Parasitic Intestinal Protists of Zoonotic Relevance Detected in Pigs by Metabarcoding and Real-Time PCR
Status PubMed-not-MEDLINE Jazyk angličtina Země Švýcarsko Médium electronic
Typ dokumentu časopisecké články
Grantová podpora
773830
Horizon 2020
PubMed
34073014
PubMed Central
PMC8229027
DOI
10.3390/microorganisms9061189
PII: microorganisms9061189
Knihovny.cz E-zdroje
- Klíčová slova
- DNA, PCR, genetic diversity, host specificity, metabarcoding, next-generation sequencing, parasite, parasitology, zoonotic infections,
- Publikační typ
- časopisecké články MeSH
Several parasite species are shared between humans and pigs. We explored the application of next-generation sequencing-based metabarcoding supplemented with real-time PCR to fecal DNAs from 259 samples from 116 pigs in Denmark to detect and differentiate single-celled intestinal parasites of zoonotic relevance. Enterocytozoon bieneusi, Balantioides coli, and Giardia duodenalis were observed in 34/37 (92%), 148/259 (57%), and 86/259 (33%) samples, respectively. Entamoeba polecki ST1, E. polecki ST3, and Entamoeba hartmanni were detected in 104/259 (40%), 161/259 (62%), and 8/259 (3%) samples, respectively. Metabarcoding and real-time PCR detected Cryptosporidium in 90/259 (35%) and 239/259 (92%) of the samples, respectively, with Cryptosporidium suis and Cryptosporidium scrofarum observed in nearly equal proportions. Blastocystis subtypes 1, 3, 5, and 15 were found in 72 (28%), 6 (2%), 176 (68%), and 36 (14%) of 259 samples, respectively. Iodamoeba was identified in 1/259 samples (<1%), while none of 37 tested samples was positive for Dientamoeba fragilis. Our results illustrate how metabarcoding exemplifies a 'one-fits-many' approach to detecting intestinal single-celled parasites in feces supplemented with real-time PCR for selected parasites. Using metabarcoding with pathogen-specific assays may help detect emerging and previously underdetected pathogens and further elucidate the role of micro-eukaryotic parasites in human and animal health and disease.
Zobrazit více v PubMed
Robertson L.J., Lalle M., Paulsen P. Why we need a European focus on foodborne parasites. Exp. Parasitol. 2020;214:107900. doi: 10.1016/j.exppara.2020.107900. PubMed DOI
Lhotská Z., Jirků M., Hložková O., Brožová K., Jirsová D., Stensvold C.R., Kolísko M., Jirků Pomajbíková K. A Study on the Prevalence and Subtype Diversity of the Intestinal Protist Blastocystis sp. in a Gut-Healthy Human Population in the Czech Republic. Front. Cell Infect. Microbiol. 2020;10:544335. doi: 10.3389/fcimb.2020.544335. PubMed DOI PMC
Schuster F.L., Ramirez-Avila L. Current world status of Balantidium coli. Clin. Microbiol. Rev. 2008;21:626–638. doi: 10.1128/CMR.00021-08. PubMed DOI PMC
Pomajbikova K., Obornik M., Horak A., Petrzelkova K.J., Grim J.N., Levecke B., Todd A., Mulama M., Kiyang J., Modry D. Novel insights into the genetic diversity of Balantidium and Balantidium-like cyst-forming ciliates. PLoS Negl. Trop. Dis. 2013;7:e2140. doi: 10.1371/journal.pntd.0002140. PubMed DOI PMC
Cacciò S.M., Sannella A.R., Manuali E., Tosini F., Sensi M., Crotti D., Pozio E. Pigs as natural hosts of Dientamoeba fragilis genotypes found in humans. Emerg. Infect. Dis. 2012;18:838–841. doi: 10.3201/eid1805.111093. PubMed DOI PMC
Ahmed A., Ijaz M., Ayyub R.M., Ghaffar A., Ghauri H.N., Aziz M.U., Ali S., Altaf M., Awais M., Naveed M., et al. Balantidium coli in domestic animals: An emerging protozoan pathogen of zoonotic significance. Acta Trop. 2020;203:105298. doi: 10.1016/j.actatropica.2019.105298. PubMed DOI
Clark C.G., Kaffashian F., Tawari B., Windsor J.J., Twigg-Flesner A., Davies-Morel M.C., Blessmann J., Ebert F., Peschel B., Le Van A., et al. New insights into the phylogeny of Entamoeba species provided by analysis of four new small-subunit rRNA genes. Int. J. Syst. Evol. Microbiol. 2006;56:2235–2239. doi: 10.1099/ijs.0.64208-0. PubMed DOI
Dashti A., Rivero-Juarez A., Santin M., Lopez-Lopez P., Caballero-Gomez J., Frias-Casas M., Koster P.C., Bailo B., Calero-Bernal R., Briz V., et al. 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. Kransbound. Emerg. Dis. 2020;67:2869–2880. doi: 10.1111/tbed.13658. PubMed DOI
Li W., Feng Y., Xiao L. Diagnosis and molecular typing of Enterocytozoon bieneusi: The significant role of domestic animals in transmission of human microsporidiosis. Res. Vet. Sci. 2020;133:251–261. doi: 10.1016/j.rvsc.2020.09.030. PubMed DOI
Verweij J.J., Stensvold C.R. Molecular Testing for Clinical Diagnosis and Epidemiological Investigations of Intestinal Parasitic Infections. Clin. Microbiol. Rev. 2014;27:371–418. doi: 10.1128/CMR.00122-13. PubMed DOI PMC
FAO . FAO Animal Health Manual. FAO; Rome, Italy: 1998. Epidemiology, diagnosis and control of helminth parasites of swine.
