1
|
Singh S, Ahmed AI, Almansoori S, Alameri S, Adlan A, Odivilas G, Chattaway MA, Salem SB, Brudecki G, Elamin W. A narrative review of wastewater surveillance: pathogens of concern, applications, detection methods, and challenges. Front Public Health 2024; 12:1445961. [PMID: 39139672 PMCID: PMC11319304 DOI: 10.3389/fpubh.2024.1445961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Accepted: 07/18/2024] [Indexed: 08/15/2024] Open
Abstract
Introduction The emergence and resurgence of pathogens have led to significant global health challenges. Wastewater surveillance has historically been used to track water-borne or fecal-orally transmitted pathogens, providing a sensitive means of monitoring pathogens within a community. This technique offers a comprehensive, real-time, and cost-effective approach to disease surveillance, especially for diseases that are difficult to monitor through individual clinical screenings. Methods This narrative review examines the current state of knowledge on wastewater surveillance, emphasizing important findings and techniques used to detect potential pathogens from wastewater. It includes a review of literature on the detection methods, the pathogens of concern, and the challenges faced in the surveillance process. Results Wastewater surveillance has proven to be a powerful tool for early warning and timely intervention of infectious diseases. It can detect pathogens shed by asymptomatic and pre-symptomatic individuals, providing an accurate population-level view of disease transmission. The review highlights the applications of wastewater surveillance in tracking key pathogens of concern, such as gastrointestinal pathogens, respiratory pathogens, and viruses like SARS-CoV-2. Discussion The review discusses the benefits of wastewater surveillance in public health, particularly its role in enhancing existing systems for infectious disease surveillance. It also addresses the challenges faced, such as the need for improved detection methods and the management of antimicrobial resistance. The potential for wastewater surveillance to inform public health mitigation strategies and outbreak response protocols is emphasized. Conclusion Wastewater surveillance is a valuable tool in the fight against infectious diseases. It offers a unique perspective on the spread and evolution of pathogens, aiding in the prevention and control of disease epidemics. This review underscores the importance of continued research and development in this field to overcome current challenges and maximize the potential of wastewater surveillance in public health.
Collapse
Affiliation(s)
- Surabhi Singh
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Amina Ismail Ahmed
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Sumayya Almansoori
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Shaikha Alameri
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Ashraf Adlan
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Giovanni Odivilas
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Marie Anne Chattaway
- United Kingdom Health Security Agency, Gastrointestinal Bacteria Reference Laboratory, London, United Kingdom
| | - Samara Bin Salem
- Central Testing Laboratory, Abu Dhabi Quality and Conformity Council, Abu Dhabi, United Arab Emirates
| | - Grzegorz Brudecki
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| | - Wael Elamin
- Microbiology Lab, Reference and Surveillance Intelligence Department, Abu Dhabi, United Arab Emirates
| |
Collapse
|
2
|
Fradette MS, Culley AI, Charette SJ. Detection of Cryptosporidium spp. and Giardia spp. in Environmental Water Samples: A Journey into the Past and New Perspectives. Microorganisms 2022; 10:microorganisms10061175. [PMID: 35744692 PMCID: PMC9228427 DOI: 10.3390/microorganisms10061175] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/03/2022] [Accepted: 06/04/2022] [Indexed: 01/27/2023] Open
Abstract
Among the major issues linked with producing safe water for consumption is the presence of the parasitic protozoa Cryptosporidium spp. and Giardia spp. Since they are both responsible for gastrointestinal illnesses that can be waterborne, their monitoring is crucial, especially in water sources feeding treatment plants. Although their discovery was made in the early 1900s and even before, it was only in 1999 that the U.S. Environmental Protection Agency (EPA) published a standardized protocol for the detection of these parasites, modified and named today the U.S. EPA 1623.1 Method. It involves the flow-through filtration of a large volume of the water of interest, the elution of the biological material retained on the filter, the purification of the (oo)cysts, and the detection by immunofluorescence of the target parasites. Since the 1990s, several molecular-biology-based techniques were also developed to detect Cryptosporidium and Giardia cells from environmental or clinical samples. The application of U.S. EPA 1623.1 as well as numerous biomolecular methods are reviewed in this article, and their advantages and disadvantages are discussed guiding the readers, such as graduate students, researchers, drinking water managers, epidemiologists, and public health specialists, through the ever-expanding number of techniques available in the literature for the detection of Cryptosporidium spp. and Giardia spp. in water.
Collapse
Affiliation(s)
- Marie-Stéphanie Fradette
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; (A.I.C.); (S.J.C.)
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et Génie, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Aménagement et Développement du Territoire (CRAD), Université Laval, Québec City, QC G1V 0A6, Canada
- Correspondence:
| | - Alexander I. Culley
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; (A.I.C.); (S.J.C.)
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et Génie, Université Laval, Québec City, QC G1V 0A6, Canada
- Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Steve J. Charette
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, QC G1V 0A6, Canada; (A.I.C.); (S.J.C.)
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Faculté des Sciences et Génie, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec City, QC G1V 0A6, Canada
| |
Collapse
|
3
|
Luqman M, Awan MUF, Muhammad S, Daud S, Yousafzai A, Arooj F. Microbial pollution in inland recreational freshwaters of Quetta, Pakistan: an initial report. JOURNAL OF WATER AND HEALTH 2022; 20:575-588. [PMID: 35350009 DOI: 10.2166/wh.2022.291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Parasitic contamination of surface waters, especially recreational waters, is a serious problem for under-developed nations like Pakistan, where numerous outbreaks of parasitic diseases are reported each year. In the current study, parasitic presence in two surface waters (Hanna Lake and Wali-Tangi Dam) of Quetta was monitored quarterly for 1 year. The methodology involved the pre-concentration of the water samples and the subsequent preparation for the microscopic search of parasites. Physico-chemical and bacteriological variables were also studied. Wet staining, modified Trichrome staining, and modified acid-fast staining methods were used to identify various parasitic forms (cysts, oocysts, eggs, trophozoites). Collectively 11 parasitic elements (10 in Lake and 8 in Dam) belonging to 10 species were recorded, many of which are potential human pathogens. The species identified include Trichomonas sp., Isospora sp., Balantidium coli, Cryptosporidium sp., Entamoeba spp., amoebas, Microsporidium sp., Endolimax nana, Ascaris lumbricoides, and Giardia spp. Parasitic contamination remained persistent in both locations throughout the year independent of physico-chemical parameters (temperature, EC, pH, turbidity, and DO) and bacterial concentration of water. Reliance on bacterial presence for monitoring of recreational waters can be a risk for tourists. Entamoeba spp. and A. lumbricoides may be used for surface water monitoring in these waters.
