Cryptosporidium, a coccidian parasite first described by Tyzzer (1907) from a laboratory mouse, has become an important human enteric pathogen causing overwhelming diarrhea especially in immunocompromised patients such as AIDS. This parasite has been reported from over 20 countries and is recognized as a cosmopolitan species. In Korea, however, there has been no report on human as well as animal cryptosporidiosis. This study was performed so as to verify the presence of Cryptosporidium in Korea by activating the parasite from laboratory mice by immunosuppression. Total 65 conventionally-bred ICR mice including a control (5 mice) and 3 experimental groups (20 each) were used for this study. Group I was immunosuppressed with prednisolone injection (1 mg IM, every other day) for 7 weeks. Group II (prednisolone injection and tetracycline administration) and Group III (prednisolone injection and trimethoprim-sulfamethoxazole administration) were prepared to observe the effect of antibacterial agents on the activation of cryptosporidiosis. In fecal examinations of mice Cryptosporidium oocysts (4-6 microns in size) were detected from 1 week after the start of immunosuppression and the mice began to die. In H-E stained tissue sections of the lower jejunum, numerous very small (2-4 microns), dense, ovoid or spherical, slightly basophilic bodies were seen attached on the free border of mucosal epithelial cells. In scanning and transmission electron microscopic observations, these organisms were identified as various developmental stages of Cryptosporidium. The species is considered to be C. parvum.(ABSTRACT TRUNCATED AT 250 WORDS)
Cryptosporidiosis-etiology ; Cryptosporidiosis-immunology ; Cryptosporidium-growth-and-development ; English-Abstract ; Immune-Tolerance ; Intestinal-Diseases,-Parasitic-etiology ; Intestinal-Diseases,-Parasitic-immunology ; Mice- ; Mice,-Inbred-ICR ; *Cryptosporidiosis-parasitology ; *Cryptosporidium-pathogenicity ; *Immunosuppression- ; *Intestinal-Diseases,-Parasitic-parasitology

We investigated the response to challenge infection with Cryptosporidium parvum oocysts in immunosuppressed C57BL/6N mice. In the primary infection, fecal oocyst shedding and parasite colonization were greater in immunosuppressed mice than in nonimmunosuppressed mice. Compared with primary infection, challenge infection with C. parvum didn't show any oocyst shedding and parasite colonization. Especially, oocyst shedding and parasite colonization from the mice infected with heatkilled oocysts were not detected. After challenge infection with C. parvum oocysts, however, these mice were shedding small numbers of oocysts and parasite colonization. Except normal control and uninfected groups, the antibody titers of other groups appear similar. Based on the fecal oocyst shedding, parasite colonization of ilea, and antibody titers in the mice, these results suggest that the resistance to challenge infection with C. parvum in immunosuppressed C57BL/6N mice has increased.
Animals ; Antibodies, Protozoan/blood ; Cryptosporidiosis/*immunology/*parasitology ; Cryptosporidium parvum/*immunology ; Dexamethasone/immunology ; Enzyme-Linked Immunosorbent Assay ; Feces/parasitology ; Female ; Fluorescent Antibody Technique, Indirect ; Histocytochemistry ; Ileum/parasitology ; Immunocompromised Host ; Mice ; Mice, Inbred C57BL ; Oocysts/immunology ; Random Allocation

The seroprevalence of cryptosporidiosis was examined using patients' sera collected from hospitals located in 4 different areas of the Republic of Korea. ELISA was used to measure antibody titers against Cryptosporidium parvum antigens from a total of 2,394 serum samples, which were collected randomly from patients in local hospitals; 1) Chungbuk National University Hospital, 2) Konkuk University Hospital, 3) local hospitals in Chuncheon, Gangwon-do (province), 4) Jeonnam National University Hospital, from 2002 through 2003. Of the 2,394 samples assayed, 34%, 26%, and 56% were positive for C. parvum-specific IgG, IgM, and IgA antibodies, respectively. Positive IgG titers were most common in sera from Jeonnam National University Hospital, Gwangju, Jeollanam-do, and positive IgM titers were most common in sera from Chungbuk National University Hospital, Cheongju, Chuncheongbuk-do. The seropositivity was positively correlated with age for both the IgG and IgA antibodies but was negatively correlated with age for the IgM antibodies. Western blotting revealed that 92%, 83%, and 77% of sera positive for IgG, IgM, and IgA ELISA reacted with 27-kDa antigens, respectively. These results suggested that infection with Cryptosporidium in hospital patients occurs more commonly than previously reported in the Republic of Korea.
Adolescent ; Adult ; Aged ; Animals ; Antibodies, Protozoan/blood ; Child ; Child, Preschool ; Cross Infection/blood/*epidemiology/immunology/parasitology ; Cryptosporidiosis/blood/*epidemiology/immunology/parasitology ; Cryptosporidium parvum/*immunology ; Female ; Humans ; Infant ; Korea/epidemiology ; Male ; Middle Aged ; Young Adult

