s)
- Maha Bouzid
- BioMedical Research Centre, School of Medicine, Health Policy and Practice, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | | | | |
Collapse
|
26
|
Robertson LJ, Gjerde B. Development and use of a pepsin digestion method for analysis of shellfish for Cryptosporidium oocysts and Giardia cysts. J Food Prot 2008; 71:959-66. [PMID: 18522030 DOI: 10.4315/0362-028x-71.5.959] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Investigation of shellfish for Cryptosporidium oocysts and Giardia cysts is of public health interest because shellfish may concentrate these pathogens in their bodies, and because shellfish are frequently eaten raw or lightly cooked. To date, the methods used for the analysis of shellfish for these parasites are based on those originally designed for water concentrates or fecal samples; the reported recovery efficiencies are frequently relatively low and the amount of sample examined is small. Here, we describe the development and use of a pepsin digestion method for analyzing shellfish samples for these parasites. The conditions of the isolation method did not affect subsequent parasite detection by immunofluorescent antibody test, and allowed examination of 3-g samples of shellfish homogenate, with recovery efficiencies from blue mussel homogenates of between 70 and 80%, and similar recoveries from horse mussel and oyster homogenates. Although exposure of the parasites to the conditions used in the technique affected their viability, as assessed by vital dyes, the maximum reduction in viability after 1-h incubation in digestion solution was 20%. In a preliminary survey of shellfish collected from the Norwegian coast, Cryptosporidium oocysts were detected in blue mussel homogenates in 6 (43%) of 14 batches and Giardia cysts in 7 (50%) of these batches. However, this relatively high occurrence, compared with other surveys, may be due to the higher recovery efficiency of the new method, and the relatively large sample size analyzed. A more comprehensive study of the occurrence of these parasites in shellfish would be of pertinence to the Norwegian shellfish industry.
Collapse
Affiliation(s)
- L J Robertson
- Parasitology Laboratory, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, 0033 Oslo, Norway.
| | | |
Collapse
|
27
|
Jex AR, Smith HV, Monis PT, Campbell BE, Gasser RB. Cryptosporidium--biotechnological advances in the detection, diagnosis and analysis of genetic variation. Biotechnol Adv 2008; 26:304-17. [PMID: 18430539 DOI: 10.1016/j.biotechadv.2008.02.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 01/29/2008] [Accepted: 02/14/2008] [Indexed: 11/19/2022]
Abstract
Cryptosporidiosis is predominantly a gastrointestinal disease of humans and other animals, caused by various species of protozoan parasites representing the genus Cryptosporidium. This disease, transmitted mainly via the faecal-oral route (in water or food), is of major socioeconomic importance worldwide. The diagnosis and genetic characterization of the different species and population variants (usually recognised as "genotypes" or "subgenotypes") of Cryptosporidium is central to the prevention, surveillance and control of cryptosporidiosis, particularly given that there is presently no broadly applicable treatment regimen for this disease. Although traditional phenotypic techniques have had major limitations in the specific diagnosis of cryptosporidiosis, there have been major advances in the development of molecular analytical and diagnostic tools. This article provides a concise account of Cryptosporidium and cryptosporidiosis, and focuses mainly on recent advances in nucleic acid-based approaches for the diagnosis of cryptosporidiosis and analysis of genetic variation within and among species of Cryptosporidium. These advances represent a significant step toward an improved understanding of the epidemiology as well as the prevention and control of cryptosporidiosis.
Collapse
Affiliation(s)
- A R Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia.
| | | | | | | | | |
Collapse
|
28
|
Roberts JD, Silbergeld EK, Graczyk T. A probabilistic risk assessment of Cryptosporidium exposure among Baltimore urban anglers. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1568-76. [PMID: 17710616 DOI: 10.1080/15287390701384791] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In some urban settings, recreational fishing in industrialized waterways may pose a substantial health risk due to the presence of pathogenic microbes such as Cryptosporidium, a pathogen that produces a moderate to fatal gastrointestinal illness in humans. This pilot study examined the risk of exposure to Cryptosporidium based on fish samples and hand wash samples taken from urban anglers. Information regarding fishing frequency and consumption were also collected through an interview questionnaire to further characterize this risk. There were a total of 56 anglers interviewed and 46 fish and hand wash samples collected (18 hand wash samples and 28 fish samples). It was determined that the mean probability of infection using the U.S. Environmental Protection Agency's (EPA) dose-response model for Cryptosporidium and the fish and hand wash samples was 0.11 and 0.81, respectively. Among the positive fish samples, this mean probability was found to be 0.41. Depending on a variety of confounding factors, such as immunity, pre-existing illnesses and other host specific factors, this probability indicated that on average 1 to 8 out of 10 anglers could become infected. The current fish consumption advisories in Maryland and elsewhere provide no apparent information in regard to any microbiological contaminant. This pilot study provided data for possible modifications and improvements to be made to policy and risk communication regarding the potential health risks due to Cryptosporidium exposure from fishing.