Collapse
Affiliation(s)
- Muhammad Luqman
- Department of Environment Sciences, University of Veterinary and Animal Sciences, Outfall Road, Lahore, Pakistan E-mail:
| | | | - Sohaib Muhammad
- Department of Botany, Government College University, Kachehry Road, Lahore, Pakistan
| | - Shakeela Daud
- Department of Biotechnology, BUITEMS, Baleli Road, Quetta, Pakistan
| | - Asma Yousafzai
- Department of Biotechnology, BUITEMS, Baleli Road, Quetta, Pakistan
| | - Fariha Arooj
- Department of Environment Sciences, University of Veterinary and Animal Sciences, Outfall Road, Lahore, Pakistan E-mail:
| |
Collapse
|
4
|
Zahedi A, Monis P, Deere D, Ryan U. Wastewater-based epidemiology-surveillance and early detection of waterborne pathogens with a focus on SARS-CoV-2, Cryptosporidium and Giardia. Parasitol Res 2021; 120:4167-4188. [PMID: 33409629 PMCID: PMC7787619 DOI: 10.1007/s00436-020-07023-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/14/2020] [Indexed: 12/21/2022]
Abstract
Waterborne diseases are a major global problem, resulting in high morbidity and mortality, and massive economic costs. The ability to rapidly and reliably detect and monitor the spread of waterborne diseases is vital for early intervention and preventing more widespread disease outbreaks. Pathogens are, however, difficult to detect in water and are not practicably detectable at acceptable concentrations that need to be achieved in treated drinking water (which are of the order one per million litre). Furthermore, current clinical-based surveillance methods have many limitations such as the invasive nature of the testing and the challenges in testing large numbers of people. Wastewater-based epidemiology (WBE), which is based on the analysis of wastewater to monitor the emergence and spread of infectious disease at a population level, has received renewed attention in light of the current coronavirus disease 2019 (COVID-19) pandemic. The present review will focus on the application of WBE for the detection and surveillance of pathogens with a focus on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the waterborne protozoan parasites Cryptosporidium and Giardia. The review highlights the benefits and challenges of WBE and the future of this tool for community-wide infectious disease surveillance.
Collapse
Affiliation(s)
- Alireza Zahedi
- Harry Butler Institute, Murdoch University, Perth, Australia
| | - Paul Monis
- South Australian Water Corporation, Adelaide, Australia
| | - Daniel Deere
- Water Futures and Water Research Australia, Sydney, Australia
| | - Una Ryan
- Harry Butler Institute, Murdoch University, Perth, Australia.
| |
Collapse
|
5
|
Aghaindum AG, Atud AQ, Nadège OAT. Implications of soils around domestic water points in the spread of intestinal parasites in the city of Yaounde (Cameroon). JOURNAL OF WATER AND HEALTH 2019; 17:318-328. [PMID: 30942781 DOI: 10.2166/wh.2018.159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
To determine the role of soils in dissemination of enteric protozoan cysts and intestinal eggs and/or larvae of helminths, a study was carried out on muddy soils around springs and wells of six districts in Yaounde, Cameroon from February to July 2015. Protozoan cysts and helminth eggs and larvae were observed microscopically after concentration by standard scientific methods. Flagellated enteric protozoa cysts were detected at an average density of 245 ± 145 cysts/L for Giardia intestinalis, 308 ±190 cysts/L for Chilomastix mesnili, 105 ± 106 cysts/L for Enteromonas hominis and 96 ± 118 cysts/L for Retortamonas intestinalis. Cyst densities were higher during the short rainy season (277 ± 119 cysts/L) than in the short dry season (147 ± 60 cysts/L). The helminths identified were Ascaris sp., Enterobius sp., Necator americanus and/or Ancylostoma duodenale, Strongyloides sp., Taenia sp., Hymenolepis sp., Diphyllobothrium sp. and Fasciola sp. Size varied between 40 μm and 200 μm for eggs and between 100 μm and 600 μm for the larvae assessed. Densities of environmental forms of the helminths were also higher during the short rainy season (176 ± 77 agents/L) than during the short dry season (117 ± 49 agents/L). These results show that muddy soils could contribute to the contamination of wells and springs and should be considered in epidemiological studies of intestinal parasites.
Collapse
Affiliation(s)
- Ajeagah Gideon Aghaindum
- Laboratory of Hydrobiology and Environment, Faculty of Science, University of Yaounde I, P.O box, 812 Yaounde, Cameroun E-mail:
| | - Asi Quiggle Atud
- Laboratory of Hydrobiology and Environment, Faculty of Science, University of Yaounde I, P.O box, 812 Yaounde, Cameroun E-mail:
| | - Okoa Amougou Thérèse Nadège
- Laboratory of Hydrobiology and Environment, Faculty of Science, University of Yaounde I, P.O box, 812 Yaounde, Cameroun E-mail:
| |
Collapse
|
6
|
A modified PCR-RFLP method to determine genetic diversity of Giardia lamblia human isolates based on triosephosphate isomerase (TPI) gene. Acta Trop 2018; 186:58-62. [PMID: 29908169 DOI: 10.1016/j.actatropica.2018.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 06/10/2018] [Accepted: 06/11/2018] [Indexed: 11/22/2022]
Abstract
An infection of digestive system, Giardiasis, caused by tiny parasites called Giardia lamblia (also known Giardia intestinalis or Giardia duodenalis). Giardia sp. is the most common intestinal parasite of humans and other animals throughout the world. Isolates of G. lamblia are classified into eight assemblages based on isoenzyme and DNA analyses. Assemblages A and B infect humans and a broad range of other hosts. The purpose of this study was to genotype human isolates of G. lamblia by PCR-RFLP in Karaj city. 60 positive fecal samples of G. lamblia were collected. DNA extraction and amplification of TPI gene were successfully conducted by nested-PCR. Subsequently, all samples were positive. Sequencing on 5 samples was conducted to determine genetic differences. The presence of 2 genotypes of G. lamblia (A and B) was revealed by the alignment of the TPI sequences obtained with reference sequences. The results of RFLP technique show that 35 of 60 (58.3%) isolates belonged to assemblage A, and 17 of 60 (28.3%) belonged to assemblage B but 1(1.7%) sample was not determined. Whereas, 7 (11.6%) specimens were detected as mixed infections. The latter RFLP was carried out to identify subtypes.The final results were 100% (35/35) AII, 82.3% (14/17) BIII, and 17.7% (3/17) BIV. This study suggests that the modified RFLP method is favorably time saving and easily achievable and highly economical. Hence, the sub-assemblage AII might be dominant in Karaj city.
Collapse
|
7
|
Hamilton KA, Waso M, Reyneke B, Saeidi N, Levine A, Lalancette C, Besner MC, Khan W, Ahmed W. Cryptosporidium and Giardia in Wastewater and Surface Water Environments. JOURNAL OF ENVIRONMENTAL QUALITY 2018; 47:1006-1023. [PMID: 30272766 DOI: 10.2134/jeq2018.04.0132] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
and spp. are significant contributors to the global waterborne disease burden. Waterways used as sources of drinking water and for recreational activity can become contaminated through the introduction of fecal materials derived from humans and animals. Multiple studies have reported the occurence or concentrations of these pathogens in the environment. However, this information has not been comprehensively reviewed. Quantitative microbial risk assessment (QMRA) for and can be beneficial, but it often relies on the concentrations in environmental sources reported from the literature. A thorough literature review was conducted to develop an inventory of reported and concentrations in wastewater and surface water available in the literature. This information can be used to develop QMRA inputs. and (oo)cyst concentrations in untreated wastewater were up to 60,000 oocysts L and 100,000 cysts L, respectively. The maximum reported concentrations for and in surface water were 8400 oocysts L and 1000 cysts L, respectively. A summary of the factors for interpretation of concentration information including common quantification methods, survival and persistence, biofilm interactions, genotyping, and treatment removal is provided in this review. This information can help in identifying assumptions implicit in various QMRA parameters, thus providing the context and rationale to guide model formulation and application. Additionally, it can provide valuable information for water quality practitioners striving to meet the recreational water quality or treatment criteria. The goal is for the information provided in the current review to aid in developing source water protection and monitoring strategies that will minimize public health risks.
