Molecular Characterization of Fasciola hepatica in Sheep Based on DNA Sequences of Ribosomal ITS-1

Optimization and workflow of in vitro culture of adult Fasciola hepatica

The aim of this study was to evaluate different transportation and incubation conditions to test the viability of adult Fasciola hepatica in order to propose a new cultivation workflow. The adult stage of F. hepatica was obtained from naturally infected cattle at a local slaughterhouse in Lima, Peru. Different transport and incubation conditions of F. hepatica were tested, evaluating its viability through a motility scale. DMEM and RPMI 1640 media presented better transport conditions compared to Hedon-Fleig and PBS media (p < 0.001), maintaining the flukes at 37°C. Also, DMEM and RPMI-1640 media presented better incubation conditions compared to Hedon-fleig (p < 0.001). A minimum of 3 ml of medium per fluke was required to maintain best viability (p < 0.001) and no differences in viability were found between the different types of culture plates (p > 0.05). In addition, we found that incubation with DMSO (dimethyl sulfoxide) at concentrations greater than 0.5% v/v for 48 hours generates toxicity (p < 0.001). In conclusion, RPMI 1640 and DMEN media presented better transport and in vitro cultivation conditions for F. hepatica, using DMSO at concentrations lower than 0.5% v/v.

Fasciola hepatica Excretory-Secretory Products (Fh-ES) Either Do Not Affect miRNA Expression Profile in THP-1 Macrophages or the Changes Are Undetectable by a Microarray Technique

Fasciola hepatica is a liver fluke that resides in the bile ducts of various mammals. The parasitosis leads to economic losses in animal production estimated at USD 3.2 billion annually. It is also considered a zoonosis of great significance and a problem for public health affecting 2.4 million people worldwide. Nevertheless, besides the negative aspects of infestation, the antigens released by the fluke, F. hepatica Excretory-Secretory Products (Fh-ES) contain several immunomodulatory molecules that may be beneficial during the course of type I diabetes, multiple sclerosis, ulcerative colitis, or septic shock. This phenomenon is based on the natural abilities of adult F. hepatica to suppress proinflammatory responses. To underline the molecular basis of these mechanisms and determine the role of microRNA (miRNA) in the process, lipopolysaccharide (LPS)-activated THP-1 macrophages were stimulated with Fh-ES, followed by miRNA microarray analyses. Surprisingly, no results indicating changes in the miRNA expression profile were noted (p < 0.05). We discuss potential reasons for these results, which may be due to insufficient sensitivity to detect slight changes in miRNA expression or the possibility that these changes are not regulated by miRNA. Despite the negative data, this work may contribute to the future planning of experiments by other researchers.

Molecular Characterization of Liver Fluke Isolated from Sheep, Goat and Cattle in Sulaymaniyah, Iraq

Background

We aimed to determine species of liver fluke that predominately cause fascioliasis in sheep, goats, and cattle in the Sulaymaniyah Province, Iraq using the molecular technique of DNA sequencing and restriction fragment length polymorphism (RFLP).

Methods

The samples were collected from November 2021 to May 2022. The flukes were collected from infected livers of livestock at the slaughterhouse of Sulaymaniyah Governorate, Iraq. A total of 205 flukes were collected from 56 hosts, cattle (n=22), sheep (n=28), and goats (n=6). The specific primers for FCOX1 and 28S rDNA gene amplification were used. The PCR products were subjected to restriction fragment polymorphism (RFLP) assay using Hpy188III and Dra II restriction enzymes, besides DNA sequencing.

Results

The results showed the genetic polymorphisms among the flukes. Three patterns of RFLP were observed Fasciola hepatica, F. gigantica, and F. intermediate, where 28 of them displayed F. hepatica (sheep, n=14, goat, n=3 and cattle, n= 11), whereas 24 samples displayed the F. gigantica (sheep, n=12, goat, n=3 and cattle, n= 9), and only four samples belonged to F. intermediate (sheep n=3 and cattle, n=1). In addition, the result of the ribosomal DNA (28S rDNA) sequencing confirmed that the isolated flukes belonged to F. hepatica, F. gigantica and F. intermediate.

Conclusion

All three main species are present in the study area and F. hepatica predominated among the animal species in this area also, our results concluded that PCR-RFLP is a rapid and reliable method for liver fluke species identification.