Prevalence and genotype analysis of Cryptosporidium and Giardia duodenalis from shelter dogs in South Korea.

Cryptosporidium and Giardia duodenalis are common gastrointestinal protozoan parasites that cause diarrhea in humans and animals. Although dogs in animal shelters in South Korea can be reintroduced into human society as companions, no continuous investigations have been conducted on the prevalence and genetic characteristics of the protozoan parasites. In the present study, 345 fecal samples from dogs were obtained from animal shelters in six provinces between January and December 2022. The prevalence of Cryptosporidium and G. duodenalis were molecularly identified at the 18S rRNA gene. Cryptosporidium canis isolates were subtyped at the gp60 locus, and G. duodenalis assemblages were identified at the tpi, bg and gdh loci. Overall, 6.67% of the fecal samples tested positive for Cryptosporidium spp. and two species were identified: C. canis (5.51%) and Cryptosporidium parvum (1.16%). Significant regional differences in prevalence were identified for C. canis. Subtyping analysis of C. canis isolates revealed a predominance of the subtype families XXa and XXe over XXb, and XXc. G. duodenalis was detected in 17.68% of the samples, and significant regional differences were identified; its prevalence was also significantly highest in diarrhoeic animals. Molecular characterization of G. duodenalis reveal that most isolates belonged to the canine-specific assemblages C and D. The present results can contribute to further insights into the prevalence and genotypes of Cryptosporidium and G. duodenalis in shelter dogs in South Korea.

Tunneling Nanotube-like Structures in Giardia duodenalis.

Giardia doudenalis (lamblia, intestinalis) is a protozoan parasite that inhabits the lumen of the upper small intestine of vertebrates, causing chronic abdominal pains and severe diarrhea, symptoms of giardiasis, a persistent and recurrent infection. This characteristic is mainly due to the presence of membrane variant-specific surface proteins (VSPs) that give this parasite the ability to successively infect the host through antigenic variation. Using high-resolution scanning microscopy (HR-SM), we observed the presence, formation, and extension of tunneling-nanotube-like surface structures in Giardia, especially following parasite challenges with VSP antibodies. They were seen all over the parasite surface, both in vitro and in vivo, showing that G. duodenalis nanotube formation occurs in complex environments such as the gut. In addition, we also observed that some of these nanotubes displayed a periodic strangulation that produces 100 nm vesicles that seemed to be released in a process similar to that previously observed in Trypanosoma brucei. The presence of nanotube-like structures in G. duodenalis highlights yet another strategy of cellular communication utilized by these parasites, whether between themselves or with the host cell.

Comprehensive analysis of flavohemoprotein copy number variation in Giardia intestinalis: exploring links to metronidazole resistance.

BACKGROUND: Giardiasis, caused by the protozoan parasite Giardia intestinalis, often presents a treatment challenge, particularly in terms of resistance to metronidazole. Despite extensive research, markers for metronidazole resistance have not yet been identified. METHODS: This study analysed 28 clinical samples of G. intestinalis from sub-assemblage AII, characterised by varying responses to metronidazole treatment. We focussed on copy number variation (CNV) of the multi-copy flavohemoprotein gene, analysed using digital polymerase chain reaction (dPCR) and next generation sequencing (NGS). Additionally, chromosomal ploidy was tested in 18 of these samples. Flavohemoprotein CNV was also assessed in 17 samples from other sub-assemblages. RESULTS: Analyses revealed variable CNVs of the flavohemoprotein gene among the isolates, with no correlation to clinical metronidazole resistance. Discrepancies in CNVs detected from NGS data were attributed to biases linked to the whole genome amplification. However, dPCR helped to clarify these discrepancies by providing more consistent CNV data. Significant differences in flavohemoprotein CNVs were observed across different G. intestinalis sub-assemblages. Notably, Giardia exhibits a propensity for aneuploidy, contributing to genomic variability within and between sub-assemblages. CONCLUSIONS: The complexity of the clinical metronidazole resistance in Giardia is influenced by multiple genetic factors, including CNVs and aneuploidy. No significant differences in the CNV of the flavohemoprotein gene between isolates from metronidazole-resistant and metronidazole-sensitive cases of giardiasis were found, underscoring the need for further research to identify reliable genetic markers for resistance. We demonstrate that dPCR and NGS are robust methods for analysing CNVs and provide cross-validating results, highlighting their utility in the genetic analyses of this parasite.

