First molecular subtyping and phylogeny of Blastocystis sp. isolated from domestic and synanthropic animals (dogs, cats and brown rats) in southern Iran

Abstract

Background Blastocystis sp. is a common intestinal protist that infects humans and many animals globally. Thus far, 22 subtypes (STs) have been identified in mammalian and avian hosts. Since various STs are common to humans and animals, it was suggested that some human infections might arise from zoonotic transmission. Therefore, the aim of this study was to assess the presence of Blastocystis sp. in domestic (dogs and cats) and synanthropic animals (rats) of Fars Province, Iran, and to genetically characterize the samples. Methods A total of 400 fresh faecal samples from 154 dogs, 119 cats, and 127 rats were inspected by direct microscopy, Wheatley’s trichrome staining, in vitro culture, and 18S rRNA gene nested-PCR. Finally, sequencing and phylogenetic analyses were performed. Results Out of 400 samples, 47 (11.8%) and 61 (15.3%) samples were detected as positive by direct wet mount and culture, respectively. Molecular analysis detected a larger number of positive samples ( n = 70, 17.5%): nested-PCR showed that 29 (18.8%) dogs, 21 (17.7%) cats, and 20 (15.8%) rats were infected by Blastocystis sp. Sequence analysis of positive samples indicated the presence of zoonotic STs in all investigated host species. Specifically, ST2 (allele 9), ST3 (allele 34), ST4 (allele 94), ST7 (allele 99), ST8 (allele 21), and ST10 (allele 152) were detected in dogs; ST1 (allele 2), ST3 (allele 34), ST4 (allele 94), ST10 (allele 152), and ST14 (allele 159) were detected in cats; and ST1 (allele 2), ST3 (allele 34), and ST4 (allele 92) were detected in rats. Conclusions Our data suggest that domestic dogs and cats can serve as possible reservoirs for in-contact humans, especially those who handle shelter-resident and client-owned animals. Moreover, rats as synanthropic animals can function as a potential source of human infections. Conversely, humans can act as a source of infections to animals. These results should be reinforced in future molecular epidemiological studies.

First identification and molecular subtyping of Blastocystis sp. in zoo animals in southwestern China

“…Blastocystis sp. has been identified in many animal hosts, such as NHPs, pigs, cattle, sheep, goats, dogs, birds, and various captive wildlife [ 23 , 24 , 33 ]. The prevalence of Blastocystis sp.…”

“…Blastocystis sp. has been reported in a substantial number of animal hosts, including livestock, companion animals, and captive wildlife, with greatly varying prevalence [ 22 – 24 ]. In recent years, several important intestinal zoonotic pathogens (e.g., Cryptosporidium , Giardia , and Microsporidia) have been reported in captive wildlife in China [ 25 , 26 ], highlighting wildlife may be potential reservoirs for human to contract these infectious agents.…”

First Molecular Characterisation of <i>Blastocystis</i> from Experimental Rats in Turkey and Comparison of the Frequencies Between Obese and Non-obese Groups

“…The authors examined totally 23 Blastocystis isolates from R. exulans and R. novercious, all were belonged to Blastocystis ST4. A study from southern Iran reported that 15.8% of rats were infected with Blastocystis and three subtypes were detected, including ST4, ST3, and ST1 (20). The distribution of Blastocystis subtypes was studied among symptomatic patients in Manisa and İzmir: ST3 (44.7%), ST1 (13.8%), ST2 (11.7%), ST6 (1%), ST7 (1.1%) and ST2+ST3 (2.1%) (21).…”

Use of Oxford Nanopore MinION to generate full-length sequences of the Blastocystis small subunit (SSU) rRNA gene

“…Blastocystis sp. is a common enteric protist parasite of humans and animals [ 1 , 2 ]. It has a global distribution and is one of the most common human intestinal parasites in both developed and developing countries [ 3 , 4 ].…”