Cyst detection and viability assessment of Balantioides coli in environmental samples: Current status and future needs

A Thorny Tale of Parasites: Screening for Enteric Protozoan Parasites in Hedgehogs from Portugal

Enteric protozoan parasites, such as Blastocystis sp., Balantioides coli, Cryptosporidium spp., and Giardia duodenalis, may have implications for both animal and human health.Transmitted through the fecal-oral route, these parasites cause symptoms such as diarrhea, abdominal pain, and weight loss. This study investigated the presence of these enteric protozoan parasites and genetically characterized them in hedgehogs from Portugal. A total of 110 hedgehog stool samples were collected. Molecular detection methods showed an overall occurrence of protozoa in 1.82% (2/110 95% CI: 0.22-6.41) of hedgehogs, with Blastocystis being found in one hedgehog and Cryptosporidium being found in another. No evidence for the presence of B. coli or G. duodenalis was found. This study suggests that there is a need to stay aware of hedgehogs as potential hosts of enteric protozoa. Ongoing research and surveillance efforts are recommended to explore practical prevention and control strategies. The results contribute to the limited knowledge of these parasites in Portuguese hedgehog populations and underscore their potential relevance to both veterinary and public health.

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.

Comparative Genomic and Transcriptomic Profiling Revealed the Molecular Basis of Starch Promoting the Growth and Proliferation of Balantioides coli

Carbohydrates are the main source of nutrition for B. coli, supplying energy for cell growth and development. The research aimed at investigating the mechanism of starch on the growth and replication of B. coli. Single-cell separation was used to isolate single trophozoites of B. coli under a stereomicroscope, transcriptomic profiling was conducted based on the SMART-seq2 single-cell RNA-seq method. Comparative genomic analysis was performed on B. coli and eight other ciliates to obtain specific and expanded gene families of B. coli. GO and KEGG enrichment analysis were used to analyze the key genes of B. coli under the action of starch in the present study. The results of single-cell RNA-seq depicts starch affected the growth and replication of B. coli in two ways: (1) the cell cycle was positively promoted by the activation of the cAMP/PKA signaling pathway via glycolysis; (2) the cell autophagy was suppressed through the PI3K/AKT/mTOR pathway. Genes involved in endocytosis, carbohydrate utilization, and the cAMP/PKA signaling pathway were highly enriched in both specific and expanded gene families of B. coli. Starch can be ingested and hydrolyzed into glucose, in turn affecting various biological processes of B. coli. The molecular mechanism of the effect of starch on the growth and proliferation of B. coli by promoting cell cycle and inhibiting the autophagy of trophozoites has been elucidated in our study.

Balantioides coli Fecal Excretion in Hunted Wild Cervids (Cervus elaphus and Dama dama) from Portugal

Balantioides coli is a zoonotic enteric protozoan parasite of public veterinary health relevance and a concern in animal production and food safety. While wild cervids are recognized reservoirs for several zoonotic pathogens, little is known about the occurrence of B. coli in deer species, especially in Europe. To fill this gap, a total of 130 fecal samples from legally hunted red deer (Cervus elaphus, n = 95) and fallow deer (Dama dama, n = 35) were passively collected during two hunting seasons (October to February; 2018-2019 and 2019-2020) in Portugal. After assessment by PCR assay targeting the complete ITS1-5.8s-rRNA-ITS2 region and the 3' end of the ssu-rRNA gene of the parasite, a prevalence of 4.2% (4/95, 95% CI: 0.2-8.3) in red deer and of 5.7% (2/35, 95% CI: 0.0-13.4) in fallow deer was found. Sequence and phylogenetic analyses allowed the identification of B. coli genetic variants A (in two red deer) and B (in two red deer and two fallow deer). This is the first molecular-based description of B. coli in European deer species, whose population have increased in density and geographical range in recent years. Continued monitoring of wild ungulates as potential vectors of parasitic infection diseases of zoonotic nature is crucial to safeguard public health and food safety.