Protozoan Parasites and Leafy Greens in Marrakech: Study of Occurrence Using a Molecular Method

First report of molecular detection and phylogenetic analysis of Toxoplasma Gondii in soil, water and vegetables from Chandigarh city, India

Toxoplasma gondii, a zoonotic protozoan parasite, affects up to one-third of the global population. It can be transmitted through consumption of raw or undercooked meat, vertical transmission, or oocysts from contaminated water, soil, or food. However, there are no reports on the molecular prevalence of T. gondii in environmental sources like soil, water, and vegetables in India. This study aimed to detect and analyze T. gondii in samples from Chandigarh city, India. A total of 100 each soil & water and 500 vegetable samples were collected and analyzed using conventional PCR assay, real-time PCR assay targeting the glycerol-3-phosphate dehydrogenase (B1) gene and real-time LAMP assay targeting both B1 and Toxoplasma gondii outer wall protein (TgOWP) genes. Results showed that 15% of water, 9% of soil, and 6.4% of vegetable samples were positive for T. gondii. Real-time PCR assay and real-time LAMP assay detected slightly higher positivity rates in water and vegetable samples. Phylogenetic analysis revealed that the T. gondii isolates clustered with those from other regions such as Iran, India, Mexico, and those found in cats, pigs, and humans. This study is the first report of T. gondii contamination in environmental sources and fresh produce in India. The findings highlight the potential risk of human infection from contaminated water, soil, and vegetables in the region.

Unveiling risks in healthy food: Vegetables and fruits are linked to the distribution chain of protozoan parasites

Vegetable and fruit contamination is recognized as a significant parasite transmission route. This review presents the current state of vegetables ad fruits contamination with food-borne parasitic protozoa worldwide. We consider the methodologies and strategies for detecting parasitic stages developed in the last decade and the contamination data. Asia had the highest number of reports (94 studies), followed by Africa (74 studies). At the country level, with 41 studies, Iran had the most reports among other countries, followed by Nigeria (28 studies). According to the studies included in the current review, 41.22% of vegetables and fruits were contaminated with different species of protozoan parasites. Among different continents, Asia accounted for the highest contamination rate of protozoan parasites (57.12%). Giardia spp. (10%) had the highest contamination rate in vegetables and fruits, followed by Entamoeba coli (8%), E. histolytica/dispar (7%), and Cryptosporidium spp. (6%). This study provides essential data for health authorities to develop food safety programs. The presence of protozoan parasites in fruits and vegetables highlights the critical need for maintaining rigorous food safety measures across the entire production and distribution process, particularly in countries that are major producers and distributors of these food items.

Toxoplasma Gondii in humans, animals and in the environment in Morocco: a literature review

Toxoplasmosis, caused by Toxoplasma gondii, has the unsettling ability to infect nearly every warm-blooded vertebrate. When transmitted from mother to fetus during pregnancy, it can lead to congenital toxoplasmosis in newborns, which may have severe and even fatal outcomes. Moreover, this parasite is a significant cause of reproductive issues in cattle. The aim of this literature review was to compile and synthesize information on the epidemiology and clinical features of naturally occurring Toxoplasma gondii infections in both humans and animals, as well as to assess the occurrence of oocysts in the environmental matrices in Morocco. To achieve these objectives, data were sourced from four electronic databases: PubMed, Web of Science, Scopus, and Google Scholar. A total of 32 articles published between January 1, 2000, and January 31, 2024, met the inclusion criteria. The findings indicated that the seroprevalence of T. gondii among pregnant women varied by city and appeared to be lower in drier climates. The study identified several risk factors associated with T. gondii infection among women in Morocco, including direct contact with soil, failure to wash fruits and vegetables before eating, limited education, and reliance on well water for drinking. Moreover, there is a limited amount of serological data on T. gondii in animals. In Morocco, the prevalence of this parasite can reach up to 30% in sheep, while it stands at 8.5% in cattle and goats. Leafy greens are particularly prone to hosting pathogens and are associated with foodborne outbreaks. In Morocco, the prevalence of T. gondii in leafy vegetables is around 16%, although soil analyses have not found any oocysts. This review offers a thorough epidemiological overview of T. gondii infections in Morocco, serving as a valuable resource for researchers and aiding in the development of control and prevention programs.