Multiplex PCR for gastrointestinal parasites in stool: Benchmarking against direct microscopy and simplex PCR.

PURPOSE: To develop and validate a multiplex conventional PCR assay to simultaneously detect Cryptosporidium spp., Entamoeba histolytica, and Giardia lamblia in diarrheal samples as a rapid, cost-effective, and sensitive diagnostic tool for prevalent co-infections for improved diagnostic accuracy and efficiency in resource-limited settings. METHODS: Stool samples collected from patients with gastrointestinal symptoms after taking written consent, processed via wet mount, iodine mount, and PCR assays. Cohen's kappa statistical analysis was done to test agreement. RESULT: Among 240 patients, 28.75% showed intestinal protozoa via Microscopy; Single-plex and multiplex PCR demonstrated 100% concordance, detecting 27.9%; confirmed by sequencing. Highest parasite positivity was observed in transplant and immunocompromised patients, with moderate to almost perfect agreement between microscopy and molecular methods. CONCLUSION: Multiplex-conventional PCR offers superior sensitivity and specificity over microscopy and 100% concordance with single-plex PCR, enabling rapid, cost-effective diagnosis of multiple parasites from single stool sample. Its adoption could revolutionize parasitic infection management in routine diagnostics.

In vitro and in vivo effects of green-synthesized silver nanoparticles against Giardia lamblia infection.

The current experimental study is designed to examine the in vitro and in vivo effects of green synthesized silver nanoparticles (AgNPs) against Giardia lamblia, a major cause of parasitic diarrhea. The precipitation method was employed for the green synthesis of AgNPs by Astragalus ecbatanus aqueous extract. In the, in vitro, Giardia lamblia cysts and trophozoites were exposed to AgNPs at 10, 20, and 40 mg/mL for 10-360 min. The effects of AgNPs on trophozoite plasma membrane and their cytotoxic effects on normal and colon cancer cells were evaluated using Sytox green and MTT assay for cell viability. The in vivo assay included BALB/c mice, infected by Giardia, treated with AgNPs at 10, 15, and 20 mg/kg/day for one week. On the 8th day post-infection, stool examination was conducted to assess the presence of Giardia cysts and the reduction rate. The size distribution of AgNPs ranged between 5 and 80 nm, with the maximum particle size observed at 40-60 nm. AgNPs significantly (P<0.001) increased the mortality of Giardia lamblia trophozoites in a dose-dependent manner. Specifically, AgNPs at concentrations of 200 and 300 µg/mL destroyed Giardia lamblia cysts after 4 and 2 h, respectively. Trophozoites of Giardia lamblia showed more sensitivity to AgNPs compared to cysts. At concentrations of 100, 200, and 300 µg/mL, AgNPs eliminated all trophozoites after 4, 2, and 1 h of treatment, respectively. AgNPs dose-dependently reduced (P<0.001) the parasite load and viability of Giardia lamblia cysts. Exposure of Giardia lamblia trophozoites to AgNPs dose-dependently increased the plasma membrane permeability as indicated by rise in the exposed fluorescence. The CC50 value AgNPs for colon cancer and normal cell lines was 402.3 µg/mL and 819.6 µg/mL, respectively. The selectivity value greater than 2 (2.04), suggests that these AgNPs are safe for normal cells in comparison with cancer cells. This experimental study showed that AgNPs green synthesized by Astragalus ecbatanus exhibited significant in vitro and in vivo anti-Giardia activity, positioning them as potential candidates for Giardia infection treatment. Nevertheless, further research on the precise mechanisms of action and comprehensive exploration of all toxicity aspects associated with this type of AgNPs need to be considered.

The Influence of the Protozoan Giardia lamblia on the Modulation of the Immune System and Alterations in Host Glucose and Lipid Metabolism.

