High genetic diversity of Echinococcus canadensis G10 in northeastern Asia: is it the region of origin?

Echinococcus canadensis consists of 4 genotypes: G6, G7, G8 and G10. While the first 2 predominantly infect domestic animals, the latter are sylvatic in nature involving mainly wolves and cervids as hosts and can be found in the northern temperate to Arctic latitudes. This circumstance makes the acquisition of sample material difficult, and little information is known about their genetic structure. The majority of specimens analysed to date have been from the European region, comparatively few from northeast Asia and Alaska. In the current study, Echinococcus spp. from wolves and intermediate hosts from the Republic of Sakha in eastern Russia were examined. Echinococcus canadensis G10 was identified in 15 wolves and 4 cervid intermediate hosts. Complete mitochondrial cytochrome c oxidase subunit 1 (cox1) sequences were obtained from 42 worm and cyst specimens from Sakha and, for comparison, from an additional 13 G10 cysts from Finland. For comparative analyses of the genetic diversity of G10 of European and Asian origin, all available cox1 sequences from GenBank were included, increasing the number of sequences to 99. The diversity found in northeast Asia was by far higher than in Europe, suggesting that the geographic origin of E. canadensis (at least of G10) might be northeast Asia.

Prevalence of Gastrointestinal Parasites in Pigs: A Preliminary Study in Tolon and Kumbungu Districts, Ghana

Pigs are important livestock that contribute to the economy and food security of Ghana, but the productivity of the sector is hindered by factors such as parasitic disease infections. Here, we detected the prevalence and polyparasitism of gastrointestinal parasites in pigs from selected farms in the Tolon and Kumbungu districts. Faeces of the animals were screened for parasite eggs using the sedimentation and flotation methods. From 56 pigs screened, 91.1% (CI = 95%; χ2 = 0.212) of them had parasitic infections, and affected pigs harboured 1-5 distinct parasites with the most occurring being Strongyloides ransomi (46.43%). Other parasites identified included Hyostrongylusrubidus, Ascaris suum, Trichuris suis, Physocephalus sexalatus, and Coccidia, among others. Parasitism was more frequent in pigs under 2 years (94%) than older ones (66.67%). The high prevalence of GI parasites was attributed to poor husbandry practices and inadequate of veterinary care for the animals. The situation can be improved by farmer education on good husbandry practices and regular deworming of pigs.

Cystic echinococcosis of ruminant livestock in Namibia

Cystic echinococcosis (CE) is widespread and locally frequent in southern Africa where it affects humans, livestock, and wild mammals. However, most data from the region are old and do not provide information on the causative Echinococcus species. For Namibian livestock only anecdotal records were available prior to this preliminary survey. Our retrospective analysis of slaughterhouse records of CE in cattle from the commercial farming area in central and southern Namibia resulted in 1.65% CE prevalence among 35,143 slaughtered cattle in the period 2015-2016. For comparison, carcasses of ruminant livestock were prospectively examined in the communal farming areas of northern Namibia, resulting in three CE cases among only 12 cattle, and no cases among nine goats. To determine the Echinococcus species affecting Namibian livestock, a total of 53 cysts were collected from all parts of the country and analysed for species and genotype by amplification and sequencing of the nad1 gene. All 50 cattle cysts (isolated from 40 cattle), both from the commercial and communal farming areas, were Echinococcus ortleppi (all fertile, and 42/50 from the lungs), while three opportunistically collected cysts from three sheep in southern Namibia were E. canadensis G7. Our data suggest that E. ortleppi is the only CE agent that is relevant for cattle infection in Namibia, and that low prevalence in the commercial farming areas contrasts with high CE burden in the northern traditional husbandry systems. The present data provide baseline information to stimulate epidemiological studies on the transmission pathways of various CE agents in livestock, wildlife, and humans in Namibia and neighbouring countries.

