Determining the prevalence of Oesophagostomum bifurcum and Necator americanus infections using specific PCR amplification of DNA from faecal samples

Abstract

SummaryUntil recently infection of humans with Oesophagostomum bifurcum was regarded as a rare zoonosis. But in northern Togo and Ghana its prevalence is 50% or more in certain villages. Diagnosis is hampered by the fact that the eggs of O. bifurcum are morphologically identical to those of the hookworm Necator americanus. Stools have to be cultured for 7 days to allow eggs to hatch to the characteristic third-stage (L3) larvae. We evaluated the applicability of speci®c polymerase chain reactions (PCRs) to amplify DNA from faecal samples as an alternative method for the differential diagnosis of the two infections. Oesophagostomum bifurcum-PCR was positive in 57 of 61 faecal samples known to contain O. bifurcum L3 larvae in coproculture. Necator americanus PCR was positive in 137 of 146 faecal samples known to contain N. americanus L3 larvae in coproculture. PCR also detected 26 additional O. bifurcum cases in 72 samples from O. bifurcum endemic villages in which no O. bifurcum larvae were found and 45 N. americanus cases in 78 samples in which no N. americanus larvae were found in coproculture. No O. bifurcum DNA was detected in 91 stool samples from individuals from two non-endemic villages. These results prove the usefulness of speci®c PCR assays as epidemiological tools to estimate the prevalence of O. bifurcum and N. americanus infections in human populations.keywords Oesophagostomum bifurcum, Necator americanus, parasitic nematodes, diagnosis, speci®c diagnosis by PCR correspondence Jaco J. Verweij,

Application of multiplex PCR for the simultaneous detection of Taenia spp. from domestic dogs in the north of Iran

“…was extracted using the QIAamp DNA Mini kit (Qiagen, Germany) according to the kit's protocol with slight modifications (Verweij et al, 2001). DNA extraction was performed just on stool samples which were positive with zinc chloride fl otation method.…”

“…Among different PCR methods, multiplex PCR is considered useful for the detection of taeniid eggs from both individual animals, as well as in epidemiological studies (Trachsel, et al, 2007). A previous study (Yamasaki et al, 2004) had successfully demonstrated a multiplex PCR assay for the differential diagnosis of taeniasis and cysticercosis in humans (Taenia saginata, T. asiatica, and T. solium). This technique is therefore very useful in the accurate identifi cation of Taeniid cestode eggs, and overcomes the limitations of identifi cation by morphology (Yamasaki et al, 2004).…”

“…A previous study (Yamasaki et al, 2004) had successfully demonstrated a multiplex PCR assay for the differential diagnosis of taeniasis and cysticercosis in humans (Taenia saginata, T. asiatica, and T. solium). This technique is therefore very useful in the accurate identifi cation of Taeniid cestode eggs, and overcomes the limitations of identifi cation by morphology (Yamasaki et al, 2004). Some studies have been carried out on wild and stray dogs; however, little attention has been paid to domestic dogs, which have been underestimated regarding their parasitic burdens and public health signifi cance (Mehrabani et al, 1999;Dalimi et al, 2006).…”

High Throughput Multiplex PCR and Probe-based Detection with Luminex Beads for Seven Intestinal Parasites

“…3 The DNA extraction for the specimens from LUMC was performed using regular QIAamp mini Kit spin columns with modifications, which included a pretreatment with PVPP (polyvinylpyrrolidone) and boiling. 12 Protozoa-positive controls were extracted using an automated nucleic acid isolation system, QuickGene-810, with QuickGene DNA tissue kit S (Fujifilm, Tokyo, Japan). The manufacturer's protocol was modified to accommodate a larger input stool volume of 200 mg.…”

A Pentaplex Real-Time Polymerase Chain Reaction Assay for Detection of Four Species of Soil-Transmitted Helminths

“…[9][10][11][12][13][14][15] Realtime PCR has proved to be highly sensitive and 100% specific in detecting S. stercoralis and hookworm infections as compared with microscopy. 9,15 Hence, real-time PCR of several helminth species provides a worthwhile diagnostic alternative because it allows multiplex detection and quantification while it decreases the chances of human error and DNA contamination as compared with conventional PCR.…”