Krogsgaard L.R., Andersen L.O., Johannesen T.B., Engsbro A.L., Stensvold C.R., Nielsen H.V., Bytzer P. Characteristics of the bacterial microbiome in association with common intestinal parasites in irritable bowel syndrome. Clin. Transl. Gastroenterol. 2018;9:161. doi: 10.1038/s41424-018-0027-2. PubMed DOI PMC
Ring H.C., Thorsen J., Saunte D.M., Lilje B., Bay L., Riis P.T., Larsen N., Andersen L.O., Nielsen H.V., Miller I.M., et al. The Follicular Skin Microbiome in Patients With Hidradenitis Suppurativa and Healthy Controls. JAMA Dermatol. 2017;153:897–905. doi: 10.1001/jamadermatol.2017.0904. PubMed DOI PMC
Holmgaard D.B., Barnadas C., Mirbarati S.H., Andersen L.O., Nielsen H.V., Stensvold C.R. Detection and identification of Acanthamoeba and other non-viral causes of infectious keratitis in corneal scrapings by real-time PCR and next-generation sequencing-based 16S-18S gene analysis. J. Clin. Microbiol. 2020;59 doi: 10.1128/JCM.02224-20. PubMed DOI PMC
Stensvold C.R., Lebbad M., Hansen A., Beser J., Belkessa S., O’Brien Andersen L., Clark C.G. Differentiation of Blastocystis and parasitic archamoebids encountered in untreated wastewater samples by amplicon-based next-generation sequencing. Parasite Epidemiol. Control. 2020;9:e00131. doi: 10.1016/j.parepi.2019.e00131. PubMed DOI PMC
Wylezich C., Belka A., Hanke D., Beer M., Blome S., Höper D. Metagenomics for broad and improved parasite detection: A proof-of-concept study using swine faecal samples. Int. J. Parasitol. 2019;49:769–777. doi: 10.1016/j.ijpara.2019.04.007. PubMed DOI
Ramayo-Caldas Y., Prenafeta-Boldu F., Zingaretti L.M., Gonzalez-Rodriguez O., Dalmau A., Quintanilla R., Ballester M. Gut eukaryotic communities in pigs: Diversity, composition and host genetics contribution. Anim. Microbiome. 2020;2:18. doi: 10.1186/s42523-020-00038-4. PubMed DOI PMC
Græsbøll K., Damborg P., Mellerup A., Herrero-Fresno A., Larsen I., Holm A., Nielsen J.P., Christiansen L.E., Angen Ø., Ahmed S., et al. Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs. Appl. Environ. Microbiol. 2017;83 doi: 10.1128/AEM.00538-17. PubMed DOI PMC
Græsbøll K., Larsen I., Clasen J., Birkegård A.C., Nielsen J.P., Christiansen L.E., Olsen J.E., Angen Ø., Folkesson A. Effect of tetracycline treatment regimens on antibiotic resistance gene selection over time in nursery pigs. BMC Microbiol. 2019;19:269. doi: 10.1186/s12866-019-1619-z. PubMed DOI PMC
Larsen I., Hjulsager C.K., Holm A., Olsen J.E., Nielsen S.S., Nielsen J.P. A randomised clinical trial on the efficacy of oxytetracycline dose through water medication of nursery pigs on diarrhoea, faecal shedding of Lawsonia intracellularis and average daily weight gain. Prev. Vet. Med. 2016;123:52–59. doi: 10.1016/j.prevetmed.2015.12.004. PubMed DOI
Larsen I., Nielsen S.S., Olsen J.E., Nielsen J.P. The efficacy of oxytetracycline treatment at batch, pen and individual level on Lawsonia intracellularis infection in nursery pigs in a randomised clinical trial. Prev. Vet. Med. 2016;124:25–33. doi: 10.1016/j.prevetmed.2015.12.018. PubMed DOI
Fredensborg B.L., Fossdal í Kálvalíð I., Johannesen T.B., Stensvold C.R., Nielsen H.V., Kapel C.M.O. Parasites modulate the gut-microbiome in insects: A proof-of-concept study. PLoS ONE. 2020;15:e0227561. doi: 10.1371/journal.pone.0227561. PubMed DOI PMC
