Molecular characterization of Echinococcus granulosus of Indian animal isolates on the basis of nuclear and mitochondrial genotype

Phylogenetics and Pathology of Hydatid Disease in Slaughtered Buffaloes of North India

PURPOSE

Hydatid disease is one of the neglected and challenging (for diagnosis as well as for treatment) parasitic diseases. Along with adverse effect on animal's health leading to production losses, hydatidosis is also associated with huge economic losses. The present study was envisaged with an aim to assess the phylogeny and pathological changes due to natural hydatid cysts in lungs and liver of slaughtered buffaloes in north India.

METHODS

A total of 137 slaughtered buffaloes intended for human consumption were screened for the presence of cysts. The retrieved cysts were confirmed molecularly based on the amplification of mitochondrial cytochrome oxidase 1 gene (mtCO1), exhibiting a product size of approximately 446 bp. The samples collected from infected lungs and liver were subjected to histopathological examination.

RESULTS

The hydatid cysts were recorded in 25 (18.2%) animals. Phylogenetic analysis revealed the isolated strain to be closely related to Echinococcus granulosus sensu stricto (G1) genotype. The nucleotide diversity (π) obtained was 0.014685, whereas, Tajima's D was negative (- 2.796053), which indicated purifying selection or recent population expansion. Histopathologically, in the infected lungs, fibrosis and inflammatory reaction comprising of mononuclear cells and fibroblasts around the thick coat of granulation tissue were observed. Marked calcified masses and necrosis were also observed in the calcified cysts. However, in case of infected livers, Kupffer cell hyperplasia, degeneration of hepatocytes, fibrosis and inflammatory cells were most commonly observed around the hydatid cysts.

CONCLUSION

The findings of the present study are of significant veterinary and medical importance owing to economic and public health impact of G1 genotype of E. granulosus.

Prevalence and spatial distribution patterns of human echinococcosis at the township level in Sichuan Province, China

Background

Echinococcosis is a global zoonotic parasitic disease caused by Echinococcus larvae. This disease is highly endemic in Sichuan Province, China. This study investigates the prevalence and spatial distribution characteristics of human echinococcosis at the township level in Sichuan Province, geared towards providing a future reference for the development of precise prevention and control strategies.

Methods

Human prevalence of echinococcosis was evaluated using the B-ultrasonography diagnostic method in Sichuan Province between 2016 and 2019. All data were collected, collated, and analyzed. A spatial distribution map was drawn to intuitively analyze the spatial distribution features. Eventually, the spatial autocorrelation was specified and local indicators of spatial association (LISA) clustering map was drawn to investigate the spatial aggregation of echinococcosis at the township level in Sichuan Province.

Results

The prevalence of echinococcosis in humans of Sichuan Province was 0.462%, among which the occurrence of cystic echinococcosis (CE) was 0.221%, while that of alveolar echinococcosis (AE) was 0.244%. Based on the results of the spatial distribution map, a predominance of echinococcosis in humans decreased gradually from west to east and from north to south. The Global Moran’s I index was 0.77 (Z = 32.07, P < 0.05), indicating that the prevalence of echinococcosis in humans was spatially clustered, exhibiting a significant spatial positive correlation. Further, the findings of local spatial autocorrelation analysis revealed that the “high–high” concentration areas were primarily located in some townships in the northwest of Sichuan Province. However, the “low–low” concentration areas were predominantly located in some townships in the southeast of Sichuan Province.

Conclusions

Our findings demonstrated that the prevalence of echinococcosis in humans of Sichuan Province follows a downward trend, suggesting that the current prevention and control work has achieved substantial outcomes. Nevertheless, the prevalence in humans at the township level is widely distributed and differs significantly, with a clear clustering in space. Therefore, precise prevention and control strategies should be formulated for clusters, specifically strengthening the “high–high” clusters at the township level.

Graphic Abstract

Hydatidosis in slaughtered sheep and goats in India: prevalence, genotypic characterization and pathological studies

The present study determined the prevalence of hydatid cysts in different organs of slaughtered hilly ‘Gaddi’ breed small ruminants—sheep (n = 230) and goats (n = 197)—in Kangra Valley of the north-western Himalayas, India. Hydatid cysts were found in 12.2% (n = 28) of sheep and 10.7% (n = 21) of goats. Pulmonary echinococcosis was more prevalent in slaughtered sheep and goats (sheep 56.36%; goats 62.90%) than hepatic echinococcosis (sheep 43.64%; goats 37.10%). Fertility rates were higher in hepatic (81.25%) and pulmonary cysts of sheep (83.87%) compared to goats. Molecular identification and genotypic characterization of Echinococcus granulosus isolates were based on mitochondrial cytochrome oxidase 1 gene (mtCO1). The genotypic characterization identified the isolated strain to be closely related to the G7 genotype. Histopathological examination revealed a thick coat of granulation tissue, causing fibrosis and inflammatory reaction composed of fibroblasts and mononuclear cells around the cysts. In the liver, hepato-cellular degeneration was prominent at the periphery of the cysts. The present study highlights the molecular confirmation and phylogenetic analysis of E. granulosus isolates with the prevalence of hydatidosis in a naïve host species and in an unexplored region. The findings are of significant medical and veterinary importance regarding development of control measures to check dissemination of hydatidosis.

