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Abstract
Cryptosporidium spp is a ubiquitous parasite that has long been recognized as a frequent cause of protozoal diarrhea in humans. While infections in immunocompetent hosts are usually self-limiting, immunocompromised individuals can develop severe, chronic, and life-threatening illness. Vaccine development or immunotherapy that prevents disease or reduces the severity of infection is a relevant option since efficacious drug treatments are lacking. In particular, children in developing countries might benefit the most from a vaccine since cryptosporidiosis in early childhood has been reported to be associated with subsequent impairment in growth, physical fitness, and intellectual capacity. In this review, immunotherapies that have been used clinically are described as well as experimental vaccines and their evaluation in vivo.
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Affiliation(s)
- Jan R Mead
- Atlanta Veterans Affairs Medical Center; Decatur, GA USA; Department of Pediatrics; Emory University; Atlanta, GA USA
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2
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Kasper LH, Buzoni-Gatel D. Some Opportunistic Parasitic Infections in AIDS: Candidiasis, Pneumocystosis, Cryptosporidiosis, Toxoplasmosis. ACTA ACUST UNITED AC 2011; 14:150-6. [PMID: 17040733 DOI: 10.1016/s0169-4758(97)01212-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Almost 80% of patients with AIDS die from infections other than human immunodeficiency virus (HIV). These infections usually occur late in the course of disease when CD4(+) T-cell count has fallen below 200 permm(3) cells per milliliter. Most of these infections are caused by organisms that do not normally afflict healthy individuals and are thus considered to be opportunistic. In this article, Lloyd Kasper and Dominique Buzoni-Gatel review the host-parasite interaction for four important pathogens: Candida albicans and Pneumocystis carinii (usually non-invasive pathogens), Cryptosporidium parvum (invades the cells but remains localized in the gut) and Toxoplasma gondii (penetrates through the gut to cause systemic infection). These organisms, which generally cause limited or even insignificant clinical evidence of infection in the normal host, were chosen because of their high prevalence in AIDS patients and because they exhibit different invasive abilities. The reason why individuals with AIDS are susceptible to this particular group of pathogens is uncertain.
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Affiliation(s)
- L H Kasper
- Departments of Medicine (Neurology) and Microbiology, Dartmouth Medical School, Hanover, NH 03756, USA
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3
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O'Hara SP, Chen XM. The cell biology of cryptosporidium infection. Microbes Infect 2011; 13:721-30. [PMID: 21458585 DOI: 10.1016/j.micinf.2011.03.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 03/23/2011] [Indexed: 01/13/2023]
Abstract
Cryptosporidiosis remains a significant cause of enteric disease worldwide. Basic investigations of host: pathogen interactions have revealed the intricate processes mediating infection. The following summarizes the interactions that mediate infection and the host responses that both permit and ultimately clear the infection.
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Affiliation(s)
- Steven P O'Hara
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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4
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Collinet-Adler S, Ward HD. Cryptosporidiosis: environmental, therapeutic, and preventive challenges. Eur J Clin Microbiol Infect Dis 2010; 29:927-35. [PMID: 20521158 PMCID: PMC4049176 DOI: 10.1007/s10096-010-0960-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 05/06/2010] [Indexed: 10/19/2022]
Abstract
Cryptosporidium spp. are responsible for endemic and epidemic disease worldwide. Clinical manifestations may include acute, persistent, or chronic diarrhea, biliary, and pulmonary disease. Disease severity ranges from asymptomatic or mild to severe, intractable diarrhea with wasting depending on immune status, nutrition, and age. Transmission is fecal-oral with both human and animal reservoirs. Disease is often self limited in healthy individuals, but therapy remains a challenge in the immune-compromised. Prevention currently depends on appropriate hygiene and proper water management and treatment.
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Affiliation(s)
- S Collinet-Adler
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, 800 Washington Street, Boston, MA 02111, USA.
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5
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Boulter-Bitzer JI, Lee H, Trevors JT. Single chain variable fragment antibodies selected by phage display against the sporozoite surface antigen S16 of Cryptosporidium parvum. Exp Parasitol 2010; 125:124-9. [DOI: 10.1016/j.exppara.2010.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Revised: 12/30/2009] [Accepted: 01/11/2010] [Indexed: 10/19/2022]
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6
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Yu Q, Li J, Zhang X, Gong P, Zhang G, Li S, Wang H. Induction of immune responses in mice by a DNA vaccine encoding Cryptosporidium parvum Cp12 and Cp21 and its effect against homologous oocyst challenge. Vet Parasitol 2010; 172:1-7. [PMID: 20541869 DOI: 10.1016/j.vetpar.2010.04.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 04/19/2010] [Accepted: 04/27/2010] [Indexed: 12/01/2022]
Abstract
Cp12 and Cp21 surface proteins on the sporozoite of Cryptosporidium parvum have been identified as the immunodominant antigens involved in the immune response to C. parvum infection. In the present study, the efficacy of Cp12 and Cp21 antigens as vaccine candidates was investigated in BALB/c mice that were susceptible to C. parvum infection. DNA sequences of Cp12, Cp21, Cp12-Cp21, and C (CpG oligodeoxynucleotide (ODN))-Cp12-Cp21 were amplified and then cloned into pVAX1 vector to form the four recombinant plasmids pVAX1-Cp12, pVAX1-Cp21, pVAX1-Cp12-Cp21, and pVAX1-C-Cp12-Cp21. Recombinant protein expression from these four plasmids in HeLa cells were confirmed by indirect immunofluorescence staining and Western blot analysis. The in vivo efficacies of the four DNA vaccines were tested in BALB/c mice. The results indicated that the four DNA vaccines elicited significant antibody responses and specific cellular responses when compared to control mice that received vector only or PBS. Among those four plasmids, pVAX1-C-Cp12-Cp21 elicited significantly higher levels of IgG. Also, the percentages of CD4(+) and CD8(+) T cells were significantly higher in the group with pVAX1-C-Cp12-Cp21 nasal sprays. Their efficacy in immunoprotection against homologous challenge was also detected after administration of the four DNA vaccines. The results showed that mice in the pVAX1-C-Cp12-Cp21 nasal group had a 77.5% reduction in the level of oocyst shedding and a significant difference was detected when this group was compared with the pVAX1, PBS, pVAX1-Cp12, and pVAX1-Cp21 groups. The reduction in the level of oocysts shedding from the group of pVAX1-C-Cp12-Cp21 nasal spray was also higher than that of pVAX1-Cp12-Cp21 group. These results suggested that C-Cp12-Cp21-DNA may provide an effective means of eliciting humoral and cellular responses and generating protective immunity against C. parvum infections in BALB/c mice.