Genetic characterization and antimicrobial susceptibility of Escherichia coli isolated from household water sources in northern Ghana

The microbial quality of household water is an important issue in developing countries, especially in Ghana, where many people still depend on unimproved sources of water. The present study investigated the prevalence, genetic characteristics, and antimicrobial resistance profile of Escherichia coli from surface water sources. Fifty-two water samples were analyzed by using a spread plate, a biochemical test, and multiplex polymerase chain reactions. E. coli was isolated from each of the 52 water samples. Of these isolates, 75% were noted to possess virulence genes. Approximately 54% of the isolates were characterized as follows: enterotoxigenic E. coli (ETEC, 10.26%), enteropathogenic E. coli (EPEC, 17.95%), verotoxigenic E. coli (VTEC, 23.07%), and enteroinvasive E. coli (EIEC, 2.57%). Eighteen of the fifty-two isolates could not be characterized due to heterogeneity in banding. The disc diffusion method was used to test for antimicrobial susceptibility. The isolates were most resistant to ceftazidime, augmentin, and cefuroxime. Multidrug resistance was recorded in 48.1% of the isolates. In contrast, the isolates were most susceptible to ciprofloxacin (86.5%), nitrofurantoin (84.6%), and ofloxacin (75%). These results revealed a high diversity and widespread of E. coli in northern Ghana. The study provides important data for public health nationwide surveillance of E. coli in surface water across the country.

Prevalence and genetic variance of Taenia hydatigena in goats and sheep from northern Ghana: Preliminary data on a globally neglected livestock parasite

Cysticercosis caused by the larval stages of Taenia hydatigena has a significant global impact on livestock production, particularly of goats and sheep. Despite this, global data on prevalence and genetic variance of this parasite are still scarce. In Ghana, as in most African countries, numerous anecdotal observations agree that it is widespread and frequent. To obtain baseline data, we screened 251 goats and 248 sheep in northern Ghana (Upper East Region) for T. hydatigena metacestode and molecularly characterized the isolates using the mtDNA cox1 gene sequence. Prevalence was 58.57% in goats and 60.48% in sheep, confirming the abundance of this parasite in the region. Gene sequences revealed high diversity (π 0.00346, hd 0.809) and significant negative Tajima D and Fu's Fs values, a characteristic of a population experiencing an expansion after a recent bottleneck. This is the first account of the genetic structure of T. hydatigena in Ghana, intended as a basis for subsequent studies in the region.

Ascaridia galli and Heterakis gallinarum prevalence and genetic variance of A. galli in rural chicken from the Northern Region, Ghana

Rural chicken production in Ghana is predominantly done under the extensive system that exposes birds to parasitic infections. We investigated the prevalence of Ascaridia spp. and Heterakis spp. and as a preliminary study characterized the genetic variance of the Ascaridia galli isolates from rural chicken in Kumbungu, Savelugu and Tolon Districts in the Northern Region, Ghana. A total of 86 chickens aged 6-10 weeks were dissected and GIT inspected for nematodes. Nematode were described based on morphological features to be A. galli and H. gallinarum. Additionally, the mitochondrial cox1 gene (475 bp) of Ascaridia isolates was amplified and sequenced. The overall prevalence of nematodes was 47.67%: A. galli 37.21% and H. gallinarum 20.93%. Prevalence values of A. galli in the Kumbungu, Savelugu and Tolon Districts were 25.00%, 36.00%, 56.00%, respectively, and that of H. gallinarum, respectively were 16.67%, 28.00% and 20.00%. A Chi-square test (x² = 6.0907, p < 0.048) showed an association of A. galli prevalence to the district of origin of birds. From 20 A. galli cox1 sequences analyzed, all sequences were identified as A. galli. Two haplotypes were recorded, namely, GHA1 and GHA2. Haplotype GHA1 was found to have wide distribution globally, whereas GHA2 appear to be novel in the present study. The data shows the importance of A. galli and H. gallinarum infection in rural chicken in northern Ghana and pave way for further epidemiological study of avian nematodes.

Taenia hydatigena in goat and sheep in Ghana: a cross-sectional abattoir survey in Northern and Upper West Regions

Parasitic infections are a major setback to livestock production in Ghana but the disease situation in many localities is poorly understood. A study to determine the prevalence and distribution of Taenia hydatigena in goats and sheep was carried out in two major municipal abattoirs in Tamale and Wa. A total of 538 goats and 256 sheep were screened for cysts during a cross-sectional survey which revealed a prevalence of 22.34% and 33.96% in goats from Tamale and Wa, respectively, and 22.66% in sheep from Tamale. Infection was common in male and female, young and old animals alike. Animals considered in the study originated from various localities within Northern and Upper West Regions and T. hydatigena infection was thought to be autochthonous, depicting a wide distribution of the cestode infection in small ruminants. Our data represent the importance of T. hydatigena infection in goat and sheep production and provide a base for subsequent epidemiological studies in Ghana.

