• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.513-521
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• 2017

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0-4 years, less in adults <40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P<0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.309-315
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• 2022

Inflammatory bowel disease (IBD) is a chronic and recurrent illness of the gastrointestinal tract. Treatment of IBD traditionally involves the use of aminosalicylic acid and steroids, while these drugs has been associated with untoward effects and refractoriness. The absence of effective treatment regimen against IBD has led to the exploration of new targets. Parasites are promising as an alternative therapy for IBD. Recent studies have highlighted the use of parasite-derived substances, such as excretory secretory products, extracellular vesicles (EVs), and exosomes, for the treatment of IBD. In this report, we examined whether EVs secreted by Giardia lamblia could prevent colitis in a mouse model. G. lamblia EVs (GlEVs) were prepared from in vitro cultures of Giardia trophozoites. Clinical signs, microscopic colon tissue inflammation, and cytokine expression levels were detected to assess the effect of GlEV treatment on dextran sulfate sodium (DSS)-induced experimental murine colitis. The administration of GlEVs prior to DSS challenge reduced the expression levels of pro-inflammatory cytokines, including tumor necrosis factor alpha, interleukin 1 beta, and interferon gamma. Our results indicate that GlEV can exert preventive effects and possess therapeutic properties against DSS-induced colitis.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.429-433
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• 2000

Giardia lamblia, a human pathogen causing outbreaks of diarrhea, recently became a focus of great concerns in the fields of both medical and environmental microbioloty. To develop the experimental tools to study giardiasis, encystation, one of the major processes in its life cycle, was reconstituted by inducing an axenic culture of a flagellated form of G. lamblia into a cyst from under high concentration of bile and alkaline pH condition. The successful induction was confirmed by Northern analysis of resulting increased expression of the CWPl gene encoding the cyst wall protein 1. An examination of the encystation process with SEM (scanning electron microscopy) and TEM (transmission electron microscopy) revealed that the trophozoite, a flagellate with a bilateral symmetry, was transformed to a cyst form with an oval-shape and defined filamentous wall. The encystation was found to cause a disappearance of the flagella and an invagination of the adhesive disc. An extensive formation of rER (rough endoplasmic reticulum) was observed after 24h of induction, indication an active synthesis and export of proteins during this process. The vital staining of the invitro-induced systs showed that most cysts maintained their viability.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.287-291
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• 2009

The ${\alpha}/{\beta}$-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant ${\alpha}$-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of ${\alpha}$-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the ${\alpha}$-tubulin gene from G. lamblia. PCR-RFLP analysis of this ${\alpha}$-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B.Theresults indicate that ${\alpha}$-tubulin can be used as a molecular probe to detect G.lamblia.

• Parasites, Hosts and Diseases
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• v.40 no.3
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• pp.131-138
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• 2002

The cyclophilins (Cyps) are family members of proteins that exhibit peptidylprolyl cis-trans isomerase (PPIase, EC 5.2.1.8) activity and bind the immunosuppressive agent cyclosprin A (CsA) in varying degrees. During the process of random sequencing of a cDNA library made from Giardia intestinalis WB strain, the cyclophilin gene (gicypl) was isolated. An open reading frame of gicyp1 gene was 576 nucleotides, which corresponded to a translation product of 176 amino acids (Gicypl). The identity with other Cyps was about 58-71%. The 13 residues that constituted the CsA binding site of human cyclophilin were also detected in the amino acid sequence of Gicypl, including tryptophan residue essential for the drug binding. The single copy of the gicypl gene was detected in the G. intestinalis chromosome by southern hybridization analysis. Recombinant Gicyp 1 protein clearly accelerated the rate of cis ${\rightarrow}$ trans isomerization of the peptide substrate and the catalysis was completely inhibited by the addition of $0.5{\;}{\mu}M$ CsA.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.529-531
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• 2000

Giardia lamblia, a waterborne parasitic protozoa causing diarrhea and gastroenteritis, is transmitted to humans from untreated and treated water in the form of cysts. The ingestion of G. lamblia cysts is followed by the excystation of the cysts to trophozoites and subsequent colonization of the upper small intestine. In this study, the in vitro conditions for upper small intestine. In this study, the in vitro conditions for G. lamblia encystation were investigated to enhance the efficiency of cyst conversion and the resulting cyst density. The trophozoite of G. lamblia was cultivated to the late exponential growth phase, resulting in a high density of over $6{\times}10^7{\;}cells/ml$. The effects of pH, bile content, and induction time were evaluated; A cyst conversion of over 25% and 107 time were evaluated; A cyst conversion of over 25% and 107 cysts/ml were routinely obtained using the optimized encystation conditions including a slightly slkaline pH, 10 to 15 mg/ml of bile concentration, and 48-50 h of induction time.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.95-99
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• 2001