Giardia lamblia, the cause of giardiasis, significantly impacts patients with metabolic disorders related to insulin resistance (IR). Both giardiasis and metabolic disorders share elements such as chronic inflammation and intestinal dysbiosis, which substantially affect the metabolic and cytokine profiles of patients. This review discusses the mechanisms of virulence of G. lamblia, its influence on the immune system, and its association with metabolic disorders. The review aims to show how G. lamblia invasion acts on the immune system and the glucose and lipid metabolism. Key findings reveal that G. lamblia infection, by disrupting intestinal permeability, alters microbiota composition and immune responses, potentially impairing metabolic status. Future research should focus on elucidating the specific mechanisms by which G. lamblia influences the metabolism, exploring the long-term consequences of chronic infection, and developing targeted therapeutic strategies that include both parasitic and metabolic aspects. These insights underscore the need for a multidisciplinary approach to the treatment of giardiasis in patients with metabolic disorders.

Prevalence and assemblage identified of Giardia duodenalis in zoo and farmed Asiatic black bears (Ursus thibetanus) from the Heilongjiang and Fujian Provinces of China.

Captive and free-living wildlife serve as significant hosts for Giardia duodenalis. Asiatic black bears, valued for their economic and medicinal importance, are extensively farmed in China and also prevalent in zoos. However, studies on G. duodenalis in these animals in China are limited. Here, 218 feces samples of Asiatic black bears were collected: 36 from a zoo in Heilongjiang Province, and 182 from a farm in Fujian Province. Nested PCR of the SSU rRNA gene, followed by sequencing, was employed to determine the frequency and assemblage distribution of G. duodenalis. Positive samples underwent further analysis through multilocus genotyping (MLG) by amplifying the genes for glutamate dehydrogenase (gdh), ß-giardin (bg), and triosephosphate isomerase (tpi). Of the 218 samples, G. duodenalis was detected in 22 cases at the SSU rRNA gene locus, including three from Heilongjiang and 19 from Fujian. Three assemblages were identified: A (n = 1), B (n = 16), and E (n = 2) in Fujian; and B (n = 3) in Heilongjiang. Out of the 22 positive samples, 20, 19, and 9 were effectively amplified and sequenced across the tpi, gdh, and bg loci, respectively. Seven samples were genotyped successfully at all three loci, identifying MLG-B1 (n = 1), MLG-B2 (n = 1), and MLG-B3 (n = 1), MLG-B4 (n = 1), MLG-B5 (n = 2), and MLG-B6 (n = 1) as the six assemblage B MLGs. This study marks the first documentation of G. duodenalis in Asiatic black bears in captivity in Fujian and Heilongjiang. The identification of zoonotic assemblages A and B, along with E, underscores potential public health concerns.

Title: Prévalence et assemblages de Giardia duodenalis chez les ours noirs d'Asie (Ursus thibetanus) d'élevage et de zoos dans les provinces chinoises du Heilongjiang et du Fujian. Abstract: Les faunes captive et libre incluent des hôtes importants pour Giardia duodenalis. Les ours noirs d'Asie, appréciés pour leur importance économique et médicinale, sont couramment élevés en Chine et répandus dans les zoos. Cependant, les études sur G. duodenalis chez ces animaux en Chine sont limitées. Ici, 218 échantillons d'excréments d'ours noirs d'Asie ont été collectés, 36 dans un zoo de la province du Heilongjiang et 182 dans une ferme de la province du Fujian. La PCR imbriquée de l'ARNr SSU, suivie d'un séquençage, a été utilisée pour déterminer la fréquence et la distribution des assemblages de G. duodenalis. Les échantillons positifs ont subi une analyse plus approfondie par génotypage multilocus (MLG) en amplifiant les gènes de la glutamate déshydrogénase (gdh), de la ß-giardine (bg) et de la triosephosphate isomérase (tpi). Sur les 218 échantillons, G. duodenalis a été détecté dans 22 cas par le locus du gène de l'ARNr SSU, dont trois du Heilongjiang et 19 du Fujian. Trois assemblages ont été identifiés : A (n = 1), B (n = 16) et E (n = 2) dans le Fujian, et B (n = 3) dans le Heilongjiang. Sur les 22 échantillons positifs, 20, 19 et 9 ont été efficacement amplifiés et séquencés respectivement pour les loci tpi, gdh et bg. Sept échantillons ont été génotypés avec succès sur les trois loci, identifiant MLG-B1 (n = 1), MLG-B2 (n = 1) et MLG-B3 (n = 1), MLG-B4 (n = 1), MLG- B5 (n = 2) et MLG-B6 (n = 1) comme les six assemblages MLG B. Cette étude marque la première investigation de G. duodenalis chez les ours noirs d'Asie en captivité au Fujian et au Heilongjiang. L'identification des assemblages zoonotiques A et B, ainsi que E, souligne des problèmes potentiels de santé publique.