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Affiliation(s)
- Qinlei Yu
- College of Animal Science and Veterinary Medicine, Jilin University, 5333 Xi'an Road, Changchun 130062, China
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7
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Thompson RCA, Olson ME, Zhu G, Enomoto S, Abrahamsen MS, Hijjawi NS. Cryptosporidium and cryptosporidiosis. ADVANCES IN PARASITOLOGY 2009; 59:77-158. [PMID: 16182865 DOI: 10.1016/s0065-308x(05)59002-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Cryptosporidium is one of the most common enteric protozoan parasites of vertebrates with a wide host range that includes humans and domestic animals. It is a significant cause of diarrhoeal disease and an ubiquitous contaminant of water which serves as an excellent vehicle for transmission. A better understanding of the development and life cycle of Cryptosporidium, and new insights into its phylogenetic relationships, have illustrated the need to re-evaluate many aspects of the biology of Cryptosporidium. This has been reinforced by information obtained from the recent successful Cryptosporidium genome sequencing project, which has emphasised the uniqueness of this organism in terms of its parasite life style and evolutionary biology. This chapter provides an up to date review of the biology, biochemistry and host parasite relationships of Cryptosporidium.
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Affiliation(s)
- R C A Thompson
- Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, WA 6150, Australia.
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8
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Abstract
Immunoglobulins (Igs), also called antibodies, are present in milk and colostrum of all lactating species. Igs are divided into classes having different physico-chemical structures and biological activities. The major Ig classes in bovine and human milk are IgA, IgG and IgM. Bovine colostral Igs provide the newborn calf with passive immune protection against microbial infections until the calf’s own immune system matures. Colostral Ig preparations designed for farm animals have been commercially available for many years. Potential health benefits attributed to bovine colostrum have increased manufacture and marketing of colostral Ig-based dietary supplements also for human use. Furthermore, specific anti-microbial antibodies can be produced into colostrum by immunizing cows with vaccines made of pathogenic microorganisms. These antibodies can be concentrated and used to formulate so-called immune milk preparations. Such preparations have proven effective in prevention of animal and human infections caused, e.g. by rotavirus, Shigella flexneri, Escherichia coli, Clostridium difficile, Streptococcus mutans, Cryptosporidium parvum and Helicobacter pylori. Their therapeutic efficacy, however, seems limited. A few immune milk products have been commercialized and more can be expected in the future for use, e.g. as a supportive means in antibiotic treatments and for prevention of hospital infections.
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9
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Pokorny NJ, Boulter-Bitzer JI, Hall JC, Trevors JT, Lee H. Inhibition of Cryptosporidium parvum infection of a mammalian cell culture by recombinant scFv antibodies. Antonie van Leeuwenhoek 2008; 94:353-64. [PMID: 18581250 DOI: 10.1007/s10482-008-9252-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Accepted: 05/12/2008] [Indexed: 11/28/2022]
Abstract
Two phage display antibody libraries (Tomlinson I and J) were screened against the whole oocysts of Cryptosporidium parvum to select for scFv (single chain variable fragment) antibodies. Three scFv antibodies were selected that bound to C. parvum oocysts as determined by monoclonal phage ELISA. DNA sequencing revealed that clone A11 lacked the majority of its V (H) chain. Clone B10 had a stop codon in the first framework region of the V (H) chain. We changed this stop codon to Gly by site-directed mutagenesis, and designated the variant mutB10. Clone B9 had a complete scFv gene with no internal stop codons. These antibody genes were individually subcloned into the pET-20b expression vector for soluble scFv antibody production. C. parvum infectivity was determined by infection of HCT-8 tissue culture monolayers and quantified by the foci detection method. By incubating C. parvum oocysts with individual scFv antibodies for 1 h at 37 degrees C prior to infecting the HCT-8 cells with the oocyst-scFv mixture, the infectivity of C. parvum was reduced in a dose-dependent manner. At the highest soluble scFv concentration tested (4 nmol), the mean number of infectious foci was reduced by 82%, 73% and 94% for the A11, B9 and mutB10 scFv, respectively. This inhibition of oocyst infectivity was abolished when the scFvs were exposed to boiling water. The results showed that the 3 selected scFvs bound to C. parvum oocysts, and their ability to neutralize infectivity may have potential therapeutic potential against cryptosporidiosis.
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Affiliation(s)
- Nicholas J Pokorny
- Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada
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Yao L, Yin J, Zhang X, Liu Q, Li J, Chen L, Zhao Y, Gong P, Liu C. Cryptosporidium parvum: Identification of a new surface adhesion protein on sporozoite and oocyst by screening of a phage-display cDNA library. Exp Parasitol 2007; 115:333-8. [PMID: 17097085 DOI: 10.1016/j.exppara.2006.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 09/13/2006] [Accepted: 09/21/2006] [Indexed: 10/23/2022]
Abstract
Cryptosporidium parvum is a significant cause of diarrheal disease worldwide. The specific molecules that mediate C. parvum-host interaction and the molecular mechanisms involved in the pathogenesis are unknown. In this study we described a novel phage display method to identify surface adhesion proteins of C. parvum. A cDNA library of the sporozoite and oocyst stages of C. parvum expressed on the surface of T7 phage was screened with intestinal epithelial cells (IECs) from the newborn Cryptosporidium-free Holstein calves. Proteins that selectively and specifically bound to IECs were then enriched using a multi-step panning procedure. Two proteins of C. parvum were selected, one was previously reported (p23), which was an important surface adhesion protein; the other was a novel surface adherence protein (CP12). Sequence analysis showed that CP12 has a N-terminal signal peptide, a transmembrane region, a N-glycosylation site, a casein kinase II phosphorylation site and two N-myristoylation sites. Immunofluorescence assay (IFA) using antibody specific for rCP12 demonstrated that the antibody can specifically bind the surface of sporozoite and oocyst, especially apical region of sporozoite. The surface localization of CP12 and its involvement in the host-parasite interaction suggest that it may serve as an effective target for specific preventive and therapeutic measures for cryptosporidiosis.
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Affiliation(s)
- Longquan Yao
- College of Animal Science and Veterinary Medicine, Jilin University, Changchun, PR China
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11
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Boulter-Bitzer JI, Lee H, Trevors JT. Molecular targets for detection and immunotherapy in Cryptosporidium parvum. Biotechnol Adv 2006; 25:13-44. [PMID: 17055210 DOI: 10.1016/j.biotechadv.2006.08.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 08/14/2006] [Accepted: 08/22/2006] [Indexed: 11/21/2022]
Abstract
Cryptosporidium parvum is an obligate protozoan parasite responsible for the diarrheal illness cryptosporidiosis in humans and animals. Although C. parvum is particularly pathogenic in immunocompromised hosts, the molecular mechanisms by which C. parvum invades the host epithelial cells are not well understood. Characterization of molecular-based antigenic targets of C. parvum is required to improve the specificity of detection, viability assessments, and immunotherapy (treatment). A number of zoite surface (glyco)proteins are known to be expressed during, and believed to be involved in, invasion and infection of host epithelial cells. In the absence of protective treatments for this illness, antibodies targeted against these zoite surface (glyco)proteins offers a rational approach to therapy. Monoclonal, polyclonal and recombinant antibodies represent useful immunotherapeutic means of combating infection, especially when highly immunogenic C. parvum antigens are utilized as targets. Interruption of life cycle stages of this parasite via antibodies that target critical surface-exposed proteins can potentially decrease the severity of disease symptoms and subsequent re-infection of host tissues. In addition, development of vaccines to this parasite based on the same antigens may be a valuable means of preventing infection. This paper describes many of the zoite surface glycoproteins potentially involved in infection, as well as summarizes many of the immunotherapeutic studies completed to date. The identification and characterization of antibodies that bind to C. parvum-specific cell surface antigens of the oocyst and sporozoite will allow researchers to fully realize the potential of molecular-based immunotherapy to this parasite.