The seroprevalence of cryptosporidiosis was examined using patients' sera collected from hospitals located in 4 different areas of the Republic of Korea. ELISA was used to measure antibody titers against Cryptosporidium parvum antigens from a total of 2,394 serum samples, which were collected randomly from patients in local hospitals; 1) Chungbuk National University Hospital, 2) Konkuk University Hospital, 3) local hospitals in Chuncheon, Gangwon-do (province), 4) Jeonnam National University Hospital, from 2002 through 2003. Of the 2,394 samples assayed, 34%, 26%, and 56% were positive for C. parvum-specific IgG, IgM, and IgA antibodies, respectively. Positive IgG titers were most common in sera from Jeonnam National University Hospital, Gwangju, Jeollanam-do, and positive IgM titers were most common in sera from Chungbuk National University Hospital, Cheongju, Chuncheongbuk-do. The seropositivity was positively correlated with age for both the IgG and IgA antibodies but was negatively correlated with age for the IgM antibodies. Western blotting revealed that 92%, 83%, and 77% of sera positive for IgG, IgM, and IgA ELISA reacted with 27-kDa antigens, respectively. These results suggested that infection with Cryptosporidium in hospital patients occurs more commonly than previously reported in the Republic of Korea.
Adolescent ; Adult ; Aged ; Animals ; Antibodies, Protozoan/blood ; Child ; Child, Preschool ; Cross Infection/blood/*epidemiology/immunology/parasitology ; Cryptosporidiosis/blood/*epidemiology/immunology/parasitology ; Cryptosporidium parvum/*immunology ; Female ; Humans ; Infant ; Korea/epidemiology ; Male ; Middle Aged ; Young Adult

The diagnosis of cryptosporidiosis has been carried out using coprologic techniques in the Republic of Korea. However, antibody responses to Cryptosporidium have rarely been studied. Serum antibodies from HIV-positive/oocyst-positive Korean patients recognized significantly 31 and 27 kDa antigens, and HIV-negative/oocyst-positive individuals clearly reacted to 15/17 kDa antigens. Compared with oocyst-positive cases, 18.7% and 75.8% of sera from HIV-positive patients reacted to 31 and 27 kDa antigens. Only 11.1% of HIV-negative individuals reacted to 15/17 kDa. Based on these findings, serum antibody responses were different between HIV-positive and HIV-negative individuals infected with Cryptosporidium, and it is suggested that HIV-positive patients are more frequently exposed to C. parvum compared to HIV-negative individuals.
AIDS-Related Opportunistic Infections/blood/*immunology ; Adult ; Aged ; Animals ; Antibodies, Protozoan/*blood/immunology ; *Antibody Formation ; Antigens, Protozoan/chemistry/*immunology ; Blotting, Western/methods ; Cryptosporidiosis/blood/*immunology ; Feces/parasitology ; Female ; Humans ; Korea ; Male ; Middle Aged ; Protozoan Proteins/chemistry/immunology

Cryptosporidium parvum oocysts were isolated from a child suffering from acute gastroenteritis and successfully passaged in a calf and mice (designated hereafter SNU-H1) in the Republic of Korea; its molecular genotype has been analyzed. The GAG microsatellite region was amplified by a polymerase chain reaction (PCR), with a 238 base pair product, which is commonly displayed in C. parvum. The isolate was shown to be a mixture of the genotypes 1 (anthroponotic) and 2 (zoonotic). To study its infectivity in animals, 2 calves and 3 strains of mice were infected with the SNU-H1; in these animals, the propagation of both genotypes was successful. In immunosuppressed (ImSP) BALB/c and C57BL/6 mice the number of oocysts decreased after day 10 post-infection (PI) ; but in ImSP ICR mice, they remained constant until day 27 PI. The results show that both the C. parvum genotypes 1 and 2 can be propagated in calves and ImSP mice.
Animals ; Cattle ; Child ; Cryptosporidiosis/microbiology ; Cryptosporidium parvum/*genetics/immunology ; Diarrhea/parasitology ; Feces/parasitology ; Genotype ; Human ; Korea ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Inbred ICR ; Oocysts ; Polymerase Chain Reaction ; Support, Non-U.S. Gov't ; Zoonoses/parasitology

