scholarly journals Detection methods and prevalence of transmission stages of Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp. in fresh vegetables: a review

Parasitology ◽  
2020 ◽  
Vol 147 (5) ◽  
pp. 516-532 ◽  
Author(s):  
Salma Berrouch ◽  
Sandie Escotte-Binet ◽  
Rajae Harrak ◽  
Antoine Huguenin ◽  
Pierre Flori ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Health Hazard ◽  
Parasitic Infection ◽  
Geographical Location ◽  
Giardia Duodenalis ◽  
Detection Methods ◽  
Detection And Identification ◽  
Fresh Vegetables ◽  
Parasite Detection ◽  
Human Health Hazard

AbstractOne of the ways of human parasitic infection is the accidental ingestion of vegetables contaminated with parasites, which represents a major human health hazard. This non-exhaustive review aims to evaluate studies carried out on five types of vegetables (lettuce, parsley, coriander, carrot and radish) since 2000, particularly the methods used for recovery, concentration, detection and identification of protozoan parasites such as Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp., and the results of each work. Various studies have determined the presence of pathogenic parasites in fresh vegetables with different rates; this variation in rate depends particularly on the detection method used which is related to each parasite and each vegetable type. The variation in parasitic prevalence in food could be due to different factors such as the geographical location, the size of analysed samples and the methods used for parasite detection.

scholarly journals Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii detection in fresh vegetables consumed in Marrakech, Morocco

2020 ◽  
Vol 20 (4) ◽  
pp. 1669-78
Author(s):  
Salma Berrouch ◽  
Sandie Escotte-Binet ◽  
Yassine Amraouza ◽  
Pierre Flori ◽  
Dominique Aubert ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Giardia Duodenalis ◽  
Epidemiological Data ◽  
Contaminated Water ◽  
Protozoan Parasites ◽  
Leafy Greens ◽  
Cryptosporidium Spp ◽  
Vegetable Samples ◽  
Fresh Vegetables

Background: Protozoan parasites such as Toxoplasma gondii, Giardia duodenalis, and Cryptosporidium spp., can be transmitted to humans via accidental consumption of contaminated water, fresh produce and foodstuffs. There is a lack of epidemiological data about these pathogens in Morocco. Hence the aim of this study, which is the determination of their prevalence in some leafy greens and root vegetables sold in Marrakech. Methods: A total of 132 vegetable samples including carrot, coriander, lettuce, parsley and radish were purchased monthly from three different markets in Marrakech from March 2017 to January 2018, pre-treated and subjected to microscopic and molecular analyses. Results: Of the 132 samples of vegetables analyzed by qPCR, the overall rate of protozoan was 21.21% (28/132); 22 samples were found to be contaminated with T. gondii, 6 with G. duodenalis, and none was positive for C. parvum/hominis. Whereas, modified Ziehl-Neelsen staining allowed the detection of Cryptosporidium spp. in 3% (4/132) of examined samples. Conclusion: This survey on the presence of protozoan parasites in fresh vegetables revealed that vegetables sold in Marrakech are contaminated by these protozoan parasites, as it showed that leafy green vegetables were more susceptible for parasitic contamination than root ones. Keywords: Fresh vegetables; protozoan parasites; Marrakech; qPCR.

Viruses and Water: Problems, Detection, and Control

1993 ◽  
Vol 27 (7-8) ◽  
pp. 127-133 ◽  
Author(s):  
H. Dizer ◽  
J. Dürkop ◽  
A. Grohmann ◽  
H. Kopecka ◽  
J. M. López-Pila
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Membrane Filtration ◽  
Wastewater Treatment Plants ◽  
Health Hazard ◽  
Primary Source ◽  
Detection Methods ◽  
Secondary Effluent ◽  
Naturally Occurring ◽  
Water Problems

Secondary effluent of wastewater treatment plants contains a high number of viruses and other pathogens, which pose a health risk to the population, (especially when receiv ng waters are used for bathing and swimming, or for growing shellfish. In areas with a high density of population, where drinking water supply is dependent on surface waters and contaminated rivers are the primary source of drinking water, failure of the filtration or of the disinfection step, or of any other “barriers” supposed to warrant safe potable water, will increase the risk of health hazard for the consumer. We have compared the efficiency of viral elimination in secondary effluent by flocculation, uv rradiation and membrane filtration taking naturally occurring, or additionally seeded f2 phages, as indicator for viruses. Flocculation decreased the number of phages present in secondary effluent by more than two logs. If combined with uv irradiation, the elimination reached five additional logs. Membrane filtration eliminated essentially all naturally occurring phages. Improvement of the quality of surface waters calls for a refinement of detection methods for viruses. We have found that the polymerase chain reaction (PCR) might be used for detecting viruses in surface waters.