Dicrocoelium spp. in cattle from Wa, Ghana: prevalence and phylogeny based on 28S rRNA

Dicrocoeliosis is a trematode infection in cattle, sheep and goats caused by the small liver fluke, Dicrocoelium spp. Though endemic in Ghana, its disease situation is poorly understood. In the present study, the prevalence, distribution and worm load of Dicrocoelium spp. in cattle at slaughter in Wa were determined. A total of 389 cattle were screened during meat inspection for liver flukes, and polymerase chain reaction accompanied by DNA sequencing of the 28S rRNA gene was used to identify Dicrocoelium spp. Generally, prevalence of bovine dicrocoeliosis (small liver fluke) stood at 19.54 % with prevalence in males and females being 17.62 % and 21.43 %, respectively. Animals under 2 years suffered more infection than older ones (23.08 % vs. 16.80 %). Dicrocoelium infection was recorded in animals from all the communities where slaughtered cattle came from. On average, 31 flukes per infected animal were recorded. A molecular confirmatory test on seven flukes identified them as D. hospes. This preliminary study highlights the importance of bovine dicrocoeliosis in Ghana and has identified D. hospes as a causal agent. The data provides basis for further studies to appraise the trematode disease situation in animals and phylogeny of Dicrocoelium spp. circulating in Ghana.

Echinococcus ortleppi and Echinococcus canadensis G6/7 affect domestic animals in western Zambia

Cystic echinococcosis (CE) is endemic in many parts of sub-Saharan Africa. In contrast to the eastern part of the continent, very little data exists on the current disease situation in southern Africa including Zambia. This study determined frequency and species identity of Echinococcus spp. circulating in livestock and dogs in the Western Province of Zambia. Cysts were collected in slaughterhouses at meat inspection (cattle) and during examination of home slaughtered pigs, while dog faecal samples were collected per-rectum and examined microscopically for the presence of taeniid eggs. Individual taeniid eggs from faecal samples and individual protoscoleces from cysts were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and/or sequencing of the NADH-dehydrogenase subunit 1 (nad1) and cytochrome C oxidase 1 (cox1) gene. Fifty-four of 2000 cattle (2.7%) were found infected with a total of 65 cysts, predominantly fertile lungs cysts; all cysts were identified as Echinococcus ortleppi. Two out of 52 home-slaughtered pigs (3.8%) were infected with a fertile lung cyst each; both cysts were also identified as E. ortleppi. Microscopic examination revealed 10/289 dog faecal samples to contain taeniid eggs, of which four samples (two each) contained Echinococcus canadensis (G6/7) or Taenia hydatigena, respectively. This is the first insight in the Echinococcus species circulating in Zambia providing premises for further studies into transmission dynamics of CE in the southern African region.

Genetic characterization of Echinococcus species in eastern Ethiopia

Cystic echinococcosis (CE) is a neglected zoonotic disease with considerable economic and public health burden worldwide, particularly affecting developing countries like Ethiopia. To initiate effective prevention and control of CE, comprehensive data on the local lifecycles of the various species/genotypes of Echinococcus are needed. In the present study, conducted in eastern Ethiopia, a total of 1106 livestock animals were examined at three slaughterhouses, which resulted in combined prevalence of morphologically and molecularly confirmed CE of 8.4% (75/891) in cattle, 1.1% (1/95) in sheep, 0.0% (0/95) in goats and 12.0% (3/25) in camels. All cystic lesions recovered during post mortem examination were assessed for cyst condition and underwent molecular characterization by PCR and sequencing of a 1081 bp fragment of the mitochondrial cox1 gene. A total of 175 cysts belonged to E. granulosus s.s. (n = 165), E. ortleppi (n = 6) and E. canadensis G6/7 (n = 4). Of all examined cysts, only 14 were fertile and contained protoscoleces, all from the lungs of cattle: 5 were E. granulosus s.s., 6 E. ortleppi and 3 E. canadensis G6/7. In sheep, only one sterile liver cyst of E. granulosus s.s. was found, while in camels seven sterile or caseated/calcified cysts of E. granulosus s.s. and E. canadensis G6/7 were found in liver and lungs. In conclusion, the prevalence of CE was rather low compared to other regions of Ethiopia, and, based on the number of fertile cysts, three Echinococcus spp. contributed almost equally to transmission. Cattle seem to be, epidemiologically, the most important livestock species. Our data provide a substantial basis for more detailed investigations of the transmission dynamics of CE in the study area.