Thomas-Lopez D., Muller L., Vestergaard L.S., Christoffersen M., Andersen A.M., Jokelainen P., Agerholm J.S., Stensvold C.R. Veterinary Students Have a Higher Risk of Contracting Cryptosporidiosis when Calves with High Fecal Cryptosporidium Loads Are Used for Fetotomy Exercises. Appl. Environ. Microbiol. 2020;86 doi: 10.1128/AEM.01250-20. PubMed DOI PMC
Verweij J.J., Mulder B., Poell B., van Middelkoop D., Brienen E.A., van Lieshout L. Real-time PCR for the detection of Dientamoeba fragilis in fecal samples. Mol. Cell. Probes. 2007;21:400–404. doi: 10.1016/j.mcp.2007.05.006. PubMed DOI
Verweij J.J., Ten Hove R., Brienen E.A., van Lieshout L. Multiplex detection of Enterocytozoon bieneusi and Encephalitozoon spp. in fecal samples using real-time PCR. Diagn. Microbiol. Infect. Dis. 2007;57:163–167. doi: 10.1016/j.diagmicrobio.2006.08.009. PubMed DOI
Xiao L., Escalante L., Yang C., Sulaiman I., Escalante A.A., Montali R.J., Fayer R., Lal A.A. Phylogenetic analysis of Cryptosporidium parasites based on the small-subunit rRNA gene locus. Appl. Environ. Microbiol. 1999;65:1578–1583. doi: 10.1128/AEM.65.4.1578-1583.1999. PubMed DOI PMC
Buckholt M.A., Lee J.H., Tzipori S. Prevalence of Enterocytozoon bieneusi in swine: An 18-month survey at a slaughterhouse in Massachusetts. Appl. Environ. Microbiol. 2002;68:2595–2599. doi: 10.1128/AEM.68.5.2595-2599.2002. PubMed DOI PMC
Verweij J.J., Schinkel J., Laeijendecker D., van Rooyen M.A., van Lieshout L., Polderman A.M. Real-time PCR for the detection of Giardia lamblia. Mol. Cell Probes. 2003;17:223–225. doi: 10.1016/S0890-8508(03)00057-4. PubMed DOI
Morgan U.M., Monis P.T., Fayer R., Deplazes P., Thompson R.C. Phylogenetic relationships among isolates of Cryptosporidium: Evidence for several new species. J. Parasitol. 1999;85:1126–1133. doi: 10.2307/3285678. PubMed DOI
Kváč M., Kestřánová M., Pinková M., Květoňová D., Kalinová J., Wagnerová P., Kotková M., Vítovec J., Ditrich O., McEvoy J., et al. Cryptosporidium scrofarum n. sp. (Apicomplexa: Cryptosporidiidae) in domestic pigs (Sus scrofa) Vet. Parasitol. 2013;191:218–227. doi: 10.1016/j.vetpar.2012.09.005. PubMed DOI PMC
Stensvold C.R., Lebbad M., Victory E.L., Verweij J.J., Tannich E., Alfellani M., Legarraga P., Clark C.G. Increased sampling reveals novel lineages of Entamoeba: Consequences of genetic diversity and host specificity for taxonomy and molecular detection. Protist. 2011;162:525–541. doi: 10.1016/j.protis.2010.11.002. PubMed DOI
Nilles-Bije M.L., Rivera W.L. Ultrastructural and molecular characterization of Balantidium coli isolated in the Philippines. Parasitol. Res. 2010;106:387–394. doi: 10.1007/s00436-009-1673-9. PubMed DOI
Stolzenbach S., Myhill L.J., Andersen L.O., Krych L., Mejer H., Williams A.R., Nejsum P., Stensvold C.R., Nielsen D.S., Thamsborg S.M. Dietary Inulin and Trichuris suis Infection Promote Beneficial Bacteria Throughout the Porcine Gut. Front. Microbiol. 2020;11:312. doi: 10.3389/fmicb.2020.00312. PubMed DOI PMC
Stensvold C.R., O’Brien Andersen L., Jokelainen P. Protocol for 18S rDNA-based amplicon sequencing for detection of relevant Foodborne Parasites. Zenodo. 2021 doi: 10.5281/zenodo.4478998. DOI
