Detection and molecular diversity of Giardia duodenalis and Cryptosporidium spp. in sheltered dogs and cats in Northern Spain

Genetic variability and transcontinental sharing of Giardia duodenalis infrapopulations determined by glutamate dehydrogenase gene

Microevolutionary data of Giardia duodenalis sub-assemblages is a prerequisite for determining the invasion zoonotic patterns of the parasite. To infer transmission patterns that could not be differentiated by the phenotypic features, a population genetic investigation is crucial for the elucidation of the genetic structure of G. duodenalis among the continents. Forty G. duodenalis positive fecal samples were collected from different foci of Northwest Iran. The specimens were subjected to Trichrome staining and sucrose gradient flotation. DNA samples were extracted, amplified, and sequenced by targeting glutamate dehydrogenase (gdh) gene. The global gdh sequences of sub-assemblages AII and BIV retrieved from NCBI GenBank were analyzed to estimate diversity indices, neutrality indices, and gene migration tests. Sequencing analyses indicated various levels of genetic variability of sub-assemblages AII and BIV among the five continents. Sub-assemblage BIV had greater genetic variability (haplotype diversity: 0.975; nucleotide diversity: 0.04246) than sub-assemblage AII. The statistical Fst value demonstrated that the genetic structure of sub-assemblages AII and BIV are moderately differentiated between European-American populations (Fst: 0.05352-0.15182), whereas a significant differentiation was not seen among other geographical population pairs. We conclude that a high gene flow of G. duodenalis sub-assemblages AII and BIV is unequivocally sharing among the continents. The current findings strengthen our knowledge to assess the evolutionary patterns of G. duodenalis in endemic foci of the world and it will become the basis of public health policy to control human giardiasis.

Opportunistic Protozoan Infections of Carnivores

Giardiasis and cryptosporidiosis are protozoan infections of the digestive tract and one of the most frequent causes of enteritis in dogs and cats, associated with acute and chronic diarrhoea. Generally, the risk of infection is higher for younger individuals in which the overall clinical picture and the course of disease are more serious. In this study we investigated the prevalence of giardiasis and cryptosporidiosis in dogs in Košice district of eastern Slovakia. From September 2015 until November 2016, we examined samples of faeces from 100 dogs from two shelters. Giardia duodenalis was diagnosed by the flotation method according to Faust, and by the molecular biologic method (Nested PCR). For the diagnosis of cryptosporidium oocysts, we used a staining method according to Kinyoun, and for detection of the presence of Cryptosporidium spp. a sandwich ELISA method. The total prevalence of these protozoan infections were 22 % (22/100), and of that, 19 % of the samples (19/100) were positive for Giardia duodenalis and 3 % (3/100) for the Cryptosporidium spp. In the shelter in Haniska, the giardia cysts were present in 9/54 samples (16.6 %) and cryptosporidia oocysts in 1/54 (1.85 %) samples of the faeces. In the Malá Farma shelter, 10/46 (21.73 %) samples were positive for G. duodenalis and 2/46 (4.34 %) showed positivity for Cryptosporidium spp.

Molecular detection and genetic characterizations of Cryptosporidium spp. in farmed foxes, minks, and raccoon dogs in northeastern China

Cryptosporidium spp. are common intestinal protozoa causing diarrhea in humans and a variety of animal species. With the recent development of fur industry, a large number of fur animals are farmed worldwide, especially in China. The existence of identical Cryptosporidium species/genotypes in humans and fur animals suggests zoonotic potential. In order to assess the presence of zoonotic Cryptosporidium species and/or genotypes in farmed fur animals, 367 fecal specimens were collected from 213 foxes, 114 minks and 40 raccoon dogs farmed in Heilongjiang, Jilin, and Liaoning provinces, northeastern China, during the period from June 2014 to October 2016. By PCR and sequencing of the partial small subunit (SSU) rRNA gene of Cryptosporidium, 20 of 367 (5.4%) animal samples were found to be infected, corresponding to 12 of 213 fox samples (5.6%) and 8 of 114 mink samples (7.0%) screened. Three Cryptosporidium species/genotypes were identified: C. canis (n = 17), C. meleagridis (n = 1) and Cryptosporidium mink genotype (n = 2). Two host-adapted C. canis types (C. canis dog genotype and C. canis fox genotype) were found. By PCR and sequencing of the partial 60 kDa glycoprotein (gp60) encoding gene, one mink genotype isolate was successfully subtyped as XcA5G1R1. The three Cryptosporidium species/genotypes identified in this study have been previously reported in humans suggesting that fur animals infected with Cryptosporidium spp. may pose a risk of zoonotic transmission of cryptosporidiosis, especially for the people working in fur animal farming and processing industry.

Identification of pig-specific Cryptosporidium species in mixed infections using Illumina sequencing technology

Nowadays molecular methods are widely used in epidemiological studies of Cryptosporidium infections in humans and animals. However to gain better understanding of parasite species or genotypes, especially when mixed infections are noticed, highly sensitive tools with adequate resolution power need to be employed. In this article, we report an application of the next generation sequencing method (NGS) for detection and characterisation of Cryptosporidium species concurrently present in pig faeces. A mixture of Cryptosporidium DNA obtained from two faecal samples was amplified at the 18 SSU rRNA gene locus and the resulting amplicons were subsequently used for MiSeq sequencing. Although initial molecular analyses indicated the possible presence of another Cryptosporidium species other than Cryptosporidium scrofarum and Cryptosporidium suis, deep sequencing only confirmed the presence of pig-specific Cryptosporidium.

Detection and multilocus genotyping of Giardia duodenalis in dogs in Sichuan province, China

Giardia duodenalis (also known as G. intestinalis) is a flagellated protozoan that parasitizes the small intestine and is a common causal agent of zoonotic infections in humans and animals. To assess the genetic diversity and zoonotic transmission potential of G. duodenalis in stray dogs, 159 fecal specimens were collected from dogs in Chengdu, Yaan, and Leshan in Sichuan province, China. Of the 159 fecal samples from stray dogs, 18 (11.3%) were G. duodenalis-positive based on nested PCR amplification of the beta giardin (bg) gene, and the occurrence varied from 1.8% to 35% in different cities. Dog-specific assemblages C (n = 9) and D (n = 9) were identified. The glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes of all bg-positive isolates were characterized. A total of 16 and 8 isolates were positive for the gdh and tpi genes, respectively. Two novel sequences of the bg locus were detected among genetic assemblage D isolates, and one novel gdh sequence and four novel tpi sequences were identified among genetic assemblage C isolates. Mixed infections of assemblages C and D were also detected. Assemblages A and B, which have high zoonotic potential, were not detected. Our results show that G. duodenalis is prevalent and a cause of diarrhea in dogs in Sichuan province, China.