scholarly journals Development of Novel Multiplex PCR for Diagnosis of Co-infected Hemo-parasites in Cattle

2021 ◽  
Author(s):  
Pankaj Kumar ◽  
Abhay Kumar ◽  
Kamal Sarma ◽  
Paresh Sharma ◽  
Rashmi Rekha Kumari ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Large Scale ◽  
Parasitic Infection ◽  
Epidemiological Studies ◽  
Kappa Coefficient ◽  
Detection Methods ◽  
Diagnostic Process ◽  
Specific Gene ◽  
Rrna Gene ◽  
Babesia Bigemina

Background: A novel, rapid and specific multiplex polymerase chain reaction was developed to diagnose hemo-parasitic infection in bovine blood co-infected with three of the most common hemo-parasites. Methods: The diagnostic process relied on the detection of the three different bovine hemoparasites isolated from red blood cells (RBCs) of cattle (N=30) by conventional Giemsa stained blood smear (GSBS) and confirmed by multiplex PCR. The multiplex PCR system was used to diagnose GSBS positive blood samples (N=12) found infected or co-infected with hemoparasites. The designed multiplex primer sets was attempted to amplify 205, 313 and 422 bp fragments of apocytochrome b, sporozoite and macroschizont 2 (spm2) and 16S rRNA gene for Babesia bigemina, Theileria annulata and Anaplasma marginale, respectively. Result: This multiplex PCR was sensitive with the ability to detect the presence of 150 ng of genomic DNA. The primers used in this multiplex PCR also showed highly specific amplification of specific gene fragments of each respective parasite. Comparing the two detection methods revealed that 58.33% of specimens showed concordant diagnoses with both techniques. The specificity, positive predictive value and kappa coefficient of the agreement was highest for diagnosis of B. bigemina and lowest for A. marginale. The overall Kappa coefficient for diagnosis based on GSBS for multiple pathogens compared to multiplex PCR was 0.56, slightly behind the threshold of 0.6 of agreement. Therefore, confirmation should always be based on PCR to rule out false positives due to differences in subjective observations, stain particles and false negatives due to low parasitemia. The simplicity and rapidity of this specific multiplex PCR method make it suitable for large-scale epidemiological studies and follow-up of drug treatments.

scholarly journals Molecular beacons allow specific RT-LAMP detection of B.1.1.7 variant SARS-CoV-2

2021 ◽  
Author(s):  
Scott Sherrill-Mix ◽  
Gregory D. Van Duyne ◽  
Frederic D. Bushman
Keyword(s):  
Genetic Variants ◽  
Molecular Beacons ◽  
Spike Protein ◽  
Detection Methods ◽  
Gene Encoding ◽  
Detection And Identification ◽  
Rapid Spread ◽  
The World ◽  
Primer Sets ◽  
Current Detection

AbstractOver the course of the COVID-19 pandemic, several SARS-CoV-2 genetic variants of concern have appeared and spread throughout the world. Detection and identification of these variants is important to understanding and controlling their rapid spread. Current detection methods for a particularly concerning variant, B.1.1.7, require expensive qPCR machines and depend on the absence of a signal rather than a positive indicator of variant presence. Here we report an assay using a pair of molecular beacons paired with reverse transcription loop mediated amplification to allow isothermal amplification from saliva to specifically detect B.1.1.7 and other variants which contain a characteristic deletion in the gene encoding the viral spike protein. This assay is specific, affordable and allows multiplexing with other SARS-CoV-2 LAMP primer sets.

scholarly journals Performance of 2 Polymerization Protocols Targeting Cloned Toxoplasma Parasites

2018 ◽  
Vol 6 (9) ◽  
pp. 1577-1580
Author(s):  
Nihal A. Hanafy ◽  
Mohamed S. Badr ◽  
Ghada M. Nasr
Keyword(s):  
Toxoplasma Gondii ◽  
Real Time ◽  
Parasitic Infection ◽  
Clinical Samples ◽  
Molecular Assays ◽  
Low Concentrations ◽  
Target Dna ◽  
Primer Sets ◽  
Amplification Failure ◽  
Reference Samples

