Economic losses, morpho-molecular identification, and identity of Fasciola species recovered from Egypt

Abstract

A retrospective study to estimate economic losses caused by livers condemnation, due to fascioliasis, of slaughtered cattle and buffaloes in Egypt during the period of 2016-2020, was done. Moreover, a morpho-molecular identification of collected liver flukes from slaughtered animals in municipal abattoirs was conducted. Livers of naturally infected carcasses were obtained from slaughtered animals in Beni-Suef, Cairo and Tanta provinces, Egypt during 2019-2020 for phenotypic characterization of recovered Fasciola species and molecular identification of collected worms using PCR targeting the ITS-1 region. Findings of the retrospective study revealed that percentages of livers condemnation of cattle and buffaloes ranged from 0.79 to 0.66% during the period from 2016 to 2020. The highest percentages were detected in the south Egypt (2.5-6.0%) with the highest economic losses (261850-616300 USD annually). Morphometrically, collected flukes categorized into Fasciola hepatica and Fasciola gigantica. No intermediate forms (Fasciola sp.-like) were detected. Sequencing analysis of ITS-1 PCR products showed that only Fasciola hepatica (26/34) and F. gigantica (8/34) isolates were found, with no intermediate forms, Fasciola sp.-like, could be identified. Currently, Fasciola hepatica was 100% identical with the Egyptian species (LC076196 and JF294998), French species (JF294999), and Iranian species (MF969009 and MK377150). Moreover, the obtained F. gigantica species showed 100% identity with Egyptian ones (LC076125, LC076108 and KX198619), Iranian (KF982047 and MF372919), and other GenBank specimens from Vietnam, Cameroon and India. In conclusion, South Egypt showed the highest economic losses due to fascioliasis, especially Aswan province. Fasciola hepatica was more common than F. gigantica, while the hybrid form was not detected.

Keywords: Egypt; Fasciola gigantica; Fasciola hepatica; ITS-1; Morphometry; PCR; Ruminants.

Fig. 1

A map denoting the distribution pattern of fascioliasis in slaughtered cattle and buffaloes in Egyptian provinces during 2016–2020. The mark filled circle denoted provinces with low prevalences, filled rectangle indicated provinces with moderate prevalences and filled triangle denoted provinces with high prevalences. Among All provinces, Aswan filled star had the highest infection rate. The dark buffaloes symbol referred to the locations of abattoirs

Fig. 2

Some macroscopic and microscopic features of the collected flukes. a Liver from cattle in beni-suef abattoir showing adult Fasciola species. b Numerous Fasciola species from slaughtered animal. c A ventral sucker from adult Fasciola gigantica. d Lateral aspect of adult Fasciola gigantica showing vittiline glands. e The anterior end of adult Fasciola hepatica. f Dimensions of a ventral sucker of adult Fasciola hepatica. Scale bar = 500 µm

Fig. 3

Amplified ITS-1 ribosomal region products on agarose gel. Lane N is a sample treated with saline (negative control). Lane P is a positive control. Lanes 1–23 represented PCR products of amplified Fasciola species specimens (680 bp). Lane 7 represented a negative specimen. Lanes M represented 100 bp ladder

Fig. 4

Nucleotide sequence alignment of ITS-1 of Fasciola species (intermediate form of Vietnam AB514870, and Japan AB514866), F. hepatica Egypt (previous study, LC076196), F. hepaticaof the current study, F. gigantica Egypt (previous study, LC076127), and F. giganticaof the current study

Fig. 5

Phylogenetic relationships between Fasciola hepatica ITS-1 sequences of the current study with other F. hepatica and Fasciola species intermediate form GB isolates using neighbour joining tree. Fasciola hepatica isolates of the current study (OL635617–OL635633), violet square labelled, were closely to each other and previously deposited Egyptian, French and Iranian F. hepatica isolates. The intermediate forms of Fasciola species of previous studies from Egypt, Saudi-Arabia, Vietnam, South-Korea, and Japan were away from isolates of the current study. Paragonimus westermani was used to root the current tree

Fig. 6

Phylogenetic relationships between Fasciola gigantica ITS-1 sequences of the current study with other F. gigantica and Fasciola species intermediate form GB isolates using neighbour joining tree. Fasciola gigantica isolates of the current study (OL635645–OL635648), violet square labelled, were closely to each other and previously deposited Egyptian, Iranian and Nigerian F. gigantica isolates. The intermediate forms of Fasciola species of previous studies from Egypt, Saudi-Arabia, Vietnam, South-Korea, and Japan were away from isolates of the current study. Paragonimus westermani was used to root the current tree