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Jones BP, Kozel K, Alonte AJI, Llanes KKR, Juhász A, Chaudhry U, Roose S, Geldhof P, Belizario VY, Nejsum P, Stothard JR, LaCourse EJ, van Vliet AHM, Paller VGV, Betson M. Worldwide absence of canonical benzimidazole resistance-associated mutations within β-tubulin genes from Ascaris. Parasit Vectors 2024; 17:225. [PMID: 38755679 PMCID: PMC11098727 DOI: 10.1186/s13071-024-06306-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/24/2024] [Indexed: 05/18/2024] Open
Abstract
BACKGROUND The giant roundworm Ascaris is an intestinal nematode, causing ascariasis by infecting humans and pigs worldwide. Recent estimates suggest that Ascaris infects over half a billion people, with chronic infections leading to reduced growth and cognitive ability. Ascariasis affects innumerable pigs worldwide and is known to reduce production yields via decreased growth and condemnation of livers. The predominant anthelminthic drugs used to treat ascariasis are the benzimidazoles. Benzimidazoles interact with β-tubulins and block their function, and several benzimidazole resistance-associated mutations have been described in the β-tubulins of ruminant nematodes. Recent research on ascarids has shown that these canonical benzimidazole resistance-associated mutations are likely not present in the β-tubulins of Ascaris, Ascaridia or Parascaris, even in phenotypically resistant populations. METHODS To further determine the putative absence of key β-tubulin polymorphisms, we screened two β-tubulin isotypes of Ascaris, highly expressed in adult worms. Using adult and egg samples of Ascaris obtained from pigs and humans worldwide, we performed deep amplicon sequencing to look for canonical resistance-associated mutations in Ascaris β-tubulins. Subsequently, we examined these data in closer detail to study the population dynamics of Ascaris and genetic diversity within the two isotypes and tested whether genotypes appeared to partition across human and pig hosts. RESULTS In the 187 isolates, 69 genotypes were found, made up of eight haplotypes of β-tubulin isotype A and 20 haplotypes of isotype B. Single nucleotide polymorphisms were seen at 14 and 37 positions for β-tubulin isotype A and isotype B, respectively. No evidence of any canonical benzimidazole resistance-associated mutations was found in either human- or pig-derived Ascaris isolates. There was, however, a difference in the genetic diversity of each isotype and distribution of β-tubulin genotypes between human- and pig-derived Ascaris. Statistical tests of population differentiation show significant differences (p < 0.001) between pig- and human-derived worms; however, more diversity was seen between worms from different populations than worms from different hosts. CONCLUSIONS Our work suggests an absence of canonical β-tubulin mutations within Ascaris, but alternative modes of anthelminthic resistance may emerge necessitating continued genetic scrutiny alongside monitoring of drug efficacy.
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Affiliation(s)
- Ben P Jones
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK
| | - Kezia Kozel
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK
| | - Allen Jethro I Alonte
- Institute of Biological Sciences, University of the Philippines Los Baños, Laguna, Philippines
| | - Kennesa Klariz R Llanes
- Institute of Biological Sciences, University of the Philippines Los Baños, Laguna, Philippines
| | - Alexandra Juhász
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Institute of Medical Microbiology, Semmelweis University, Budapest, Hungary
| | - Umer Chaudhry
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK
- School of Veterinary Medicine, St. George's University, True Blue, West Indies, Grenada
| | - Sara Roose
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Peter Geldhof
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Vicente Y Belizario
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Manila, Philippines
| | - Peter Nejsum
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - E James LaCourse
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Arnoud H M van Vliet
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK
| | - Vachel Gay V Paller
- Institute of Biological Sciences, University of the Philippines Los Baños, Laguna, Philippines
| | - Martha Betson
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK.
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Agustina KK, Wirawan IMA, Sudarmaja IM, Subrata IM, Dharmawan NS. Ascaris suum - A zoonosis in Bali, Indonesia. Trop Parasitol 2023; 13:100-106. [PMID: 37860613 PMCID: PMC10583779 DOI: 10.4103/tp.tp_24_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/28/2023] [Accepted: 07/27/2023] [Indexed: 10/21/2023] Open
Abstract
Background Ascariasis is a common disease in humans and pigs. In previous reports, it has been known that ascariasis in humans is not only caused by Ascaris lumbricoides but also by Ascaris suum which is known to originate from pigs. Aims and Objectives This research aims to identify the species of Ascaris that infect traditional pig farmers in Bali, Indonesia. Materials and Methods To achieve this, an observational study was conducted, in which 239 feces samples were collected from traditional pig farmers. The collected samples were then divided into two parts, with one part stored in a pot containing 10% formalin for microscopic testing, and the other part stored in 70% ethanol for molecular testing. In cases where Ascaris infection was observed during the microscopic examination, a further test was conducted using the polymerase chain reaction (PCR) method for molecular examination. The DNA derived from the PCR was then subjected to DNA sequencing. Results The result was compared to A. suum gene data previously published in the Gene Bank. The results of the microscopic examination showed that 22 farmers were infected with Ascaris. However, PCR testing and DNA sequencing indicated that three infections were caused by A. suum. Conclusion Therefore, it can be concluded that A. suum is a zoonosis in Bali. Thus, efforts to control ascariasis must pay attention to the presence of pigs around it. Handling of ascariasis is not only carried out in humans but also in pigs and the environment.