Giardia lamblia is a parasitic protozoa which is transmitted in the form of a cyst through untreated water and also treated drinking water. Since its presence in water has led to frequent outbreaks of giardiasis and death in many countries, the removal and disinfection of this protozoan cyst from the water supply are of great concern for public health. This study examined the disinfection characteristics of G. lamblia cysts isolated from a Korean patient with giardiasis. When using sodium hypochlorite including 5 or 10 ppm chlorine, the killing rate was initially rapid, however, the disinfection slowed down and a 3log reduction could not be achieved even after 2h. The disinfection effectiveness was also reduced at a lower temperature, thereby implying that the risk o a giardiasis outbreak will be higher in the winter season. A CT (concentration$.$time) curve was constructed based on the results with sodium hypochlorite for use in designing and predicting disinfection performance. The organic chlorination disinfectant SDIS (sodium dichloroisocyanurate) produced a lower pH and a much higher residual effect than sodium hypochlorite. The disinfection of cysts by SDIC continued steadily throughout 2h of contact, although the initial killing rate was lower than that with sodium hypochlorite.

• Korean Journal of Veterinary Service
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• v.43 no.4
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• pp.217-225
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• 2020

This study was conducted to survey pathogens of canine coronavirus (CCV), canine distemper virus (CDV), canine influenza virus (CIV), canine parvovirus (CPV), severe fever with thrombocytopenia syndrome virus (SFTSV), Dirofilaria (D.) immitis, Giardia and antibodies against Anaplasma (A.) phagocytophilum, Borrelia (B.) burgdorferi, Brucella (B.) canis and Ehrlichia (E.) canis among stray dogs in Gyeonggi province. We collected 271 feces, 291 bloods, 311 nasal and ocular swab samples from 311 of dogs in the Gyeonggi province assistance dogs sharing center from January to December, 2019. Among canine infectious disease pathogens, Giardia was highly detected in 46/271 (17.0%) samples. Subsequently, CCV 10.3% (28/271), D. immitis 8.2% (24/291), CPV 4.1% (11/271), CDV 1.0% (3/311), A. phagocytophilum (antibody) 0.3% (1/291), E. canis (antibody) 0.3% (1/291) were detected. Based on the results, this study is expected to provide a useful reference for disease control and management of stray dogs.

• Korean Journal of Veterinary Service
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• v.46 no.1
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• pp.47-58
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• 2023

Between February 2020 and September 2021, 378 calves with diarrhea were investigated across 96 cattle breeding farms in Korea, using a rapid diagnostic kit. The study examined the infection rates of major pathogens causing diarrhea in calves, which were categorized by season, age, birth month, and region. Additionally, logistic regression analysis was conducted to investigate the factors affecting the infection rate. The study found that the five representative pathogens causing calf diarrhea exhibited differences in infection rates based on season, region, age, and birth month. Bovine rotavirus, bovine coronavirus, Cryptosporidium, and Giardia commonly exhibited varying risks of infection based on season and age. Furthermore, in addition to these risk factors, bovine rotavirus and Cryptosporidium were found to impact the infection risk of each pathogen by region, while Giardia was found to be affected by birth month.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.201-209
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• 2022

An epidemiological study was conducted to investigate five diarrhea-causing pathogens (coronavirus, rotavirus, E. coli, Cryptosporidium, Giardia) using a rapid diagnostic kit in Hanwoo calves with diarrhea in Chungcheongbuk-do, Korea, from 2018 to 2021. A total of 22,417 fecal samples were collected from calves under 1 year of age; of those, 13,518 (60.3%) were positive for five bovine diarrhea antigens. The antigen positivity rates for rotavirus, coronavirus, E. coli, Giardia, and Cryptosporidium were 34.5%, 11.0%, 8.2%, 4.7%, and 2.0%, respectively. The prevalence of the five pathogens in calves was statistically higher in autumn and winter. The highest prevalence of the pathogens was observed in the under 1 month age group, and the incidence of diarrhea decreased with age. Rotavirus was a major pathogen in calves under 1 month of age, whereas the prevalence of E. coli increased with age. This study provides epidemiological evidence of the prevalence of calf diarrheal pathogens in Chungcheongbuk-do, Korea, which will facilitate early diagnosis and development of measures against calf diarrhea.