Molecular detection of Enterocytozoon bieneusi in farm-raised pigs in Hainan Province, China: infection rates, genotype distributions, and zoonotic potential

Abstract

Enterocytozoon bieneusi is a zoonotic fungal pathogen with a high degree of host diversity that can parasitize many animals, including humans. Pigs may play an important role in the epidemiology of E. bieneusi as reservoir hosts. Nevertheless, the genotypes of E. bieneusi in pigs in China remain poorly understood. The aim of this study was to determine the prevalence of E. bieneusi infection amongst pigs raised on farms from four cities of Hainan Province, using nested polymerase chain reaction (PCR) of the partial small subunit of the ribosomal RNA gene, and to identify genotypes of E. bieneusi isolates based on sequence analysis of the ribosomal internal transcribed spacer (ITS) region. Among 188 stool samples, E. bieneusi was detected in 46.8% (88/188). Eight genotypes including four known (EbpA, CS-4, MJ14, and CHG19) and four novel (HNP-I -HNP-IV) genotypes were identified. Using phylogenetic analysis, genotypes EbpA, CS4, CHG19, HNP-III, and HNP-IV were clustered into zoonotic Group 1, while the remaining three genotypes (MJ14, HNP-I, and HNP-II) clustered into Group 10. The high prevalence of zoonotic genotypes of E. bieneusi among pigs suggests that pig farming is a potential source of human infection. Additionally, this is the first identification of genotypes in Group 10 in pigs indicating unique epidemic features of E. bieneusi in pigs in Hainan Province, the southernmost part of China.

Enterocytozoon bieneusi (Microsporidia): Identification of novel genotypes and evidence of transmission between sympatric wild boars ( Sus scrofa ferus ) and Iberian pigs ( Sus scrofa domesticus ) in Southern Spain

“…bieneusi in wildlife has previously been documented in wild carnivores including European badgers (Meles meles, 23%), beech martens (Martes foina, 11%) and red foxes (Vulpes vulpes, 9-14%) (Galván-Díaz et al, 2014;Santín et al, 2018). EbpA, the most prevalent genotype in this study in Iberian pigs and wild boars, is commonly reported in pig worldwide (Zhou et al, 2020). It was also the most abundant genotype in a survey in wild boar in Central Europe (Němejc et al, 2014) and…”

Genotyping and zoonotic potential of Enterocytozoon bieneusi in cattle farmed in Hainan Province, the southernmost region of China

“…Sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene has revealed more than 500 genotypes (142 in humans, of which 49 were also identified in animals) [ 11 , 20 , 54 ]. Phylogenetic comparative analyses clustered all genotypes into eleven major genetic groups.…”

Prevalence, genetic diversity and implications for public health of Enterocytozoon bieneusi in various rodents from Hainan Province, China

“…Group 1 or 2 are frequently reported in pets, non-human primates, wildlife, and livestock (pigs, cattle, sheep, etc.) [5,8]. However, the mechanism of transmission of infection from a specific animal to humans is unclear.…”

“…These studies involved five provinces with infection rates ranging from 3.6% to 35.1% [12][13][14][15][16][17][18][19][20]. In Hainan Province in China there is a high number of rodents that are in close contact with humans and other animals and there is a high prevalence of E. bieneusi in farmed, household, and wild animals [8,9,26,27]. Thus, it is necessary to understand E. bieneusi epidemiology in rodents to prevent pathogen infection in humans as well as in other animals.…”

“…Previous studies detected E. bieneusi using PCR-based assays with appropriate gene markers [ 7 ]. More than 500 genotypes, of which 142 infected humans and 49 infected both humans and animals, were identified through the internal transcribed spacer (ITS) sequence analysis of rDNA of E. bieneusi [ 5 , 8 , 9 ]. These genotypes were grouped into 11 genetically isolated clusters by phylogenetic analysis [ 5 ].…”