Sequence and Morphology of Cysticercus pisiformis in Local Breed Rabbits

Abstract

The current study was aimed to identified Cysticercus pisiformis of local breed rabbits (2 to 24 months old) based on morphologically and molecular detection by using NAD1 and COX1 genes and conventional PCR during the period from 1/ March / until 31/ May/ 2022 in Baghdad city, Iraq. Rabbits were humanely euthanized and abdomen opened longitudinally to looking for any cyst may be founded grossly in the peritoneal cavity or on the visceral organs, all cysts were examined for their structures scolex, membrane and the size measurements. The fluid was collected from each cyst for measurement the volume, and some cysts were stained with a cetoacetic acid carmine stain to seen the structure of cysts. To confirm the diagnosis of C. pisiformis (scolex and part of membrane) from these cysts were put in a 70% ethanol for further used in conventional molecular diagnosis. The results revealed that an overall infection rate was 23.33% (14/60). The females infection rate was 27.90% (12/43) and in the males 11.76% (2/17) without significant differences (P≥0.05 ). Fifty-five cysts were isolated from abdominal cavity of 14 positive samples as balloon filled with clear fluid, white floating scolex (evagenated or invagenated) or pus-filled in the older cysts , distribution of cysts was 47.27% (26/55) in mesentery, 21.82% (12/55) in liver, 21.82% (12/55) free within abdominal cavity and 9.09% (5/55) in omentum with Significant differences (P<0.05). The cyst diameters range between 7-21mm. in length and 4-10mm. in width. The PCR amplification results of 14 positive samples for NAD1 (500bp.) and COX1 (446bp.) genes and 3 isolates were squincing and submitted to GenBank under the accession numbers (LC731847.1, LC731848.1 and LC731849.1) for NAD1 gene are 100% identical to the China isolate ( JN870149.1), while less identically (97.15 -99.47%) to Australia and Poland isolates, and OP274120.1, OP277616.1 and OP277618.1 for the COX1 gene the matching between 99.56% -100% for China, Portugal and Poland. Finally, this is the first genetic investigation for the identification of local C. pisiformis, which has revealed a high infection rate of the parasite in local breed rabbits in Baghdad, Iraq.