Cryptosporidium causes diarrhea, commonly occurs in children under 5 years old. The disease condition ranges from severe to asymptomatic infection. This study involved 1,287 children under 5 years old without diarrhea and did not use antibiotics within 2 weeks previous. 412 stool samples were microscopied directly and enriched. No sample was found that containing Cryptosporidium parvum under directive microscopy. The enriched method found 3 samples containing Cryptosporidium parvum. Asymptomatic infection rate is 0.7%. This rate was compared with the incidence of Cryptosporidium parvum in other countries.
Bacterial Infections ; Cryptosporidium parvum

We investigate the resistance of Cryptosporidium (C.) parvum oocysts to commercial bleach treatment. The viability and infectivity of C. parvum oocysts suspended in 100, 50, 25, 12.5, 6.3 or 3.2% aqueous commercial bleach for 10, 30, 60, 120 or 180 min at room temperature were assessed by nucleic acid Syto-9 staining, histologic examination of ileum and infectivity to immunosuppressed neonatal C57BL/6N mice. Although the viability was decreased compared with normal oocysts, all oocysts in contact with serially diluted commercial bleach for 180 min were alive by nucleic acid dye Syto-9 staining. And, microscopic examination of ileum sections revealed developmental stages of C. parvum in all mice. The oocyst shedding patterns between mice infected with oocysts contacted with commercial bleach and normal control mice were not significantly different each other. Although commercial bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that it is not an effective disinfectant for C. parvum oocysts under practical conditions. Authors conclude that, therefore, it is undesirable to recommend commercial bleach as a disinfectant for C. parvum oocysts.
Animals ; Cryptosporidium ; Cryptosporidium parvum ; Ileum ; Mice ; Oocysts ; Organic Chemicals ; Sodium Hypochlorite

Actin and some actin binding proteins such as tropomyosin, -actinin and troponin T were localized by simultaneous double immunogold labeling in several developmental stages of Cryptosporidium parvum. All of the observed developmental stages have many particles of tropomyosin and actin around pellicle and cytoplasm. Tropomyosin was labeled much more than the actin when these two proteins were labeled simultaneously. And alpha-actinin was labeled mostly in the pellicle, but troponin T labeling was very rarely observed. From this study, it was suggested that tropomyosin seems to be one of the major proteins of C. parvum, so it must be playing important roles in C. parvum.
parasitology-protozoa ; actin ; tropomyosin ; alpha-actinin ; troponin T ; Cryptosporidium parvum

Horizontal gene transfer (HGT) is the movement of genetic material between kingdoms and is considered to play a positive role in adaptation. Cryptosporidium parvum is a parasitic protozoan that causes an infectious disease. Its genome sequencing reported 14 bacteria-like proteins in the nuclear genome. Among them, cgd2_1810, which has been annotated as CysQ, a sulfite synthesis pathway protein, is listed as one of the candidates of genes horizontally transferred from bacterial origin. In this report, we examined this issue using phylogenetic analysis. Our BLAST search showed that C. parvum CysQ protein had the highest similarity with that of proteobacteria. Analysis with NCBI's Conserved Domain Tree showed phylogenetic incongruence, in that C. parvum CysQ protein was located within a branch of proteobacteria in the cd01638 domain, a bacterial member of the inositol monophosphatase family. According to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, the sulfate assimilation pathway, where CysQ plays an important role, is well conserved in most eukaryotes as well as prokaryotes. However, the Apicomplexa, including C. parvum, largely lack orthologous genes of the pathway, suggesting its loss in those protozoan lineages. Therefore, we conclude that C. parvum regained cysQ from proteobacteria by HGT, although its functional role is elusive.
Apicomplexa ; Bacteria ; Communicable Diseases ; Cryptosporidium ; Cryptosporidium parvum ; Eukaryota ; Gene Transfer, Horizontal ; Genome ; Humans ; Inositol ; Phosphoric Monoester Hydrolases ; Proteins ; Proteobacteria

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

OBJECTIVETo simultaneously detect viable Cryptosporidium parvum oocysts and Giardia duodenalis cysts for the purpose of reducing time and cost spent.