Protozoan parasites and free-living amoebae contamination in organic leafy green vegetables and strawberries from Spain

In this study, the presence of Acanthamoeba spp., Blastocystis sp., Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, Giardia sp., Toxoplasma gondii and Vermamoeba vermiformis was assessed in organic leafy green vegetables (lettuce, spinach, cabbage) and fruits (strawberry), which are usually consumed raw. A total of 110 organic samples were collected in Valencia (Spain). Protozoa were concentrated before detection by immunofluorescence (Cryptosporidium spp. and Giardia sp.) or real-time qPCR (Acanthamoeba spp., Blastocystis sp., C. cayetanensis, E. histolytica, T. gondii and V. vermiformis). The most abundant protozoa in organic vegetables and berry fruits were Acanthamoeba (65.5%), followed by T. gondii (37.2%), V. vermiformis (17.3%), C. cayetanensis (12.7%), Cryptosporidium spp. (6.8%), Blastocystis sp. (1.8%) and Giardia sp. (1.7%). E. histolytica was not found in any of the organic samples. Thus, results showed that consumers can be exposed to protozoan parasites by consuming organic vegetables and berry fruits. This is the first report in Spain describing the presence of the protozoan pathogens Acanthamoeba spp., Blastocystis sp., C. cayetanensis, T. gondii and V. vermiformis, Cryptosporidium spp. and Giardia sp. in organic fresh produce. The results of this research will help determine the risk of foodborne protozoan parasites on organic leafy greens and strawberries that are available at local markets.

Investigating the Occurrence of Soil-Transmitted Parasites Contaminating Soil, Vegetables, and Green Fodder in the East of Nile Delta, Egypt

Background

Food-borne parasites are major sources of human and animal illness, posing severe health risks in places with contaminated soil, poor water quality, cleanliness, and poor sanitation. The usage of untreated organic fertilizers arising from the excreta of the parasites' definitive hosts either man or animal pollutes the agricultural soil and is reflected in its products of vegetables and green fodders causing serious health problems. Therefore, to the best of our knowledge, this will be the first study that investigated the combination of parasitic contamination of the agricultural soil and its products of raw eaten vegetables and green fodder in East Nile Delta, Egypt.

Aim

The purpose of this study was to investigate the type and degree of contamination caused by parasites in regularly used raw vegetables, green fodder, and soil samples collected from open fields in Egypt's East Nile Delta. Study Procedures. A cross-sectional study comprised a simple random collection of 400 soil samples, 180 green fodder samples, and as well as 400 vegetable samples, including lettuce, radish, coriander, parsley, dill, watercress, tomatoes, green pepper, cucumber, and carrot, that were gathered throughout one year period from January to December 2021 to represent all seasons (winter, spring, summer, and autumn). The research locations were chosen from various open green fields and farming regions in Egypt's East Nile Delta producing ready-to-eat vegetables for human consumptions and planting green fodder for animal feeding. Concentrations, including sedimentation, and flotation, and staining techniques were used to recover the greatest number of parasitic life forms. The parasitic structures discovered were identified using biometric and imaging data and compared with known parasite morphology. Statistical analysis was performed with the SPSS software version 22 (IBM, Chicago, IL, USA). Data were presented in numbers and percentages. P-values equal to or less than 0.05 were considered to be statistically significant. The difference in parasitic contamination among the different categories was compared using the chi-square test.