Collapse
|
8
|
Sahimin N, Douadi B, Yvonne Lim AL, Behnke JM, Mohd Zain SN. Distribution of Giardia duodenalis (Assemblages A and B) and Cryptosporidium parvum amongst migrant workers in Peninsular Malaysia. Acta Trop 2018; 182:178-184. [PMID: 29501402 DOI: 10.1016/j.actatropica.2018.02.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 02/08/2023]
Abstract
The influx of low skilled workers from socioeconomically deprived neighbouring countries to Malaysia has raised concerns about the transmission of communicable gastrointestinal diseases such as giardiasis and cryptosporidiosis to the local population. Therefore, a cross sectional study was conducted to investigate the prevalence of both diseases and the genetic diversity of these pathogens in the migrant population. Microscopic examination of faecal samples from 388 migrant workers involved in five working sectors were screened and 10.8% (n = 42) were found to be positive with Giardia spp. and 3.1% (n = 12) with Cryptosporidium spp. infections. PCR amplicons at the triosephosphate isomerase (tpi) gene were successfully obtained for Giardia duodenalis from 30 (30/388; 7.73%) samples with assemblages AII and B in 13 (13/30; 43.3%) and 17 (17/30; 56.7%) positive samples, respectively. Nine samples (9/388; 2.3%) were identified as Cryptosporidium parvum using PCR-RFLP analysis. Country of origin, duration of residence in Malaysia and working sectors significantly influenced G. duodenalis assemblage AII infections amongst the targeted population. Meanwhile, C. parvum infection was significantly associated with those working in the food service sector. Despite the low presence of pathogenic G. duodenalis and C. parvum in the study population, the results highlight the risk of anthroponotic foodborne and waterborne transmission and therefore call for implementation of control strategies through improvements in personal hygiene and sanitation standards.
Collapse
|
9
|
Prevalence and associated risk factors of Giardia duodenalis infection among school-going children in Nepal. Parasitol Res 2017; 117:287-293. [DOI: 10.1007/s00436-017-5706-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 11/29/2017] [Indexed: 11/26/2022]
|
10
|
Skhal D, Aboualchamat G, Al Mariri A, Al Nahhas S. Prevalence of Giardia duodenalis assemblages and sub-assemblages in symptomatic patients from Damascus city and its suburbs. INFECTION GENETICS AND EVOLUTION 2016; 47:155-160. [PMID: 27919804 DOI: 10.1016/j.meegid.2016.11.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 11/29/2016] [Accepted: 11/30/2016] [Indexed: 11/27/2022]
Abstract
Giardia duodenalis is one of the most important human enteric parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. However, there is limited information on the prevalent genetic variability of G. duodenalis in Syria. This study aimed to evaluate the predominance of G. duodenalis assemblages/sub-assemblages causing humans infection in the city of Damascus and its suburbs. 40 symptomatic giardiasis patients were recruited in this study. Fecal samples were genotyped using PCR/RFLP assay targeting the β-giardin and glutamate dehydrogenase (gdh) genes. HaeIII, BspL1 and RsaI restriction enzymes were used to differentiate between G. duodenalis assemblages/sub-assemblages. Our data showed that 65% of isolates were of assemblage A; 45% belonged to sub-assemblage AII and 20% to sub-assemblage AI. Assemblage B was detected in 27.5% of isolates; 12.5% fit in sub-assemblage BIV, 5% fit in sub-assemblage BIII and 10.5% fit in Discordant genotype BIII/BIV. Mixed genotypes (AII+BIII and AI+BIV) were identified in 3 isolates (7.5%). Significant correlation was found between Giardia AII sub-assemblage and weight loss symptom (P-value=0.05) as well as between contact with domestic animals (cats, P-value=0.027). Moreover, a significant correlation was found between sub-assemblage AI and livestock breeding (P-value=0.000). In conclusion genotyping of human Giardia duodenalis isolates suggests anthroponotic transmission for the route of infection in Damascus and its suburbs. Further studies are needed to screen a wide geographic areas in Syria and to estimate the prevalence of G. duodenalis infection in our population.
Collapse
Affiliation(s)
- Dania Skhal
- Department of Animal Biology, Faculty of Science, Damascus University, Damascus, Syria
| | - Ghalia Aboualchamat
- Department of Animal Biology, Faculty of Science, Damascus University, Damascus, Syria
| | - Ayman Al Mariri
- Atomic Energy Commission of Syria, Department of Molecular Biology and Biotechnology, Microbiology and Immunology Division, Syria
| | - Samar Al Nahhas
- Department of Animal Biology, Faculty of Science, Damascus University, Damascus, Syria.
| |
Collapse
|
11
|
Sahimin N, Lim YAL, Ariffin F, Behnke JM, Lewis JW, Mohd Zain SN. Migrant Workers in Malaysia: Current Implications of Sociodemographic and Environmental Characteristics in the Transmission of Intestinal Parasitic Infections. PLoS Negl Trop Dis 2016; 10:e0005110. [PMID: 27806046 PMCID: PMC5091761 DOI: 10.1371/journal.pntd.0005110] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 10/14/2016] [Indexed: 11/18/2022] Open
Abstract
A cross-sectional study of intestinal parasitic infections amongst migrant workers in Malaysia was conducted. A total of 388 workers were recruited from five sectors including manufacturing, construction, plantation, domestic and food services. The majority were recruited from Indonesia (n = 167, 43.3%), followed by Nepal (n = 81, 20.9%), Bangladesh (n = 70, 18%), India (n = 47, 12.1%) and Myanmar (n = 23, 5.9.2%). A total of four nematode species (Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms), one cestode (Hymenolepis nana) and three protozoan species (Entamoeba histolytica/dispar, Giardia sp. and Cryptosporidium spp.) were identified. High prevalence of infections with A. lumbricoides (43.3%) was recorded followed by hookworms (13.1%), E. histolytica/dispar (11.6%), Giardia sp. (10.8%), T. trichura (9.5%), Cryptosporodium spp. (3.1%), H. nana (1.8%) and E. vermicularis (0.5%). Infections were significantly influenced by socio-demographic (nationality), and environmental characteristics (length of working years in the country, employment sector and educational level). Up to 84.0% of migrant workers from Nepal and 83.0% from India were infected with intestinal parasites, with the ascarid nematode A. lumbricoides occurring in 72.8% of the Nepalese and 68.1% of the Indian population. In addition, workers with an employment history of less than a year or newly arrived in Malaysia were most likely to show high levels of infection as prevalence of workers infected with A. lumbricoides was reduced from 58.2% to 35.4% following a year's residence. These findings suggest that improvement is warranted in public health and should include mandatory medical screening upon entry into the country.
Collapse
Affiliation(s)
- Norhidayu Sahimin
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne A. L. Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Farnaza Ariffin
- Primary Care Medicine, Faculty of Medicine, University Teknologi Mara Sungai Buloh Campus, Selangor, Malaysia
| | - Jerzy M. Behnke
- School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom
| | - John W. Lewis
- School of Biological Sciences, University of London, Egham, Surrey, United Kingdom
| | - Siti Nursheena Mohd Zain
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
12
|
Stark D, Barratt J, Chan D, Ellis JT. Dientamoeba fragilis, the Neglected Trichomonad of the Human Bowel. Clin Microbiol Rev 2016; 29:553-80. [PMID: 27170141 PMCID: PMC4861990 DOI: 10.1128/cmr.00076-15] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome.
Collapse
Affiliation(s)
- Damien Stark
- Division of Microbiology, Sydpath, St Vincent's Hospital, Darlinghurst, NSW, Australia
| | - Joel Barratt
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
| | - Douglas Chan
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
| | - John T Ellis
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
| |
Collapse
|
13
|
Kumar T, Abd Majid MA, Onichandran S, Jaturas N, Andiappan H, Salibay CC, Tabo HAL, Tabo N, Dungca JZ, Tangpong J, Phiriyasamith S, Yuttayong B, Polseela R, Do BN, Sawangjaroen N, Tan TC, Lim YAL, Nissapatorn V. Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system. Infect Dis Poverty 2016; 5:3. [PMID: 26763230 PMCID: PMC4712598 DOI: 10.1186/s40249-016-0095-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 01/04/2016] [Indexed: 11/10/2022] Open
Abstract
Background Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays. Methods A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency’s methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays. Results Cryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993). Conclusion The presence of (oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries. Detection using qPCR is feasible for quantifying both pathogenic C. parvum and G. lamblia in large water samples.