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Martín-Gómez S, Alvarez-Sánchez MA, Rojo-Vázquez FA. Obtaining hyperimmune anti-Cryptosporidium parvum ovine colostrum. A study of the humoral immune response in immunized sheep. Parasitol Res 2005; 98:119-29. [PMID: 16292678 DOI: 10.1007/s00436-005-0031-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 09/20/2005] [Indexed: 10/25/2022]
Abstract
Three ewes were immunized five times over a 2-month period prior to giving birth by intramuscular injection, oral administration and intramammary infusion of antigen and viable or freeze-dried Cryptosporidium parvum oocyst solution emulsified with Freund's complete and incomplete adjuvant. Two animals served as controls and another two as adjuvant controls. Serum was collected at first immunization and thereafter every 2 to 4 weeks. Colostrum and milk were collected as well. All samples were assayed for C. parvum-specific antibodies using an enzyme-linked immunosorbent assay methodology, and Western blotting was used to recognize the C. parvum antigens. Hyperimmunization resulted in a progressive and significant increase in specific anti-C. parvum serum IgG, IgA and IgM titres, with the highest values noted at the point of lambing. Titres decreased slightly in milk, although they were in all cases higher than those in the control animals. Moreover, some 30 bands of C. parvum were recognized.
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Affiliation(s)
- S Martín-Gómez
- Departamento de Patología Animal (Sanidad Animal), Facultad de Veterinaria, Universidad de León, C/ Profesor Pedro Cármenes s/n, 24071 León, Spain
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13
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Martín-Gómez S, Alvarez-Sánchez MA, Rojo-Vázquez FA. ORAL ADMINISTRATION OF HYPERIMMUNE ANTI–CRYPTOSPORIDIUM PARVUM OVINE COLOSTRAL WHEY CONFERS A HIGH LEVEL OF PROTECTION AGAINST CRYPTOSPORIDIOSIS IN NEWBORN NMRI MICE. J Parasitol 2005; 91:674-8. [PMID: 16108564 DOI: 10.1645/ge-3423] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Hyperimmune anti-Cryptosporidium parvum ovine colostral whey (HOCW) was tested to determine whether it conferred passive immunity to newborn NMRI mice. Three HOCWs (groups IV-VI), 2 nonimmune colostral wheys (groups II and III), and PBS (group I) were administered once (experiment A) and 3 times (experiment B) daily from -1 to 15 days postinfection (PI). Mice in groups I-VI were inoculated with 5 x 10(5) oocysts (day 0 PI), and group VII mice acted as controls. The percentage and intensity of infection were measured at 6, 9, 12, and 16 days PI. In experiment A, HOCW did not reduce significantly the percentage and intensity of infection except for mice in group VI treated with HOCW with the highest titers of anti-C. parvum antibodies. In contrast, no infection was detected in between 18.7 and 62.5% of the mice in groups IV-VI in experiment B. Furthermore, in these groups, the intensity of the infection decreased significantly, ranging from 83.5 to 97.4%. Thus, HOCW did not completely avoid infection, but a high level of protection was observed, being proportional to the titer of specific antibodies and the amount of whey administered orally. Finally, group VII showed no presence of oocysts.
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Affiliation(s)
- S Martín-Gómez
- Department of Sanidad Animal, Faculty of Veterinary, University of León, C/Profesor Pedro Cármenes s/n, 24071 León, Spain
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Sood S, Rishi P, Dhawan V, Sharma S, Ganguly NK. Protection mediated by antibodies to iron-regulated outer-membrane proteins of S. typhi in a mouse peritonitis model. Mol Cell Biochem 2005; 273:69-78. [PMID: 16013441 DOI: 10.1007/s11010-005-7756-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Iron limitation induces the expression of iron-regulated outer-membrane proteins, which are not expressed under iron sufficient growth conditions. In the present study, these proteins were purified in order to evaluate their protective potential in the experimental model. Anti IROMPs antiserum was raised in rabbits. In mice, passively transferred anti-IROMPs antibodies provided 60% protection against the serovar Typhi challenge dose (9.6 LD50). The hyperimmune serum containing anti-IROMPs antibodies were also found to be bactericidal in the presence of complement whereas no bacterial killing was observed with pre-immunized serum. Bactericidal titre of anti-IROMPs serum was fond to be 2000 as more than 50% killing was observed with serum diluted to 1:2000. The role of IROMPs was assessed in actively-immunized mice followed by challenge with serovar Typhi. These proteins provided protection in 90% mice against challenge (480 LD50) with the pathogen. The levels of isotypes of antibodies (IgG, IgM & IgA) in the sera and secretory antibodies (sIgA) in the gut fluid of immunized mice correlated with the protection. This study, thus indicates that anti IROMPs antibodies may play an important role in providing protection at systemic as well as at mucosal level.
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Affiliation(s)
- Shaloo Sood
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Martín-Gómez S, Alvarez-Sánchez MA, Rojo-Vázquez FA. Immunization protocols against Cryptosporidium parvum in ovines: protection in suckling lambs. Vet Parasitol 2005; 129:11-20. [PMID: 15817197 DOI: 10.1016/j.vetpar.2004.11.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 11/15/2004] [Accepted: 11/26/2004] [Indexed: 10/25/2022]
Abstract
Ovine colostrum and milk from immunized ewes were tested for their ability to prevent cryptosporidiosis in the lambs experimentally infected with 10(6) oocysts of Cryptosporidium parvum at 36-48 h of age (day 0 post-infection). All lambs became infected and developed clinical cryptosporidiosis. However, lambs fed by immunized dams have shown shedding involved, significantly, fewer oocysts and lasted for a shorter period than in control lambs. In addition, diarrhoea was less severe. The best results emerged in lambs of ewes immunized by intramuscular injection of an emulsion of 2 ml of Freund's complete adjuvant and 2 ml of C. parvum antigen in sterile phosphate buffered saline solution, administrated four weeks before parturition, together with an intramammary infusion of 25 microg of antigen in 2 ml of sterile PBS emulsified in 2 ml of Freund's incomplete adjuvant, which showed the highest anti-C. parvum titres in lacteal secretions. In their case, the onset of output of oocysts was delayed by two days, the patent period was shortened by three days, their diarrhoea continued for only three days, and the quantity of oocysts shed decreased by 77%. The outcome was that at the end of the study they had a live weight gain of 2 kg more than the lambs in the control group. These results indicate that lactogenic immunoprophylaxis should help mitigate the financial losses caused by cryptosporidiosis in small ruminants, as well as reducing the risk of infection of humans through the decreased contamination of the environment with oocysts.
