We aimed to assess the risks of
China ; Cryptosporidiosis/microbiology* ; Cryptosporidium/isolation & purification* ; Giardia/isolation & purification* ; Giardiasis/microbiology* ; Humans ; Risk Assessment ; Water Microbiology ; Water Supply/statistics & numerical data*

Innate lymphoid cells (ILCs) are key players during an immune response at the mucosal surfaces, such as lung, skin, and gastrointestinal tract. Giardia lamblia is an extracellular protozoan pathogen that inhabits the human small intestine. In this study, ILCs prepared from the lamina propria of mouse small intestine were incubated with G. lamblia trophozoites. Transcriptional changes in G. lamblia-exposed ILCs resulted in identification of activation of several immune pathways. Secretion of interleukin (IL)-17A, IL-17F, IL-1β, and interferon-γ was increased, whereas levels of IL-13, IL-5, and IL-22, was maintained or reduced upon exposure to G. lamblia. Goup 3 ILC (ILC3) was found to be dominant amongst the ILCs, and increased significantly upon co-cultivation with G. lamblia trophozoites. Oral inoculation of G. lamblia trophozoites into mice resulted in their presence in the small intestine, of which, the highest number of parasites was detected at the 5 days-post infection. Increased ILC3 was observed amongst the ILC population at the 5 days-post infection. These findings indicate that ILC3 from the lamina propria secretes IL-17 in response to G. lamblia, leading to the intestinal pathology observed in giardiasis.
Animals ; Gastrointestinal Tract ; Giardia lamblia ; Giardia ; Giardiasis ; Humans ; Interleukin-13 ; Interleukin-17 ; Interleukin-5 ; Interleukins ; Intestine, Small ; Lung ; Lymphocytes ; Mice ; Mucous Membrane ; Parasites ; Pathology ; Skin ; Trophozoites

Giardia lamblia, an anaerobic, amitochondriate protozoan parasite causes parasitic infection giardiasis in children and young adults. It produces pyruvate, a major metabolic product for its fermentative metabolism. The current study was undertaken to explore the effects of pyruvate as a physiological antioxidant during oxidative stress in Giardia by cysteine-ascorbate deprivation and further investigation upon the hypothesis that oxidative stress due to metabolism was the reason behind the cytotoxicity. We have estimated intracellular reactive oxygen species generation due to cysteine-ascorbate deprivation in Giardia. In the present study, we have examined the effects of extracellular addition of pyruvate, during oxidative stress generated from cysteine-ascorbate deprivation in culture media on DNA damage in Giardia. The intracellular pyruvate concentrations at several time points were measured in the trophozoites during stress. Trophozoites viability under cysteine-ascorbate deprived (CAD) medium in presence and absence of extracellular pyruvate has also been measured. The exogenous addition of a physiologically relevant concentration of pyruvate to trophozoites suspension was shown to attenuate the rate of ROS generation. We have demonstrated that Giardia protects itself from destructive consequences of ROS by maintaining the intracellular pyruvate concentration. Pyruvate recovers Giardia trophozoites from oxidative stress by decreasing the number of DNA breaks that might favor DNA repair.
Child ; Culture Media ; DNA Breaks ; DNA Damage ; DNA Repair ; Giardia lamblia ; Giardia ; Giardiasis ; Humans ; Metabolism ; Oxidative Stress ; Parasites ; Pyruvic Acid ; Reactive Oxygen Species ; Trophozoites ; Young Adult

Laboratory workers, in resource-poor countries, still consider PCR detection of Giardia lamblia more costly and more time-consuming than the classical parasitological techniques. Based on 2 published primers, an in-house one-round touchdown PCR-RFLP assay was developed. The assay was validated with an internal amplification control included in reactions. Performance of the assay was assessed with DNA samples of various purities, 91 control fecal samples with various parasite load, and 472 samples of unknown results. Two cysts per reaction were enough for PCR detection by the assay with exhibited specificity (Sp) and sensitivity (Se) of 100% and 93%, respectively. Taking a published small subunit rRNA reference PCR test results (6%; 29/472) as a nominated gold standard, G. lamblia was identified in 5.9% (28/472), 5.2%, (25/472), and 3.6% (17/472) by PCR assay, RIDA® Quick Giardia antigen detection test (R-Biopharm, Darmstadt, Germany), and iodine-stained smear microscopy, respectively. The percent agreements (kappa values) of 99.7% (0.745), 98.9% (0.900), and 97.7% (0.981) were exhibited between the assay results and that of the reference PCR, immunoassay, and microscopy, respectively. Restriction digestion of the 28 Giardia-positive samples revealed genotype A pattern in 12 and genotype B profile in 16 samples. The PCR assay with the described format and exhibited performance has a great potential to be adopted in basic clinical laboratories as a detection tool for G. lamblia especially in asymptomatic infections. This potential is increased more in particular situations where identification of the parasite genotype represents a major requirement as in epidemiological studies and infection outbreaks.
DNA, Protozoan/genetics ; Developing Countries ; Feces/parasitology ; Genotype ; Giardia lamblia/genetics ; Giardiasis/*diagnosis ; Humans ; Microscopy ; Parasitology/economics/instrumentation/*methods ; *Polymerase Chain Reaction ; *Polymorphism, Restriction Fragment Length ; Reproducibility of Results ; Sensitivity and Specificity