BACKGROUND: Toxoplasma gondii is a common parasitic infection of humans. Infection is usually mild. Serious complications can occur in pregnant and immunocompromised patients. AIM: The present study aims to investigate the performance of 2 different PCR protocols; real-time quantitative molecular assays (qPCR) and conventional molecular assays (cPCR), using 2 different sets of primers and by using cloned purified Toxoplasma genomic substances to be evaluated as reference samples. METHODS: The target DNA was provided in 8 different quantities. RESULTS: Amplification failure was reported only with the cPCR in samples of low concentrations using both primer sets. Quantitative PCR detected the 8 different dilutions of the purified Toxoplasma gondii using the 2 sets of primers while cPCR was sensitive to detect only 6 different dilutions. CONCLUSION: Generally real-time quantitative molecular assays, is easy to use method compared to conventional PCR assay and produces more reliable results within only one hour time but still the possible application of qPCRs in routine diagnosis necessitates analysis of a large number of clinical samples in further studies to make the proper choice.

scholarly journals Survey study of intestinal parasites on Fresh vegetables collected from some Baghdad Sales and its role in human infection

2013 ◽  
Vol 10 (1) ◽  
pp. 32-40
Author(s):  
Baghdad Science Journal
Keyword(s):  
Intestinal Parasites ◽  
Parasitic Infection ◽  
Human Infection ◽  
Healthy Diet ◽  
Survey Study ◽  
Total Percentage ◽  
Fresh Vegetables ◽  
East West

Fresh vegetables are an important part of a healthy diet. The consumption of raw vegetables without cooking or good washing can be a major rout of transmission to the parasitic infection. The goal of this study was to determine the intestinal parasitic contamination of fresh vegetables from vegetables sales markets in Baghdad province during the different above months of the year. A total of 303 samples of different vegetables were randomly selected from three wholesale markets distributed through different regions in Baghdad (East, West and South) and then were examined by a floatation method. The present study showed that the collected vegetables were contaminated with 12 species of intestinal parasites, and the total percentage of contamination was 161 (53.1%) . ZnSo4 solution showed the highest percentage of contaminated vegetables (31.2%) while sucrose showed the lowest percentage (8.9%).

scholarly journals The impacts of precursor reduction and meteorology on ground-level ozone in the Greater Toronto Area

2014 ◽  
Vol 14 (15) ◽  
pp. 8197-8207 ◽  
Author(s):  
S. C. Pugliese ◽  
J. G. Murphy ◽  
J. A. Geddes ◽  
J. M. Wang
Keyword(s):  
Health Hazard ◽  
Ground Level ◽  
Ozone Production ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
Greater Toronto Area ◽  
High Solar Radiation ◽  
Linear Effects ◽  
Human Health Hazard ◽  
Ozone Levels

Abstract. Tropospheric ozone (O3) is a major component of photochemical smog and is a known human health hazard, as well as a damaging factor for vegetation. Its precursor compounds, nitrogen oxides (NOx) and volatile organic compounds (VOCs), have a variety of anthropogenic and biogenic sources and exhibit non-linear effects on ozone production. As an update to previous studies on ground-level ozone in the Greater Toronto Area (GTA), we present an analysis of NO2, VOC and O3 data from federal and provincial governmental monitoring sites in the GTA from 2000 to 2012. We show that, over the study period, summertime 24 h VOC reactivity and NO2 midday (11:00–15:00) concentrations at all sites decreased significantly; since 2000, all sites experienced a decrease in NO2 of 28–62% and in measured VOC reactivity of at least 53–71%. Comparing 2002–2003 to 2011–2012, the summed reactivity of OH towards NO2 and a suite of measured VOCs decreased from 8.6 to 4.6 s−1. Ratios of reactive VOC pairs indicate that the effective OH concentration experienced by primary pollutants in the GTA has increased significantly over the study period. Despite the continuous decrease in precursor levels, ozone concentrations are not following the same pattern at all stations; it was found that the Canada-wide Standard for ozone continues to be exceeded at all monitoring stations. Additionally, while the years 2008–2011 had consistently lower ozone levels than previous years, 2012 experienced one of the highest recorded summertime ozone concentrations and a large number of smog episodes. We demonstrate that these high ozone observations in 2012 may be a result of the number of days with high solar radiation, the number of stagnant periods and the transport of high ozone levels from upwind regions.

Sign in / Sign up

Export Citation Format

Share Document