Occurrence and multilocus genotyping of Giardia duodenalis in diarrheic and asymptomatic children from South of Zhejiang province in China.

Giardia duodenalis is an intestinal pathogen that is found globally. Children are more susceptible and often suffer severe consequences after infection. Despite this, the health effects of this pathogen continue to be poorly understood and neglected. In Wenzhou, Zhejiang province, China, stool samples were obtained from 1032 children who were admitted to Yuying Children's Hospital. Out of these, 684 presented with diarrhea, while 348 were asymptomatic. The stool samples were screened for G. duodenali by targeting the small subunit of the ribosomal RNA (SSU rRNA) gene. Subtypes of G. duodenalis were identified via amplification of the glutamate dehydrogenase (gdh), beta-giardin (bg), and triosephosphate isomerase (tpi) genes in samples positive for the G. duodenalis. The findings indicated the presence of G. duodenalis in 0.9 % (9/1032) of the samples, with 9/684 (1.3 %) of the samples originating from children with diarrhea and none from the asymptomatic samples. All 9 samples that tested positive for G. duodenalis were determined to be of assemblage A. Of these, 6 samples were effectively genotyped at all 3 loci, resulting in the identification of 3 distinct MLGs: MLG-AII1 (n = 1), MLG-AII2 (n = 4), and MLG-AII2 (n = 1), all belonging to G. duodenalis assemblage AII. This was the first study that confirmed G. duodenalis infections in children residing in southern Zhejiang, China, with comparatively low rates of infection. The detection of G. duodenalis assemblage AII indicates a possibility of transfer from one human to another. The parasite's effect on the health of young children requires special attention and consideration.

Waterborne Cryptosporidium species and Giardia duodenalis in resources of MENA: A systematic review and meta-analysis.

This review explores our understanding of Cryptosporidium species and Giardia duodenalis distribution in Middle East and North African (MENA) water resources. Results emphasize that Cryptosporidium species (sp.) and G. duodenalis (oo)cysts are present in distinct categories of water in ten MENA countries. Cryptosporidium sp. proportional prevalence in the MENA region was 24.5% (95% CI 16.3-33.8), while G. duodenalis prevalence was 37.7% (95% CI 21.9-55.1). Raw wastewater and surface water were the water categories most significantly impacted. Both parasites were reported in the various types of MENA drinking waters. The most frequent species/genotypes reported were C. hominis, C. parvum, and G. duodenalis assemblage A. Despite the high prevalence of (oo)cysts reported, we should consider the absence of waterborne outbreaks. This indicates significant underestimation and underreporting of both parasites in MENA. Stakeholders should apply water contamination legislation to eradicate Cryptosporidium sp. and G. duodenalis (oo)cysts from water resources/categories.

Risk-based critical concentrations of enteric pathogens for recreational water criteria and recommended minimum sample volumes for routine water monitoring.

Concerns are rising about the contamination of recreational waters from human and animal waste, along with associated risks to public health. However, existing guidelines for managing pathogens in these environments have not yet fully integrated risk-based pathogen-specific criteria, which, along with recent advancements in indicators and markers, are essential to improve the protection of public health. This study aimed to establish risk-based critical concentration benchmarks for significant enteric pathogens, i.e., norovirus, rotavirus, adenovirus, Cryptosporidium spp., Giardia lamblia, Campylobacter jejuni, Salmonella spp., and Escherichia coli O157:H7. Applying a 0.036 risk benchmark to both marine and freshwater environments, the study identified the lowest critical concentrations for children, who are the most susceptible group. Norovirus, C. jejuni, and Cryptosporidium presented lowest median critical concentrations for virus, bacteria, and protozoa, respectively: 0.74 GC, 1.73 CFU, and 0.39 viable oocysts per 100 mL in freshwater for children. These values were then used to determine minimum sample volumes corresponding to different recovery rates for culture method, digital polymerase chain reaction and quantitative PCR methods. The results indicate that for children, norovirus required the largest sample volumes of freshwater and marine water (52.08 to 178.57 L, based on the 5th percentile with a 10 % recovery rate), reflecting its low critical concentration and high potential for causing illness. In contrast, adenovirus and rotavirus required significantly smaller volumes (approximately 0.24 to 1.33 L). C. jejuni and Cryptosporidium, which required the highest sampling volumes for bacteria and protozoa, needed 1.72 to 11.09 L and 4.17 to 25.51 L, respectively. Additionally, the presented risk-based framework could provide a model for establishing pathogen thresholds, potentially guiding the creation of extensive risk-based criteria for various pathogens in recreational waters, thus aiding public health authorities in decision-making, strengthening pathogen monitoring, and improving water quality testing accuracy for enhanced health protection.