The objective of this study was to genetically characterize isolates of Giardia duodenalis and to determine if zoonotic potential of G. duodenalis could be found in stray cats from urban and suburban environments in Guangzhou, China. Among 102 fresh fecal samples of stray cats, 30 samples were collected in Baiyun district (urban) and 72 in Conghua district (suburban). G. duodenalis specimens were examined using light microscopy, then the positive specimens were subjected to PCR amplification and subsequent sequencing at 4 loci such as glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), beta-giardin (bg), and small subunit ribosomal RNA (18S rRNA) genes. The phylogenetic trees were constructed using obtained sequences by MEGA5.2 software. Results show that 9.8% (10/102) feline fecal samples were found to be positive by microscopy, 10% (3/30) in Baiyun district and 9.7% (7/72) in Conghua district. Among the 10 positive samples, 9 were single infection (8 isolates, assemblage A; 1 isolate, assemblage F) and 1 sample was mixed infection with assemblages A and C. Based on tpi, gdh, and bg genes, all sequences of assemblage A showed complete homology with AI except for 1 isolate (CHC83). These findings not only confirmed the occurrence of G. duodenalis in stray cats, but also showed that zoonotic assemblage A was found for the first time in stray cats living in urban and suburban environments in China.
Animals ; Cat Diseases/*parasitology ; Cats ; China ; Cluster Analysis ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Feces/parasitology ; Giardia lamblia/*classification/cytology/genetics/*isolation & purification ; Giardiasis/parasitology/*veterinary ; Microscopy ; Molecular Sequence Data ; Phylogeny ; Protozoan Proteins/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA

The objective of this study was to genetically characterize isolates of Giardia duodenalis and to determine if zoonotic potential of G. duodenalis could be found in stray cats from urban and suburban environments in Guangzhou, China. Among 102 fresh fecal samples of stray cats, 30 samples were collected in Baiyun district (urban) and 72 in Conghua district (suburban). G. duodenalis specimens were examined using light microscopy, then the positive specimens were subjected to PCR amplification and subsequent sequencing at 4 loci such as glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), beta-giardin (bg), and small subunit ribosomal RNA (18S rRNA) genes. The phylogenetic trees were constructed using obtained sequences by MEGA5.2 software. Results show that 9.8% (10/102) feline fecal samples were found to be positive by microscopy, 10% (3/30) in Baiyun district and 9.7% (7/72) in Conghua district. Among the 10 positive samples, 9 were single infection (8 isolates, assemblage A; 1 isolate, assemblage F) and 1 sample was mixed infection with assemblages A and C. Based on tpi, gdh, and bg genes, all sequences of assemblage A showed complete homology with AI except for 1 isolate (CHC83). These findings not only confirmed the occurrence of G. duodenalis in stray cats, but also showed that zoonotic assemblage A was found for the first time in stray cats living in urban and suburban environments in China.
Animals ; Cat Diseases/*parasitology ; Cats ; China ; Cluster Analysis ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Feces/parasitology ; Giardia lamblia/*classification/cytology/genetics/*isolation & purification ; Giardiasis/parasitology/*veterinary ; Microscopy ; Molecular Sequence Data ; Phylogeny ; Protozoan Proteins/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA

Giardia lamblia infection, giardiasis, is the leading waterborne diarrhea-causing disease. It is common in most countries of the world, including South Korea and Japan. Giardia lamblia can cause asymptomatic infection but also acute abdominal discomfort with diarrhea. In addition, it may lead to chronic diarrhea associated with villous atrophy and impaired epithelial barrier in the small intestine. In the present case, a 45-year-old woman presented with lower abdominal discomfort in the absence of diarrhea. Colonoscopy showed diffuse mucosal edema, erythema, and erosions with exudate in the cecum and ascending colon. Colonoscopic biopsy and stool examination revealed trophozoites of Giardia lamblia. Colitis resolved after metronidazole therapy. Our case suggests that giardiasis should be included in the differential diagnosis of colitis, even if the patient does not present with diarrhea.
Asymptomatic Infections ; Atrophy ; Biopsy ; Cecum ; Colitis* ; Colon, Ascending ; Colonoscopy ; Diagnosis, Differential ; Diarrhea ; Edema ; Erythema ; Exudates and Transudates ; Female ; Giardia lamblia* ; Giardia* ; Giardiasis ; Humans ; Intestine, Small ; Japan ; Korea ; Metronidazole ; Middle Aged ; Trophozoites

