Occurrence and molecular characterization ofEnterocytozoon bieneusiin wild and domestic animal species in Portugal

Abstract

The phylum Microsporidia encompasses a diverse group of obligate, intracellular, and spore-forming organisms able to infect a wide range of animal hosts. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and animals. Little is known about the presence and epidemiology of E. bieneusi in wildlife. We investigated E. bieneusi occurrence and genetic diversity in wild and domestic mammals, through molecular-detection methods, from different regions across Portugal. A total of 756 samples were collected from 288, 242 and 226 wild carnivores, wild ungulates, and domestic animals, respectively. Overall, eight specimens were E. bieneusi-positive (1.1%, 8/756) obtained from five wild (Iberian lynx, Iberian wolf, red fox, stone marten, and wild boar) and one domestic (sheep) host. Nucleotide sequence analysis identified four genotypes of E. bieneusi, Type IV, Wildboar3, BEB6 and PtEbIX. Three of those genotypes belong to Groups 1 (Type IV and Wildboar3) and 2 (BEB6), which are known to contain genotypes capable of infecting a variety of hosts, including humans, highlighting their public health importance. PtEbIX belongs to the dog-specific Group 11. This study represents the first, largest and most comprehensive molecular-based epidemiology survey carried out in Portugal in wild and domestic animals to date and the first worldwide identification of E. bieneusi in wolf species. Our study showed that wild carnivores and ungulates are reservoirs of zoonotic genotypes of E. bieneusi, establishing their role in maintaining the sylvatic cycle of this parasite while representing a potential source of infection for humans and domestic animals.

Large-Scale Molecular Epidemiological Survey of Blastocystis sp. among Herbivores in Egypt and Assessment of Potential Zoonotic Risk

“…By analyzing our molecular data group by group, the highest frequency of the parasite was thus observed within the sheep cohort. A comparable prevalence has been documented in surveys examining a small number of fecal samples from this animal group and conducted in China (53.8%) [56], United Arab Emirates (63.6%) [57], and Portugal (60.9%) [58]. This frequency was therefore well above the average infection rate in sheep, estimated at around 25% worldwide from a systematic review and meta-analysis including over 3000 animals tested in 10 countries [59], thus emphasizing a frequent colonization of small ruminants in Egypt.…”

“…On the basis of recent reviews and supplementary epidemiological studies [12,31,39,58,59,63], no fewer than 20 STs have been currently identified in sheep worldwide including ST1-ST7, ST10, ST12, ST14, ST15, ST21, ST23-ST26, ST30, and ST42-ST44. The phylogenetic analysis performed in the present study allowed us to confirm the wide genetic diversity of isolates among single infections in sheep with the identification of 10 STs (ST1-ST3, ST5, ST10 (both subgroups a and b), ST14, ST21, ST24, ST26, and ST40), 9 of them already detected in previous surveys.…”

Molecular detection of Cryptosporidium spp. and Microsporidia in human and animal stool samples

“…Other study carried out in Australia showed an incidence of 4.4% (15/342) [31]. However, in a recent study carried out in Portugal, no positive samples for E. bieneusi were found in 46 fecal samples [32]. In addition, in our study we detected the presence of E. bieneusi in feces of a pig (20%; 1/5).…”

Molecular Detection of Cryptosporidium spp. and Microsporidia in Human and Animal Stool Samples

“…Another study carried out in Australia showed an incidence of 4.4% (15/342) [31]. However, in a recent study carried out in Portugal, no positive samples for E. bieneusi were found in 46 fecal samples [32]. Even so, our study indicates that dogs in urban settings are also prone to harbor E. bieneusi infections in addition to stray dogs, which may be more affected due to greater exposure to the parasite and poorer standards of care [15].…”