Cystic Echinococcosis of Camels: 12S rRNA Gene Variation Revealed Changing Pattern of Genetic Diversity Within Echinococcus granulosus sensu lato in the Middle East and North/Sub-Saharan Africa

Genetic diversity of Echinococcus granulosus sensu lato in China: Epidemiological studies and systematic review

Cystic echinococcosis (CE) is a neglected tropical zoonosis caused by Echinococcus granulosus sensu lato (s.l.) and remains a major public health concern globally. Here, CE isolates (n = 3310) with clearly defined genotypes and geographical origins in China were retrieved through our epidemiological survey (2016-2020) and systematic review (1992-2020). Existing known genotypes of Echinococcus granulosus sensu lato (E. granulosus s.l.) except for G4 have been found in China, particularly on the Tibetan Plateau, where their genetic diversity is unique to that part of the world. According to the systematic review, genetic compositions of E. granulosus s.l. in China were as follows: E. granulosus (G1, G3), 98.3%; Echinococcus ortleppi (G5), 0.1%; Echinococcus intermedius (G6, G7), 1.4%; and Echinococcus canadensis (G8, G10), 0.2%. Specifically, G1 was responsible for 97.7% of infections and characterized by the broadest host ranges and geographic distributions. Our epidemiological results showed a relatively stable genetic composition of E. granulosus s.l. in sheep and yaks from three CE hyperendemic provinces (Xinjiang, Sichuan, Qinghai). A higher proportion of fertile cysts were found in sheep (287/406, 70.7%) than in yaks (28/184, 15.2%). During the past 29 years, 51 cox1 haplotypes of E. granulosus s.l. were endemic in China. The ancestral haplotype (Hap_2) remained the most common haplotype, 12 relatively common haplotypes were endemic and nine newly reported haplotypes were found during the survey. Overall, our results demonstrate that the compulsory immunization of sheep and the pilot EG95 vaccination campaign in yaks are well matched with the current genotypic situation. In addition to yaks, we advocate for more surveillance of CE isolates from pigs, cattle, goats and camels, since their roles in the transmission and reservation of E. granulosus s.l. have been largely ignored in China.

Copro-Molecular Identification of Tapeworms in Introduced Invasive Carnivores in Poland

The raccoon (Procyon lotor) and the raccoon dog (Nyctereutes procyonoides) were introduced to Europe and, in the past decades, their populations have increased and adapted to synanthropic environments across Europe. In view of their possible further spread in Europe, the invasive species should be examined as potential reservoirs for helminths, including tapeworms. This study aims to investigate the prevalence and diversity of tapeworms in introduced wild carnivores in Poland by identifying cestode species based on copro-DNA analysis. A total of 214 individual fecal samples from non-native invasive carnivores, i.e., raccoons and raccoon dogs, and additionally 47 samples from native carnivores, i.e., European badgers (Meles meles), were analyzed for the presence of cestodes. PCR analysis of fecal samples targeting a fragment of mitochondrial (mt) 12S rRNA gene revealed the presence of cestode DNA in 19 of 103 (18.4%) raccoons, in 13 of 111 (11.7%) raccoon dogs and in 23 of 47 (48.9%) badgers. Sequence analysis demonstrated the presence of Mesocestoides litteratus in raccoons and raccoon dogs, while Mesocestoides lineatus was identified only in two samples derived from raccoon dogs. Moreover, in this study, Atriotaenia incisa was for the first time molecularly characterized by using fragments of mt 12S rRNA gene, and the DNA of this cestode species was detected in the fecal samples of all the examined host species.

Three species of Echinococcus granulosus sensu lato infect camels on the Arabian Peninsula

We report on the genetic identity of 36 Echinococcus cysts that were collected during a recent slaughterhouse survey of 810 locally bred camels (dromedaries) in the Eastern Province of the Kingdom of Saudi Arabia. Analysis of a partial nad1 gene sequence showed that the majority (n = 29) belonged to E. granulosus sensu stricto, four to E. canadensis G6/7, and three to E. ortleppi. Eight of the 29 E. granulosus s.s. cysts contained protoscoleces; all other cysts were calcified and non-viable. This is the first report of the presence E. ortleppi from the Arabian Peninsula, a parasite that is typically transmitted via cattle. The results indicate widespread infection of camels with CE in eastern Saudi Arabia and an active role of camels in the lifecycles of at least E. granulosus s.s.. Complete cox1 haplotype analysis of 21 E. granulosus s.s. isolates shows that the majority of variants circulating in eastern Saudi Arabia is distinct from but closely related to haplotypes from neighboring countries in the Middle East, which indicates the presence of this parasite in KSA for a longer period of time. All isolates of E. granulosus s.s. in this study belonged to the G1 cluster, although the G3 genotype has previously also been reported from the Middle East.