First report and molecular prevalence of potential zoonotic Enterocytozoon bieneusi in Turkish tumbler pigeons (Columba livia domestica)

The global epidemiology of Microsporidia infection in birds: A systematic review and meta-analysis

This study aimed to assess the global status and genetic diversity of Microsporidia infection in different birds. An online search was conducted in international databases from 1 January 1990 to 30 June 2022. A total of 34 articles (including 37 datasets) were included for the final meta-analysis. The pooled global prevalence of Microsporidia infection in birds was 14.6% (95% CI: 11.6-18.1). The highest prevalence of Microsporidia was found in wild waterfowl which was 54.5% (28.1-78.6). In terms of detection methods, the pooled prevalence was estimated to be 21.2% (95% CI: 12.1-34.4) and 13.4% (95% CI: 10.3-17.3) for using microscopic and molecular detection methods, respectively. Enterocytozoon bieneusi was the most common pathogen (24/31; 77.42% of the studies) according to PCR-based methods, and genotype D was the highest reported genotype (nine studies). In conclusion, designing strategies for the control and prevention of Microsporidia infection in birds should be recommended.

Genetic diversity of Cryptosporidium spp., Encephalitozoon spp. and Enterocytozoon bieneusi in feral and captive pigeons in Central Europe

Cryptosporidium spp., Enterocytozoon bieneusi and Encephalitozoon spp. are the most common protistan parasites of vertebrates. The results show that pigeon populations in Central Europe are parasitised by different species of Cryptosporidium and genotypes of microsporidia of the genera Enterocytozoon and Encephalitozoon. A total of 634 and 306 faecal samples of captive and feral pigeons (Columba livia f. domestica) from 44 locations in the Czech Republic, Slovakia and Poland were analysed for the presence of parasites by microscopy and PCR/sequence analysis of small subunit ribosomal RNA (18S rDNA), 60 kDa glycoprotein (gp60) and internal transcribed spacer (ITS) of SSU rDNA. Phylogenetic analyses revealed the presence of C. meleagridis, C. baileyi, C. parvum, C. andersoni, C. muris, C. galli and C. ornithophilus, E. hellem genotype 1A and 2B, E. cuniculi genotype I and II and E. bieneusi genotype Peru 6, CHN-F1, D, Peru 8, Type IV, ZY37, E, CHN4, SCF2 and WR4. Captive pigeons were significantly more frequently parasitised with screened parasite than feral pigeons. Cryptosporidium meleagridis IIIa and a new subtype IIIl have been described, the oocysts of which are not infectious to immunodeficient mice, whereas chickens are susceptible. This investigation demonstrates that pigeons can be hosts to numerous species, genotypes and subtypes of the studied parasites. Consequently, they represent a potential source of infection for both livestock and humans.

Molecular detection and prevalence of human-pathologic Enterocytozoon bieneusi among pet birds in Mosul, Iraq

Enterocytozoon bieneusi has been classified as an emerging infectious organism (microsporidium) due to the global increase in the number of cases infecting both humans and animals. The goal of this study was to use the polymerase chain reaction method to determine the prevalence and risk factors associated with E. bieneusi infection among pet birds in Mosul, Iraq. Faecal samples from a total of six hundred and twenty-eight pet birds belonging to fifteen (15) different species were analyzed by targeting the internal transcribed spacer (ITS) of the rRNA gene. Of the total number of pet birds sampled, 203 tested positive for the parasite, representing 32.32% (95% CI = 28.75-36.06) of the sampled population. There was a significant difference (p < 0.01) in the prevalence of E. bieneusi infection among the different species of pet birds, with the highest prevalence recorded among Eurasian bullfinches (Pyrrhula pyrrhula) (64.06%; 95% CI = 55.48-72.02), budgerigars (Melopsittacus undulatus) (48.72%; 95% CI = 40.93-56.55), Fischer's lovebirds (Agapornis fischeri) (25.00%; 95% CI = 13.45-40.05), and macaws parrots (Ara ararauna) (25.00%; 95% CI = 1.25-75.77). The order, source, and health status of pet birds were significantly (p < 0.05) associated with the prevalence of E. bieneusi infection among pet birds in Mosul, Iraq. In conclusion, the level of prevalence of E. bieneusi among pet birds may increase the risk of infection for owners of pet birds in Iraq.

Occurrence and molecular characterization of Enterocytozoon bieneusi in water buffaloes (Bubalus bubalis) in Turkey

Microsporidia are obligate intracellular fungus-like parasites that infect humans and animals worldwide. However, there is limited epidemiological data on the occurrence and molecular diversity of microsporidia in buffaloes worldwide. In the present study, fecal samples of 300 water buffaloes (Bubalus bubalis) in Kayseri, Sivas, and Samsun provinces of Turkey were investigated using two nested PCR assays targeting the rRNA of E. bieneusi and Encephalitozoon spp. All the fecal samples from water buffalo were found to be negative for Encephalitozoon spp. PCR positive isolates of E. bieneusi were bidirectionally sequenced for genotyping and phylogenetic analyses. Enterocytozoon bieneusi was the only microsporidian species identified in 8 water buffaloes with an overall molecular prevalence of 2.7%. Two known genotypes, YNDCEB-90 (n = 5) and J (n = 3) were identified by ITS sequence analysis. The YNDCEB-90 and J genotypes fall into zoonotic Group 1 and 2 of E. bieneusi in the phylogenetic tree, respectively. These findings suggested that water buffalo in Turkey are harbouring zoonotic genotypes of E. bieneusi and may have a significant risk for zoonotic transmission to humans. This is the first report of detecting E. bieneusi genotypes J and YNDCEB-90 in water buffaloes. Further insight into the epidemiology of E. bieneusi in water buffaloes in different geographical areas in Turkey will be highly important to have determined the public health significance of this pathogen.