Pet chinchillas (Chinchilla lanigera): Source of zoonotic Giardia intestinalis, Cryptosporidium ubiquitum and microsporidia of the genera Encephalitozoon and Enterocytozoon.

The domestic chinchilla (Chinchilla lanigera) is kept as a pet and previous studies suggest that it may play an important role as a source of zoonotic parasites, including Giardia intestinalis, Cryptosporidium spp. and microsporidia. In this study, we examined the occurrence and genetic diversity of above mentioned parasites in pet chinchillas in the Czech Republic by PCR/sequencing of the 18S rRNA, TPI, and ITS genes. Of 149 chinchillas from 24 breeders, 91.3 % were positive for G. intestinalis, 8.1 % for Cryptosporidium spp., 2.0 % for Encephalitozoon spp., and 5.4 % for E. bieneusi. Molecular analyses revealed presence of G. intestinalis assemblage B, C. ubiquitum (XIIa family), E. bieneusi genotypes D, SCF2, and, CHN-F1, and E. intestinalis. The infection intensity of G. intestinalis determined by qRT-PCR reached up to 53,978 CPG, C. ubiquitum up to 1409 OPG, E. intestinalis up to 1124 SPG, and E. bieneusi up to 1373 SPG. Only two chinchillas with C. ubiquitum and five with G. intestinalis had diarrhoea at the time of the screening. Three chinchillas in the long-term study were consistently positive for G. intestinalis, with intermittent excretion of C. ubiquitum, E. intestinalis, and E. bieneusi over 25 weeks. The findings indicate that chinchillas are frequently infected with zoonotic parasitic protists, but that these infections rarely show clinical signs. The lack of visible signs could reduce the vigilance of pet owners when handling their chinchillas, increasing the risk of transmission within breeding groups and possibly to humans.

The epidemiology of intestinal protozoa in the Israeli population based on molecular stool test: a nationwide study.

Stool examination using microscopy was the traditional method for the diagnosis of intestinal parasites. Recently, the use of molecular tests to identify stool protozoa has become the main tool used in most clinical laboratories in Israel. This study aimed to evaluate the prevalence of intestinal parasites in Israel and to compare this prevalence in laboratories that use molecular tests vs a laboratory that uses microscopy. Samples collected from January to October 2021 at seven laboratories were analyzed by real-time PCR (RT-PCR) or by microscopy. The multiplex panel included the following pathogens: Giardia lamblia, Entamoeba histolytica, Cryptosporidium spp., Cyclospora, Dientamoeba fragilis, and Blastocystis spp. Overall, 138,415 stool samples were tested by RT-PCR and 6,444 by microscopy. At least one protozoa species was identified in 28.4% of the PCR-tested samples compared to 4.6% of the microscopy-tested samples. D. fragilis was the most common PCR-identified species (29%). D. fragilis, G. lamblia, and Cryptosporidium spp. were mainly found in pediatric population, while Blastocystis spp. was most prevalent among adults (P < 0.001). In a sub-cohort of 21,480 samples, co-infection was found in 4,113 (19.15%) samples, with Blastocystis spp. and D. fragilis being the most common (14.9%) pair. Molecular stool testing proved more sensitive compared to microscopy. D. fragilis was the most commonly detected pathogen. The above profile was identified during the COVID pandemic when traveling was highly restricted and most likely represents the locally circulating protozoa. IMPORTANCE: This study sheds light on the prevalence of stool parasites in Israel. Additionally, this study indicates that the shift from microscope analysis to molecular tests improved protozoa diagnosis.