Giardia is a major public health concern and considered as reemerging in industrialized countries. The present study investigated the prevalence of giardiosis in 202 sheltered dogs using PCR. The infection rate was 33.2% (67/202); Gyeongsangbuk-do and Daejeon showed 25.7% (39/152, P<0.0001) and 56% (28/50), respectively. The prevalence of infected female dogs (46.7%, P<0.001) was higher than in male dogs (21.8%). A higher prevalence (43.5%, P<0.0001) was observed in mixed breed dogs than purebred (14.1%). Although most of the fecal samples collected were from dogs of > or =1 year of age which showed only 27.4% positive rate, 61.8% (P<0.001) of the total samples collected from young animals (<1 year of age) were positive for G. intestinalis. A significantly higher prevalence in symptomatic dogs (60.8%, P<0.0001) was observed than in asymptomatic dogs (23.8%). Furthermore, the analysis of nucleotide sequences of the samples revealed that G. intestinalis Assemblages A and C were found in the feces of dogs from Gyeongsangbuk-do and Daejeon. Since G. intestinalis Assemblage A has been known to infect humans, our results suggest that dogs can act as an important reservoir of giardiosis in Korea. Hence, hygienic management should be given to prevent possible transmission to humans.
Animals ; Base Sequence ; Dog Diseases/epidemiology/*parasitology ; Dogs ; Feces/parasitology ; Female ; Genotype ; Giardia/classification/genetics/*isolation & purification ; Giardiasis/epidemiology/parasitology/*veterinary ; Male ; Molecular Sequence Data ; Protozoan Proteins/genetics ; Republic of Korea/epidemiology

Non-human primates (NHPs) are confirmed as reservoirs of Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi. In this study, 197 fresh fecal samples from 8 NHP species in Qinling Mountains, northwestern China, were collected and examined using multilocus sequence typing (MLST) method. The results showed that 35 (17.8%) samples were positive for tested parasites, including Cryptosporidium spp. (3.0%), G. intestinalis (2.0%), and E. bieneusi (12.7%). Cryptosporidium spp. were detected in 6 fecal samples of Macaca mulatta, and were identified as C. parvum (n=1) and C. andersoni (n=5). Subtyping analysis showed Cryptosporidium spp. belonged to the C. andersoni MLST subtype (A4, A4, A4, and A1) and C. parvum 60 kDa glycoprotein (gp60) subtype IId A15G2R1. G. intestinalis assemblage E was detected in 3 M. mulatta and 1 Saimiri sciureus. Intra-variations were observed at the triose phosphate isomerase (tpi), beta giardin (bg), and glutamate dehydrogenase (gdh) loci, with 3, 1, and 2 new subtypes found in respective locus. E. bieneusi was found in Cercopithecus neglectus (25.0%), Papio hamadrayas (16.7%), M. mulatta (16.3%), S. sciureus (10%), and Rhinopithecus roxellana (9.5%), with 5 ribosomal internal transcribed spacer (ITS) genotypes: 2 known genotypes (D and BEB6) and 3 novel genotypes (MH, XH, and BSH). These findings indicated the presence of zoonotic potential of Cryptosporidium spp. and E. bieneusi in NHPs in Qinling Mountains. This is the first report of C. andersoni in NHPs. The present study provided basic information for control of cryptosporidiosis, giardiasis, and microsporidiosis in human and animals in this area.
Animals ; China ; Cryptosporidiosis/*parasitology ; Cryptosporidium/classification/genetics/*isolation & purification ; Enterocytozoon/classification/genetics/*isolation & purification ; Feces/parasitology ; Female ; Genotype ; Giardia lamblia/classification/genetics/*isolation & purification ; Giardiasis/parasitology/*veterinary ; Male ; Microsporidiosis/parasitology/*veterinary ; Molecular Sequence Data ; Phylogeny ; Primate Diseases/*parasitology ; Primates/classification/parasitology

This study aimed to identify the assemblages (or subassemblages) of Giardia duodenalis by using normal or nested PCR based on 4 genetic loci: glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), beta-giardin (bg), and small subunit ribosomal DNA (18S rRNA) genes. For this work, a total of 216 dogs' fecal samples were collected in Guangdong, China. The phylogenetic trees were constructed with MEGA5.2 by using the neighbor-joining method. Results showed that 9.7% (21/216) samples were found to be positive; moreover, 10 samples were single infection (7 isolates assemblage A, 2 isolates assemblage C, and 1 isolate assemblage D) and 11 samples were mixed infections where assemblage A was predominant, which was potentially zoonotic. These findings showed that most of the dogs in Guangdong were infected or mixed-infected with assemblage A, and multi-locus sequence typing could be the best selection for the genotype analysis of dog-derived Giardia isolates.
Animals ; China ; Cluster Analysis ; Coinfection/parasitology/veterinary ; Cytoskeletal Proteins/genetics ; DNA, Protozoan/chemistry/genetics ; Dog Diseases/parasitology ; Dogs ; Genotype ; Giardia lamblia/*classification/*genetics/isolation & purification ; Giardiasis/parasitology/*veterinary ; Glutamate Dehydrogenase/genetics ; Molecular Sequence Data ; *Multilocus Sequence Typing ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 18S/genetics ; Triose-Phosphate Isomerase/genetics