Collapse
Affiliation(s)
- Thulasi Kumar
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohamad Azlan Abd Majid
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Subashini Onichandran
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Narong Jaturas
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Hemah Andiappan
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Cristina C Salibay
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Hazel A L Tabo
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Norbel Tabo
- Biological Science Department, College of Science and Computer Studies, De La Salle University-Dasmariñas, Dasmariñas, Philippines
| | - Julieta Z Dungca
- School of Science and Technology, Centro Escolar University, Manila, Philippines
| | - Jitbanjong Tangpong
- School of Allied Health Sciences and Public Health, Walailak University, Nakhon Si Thammarat, Thailand
| | | | - Boonyaorn Yuttayong
- Regional Medical Sciences Center, Department of Medical Sciences, Ministry of Public Health, Nakhon Ratchasima, Thailand
| | - Raxsina Polseela
- Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Binh Nhu Do
- Department of Parasitology, Faculty of Medicine, Vietnam Military Medical University, 160 Phung Hung Road, Phuc La Ward, Ha Dong District, Hanoi, Vietnam
| | - Nongyao Sawangjaroen
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Thailand
| | - Tian-Chye Tan
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne A L Lim
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Veeranoot Nissapatorn
- Department of Parasitology (Southeast Asia Water Team), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| |
Collapse
|
14
|
Ramírez-Castillo FY, Loera-Muro A, Jacques M, Garneau P, Avelar-González FJ, Harel J, Guerrero-Barrera AL. Waterborne pathogens: detection methods and challenges. Pathogens 2015; 4:307-34. [PMID: 26011827 PMCID: PMC4493476 DOI: 10.3390/pathogens4020307] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/08/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022] Open
Abstract
Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems’ infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health.
Collapse
Affiliation(s)
- Flor Yazmín Ramírez-Castillo
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
- Laboratorio de Ciencias Ambientales, Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
| | - Abraham Loera-Muro
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
| | - Mario Jacques
- Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada.
| | - Philippe Garneau
- Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada.
| | - Francisco Javier Avelar-González
- Laboratorio de Ciencias Ambientales, Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
| | - Josée Harel
- Centre de Recherche en Infectiologie Porcine et Avicole, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC J2S 7C6, Canada.
| | - Alma Lilián Guerrero-Barrera
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
| |
Collapse
|
15
|
Taran-Benshoshan M, Ofer N, Dalit VO, Aharoni A, Revhun M, Nitzan Y, Nasser AM. Cryptosporidium and Giardia removal by secondary and tertiary wastewater treatment. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2015; 50:1265-1273. [PMID: 26301853 DOI: 10.1080/10934529.2015.1055152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Wastewater disposal may be a source of environmental contamination by Cryptosporidium and Giardia. This study was conducted to evaluate the prevalence of Cryptosporidium oocysts and Giardia cysts in raw and treated wastewater effluents. A prevalence of 100% was demonstrated for Giardia cysts in raw wastewater, at a concentration range of 10 to 12,225 cysts L(-1), whereas the concentration of Cryptosporidium oocysts in raw wastewater was 4 to 125 oocysts L(-1). The removal of Giardia cysts by secondary and tertiary treatment processes was greater than those observed for Cryptosporidium oocysts and turbidity. Cryptosporidium and Giardia were present in 68.5% and 76% of the tertiary effluent samples, respectively, at an average concentration of 0.93 cysts L(-1) and 9.94 oocysts L(-1). A higher detection limit of Cryptosporidium oocysts in wastewater was observed for nested PCR as compared to immune fluorescent assay (IFA). C. hominis was found to be the dominant genotype in wastewater effluents followed by C. parvum and C. andersoni or C. muris. Giardia was more prevalent than Cryptosporidium in the studied community and treatment processes were more efficient for the removal of Giardia than Cryptosporidium. Zoonotic genotypes of Cryptosporidium were also present in the human community. To assess the public health significance of Cryptosporidium oocysts present in tertiary effluent, viability (infectivity) needs to be assessed.
Collapse
|
16
|
Koehler AV, Jex AR, Haydon SR, Stevens MA, Gasser RB. Giardia/giardiasis — A perspective on diagnostic and analytical tools. Biotechnol Adv 2014; 32:280-9. [DOI: 10.1016/j.biotechadv.2013.10.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 10/08/2013] [Accepted: 10/27/2013] [Indexed: 12/28/2022]
|
17
|
Botes M, de Kwaadsteniet M, Cloete TE. Application of quantitative PCR for the detection of microorganisms in water. Anal Bioanal Chem 2013; 405:91-108. [PMID: 23001336 PMCID: PMC7079929 DOI: 10.1007/s00216-012-6399-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/28/2012] [Accepted: 08/29/2012] [Indexed: 11/13/2022]
Abstract
The occurrence of microorganisms in water due to contamination is a health risk and control thereof is a necessity. Conventional detection methods may be misleading and do not provide rapid results allowing for immediate action. The quantitative polymerase chain reaction (qPCR) method has proven to be an effective tool to detect and quantify microorganisms in water within a few hours. Quantitative PCR assays have recently been developed for the detection of specific adeno- and polyomaviruses, bacteria and protozoa in different water sources. The technique is highly sensitive and able to detect low numbers of microorganisms. Quantitative PCR can be applied for microbial source tracking in water sources, to determine the efficiency of water and wastewater treatment plants and act as a tool for risk assessment. Different qPCR assays exist depending on whether an internal control is used or whether measurements are taken at the end of the PCR reaction (end-point qPCR) or in the exponential phase (real-time qPCR). Fluorescent probes are used in the PCR reaction to hybridise within the target sequence to generate a signal and, together with specialised systems, quantify the amount of PCR product. Quantitative reverse transcription polymerase chain reaction (q-RT-PCR) is a more sensitive technique that detects low copy number RNA and can be applied to detect, e.g. enteric viruses and viable microorganisms in water, and measure specific gene expression. There is, however, a need to standardise qPCR protocols if this technique is to be used as an analytical diagnostic tool for routine monitoring. This review focuses on the application of qPCR in the detection of microorganisms in water.
Collapse
Affiliation(s)
- Marelize Botes
- Department of Microbiology, University of Stellenbosch, Private Bag XI, Matieland 7602, Stellenbosch, Western Cape 7602, South Africa.
| | | | | |
Collapse
|
18
|
Nasser A, Vaizel-Ohayon D, Aharoni A, Revhun M. Prevalence and fate of giardia cysts in wastewater treatment plants. J Appl Microbiol 2012; 113:477-84. [DOI: 10.1111/j.1365-2672.2012.05335.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
19
|
Abstract
Microscopy still remains the gold standard procedure for the diagnosis of many protozoan infections in animals, but the specific identification requires skilled and experienced personnel. Immunoassays, detecting antibodies or specific protozoan antigens, have been developed but often lack sensitivity and specificity due to close relationship between many protozoa. Recent research has focussed almost exclusively on molecular based techniques for the identification and quantification of parasite DNA in samples. Opinion differ on most appropriate targets to use and there are very few diagnostic kits available making comparison between laboratories difficult. Future research needs to focus on robust, cheap field diagnostic assays.