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Affiliation(s)
- Kadek Karang Agustina
- Department of Veterinary Public Health, Faculty of Veterinary Medicine, Udayana University, Denpasar, Bali, Indonesia
- Department of Doctoral Program in Biomedical Sciences, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
| | - I Made Ady Wirawan
- Department of Public Health and Preventive Medicine, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
| | - I Made Sudarmaja
- Department of Parasitology, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
| | - I Made Subrata
- Department of Public Health and Preventive Medicine, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia
| | - Nyoman Sadra Dharmawan
- Department of Veterinary Clinical Pathology, Faculty of Veterinary Medicine, Udayana University, Denpasar, Bali, Indonesia
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Development of allele-specific PCR methodology (AS-PCR) to screening A. lumbricoides and A. suum. Parasitol Res 2022; 121:2389-2397. [PMID: 35710846 DOI: 10.1007/s00436-022-07572-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/03/2022] [Indexed: 10/18/2022]
Abstract
Ascaris lumbricoides and Ascaris suum are described as helminths that infect humans and pigs, respectively. It is estimated that infection by A. lumbricoides affects about 447 million individuals living in tropical regions of developing countries. However, there is an increasing number of cases of human ascariasis in countries with no recent history of autochthonous infection by A. lumbricoides. In these places, pigs have been incriminated as the main source of human infection. Conventional parasitological diagnosis does not allow species-specific identification, and the real epidemiological scenario of human and swine ascariasis is still uncertain. Therefore, this work presents the application of a species-specific molecular diagnosis, based on the allele-specific PCR methodology (AS-PCR), using the Internal Transcript Space 1 (ITS-1) of the ribosomal DNA, as a target for differentiating between the two species, using DNA obtained from eggs. To validate the methodology, stool samples positive for Ascaris spp, were obtained from 68 humans from seven Brazilian states and from six pigs from the state of Minas Gerais. All samples obtained from humans were genotyped as A. lumbricoides and all samples obtained from swine were genotyped as A. suum. These results are in agreement with the literature, which demonstrates that in most endemic regions, transmission cycles are separate. Therefore, the execution of this work allowed the availability of a useful methodology for the differential diagnosis of the species, which may contribute to the characterization of the real epidemiological profile of human and swine ascariasis, and to the implementation of future control strategies.
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Nkouayep VR, McManus DP, Mbida M, Gordon CA, Nejsum P. Molecular epidemiology of Ascaris species recovered from humans and pigs in Cameroon. Trans R Soc Trop Med Hyg 2022; 116:949-958. [PMID: 35385862 DOI: 10.1093/trstmh/trac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/22/2022] [Accepted: 03/10/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In Cameroon, considerable research has been conducted on human ascariasis, but no studies have been undertaken to determine whether pigs contribute to the persistence of the infection in children or to unravel the evolutionary relationship between human-derived and pig-derived Ascaris. METHODS DNA was extracted from adult Ascaris worms collected from humans and pigs. Segments of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were sequenced and analysed for 83 worms to dissect the local transmission dynamics of Ascaris in Cameroon. RESULTS The data showed high genetic diversity and revealed demographically expanding populations in the human and pig Ascaris samples. A restricted gene flow between Ascaris lumbricoides and Ascaris suum populations correlating with the preference for humans and pigs, respectively, as hosts was evident. Phylogenetic analyses and haplotype networks split the haplotypes into two major clusters, A and B. However, support for cross-transmission between hosts and hybridization were revealed through shared haplotypes among worms from both hosts. CONCLUSIONS This study provides useful baseline information for future studies of the genetics of Ascaris in Cameroon and suggests that effective and sustainable control of human ascariasis should target both human and pig hosts.