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Affiliation(s)
- S Martín-Gómez
- Dpt. Patología Animal (Sanidad Animal), Facultad de Veterinaria, Universidad de León, C/Profesor Pedro Cármenes s/n, 24071 León, Spain
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16
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Ramirez NE, Ward LA, Sreevatsan S. A review of the biology and epidemiology of cryptosporidiosis in humans and animals. Microbes Infect 2005; 6:773-85. [PMID: 15207825 DOI: 10.1016/j.micinf.2004.02.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The epidemiology of cryptosporidiosis, an infection caused by several genotypically and phenotypically diverse Cryptosporidium species, has been dynamically changing over the past decade from that of a rare, largely asymptomatic infection to an acute enteric disease of animals and humans. In this review, the current understanding of factors (biology and epidemiology) contributing to the emergence of cryptosporidiosis in animals, including parasite biology, genetic diversity, environmental spread, livestock production trends, presence of the parasite in livestock and companion animals, and potential risk of transmission from animals to humans is highlighted. Potential control measures and the role of veterinary and medical professionals in the prevention of cryptosporidiosis are also discussed.
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Affiliation(s)
- Norma E Ramirez
- Department of Veterinary Preventive Medicine, Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Veterinary Medicine, The Ohio State University, FAHRP Building, 1680 Madison Avenue, Wooster, OH 44691, USA
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17
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Abstract
The in vitro cultivation of protozoan parasites of the genus Cryptosporidium has advanced significantly in recent years. These obligate, intracellular parasites colonize the epithelium of the digestive and respiratory tracts, are often difficult to obtain in significant numbers, produce durable oocysts that defy conventional chemical disinfection methods, and are persistently infectious when stored at refrigerated temperatures (4 to 8 degrees C). While continuous culture and efficient life cycle completion (oocyst production) have not yet been achieved in vitro, routine methods for parasite preparation and cell culture infection and assays for parasite life cycle development have been established. Parasite yields may be limited, but in vitro growth is sufficient to support a variety of research studies, including assessing potential drug therapies, evaluating oocyst disinfection methods, and characterizing life cycle stage development and differentiation.
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Affiliation(s)
- Michael J Arrowood
- Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Public Health Service, U.S. Department of Health and Human Services, Atlanta, Georgia 30341, USA.
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Teunis PFM, Chappell CL, Okhuysen PC. Cryptosporidium dose response studies: variation between isolates. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2002; 22:175-183. [PMID: 12017359 DOI: 10.1111/0272-4332.00014] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The infectivity of three different isolates of the waterborne protozoan parasite Cryptosporidium parvum has been tested in human feeding studies. These three isolates (Iowa, TAMU, and UCP) have different ID50s, indicating substantial variation in their infectivity for humans. This finding is of great importance for quantitative risk assessment as it provides strong evidence for heterogeneity in infectivity among isolates of the same species.
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Affiliation(s)
- Peter F M Teunis
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
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19
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Palmeira P, Carbonare SB, Silva ML, Trabulsi LR, Carneiro-Sampaio MM. Inhibition of enteropathogenic Escherichia coli (EPEC) adherence to HEp-2 cells by bovine colostrum and milk. Allergol Immunopathol (Madr) 2001; 29:229-37. [PMID: 11834181 DOI: 10.1016/s0301-0546(01)79064-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND enteropathogenic Escherichia coli (EPEC) is the main etiological agent of infantile diarrhea in Brazil and other developing countries. Human milk IgA protects newborn intestinal mucosa by inhibiting bacterial adhesion to epithelial cells and this effect is shown by in vitro assays of EPEC adhesion to HEp-2 cultured cells. Bovine milk, if effective in promoting this protection, could be an useful tool in the absence of the natural breastfeeding, in high-risk nurseries or in hospital infections. METHODS the effect of colostrum, milk, and serum from dairy cows on the adherence to EPEC to HEp-2 cells was investigated. Colostrum from immunized and control animals and industrialized milk formulas were fractionated through a membrane device with a molecular weight cut off 10 kDa. The high molecular weight fraction (HMWF) of bovine colostrum was depleted of IgG through an affinity column and absorbed with an EPEC adherent strain. Antibodies were searched by ELISA and immunoblotting (IB). RESULTS colostrum and milk from EPEC-immunized animals showed and inhibitory activity on adherence similar to that of control non-immunized animals. The inhibitory effect on adhesion was related to the HMWF. IgG-depleted colostrum partially retained the inhibitory effect, whereas IgG-rich eluate lost this property. The EPEC-absorbed fraction retained the inhibitory property. Industrialized milk formulas and respective HMWF also inhibited bacterial adherence. In IB assays, colostrum and milk samples from immunized animals recognized proteins of 30-40 kDa and 94 kDa, a molecular weight consistent with the adhesin intimin, in EPEC extracts. CONCLUSIONS the inhibitory effect of EPEC adherence may be mediated by HMWF components, and IgG was not the only component responsible for this phenomenon.
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Affiliation(s)
- P Palmeira
- Department of Immunology, Instituto de Cincias Biomédicas, Universidade de So Paulo, So Paulo, Brazil
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20
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Cevallos AM, Bhat N, Verdon R, Hamer DH, Stein B, Tzipori S, Pereira ME, Keusch GT, Ward HD. Mediation of Cryptosporidium parvum infection in vitro by mucin-like glycoproteins defined by a neutralizing monoclonal antibody. Infect Immun 2000; 68:5167-75. [PMID: 10948140 PMCID: PMC101770 DOI: 10.1128/iai.68.9.5167-5175.2000] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The protozoan parasite Cryptosporidium parvum is a significant cause of diarrheal disease worldwide. Attachment to and invasion of host intestinal epithelial cells by C. parvum sporozoites are crucial steps in the pathogenesis of cryptosporidiosis. The molecular basis of these initial interactions is unknown. In order to identify putative C. parvum adhesion- and invasion-specific proteins, we raised monoclonal antibodies (MAbs) to sporozoites and evaluated them for inhibition of attachment and invasion in vitro. Using this approach, we identified two glycoproteins recognized by 4E9, a MAb which neutralized C. parvum infection and inhibited sporozoite attachment to intestinal epithelial cells in vitro. 4E9 recognized a 40-kDa glycoprotein named gp40 and a second, >220-kDa protein which was identified as GP900, a previously described mucin-like glycoprotein. Glycoproteins recognized by 4E9 are localized to the surface and apical region of invasive stages and are shed in trails from the parasite during gliding motility. The epitope recognized by 4E9 contains alpha-N-acetylgalactosamine residues, which are present in a mucin-type O-glycosidic linkage. Lectins specific for these glycans bind to the surface and apical region of sporozoites and block attachment to host cells. The surface and apical localization of these glycoproteins and the neutralizing effect of the MAb and alpha-N-acetylgalactosamine-specific lectins strongly implicate these proteins and their glycotopes as playing a role in C. parvum-host cell interactions.
