Detection of Schistosoma mansoni and Schistosoma haematobium by Real-Time PCR with High Resolution Melting Analysis

The present study describes a real-time PCR approach with high resolution melting-curve (HRM) assay developed for the detection and differentiation of Schistosoma mansoni and S. haematobium in fecal and urine samples collected from rural Yemen. The samples were screened by microscopy and PCR for the Schistosoma species infection. A pair of degenerate primers were designed targeting partial regions in the cytochrome oxidase subunit I (cox1) gene of S. mansoni and S. haematobium using real-time PCR-HRM assay. The overall prevalence of schistosomiasis was 31.8%; 23.8% of the participants were infected with S. haematobium and 9.3% were infected with S. mansoni. With regards to the intensity of infections, 22.1% and 77.9% of S. haematobium infections were of heavy and light intensities, respectively. Likewise, 8.1%, 40.5% and 51.4% of S. mansoni infections were of heavy, moderate and light intensities, respectively. The melting points were distinctive for S. mansoni and S. haematobium, categorized by peaks of 76.49 ± 0.25 °C and 75.43 ± 0.26 °C, respectively. HRM analysis showed high detection capability through the amplification of Schistosoma DNA with as low as 0.0001 ng/µL. Significant negative correlations were reported between the real-time PCR-HRM cycle threshold (Ct) values and microscopic egg counts for both S. mansoni in stool and S. haematobium in urine (p < 0.01). In conclusion, this closed-tube HRM protocol provides a potentially powerful screening molecular tool for the detection of S. mansoni and S. haematobium. It is a simple, rapid, accurate, and cost-effective method. Hence, this method is a good alternative approach to probe-based PCR assays.     

Sac-like pouches in Blastocystis from the house lizard Cosymbotus platyurus

We report a 65-year-old male with progressive supranuclear palsy (PSP) who developed bilateral vocal cord abductor paralysis (VCAP). The patient was admitted to our hospital because of impaired gait. He was well until two years earlier, when he began to walk unsteadily. During the next two years, dysarthria and dysphagia developed and his gait worsened gradually. On admission, neurological examination showed impaired vertical and incomplete lateral gaze. His speech was slow and monotonous. Contractures were found in the neck muscles and elbows. The deep tendon reflexes were increased in the upper and decreased in the lower extremities. Babinski sign was negative. Snout and forced grasping reflexes were elicited. He showed marked bradykinesia. Magnetic resonance imaging revealed a midbrain tectum atrophy. Single photon emission tomography showed severe hypoper-fusion in the frontal cortex. No improvement was provided by the administration of levodopa-carbidopa, bromocriptine, droxydopa and amitriptyline. One month after admission, inspiratory stridor developed at night. The laryngofiberscopic examination demonstrated VCAP. An emergency tracheostomy relieved his respiratory distress. Although VCAP rarely occurs in neurodegenerative disorders other than multiple system atrophy, attention to VCAP should be required in PSP patients.