Collapse
|
29
|
Robertson LJ, Gjerde BK. Cryptosporidium oocysts: challenging adversaries? Trends Parasitol 2007; 23:344-7. [PMID: 17581791 DOI: 10.1016/j.pt.2007.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 04/26/2007] [Accepted: 06/04/2007] [Indexed: 11/27/2022]
Abstract
A recent review by Brendon King and Paul Monis once again puts Cryptosporidium oocysts under the spotlight. Why is this tough transmission stage so troublesome now? And are future environments likely to assist or hinder its apparent ubiquity? Here, we explore further the fascination and challenge engendered by this parasite transmission stage.
Collapse
Affiliation(s)
- Lucy J Robertson
- Parasitology Laboratory, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, PO Box 8146 Dep., 0033 Oslo, Norway.
| | | |
Collapse
|
30
|
Taguchi T, Shinozaki Y, Takeyama H, Haraguchi S, Yoshino M, Kaneko M, Ishimori Y, Matsunaga T. Direct counting of Cryptosporidium parvum oocysts using fluorescence in situ hybridization on a membrane filter. J Microbiol Methods 2006; 67:373-80. [PMID: 16793153 DOI: 10.1016/j.mimet.2006.04.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 03/30/2006] [Accepted: 04/18/2006] [Indexed: 10/24/2022]
Abstract
This report describes the development of a direct and rapid detection method for the pathogenic protozoan, Cryptosporidium parvum, from environmental water samples using fluorescence in situ hybridization (FISH) on a membrane filter. The hydrophilic polytetrafluoroethylene (PTFE) membrane filter with FISH-stained oocysts yielded the highest signal to noise (S/N) ratio of the different membrane filters tested. PTFE membranes retained 98.8+/-0.4% of the concentrated oocysts after washing, simultaneous permeabilization and fixation with a hot ethanol solution, and hybridization with a fluorescently labeled oligonucleotide probe. This procedure eliminates subsequent time-consuming recovery steps that often result in a loss of the actual oocysts in a given environmental water sample. Furthermore, C. parvum was successfully distinguished from Cryptosporidium muris and other species in environmental water samples with the addition of formamide into the hybridization solution. In tap water samples, the S/N ratio was heightened by washing the membrane filter prior to FISH with a 1 M HCl solution in order to reduce the large amounts of impurities and background fluorescence from the non-specific adsorption of the fluorescently labeled oligonucleotide probe.
Collapse
Affiliation(s)
- Tomoyuki Taguchi
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Slodkowicz-Kowalska A, Graczyk TK, Tamang L, Girouard AS, Majewska AC. Asymptomatic Enterocytozoon bieneusi microsporidiosis in captive mammals. Parasitol Res 2006; 100:505-9. [PMID: 17016723 DOI: 10.1007/s00436-006-0303-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 08/07/2006] [Indexed: 10/24/2022]
Abstract
Human microsporidiosis, a serious disease of immunocompetent and immunosuppressed people, can be due to zoonotic transmission of microsporidian spores. A survey utilizing chromotrope 2R stain and fluorescent in situ hybridization techniques for testing feces from 193 captive mammals demonstrated that 3 animals (1.6%) shed Encephalitozoon bieneusi spores. These include two critically endangered species (i.e., black lemurs, Eulemur macaco flavifrons; and Visayan warty pig, Sus cebifrons negrinus) and a threatened species (mongoose lemur, Eulemur mongoz). The concentration of spores varied from 2.7 x 10(5) to 5.7 x 10(5)/g of feces, and all infections were asymptomatic. The study demonstrates that E. bieneusi spores can originate from captive animals, which is of particular epidemiologic importance because the close containment of zoological gardens can facilitate pathogen spread to other animals and also to people such as zoo personnel and visitors.
Collapse
Affiliation(s)
- Anna Slodkowicz-Kowalska
- Department of Biology and Medical Parasitology, Poznan University of Medical Sciences, Poznan, Poland
| | | | | | | | | |
Collapse
|
32
|
Graczyk TK, Lewis EJ, Glass G, Dasilva AJ, Tamang L, Girouard AS, Curriero FC. Quantitative assessment of viable Cryptosporidium parvum load in commercial oysters (Crassostrea virginica) in the Chesapeake Bay. Parasitol Res 2006; 100:247-53. [PMID: 16896650 DOI: 10.1007/s00436-006-0261-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Accepted: 06/08/2006] [Indexed: 11/30/2022]
Abstract
The epidemiological importance of increasing reports worldwide on Cryptosporidium contamination of oysters remains unknown in relation to foodborne cryptosporidiosis. Thirty market-size oysters (Crassostrea virginica), collected from each of 53 commercial harvesting sites in Chesapeake Bay, MD, were quantitatively tested in groups of six for Cryptosporidium sp. oocysts by immunofluorescent antibody (IFA). After IFA analysis, the samples were retrospectively retested for viable Cryptosporidium parvum oocysts by combined fluorescent in situ hybridization (FISH) and IFA. The mean cumulative numbers of Cryptosporidium sp. oocysts in six oysters (overall, 42.1+/-4.1) were significantly higher than in the numbers of viable C. parvum oocysts (overall, 28.0+/-2.9). Of 265 oyster groups, 221 (83.4%) contained viable C. parvum oocysts, and overall, from 10-32% (mean, 23%) of the total viable oocysts were identified in the hemolymph as distinct from gill washings. The amount of viable C. parvum oocysts was not related to oyster size or to the level of fecal coliforms at the sampling site. This study demonstrated that, although oysters are frequently contaminated with oocysts, the levels of viable oocysts may be too low to cause infection in healthy individuals. FISH assay for identification can be retrospectively applied to properly stored samples.
