Limits...
An Irish perspective on Cryptosporidium. Part 1.

Zintl A, Mulcahy G, de Waal T, de Waele V, Byrne C, Clyne M, Holden N, Fanning S - Ir Vet J (2006)

Bottom Line: Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood.Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland.The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks.

View Article: PubMed Central - HTML - PubMed

Affiliation: UCD School of Agriculture, Food Science and Veterinary Medicine and Conway Institute of Biomedical and Biomolecular Research, University College Dublin, Ireland.

ABSTRACT
Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island.

No MeSH data available.


Related in: MedlinePlus

Identification of C. hominis (lanes 2, 3 and 5, 6) and C. parvum (lanes 4 and 7) by PCR-RFLP. Digestion with the endonuclease Sspl results in products of approx 500 and 250 bp in both spp. Digestion with the endonuclease Vspl renders products of approx 590 (C. hominis) and 610 bp (C. parvum). Lanes 1 and 8 are molecular weight markers.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3113892&req=5

Figure 4: Identification of C. hominis (lanes 2, 3 and 5, 6) and C. parvum (lanes 4 and 7) by PCR-RFLP. Digestion with the endonuclease Sspl results in products of approx 500 and 250 bp in both spp. Digestion with the endonuclease Vspl renders products of approx 590 (C. hominis) and 610 bp (C. parvum). Lanes 1 and 8 are molecular weight markers.

Mentions: In all, there are currently 15 recognised species of Cryptosporidium [48,39,14]. The main species infecting humans are C. hominis and C. parvum. Reports of natural infections with C. hominis have been restricted to humans so far, with the exception of two cases identified last year in Scottish cattle [41]. Experimental infections with C. hominis have been carried out in neonatal pigs and lambs [33]. In contrast, C. parvum infects most, if not all, mammals including humans and is a major pathogen of calves. Recent studies suggest that a number of other zoonotic species, particularly the avian pathogen, C. meleagridis, also cause diarrhoea in humans. Morphologically indistinguishable, the various species are most easily discriminated genetically, mostly by polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) analysis [25] (Figure 4). Most work to date on the biology and pathogenicity of Cryptosporidium in relation to human infection has been done using C. parvum. Therefore, compared to C. parvum, little is known of the biology of invasion of the human-restricted C. hominis. Recent studies carried out in the Children's Research Centre, Our Lady's Hospital for Sick Children, Crumlin, Dublin, indicate that there is diversity in the mechanisms used by C. parvum and C. hominis to infect cells of different origin [22,23]. More specifically, it was shown that host cell invasion by the two species was mediated by different receptor-ligand interactions. For instance, while a galactose-N-acetylgalactosamine (Gal/GalNAc)-specific sporozoite epitope is crucial for host cell invasion by C. parvum, [6], Hashim et al. [22] found that in vitro, C. hominis interacted with potential host cells via a Gal/GalNAc-independent mechanism. These data have important implications for understanding the pathogenesis of cryptosporidiosis and for improved chemotherapy.


An Irish perspective on Cryptosporidium. Part 1.

Zintl A, Mulcahy G, de Waal T, de Waele V, Byrne C, Clyne M, Holden N, Fanning S - Ir Vet J (2006)

Identification of C. hominis (lanes 2, 3 and 5, 6) and C. parvum (lanes 4 and 7) by PCR-RFLP. Digestion with the endonuclease Sspl results in products of approx 500 and 250 bp in both spp. Digestion with the endonuclease Vspl renders products of approx 590 (C. hominis) and 610 bp (C. parvum). Lanes 1 and 8 are molecular weight markers.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3113892&req=5

Figure 4: Identification of C. hominis (lanes 2, 3 and 5, 6) and C. parvum (lanes 4 and 7) by PCR-RFLP. Digestion with the endonuclease Sspl results in products of approx 500 and 250 bp in both spp. Digestion with the endonuclease Vspl renders products of approx 590 (C. hominis) and 610 bp (C. parvum). Lanes 1 and 8 are molecular weight markers.
Mentions: In all, there are currently 15 recognised species of Cryptosporidium [48,39,14]. The main species infecting humans are C. hominis and C. parvum. Reports of natural infections with C. hominis have been restricted to humans so far, with the exception of two cases identified last year in Scottish cattle [41]. Experimental infections with C. hominis have been carried out in neonatal pigs and lambs [33]. In contrast, C. parvum infects most, if not all, mammals including humans and is a major pathogen of calves. Recent studies suggest that a number of other zoonotic species, particularly the avian pathogen, C. meleagridis, also cause diarrhoea in humans. Morphologically indistinguishable, the various species are most easily discriminated genetically, mostly by polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) analysis [25] (Figure 4). Most work to date on the biology and pathogenicity of Cryptosporidium in relation to human infection has been done using C. parvum. Therefore, compared to C. parvum, little is known of the biology of invasion of the human-restricted C. hominis. Recent studies carried out in the Children's Research Centre, Our Lady's Hospital for Sick Children, Crumlin, Dublin, indicate that there is diversity in the mechanisms used by C. parvum and C. hominis to infect cells of different origin [22,23]. More specifically, it was shown that host cell invasion by the two species was mediated by different receptor-ligand interactions. For instance, while a galactose-N-acetylgalactosamine (Gal/GalNAc)-specific sporozoite epitope is crucial for host cell invasion by C. parvum, [6], Hashim et al. [22] found that in vitro, C. hominis interacted with potential host cells via a Gal/GalNAc-independent mechanism. These data have important implications for understanding the pathogenesis of cryptosporidiosis and for improved chemotherapy.

Bottom Line: Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood.Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland.The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks.

View Article: PubMed Central - HTML - PubMed

Affiliation: UCD School of Agriculture, Food Science and Veterinary Medicine and Conway Institute of Biomedical and Biomolecular Research, University College Dublin, Ireland.

ABSTRACT
Cryptosporidiosis, a protozoal disease which causes significant morbidity in humans, is one of the chief causes of diarrhoea in neonatal ruminants. Although the parasite poses a significant threat to public health and animal health in Ireland, its epidemiology on the island is only poorly understood. Environmental studies have shown the waterborne parasite to be widespread in some untreated waterbodies around Ireland. The island's hydrogeological situation, combined with high stocking rates of livestock and the absence of filtration from regular water treatment, render it vulnerable to large-scale outbreaks. This review discusses the parasite in the Irish context and underlines the need for a reference facility to provide active surveillance on the island.

No MeSH data available.


Related in: MedlinePlus