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Updated: May 15, 2026
Cost-effective Method for Microbial Source Tracking Using Specific Human and Animal Viruses
Published on: December 3, 2011
[Molecular characterization of Cryptosporidium spp. isolated in humans in two different locations in Spain]
Luis Navarro-I-Martinez1, Alexandre J da Silva, José Llovo Taboada
1División de Parasitología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, España.
Abstract:
Molecular PCR based diagnostic techniques have enabled us to distinguish between the different, morphologically identical, Cryptosporidium species that can infect humans. Of the 23 recognized species in the genus, at least 9 are able to infect humans. As the intensity of the clinical manifestations, pathogenicity, excretion of oocysts, and incidence, are different between this species, molecular studies are crucial for a better understanding of the epidemiology of human cryptosporidiosis. Samples form two independent studies are analyzed in this publication. One included 23 samples from Madrid, and the other, 72 samples from La Coruña. All of them positive for Cryptosporidium spp. by microscopic methods and belonging to isolated cases of human cryptosporidiosis. For the identification of the species responsible for the infection, the 18S rDNA diagnostic region and the COWP gene diagnostic regions were used. Out of the 95 samples tested, in 77 cases we were able to extract and amplify DNA. In those cases the species responsible for the infection were: C. parvum (40 cases, 2 Madrid and 38 La Coruña), C. hominis (30 cases, 10 Madrid and 20 La Coruña) and C. meleagridis (2 cases, 1 Madrid and 1 La Coruña). In 5 samples it was impossible to detect the species responsible for the infection, but their positivity was confirmed by PCR (4 Madrid and 1 La Coruña). The genotypes of the isolates from patients correlated well with animals from the same regions.
Insights
Molecular PCR techniques identify Cryptosporidium species in human infections. This study analyzed samples from Madrid and La Coruña, identifying C. parvum, C. hominis, and C. meleagridis, aiding understanding of cryptosporidiosis epidemiology.
Area of Science:
- Medical Parasitology
- Molecular Diagnostics
- Infectious Disease Epidemiology
Background:
- Morphologically identical Cryptosporidium species pose diagnostic challenges.
- At least 9 of 23 recognized Cryptosporidium species infect humans, with varying clinical impacts.
- Understanding species-specific epidemiology is crucial for managing human cryptosporidiosis.
Purpose of the Study:
- To molecularly identify Cryptosporidium species in human infections using samples from two independent studies.
- To correlate identified species and genotypes with geographical origin (Madrid and La Coruña).
- To enhance the understanding of human cryptosporidiosis epidemiology through precise species identification.
Main Methods:
- Polymerase Chain Reaction (PCR) based molecular techniques were employed.
- The 18S rDNA and COWP gene regions were used for species identification.
- DNA was extracted and amplified from 95 human cryptosporidiosis samples.
Main Results:
- Out of 95 samples, DNA was successfully amplified from 77.
- Identified species included Cryptosporidium parvum (40 cases), Cryptosporidium hominis (30 cases), and Cryptosporidium meleagridis (2 cases).
- Genotypes of patient isolates showed correlation with regional animal isolates.
Conclusions:
- Molecular methods effectively differentiate Cryptosporidium species in human infections.
- C. parvum and C. hominis are the predominant species causing cryptosporidiosis in the analyzed Spanish populations.
- The findings support the importance of molecular diagnostics in epidemiological studies of cryptosporidiosis.