Collapse
Affiliation(s)
- Thaddeus K Graczyk
- Department of Environmental Health Sciences, Division of Environmental Health Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
| | | | | | | | | | | | | |
Collapse
|
33
|
Nocker A, Camper AK. Selective removal of DNA from dead cells of mixed bacterial communities by use of ethidium monoazide. Appl Environ Microbiol 2006; 72:1997-2004. [PMID: 16517648 PMCID: PMC1393219 DOI: 10.1128/aem.72.3.1997-2004.2006] [Citation(s) in RCA: 216] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distinction between viable and dead bacterial cells poses a major challenge in microbial diagnostics. Due to the persistence of DNA in the environment after cells have lost viability, DNA-based quantification methods overestimate the number of viable cells in mixed populations or even lead to false-positive results in the absence of viable cells. On the other hand, RNA-based diagnostic methods, which circumvent this problem, are technically demanding and suffer from some drawbacks. A promising and easy-to-use alternative utilizing the DNA-intercalating dye ethidium monoazide bromide (EMA) was published recently. This chemical is known to penetrate only into "dead" cells with compromised cell membrane integrity. Subsequent photoinduced cross-linking was reported to inhibit PCR amplification of DNA from dead cells. We provide evidence here that in addition to inhibition of amplification, most of the DNA from dead cells is actually lost during the DNA extraction procedure, probably together with cell debris which goes into the pellet fraction. Exposure of bacteria to increasing stress and higher proportions of dead cells in defined populations led to increasing loss of genomic DNA. Experiments were performed using Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium as model pathogens and using real-time PCR for their quantification. Results showed that EMA treatment of mixed populations of these two species provides a valuable tool for selective removal of DNA of nonviable cells by using conventional extraction protocols. Furthermore, we provide evidence that prior to denaturing gradient gel electrophoresis, EMA treatment of a mature mixed-population drinking-water biofilm containing a substantial proportion of dead cells can result in community fingerprints dramatically different from those for an untreated biofilm. The interpretation of such fingerprints can have important implications in the field of microbial ecology.
Collapse
Affiliation(s)
- Andreas Nocker
- Center for Biofilm Engineering, 366 EPS Building, P.O. Box 173980, Montana State University, Bozeman, MT 59717-3980, USA.
| | | |
Collapse
|
34
|
Zhang Q, Zhu L, Feng H, Ang S, Chau FS, Liu WT. Microbial detection in microfluidic devices through dual staining of quantum dots-labeled immunoassay and RNA hybridization. Anal Chim Acta 2006; 556:171-7. [PMID: 17723345 DOI: 10.1016/j.aca.2005.07.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 07/02/2005] [Accepted: 07/06/2005] [Indexed: 11/28/2022]
Abstract
This paper reported the development of a microfludic device for the rapid detection of viable and nonviable microbial cells through dual labeling by fluorescent in situ hybridization (FISH) and quantum dots (QDs)-labeled immunofluorescent assay (IFA). The coin sized device consists of a microchannel and filtering pillars (gap=1-2 microm) and was demonstrated to effectively trap and concentrate microbial cells (i.e. Giardia lamblia). After sample injection, FISH probe solution and QDs-labeled antibody solution were sequentially pumped into the device to accelerate the fluorescent labeling reactions at optimized flow rates (i.e. 1 and 20 microL/min, respectively). After 2 min washing for each assay, the whole process could be finished within 30 min, with minimum consumption of labeling reagents and superior fluorescent signal intensity. The choice of QDs 525 for IFA resulted in bright and stable fluorescent signal, with minimum interference with the Cy3 signal from FISH detection.
