A molecular survey of Echinococcus granulosus sensu lato in central-eastern Europe

Abstract

Open Life Sci. 2016; 11: 524-532 while infections with E. granulosus s.s. which are highly infectious for humans are more commonly encountered in Romania and Hungary.Keywords: Echinococcus granulosus, genotype, DNA sequences, human, pig, central-eastern Europe IntroductionThe larval stages of the tapeworm Echinococcus granulosus sensu lato (s.l.) are the causative agents of cystic echinococcosis (CE), one of the most important cestode infections causing morbidity and mortality in humans and significant economic losses in livestock. Around one million or more people are currently suffering from CE globally and the financial burden of the disease on the livestock industry is substantial, with up to two billion dollars lost annually [1]. Recent molecular phylogenetic analyses have revealed that E. granulosus is a complex of spesies/genotypes with at least five different species: E. granulosus sensu stricto (s.s.) (genotypes G1-G3), Echinococcus equinus (G4), Echinococcus ortleppi (G5), Echinococcus canadensis (G6-G10), and Echinococcus felidis ("lion strain") [2][3][4].CE remains one of the most important helminth zoonoses in many regions of Europe, especially the Mediterranean littoral (Spain, Italy, Greece and Turkey) and southeastern countries such as Bulgaria and Romania. The disease seems to be less prevalent in the UK, Central Europe, the Baltic States and the Scandinavian countries [5,6]. Surveys that addressed the incidence of CE over the last decade from central-eastern Europe has reported a relatively greater incidence in Romania (average incidence annual rate was 0.29 per 100,000 population) and Ukraine (0.30), whereas in Hungary (0.07), Poland (0.08) and Slovakia (0.10) lower numbers of human cases were documented [7]. This also is due to the fact that E. granulosus s.s., which is responsible for the majority Abstract: Central-eastern Europe is an endemic region for cystic echinococcosis where multiple species of intermediate hosts are commonly infected with Echinococcus granulosus sensu lato tapeworms of major medical and veterinary importance. Investigations of the genetic variation of 25 Echinococcus isolates from five countries (Slovakia, Romania, Ukraine, Hungary, Poland) were undertaken using three mitochondrial DNA markers. The 18 isolates from pigs derived from Slovakia and Ukraine and the four human isolates from Slovakia, Poland and Ukraine were identified as E. canadensis G7, whereas the three human isolates from Romania and Hungary were classified as E. granulosus sensu stricto G1. This study reports the first confirmed human case of E. granulosus s.s. in Hungary. The haplotype G7A with two polymorphic sites relative to the most common regional variant of E. canadensis G7 was recorded in both pigs from Ukraine and in a single pig isolate from Slovakia. The results of this study support the circumstantial evidence that E. canadensis G7 with low infectivity for humans is highly prevalent in the northern parts of the region (Poland, Slovakia, forest-steppe zone of Ukraine),

Genetic survey of alveolar and cystic echinococcoses in Romania: first molecular evidence of Echinococcus multilocularis in humans in the country

“…This indicated a substantial role of livestock trade, which has facilitated the parasite dispersal over vast areas, in shaping phylogeographical G1 pattern. In connection with a single human sample identifi ed here as E. granulosus G3, a relatively high proportion of the G3 genotype (28.2 %, 46 of 163 isolates) in the samples typed as E. granulosus s.s. was before detected in Romania when markers with the G1-G3 resolution power were used (Bart et al, 2006;Badaraco et al, 2008;Maillard et al, 2009;Casulli et al, 2012;Mitrea et al, 2014;Šnábel et al, 2016). This genetic form was found in sheep, cattle and pig in the country, whereas the present fi nding provides the fi rst report of G3 in humans from Romania.…”

Cystic echinococcosis in Poland: genetic variability and the first record of Echinococcus granulosus sensu stricto (G1 genotype) in the country

“…Nevertheless, the authors stated that patients may have been infected with E. granulosus s. s. G1 outside Poland (Kazakhstan and Turkey, respectively), and thus they cannot be unambiguously regarded as indigenous. Hydatid cysts recently isolated from a patient in south-eastern Poland had homologous sequences to E. canadensis G7 (Šnábel et al 2016 ). Overall, a total of 62 autochthonous G7 human infections have thus been until now documented in Poland including this study, along with 40 G7 pig infections, one G7 infection in the European beaver and one G1 infection in sheep presently recorded.…”

“…In central and northern Europe, E. granulosus s. s. (G1–G3 complex) is being detected only sporadically. Human autochthonous E. granulosus s. s. cases were recorded in Austria in two patients (Schneider et al 2010 ) and in Hungary in one patient (Šnábel et al 2016 ). In the latter human case originated from Békes county, the microvariant G1A identical to that seen in the present study was detected.…”

A comparative study of different immunoassays to detect specific antibodies to Echinococcus spp. in human sera

“…The somatic antigen of E. multilocularis (AgEm) (Turčeková et al, 2004) was used to determine the presence of antibodies to E. multilocularis. Antibodies to E. granulosus s.l.…”

“…Antibodies to E. granulosus s.l. were detected using antigen B (AgB) prepared according to Reiterová et al (2014) and crude antigens of sheep hydatid fluid (AgHF) prepared according to Turčeková et al (2004), with some modifications. Optimal dilutions for each antigen were based on the results of previous titrations, and the final protein concentration was 2.5 µg.ml -1 for antigens AgEm and AgB, and 5.0 µg.ml -1 for AgHF.…”