Abstract
BACKGROUND: Even though E. histolytica is recognized as an effective pathogen, what determines the outcome of this infection is still not well understood. The present study was carried out to determine the genetic characteristics of E. histolytica isolates from two different regions in South Africa. METHOD: Diarrheal and non-diarrheal stool samples were collected from patients of all ages from Giyani and Pretoria. Different PCR protocols were used to identify E. histolytica and amplify the serine rich E. histolytica protein (SREHP) and chitinase genes. The profiles obtained were compared among the different samples.RESULTS: Out of 111 stool samples collected, 51 were positive by either PCR or microscopy and 14 samples were positive by both methods. The serine- rich E. histolytica protein was amplified in 26 samples. Out of the 26 samples (19) different SREHP profiles were obtained. SREHP #2 was obtained in 5 different samples, 4 from Pretoria and 1 from Giyani (2 diarrheal and 3 non-diarrheal). The chitinase gene was amplified from 51 samples and 22 different chitinase profiles were obtained. Of all the profiles, profile #4 was found in 6 different isolates, 5 from Giyani and 1 from Pretoria (3 symptomatic and 3 asymptomatic). However, profile # 18 was only found in formed stools from Giyani. CONCLUSIONS. The results obtained in this study have further confirmed the genetic heterogeneity of E. histolytica for the SREHP and chitinase genes which might have a significant influence in the outcome of amebic infection, depending on the genetic profile of the infecting strain.
Molecular characterization of novel H-2 class I molecules expressed by a C3H UV-induced fibrosarcoma.