Collapse
Affiliation(s)
- Qing Zhang
- Division of Environmental Science and Engineering, National University of Singapore, Blk E1A, #07-03, Engineering Drive 2, Singapore 117576, Singapore
| | | | | | | | | | | |
Collapse
|
35
|
Power ML, Sangster NC, Slade MB, Veal DA. Patterns of Cryptosporidium oocyst shedding by eastern grey kangaroos inhabiting an Australian watershed. Appl Environ Microbiol 2005; 71:6159-64. [PMID: 16204534 PMCID: PMC1265986 DOI: 10.1128/aem.71.10.6159-6164.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The occurrence of Cryptosporidium oocysts in feces from a population of wild eastern grey kangaroos inhabiting a protected watershed in Sydney, Australia, was investigated. Over a 2-year period, Cryptosporidium oocysts were detected in 239 of the 3,557 (6.7%) eastern grey kangaroo fecal samples tested by using a combined immunomagnetic separation and flow cytometric technique. The prevalence of Cryptosporidium in this host population was estimated to range from 0.32% to 28.5%, with peaks occurring during the autumn months. Oocyst shedding intensity ranged from below 20 oocysts/g feces to 2.0 x 10(6) oocysts/g feces, and shedding did not appear to be associated with diarrhea. Although morphologically similar to the human-infective Cryptosporidium hominis and the Cryptosporidium parvum "bovine" genotype oocysts, the oocysts isolated from kangaroo feces were identified as the Cryptosporidium "marsupial" genotype I or "marsupial" genotype II. Kangaroos are the predominant large mammal inhabiting Australian watersheds and are potentially a significant source of Cryptosporidium contamination of drinking water reservoirs. However, this host population was predominantly shedding the marsupial-derived genotypes, which to date have been identified only in marsupial host species.
Collapse
Affiliation(s)
- Michelle L Power
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
| | | | | | | |
Collapse
|
36
|
Lemos V, Graczyk TK, Alves M, Lobo ML, Sousa MC, Antunes F, Matos O. Identification and determination of the viability of Giardia lamblia cysts and Cryptosporidium parvum and Cryptosporidium hominis oocysts in human fecal and water supply samples by fluorescent in situ hybridization (FISH) and monoclonal antibodies. Parasitol Res 2005; 98:48-53. [PMID: 16261356 DOI: 10.1007/s00436-005-0018-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 09/09/2005] [Indexed: 10/25/2022]
Abstract
In the present study, fluorescent in situ hybridization (FISH) and monoclonal antibodies (MAbs) were evaluated for species-specific detection and viability determination of Giardia lamblia, Cryptosporidium parvum, and Cryptosporidium hominis in human fecal and water supply samples. A total of 50 fecal human samples positive for G. lamblia cysts, 38 positive for C. parvum, and 23 positive for C. hominis were studied. Also, 18 water supply samples positive for Giardia spp. and Cryptosporidium spp. by the United States Environmental Protection Agency (USEPA) Method 1623 were studied by FISH and fluorescein isothiocyanate (FITC)-conjugated MAbs. Eighteen percent of the fecal samples parasitologically positive for G. lamblia presented viable and nonviable cysts, and 5% of those positive for Cryptosporidium spp. presented viable and nonviable oocysts. Of the 18 water supply samples analyzed, 6 (33%) presented Giardia spp. viable and nonviable cysts and 2 (11%) presented viable and nonviable Cryptosporidium spp. oocysts. G. lamblia identification was confirmed by polymerase chain reaction (PCR) and sequencing of the beta-giardin gene in the fecal and water samples found positive by FISH and FITC-conjugated MAbs. C. parvum and Cryptosporidium muris were identified, by PCR and sequencing of the small subunit of ribosomal RNA gene, in seven and one water samples, respectively. Our results confirm that this technique enables simultaneous visualization, species-specific identification, and viability determination of the organisms present in human fecal and water supply samples.
Collapse
Affiliation(s)
- Vanessa Lemos
- Unidade de Protozoários Oportunistas/VIH e Outras Protozooses, Unidade de Parasitologia e Microbiologia Médicas (UPMM), Instituto de Higiene e Medicina Tropical, Rua da Junqueira, 96, 1349-008 Lisbon, Portugal
| | | | | | | | | | | | | |
Collapse
|
37
|
Davies CM, Altavilla N, Krogh M, Ferguson CM, Deere DA, Ashbolt NJ. Environmental inactivation of Cryptosporidium oocysts in catchment soils. J Appl Microbiol 2005; 98:308-17. [PMID: 15659185 DOI: 10.1111/j.1365-2672.2004.02459.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To generate field-relevant inactivation rates for Cryptosporidium oocysts in soil that may serve as parameter values in models to predict the terrestrial fate and transport of oocysts in catchments. METHODS AND RESULTS The inactivation of Cryptosporidium oocysts in closed soil microcosms over time was monitored using fluorescence in situ hybridization (FISH) as an estimate of oocyst 'viability'. Inactivation rates for Cryptosporidium in two soils were determined under a range of temperature, moisture and biotic status regimes. Temperature and soil type emerged as significantly influential factors (P < 0.05) for Cryptosporidium inactivation. In particular, temperatures as high as 35 degrees C may result in enhanced inactivation. CONCLUSIONS When modelling the fate of Cryptosporidium oocysts in catchment soils, the use of inactivation rates that are appropriate for the specific catchment climate and soil types is essential. FISH was considered cost-effective and appropriate for determining oocyst inactivation rates in soil. SIGNIFICANCE AND IMPACT OF THE STUDY Previous models for predicting the fate of pathogens in catchments have either made nonvalidated assumptions regarding inactivation of Cryptosporidium in the terrestrial environment or have not considered it at all. Field-relevant inactivation data are presented, with significant implications for the management of catchments in warm temperate and tropical environments.