Stensvold C.R., Winiecka-Krusnell J., Lier T., Lebbad M. Evaluation of a PCR Method for Detection of Entamoeba polecki, with an Overview of Its Molecular Epidemiology. J. Clin. Microbiol. 2018;56 doi: 10.1128/JCM.00154-18. PubMed DOI PMC
Xiao L., Feng Y. Molecular epidemiologic tools for waterborne pathogens Cryptosporidium spp. and Giardia duodenalis. Food Waterborne Parasitol. 2017;8–9:14–32. doi: 10.1016/j.fawpar.2017.09.002. PubMed DOI PMC
Kvac M., Kvetonova D., Sak B., Ditrich O. Cryptosporidium pig genotype II in immunocompetent man. Emerg. Infect. Dis. 2009;15:982–983. doi: 10.3201/eid1506.071621. PubMed DOI PMC
Wylezich C., Caccio S.M., Walochnik J., Beer M., Höper D. Untargeted metagenomics shows a reliable performance for synchronous detection of parasites. Parasitol. Res. 2020;119:2623–2629. doi: 10.1007/s00436-020-06754-9. PubMed DOI PMC
Parfrey L.W., Walters W.A., Lauber C.L., Clemente J.C., Berg-Lyons D., Teiling C., Kodira C., Mohiuddin M., Brunelle J., Driscoll M., et al. Communities of microbial eukaryotes in the mammalian gut within the context of environmental eukaryotic diversity. Front. Microbiol. 2014;5:298. doi: 10.3389/fmicb.2014.00298. PubMed DOI PMC
Pettersson E., Ahola H., Frossling J., Wallgren P., Troell K. Detection and molecular characterisation of Cryptosporidium spp. in Swedish pigs. Acta Vet. Scand. 2020;62:40. doi: 10.1186/s13028-020-00537-z. PubMed DOI PMC
Langkjaer R.B., Vigre H., Enemark H.L., Maddox-Hyttel C. Molecular and phylogenetic characterization of Cryptosporidium and Giardia from pigs and cattle in Denmark. Parasitology. 2007;134:339–350. doi: 10.1017/S0031182006001533. PubMed DOI
Petersen H.H., Jianmin W., Katakam K.K., Mejer H., Thamsborg S.M., Dalsgaard A., Olsen A., Enemark H.L. Cryptosporidium and Giardia in Danish organic pig farms: Seasonal and age-related variation in prevalence, infection intensity and species/genotypes. Vet. Parasitol. 2015;214:29–39. doi: 10.1016/j.vetpar.2015.09.020. PubMed DOI
Sak B., Kvác M., Hanzlíková D., Cama V. First report of Enterocytozoon bieneusi infection on a pig farm in the Czech Republic. Vet. Parasitol. 2008;153:220–224. doi: 10.1016/j.vetpar.2008.01.043. PubMed DOI
Decraene V., Lebbad M., Botero-Kleiven S., Gustavsson A.M., Löfdahl M. First reported foodborne outbreak associated with microsporidia, Sweden, October 2009. Epidemiol. Infect. 2012;140:519–527. doi: 10.1017/S095026881100077X. PubMed DOI PMC
Li W., Feng Y., Santin M. Host Specificity of Enterocytozoon bieneusi and Public Health Implications. Trends Parasitol. 2019;35:436–451. doi: 10.1016/j.pt.2019.04.004. PubMed DOI
Jokelainen P., Hebbelstrup Jensen B., Andreassen B.U., Petersen A.M., Röser D., Krogfelt K.A., Nielsen H.V., Stensvold C.R. Dientamoeba fragilis—A Commensal in Children in Danish Day Care Centers. J. Clin. Microbiol. 2017;55:1707–1713. doi: 10.1128/JCM.00037-17. PubMed DOI PMC
Roser D., Simonsen J., Nielsen H.V., Stensvold C.R., Molbak K. Dientamoeba fragilis in Denmark: Epidemiological experience derived from four years of routine real-time PCR. Eur. J. Clin. Microbiol. Infect. Dis. 2013;32:1303–1310. doi: 10.1007/s10096-013-1880-2. PubMed DOI
Crotti D., Sensi M., Crotti S., Grelloni V., Manuali E. Dientamoeba fragilis in swine population: A preliminary investigation. Vet. Parasitol. 2007;145:349–351. doi: 10.1016/j.vetpar.2007.01.006. PubMed DOI