Results

In this investigation, 243 out of 400 soil samples (60.7%) confirmed positive for parasitic contamination (P < 0.05). Various parasitic life forms were significantly found in 249 out of 400 (62.25%) of the vegetable samples, with (65.1%) of them harboring one parasite species, whereas 9.2% significantly contained up to three parasites. Ascaris eggs, Trichuris eggs, and Giardia cysts were the most prevalent parasites, which were predominantly isolated from vegetables with uneven surfaces. 109 of 180 (60.0%) green fodder samples confirmed insignificantly positive for parasitic pollution. The proportion of parasite contamination in vegetable samples was insignificant although the highest was in spring (29.3%), followed by summer (27.7%), whereas it is significant in autumn (24.5%). The prevalence rate was the lowest in winter (20.1%). Conclusion and Recommendations. Our findings demonstrated a significant load of parasites notably the soil-transmitted parasitic infection in raw vegetables and green fodder cultivated in open fields as well as in their mother soil in the east of the Nile Delta, Egypt. These results confirm the urgent need to deploy strict control measures to the soil, especially during the pre-harvest period of raw eaten vegetables and green fodder, a critical step in reducing food-borne transmission of soil-transmitted parasites to man and animals.

Investigation of the presence of Toxoplasma gondii, Giardia duodenalis and Cryptosporidium spp. in drinking waters in the region of Marrakech, Morocco

The association between the parasitic illnesses and the consumption of contaminated water has been largely reported. However, there is still a lack of studies investigating the extent of parasitic contamination in water in Morocco. This is the first study in Morocco that aimed at assessing the presence of protozoan parasites, namely Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii, in drinking water consumed in the region of Marrakech. Samples processing was performed by membrane filtration and qPCR detection. A total of 104 drinking water samples (tap water, well and spring waters) was collected between 2016 and 2020. The analysis revealed an overall protozoa contamination rate of 67.3% (70/104), of which 35 samples were positive for Giardia duodenalis, 18 for Toxoplasma gondii and 17 for both parasites. Whereas no sample was positive for Cryptosporidium spp. This first study showed that drinking water in the region of Marrakech contained parasites which could represent a risk for consumers. For better understanding and estimation of the risk encountered by local inhabitants, further studies concerned with (oo)cyst viability, infectivity and genotype identification need to be performed.

Persistence and survival of Cryptosporidium parvum oocysts on lamb's lettuce leaves during plant growth and in washing conditions of minimally-processed salads

Cryptosporidium is the causative agent of cryptosporidiosis, which results, among others, in profuse diarrhoea. Transmission to humans occurs via the faecal-oral route directly by contact with infected hosts or indirectly by waterborne or foodborne routes. For the latter, parasite transmission is closely linked to the oocyst's ability to persist and survive in food matrices. In this study, we evaluated the persistence and survival of Cryptosporidium oocysts in lamb's lettuce: i) during plant growth and ii) in conditions mimicking the industrial washing process applied in minimally-processed vegetables (MPV). Results show that oocysts persisted during the growth of lamb's lettuce, i.e. two months from the 2-leaf stage until the 8-leaf harvest time (-0.89 Log10 of oocysts). However, their survival decreased from as early as one week (-0.61 Log10), and only 6 % of oocysts remained infective at the time of harvest. The washing process had a limited effect on parasite load (<0.5 Log10) and no effect on survival; chlorination of washing water did not improve the efficiency (removal and inactivation) of the process. The ability of C. parvum to persist and survive throughout the food chain may drive its transmission to humans through MPV products. Appropriate management measures should be implemented at each operational level to limit contamination and ensure food safety of fresh produce.

Toxoplasma gondii in Foods: Prevalence, Control, and Safety

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, with approximately one third of the population around the world seropositive. The consumption of contaminated food is the main source of infection. These include meat products with T. gondii tissue cysts, and dairy products with tachyzoites. Recently, contamination has been detected in fresh products with oocysts and marine products. Despite the great health problems that are caused by T. gondii, currently there are no standardized methods for its detection in the food industry. In this review, we analyze the current detection methods, the prevalence of T. gondii in different food products, and the control measures. The main detection methods are bioassays, cell culture, molecular and microscopic techniques, and serological methods, but some of these do not have applicability in the food industry. As a result, emerging techniques are being developed that are aimed at the detection of multiple parasites simultaneously that would make their application more efficient in the industry. Since the prevalence of this parasite is high in many products (meat and milk, marine products, and vegetables), it is necessary to standardize detection methods, as well as implement control measures.