Collapse
Affiliation(s)
- C M Davies
- Centre for Water and Waste Technology, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW, Australia.
| | | | | | | | | | | |
Collapse
|
38
|
Di Giovanni GD, LeChevallier MW. Quantitative-PCR assessment of Cryptosporidium parvum cell culture infection. Appl Environ Microbiol 2005; 71:1495-500. [PMID: 15746352 PMCID: PMC1065146 DOI: 10.1128/aem.71.3.1495-1500.2005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A quantitative TaqMan PCR method was developed for assessing the Cryptosporidium parvum infection of in vitro cultivated human ileocecal adenocarcinoma (HCT-8) cell cultures. This method, termed cell culture quantitative sequence detection (CC-QSD), has numerous applications, several of which are presented. CC-QSD was used to investigate parasite infection in cell culture over time, the effects of oocyst treatment on infectivity and infectivity assessment of different C. parvum isolates. CC-QSD revealed that cell culture infection at 24 and 48 h postinoculation was approximately 20 and 60%, respectively, of the endpoint 72-h postinoculation infection. Evaluation of three different lots of C. parvum Iowa isolate oocysts revealed that the mean infection of 0.1 N HCl-treated oocysts was only 36% of the infection obtained with oocysts treated with acidified Hanks' balanced salt solution containing 1% trypsin. CC-QSD comparison of the C. parvum Iowa and TAMU isolates revealed significantly higher levels of infection for the TAMU isolate, which agrees with and supports previous human, animal, and cell culture studies. CC-QSD has the potential to aid in the optimization of Cryptosporidium cell culture methods and facilitate quantitative evaluation of cell culture infectivity experiments.
Collapse
|
39
|
Schweickert B, Moter A, Lefmann M, Göbel UB. Let them fly or light them up: matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and fluorescence in situ hybridization (FISH). APMIS 2005; 112:856-85. [PMID: 15638841 DOI: 10.1111/j.1600-0463.2004.apm11211-1210.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This review focuses on clinical bacteriology and by and large does not cover the detection of fungi, viruses or parasites. It discusses two completely different but complementary approaches that may either supplement or replace classic culture-based bacteriology. The latter view may appear provocative in the light of the actual market penetration of molecular genetic testing in clinical bacteriology. Despite its elegance, high specificity and sensitivity, molecular genetic diagnostics has not yet reached the majority of clinical laboratories. The reasons for this are manifold: Many microbiologists and medical technologists are more familiar with classical microbiological methods than with molecular biology techniques. Culture-based methods still represent the work horse of everyday routine. The number of available FDA-approved molecular genetic tests is limited and external quality control is still under development. Finally, it appears difficult to incorporate genetic testing in the routine laboratory setting due to the limited number of samples received or the lack of appropriate resources. However, financial and time constraints, particularly in hospitals as a consequence of budget cuts and reduced length of stay, lead to a demand for significantly shorter turnaround times that cannot be met by culture-dependent diagnosis. As a consequence, smaller laboratories that do not have the technical and personal equipment required for molecular genetic amplification techniques may adopt alternative methods such as fluorescence in situ hybridization (FISH) that combines easy-to-perform molecular hybridization with microscopy, a technique familiar to every microbiologist. FISH is hence one of the technologies presented here. For large hospital or reference laboratories with a high sample volume requiring massive parallel high-throughput testing we discuss matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) of nucleic acids, a technology that has evolved from the post-genome sequencing era, for high-throughput sequence variation analysis (1, 2).
Collapse
Affiliation(s)
- Birgitta Schweickert
- Institut für Mikrobiologie und Hygiene, Charité, Universitätsmedizin Berlin, Germany
| | | | | | | |
Collapse
|
40
|
Graczyk TK, Tamang L, Graczyk H. Human protozoan parasites in molluscan shellfish. ADVANCES IN FOOD AND NUTRITION RESEARCH 2005; 50:79-100. [PMID: 16263428 DOI: 10.1016/s1043-4526(05)50003-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Thaddeus K Graczyk
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | | | | |
Collapse
|
41
|
Lemarchand K, Masson L, Brousseau R. Molecular biology and DNA microarray technology for microbial quality monitoring of water. Crit Rev Microbiol 2004; 30:145-72. [PMID: 15490968 DOI: 10.1080/10408410490435142] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Public concern over polluted water is a major environmental issue worldwide. Microbial contamination of water arguably represents the most significant risk to human health on a global scale. An important challenge in modern water microbial quality monitoring is the rapid, specific, and sensitive detection of microbial indicators and waterborne pathogens. Presently, microbial tests are based essentially on time-consuming culture methods. Rapid microbiological analyses and detection of rare events in water systems are important challenges in water safety assessment since culture methods present serious limitations from both quantitative and qualitative points of view. To circumvent lengthy culture methods, newer enzymatic, immunological, and genetic methods are being developed as an alternative. DNA microarray technology is a new and promising tool that allows the detection of several hundred or even thousands DNA sequences simultaneously. Recent advances in sample processing and DNA microarray technologies provide new perspectives to assess microbial water quality. The aims of this review are to (1) summarize what is currently known about microbial indicators, (2) describe the most important waterborne pathogens, (3) present molecular methods used to monitor the presence of pathogens in water, and (4) show the potential of DNA microarrays in water quality monitoring.
