ABSTRACT
BACKGROUND AND OBJECTIVE: Identification of Entamoeba histolytica (E. histolytica) by microscopy alone can be problematic because E. dispar and E. moshkovskii are morphologically similar to E. histolytica. Therefore, this study aimed to assess the performance of microscopy in the detection of E. histolytica in stool specimens with the help of PCR-based assays and enzyme-linked immunosorbent assay (ELISA). MATERIALS AND METHODS: Between September, 2017 and September, 2018, 200 stool specimens were obtained from Jordanian patients with suspected amebiasis. All specimens were subjected to microscopic analysis. DNA was extracted from the microscopy-positive stool samples. A conventional PCR and a duplex real-time PCR were performed to detect E. histolytica and E. dispar. RESULTS: By microscopy, 35% (70/200) of specimens were tested positive for Entamoeba complex. All 70 microscopic-positive Entamoeba complex samples were negative for the presence of E. histolytica by the NOVITEC® E. histolytica ELISA assay. All 70 samples positive by microscopy were negative for the presence of E. histolytica and E. dispar by PCR-based assays. CONCLUSION: We suspect some of these microscopy-positive stool specimens might contain a potentially novel species of Entamoeba that could not be detected by ELISA or PCR-based assays specific for E. histolytica and E. dispar. Diagnosis of amebiasis remains challenging here in Jordan and hence highlighting the need for improved diagnostic method.
Subject(s)
Entamoeba histolytica , Entamoebiasis/diagnosis , Entamoebiasis/parasitology , Polymerase Chain Reaction/methods , Adolescent , Adult , Aged , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Feces , Female , Humans , Jordan , Male , Middle Aged , Real-Time Polymerase Chain Reaction , Young AdultABSTRACT
BACKGROUND: C1q protein is composed of three protein chains (A, B and C) that are the products of separate genes. Genetic deficiencies in C1Q genes are important factors influencing the risk of systemic lupus erythematosus (SLE). Therefore, this study aimed to investigate the possible association of single nucleotide polymorphisms (SNPs) in the coding region of the C1Q genes with SLE. METHODS: To search for potential SNPs in the encoding regions of C1q A, B and C chains, Cq1 exons were initially amplified and directly sequenced from leukocyte DNA from a subset of Caucasian and African American SLE patients and healthy controls. The sequences were analyzed by the Phrap and Phred software analysis system and the SNPs were identified by visual inspection. To test if any of these SNPs were linked to susceptibility to SLE, they were measured in 210 SLE patients ((59 African Americans and 151 Caucasians) and 129 matched healthy controls (55 African Americans and 74 Caucasians) by restriction fragment length polymorphism analysis. RESULTS: The sequencing phase of the study identified three synonymous SNPs: Nucleotide 276G>A in C1QA, 66C>A in C1QB and 129G>A in C1QC. Statistically, no differences were found in genotype or allele frequencies between patients and controls for the 276G>A or 66C>A SNP. However, in Caucasians, the frequencies of the 129G>A genotypes were significantly different between SLE patients and controls (P = 0.005), specifically with the GG genotype being over represented in the controls (P = 0.004). CONCLUSION: The results show that the homozygous 129GG genotype is associated with protection against SLE onset. This protection is race dependent, being observed in Caucasians but not African Americans. The mechanism of this association is currently unclear.