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Affiliation(s)
- A M Cevallos
- Division of Geographic Medicine and Infectious Diseases, Tupper Research Institute, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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21
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Strong WB, Gut J, Nelson RG. Cloning and sequence analysis of a highly polymorphic Cryptosporidium parvum gene encoding a 60-kilodalton glycoprotein and characterization of its 15- and 45-kilodalton zoite surface antigen products. Infect Immun 2000; 68:4117-34. [PMID: 10858229 PMCID: PMC101708 DOI: 10.1128/iai.68.7.4117-4134.2000] [Citation(s) in RCA: 265] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The apicomplexan parasite Cryptosporidium parvum is a major cause of serious diarrheal disease in both humans and animals. No efficacious chemo- or immunotherapies have been identified for cryptosporidiosis, but certain antibodies directed against zoite surface antigens and/or proteins shed by gliding zoites have been shown to neutralize infectivity in vitro and/or to passively protect against, or ameliorate, disease in vivo. We previously used monoclonal antibody 11A5 to identify a 15-kDa surface glycoprotein that was shed behind motile sporozoites and was recognized by several lectins that neutralized parasite infectivity for cultured epithelial cells. Here we report the cloning and sequence analysis of the gene encoding this 11A5 antigen. Surprisingly, the gene encoded a 330-amino-acid, mucin-like glycoprotein that was predicted to contain an N-terminal signal peptide, a homopolymeric tract of serine residues, 36 sites of O-linked glycosylation, and a hydrophobic C-terminal peptide specifying attachment of a glycosylphosphatidylinositol anchor. The single-copy gene lacked introns and was expressed during merogony to produce a 60-kDa precursor which was proteolytically cleaved to 15- and 45-kDa glycoprotein products that both localized to the surface of sporozoites and merozoites. The gp15/45/60 gene displayed a very high degree of sequence diversity among C. parvum isolates, and the numerous single-nucleotide and single-amino-acid polymorphisms defined five to six allelic classes, each characterized by additional intra-allelic sequence variation. The gp15/45/60 single-nucleotide polymorphisms will prove useful for haplotyping and fingerprinting isolates and for establishing meaningful relationships between C. parvum genotype and phenotype.
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MESH Headings
- Alleles
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/metabolism
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Antigens, Surface/metabolism
- Base Sequence
- Cloning, Molecular
- Cryptosporidiosis/parasitology
- Cryptosporidium parvum/genetics
- Cryptosporidium parvum/immunology
- Cryptosporidium parvum/pathogenicity
- DNA Primers/genetics
- DNA, Protozoan/genetics
- Gene Expression Regulation, Developmental
- Genes, Protozoan
- Genotype
- Humans
- Molecular Sequence Data
- Molecular Weight
- Polymorphism, Genetic
- Protein Processing, Post-Translational
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Sequence Homology, Amino Acid
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Affiliation(s)
- W B Strong
- Division of Infectious Diseases, San Francisco General Hospital, University of California, San Francisco, San Francisco, California 94143-0811, USA
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22
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Abstract
Cryptosporidium parvum is an important zoonotic protozoan pathogen that causes acute infection and self-limiting gastrointestinal disease in neonatal calves. There are currently no consistently effective antimicrobials available to control cryptosporidiosis. Therefore, immunotherapeutic and vaccination protocols offer the greatest potential for long-term control of the disease. In order to devise effective control measures, it is important to better define mucosal immunity to C. parvum in young calves. This review summarizes the information that has accumulated over the last decade which helps to define the intestinal mucosal immune system in neonatal calves, and the events that occur in the intestinal mucosa after infection by C. parvum.
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Affiliation(s)
- C R Wyatt
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040, USA
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23
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Perryman LE, Kapil SJ, Jones ML, Hunt EL. Protection of calves against cryptosporidiosis with immune bovine colostrum induced by a Cryptosporidium parvum recombinant protein. Vaccine 1999; 17:2142-9. [PMID: 10367947 DOI: 10.1016/s0264-410x(98)00477-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of the study was to determine if immunization with a recombinant protein (rC7) of Cryptosporidium parvum would induce immune bovine colostrum that protected calves against cryptosporidiosis following oral challenge with C. parvum oocysts. Late gestation Holstein cows with low titers of antibody to the p23 antigen of C. parvum were immunized three times with 300 microg affinity purified rC7 C. parvum recombinant protein (immune cows), or left nonimmunized (control cows). Colostrum was obtained from each cow in both groups and partitioned into identical aliquots of pooled immune colostrum or pooled control colostrum. Twelve calves obtained at birth received either immune or control colostrum within the first 2 h, and again at 12 and 24 h of age. Each calf was challenged orally with 10(7) C. parvum oocysts at 12 h of age and monitored for signs of cryptosporidiosis. All six calves administered pooled control colostrum developed severe diarrhea (mean total fecal volume = 8447+/-5600 ml) and shed an average of 1.87+/-1.66 x 10(12) C. parvum oocysts. None of the six calves administered pooled immune colostrum developed diarrhea (mean total fecal volume = 740+/-750 ml, p < 0.05), and shed significantly fewer oocysts (3.05+/-2.26 x 10(9), p < 0.05). The absence of diarrhea and 2.79 log10 (99.8%) reduction in oocyst excretion indicates that immune bovine colostrum induced by immunization with C. parvum recombinant protein rC7 provided substantial protection against cryptosporidiosis in neonatal calves.
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Affiliation(s)
- L E Perryman
- Department of Microbiology, Pathology and Parasitology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
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24
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Rochelle PA, De Leon R, Johnson A, Stewart MH, Wolfe RL. Evaluation of immunomagnetic separation for recovery of infectious Cryptosporidium parvum oocysts from environmental samples. Appl Environ Microbiol 1999; 65:841-5. [PMID: 9925626 PMCID: PMC91105 DOI: 10.1128/aem.65.2.841-845.1999] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two commercial immunomagnetic separation (IMS) kits for Cryptosporidium were compared for recovery of oocysts from environmental samples. Oocyst recovery efficiencies with the Dynal and Crypto-Scan kits ranged from 62 to 100% and 34 to 74%, respectively, for seeded environmental water concentrates (turbidity of 210 to 11,480 nephelometric turbidity units). Recovery efficiencies were dependent on the mechanism of agitation during the magnetic capture procedure. An assay combining in vitro cell culture and reverse transcriptase PCR demonstrated that oocysts recovered by IMS retained their infectivity.
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Affiliation(s)
- P A Rochelle
- Water Quality Laboratory, Metropolitan Water District of Southern California, La Verne, California 91750-3399, USA.
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25
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Barnes DA, Bonnin A, Huang JX, Gousset L, Wu J, Gut J, Doyle P, Dubremetz JF, Ward H, Petersen C. A novel multi-domain mucin-like glycoprotein of Cryptosporidium parvum mediates invasion. Mol Biochem Parasitol 1998; 96:93-110. [PMID: 9851610 DOI: 10.1016/s0166-6851(98)00119-4] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cryptosporidium parvum is a protozoan parasite which produces self-limited disease in immunocompetent hosts and devastating, persistent diarrhea in immunocompromised individuals. There is no effective treatment for cryptosporidiosis and little is known about the basic biology of the organism. Cloning and sequence analysis of the gene encoding GP900, a previously identified > 900 kDa glycoprotein, predicts a mucin-like glycoprotein composed of distal cysteine-rich domains separated by polythreonine domains and a large membrane proximal N-glycosylated core region. A trinucleotide repeat composed predominantly of the triplet ACA encodes the threonine domains. GP900 is stored in micronemes prior to appearance on the surface of invasive forms. The concentration of native GP900 which inhibits 50% (IC50) of invasion in vitro is low picomolar; the IC50 for a recombinant cysteine rich-domain is low nanomolar. These observations indicate that GP900 is a parasite ligand for a host receptor involved in attachment/invasion and suggest that immunotherapy or chemotherapy directed against GP900 may be feasible.
