Abstract
BackgroundThe genetic characterization of Cryptosporidium and Giardia has important implications for investigating their epidemiology and underpins their control. We undertook the first molecular epidemiological survey of domestic bovids in selected regions of Sri Lanka to establish whether they excreted Cryptosporidium and/or Giardia with zoonotic potential.MethodsFaecal samples were collected from dairy calves (n = 340; Bos taurus; < 3 months of age; weekly sampling for six weeks) and water buffaloes (n = 297; Bubalus bubalis; <6 months and ≥6 months of age; one sampling) from seven different farms in Sri Lanka. Genomic DNAs were extracted from individual faecal samples and then tested for the presence of parasite DNA using a PCR-based mutation scanning-targeted sequencing-phylogenetic approach, employing genetic markers within the small subunit of nuclear ribosomal RNA and 60 kDa glycoprotein genes (designated pSSU and pgp60, respectively) for Cryptosporidium, and within the triose phosphate isomerise (ptpi) gene for Giardia.ResultsBased on pSSU sequence data, C. bovis, C. ryanae and six new genotypes that were genetically similar but not identical to C. andersoni (n = 1), C. bovis (n = 1), C. ryanae (n = 3) and C. suis (n = 1) were recorded in cattle. For pSSU, two other, new genotypes were defined in water buffalo, which were genetically most similar to Cryptosporidium genotypes recorded previously in this host species in other countries including Australia. Consistent with the findings for pSSU, no species or genotypes of Cryptosporidium with zoonotic potential were detected using pgp60. Based on ptpi sequence data, G. duodenalis assemblages A and E were detected in four and 137 samples from cattle, respectively, and assemblage E in two samples from water buffaloes.ConclusionsThe present study showed that C. parvum, the most commonly reported zoonotic species of Cryptosporidium recognised in bovine calves globally, was not detected in any of the samples from pre-weaned calves tested in the present study. However, eight new genotypes were recorded. Future studies of different host species in various regions are required to investigate the molecular epidemiology of cryptosporidiosis and giardiasis in Sri Lanka and neighbouring countries in South Asia.
Highlights
The genetic characterization of Cryptosporidium and Giardia has important implications for investigating their epidemiology and underpins their control
In the epidemiological context (Table 1), C. bovis and C. ryanae were detected in 5.6% and 7.4% of all samples only from farm AB, respectively, and the six new Cryptosporidium sequence types
Results of the present study suggest that the epidemiology of bovine cryptosporidiosis and giardiasis in Sri Lanka is distinct from those of other parts of the world
Summary
The genetic characterization of Cryptosporidium and Giardia has important implications for investigating their epidemiology and underpins their control. Cryptosporidium and Giardia are two parasitic protists that mainly infect the gastrointestinal tract and cause enteric disease in humans and various other animals [1,2]. An appraisal of the literature shows that the majority of molecular studies of Cryptosporidium and Giardia of cattle and other animals relates mainly to a limited number of countries in the developed world [3,27], but there is little published information for developing countries, including Sri Lanka. There have been numerous studies of cattle (Bos taurus) in many developed regions of the world [27], there have been few investigations of the molecular epidemiology of cryptosporidiosis and giardiasis in related bovids, such as water buffaloes (Bubalus bubalis) [28,29], which are common domesticated animals in many countries, in Asia
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