Collapse
|
20
|
Júlio C, Vilares A, Oleastro M, Ferreira I, Gomes S, Monteiro L, Nunes B, Tenreiro R, Angelo H. Prevalence and risk factors for Giardia duodenalis infection among children: a case study in Portugal. Parasit Vectors 2012; 5:22. [PMID: 22284337 PMCID: PMC3275531 DOI: 10.1186/1756-3305-5-22] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 01/27/2012] [Indexed: 01/28/2023] Open
Abstract
Background Giardia duodenalis is a widespread parasite of mammalian species, including humans. The prevalence of this parasite in children residing in Portugal is currently unknown. This study intended to estimate G. duodenalis infection prevalence and identify possible associated risk factors in a healthy paediatric population living in the District of the Portuguese capital, Lisbon. Methods Between February 2002 and October 2008, 844 children were randomly selected at healthcare centres while attending the national vaccination program. A stool sample and a questionnaire with socio-demographic data were collected from each child. Giardia infection was diagnosed by direct examination of stools and antigen detection by ELISA. Results The population studied revealed a gender distribution of 52.8% male and 47.2% female. Age distribution was 47.4% between 0-5 years and 52.6% between 6-15 years. The prevalence of Giardia infection was 1.9% (16/844) when estimated by direct examination and increased to 6.8% (57/844) when ELISA results were added. The prevalence was higher among children aged 0-5 years (7.8%), than among older children (5.8%), and was similar among genders (6.9% in boys and 6.5% in girls). The following population-variables were shown to be associated risk factors for G. duodenalis infection: mother's educational level (odds ratio (OR)= 4.49; confidence interval (CI): 1.20-16.84), father's educational level (OR = 12.26; CI: 4.08-36.82), presence of Helicobacter pylori infection (OR = 1.82; CI: 1.05-3.15), living in houses with own drainage system (OR = 0.10; CI: 0.02-0.64) and reported household pet contact, especially with dogs (OR = 0.53; CI: 0.31-0.93). Conclusion The prevalence of giardiasis in asymptomatic children residing in the region of Lisbon is high. Several risk factors were associated with Giardia prevalence and highlight the importance of parents' education and sanitation conditions in the children's well being. The association between G. duodenalis and H. pylori seems an important issue deserving further investigation in order to promote prevention or treatment strategies.
Collapse
Affiliation(s)
- Cláudia Júlio
- National Institute of Health Dr. Ricardo Jorge, Department of Infectious Diseases, National Reference Laboratory for Gastrointestinal Infections, Av. Padre Cruz, Lisbon, Portugal.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Gajamange D, Yoon JM, Park KI. Development of a real-time PCR method for detection and quantification of the parasitic protozoan Perkinsus olseni. ACTA ACUST UNITED AC 2011. [DOI: 10.9710/kjm.2011.27.4.387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
22
|
Alonso JL, Amorós I, Cañigral I. Development and evaluation of a real-time PCR assay for quantification of Giardia and Cryptosporidium in sewage samples. Appl Microbiol Biotechnol 2011; 89:1203-11. [PMID: 21061006 DOI: 10.1007/s00253-010-2984-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 10/20/2010] [Accepted: 10/24/2010] [Indexed: 10/18/2022]
Abstract
Cryptosporidium and Giardia are major causes of diarrheal disease in humans worldwide and are major causes of protozoan waterborne diseases. Two DNA TaqMan PCR-based Giardia and Cryptosporidium methods targeting a 74-bp sequence of the β-giardin Giardia gene and a 151-bp sequence of the COWP Cryptosporidium gene, respectively, were used as models to compare two different LNA/DNA TaqMan probes to improve the detection limit in a real-time PCR assay. The LNA probes were the most sensitive resulting in 0.96 to 1.57 lower C t values than a DNA Giardia TaqMan probe and 0.56 to 2.21 lower than a DNA Cryptosporidium TaqMan probe. Evaluation of TaqMan Giardia and Cryptosporidium probes with LNA substitutions resulted in real-time PCR curves with an earlier C t values than conventional DNA TaqMan probes. In conclusion, the LNA probes could be useful for more sensitive detection limits.
Collapse
Affiliation(s)
- José L Alonso
- Instituto de Ingeniería del Agua y Medio Ambiente, Ciudad Politécnica de la Innovación, Ed. 8G, Acceso D, planta 2, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain.
| | | | | |
Collapse
|
23
|
Poyatos JM, Almecija MC, García-Mesa JJ, Muñio MM, Hontoria E, Torres JC, Osorio F. Advanced methods for the elimination of microorganisms in industrial treatments: potential applicability to wastewater reuse. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2011; 83:233-246. [PMID: 21466071 DOI: 10.2175/106143010x12780288628570] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Because of the growing need to eliminate undesirable microorganisms in different industrial treatments, mainly in the food and agricultural sector and the pharmaceutical industry, a number of increasingly effective systems for disinfection to eliminate microorganisms have been devised. This article analyzes different methods to eliminate and/or significantly reduce the number of microorganisms in industrial contexts and in environmental engineering. Although, in the past, thermal treatments had been used most frequently for microbial elimination, the method is costly and has the disadvantage of modifying the organoleptic and/or physicochemical properties of the food products. For this reason, new technologies rapidly are being developed, such as high-intensity pulsed electric fields, high-pressure systems, ultrasounds, and irradiation, which effectively eliminate microorganisms without deteriorating the properties of the product. These emerging technologies are potentially applicable in the field of environmental engineering.
Collapse
Affiliation(s)
- J M Poyatos
- Department of Civil Engineering, University of Granada, Spain
| | | | | | | | | | | | | |
Collapse
|
24
|
Venieri D, Chatzisymeon E, Gonzalo MS, Rosal R, Mantzavinos D. Inactivation of Enterococcus faecalis by TiO2-mediated UV and solar irradiation in water and wastewater: culture techniques never say the whole truth. Photochem Photobiol Sci 2011; 10:1744-50. [DOI: 10.1039/c1pp05198a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
25
|
Polley SD, Boadi S, Watson J, Curry A, Chiodini PL. Detection and species identification of microsporidial infections using SYBR Green real-time PCR. J Med Microbiol 2010; 60:459-466. [PMID: 21183599 DOI: 10.1099/jmm.0.026781-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diagnosis of microsporidial infections is routinely performed by light microscopy, with unequivocal non-molecular species identification achievable only through electron microscopy. This study describes a single SYBR Green real-time PCR assay for the simultaneous detection and species identification of such infections. This assay was highly sensitive, routinely detecting infections containing 400 parasites (g stool sample)(-1), whilst species identification was achieved by differential melt curves on a Corbett Life Science Rotor-Gene 3000. A modification of the QIAamp DNA tissue extraction protocol allowed the semi-automated extraction of DNA from stools for the routine diagnosis of microsporidial infection by real-time PCR. Of 168 stool samples routinely analysed for microsporidian spores, only five were positive by microscopy. By comparison, 17 were positive for microsporidial DNA by real-time analysis, comprising 14 Enterocytozoon bieneusi, one Encephalitozoon cuniculi and two separate Pleistophora species infections.