Endocytosis in anaerobic parasitic protists.

The incorporation of different molecules by eukaryotic cells occurs through endocytosis, which is critical to the cell's survival and ability to reproduce. Although this process has been studied in greater detail in mammalian and yeast cells, several groups working with pathogenic protists have made relevant contributions. This review analysed the most relevant data on the endocytic process in anaerobic protists (Entamoeba histolytica, Giardia intestinalis, Trichomonas vaginalis, and Tritrichomonas foetus). Many protozoa can exert endocytic activity across their entire surface and do so with great intensity, as with E. histolytica. The available data on the endocytic pathway and the participation of PI-3 kinase, Rab, and Rho molecular complexes is reviewed from a historical perspective.

Microbial Health Risks of Cryptosporidium parvum and Giardia lamblia in Tropical Coastal Water in Araromi, Nigeria.

Objective: Giardia and Cryptosporidium are enteric protozoa that can cause a variety of gastrointestinal diseases, especially in vulnerable people like children, the elderly, and those with impaired immune systems. In order to ascertain the microbiological quality of the recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. This risk assessment is of great significance to human health protection against waterborne diseases. The aim of this study was to determine the microbial quality of recreational water from Araromi Beach in Ilaje Local Government Area, Ondo State, Nigeria. Methods: Microscopic examination of Cryptosporidium and Giardia oocysts were done. Results: Results revealed maximum occurrence of Cryptosporidium parvum (20 oocysts/100 mL) of water sample in the month of April and maximum occurrence of Giardia lamblia (300 cysts/100 mL) of water sample in the month of June. Additionally, according to Kolmogorov-Smirnov tests for normalcy Ho =0.05, Giardia lamblia and Cryptosporidium parvum were not regularly distributed in the water samples collected from the beach throughout the study period. The average likelihood of contracting Giardia lamblia and Cryptosporidium parvum infections after consuming 100 mL of beach water was 0.96 and 0.35, respectively. The risks of infection associated with Cryptosporidium parvum was lower than those associated with Giardia lamblia in water from the beach, but were both above the acceptable risk limit of 10-4. Conclusion: The results of this study indicate that Giardia and Cryptosporidium may represent serious health hazards to people who engage in aquatic activities. Adopting a comprehensive strategy that includes regular inspections, enhanced detection techniques, and the prevention of aquatic environment pollution may provide clean and safe recreational water for all, thereby safeguarding the public's health.

Giardia lamblia Immunoassay: Systematic review and meta-analysis.

Immunoassays are important tools in diagnosing giardiasis, though there are several controversies inherent in the existing methods. We conducted a systematic review and meta-analysis to assess the pooled diagnostic accuracy of immunoassays in detecting the gastrointestinal disease-causing parasite Giardia lamblia. Our comprehensive search, which included PubMed, Scopus, and ScienceDirect from 2000 up until 2023, resulted in 34 studies reporting the performance of 24 different immunoassays. The overall pooled sensitivity and specificity of immunoassays and subgroup analyses were determined. Notably, ImmunoCardSTAT® and RIDASCREEN® Giardia were the most used assays (n = 6 studies each). They exhibited sensitivity and specificity of 84 % and 99 % and 93 % and 99 %, respectively. Sub-group analysis on the type of immunoassays (without the case-control studies) showed that commercial ELISA had higher sensitivity (96 %) compared to a commercial immunochromatographic (88 %), which justifies the difference of sensitivity between ImmunoCardSTAT® and RIDASCREEN® Giardia. However, the applicability between these two in clinical settings, replacing the gold standard, should be considered including the time, equipment requirement, and budget. Samples from symptomatic patients showed higher sensitivity (92 %) compared to asymptomatic patients (79 %). Overall, immunoassays can be a practical replacement for the current gold standard, but more information should be gathered regarding the cost of providing more conclusive suggestions on these findings.

Correlation between Melatonin and Colostral Regulatory T Cells in Giardia lamblia Infection.

