Occurrence, risk factors and genotypes of Enterocytozoon bieneusi in dogs and cats in Guangzhou, southern China: high genotype diversity and zoonotic concern

Abstract

Background: Enterocytozoon bieneusi, a common opportunistic fungal pathogen, has a wide range of hosts. Limited epidemiological data on E. bieneusi intestinal infections in companion animals (dogs and cats) in China exists. In this study, fecal samples (651 from dogs and 389 from cats) in Guangzhou city, Guangdong Province, China, were collected, and the ribosomal internal transcribed (ITS) spacer region from the DNA extracted from them was Polymerase Chain Reaction (PCR)-amplified and sequenced. Results: Based on the sequencing data, E. bieneusi was identified in the fecal samples collected from 149 (22.9%) and 79 (20.3%) dogs and cats. Of the factors investigated, poor living conditions appeared to be the major risk factor for contracting the pathogen. Eleven E. bieneusi genotypes, six known (PtEb IX, GD1, D, CD9, EbpC, I) and five novel (designated here as GD2-GD6), were found in dogs. Eight genotypes, six known (PtEb IX, GD1, D, CD9, EbpC, Type IV) and two novel (GD2 and GC1), were identified in cats. Genotype PtEb IX was most common in both dogs and cats, followed by genotype GD1. Conclusions: Although PtEb IX was the most common E. bieneusi genotype in dogs, this is the first report of this genotype dominating in cats. The same genotype distribution of the pathogen between the two different companion animals species in the same geographic area indicates that inter-species transmission is probable. The widespread existence of zoonotic E. bieneusi genotypes (D, EbpC, Type IV) in companion animals indicates that they are potential sources of environmental contamination and infections in humans.

Prevalence and new genotypes of Enterocytozoon bieneusi in sheltered dogs and cats in Sichuan province, southwestern China

“…Genotype CD9 showed predominance, accounting for 67.6% (92/136). Genotype CD9 was also reported in dogs and cats in southern China [ 29 ]. Genotype PtEb IX was the second most common in the present study, which was also the predominant genotype in dogs in various countries [ 10 , 18 , 19 , 24 ].…”

“…Specifically, we found the prevalence of E. bieneusi in stray dogs was 18.8% (136/724), which was higher than that 8.6% (27/315) in dogs in eastern China [ 16 ], and in Shanghai, China 6% (29/485) [ 32 ]. In contrast, a more recent study in China revealed that the prevalence of E. bieneusi in dogs was 22.9% (149/651) [ 29 ]. In cats, 22 cats (14.1%) were found to be positive for E. bieneusi .…”

“…The discrepancy in E. bieneusi prevalence may be associated with the fact that the fecal samples detected in the present study included those from sheltered dogs and cats, which lived in poor living conditions. Importantly, it has been determined that the poor living conditions were a major risk factor for contracting E. bieneusi infections [ 29 ].…”

“…CD9 was the most common genotype in cats as well (50%, 11/22). In a previous study, CD9 has been identified in household cats in Guangzhou province, southern China [ 29 ]. Type IV and D were the most common genotypes in cats in previous studies [ 10 , 11 , 16 , 21 , 32 ].…”

“…In this study, genotype PtEb IX was found in only one fecal sample, which is consistent with a previous study in cats in China [ 10 ]. However, genotype PtEb IX was the most common in cats in another study [ 29 ]. The discrepancy in prevalence of different genotypes may be related to geographical differences.…”