In order to determine the role of Peyer's patch lymphocytes (PPL) in self-clearing of Cryptosporidium parvum infection in murine models, changes in PPL subsets, their cytokine expression, and in vitro IgG1 and IgA secretions by PPL were observed in primary- and challenge-infected C57BL/6 mice. In primary-infected mice, the percentages of CD4+ T cells, CD8+ T cells, sIgA+ B cells, IL-2+ T cells, and IFN-gamma+ T cells among the PPL, increased significantly (P < 0.05) on day 10 post-infection (PI). Secretion of IgG1 and IgA in vitro by PPL also increased on day 10 PI. However, all these responses, with the exception of IgG1 and IgA secretions, decreased in challenge-infected mice on day 7 post-challenge (= day 13 PI); their IgG1 and IgA levels were higher (P > 0.05) than those in primaryinfected mice. The results suggest that murine PPL play an important role in self-clearing of primary C. parvum infections through proliferation of CD4+, CD8+, IL-2+, and IFN-gamma+ T cells, and IgG1 and IgA-secreting B cells. In challenge infections, the role of T cells is reduced whereas that of B cells secreting IgA appeared to be continuously important.
Animals ; Antibodies, Protozoan/analysis/metabolism ; Cattle ; Cryptosporidiosis/*immunology/parasitology ; Cryptosporidium parvum/*immunology ; Feces/parasitology ; Female ; Humans ; Immunoglobulin A/analysis/biosynthesis ; Immunoglobulin G/analysis/biosynthesis ; Interferon-gamma/analysis/biosynthesis ; Interleukin-2/analysis/biosynthesis ; Lymphocytes/*immunology ; Male ; Mice ; Mice, Inbred C57BL ; Peyer's Patches/cytology/*immunology ; Specific Pathogen-Free Organisms

The present study investigated the prevalence rate of Cryptosporidium parvum as a cause of diarrhea. We examined 942 stools of unidentified reasons occurring in patients in whom no immunosuppression had been detected. We examined the stools for Cryptosporidium parvum via modified acid-fast staining. The clinical records of all of the positive patients were then analyzed. Nine (1%) of the stools among the 942 diarrheal patients were positive for C. parvum. The positive rate in the males was 1.1% (6/522) and the positive rate of the females was 0.7% (3/420). Age distribution revealed that the highest positive rates were in patients in their sixties, with a positive rate of 2.5% (4/158). In the clinical tests, levels of c-reactive protein, erythrocyte sedimentation rates, and neutrophil proportions were normally increased in the peripheral blood, whereas the lymphocyte proportion exhibited a tendency towards decrease. The pathological findings were compatible with an inflammatory reaction in the host.
Adult ; Aged ; Animals ; Child, Preschool ; Cryptosporidiosis/*epidemiology/immunology ; *Cryptosporidium/isolation & purification ; Cryptosporidium parvum/isolation & purification ; Diarrhea/*epidemiology/immunology/parasitology ; Feces/parasitology ; Female ; HIV Seronegativity ; Humans ; Immunocompetence ; Korea/epidemiology ; Lymphocyte Count ; Male ; Middle Aged ; Prevalence ; Research Support, Non-U.S. Gov't ; Staining and Labeling

We observed the time gap between oocyst shedding and antibody responses in mice (3-week-old C57BL/6J females) infected with Cryptosporidium parvum. Oocyst shedding was verified by modified acid-fast staining. The individually collected mouse sera were assessed for C. parvum IgM and IgG antibodies by enzyme-linked immunosorbent assay from 5 to 25 weeks after infection. The results showed that C. parvum oocysts were shed from day 5 to 51 post-infection (PI). The IgM antibody titers to C. parvum peaked at week 5 PI, whereas the IgG antibody titers achieved maximum levels at week 25 PI. The results revealed that IgM responses to C. parvum infection occurred during the early stage of infection and overlapped with the oocyst shedding period, whereas IgG responses occurred during the late stage and was not correlated with oocyst shedding. Hence, IgM antibody detection may prove helpful for the diagnosis of acute cryptosporidiosis, and IgG antibody detection may prove effective for the detection of past infection and endemicity.
Animals ; Antibodies, Protozoan/*biosynthesis/blood ; Cryptosporidiosis/*immunology ; Cryptosporidium parvum/*immunology/isolation & purification ; Enzyme-Linked Immunosorbent Assay ; Feces/parasitology ; Female ; Immunocompromised Host ; Immunoglobulin G/biosynthesis/blood ; Immunoglobulin M/biosynthesis/blood ; Mice ; Mice, Inbred C57BL ; Oocysts/immunology ; Specific Pathogen-Free Organisms ; Time Factors