Giardiasis is a parasitic disease caused by Giardia lamblia (G. lamblia) that affects people worldwide. Still, few studies report on the immunoregulatory effects of the biomolecules of colostrum during interactions with G. lamblia. This study aimed to assess the concentrations of melatonin and cortisol hormones, the percentage of Treg cells, and the levels of cytokines IL-10 and TGF-ß in colostrum from mothers who tested positive for the parasite. This cross-sectional study analyzed colostrum samples from 25 puerperal. The samples were tested using an ELISA to determine if they were seropositive for G. lamblia and the type of antibody present (IgM and IgG). Based on the results, the samples were divided into three groups: a control group (N = 10) with no reaction to either IgM or IgG, a group seropositive for IgG (IgG+/IgM-; N = 8), and a group seropositive for IgM (IgM+/IgG-; N = 7). The concentrations of melatonin and cortisol were measured using the ELISA method. Additionally, cytokines IL-10 and TGF-ß and immunophenotyping were analyzed using flow cytometry. In the group that tested positive for IgM anti-G. lamblia, the concentration of melatonin was lower. However, in the colostrum from mothers who tested positive for IgG anti-G. lamblia, the level of this hormone had increased. The cortisol levels were similar between the groups, regardless of seropositivity. There was a higher percentage of Treg cells in the colostrum from mothers who tested positive for IgM anti-G. lamblia. TGF-ß levels also increased in the colostrum of mothers who tested positive for IgM anti-G. lamblia. In the seronegative group for G. lamblia, there was a positive correlation between melatonin concentration and the percentage of Treg cells. These data suggest that the increase in regulatory cells and cytokines and the reduction in melatonin in colostrum from mothers with recent giardia infection may contribute to the evolution and manifestation of the disease.

Unveiling the presence and genotypic diversity of Giardia duodenalis on large-scale sheep farms: insights from the Henan and Ningxia Regions, China.

BACKGROUND: The parasitic protozoan Giardia duodenalis is an important cause of diarrheal disease in humans and animals that can be spread by fecal-oral transmission through water and the environment, posing a challenge to public health and animal husbandry. Little is known about its impact on large-scale sheep farms in China. In this study we investigated G. duodenalis infection of sheep and contamination of the environment in large-scale sheep farms in two regions of China, Henan and Ningxia. METHODS: A total of 528 fecal samples, 402 environmental samples and 30 water samples were collected from seven large-scale sheep farms, and 88 fecal samples and 13 environmental samples were collected from 12 backyard farms. The presence of G. duodenalis was detected by targeting the ß-giardin (bg) gene, and the assemblage and multilocus genotype of G. duodenalis were investigated by analyzing three genes: bg, glutamate dehydrogenase (gdh) and triphosphate isomerase (tpi). RESULTS: The overall G. duodenalis detection rate was 7.8%, 1.4% and 23.3% in fecal, environmental and water samples, respectively. On the large-scale sheep farms tested, the infection rate of sheep in Henan (13.8%) was found to be significantly higher than that of sheep in Ningxia (4.2%) (P < 0.05). However, the difference between the rates of environmental pollution in Henan (1.9%) and Ningxia (1.0%) was not significant (P > 0.05). Investigations of sheep at different physiological stages revealed that late pregnancy ewes showed the lowest infection rate (1.7%) and that young lambs exhibited the highest (18.8%). Genetic analysis identified G. duodenalis belonging to two assemblages, A and E, with assemblage E being dominant. A total of 27 multilocus genotypes were identified for members of assemblage E. CONCLUSIONS: The results suggest that G. duodenalis is prevalent on large-scale sheep farms in Henan and Ningxia, China, and that there is a risk of environmental contamination. This study is the first comprehensive examination of the presence of G. duodenalis on large-scale sheep farms in China. Challenges posed by G. duodenalis to sheep farms need to be addressed proactively to ensure public health safety.

Postnatal zinc deficiency due to giardiasis disrupts hippocampal and cerebellar development.