Collapse
Affiliation(s)
- Karine Lemarchand
- National Research Council of Canada, Biotechnology Research Institute, Montreal, Quebec, Canada
| | | | | |
Collapse
|
42
|
Szostakowska B, Kruminis-Lozowska W, Racewicz M, Knight R, Tamang L, Myjak P, Graczyk TK. Cryptosporidium parvum and Giardia lamblia recovered from flies on a cattle farm and in a landfill. Appl Environ Microbiol 2004; 70:3742-4. [PMID: 15184182 PMCID: PMC427780 DOI: 10.1128/aem.70.6.3742-3744.2004] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 03/04/2004] [Indexed: 11/20/2022] Open
Abstract
Filth flies associated with a cattle barn and a municipal landfill were tested positive by combined immunofluorescent antibody and fluorescent in situ hybridization for Cryptosporidium parvum and Giardia lamblia on their exoskeletons and in their guts. More pathogens were carried by flies from the cattle barn than from the landfill; 81% of C. parvum and 84% of G. lamblia pathogens were presumptively viable.
Collapse
Affiliation(s)
- Beata Szostakowska
- Department of Tropical Parasitology, Interfaculty Institute of Maritime and Tropical Medicine, Medical University of Gdansk, 81-519 Gdynia, Poland
| | | | | | | | | | | | | |
Collapse
|
43
|
Smith JJ, Gunasekera TS, Barardi CRM, Veal D, Vesey G. Determination of Cryptosporidium parvum oocyst viability by fluorescence in situ hybridization using a ribosomal RNA-directed probe. J Appl Microbiol 2004; 96:409-17. [PMID: 14723702 DOI: 10.1046/j.1365-2672.2004.02150.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Fluorescence in situ hybridization (FISH) has been proposed for species-specific detection, and viability determination of Cryptosporidium parvum oocysts. FISH-based viability determination depends on rRNA decay after loss of viability. We examined the effects of RNase(s) and RNase inhibitors on FISH of C. parvum. METHODS AND RESULTS FISH was performed using a 5'-Texas red-labelled DNA oligonucleotide probe at 1 pM microl(-1). Intact and heat-permeabilized oocysts were treated with 1-100 microg ml(-1) RNase. FISH of intact oocysts appeared unaffected by exogenous RNase if this was neutralized before permeabilization. FISH fluorescence of heat-killed oocysts stored in phosphate-buffered saline at room temperature decayed by 1/2 after 55 h, but remained detectable after 6 days. Addition of vanadyl ribonucleoside complex (VRC) extended rRNA half-life of heat-permeabilized oocysts to 155 h. CONCLUSIONS Extended rRNA half-life may result in viability overestimation using FISH. RNase pretreatment before FISH is recommended to destroy residual rRNA in recently killed oocysts. Incorporation of 1-10 mM l(-1) VRC before FISH permeabilization steps should neutralize RNase activity. SIGNIFICANCE AND IMPACT OF THE STUDY Elimination of FISH fluorescence of nonviable C. parvum is desirable. Use of RNase and VRC is suggested to reduce numbers of false-positive 'viable' oocysts.
Collapse
Affiliation(s)
- J J Smith
- Montana Microbiological Services, IIc., Bozeman, MT, USA.
| | | | | | | | | |
Collapse
|
44
|
Carey CM, Lee H, Trevors JT. Biology, persistence and detection of Cryptosporidium parvum and Cryptosporidium hominis oocyst. WATER RESEARCH 2004; 38:818-862. [PMID: 14769405 DOI: 10.1016/j.watres.2003.10.012] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2003] [Revised: 10/06/2003] [Accepted: 10/22/2003] [Indexed: 05/24/2023]
Abstract
Cryptosporidium parvum and Cryptosporidium hominis are obligate enteric protozoan parasites which infect the gastrointestinal tract of animals and humans. The mechanism(s) by which these parasites cause gastrointestinal distress in their hosts is not well understood. The risk of waterborne transmission of Cryptosporidium is a serious global issue in drinking water safety. Oocysts from these organisms are extremely robust, prevalent in source water supplies and capable of surviving in the environment for extended periods of time. Resistance to conventional water treatment by chlorination, lack of correlation with biological indicator microorganisms and the absence of adequate methods to detect the presence of infectious oocysts necessitates the development of consistent and effective means of parasite removal from the water supply. Additional research into improving water treatment and sewage treatment practices is needed, particularly in testing the efficiency of ozone in oocyst inactivation. Timely and efficient detection of infectious C. parvum and C. hominis oocysts in environmental samples requires the development of rapid and sensitive techniques for the concentration, purification and detection of these parasites. A major factor confounding proper detection remains the inability to adequately and efficiently concentrate oocysts from environmental samples, while limiting the presence of extraneous materials. Molecular-based techniques are the most promising methods for the sensitive and accurate detection of C. parvum and C. hominis. With the availability of numerous target sequences, RT-PCR will likely emerge as an important method to assess oocyst viability. In addition, a multiplex PCR for the simultaneous detection of C. parvum, C. hominis and other waterborne pathogens such as Giardia lamblia would greatly benefit the water industry and protect human health.