METHODSA duplex reverse transcription polymerase chain reaction (RT-PCR) method was newly developed.

RESULTSUsing duplex RT-PCR method for the hsp70 gene, viable (oo)cyst concentrations of 10(1) and 10(3) (oo)cysts/100 microL could be detected for C. parvum and G duodenalis, respectively. However, after heat-shock stimulation the expression of hsp70 mRNAs was detectable at 10(0) and 10(1) (oo)cysts/100 microL concentrations of C. parvum and G duodenalis, respectively. Thus, the detection sensitivity was significantly increased when the viable (oo)cysts were exposed to heat shock.

CONCLUSIONThis study describes a new duplex RT-PCR method for hsp70 gene to detect the viable (oo)cysts of the C. parvum and G duodenalis with less time consumed and at a lower cost. This newly developed duplex RT-PCR method may be used to detect these parasites not only in aquatic environments but also in clinical samples.

Child ; Cryptosporidiosis ; complications ; Cryptosporidium parvum ; Cyclospora ; Cyclosporiasis ; complications ; Diarrhea ; complications ; Humans ; Hypoproteinemia ; complications ; Male

Protozoa of the genus Cryptosporidium are small coccidian parasite known to infect the mucosal epithelium of a variety of animals including human, causing fatal course in immunodeficient patients as well as self-limited illness in healthy individuals. Various life cycle stages including trophozoite, meront, merozoite, gametocyte and oocyst in infected mucosa are a diagnostic feature. Electron microscopy (EM) provides sufficient findings for genus and species identification of this parasitic organism. The authors presented scanning and transmission EM findings of Cryptosporidium parvum infection in two children: one with acute lymphoblastic leukemia and the other without any evidence of immune compromise.
Animals ; Child ; Cryptosporidium parvum ; Cryptosporidium* ; Epithelium ; Humans* ; Intestines* ; Life Cycle Stages ; Merozoites ; Microscopy, Electron ; Mucous Membrane ; Oocysts ; Parasites ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Trophozoites

Cryptosporidium and Cyclospora are well-known coccidian protozoa that can cause waterborne and foodborne diarrheal illnesses. There have been a few reports regarding contamination in different vegetables with Cryptosporidium, but no data are available regarding the sources of Cyclospora infections in Korea. In the present study, we collected 6 kinds of vegetables (perilla leaves, winter-grown cabbages, chives, sprouts, blueberries, and cherry tomatoes) from July 2014 to June 2015, and investigated contamination by these 2 protozoa using multiplex quantitative real-time PCR. Among 404 vegetables, Cryptosporidium and Cyclospora were detected in 31 (7.7%) and 5 (1.2%) samples, respectively. In addition, Cryptosporidium was isolated from all 6 kinds of vegetables, whereas Cyclospora was detected in 4 kinds of vegetables (except perilla leaves and chives). Cryptosporidium (17.8%) and Cyclospora (2.9%) had the highest detection rates in chives and winter-grown cabbages, respectively. Cryptosporidium was detected all year long; however, Cyclospora was detected only from October to January. In 2 samples (sprout and blueberry), both Cryptosporidium and Cyclospora were detected. Further investigations using TaqI restriction enzyme fragmentation and nested PCR confirmed Cryptosporidium parvum and Cyclospora cayetanensis, respectively. In conclusion, we detected C. cayetanensis in vegetables for the first time in Korea. This suggests that screening should be employed to prevent these protozoal infections in Korea.
Blueberry Plant ; Brassica ; Chive ; Cryptosporidium parvum ; Cryptosporidium* ; Cyclospora* ; Korea* ; Mass Screening ; Perilla ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Vegetables*

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