Collapse
Affiliation(s)
- Spencer D Polley
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, Mortimer Market, Capper Street, London WC1E 6JB, UK
| | - Samuel Boadi
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, Mortimer Market, Capper Street, London WC1E 6JB, UK
| | - Julie Watson
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, Mortimer Market, Capper Street, London WC1E 6JB, UK
| | - Alan Curry
- Health Protection Agency, Regional Microbiology Network, North West Regional Laboratory, PO Box 209, Clinical Sciences Building, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WZ, UK
| | - Peter L Chiodini
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
- Department of Clinical Parasitology, Hospital for Tropical Diseases, University College London Hospitals NHS Foundation Trust, Mortimer Market, Capper Street, London WC1E 6JB, UK
| |
Collapse
|
26
|
Moulin L, Richard F, Stefania S, Goulet M, Gosselin S, Gonçalves A, Rocher V, Paffoni C, Dumètre A. Contribution of treated wastewater to the microbiological quality of Seine River in Paris. WATER RESEARCH 2010; 44:5222-5231. [PMID: 20630555 DOI: 10.1016/j.watres.2010.06.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 05/26/2010] [Accepted: 06/15/2010] [Indexed: 05/29/2023]
Abstract
Urban part of Seine River serving as drinking water supply in Paris can be heavily contaminated by Cryptosporidium spp. and Giardia duodenalis. In the absence of agricultural practice in this highly urbanized area, we investigated herein the contribution of treated wastewater to the microbiological quality of this river focusing on these two parasites. Other microorganisms such as faecal bacterial indicators, enteroviruses and oocysts of Toxoplasma gondii were assessed concurrently. Raw wastewaters were heavily contaminated by Cryptosporidium and Giardia (oo)cysts, whereas concentrations of both protozoa in treated wastewater were lower. Treated wastewater, flowed into Seine River, had a parasite concentration closed to the one found along the river, in particular at the entry of a drinking water plant (DWP). Even if faecal bacteria were reliable indicators of a reduction in parasite concentrations during the wastewater treatment, they were not correlated to protozoal contamination of wastewater and river water. Oocysts of T. gondii were not found in both raw and treated wastewater, or in Seine River. Parasitic contamination was shown to be constant in the Seine River up to 40 km upstream Paris. Altogether, these results strongly suggest that treated wastewater does not contribute to the main parasitic contamination of the Seine River usually observed in this urbanized area.
Collapse
Affiliation(s)
- Laurent Moulin
- EAU DE PARIS, 144 Avenue Paul Vaillant-Couturier, 75014 Paris, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Girones R, Ferrús MA, Alonso JL, Rodriguez-Manzano J, Calgua B, Corrêa ADA, Hundesa A, Carratala A, Bofill-Mas S. Molecular detection of pathogens in water--the pros and cons of molecular techniques. WATER RESEARCH 2010; 44:4325-39. [PMID: 20619868 DOI: 10.1016/j.watres.2010.06.030] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 06/10/2010] [Accepted: 06/14/2010] [Indexed: 05/04/2023]
Abstract
Pollution of water by sewage and run-off from farms produces a serious public health problem in many countries. Viruses, along with bacteria and protozoa in the intestine or in urine are shed and transported through the sewer system. Even in highly industrialized countries, pathogens, including viruses, are prevalent throughout the environment. Molecular methods are used to monitor viral, bacterial, and protozoan pathogens, and to track pathogen- and source-specific markers in the environment. Molecular techniques, specifically polymerase chain reaction-based methods, provide sensitive, rapid, and quantitative analytical tools with which to study such pathogens, including new or emerging strains. These techniques are used to evaluate the microbiological quality of food and water, and to assess the efficiency of virus removal in drinking and wastewater treatment plants. The range of methods available for the application of molecular techniques has increased, and the costs involved have fallen. These developments have allowed the potential standardization and automation of certain techniques. In some cases they facilitate the identification, genotyping, enumeration, viability assessment, and source-tracking of human and animal contamination. Additionally, recent improvements in detection technologies have allowed the simultaneous detection of multiple targets in a single assay. However, the molecular techniques available today and those under development require further refinement in order to be standardized and applicable to a diversity of matrices. Water disinfection treatments may have an effect on the viability of pathogens and the numbers obtained by molecular techniques may overestimate the quantification of infectious microorganisms. The pros and cons of molecular techniques for the detection and quantification of pathogens in water are discussed.
Collapse
Affiliation(s)
- Rosina Girones
- Department of Microbiology, Faculty of Biology, University of Barcelona. Av. Diagonal 645, 08028 Barcelona, Spain.
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Genotyping of Giardia duodenalis cysts by new real-time PCR assays for detection of mixed infections in human samples. Appl Environ Microbiol 2010; 76:1895-901. [PMID: 20080999 DOI: 10.1128/aem.02305-09] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Of the seven genetic groups, or assemblages, currently recognized in the Giardia duodenalis species complex, only assemblages A and B are associated with human infection, but they also infect other mammals. Recent investigations have suggested the occurrence of genetic exchanges among isolates of G. duodenalis, and the application of assemblage-specific PCR has shown both assemblages A and B in a significant number of human infections. In this work, three real-time quantitative (qPCR) assays were developed to target the G. duodenalis triose phosphate isomerase, glutamate dehydrogenase, and open reading frame C4 sequences. Primers were designed to allow the specific amplification of the DNA of assemblage A or B and to generate products distinguishable by their melting curves or, after qPCR, by their sequences, sizes, or restriction patterns. The assays showed full specificity and detected DNA from a single trophozoite (4 to 8 target copies). We applied these assays, as well as a TaqMan assay that targets the beta-giardin gene, to genomic DNA extracted from 30 human stools and to Giardia cysts purified by immunomagnetic capture from the same samples. Simultaneous detection of both assemblages was observed in a large number of DNAs extracted from stools, and experiments on the cysts purified from the same samples showed that this was essentially attributable to mixed infections, as only one assemblage was detected when dilutions of cysts were tested. In a few cases, detection of both assemblages was observed even when single cysts were tested. This result, which suggests the presence of recombinants, needs to be confirmed using more accurate methods for cyst separation and enumeration. The assays described in this study can be used to detect Giardia cysts infectious to humans in samples from animals and in water and food.
Collapse
|
29
|
Helmy MMF, Abdel-Fattah HS, Rashed L. Real-time PCR/RFLP assay to detect Giardia intestinalis genotypes in human isolates with diarrhea in Egypt. J Parasitol 2010; 95:1000-4. [PMID: 19254068 DOI: 10.1645/ge-1670.1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 02/16/2009] [Indexed: 11/10/2022] Open
Abstract
Two major genotypic assemblages of Giardia intestinalis infect humans; the nested real-time polymerase chain reaction (PCR) was used for targeting the triose phosphate isomerase (tpi) gene to detect and genotype G. intestinalis in human feces in Egypt. Among 97 fecal samples, 30 (31%) were diagnosed as giardiasis by saline wet mount microscopy after staining with Lugol's iodine. The tpi gene was amplified from 41 (42.3%) fecal samples, of which 11 were microscopy-negative specimens. Of the total samples, 24 (58.5%) contained assemblage A group I, and 7 (17.1%) were assemblage A group II from the group of patients complaining of intermittent diarrhea. Eight (19.5%) samples contained assemblage B from patients with persistent diarrhea. Two (5%) samples had a mixture of assemblage A group II and assemblage B. The technique was able to detect as few as 20 trophozoites per PCR on fecal DNA-isolated, microscopy-negative, and quantitative (q)PCR-positive specimens; there was a higher average cycle threshold value than microscopy-positive and qPCR-positive specimens, suggesting that they represented true, low-burden infections. In conclusion, we could genotype G. intestinalis from fresh stool samples in Egypt; in infections commonly presented with intermittent diarrhea, the most prevalent genotype was assemblage A group I. The most vulnerable age group included 10- to 20-yr-old individuals.
Collapse
Affiliation(s)
- Moshira M F Helmy
- Department of Parasitology, College of Medicine, Misr University for Science and Technology, Al-Motamayez District 6th of October Governorate, Egypt.
| | | | | |
Collapse
|
30
|
Kim J, Shin MH, Song KJ, Park SJ. Evaluation of alpha-tubulin as an antigenic and molecular probe to detect Giardia lamblia. THE KOREAN JOURNAL OF PARASITOLOGY 2009; 47:287-91. [PMID: 19724704 DOI: 10.3347/kjp.2009.47.3.287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 04/20/2009] [Accepted: 05/16/2009] [Indexed: 11/23/2022]
Abstract
The alpha/beta-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant alpha-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of alpha-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the alpha-tubulin gene from G. lamblia. PCR-RFLP analysis of this alpha-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B. The results indicate that alpha-tubulin can be used as a molecular probe to detect G. lamblia.
