Isolation and Establishment of eimeria tenella Populations from Local Broiler Chicken Farms

Abstract

Coccidiosis is a major intestinal disease in the chicken production industry that is caused by one or more of the seven Eimeria species known to infect chickens. Development of effective diagnostic methods and controls requires comprehensive knowledge on the Eimeria species in the local population, particularly the pathogenic E. tenella. In this study, 35 faecal samples were collected from local chicken farms, and through microscopic observation, nine samples (26%) were found to contain Eimeria oocysts. Subsequently, two positive samples, namely NSN6 and SGR6, were selected and propagated via passage in coccidian-free chickens. Species identification analyses based on oocyst morphological characterisation suggested the presence of small-sized oocysts (E. acervulina and/or E. mitis) and medium-sized oocysts (E. necatrix, E. tenella, and/or E. praecox) in NSN6 while in SGR6, the large-sized oocysts (E. brunetti and/or E. maxima) were also present in addition to the small and medium-sized oocysts. Subsequently, species identification with PCR using species-specific primers was successful in determining the presence of specific Eimeria species, which are E. acervulina and E. tenella in NSN6, and E. acervulina, E. tenella, and E. maxima in SGR6. The E. tenella populations of NSN6 and SGR6, namely EtNSN6 and EtSGR6, respectively, were established via passage in coccidian-free chickens and oocyst recovery from the caeca. The purity of EtNSN6 and EtSGR6 populations were confirmed based on oocyst morphological characterisation and PCR. The established EtNSN6 and EtSGR6 populations would be useful as research models for local strains in the development of more effective control methods.

Characterization of internal transcribed spacer-1 and apical membrane antigen-1 sequences provides insights into the genetic diversity of Eimeria tenella strains

“…The genomic DNA isolated from two local E. tenella strains, namely EtNSN6 and EtSGR6 that were previously established by Loo et al (2022), were prepared with the concentration of >30 ng/µL and the total mass of >1 µg. The DNA purity was ensured to be in the range of 1.8-2.0 for A 260/280 and 2.0-2.2 for A 260/230 .…”

“…E. tenella ITS-1 and AMA-1 sequence generation E. tenella populations from locally collected samples, namely EtNSN6 and EtSGR6 were established as previously reported (Loo et al, 2022). Genomic DNA was extracted from purified oocysts based on the protocol previously described by Fernandez et al (2003aFernandez et al ( , 2003b with minor modifications (Loo et al, 2019).…”

“…Globally, the prevalence of coccidiosis is estimated to occur at 5% for clinical infections while subclinical infections are as high as 20% (Shirley et al, 2005). In Malaysia, a study of 35 fecal samples from local chicken farms located in four states of Peninsular Malaysia (Selangor, Negeri Sembilan, Pahang and Johor), reported the prevalence of coccidiosis infection to be 26% (Loo et al, 2022). Additionally, a study of 135 village chicken fecal samples from Kelantan reported a prevalence of coccidiosis infection of 7.4% (Norulhuda et al, 2017), while a study of 240 fecal samples from Penang and Perak reported a higher prevalence of coccidiosis infection of 27.1% (Haziqah & Irwan-Izzauddin, 2019).…”