Collapse
Affiliation(s)
- C M Carey
- Department of Environmental Biology, University of Guelph, Guelph, Ont, Canada N1G 2W1
| | | | | |
Collapse
|
45
|
Fontaine M, Guillot E. Study of 18S rRNA and rDNA stability by real-time RT-PCR in heat-inactivatedCryptosporidium parvumoocysts. FEMS Microbiol Lett 2003; 226:237-43. [PMID: 14553917 DOI: 10.1016/s0378-1097(03)00538-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The public health problem posed by Cryptosporidium parvum has led the water supply industry to develop analytical tools for detecting viable oocysts in water. In this study, we report on a TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR) method that targets and quantifies C. parvum 18S rRNA. To study the suitability of 18S rRNA as an indicator of Cryptosporidium oocyst viability, the stability of 18S rRNA and rDNA was monitored by real-time RT-PCR following various Cryptosporidium heat treatments. Decay of 18S rRNA was first observed after a 20-min treatment of C. parvum oocysts at 95 degrees C and was still detectable after 4 h. In contrast, rDNA was more heat resistant. The stability of 18S rRNA and rDNA was also studied after oocyst lysis by thermal shocks in the presence and absence of Chelex-100. In the former case, both rRNA and rDNA were degraded whereas in the presence of Chelex-100 both molecules were protected from heat degradation and were still detected after 4 h at 95 degrees C following thermal shocks. Our results indicate that 18S rRNA detection may not be directly associated with viability following heat inactivation of Cryptosporidium oocysts even if in all the experiments 18S rRNA was less stable than rDNA.
Collapse
Affiliation(s)
- Melanie Fontaine
- Suez-Environnement Local Services, CIRSEE, 38 Avenue du Président Wilson, 78230 Le Pecq, France.
| | | |
Collapse
|
46
|
Aguilar ZP, Fritsch I. Immobilized Enzyme-Linked DNA-Hybridization Assay with Electrochemical Detection forCryptosporidiumparvumhsp70 mRNA. Anal Chem 2003; 75:3890-7. [PMID: 14572058 DOI: 10.1021/ac026211z] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An electrochemical enzyme-linked immobilized DNA-hybridization assay for the detection of Cryptosporidium parvum in water has been developed. The target molecule was a 121-nucleotide sequence from the C. parvum heat shock protein 70 (hsp70 mRNA from U71181 gene). This analyte offers the possibility of distinguishing dead from live oocysts. The assay involves covalent attachment of a primary DNA probe via its 5'-amine-terminus to self-assembled monolayers of mercaptoundecanoic acid to a gold surface. The primary DNA probe was used to capture the target (sequence 1039-1082 of U71181 gene for the mRNA), by hybridization to a 20-base complementary sequence on the target (at sequence 1063-1082). A secondary DNA probe labeled with alkaline phosphatase (AP) was then hybridized to base sequence 1039-1062 on the target. p-Aminophenol, which is enzymatically generated by the immobilized AP from p-aminophenyl phosphate (PAPP), is detected using electrochemistry. The peak current of cyclic voltammograms from a PAPP solution, in which gold-coated silicon wafer modified with the complete assembly of the assay components was incubated, is linear with concentration of the target (5-50 microg/mL, where P1 and P2-AP concentrations are 50 microg/mL). A detection limit of 2 microg/mL (or 146 nM) of the DNA target was obtained. Cross-reactivity tests showed high selectivity for heat-shocked C. parvum. No signal was obtained for either the synthetic DNA for hsp70 of Campylobacter lari, Escherichia coli, Giardia lamblia, Salmonella typhimurium, and Listeria monocytogenes or for the products of heat-shocked whole organisms of E. coli, G. lamblia, Staphylococcus aureus, and Cryptosporidium muris.