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Affiliation(s)
- D A Barnes
- Department of Medicine, University of California-San Francisco General Hospital, 94110, USA
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26
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Joe A, Verdon R, Tzipori S, Keusch GT, Ward HD. Attachment of Cryptosporidium parvum sporozoites to human intestinal epithelial cells. Infect Immun 1998; 66:3429-32. [PMID: 9632617 PMCID: PMC108364 DOI: 10.1128/iai.66.7.3429-3432.1998] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/1997] [Accepted: 04/08/1998] [Indexed: 02/07/2023] Open
Abstract
An enzyme-linked immunosorbent assay-based attachment model using the human intestinal cell line Caco-2A was developed to study attachment of Cryptosporidium parvum sporozoites in vitro and to assess potential inhibitors of sporozoite binding. In this system, attachment was related to sporozoite dose, incubation time, and host cell differentiation status. Polyclonal antibodies to C. parvum as well as glycoprotein inhibitors of a sporozoite lectin reduced attachment. This model will be a valuable tool in elucidating specific molecules and mechanisms involved in sporozoite-host cell attachment.
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Affiliation(s)
- A Joe
- Division of Geographic Medicine and Infectious Diseases, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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27
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Liang FT, Granstrom DE, Zhao XM, Timoney JF. Evidence that surface proteins Sn14 and Sn16 of Sarcocystis neurona merozoites are involved in infection and immunity. Infect Immun 1998; 66:1834-8. [PMID: 9573058 PMCID: PMC108132 DOI: 10.1128/iai.66.5.1834-1838.1998] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/1997] [Accepted: 01/29/1998] [Indexed: 02/07/2023] Open
Abstract
Sarcocystis neurona is the etiologic agent of equine protozoal myeloencephalitis (EPM). Based on an analysis of 25,000 equine serum and cerebrospinal fluid (CSF) samples, including samples from horses with neurologic signs typical of EPM or with histologically or parasitologically confirmed EPM, four major immunoblot band patterns have been identified. Twenty-three serum and CSF samples representing each of the four immunoblot patterns were selected from 220 samples from horses with neurologic signs resembling EPM and examined for inhibitory effects on the infectivity of S. neurona by an in vitro neutralization assay. A high correlation between immunoblot band pattern and neutralizing activity was detected. Two proteins, Sn14 and Sn16 (14 and 16 kDa, respectively), appeared to be important for in vitro infection. A combination of the results of surface protein labeling, immunoprecipitation, Western blotting, and trypsin digestion suggests that these molecules are surface proteins and may be useful components of a vaccine against S. neurona infection. Although S. neurona is an obligate intracellular parasite, it is potentially a target for specific antibodies which may lyse merozoites via complement or inhibit their attachment and penetration to host cells.
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Affiliation(s)
- F T Liang
- Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington 40546-0099, USA
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28
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Abstract
The view that antibody-mediated protection is unimportant against intracellular pathogens is not supported by the literature. In fact, there is convincing evidence that antibody can protect against many important intracellular pathogens. The challenge now is to identify antigens that elicit protective antibodies, use them in vaccine design and understand how humoral and cellular immune mechanisms cooperate.
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Affiliation(s)
- A Casadevall
- Dept of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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29
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Graczyk TK, Cranfield MR, Helmer P, Fayer R, Bostwick EF. Therapeutic efficacy of hyperimmune bovine colostrum treatment against clinical and subclinical Cryptosporidium serpentis infections in captive snakes. Vet Parasitol 1998; 74:123-32. [PMID: 9561700 DOI: 10.1016/s0304-4017(97)00153-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Therapy based on the protective passive immunity of Hyperimmune Bovine Colostrum (HBC) (raised against Cryptosporidium parvum in dairy cows immunized during gestation) was tested for heterologous efficacy in subclinical and clinical infections of 12 captive snakes with C. serpentis. Six gastric HBC treatments of 1% snake weight at 1-week intervals each, have histologically cleared C. serpentis in three subclinically infected snakes, and regressed gastric histopathological changes in one of these snakes. In all snakes, each subsequent HBC treatment significantly decreased the number of oocysts recovered in gastric lavage eluants (P < 0.03). The treatments induced oocyst-negative gastric eluants and stools in all snakes, and improved clinical signs of infection. Clinically infected snakes displayed severe histopathological changes in the gastric region; however, the numbers of developmental stages of C. serpentis were moderate. Considering the severity of pathology, much lower than expected pathogen numbers were observed, and it is believed that clinically infected snakes did not have enough time to repair tissue damage that had occurred over the years of infection. As the HBC treatment was safe and highly efficacious, it is recommended to gastrically administer the HBC therapeutically to snakes that are clinically or subclinically infected with C. serpentis. Hyperimmune bovine colostrum can also be used in snake supportive therapy or prophylaxis.
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Affiliation(s)
- T K Graczyk
- Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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30
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Carter GM. HIV-related diarrhea: urgent need for a reasoned holistic response. J Altern Complement Med 1997; 3:169-72. [PMID: 9395708 DOI: 10.1089/acm.1997.3.169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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31
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Theodos CM, Sullivan KL, Griffiths JK, Tzipori S. Profiles of healing and nonhealing Cryptosporidium parvum infection in C57BL/6 mice with functional B and T lymphocytes: the extent of gamma interferon modulation determines the outcome of infection. Infect Immun 1997; 65:4761-9. [PMID: 9353062 PMCID: PMC175683 DOI: 10.1128/iai.65.11.4761-4769.1997] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This study describes healing and nonhealing models of Cryptosporidium parvum infection with adult mice that have functional T and B lymphocytes. In our nonhealing model, mice on a C57BL/6 background which have a targeted disruption in the gamma interferon (IFN-gamma) gene (GKO mice) are utilized. C. parvum-infected GKO mice shed extremely high levels of oocysts and displayed overwhelming infection of the entire small intestine. The majority of these mice succumbed within 2 to 3 weeks due to severe acute infection and profound mucosal destruction. In our healing murine model, C57BL/6J mice treated with a single injection of the neutralizing anti-IFN-gamma monoclonal antibody XMG 1.2 prior to infection were used. These mice developed two peaks of oocyst shedding but were ultimately free of parasites on day 30 of infection. Again, the small intestine was the primary site of infection. Mesenteric lymph node (MLN) cells isolated from C. parvum-infected nonhealing GKO mice proliferated and secreted interleukin 2 (IL-2) but not IFN-gamma or IL-4 in response to ex vivo restimulation with intact C. parvum sporozoites or a C. parvum sporozoite antigen preparation. In contrast, parasite-specific MLN cells isolated from healing C57BL/6J mice secreted IL-2 and IFN-gamma but not IL-4. These results suggest that IFN-gamma, either directly or indirectly, is important for resistance to and resolution of cryptosporidiosis. Moreover, these models now allow the analysis of parasite-specific cell-mediated and humoral mucosal immune responses to determine what constitutes protective immunity to C. parvum.
