As many Koreans now travel abroad, they are at increased risk for a variety of infectious diseases that are endemic to developing countries in the tropics and subtropics. We report two cases of co-infection with Giardia lamblia and Salmonella species not susceptible to nalidixic acid, after travel abroad.
Coinfection ; Communicable Diseases ; Developing Countries ; Giardia ; Giardia lamblia ; Nalidixic Acid ; Salmonella

The present study has been designed as a basic study on laboratory diagnosis of giardiasis and to demonstrate a more effective method for the detection of Giardia lamblia cyst with the inherent advantages of minimizing both the number of stool examinations required and the interval of stool collections for estimating the real state of prevalence in the shortest time possible. There were 3 subject groups of 75 children each currently residing in an orphanage in Gunsan city, Jeonbuk province from which stool specimens were collected every day, every other day, and every 3 days. The procedure is as follows: Resuspend the fixed sample after fixation with SAF solution. Centrifuge the sediment for 1 min. at 2,000 rpm after straining through gauze into a tube. Divide the sediment into 3 parts and use them for direct fecal smear, formalin-ether concentration (MGL) and zinc sulfate (ZnSO(4)) floatation techniques. The results are summarized as follows: Overall infection rate after 10 trials showed a 60 percent positive indication. The positive rate among children under 4 years old was significantly higher than the rate in children over 4 years old. No significant difference in rate by sex was observed. The results of examinations by direct fecal smear and MGL techniques appeared more accurate than that obtained by ZnSO(4) floatation method as indicated by a higher positive rate. Of all three methods concerned, combinations of two demonstrated a higher positive rate than that shown by any one alone. In three consecutive examinations under varying conditions such as different days, the cyst detection rate by MGL technique indicated 83 percent. In 5 examinations under the same varying conditions, the indicated rate was 94 percent. The interval of stool collection proved to be insignificant for the cyst detection rate. In conclusion, both MGL method and modified fecal direct smear can provide a good cyst detection rate of G. lamblia provided that more than 3 consecutive examinations of stool under varying conditions are carried out.
parasitology-protozoa ; Giardia lamblia ; diagnosis ; ormalin ; ether ; zinc sulfate

Conventional formalin-ether concentration method is a gold standard for the diagnosis of parasite infection. However, it may be time-consuming and laborious. We aimed to reveal the clinical usefulness of a modified formalin-ether concentration method using the Para Tube (KS Corporation, Korea) compared with the conventional method. A total of 117 fresh, unpreserved fecal samples composed to 90 negative controls and 27 positive controls with ova of Diphyllobothrium latum/D. nihonkaiense, ova of Clonorchis sinensis and cysts of Giardia lamblia were used in this study. Both methods showed comparable correct identification rate (87.2% for the Para Tube vs. 86.3% for the conventional method).When five samples were examined at once, the Para Tube method reduced the procedure time compared with the conventional method (19 min 58 sec vs. 23 min 18 sec, P=0.0286). We concluded that the modified formalin-ether concentration method using the Para Tube is a rapid, simple, and reliable fecal concentration method for clinical use.
Clonorchis sinensis ; Diagnosis ; Diphyllobothrium ; Giardia lamblia ; Ovum ; Parasites

Giardia lamblia, a gastrointestinal protozoan, is one of the most common disease-causing parasites in the world. Giardiasis is primarily encountered in areas with poor sanitation, but it is also seen in more developed countries. A possible sequela of Giardia infections of the bowel is reactive arthritis or synovitis. Few reports of synovitis secondary to giardiasis exist in the literature. Arthropathy secondary to giardiasis is uncommon, but may be underdiagnosed. We present a 23 year-old woman who had polyarthritis after Giardia lamblia infestation. The synovitis subsided with treatment of the giardiasis with metronidazole. The diagnosis of Giardia synovitis should be suspected by the presence of Giardia cysts in the stool. Although uncommon, giardiasis can cause severe synovitis that may be confused with a septic joint.
Arthritis* ; Arthritis, Reactive ; Developed Countries ; Diagnosis ; Female ; Giardia lamblia ; Giardia* ; Giardiasis ; Humans ; Joints ; Metronidazole ; Parasites ; Sanitation ; Synovitis ; Young Adult*

Cryptosporidium parvum and Giardia duodenalis are the main diarrhea-causing parasitic pathogens; however, their prevalence in Korea is unknown. Here, we conducted a survey to determine the prevalence and genotype distribution of these 2 pathogens causing acute diarrhea in 8,571 patients hospitalized in 17 Regional Institute of Health Environment sites in Korea, during 2013–2016. C. parvum and G. duodenalis were detected and genotyped by nested PCR, and the isolate were molecularly characterized by sequencing the glycoprotein 60 (Gp60) and β-giardin genes, respectively. The overall prevalence of C. parvum and G. duodenalis was 0.37% (n=32) and 0.55% (n=47), respectively, and both pathogens were more prevalent in children under 9 years old. Molecular epidemiological analysis showed that the C. parvum isolates belonged to the IIa family and were subtyped as IIaA13G2R1, IIaA14G2R1, IIaA15G2R1, and IIaA18G3R1. Analysis of the β-giardin gene fragment from G. duodenalis showed that all positive strains belong to assemblage A. This is the first report on the molecular epidemiology and subtyping of C. parvum and G. duodenalis in such a large number of diarrheal patients in Korea. These results highlight the need for continuous monitoring of these zoonotic pathogens and provide a basis for implementing control and prevention strategies. Further, the results might be useful for epidemiological investigation of the source of outbreak.
Child ; Cryptosporidium parvum ; Cryptosporidium ; Diarrhea ; Genotype ; Giardia lamblia ; Giardia ; Glycoproteins ; Humans ; Korea ; Molecular Epidemiology ; Polymerase Chain Reaction ; Prevalence