BACKGROUND: Giardiasis and zinc deficiency have been identified as serious health problems worldwide. Although Zn depletion is known to occur in giardiasis, no work has investigated whether changes occur in brain structures. METHODS: Three groups of gerbils were used: control (1), orogastrically inoculated on day 3 after birth with trophozoites of two isolates of Giardia intestinalis (HGINV/WB) group (2 and 3). Estimates were made at five ages covering: establishment of infection, Giardia population growth, natural parasite clearance and a post-infection age. QuantiChrome zinc assay kit, cresyl violet staining and TUNEL technique were used. RESULTS: A significant decrease (p<0.01) in tissue zinc was observed and persisted after infection. Cytoarchitectural changes were observed in 75% of gerbils in the HGINV or WB groups. Ectopic pyramidal neurons were found in the cornus ammonis (CA1-CA3). At 60 and 90 days of age loss of lamination was clearly visible in CA1. In the dentate gyrus (DG), thinning of the dorsal lamina and abnormal thickening of the ventral lamina were observed from 30 days of age. In the cerebellum, we found an increase (p<0.01) in the thickness of the external granular layer (EGL) at 14 days of age that persisted until day 21 (C 3 ± 0.3 µm; HGINV 37 ± 5 µm; WB 28 ± 3 µm); Purkinje cell population estimation showed a significant decrease; a large number of apoptotic somas were observed scattered in the molecular layer; in 60 and 90 days old gerbils we found granular cell heterotopia and Purkinje cell ectopia. The pattern of apoptosis was different in the cerebellum and hippocampus of parasitized gerbils. CONCLUSION: The morphological changes found suggest that neuronal migration is affected by zinc depletion caused by giardiasis in early postnatal life; for the first time, the link between giardiasis-zinc depletion and damaged brain structures is shown. This damage may explain the psychomotor/cognitive delay associated with giardiasis. These findings are alarming. Alterations in zinc metabolism and signalling are known to be involved in many brain disorders, including autism.

Coexistence of Helicobacter pylori and Giardia duodenalis causes severe iron deficiency anaemia in an adult male: a case report.

INTRODUCTION: Iron deficiency anaemia (IDA), the most prevalent type of anaemia, is recognised as a significant global health concern that affects individuals of all ages. CASE PRESENTATION: Herein, we present a case involving an adult male coinfected with Helicobacter pylori and Giardia duodenalis, which precipitated severe IDA. RESULTS: A 24-year-old male presented with symptoms including fatigue, dizziness, headache, abdominal pain, and diarrhoea persisting for four weeks. Thorough blood tests, including complete blood counts, blood film, and iron studies, conclusively established the presence of severe IDA. Furthermore, his faecal sample was collected and subjected to analysis of common bacterial and parasitic gastrointestinal infections. Examination of upper and lower gastrointestinal pathogens indicated that the severe IDA was most likely a result of coinfection with H. pylori and G. duodenalis. The patient received treatment involving antibiotics and iron replacement therapy, which resulted in an improvement in both his symptoms and laboratory results. CONCLUSIONS: The present report provides crucial insights into the synergistic effect of concurrent H. pylori and G. duodenalis infections, highlighting their potential to induce severe IDA in infected patients.

Lysine methyltransferase 2 plays a key role in the encystation process in the parasite Giardia lamblia.

Histone post-translational modifications are extensively studied for their role in regulating gene transcription and cellular environmental adaptation. Research into these modifications has recently begun in the protozoan parasite Giardia lamblia, focusing on histone-modifying enzymes and specific post-translational changes. In the transformation from the trophozoite to the cyst form in the life cycle of this parasite, significant morphological and genetic alterations occur, culminating in the synthesis of cyst wall proteins responsible for forming the protective cyst wall. It has been previously demonstrated that histone deacetylation is required during encystation and that the enzyme lysine methyltransferase 1 is involved in the upregulation of encystation. Our study aims to extend the analysis to lysine methyltransferase 2 (GlKMT2) function. For this, two constructs were generated: one that downregulate the expression of GLKMT2 via antisense (glkmt2-as transgenic cells) and the other overexpressing GlKMT2 (glkmt2-ha transgenic cells). We found that the glktm2-as transgenic cells showed an arrest in progress at the late encystation stage. Consequently, the number of cysts produced was lower than that of the control cells. On the other hand, we found that the overexpression of GlKMT2 acts as a negative mutant of the enzyme. In this way, these glktm2-ha transgenic cells showed the same behavior during growth and encystation as glkmt2-as transgenic cells. This interplay between different enzymes acting during encystation reveals the complex process behind the differentiation of the parasite. Understanding how these enzymes play their role during the encystation of the parasite would allow the design of inhibitors to control the parasite.