Collapse
Affiliation(s)
- Zoraida P Aguilar
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA.
| | | |
Collapse
|
47
|
Yokouchi H, Takeyama H, Miyashita H, Maruyama T, Matsunaga T. In situ identification of symbiotic dinoflagellates, the genus Symbiodinium with fluorescence-labeled rRNA-targeted oligonucleotide probes. J Microbiol Methods 2003; 53:327-34. [PMID: 12689710 DOI: 10.1016/s0167-7012(02)00250-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Fluorescence in situ hybridization has been used for the identification and analysis of populations of the dinoflagellate Symbiodinium that lives symbiotically in marine invertebrates. Conditions for in situ hybridization of Symbiodinium were optimized and used to identify the clade to which the isolate belongs using specific probes. The optimized in situ hybridization procedure used a combination of chlorophyll removal and permeabilization with hot ethanol. Incubation of the cells in 50% ethanol at 80 degrees C for 20 min rendered the cell wall permeable to Cy3-labeled probes. Symbiodinium clade-specific probes were designed based on 18S rRNA sequences. Symbiodinium A, B and C were distinguished by in situ hybridization with the specific probes SymA, SymB and SymC, respectively. The hybridization results using clade-specific probes corresponded with results obtained using restriction fragment length polymorphism (RFLP) analysis. Symbiodinium isolated from jellyfish Cassiopea sp. and sea anemone Aiptasia sp. were classified as belonging to clades A and B using the FISH procedure established in this study.
Collapse
Affiliation(s)
- Hiroko Yokouchi
- Department of Biotechnology, Tokyo University of Agriculture and Technology 2-24-16, Naka-cho, Koganei, Japan
| | | | | | | | | |
Collapse
|
48
|
Tsushima Y, Karanis P, Kamada T, Xuan X, Makala LHC, Tohya Y, Akashi H, Nagasawa H. Viability and infectivity of Cryptosporidium parvum oocysts detected in river water in Hokkaido, Japan. J Vet Med Sci 2003; 65:585-9. [PMID: 12808210 DOI: 10.1292/jvms.65.585] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The viability and infectivity of Cryptosporidium parvum (C. parvum) oocysts, detected in water samples collected from river water in Hokkaido, were investigated using Severe Combined Immunodeficient (SCID) mice. The water samples collected from September 27 through October 10, 2001 by filtration using Cuno cartridge filters were purified and concentrated by the discontinuous centrifugal flotation method. From 1.2 x 10 (5) liters of the raw river water, approximately 2 x 10(4) oocysts were obtained and designated as Hokkaido river water 1 isolate (HRW-1). Oocyst identification was carried out using microscopic and immunological methods. Six 8-week-old female SCID mice were each inoculated orally with 1 x 10 (3) oocysts. Infection was successfully induced, resulting in fecal oocyst shedding. Oocysts were then maintained by sub-inoculation into SCID mice every 3 months. Infectivity was evaluated by making comparisons with two known C. parvum stocks, HNJ-1 and TK-1, which were bovine genotypes detected in fecal samples from a cryptosporidiosis patient and young cattle raised in Tokachi, Hokkaido respectively. The oocyst genotypes were determined from a small subunit ribosomal RNA (SSU-rRNA) gene by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) analysis. No significant differences were observed in the average number of oocysts per gram of feces (OPG) in any of the isolates. Our data indicates that the C. parvum oocysts detected in the sampled river water were of C. parvum genotype 2. Moreover, our data on the continued isolation, detection and identification of the C. parvum isolates is consistent with the available epidemiological data for the Tokachi area.
Collapse
Affiliation(s)
- Yoshinori Tsushima
- National Research Center for Protozoan Diseases, Obihiro University, Hokkaido, Japan
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Cox P, Fisher I, Kastl G, Jegatheesan V, Warnecke M, Angles M, Bustamante H, Chiffings T, Hawkins PR. Sydney 1998-lessons from a drinking water crisis. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/j.1551-8833.2003.tb10369.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
50
|
Ferrari BC, Veal D. Analysis-only detection of Giardia by combining immunomagnetic separation and two-color flow cytometry. Cytometry A 2003; 51:79-86. [PMID: 12541282 DOI: 10.1002/cyto.a.10009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Giardia is a protozoan parasite of concern to water utilities. Giardia detection relies on cyst isolation and confirmation with the use of fluorescence microscopy. It is of interest to develop a flow cytometric (FCM) method that reliably detects one cyst in 10 L of water. To date all available antibodies have targeted the same epitope on the cyst wall. To achieve a reliable method, two independent probes are required. METHODS Giardia cysts were spiked into a backwash water sample with and without prior hybridization to peptide nucleic acid (PNA) probes. Immunomagnetic separation (IMS) as a pre-enrichment step was compared with filtration of the water sample. Cysts were recovered with two-color FCM. Those cysts hybridized with PNA and fluorescein isothiocyanate (FITC) were dual stained with monoclonal antibody (mAb) conjugated to phycoerythrin (PE); those not hybridized to PNA were dual stained with mAb-FITC and mAb-PE. RESULTS A fourfold increase in fluorescent signal intensity was obtained when combining the mAb-PE and PNA probe compared with two-color antibody staining. When combined with IMS, Giardia was successfully identified by FCM, with no false positives detected. CONCLUSIONS Analysis-only FCM detection of Giardia in water is feasible. Further method development incorporating PNA probe hybridization after IMS is necessary.
Collapse
Affiliation(s)
- Belinda C Ferrari
- Centre for Fluorometric Applications in Biotechnology, School of Biological Sciences, Macquarie University, Sydney, Australia.
| | | |
Collapse
|