A Real-Time PCR Assay for Simultaneous Detection and Differentiation of Four Common Entamoeba Species That Infect Humans

Identification of toxic Gelsemium elegans in processed food and honey based on real-time PCR analysis

Gelsemium elegans (GE) is a widely distributed hypertoxic plant that has caused many food poisoning incidents. Its pollen can also be collected by bees to produce toxic honey, posing a great threat to the health and safety of consumers. However, for the complex matrices such as cooked food and honey, it is challenging to perform composition analysis. It is necessary to establish more effective strategies for investigating GE contamination. In this study, the real-time PCR (qPCR) analysis combined with DNA barcode matK was proposed for the identification and detection of GE. Fifteen honey samples along with twenty-eight individuals of GE and the common confusable objects Lonicera japonica, Ficus hirta, Stellera chamaejasme and Chelidonium majus were gathered. Additionally, the food mixtures treated with 20-min boiling and 30-min digestion were prepared. Specific primers were designed, and the detection capability and sensitivity of qPCR in honey and boiled and digested food matrices were tested. The results demonstrated that the matK sequence with sufficient mutation sites was an effective molecular marker for species differentiation. GE and the confusable species could be clearly classified by the fluorescence signal of qPCR assay with a high sensitivity of 0.001 ng/μl. In addition, this method was successfully employed for the detection of deeply processed food materials and honey containing GE plants which even accounted for only 0.1 %. The sequencing-free qPCR approach undoubtedly can serve as a robust support for the quality supervision of honey industry and the prevention and diagnosis of food poisoning.

Parasites in surgically removed appendices as a neglected public health concern: a systematic review and meta-analysis

The role of various parasitic infections in the occurrence of appendicitis is illustrated through cases recorded all over the world. The purpose of the current study was to estimate the global prevalence of parasite infestation (other than E. vermicularis) in appendectomy specimens.In the setting of the PRISMA guidelines, multiple databases (Science Direct, Scopus, Web of Science, PubMed, and Google Scholar) were explored in articles published until 28 September 2020. Totally, 62 studies (106 datasets) with 77, 619 participants were included in the analysis.The pooled prevalence of parasites in appendectomy samples was as follows; 0.012% (95% CI; 0.004-0.025) for Ascaris lumbricoides, 0.004% (95% CI; 0.001-0.009) for Trichuris trichiura, 0.025% (95% CI; 0.007-0.052) for Schistosoma mansoni, 0.002% (95% CI; 0.001-0.005) for Taenia spp., 0.061% (95% CI; 0.020-0.122) for Entamoeba histolytica and 0.034% (95% CI; 0.018-0.056) for Giardia lamblia.Our results demonstrated that the risk of appendicitis may increase in the presence of helminth and protozoan infections. As such, the most cases of parasites in appendectomy specimens were reported in developing countries. Regular screening plans for diagnosis, treatment and prevention are needed for prevention of parasitic infection as well as parasitic associated appendicitis, especially in endemic regions of the world.

Epidemiology of clinically relevant Entamoeba spp. (E. histolytica/dispar/moshkovskii/bangladeshi): A cross sectional study from North India

BACKGROUND

Entamoeba infections have major impact on millions of the people worldwide. Entamoeba histolytica has long been accepted as the only pathogenic species. However, recent reports of other Entamoeba spp. in symptomatic cases have raised questions on their pathogenicity.

METHODOLOGY/PRINCIPAL FINDINGS

Total 474 stool samples and 125 liver aspirates from patients with intestinal and extra intestinal manifestations and from community were included. Sewage samples from the hospital and the city were also included. Microscopic examination and molecular detection were performed to detect presence of E. histolytica/ dispar/ moshkovskii/ bangladeshi. The associated demographic and socioeconomic factors were statistically analyzed with the presence of Entamoeba. Microscopy detected Entamoeba spp. in 5.4% stool and 6.4% liver aspirate samples. Through nested multiplex PCR, prevalence of Entamoeba spp. in intestinal and extra-intestinal cases was 6.6% (20/301) and 86.4% (108/125) respectively and in asymptomatic population was 10.5% (13/123). Sewage samples did not show presence of any Entamoeba spp. Uneducated subjects, low economic conditions, untreated drinking water, consumption of raw vegetables and habit of not washing hands before meals were significantly associated with presence of Entamoeba spp.

CONCLUSIONS

E. histolytica still remains the only Entamoeba spp. in invasive extra intestinal infections. E. dispar was detected in both asymptomatic and symptomatic intestinal infections. Routine identification of Entamoeba spp. should incorporate PCR based detection methods.