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Affiliation(s)
- Vanessa R Nkouayep
- Research Unit of Biology and Applied Ecology, Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Donald P McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Mpoame Mbida
- Research Unit of Biology and Applied Ecology, Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 067, Dschang, Cameroon
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Peter Nejsum
- Department of Clinical Medicine, Faculty of Health, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark
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Genotyping of Ascaris spp. infecting humans and pigs in Italy, Slovakia and Colombia. INFECTION GENETICS AND EVOLUTION 2021; 94:104997. [PMID: 34252615 DOI: 10.1016/j.meegid.2021.104997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND The systematics and taxonomy of Ascaris lumbricoides and Ascaris suum, two of the world's most widespread nematodes, still represent a highly debated scientific issue. Two different transmission scenarios have been described according to endemicity: separated host-specific transmission cycles in endemic regions, and a single pool of infection shared by humans and pigs in non-endemic regions. The swine roundworm A. suum is now recognized as an important cause of human ascariasis also in endemic areas such as China, where cross-infections and hybridization have also been reported, as well as in non-endemic regions like Italy. This study aimed to investigate the molecular epidemiology of human and pig ascariasis in three countries representing different epidemiological scenarios: Italy as a non-endemic country, Colombia as an endemic country, and Slovakia as a non-endemic country, but with a poor socio-economic context linked to some focal populations of Roma settlements. MATERIALS AND METHODS A total of 237 nematodes were analysed: 46 from Colombia (13 from humans, 33 from pigs), 114 from Slovakia (20 from humans, 94 from pigs) and 77 from Italy (17 from humans and 60 from pigs). Genotyping by PCR-RFLP of nuclear (ITS) and sequencing of mitochondrial (cox1) target regions were performed. ITS genotypes were used to estimate the Hardy-Weinberg (HW) equilibrium according to hosts and country of origin. The partial cox1 sequences were used to analyse genetic polymorphisms according to hosts and country of origin, as well as to infer the network of haplotypes, their evolutionary relationships and geographical distribution. RESULTS 110 quality cox1 sequences were obtained. Haplotype network revealed three main groups corresponding to clade A, B and C. Clade C included most of the human cases from Italy, while those from Slovakia and Colombia were grouped in clade B. Ascaris from Italian and Colombian pigs showed HW equilibrium at the ITS marker, while disequilibrium was found in A. lumbricoides from Slovak pigs, which suggest a high unexpected amount of roundworms of human origin circulating also in pigs. CONCLUSIONS This study updates and extends the current understanding of Ascaris species and genotypes circulating in different epidemiological scenarios, with particular attention to the inclusion of human-derived Ascaris in the phylogenetic cluster C. Despite the evidence of HW equilibrium in the ITS in pig-derived Italian samples, the amount of genetic variation seems to support the existence of two closely related species.
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Zhou C, Guo T, Deng Y, He J, Ouyang S, Wu X. Mitochondrial phylogenomics of human-type Ascaris, pig-type Ascaris, and hybrid Ascaris populations. Vet Parasitol 2020; 287:109256. [PMID: 33053491 DOI: 10.1016/j.vetpar.2020.109256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/25/2020] [Accepted: 09/27/2020] [Indexed: 12/15/2022]
Abstract
Ascaris lumbricoides and Ascaris suum are parasitic nematodes in human and pig intestines. The two species can cross infect and produce hybrids, which contribute to the controversy concerning the taxonomy of A. lumbricoides and A. suum. The purpose of this study was to investigate the microevolutionary process and evolutionary history of human-type Ascaris, pig-type Ascaris, and hybrid Ascaris and provide a theoretical basis for the prevention and control of human and animal ascariasis. The mitochondrial phylogenomics of human-type Ascaris (n = 5), pig-type Ascaris (n = 6), and hybrid Ascaris (n = 6) populations were analyzed using high-throughput sequencing technology. The mitochondrial genomes of human-type Ascaris, pig-type Ascaris, and hybrid Ascaris contained 36 genes (atp8 was missing), including 12 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. All genes were located on the heavy chain. The initiation codons used for protein-coding genes were ATT and TTG and the termination codons were TAA and TAG. The base distribution showed obvious AT preference. The phylogenetic tree based on the Ascaris mitochondrial genomes showed three main clusters (A, B, and C). The Ascaris populations sequenced in this study were all gathered in cluster B. The human-type and hybrid Ascaris populations belonged to different sub-clusters, but the pig-type Ascaris population was more scattered. The mitochondrial genome sequences of the 17 Ascaris individuals in this study did not differ much. The results of this study indicate that Ascaris populations were geographically isolated before host shift. In addition, the data show that there are differences between hybrid Ascaris, human-type Ascaris, and pig-type Ascaris. The information has important theoretical significance and application value.
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Affiliation(s)
- Chunhua Zhou
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China.
| | - Ting Guo
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China
| | - Yuanyu Deng
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China
| | - Jingjing He
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China
| | - Shan Ouyang
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China
| | - Xiaoping Wu
- School of Life Sciences, Nanchang University, Nanchang 330031, People's Republic of China.
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