Krogsgaard L.R., Engsbro A.L., Stensvold C.R., Nielsen H.V., Bytzer P. The prevalence of intestinal parasites is not greater among individuals with irritable bowel syndrome: A population-based case-control study. Clin. Gastroenterol. Hepatol. 2015;13:507–513.e502. doi: 10.1016/j.cgh.2014.07.065. PubMed DOI
Andersen L.O., Bonde I., Nielsen H.B., Stensvold C.R. A retrospective metagenomics approach to studying Blastocystis. FEMS Microbiol. Ecol. 2015;91 doi: 10.1093/femsec/fiv072. PubMed DOI
Stensvold C.R., Alfellani M.A., Nørskov-Lauritsen S., Prip K., Victory E.L., Maddox C., Nielsen H.V., Clark C.G. Subtype distribution of Blastocystis isolates from synanthropic and zoo animals and identification of a new subtype. Int. J. Parasitol. 2009;39:473–479. doi: 10.1016/j.ijpara.2008.07.006. PubMed DOI
Navarro C., Domínguez-Márquez M.V., Garijo-Toledo M.M., Vega-García S., Fernández-Barredo S., Pérez-Gracia M.T., García A., Borrás R., Gómez-Muñoz M.T. High prevalence of Blastocystis sp. in pigs reared under intensive growing systems: Frequency of ribotypes and associated risk factors. Vet. Parasitol. 2008;153:347–358. doi: 10.1016/j.vetpar.2008.02.003. PubMed DOI
Thathaisong U., Worapong J., Mungthin M., Tan-Ariya P., Viputtigul K., Sudatis A., Noonai A., Leelayoova S. Blastocystis isolates from a pig and a horse are closely related to Blastocystis hominis. J. Clin. Microbiol. 2003;41:967–975. doi: 10.1128/JCM.41.3.967-975.2003. PubMed DOI PMC
Tan T.C., Tan P.C., Sharma R., Sugnaseelan S., Suresh K.G. Genetic diversity of caprine Blastocystis from Peninsular Malaysia. Parasitol. Res. 2013;112:85–89. doi: 10.1007/s00436-012-3107-3. PubMed DOI
Rauff-Adedotun A.A., Mohd Zain S.N., Farah Haziqah M.T. Current status of Blastocystis sp. in animals from Southeast Asia: A review. Parasitol. Res. 2020;119:3559–3570. doi: 10.1007/s00436-020-06828-8. PubMed DOI PMC
Danisova O., Valencakova A. First detection of Blastocystis sp. in pigs in Slovakia and in Europe. Parasitol. Int. 2020;81:102235. doi: 10.1016/j.parint.2020.102235. PubMed DOI
Jimenez P.A., Jaimes J.E., Ramirez J.D. A summary of Blastocystis subtypes in North and South America. Parasit. Vectors. 2019;12:376. doi: 10.1186/s13071-019-3641-2. PubMed DOI PMC
Stensvold C.R., Alfellani M., Clark C.G. Levels of genetic diversity vary dramatically between Blastocystis subtypes. Infect. Genet. Evol. 2012;12:263–273. doi: 10.1016/j.meegid.2011.11.002. PubMed DOI
Alfellani M.A., Taner-Mulla D., Jacob A.S., Imeede C.A., Yoshikawa H., Stensvold C.R., Clark C.G. Genetic diversity of Blastocystis in livestock and zoo animals. Protist. 2013;164:497–509. doi: 10.1016/j.protis.2013.05.003. PubMed DOI
Russini V., Di Filippo M.M., Fanelli R., Polidori M., Berrilli F., Di Cave D., Novelletto A., Calderini P. Characterization of prevalence and genetic subtypes of Blastocystis sp. in wild and domestic Suidae of central Italy aided by amplicon NGS. Vet. Parasitol. Reg. Stud. Rep. 2020;22:100472. doi: 10.1016/j.vprsr.2020.100472. PubMed DOI
Burrows R.B. Morphological differentiation of Entamoeba hartmanni and E. polecki from E. histolytica. Am. J. Trop. Med. Hyg. 1959;8:583–589. doi: 10.4269/ajtmh.1959.8.583. PubMed DOI
Burrows R.B. Microscopic Diagnosis of the Parasites of Man. Yale University Press; New Haven, CT, USA: 1965. pp. 118–119.