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Affiliation(s)
- C M Theodos
- Department of Biomedical Sciences, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
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32
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Casadevall A, Goldman D, Feldmesser M. Antibody-based therapies for infectious diseases : renaissance for an abandoned arsenal? ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0020-2452(97)83532-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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33
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Greenberg PD, Cello JP. Treatment of severe diarrhea caused by Cryptosporidium parvum with oral bovine immunoglobulin concentrate in patients with AIDS. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1996; 13:348-54. [PMID: 8948373 DOI: 10.1097/00042560-199612010-00008] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We prospectively evaluated the safety and efficacy of colostrum-derived bovine immunoglobulin concentrate in the treatment of diarrhea caused by Cryptosporidium parvum in patients with AIDS. A total of 24 patients with severe chronic diarrhea and AIDS were stratified to one of three cohorts: (1) C. parvum infection alone (n = 16), (2) C. parvum and a second opportunistic infection (n = 4), and (3) idiopathic AIDS enteropathy with no identified source of infection (n = 3) or an untreatable opportunistic infection other than C. parvum (n = 1). All patients were treated with bovine immunoglobulin concentrate for 21 consecutive days. Patients in cohort 1 were randomized to receive the medication in powder or capsule forms, whereas all patients in cohorts 2 and 3 received the powder form. The primary end point was change in mean daily stool weight. Secondary end points included change in stool frequency and body weight, as well as clearance of C. parvum oocytes as analyzed on stool microscopy. Patients with C. parvum who were treated with bovine immunoglobulin concentrate in powder form experienced a significant decrease in mean stool weight, from 1,158 +/- 114 g/day at baseline, to 595 +/- 63 g/day (p = 0.04) at the end of treatment, and 749 +/- 123 g/day (p = 0.03) 1 month after completing treatment. Stool frequency decreased from 6.6 +/- 0.6 bowel movements per day at study entry, to 5.4 +/- 0.7 during treatment (p = 0.04), and 5.4 +/- 0.9 during observation (p = 0.12). Patients who received bovine immunoglobulin concentrate in capsule form and patients without C. parvum (cohort 3) showed no improvement. No serious side effects were observed, and the medication was well tolerated. Thus, bovine colostrum immunoglobulin concentrate, in powder form, appears promising in the treatment of severe diarrhea caused by C. parvum. The optimal dosage, duration of therapy, and overall efficacy need to be determined in placebo-controlled trials.
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Affiliation(s)
- P D Greenberg
- Division of Gastroenterology, Hepatology, and Clinical Nutrition, San Francisco General Hospital 94110, USA
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34
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Perryman LE, Jasmer DP, Riggs MW, Bohnet SG, McGuire TC, Arrowood MJ. A cloned gene of Cryptosporidium parvum encodes neutralization-sensitive epitopes. Mol Biochem Parasitol 1996; 80:137-47. [PMID: 8892291 DOI: 10.1016/0166-6851(96)02681-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Two mAb, C6B6 and 7D10, each significantly reduced infection of mice by Cryptosporidium parvum and reacted with a 23-kDa glycoprotein (p23) of geographically disperse C. parvum isolates. The antibodies were used to identify plaques in a cDNA library prepared from C. parvum sporozoite mRNA. cDNA insert sequences from positive plaques were determined and used to isolate additional clones encoding p23 coding sequences. A consensus open reading frame of 333 base pairs, encoding 111 amino acids, was identified in this collection of cDNAs. The predicted amino acid sequence contained one N-glycosylation site, but lacked hydrophobic membrane spanning regions. Epitope mapping revealed that mAb 7D10 defines the linear epitope QDKPAD which occurs twice in the C terminal region of the peptide encoded by the ORF. This same C terminal peptide region contains a non-linear epitope bound by mAb C6B6. Serum from mice immunized with synthetic C terminal peptide reacted with sporozoite p23. The occurrence of neutralization-sensitive epitopes encoded by defined regions of the C. parvum genome suggests that recombinant proteins or synthetic peptides containing these epitopes may prove useful for inducing immune responses that diminish infection.
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Affiliation(s)
- L E Perryman
- Department of Microbiology, Pathology, and Parasitology, North Carolina State University, Raleigh, NC 27606, USA.
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35
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Yang S, Healey MC, Du C, Zhang J. Complete development of Cryptosporidium parvum in bovine fallopian tube epithelial cells. Infect Immun 1996; 64:349-54. [PMID: 8557363 PMCID: PMC173767 DOI: 10.1128/iai.64.1.349-354.1996] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Cryptosporidium parvum is a coccidian parasite responsible for causing protracted and life-threatening diarrheal illness in immunocompromised humans, especially patients with AIDS. The lack of medications effective in treating people suffering from cryptosporidiosis has prompted the development of in vivo and in vitro models for this disease. This study is the first to demonstrate that C. parvum can complete its entire life cycle (from sporozoite to infective oocyst) in a primary culture of bovine fallopian tube epithelial (BFTE) cells. Scanning and transmission electron photomicrographs were used to detail the ultrastructure of individual parasitic stages. Successful infections were produced by inoculating cell cultures with either oocysts or purified sporozoites. Infection of BFTE cells with C. parvum close paralleled in vivo infections with regard to host cell location and chronology of parasite development. Infecting BFTE cells with sporulated oocysts provided a reproducible and quantitative cultivation system with significantly (P < or = 0.001) higher infection rates than in Madin-Darby canine kidney cells. Oocysts produced in BFTE cells were infective for immunosuppressed adult C57BL/6N mice. Cultivation of C. parvum in BFTE cells will facilitate the study of interactions between parasites and host cells as well as provide a reliable system for evaluating anticryptosporidial compound efficacy.
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Affiliation(s)
- S Yang
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322-5600, USA
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36
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Abstract
Cryptosporidium parvum is a protozoan which can cause severe debilitating disease in immunocompromised individuals. Animal models have shown that cellular immunity is the most important factor against the development of the disease. Individuals with a humoral immune deficiency are also at risk. In HIV-infected patients there is a clear relationship between disease severity and CD4 cell counts. Insight into the pathogenesis and development of new agents is hampered by the lack of an in vitro culture system. Prevention is of the utmost importance due to the difficulties of therapy and the severity of clinical disease which can develop. Oocysts are highly resistant to commonly used disinfectants. In HIV-infected patients with cryptosporidiosis, antiretroviral therapy should be instituted or modified. Moreover, non-specific therapy with antidiarrhoeal agents should also be instituted. If no effect is seen, therapy with paromomycin 500 mg 4 times daily for 2-3 weeks should be initiated, followed by maintenance therapy with 500 mg twice daily to prevent relapse.