Collapse
Affiliation(s)
- Juri Kim
- Department of Environmental Medical Biology and Institute of Tropical Medicine, Post Brain Korea 21 Program, Yonsei University College of Medicine, Seoul, Korea
| | | | | | | |
Collapse
|
31
|
Bertrand I, Maux M, Helmi K, Hoffmann L, Schwartzbrod J, Cauchie HM. Quantification of Giardia transcripts during in vitro excystation: interest for the estimation of cyst viability. WATER RESEARCH 2009; 43:2728-2738. [PMID: 19395061 DOI: 10.1016/j.watres.2009.03.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 03/11/2009] [Accepted: 03/14/2009] [Indexed: 05/27/2023]
Abstract
The aim of the present study was to evaluate the potential of transcript quantification as an indicator of Giardia cyst viability. The variations of beta-giardin, EF1A and ADHE mRNAs were quantified during excystation by real-time RT-PCR assays and compared with the percentages of viability estimated using propidium iodide staining and in vitro excystation. The first experiments were performed with purified G. duodenalis assemblage B cysts. When 55% of excysting protozoa were observed, the increase of the selected transcripts ranged from 0.40+/-0.13 to 0.97+/-0.11 log10 after 1h of incubation in excystation medium. Purified cysts were also stored at 4 degrees C for up to 56 days and analysed at several sampling times. Significant correlations were observed between the variations of the selected mRNAs and the percentages of viability estimated with staining and excystation methods. Among the three transcripts, beta-giardin appeared to be the most appropriate to study the viability of Giardia cysts concentrated from wastewater samples.
Collapse
Affiliation(s)
- Isabelle Bertrand
- Centre de Recherche Public-Gabriel Lippmann, Department of Environment and Agro-biotechnologies (EVA), 41 rue du Brill, L-4422 Belvaux, Luxembourg.
| | | | | | | | | | | |
Collapse
|
32
|
Bonjoch X, Lucena F, Blanch AR. The persistence of bifidobacteria populations in a river measured by molecular and culture techniques. J Appl Microbiol 2009; 107:1178-85. [PMID: 19486397 DOI: 10.1111/j.1365-2672.2009.04297.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To determine relative to faecal coliforms (FC) and sulfite-reducing clostridia (SRC), the environmental persistence of natural populations of Bifidobacterium spp. enumerated by culturing and quantitative polymerase chain reaction (q-PCR). METHODS AND RESULTS Dialysis tubing containing river supplemented with overnight cultures of Bifidobacterium adolescentis (BA) and Bifidobacterium dentium (BD) or urban wastewater were suspended in a river for up to 10 days. At intervals, the contents of each dialysis tube were assayed using q-PCR assays for BA and BD, and selective culture media for FC, SRC, total bifidobacteria (TB), sorbitol-fermenting bifidobacteria (SFB) and cultivable BA. Mean summer T(90) values were 251 h for SRC, 92 h for FC, 48 h for BA and BD by q-PCR, and 9 h for TB. CONCLUSIONS Bifidobacterium spp. was the population with the lowest persistence, showing seasonal differences in T(90) when measured by culture techniques or by q-PCR. This difference in relative persistence is because of a longer persistence of molecular targets than cultivable cells. SIGNIFICANCE AND IMPACT OF THE STUDY The persistence of a viable bifidobacteria cells is shorter, but the longest persistence of molecular targets. This factor could be used for origin the faecal pollution in water for the development of microbial source tracking (MST).
Collapse
Affiliation(s)
- X Bonjoch
- Departament de Microbiologia, Universitat de Barcelona, Avinguda Diagonal 645, E-08028 Barcelona, Spain.
| | | | | |
Collapse
|
33
|
Barbosa VL, Atkins SD, Barbosa VP, Burgess JE, Stuetz RM. Characterization of Thiobacillus thioparus isolated from an activated sludge bioreactor used for hydrogen sulfide treatment. J Appl Microbiol 2007; 101:1269-81. [PMID: 17105557 DOI: 10.1111/j.1365-2672.2006.03032.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS To compare Thiobacillus thioparus population dynamics in a control and a test activated sludge (AS) bioreactor, used for hydrogen sulfide (H(2)S) degradation. METHODS AND RESULTS Denaturing gradient gel electrophoresis (DGGE) was used to confirm the presence of T. thioparus, and real-time PCR was used to quantify the level of this bacterium in the AS samples. The DGGE analysis showed a band for T. thioparus in all samples, with the band being more prominent in the test sample with H(2)S diffusion. It also showed that although a change occurred in the diversity of the microbial population in the test sludge after 6 weeks of H(2)S diffusion, the microbial community structure of the test and control was still similar. Thiobacillus thioparus-specific PCR primers confirmed that 50% of the isolates from both the test and control bioreactors were T. thioparus. The thiobacilli population became more efficient at degrading the diffused H(2)S. This increase in efficiency was confirmed by a significant increase in the number of isolates from the test sludge compared with those from the control sludge, when they were grown in a thiosulfate-rich liquid medium. CONCLUSIONS It was concluded that the use of AS process for H(2)S removal encourages the population of T. thioparus to increase even at times when the total biomass concentration shows a decrease. SIGNIFICANCE AND IMPACT OF THE STUDY The research results give an insight into the dynamics of the microbial population in an AS pilot plant used in a dual role, to treat the wastewater and H(2)S.
Collapse
Affiliation(s)
- V L Barbosa
- School of Water Science, Cranfield University, Cranfield, UK
| | | | | | | | | |
Collapse
|
34
|
Fayer R, Santín M, Trout JM, DeStefano S, Koenen K, Kaur T. Prevalence of Microsporidia, Cryptosporidium spp., and Giardia spp. in beavers (Castor canadensis) in Massachusetts. J Zoo Wildl Med 2007; 37:492-7. [PMID: 17315434 DOI: 10.1638/06-013.1] [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] [Indexed: 11/21/2022] Open
Abstract
Feces from 62 beavers (Castor canadensis) in Massachusetts were examined by fluorescence microscopy (IFA) and polymerase chain reaction (PCR) for Microsporidia species, Cryptosporidium spp., and Giardia spp. between January 2002 and December 2004. PCR-positive specimens were further examined by gene sequencing. Protist parasites were detected in 6.4% of the beavers. All were subadults and kits. Microsporidia species were not detected. Giardia spp. was detected by IFA from four beavers; Cryptosporidium spp. was also detected by IFA from two of these beavers. However, gene sequence data for the ssrRNA gene from these two Cryptosporidium spp.-positive beavers were inconclusive in identifying the species. Nucleotide sequences of the TPI, ssrRNA, and beta-giardin genes for Giardia spp. (deposited in GenBank) indicated that the four beavers were excreting Giardia duodenalis Assemblage B, the zoonotic genotype representing a potential source of waterborne Giardia spp. cysts.