Global prevalence of zoonotic pathogens from pigeon birds: A systematic review and meta-analysis

Pigeons have been considered the most preferred companion for human civilizations since prehistoric times. Despite the fact that pigeons offer the most palatable and nutritious food and provide pleasure to humans, they can pose a health risk because of carrying infectious and zoonotic organisms. Moreover, the scanty of systematic reports on the occurrence of zoonotic pathogens in pigeon makes the situations worst. Hence, the current study conducted a systematic review and meta-analysis to evaluate the global prevalence of zoonotic pathogens among the pigeon population from existing segregated literatures. Four internationally recognized databases including Google Scholar, Scopus, PubMed, and Science Direct were used to search the published studies from January 2000 to October 2021. Analyzing the total 18,589 samples, mean prevalence estimates of pigeon pathogens worldwide were found to be 17% (95% CI:13-21) whereas serological and molecular prevalence were reported as 18% (95% CI:12-23) and 17% (95% CI:10-23). Meanwhile, virus, bacteria, and protozoal pathogens were found to be 21% (10-32%), 17% (12-23%), and 14% (10-19%), respectively. Moreover, continent wise analysis of all zoonotic pigeon pathogens has revealed the highest prevalence rate in Asia 20% (95% CI: 14-26%), followed by Europe 16% (95% CI: 08-24%), Africa 16% (95% CI: 07-24%), and America (North and South) 10% (95% CI: 03-17%). Furthermore, the highest number of studies were reported from Iran showed the prevalence rate of 20%, China 13%, Bangladesh 37%, and Poland 15%. Therefore, this prevalence of data would be helpful to the policymakers to develop appropriate intervention strategies to prevent and control diseases in their respective locations.

A Perspective on the Molecular Identification, Classification, and Epidemiology of Enterocytozoon bieneusi of Animals

The microsporidian Enterocytozoon bieneusi is an obligate intracellular pathogen that causes enteric disease (microsporidiosis) in humans and has been recorded in a wide range of animal species worldwide. The transmission of E. bieneusi is direct and likely occurs from person to person and from animal to person via the ingestion of spores in water, food, or the environment. The identification of E. bieneusi is usually accomplished by molecular means, typically using the sequence of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. Currently, ~820 distinct genotypes of E. bieneusi have been recorded in at least 210 species of vertebrates (mammals, birds, reptiles, and amphibians) or invertebrates (insects and mussels) in more than 50 countries. In this chapter, we provide a perspective on (1) clinical aspects of human microsporidiosis; (2) the genome and DNA markers for E. bieneusi as well as molecular methods for the specific and genotypic identification of E. bieneusi; (3) epidemiological aspects of E. bieneusi of animals and humans, with an emphasis on the genotypes proposed to be zoonotic, human-specific, and animal-specific; and (4) future research directions to underpin expanded molecular studies to better understand E. bieneusi and microsporidiosis.

First genotyping of Enterocytozoon bieneusi in plateau pikas (Ochotona curzoniae) from the Qinghai Plateau, Northwest China

Enterocytozoon bieneusi is considered the most common microsporidian species and is frequently detected in humans and various animals worldwide. However, information on E. bieneusi infection in plateau pikas (Ochotona curzoniae) is somewhat limited. Therefore, this study was conducted to determine the infection status and genotype characteristics of E. bieneusi in plateau pikas in China. A total of 33 fresh fecal samples were collected from plateau pikas captured on the Qinghai Plateau. By PCR assay and DNA sequencing of the ITS gene, 5 (15.2%, 5/33) isolates were diagnosed as positive. Sequence analysis revealed the presence of one known sheep-derived genotype, CHS17 (4/5), and a novel E. bieneusi genotype, CHPP1 (1/5), with maximum shared identity with the CHS17 genotype. Phylogenetically, these isolates were clustered into subgroup 1i of zoonotic group 1 with genotypes CHS17 and CHN14 from plateau ruminants, but the new CHP1 genotype formed a cluster separate from those genotypes. This is the first report of E. bieneusi in plateau pikas. The findings suggested that these animals might be potential reservoirs of zoonotic E. bieneusi, and transmission of the pathogen between plateau pikas and sheep probably occurs in the region.

Survey on the Presence of Bacterial and Parasitic Zoonotic Agents in the Feces of Wild Birds

Wild avifauna may act as fecal source of bacterial and parasitic pathogens for other birds and mammals. Most of these pathogens have a relevant impact on human and livestock health which may cause severe disease and economic loss. In the present study, the fecal samples collected from 121 wild birds belonging to 15 species of the genera Anas, Tadorna, Fulica, Arddea, Larus, Falco, Athene, Accipiter, and Columba were submitted to bacteriological and molecular analyses to detect Brucella spp., Coxiella burnetii, Mycobacterium spp., Salmonella spp., Cryptosporidium spp., Giardia spp., and microsporidia. Four (3.3%) animals were positive for one pathogen: one Anas penelope for C. burnetii, one Larus michahellis for S. enterica serovar Coeln, and two Columba livia for Encephalitozoon hellem. Although the prevalence rates found in the present survey were quite low, the obtained results confirm that wild birds would be the a potential fecal source of bacterial and parasitic zoonotic pathogens which sometimes can also represent a severe threat for farm animals.