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area.
Child ; Cross-Sectional Studies ; Diarrhea ; Education ; Endolimax ; Entamoeba ; Entamoeba histolytica ; Giardia ; Giardia lamblia ; Hand Disinfection ; Humans ; Iodine ; Male ; Myanmar* ; Prevalence* ; Sanitation ; Water Purification

Giardia lamblia is a protozoan that causes diarrheal diseases in humans. Cytoskeletal structures of Giardia trophozoites must be finely reorganized during cell division. To identify Giardia proteins which interact with microtubules (MTs), Giardia lysates were incubated with in vitro-polymerized MTs and then precipitated by ultracentifugation. A hypothetical protein (GL50803_8405) was identified in the precipitated fraction with polymerized MTs and was named GlMBP1 (G. lamblia microtubule-binding protein 1). Interaction of GlMBP1 with MTs was confirmed by MT binding assays using recombinant GlMBP1 (rGlMBP1). In vivo expression of GlMBP1 was shown by a real-time PCR and western blot analysis using anti-rGlMBP1 antibodies. Transgenic G. lamblia trophozoites were constructed by integrating a chimeric gene encoding hemagglutinin (HA)-tagged GlMBP1 into a Giardia chromosome. Immunofluorescence assays of this transgenic G. lamblia, using anti-HA antibodies, revealed that GlMBP1 mainly localized at the basal bodies, axonemes, and median bodies of G. lamblia trophozoites. This result indicates that GlMBP1 is a component of the G. lamblia cytoskeleton.
Antibodies ; Axoneme ; Basal Bodies ; Blotting, Western ; Cell Division ; Cytoskeleton ; Fluorescent Antibody Technique ; Giardia lamblia* ; Giardia* ; Hemagglutinins ; Humans ; Microtubules ; Polymers ; Real-Time Polymerase Chain Reaction ; Trophozoites

BACKGROUND: Because of a lack of quality control (QC) materials, stool examination has not been standardised. This study examined intestinal parasites in diarrhea specimens to manufacture and evaluate the performance stability of QC materials for stool examination. METHODS: This study examined diarrhea specimens submitted for stool culture. Microscopic examination was performed using the direct smear and formalin-ether concentration method (Military General Laboratory, MGL). Enzyme-linked immunosorbent assay (ELISA) kits (R-Biopharm AG, Germany) and xTAG Gastrointestinal Pathogen Panel (Luminex Corp., USA) were used for the three major protozoa: Cryptosporidium parvum, Giardia lamblia, and Entamoeba histolytica. Polymerase chain reaction (PCR) was performed for Dientamoeba fragilis and Blastocystis hominis. The QC materials for stool examination were generated using Diphyllobothrium nihonkaiense ova. The manufactured QC materials were evaluated under different storage conditions, with varying preservatives, temperatures, and storage times. RESULTS: From November 2015 to April 2016, 82 diarrhea specimens were collected and tested. All results from microscopy and ELISA were negative; C. parvum (n=2) and G. lamblia (n=1) were detected by xTAG, while D. fragilis (n=10) and B. hominis (n=2) were detected by PCR. High- and low-concentration QC materials were manufactured. Using the high-concentration QC material, ova were observed in all storage conditions using MGL. Using the low-concentration QC material, the ova were observed until 14 days, but not after 3 weeks. CONCLUSIONS: It should be considered for making QC materials for stool examinations that focus on D. fragilis and B. hominis frequently found in Korea and with the caution to the low-concentration of QC materials could be unstable.
Blastocystis hominis ; Cryptosporidium parvum ; Diarrhea* ; Dientamoeba ; Diphyllobothrium ; Entamoeba histolytica ; Enzyme-Linked Immunosorbent Assay ; Giardia ; Giardia lamblia ; Korea ; Methods* ; Microscopy ; Ovum ; Parasites* ; Polymerase Chain Reaction ; Quality Control*

This study aimed to develop a multiplex-touchdown PCR method to simultaneously detect 3 species of protozoan parasites, i.e., Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis, the major causes of traveler’s diarrhea and are resistant to standard antimicrobial treatments. The target genes included the Cryptosporidium oocyst wall protein for C. parvum, Glutamate dehydrogenase for G. lamblia, and 18S ribosomal RNA (18S rRNA) for C. cayetanensis. The sizes of the amplified fragments were 555, 188, and 400 bps, respectively. The multiplex-touchdown PCR protocol using a primer mixture simultaneously detected protozoa in human stools, and the amplified gene was detected in >1×10³ oocysts for C. parvum, >1×10⁴ cysts for G. lamblia, and >1 copy of the 18S rRNA gene for C. cayetanensis. Taken together, our protocol convincingly demonstrated the ability to simultaneously detect C. parvum, G. lamblia, and C. cayetanenesis in stool samples.
Cryptosporidium parvum* ; Cryptosporidium* ; Cyclospora* ; Diarrhea* ; Genes, rRNA ; Giardia lamblia* ; Giardia* ; Glutamate Dehydrogenase ; Humans ; Methods ; Multiplex Polymerase Chain Reaction ; Oocysts ; Parasites ; Polymerase Chain Reaction* ; RNA, Ribosomal, 18S

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