Prevalence and incidence of tape worms in Al Taif governorate.
The present study was designed to assess an epidemiological study of cestodes among sheep at Al-Taif governate throughout the whole year from October 2015 to September 2016 in KSA. In the current study the incidence of natural infection with tapeworms was (9.94%), which is in agreement with many other scientific reports [24, 25, 26, 27], while higher values were reported in this study than those reported by other authors [28, 29] and lower than that recorded by Kumar [30] to 28.5%. These differences may be due to host habits in different countries, parasites, vectors and many environmental factors.
It was found that the highest percent of positively was recorded in October (20%), while the lowest percent was in September (5%). According to seasons, it was found that the incidence of tapeworms among sheep was high in winter (11.3), while it is least in spring season (7.72) as shown in Table (1). The results of seasonal incidence of tape worms among sheep recorded in this study were nearly the same all over the year, except for spring. This could be attributed to the climatic conditions including temperature, relative humidity and rainy weather which were favorable to the survival and development of larval stages which were strongly supported by Qamar [31], and the intermediate hosts (oribatid mites) on pasture in Al Taif governorate [32].
The worms that were identified in this study listed in Table (2), Avitellina centripunctata (39.5%), Moniezia expansa and Moniezia benedeni (36.4%), Thysaniezia giardia (15.6%), and Stilesia hepatica (8.3%). With regard to parasite prevalence throughout the year, the highest values of infection with Moniezia spp. were recorded during the autumn season, and this was consistent with [33, 34].
Molecular characterization of Moniezia spp.
The present results agreed with Diopa [35], they revealed that according to a phylogenetic analysis based on cox1 gene sequences in tapeworms from goats/sheeps and that from cattle were genetically different from each other. The percentage of Al Taif Moniezia species cox1 gene identity were ranged from 90–99%; in which Taif strains Me Taif1, Me Taif3 and Me Taif4 have identity percentage 99% in alignment to subjects Me13 (accession number: AB821384.1), Me13 and Me14 (accession number: AB821385.1), respectively but Me Taif2 shows 90% identity percentage for subject sequence Me22 (accession number: AB821393.1).
Diopa [35] reported that most Moniezia species cox1 gene (375 bp) of Senegal and Ethiopia including Me13, Me14 and Me22 were already found in Japan tapeworms in the GenBank database with accession number: AB099693 in Genbank [36], but there is no host information in the database. They stated that no relevant papers were published and the data was only published in the database. In addition, they compared with the sequences obtained from Moniezia sp. (AB099693) and was equally genetically distant to all the sequences with the similarity of 86.7–87.7%.
The present study revealed the genetic diversity of Al Taif Moniezia sp. might be due to intraspecific variation. This suggestion agreed with Diopa [35], they suggest that the mitochondrial variability of M. expansa in Senegal is due to intraspecific variation rather than interspecific among cryptic species. For anoplocephalid cestodes no reports were found of intraspecific variation of the cox1 gene sequences between them, but some other types of cyclophyllidean cestodes such as Echinococcus multilocularis and Taenia solium had genetic sub-group in the world with the listed as 1.9% and 1.3%, respectively [37, 38].
In vitro anthelminthic efficacy of Spirulina platensis extract on Monizia spp.
As per to our knowledge, it is the first time to assess the anthelminthic potential of Spirulina platensis extract on Monizia spp. that was reported by deformation of the tape worm morphology that was treated with Spirulina platensis extract at different concentrations by scanning electron microscopic examination.
The outer surface or tegument is the area of contact between the environment in the host and Monizia, so the tegument has many functions and features, which have made the study of great importance, because the outer surface of the tape worm is the main target site for different natural anthelmintic products and synthetic drugs as proved by ultrastructural and histomorphological studies [39, 40]. These changes depend on the concentration of the extract and the incubation period, leading to deformation and destruction in the scolex and proglottis as well as in the cuticle tegumental architecture of M. expansa. One of the main characteristics of parasite cuticle is metabolically active as well as specialized in the selection and absorption of nutrients and the osmoregulation process. Therefore, the deformities and destructive changes on the parasite surface are responsible for the passive diffusion of anthelminthic through the cuticle [41, 42].
Mossa [43] reported that using different plant extracts of Kingdom of Saudi Arabia have high efficacy in the treatment of Ascariasis and fascioliasis. It had also a bactericidal effect and molluscicidal activity of Schistosoma mansoni and also with less side effects and less expensive than other chemical drugs.
The effect of ethanolic extract of Calligonum comosum and TCBZ on adult worms of Fasciola gigantica was studied by Degheidy [44] through biochemical and hematological examination. Their results showed a decrease in the number of eggs in the feces and also the blood parameter returned to its normal levels after treatment, which led to the improvement of the health condition of the sheep. In addition, in Al Taif Governorate, Kingdom of Saudi Arabia, Degheidy and Al-Qtaibi [45] studied biological control of adult tapeworms (Monizia spp.) by brown algae (Fucus vesiculosus) and their results confirmed the effectiveness of all concentrations, especially 30 µg/ml after one hour.
In the light of our present findings, we conclude that the Spirulina platensis could be a good anthelmintic for moniziasis in sheep. To validate our findings and improve our knowledge on its potential as an anthelmintic drug used for tape worms or in combination of other chemical drug to improve its therapeutic effect more studies are needed.