molecular characterization of eimeria species naturally infecting egyptian baldi chickens.

background: coccidiosis is a serious protozoal disease of poultry. the iden-tification of eimeria species has important implications for diagnosis and con-trol as well as for epidemiology. the molecular characterization of eimeria spe-cies infecting egyptian baladi chickens was investigated. methods: eimeria species oocysts were harvested from intestines of naturally infected egyptian baldi chickens. the morphometry characterization of oocysts along with coccimorph software was done. the dna was extracted ini-tially by freezing and thawing then the prepared samples was subjected to commercial dna kits. the dna products were analyzed through conven-tional polymerase chain reaction by using amplified region (scar) marker. results: the pcr results confirmed the presence of 7 eimeria species in the examined fecal samples of egyptian baldi breed with their specific ampilicon sizes being e. acervulina (811bp), e. brunette (626bp), e. tenella (539bp), e. max-ima (272bp), e. necatrix (200bp), e. mitis (327bp) and e. praecopx (354bp). a sequencing of the two most predominant species of eimeria was done, on e. tenella and e. máxima . analysis of the obtained sequences revealed high identi-ties 99% between egyptian isolates and the reference one. similarly, e. maxima isolated from egyptian baldi chickens showed 98% nucleotide identities with the reference strain. only single nucleotide substitution was observed among the egyptian e. tenella isolates (a181g) when compared to the reference one. the egyptian isolates acquired 4 unique mutations (a68t, c164t, g190a and c227g) in compared with the reference sequence. conclusion: this is the first time to identify the 7 species of eimeria from egyptian baladi chickens.