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Affiliation(s)
- I M Hoepelman
- Department of Medicine, Eijkman Winkler Laboratory for Medical Microbiology, University Hospital, Utrecht, The Netherlands
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Kuhls TL, Orlicek SL, Mosier DA, Crawford DL, Abrams VL, Greenfield RA. Enteral human serum immunoglobulin treatment of cryptosporidiosis in mice with severe combined immunodeficiency. Infect Immun 1995; 63:3582-6. [PMID: 7642294 PMCID: PMC173497 DOI: 10.1128/iai.63.9.3582-3586.1995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The anti-cryptosporidial immunoglobulin G antibodies in two commercially available human serum immunoglobulin (HSIG) products were quantified and characterized. The mean level of Cryptosporidium parvum-specific immunoglobulin G in HSIG was eightfold higher than the antibody level found in the sera of three immunocompetent individuals convalescing from cryptosporidiosis. However, HSIG products displayed no reactivity to cryptosporidial antigens in immunoblot analyses, while convalescent-phase sera demonstrated characteristic banding patterns. When HSIG was given to newborn severe combined immunodeficiency (scid) mice before and shortly after experimental infection, a decreased intensity of infection was observed in the intestines of the mice compared with that of control mice. However, there was no difference in mortality or histopathologic findings in the intestines of HSIG-treated and control mice when treatment was not started until 22 days of age. These results indicate that HSIG may be beneficial when given prophylactically; however, HSIG cannot eradicate cryptosporidia from mucosal surfaces in an established infection.
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Affiliation(s)
- T L Kuhls
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA
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Tatalick LM, Perryman LE. Attempts to protect severe combined immunodeficient (scid) mice with antibody enriched for reactivity to Cryptosporidium parvum surface antigen-1. Vet Parasitol 1995; 58:281-90. [PMID: 8533267 DOI: 10.1016/0304-4017(94)00729-v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cryptosporidium parvum is a protozoal pathogen which infects the gastrointestinal epithelium of mammals causing diarrhoea, the duration and severity of which is determined by the immunocompetency of the host. Currently, there is no effective treatment or prevention. We evaluated the ability of surface antigen-1 (SA-1), defined as those antigens recognized by neutralizing mAb 17.41, to elicit a protective antibody response when used as an immunogen. A SA-1 enriched fraction was obtained by immunoaffinity chromatography and was used to immunize a naive Holstein calf. SA-1 immune serum from this calf detected C. parvum epitopes to a 1:10,000 dilution in a dot blot assay, and sporozoite surface epitopes at a 1:10,000 dilution in a live immunofluorescence assay. Western blot analysis showed that SA-1 immune bovine serum recognized a similar pattern of C. parvum antigens as the defining mAb 17.41. Oral passive transfer of SA-1 immune bovine serum did not protect severe combined immunodeficient (scid) mice or suckling BALB/c mice from initial infection with C. parvum, or terminate a persistent infection in scid mice.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Protozoan/immunology
- Antigens, Protozoan/administration & dosage
- Antigens, Protozoan/immunology
- Antigens, Protozoan/isolation & purification
- Antigens, Surface/administration & dosage
- Antigens, Surface/immunology
- Antigens, Surface/isolation & purification
- Cattle
- Cryptosporidiosis/immunology
- Cryptosporidiosis/prevention & control
- Cryptosporidium parvum/immunology
- Female
- Immunization, Passive
- Male
- Mice
- Mice, Inbred BALB C
- Mice, SCID
- Protozoan Vaccines/administration & dosage
- Protozoan Vaccines/immunology
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Affiliation(s)
- L M Tatalick
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman 99164-7040, USA
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Benhamou Y, Kapel N, Hoang C, Matta H, Meillet D, Magne D, Raphael M, Gentilini M, Opolon P, Gobert JG. Inefficacy of intestinal secretory immune response to Cryptosporidium in acquired immunodeficiency syndrome. Gastroenterology 1995; 108:627-35. [PMID: 7875465 DOI: 10.1016/0016-5085(95)90433-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND/AIMS An alteration of the secretory immune response has been forwarded to explain frequent and chronic mucosal infections in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to explore the intestinal immunoglobulin (Ig) secretions in patients with AIDS and their relationships to cryptosporidiosis. METHODS Patients with AIDS and enteric cryptosporidiosis (n = 12), other enteric infections (n = 10), and no identifiable enteric pathogen (n = 10) and human immunodeficiency virus-seronegative controls (n = 18) were studied. The number of intestinal IgA and IgM plasma cells of the duodenal lamina propria mucosa and total and anti-Cryptosporidium IgA, IgM, and IgG were measured in serum and feces. RESULTS Although not significantly increased, the number of IgA and IgM plasma cells was greater in patients with AIDS (n = 20) than in controls (n = 5). In feces, total IgA outputs and specific anti-Cryptosporidium IgA levels were significantly higher in patients with AIDS and cryptosporidiosis than in the two other groups of patients with AIDS (P < 0.05 and P < 0.01, respectively) and controls (P < 0.001 and P < 0.01, respectively). Total fecal IgM output and specific anti-Cryptosporidium IgM coproantibodies were increased only in the Cryptosporidium-infected patients relative to the controls (P < 0.05). CONCLUSIONS Despite the development of pathogen-specific mucosal antibody responses, patients with AIDS and cryptosporidiosis fail to clear the parasite.
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Affiliation(s)
- Y Benhamou
- Service d'Hépato-Gastroentérologie, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
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40
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Affiliation(s)
- P J O'Donoghue
- Parasitology Section, VETLAB, Department of Primary Industries, Adelaide, Australia
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41
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Tzipori S, Rand W, Griffiths J, Widmer G, Crabb J. Evaluation of an animal model system for cryptosporidiosis: therapeutic efficacy of paromomycin and hyperimmune bovine colostrum-immunoglobulin. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1994; 1:450-63. [PMID: 8556484 PMCID: PMC368287 DOI: 10.1128/cdli.1.4.450-463.1994] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Several immunodeficient rodent models currently exist in which persistent, largely asymptomatic, Cryptosporidium parvum infections can be established. Piglets, in contrast, develop a self-limiting diarrheal illness. We have consequently developed an animal model system in which scid mice were used to screen drugs for inhibitory activity against C. parvum, after which the drugs' therapeutic potential was evaluated with piglets. Paromomycin and hyperimmune bovine colostrum-immunoglobulin were selected to evaluate this system. C. paravum infections in suckling scid mice tended to be associated with villus surfaces, while in weaned and in older scid mice infections were more commonly localized in abscessed crypts. Rates of oocyst shedding in suckling scid mice were 50 to 200 times higher than in weaned mice and therefore made suckling mice a considerably more sensitive model for drug testing. Paromomycin given in high doses over 9 to 10 days was not toxic to either scid mice (3,000 mg/kg of body weight per day) or piglets (500 mg/kg/day). Paromomycin treatment was very effective against villus surface infections in suckling mice and considerably less effective against infections in inaccessible sites such as abscessed crypts and stomach pits seen in weaned and adult scid mice. The therapeutic efficacy of paromomycin in piglets depended on the severity of the diarrheal illness. Mild to moderate diarrhea and infection were cleared after paromomycin treatment of piglets infected with one C. parvum isolate. However, paromomycin had no impact on severely affected piglets infected with a second isolate, presumably because of a rapid transit time through the gut. In contrast to paromomycin hyperimmune bovine colostrum-immunoglobulin treatment reduced the rate of C. parvum infection moderately in scid mice and only slightly in piglets, again probably because of a rapid transit time through the gut and inactivation in the stomach. It was also clear that the impact of effective drugs against C. parvum can be detected within 5 days after the onset of treatment in either model.
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Affiliation(s)
- S Tzipori
- Department of Comparative Medicine, Tufts University School of Veterinary Medicine, Grafton, Massachusetts 01536, USA
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