ABSTRACT
Purpose: The aim of the present study was to evaluate the use of touchdown polymerase chain reaction (TD-PCR) for the detection of Entamoeba histolytica in liver pus samples obtained from patients with a clinical diagnosis of amoebic liver abscess (ALA) using small-subunit rRNA (SSU rRNA) as the target gene. Materials and Methods: Microscopic examination in vitro culture and serological test for the detection of E. histolytica in 67 pus samples obtained from ALA patients was performed. Molecular studies were carried out by both conventional PCR and TD-PCR targeting the SSU rRNA gene using the same sets of primers and the results were compared. Results: TD-PCR detected the presence of E. histolytica in 86.5% of the liver pus samples within 2.5 h as compared with 82.08% by conventional PCR within 3.5-4 h. Conclusion: TD-PCR assay may serve as a relatively better detection method for E. histolytica over conventional PCR with respect to the turnaround time, increased sensitivity, specificity and yield.
Subject(s)
Clinical Laboratory Techniques/methods , DNA Primers/genetics , Entamoeba histolytica/genetics , Entamoeba histolytica/isolation & purification , Humans , Liver Abscess, Amebic/diagnosis , Liver Abscess, Amebic/parasitology , Parasitology/methods , Polymerase Chain Reaction/methods , RNA, Protozoan/genetics , RNA, Ribosomal, 18S/genetics , Sensitivity and Specificity , Suppuration/parasitology , Time FactorsABSTRACT
Two species of Cryptosporidium are known to infect man; C. hominis which shows anthroponotic transmission between humans, and C. parvum which shows zoonotic transmission between animals or between animals and man. In this study, we focused on identifying genotypes of Cryptosporidium prevalent among inhabitants and domestic animals (cattle and goats), to elucidate transmittal routes in a known endemic area in Hwasun-gun, Jeollanam-do, Republic of Korea. The existence of Cryptosporidium oocysts was confirmed using a modified Ziehl- Neelsen stain. Human infections were found in 7 (25.9%) of 27 people examined. Cattle cryptosporidiosis cases constituted 7 (41.2%) of 17 examined, and goat cases 3 (42.9%) of 7 examined. Species characterizations were performed on the small subunit of the rRNA gene using both PCR-RFLP and sequence analysis. Most of the human isolates were mixtures of C. hominis and C. parvum genotypes and similar PCR-RFLP patterns were observed in cattle and goat isolates. However, sequence analyses identified only C. hominis in all isolates examined. The natural infection of cattle and goats with C. hominis is a new and unique finding in the present study. It is suggested that human cryptosporidiosis in the studied area is caused by mixtures of C. hominis and C. parvum oocysts originating from both inhabitants and domestic animals.