Genetic Transfer of Anticoccidial Drug Resistance in Eimeria tenella

Tk, Jeffers

doi:10.2307/3278505

Cited by 38 publications

(18 citation statements)

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“…However, the most popular opinion for the development of drug resistance is the endogenous mutations occurring in coccidian parasite [34]. Because of continuous and prolonged use of anticoccidial drugs, mutations have been observed among coccidian population during this continuous selection process.…”

Section: Discussionmentioning

confidence: 99%

Genetic diversity and drug sensitivity studies on Eimeria tenella field isolates from Hubei Province of China

Tan

Yang

et al. 2017

Parasites Vectors

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BackgroundAvian coccidiosis is an intracellular intestinal parasitic disease, caused by intracellular intestinal parasites from the genus Eimeria, among which Eimeria tenella is one of the most pathogenic species and causes great economic losses. Frequent applications of anticoccidial drugs have resulted in the development of drug-resistance in E. tenella. In the present study, we sought to determine the genetic diversity of E. tenella isolates prevalent in chicken farms in Hubei Province of China and examine their sensitivity to three anticoccidial drugs. The results provide useful information for the prevention and control of coccidiosis in this region.Methods Eimeria tenella oocysts were isolated from faecal samples collected from different commercial broiler production farms in Hubei Province, China. After oocyst sporulation and animal inoculation for expansion of the field isolates, DNA and RNA were extracted from excysted sporozoites for molecular characterization. Species identification of field isolates were performed by polymerase chain reaction (PCR) amplification of the internal transcribed spacer 1 (ITS1) region of ribosomal DNA. Random amplified polymorphic DNA (RAPD) was used for population genetic analysis. Subsequently, sequences of the major sporozoite surface antigen (SAG), micronemal protein 2 (MIC-2) and cytochrome b (cytb) genes from genomic DNA, and the Eimeria tenella cation-transport ATPase (EtCat ATPase) gene from cDNA were obtained for genotyping using multi-sequence alignments. Finally, sensitivity of the field isolates to three commonly used anticoccidial drugs (diclazuril, decoquinate and maduramycin) were tested to assess the prevalence of drug resistance in E. tenella in Hubei Province of China.ResultsAnalysis of the ITS1 sequences indicated that all the isolates were E. tenella. RAPD analysis and multi-sequence alignments of the SAG, MIC-2, EtCat ATPase and cytb showed genetic diversity among these isolates. Finally, drug sensitivity tests demonstrated that all field isolates were sensitive to diclazuril but resistant to decoquinate (except for the isolates from eastern Hubei) and maduramicin.ConclusionsPopulation genetic analysis indicated that genetic polymorphisms among field isolates were closely related with their regional distributions. Drug sensitivity testing demonstrated that E. tenella isolates in Hubei Province were sensitive to diclazuril, but resistant to maduramycin and decoquinate. The results presented here provide important information for the control and preventions of coccidiosis in the Hubei Province of China.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2067-y) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

Genetic diversity and drug sensitivity studies on Eimeria tenella field isolates from Hubei Province of China

Tan

Yang

et al. 2017

Parasites Vectors

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“…However, the impact of coccidiosis vaccines in restoring drug sensitivity to be described is largely due to replacement of the resident population of coccidia by vaccine-derived drug-sensitive coccidia, because the rate of genetic recombination in avian coccidia is likely quite low. For example, recombinant coccidia constituted no more than 0.04% of the total oocysts produced in a cross between drug-sensitive and drug-resistant strains of Eimeria tenella ( Jeffers, 1974d ). Although a greater degree of hybridization was found in a cross of two drug-resistant strains of E. tenella , the recombinant coccidia still only comprised 1.5% of the total oocysts produced.…”

Section: Life Cycle and Genetics Of Eimeriamentioning

confidence: 99%

Vaccination of chickens against coccidiosis ameliorates drug resistance in commercial poultry production

Chapman

Jeffers

2014

International Journal for Parasitology: Drugs and Drug Resistan

120

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“…This provides a theoretical basis for our understanding of the rate at which resistance may be acquired in the field. Jeffers was the first to demonstrate that it is possible to experimentally develop recombinant phenotypes utilizing strains resistant to different anticoccidial drugs (Jeffers, 1974a). Crosses were made between strains of E. tenella differing in resistance to amprolium and decoquinate and phenotypes resistant to both drugs obtained.…”

Section: Biographymentioning

confidence: 99%

Thomas K. Jeffers: pioneer of coccidiosis research

Chapman

2012

Avian Pathology

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Thomas K. Jeffers has made many significant contributions to our understanding of the biology of the parasite Eimeria, the cause of coccidiosis in poultry. His work has had direct practical application for the control of this widespread disease. Topics discussed include Jeffers' pioneering work concerned with genetics of the host response to infection, the nature of biological and immunological intraspecific variation, drug resistance and discovery, field surveys of resistance, and his most recognized achievement-the demonstration that the lifecycle of coccidia may be altered by artificial selection. Parasites so modified are attenuated but retain their immunogenicity, a discovery that has led to the development of live vaccines that are inherently non-pathogenic. This article provides a brief biography and describes the contributions that Jeffers has made to our knowledge of coccidiosis.

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Genetic Transfer of Anticoccidial Drug Resistance in Eimeria tenella

Cited by 38 publications

References 0 publications

Genetic diversity and drug sensitivity studies on Eimeria tenella field isolates from Hubei Province of China

Genetic diversity and drug sensitivity studies on Eimeria tenella field isolates from Hubei Province of China

Vaccination of chickens against coccidiosis ameliorates drug resistance in commercial poultry production

Thomas K. Jeffers: pioneer of coccidiosis research

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