Li W.C., Geng J.Z., Chen C., Qian L., Zhang T., Liu J.L., Luo J.X., Gu Y.F. First report on the occurance of intestinal Entamoeba spp. in pigs in China. Acta Trop. 2018;185:385–390. doi: 10.1016/j.actatropica.2018.06.020. PubMed DOI
Verweij J.J., Polderman A.M., Clark C.G. Genetic Variation among Human Isolates of Uninucleated Cyst-Producing Entamoeba Species. J. Clin. Microbiol. 2001;39:1644–1646. doi: 10.1128/JCM.39.4.1644-1646.2001. PubMed DOI PMC
Ji T., Cao H.X., Wu R., Cui L.L., Su G.M., Niu C., Zhang N., Wang S.K., Zhou D.H. Prevalence and Genetic Identification of Three Entamoeba Species in Pigs in Southeastern China. Biomed Res. Int. 2019:2824017. doi: 10.1155/2019/2824017. PubMed DOI PMC
Wardhana A.H., Sawitri D.H., Ekawasti F., Martindah E., Apritadewi D., Shibahara T., Kusumoto M., Tokoro M., Sasai K., Matsubayashi M. Occurrence and genetic identifications of porcine Entamoeba, E. suis and E. polecki, at Tangerang in West Java, Indonesia. Parasitol. Res. 2020;119:2983–2990. doi: 10.1007/s00436-020-06806-0. PubMed DOI
Schubnell F., von Ah S., Graage R., Sydler T., Sidler X., Hadorn D., Basso W. Occurrence, clinical involvement and zoonotic potential of endoparasites infecting Swiss pigs. Parasitol. Int. 2016;65:618–624. doi: 10.1016/j.parint.2016.09.005. PubMed DOI PMC
Roesel K., Dohoo I., Baumann M., Dione M., Grace D., Clausen P.H. Prevalence and risk factors for gastrointestinal parasites in small-scale pig enterprises in Central and Eastern Uganda. Parasitol. Res. 2017;116:335–345. doi: 10.1007/s00436-016-5296-7. PubMed DOI PMC
Da Silva Barbosa A., Ponce-Gordo F., Dib L.V., Antunes Uchoa C.M., Bastos O.M.P., Pissinatti A., Amendoeira M.R.R. First molecular characterization of Balantioides coli (Malmsten, 1857) isolates maintained in vitro culture and from feces of captive animals, Rio de Janeiro, Brazil. Vet. Parasitol. Reg. Stud. Rep. 2017;10:102–113. doi: 10.1016/j.vprsr.2017.08.014. PubMed DOI
Li Y.H., Yao Q., Dong H.P., Wang S.S., Chen R.R., Song J.K., Yan W.C., Zhao G.H. Molecular characterization of Balantioides coli in pigs from Shaanxi province, northwestern China. Parasitol. Res. 2020;119:3075–3081. doi: 10.1007/s00436-020-06800-6. PubMed DOI
Ponce-Gordo F., Fonseca-Salamanca F., Martinez-Diaz R.A. Genetic heterogeneity in internal transcribed spacer genes of Balantidium coli (Litostomatea, Ciliophora) Protist. 2011;162:774–794. doi: 10.1016/j.protis.2011.06.008. PubMed DOI
Lopez Arias L., Guillemi E., Bordoni N., Farber M., Garbossa G. Development of a PCR assay for identification of Neobalantidium coli () in Argentina. Vet. Parasitol. Reg. Stud. Rep. 2017;10:114–118. doi: 10.1016/j.vprsr.2017.08.010. PubMed DOI
Stensvold C.R., Lebbad M., Clark C.G. Last of the human protists: The phylogeny and genetic diversity of Iodamoeba. Mol. Biol Evol. 2012;29:39–42. doi: 10.1093/molbev/msr238. PubMed DOI