Collapse
Affiliation(s)
- Ronald Fayer
- Environmental Microbial Safety Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705, USA
| | | | | | | | | | | |
Collapse
|
35
|
Bertrand I, Albertini L, Schwartzbrod J. Comparison of two target genes for detection and genotyping of Giardia lamblia in human feces by PCR and PCR-restriction fragment length polymorphism. J Clin Microbiol 2006; 43:5940-4. [PMID: 16333079 PMCID: PMC1317193 DOI: 10.1128/jcm.43.12.5940-5944.2005] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A PCR assay targeting the tpi gene was developed to detect and to genotype Giardia lamblia in human feces. Our assay was specific and discriminated between G. lamblia assemblages A and B. G. lamblia cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of tpi or gdh genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assemblage B. Among 26 fecal samples from patients with sporadic giardiasis diagnosed by hospital laboratories, the tpi gene was amplified from 25 (96%) with our PCR assay, whereas only 21 (81%) samples were positive when the gdh gene was targeted. Of the 25 positive samples, nine (36%) contained assemblage A and 16 (64%) contained assemblage B. Thus, RFLP analysis classified eight samples (32%) in assemblage A group II, eight (32%) in assemblage B group III, and five (20%) in assemblage B group IV. The group could not be specified for four samples. The tpi and gdh genes of G. lamblia assemblage B were amplified from 14 (93%) of 15 samples collected only from French soldiers coming back from the Ivory Coast. All of these contained assemblage B group III. The PCR method developed is sensitive, simple, and specific and shows that the tpi gene is well adapted for G. lamblia genotyping.
Collapse
Affiliation(s)
- Isabelle Bertrand
- LCPME-UMR 7564 CNRS-UHP, Equipe Microbiologie et Physique, Faculté de Pharmacie, 5 rue Albert Lebrun, BP 80 403, 54001 Nancy Cedex, France.
| | | | | |
Collapse
|
36
|
Dawson D. Foodborne protozoan parasites. Int J Food Microbiol 2005; 103:207-27. [PMID: 16083823 DOI: 10.1016/j.ijfoodmicro.2004.12.032] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Revised: 11/21/2004] [Accepted: 12/01/2004] [Indexed: 11/18/2022]
Abstract
This report addresses Cryptosporidium, Giardia, Cyclospora, and more briefly, Toxoplasma as the main parasitic protozoa of concern to food production worldwide. Other parasitic protozoa may be spread in food or water but are not considered as great a risk to food manufacture. The protozoan parasites Cryptosporidium, Giardia, and Cyclospora have proven potential to cause waterborne and foodborne disease. Toxoplasma gondii has been considered a risk in specific cases, but humans are not its primary host. Cryptosporidium and Giardia are widespread in the environment, particularly the aquatic environment, and major outbreaks of cryptosporidiosis and giardiasis have occurred as a result of contaminated drinking water. Large outbreaks of waterborne cyclosporiasis have not been identified. Cryptosporidium, Giardia, and Cyclospora have potential significance in the preparation and consumption of fresh produce and in catering practice, in which ready-to-eat foods may be served that have not received heat treatment. None of the three organisms Cryptosporidium, Giardia, and Cyclospora has been shown to be a problem for heat processed food or tap water that has undergone appropriate treatment at a water treatment works. All three are sensitive to standard pasteurisation techniques. Although humans are not a primary host for T. gondii, the potential exists for both waterborne and foodborne toxoplasmosis. Parasitic protozoa do not multiply in foods, but they may survive in or on moist foods for months in cool, damp environments. Their ecology makes control of these parasites difficult. For general control of parasitic protozoa in the food chain, the following steps are necessary: - Follow good hygienic practice in food service and catering industries.- Minimise dissemination of cysts and oocysts in the farming environment and via human waste management.- Include these microorganisms in Hazard Analysis Critical Control Point (HACCP) plans of water suppliers, industries or sectors that use fresh produce, and operations in which contaminated process or ingredient water could end up in the product (e.g., where water supplies may become contaminated).
Collapse
Affiliation(s)
- David Dawson
- Campden and Chorleywood Food Research Association, Microbiology Department, Chipping Campden, Gloucestershire GL55 6LD, United Kingdom.
| |
Collapse
|
37
|
Monis PT, Giglio S. Nucleic acid amplification-based techniques for pathogen detection and identification. INFECTION GENETICS AND EVOLUTION 2005; 6:2-12. [PMID: 16169776 PMCID: PMC7106022 DOI: 10.1016/j.meegid.2005.08.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 07/29/2005] [Accepted: 08/01/2005] [Indexed: 11/28/2022]
Abstract
Nucleic acid amplification techniques have revolutionised diagnostic and research industries. Current technologies that allow the detection of amplification in real-time are fast becoming industry standards, particularly in a diagnostic context. In this review, we describe and explore the application of numerous real-time detection chemistries and amplification techniques for pathogen detection and identification, including the polymerase chain reaction, nucleic acid sequence-based amplification, strand displacement amplification and the ligase chain reaction. The emergence of newer technologies, such as lab-on-a-chip devices and photo-cleavable linkers, is also discussed.
Collapse
Affiliation(s)
- Paul T Monis
- Australian Water Quality Centre, South Australian Water Corporation, Microbiology Unit, Salisbury, SA 5108, Australia.
| | | |
Collapse
|
38
|
Monis PT, Giglio S, Keegan AR, Andrew Thompson RC. Emerging technologies for the detection and genetic characterization of protozoan parasites. Trends Parasitol 2005; 21:340-6. [PMID: 15925542 DOI: 10.1016/j.pt.2005.05.012] [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] [Received: 01/17/2005] [Revised: 04/04/2005] [Accepted: 05/10/2005] [Indexed: 11/21/2022]
Abstract
The development and adaptation of new technologies for the genetic characterization and identification of parasites continue to accelerate, providing an increasing number of research and analytical tools. We review emerging technologies that have applications in this area, including real-time PCR and microarrays, and discuss the fundamental principles of some of these technologies and how they are applied to characterize parasites. We give special consideration to the application of genetic data to biological questions, where selection of the most appropriate technique depends on the biological question posed by the investigator.
Collapse
Affiliation(s)
- Paul T Monis
- Australian Water Quality Centre, South Australian Water Corporation, Private Mail Bag 3, Salisbury, South Australia 5108, Australia.
| | | | | | | |
Collapse
|
39
|
Ng CT, Gilchrist CA, Lane A, Roy S, Haque R, Houpt ER. Multiplex real-time PCR assay using Scorpion probes and DNA capture for genotype-specific detection of Giardia lamblia on fecal samples. J Clin Microbiol 2005; 43:1256-60. [PMID: 15750093 PMCID: PMC1081263 DOI: 10.1128/jcm.43.3.1256-1260.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Revised: 10/14/2004] [Accepted: 11/09/2004] [Indexed: 01/24/2023] Open
Abstract
Two major genotypic assemblages of Giardia lamblia infect humans; the epidemiologic significance of this phenomenon is poorly understood. We developed a single-vessel multiplex real-time PCR (qPCR) assay that genotypes Giardia infections into assemblages A and/or B directly from fecal samples. The assay utilized Scorpion probes that combined genotype-specific primers and probes for the 18S rRNA gene into the same molecule. The protocol was capable of detecting as few as 20 trophozoites per PCR on fecal DNA isolated using a commercial method or 1.25 trophozoites per PCR on fecal DNA isolated using a G. lamblia-specific oligonucleotide capture technique. The assay was specific for fecal specimens, with no amplification of the discordant genotype with the opposite Scorpion probe. When 97 clinical specimens from Bangladesh were used, the multiplex PCR assay detected 95% (21 of 22) of Giardia microscopy-positive specimens and 18% (13 of 74) of microscopy-negative specimens. Microscopy-negative and qPCR-positive specimens had higher average cycle threshold values than microscopy-positive and qPCR-positive specimens, suggesting that they represented true low-burden infections. Most (32 of 35) infections were assemblage B infections. This single-reaction multiplex qPCR assay distinguishes assemblage A Giardia infections from assemblage B infections directly on fecal samples and may aid epidemiologic investigation.
Collapse
Affiliation(s)
- Cherie T Ng
- Division of Infectious Diseases and International Health, University of Virginia, MR4 Building, Room 2144, P.O. Box 801340, Charlottesville, VA 22908, USA
| | | | | | | | | | | |
Collapse
|