Direct amplification of Entamoeba histolytica DNA from amoebic liver abscess pus using polymerase chain reaction

An important and serious complication of intestinal infection with Entamoeb a histolytica is the involvement of the liver (hepatic amoebiasis). Hepatic amoebiasis is usually diagnosed by the clinical picture (pain in the right upper quadrant and fever), ultrasound examination and positive serology. H owever, none of these tests are definitive and the picture overlaps with py ogenic liver abscess caused by bacteria. It is for this reason that the fea sibility of using polymerase chain reaction (PCR) for the detection of E. h istolytica DNA in liver abscess pus was investigated. A comparative study w as done to verify the sensitivity of ten pairs of primers specific for dete cting E. histolytica in stools. Samples of liver abscess pus from 22 serolo gy-positive patients were collected under ultrasound guidance; and these we re used directly in PCR assays without any prior pre-treatment of the sampl es. Of the ten pairs of previously published primers tested, two pairs of p rimers (P1 + P2 and P11 + P12) were found to give 100% sensitivity. Based o n these results, we recommend that PCR assay can be successfully used to co nfirm the diagnosis of amoebic liver abscess with the primers identified.