Fasciola spp. in Armenia: Genetic diversity in a global context

Fasciolosis, a food- and waterborne infection caused by the trematodes Fasciola hepatica and F. gigantica, is recognized by WHO as a neglected zoonotic disease. Whereas F. hepatica is distributed worldwide in cooler climates, F. gigantica occurs mainly in the tropics of Africa and Asia. The southern Caucasus, with Armenia, is one of the most northern regions where both species occur and may produce hybrids. In this study, livestock in central Armenia was surveyed for fasciolosis, the causative species were determined and the genetic diversity of both species was estimated. Total prevalence in sheep (1794), cattle (324) and goats (9) was 21.2%, 15.7% and 44.4%, respectively. After morphological identification and sequencing of a mitochondrial (nad1) and a nuclear marker gene (28S rRNA), 62 collected specimens were allocated to F. hepatica (n = 55) and F. gigantica (n = 7). Intraspecific diversity was evaluated for the complete nad1 gene, resulting in 29 haplotypes of F. hepatica and six haplotypes of F. gigantica. Diversity was higher among F. gigantica than F. hepatica in the Armenian sample set, a difference that was confirmed analyzing available sequences for both species worldwide. Maximum genetic distance between haplotypes in global networks was 49 nucleotide steps for F. gigantica compared to 15 for F. hepatica. In the available sample sets, F. hepatica showed higher diversity in western Asia and the Middle East compared to Europe and eastern Asia, while for F. gigantica loosely structured clusters comprising mainly western/southern Asian and African haplotypes could be identified. A distinct clade comprising haplotypes from Zambia was basal in the phylogenetic tree. Biogeographical implications of these data are discussed.

Genetic differentiation of the G6/7 cluster of Echinococcus canadensis based on mitochondrial marker genes

Among the genotype/species causing cystic echinococcosis, the taxonomic status of Echinococcus canadensis is only partially resolved. Within E. canadensis, four genotypes (G6, G7, G8 and G10) have been described based on short mitochondrial sequences, of which G6 and G7 (the 'camel' and the 'pig' strain, respectively) are closely related and variously regarded as microvariants of a single strain G6/7. Globally, this G6/7 cluster is the second most important agent of human cystic echinococcosis and is the predominant Echinococcus taxon in large parts of sub-Saharan Africa. To add data on the internal structure and the geographical distribution of this cluster, we analysed diversity and population structure of 296 isolates of E. canadensis from sub-Saharan Africa, the Middle East and Europe using the complete mitochondrial cytochrome c oxidase subunit 1 (cox1) (1,608bp) and NADH dehydrogenase subunit 1 (nad1) (894bp) gene sequences. Polymorphism of the mtDNA loci gave 51 (cox1), 33 (nad1) and 73 (cox1-nad1 concatenated) haplotypes. African and Middle Eastern isolates mainly grouped in a star-like structure around a predominant haplotype, while the European isolates produced more diversified networks. Although the cox1 diagnostic sequence for G6 is frequent in the African/Middle Eastern sub-cluster, and that for G7 is common in the European isolates, numerous intermediate variants prevent a clear distinction into 'G6' or 'G7', and the entire taxon is best treated as a common haplotype cluster G6/7. Meanwhile, the G6/7 cluster is clearly distinct from sequences of wildlife isolates of G8 and G10 from the northern hemisphere, and sequences of the latter genotypes were remarkably distant from each other. It is clear from the present study that, based on mitochondrial data, G6/7 is a coherent genotypic entity within E. canadensis that retains substantial intraspecific variance, and sub-populations share common ancestral polymorphisms and haplotypes. This study provides the basis for wider biogeographic comparison and population genetics studies of this taxon.