Cystic echinococcosis in animals and humans of Maharashtra State, India

Echinococcosis/hydatidosis which is a neglected parasitic zoonosis in the developing country like India. The study was conducted during April, 2010 to March, 2017 to determine the prevalence among slaughtered food animals, dogs and human. The samples were collected from the various slaughterhouses situated in different regions of Maharashtra state. A total of 9464 cattle (male), 3661 buffalo, 47189 sheep, 33350 goats and 13579 pigs were scientifically examined during PM inspection at different slaughterhouses. The study revealed that the prevalence of disease in cattle (3.00%) was highest followed by buffalo (2.05%), pig (1.28%), sheep (0.09%) and goat (0.01%), by PM examination. The average estimated economic losses (direct and indirect) due to hydatidosis were Rs. 8,65,83,566 in cattle, Rs. 44,33,93,900 in buffalo, Rs. 7,24,50,615 in sheep, Rs. 1,88,29,359 in goat and Rs. 5,20,49,081 in pigs. Dog faecal samples analyzed and showed the prevalence of echinococcosis as 4.34% (19/438) by sedimentation method and positive samples were confirmed by PCR assay, whereas in high risk human, 11.09% sera samples were found to be positive for echinococcosis. However, based on data collection for seven years, 58 patients were found to be surgically operated for hydatid cyst removal. The results of the present study indicated that cystic echinococcosis/hydatidosis is prevalent in both human and animal population in study areas which attracts serious attention from veterinary and public health authority to reduce economic burden and in designing appropriate strategy for prevention and control of disease.

Global Distribution of Alveolar and Cystic Echinococcosis

Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the diversity and ecology of animal host assemblages and the genetic diversity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.

Molecular and epidemiological updates on cystic echinococcosis infecting water buffaloes from Egypt

Aim:

Cystic echinococcosis (CE) represents a serious parasitic disease at both animal and public health levels. The majority of reports negated the CE infection in buffaloes from Egypt; however, one study illustrated their infection with G6 genotype (camel strain). The present work contributed to update the epidemiological and molecular knowledge about CE infecting this economically important animal for better understanding of its role in maintaining the Echinococcus life cycle.

Materials and Methods:

A total of 120 slaughtered water buffaloes at Mansoura abattoir, Dakahlia province, Egypt, were inspected for the existence of hydatid cysts. Cysts location and fertility were examined. Five out of 27 revealed cysts were tested molecularly using both cytochrome C oxidase subunit 1 and nicotinamide adenine dinucleotide hydrogen subunit 1 (nadh1) genes.

Results:

Low prevalence (4.2%) as well as considerably low fertility rate (14.8%) of buffaloes CE was noted. G1 genotype (common sheep strain) was revealed from the five examined cysts. At the level of nadh1 partial sequences, a globally singleton G1 haplotype was reported.

Conclusion:

This the first report about the G1 infection in buffaloes from Egypt. This study proposed the minimized role of this animal in echinococcosis transmission. These findings could provide preliminary data for the local control of this disease.

Molecular characterization of Echinococcus granulosus cysts in north Indian patients: identification of G1, G3, G5 and G6 genotypes

BACKGROUND

Cystic echinococcosis (CE) caused by the Echinococcus granulosus, is a major public health problem worldwide, including India. The different genotypes of E. granulosus responsible for human hydatidosis have been reported from endemic areas throughout the world. However, the genetic characterization of E. granulosus infecting the human population in India is lacking. The aim of study was to ascertain the genotype(s) of the parasite responsible for human hydatidosis in North India.

METHODOLOGY/PRINCIPAL FINDINGS

To study the transmission patterns of E. granulosus, genotypic analysis was performed on hydatid cysts obtained from 32 cystic echinococcosis (CE) patients residing in 7 different states of North India. Mitochondrial cytochrome c oxidase subunit1 (cox1) sequencing was done for molecular identification of the isolates. Most of the CE patients (30/32) were found to be infected with hydatid cyst of either G3 (53.1%) or G1 (40.62%) genotype and one each of G5 (cattle strain) and G6 (camel strain) genotype.

CONCLUSIONS/SIGNIFICANCE

These findings demonstrate the zoonotic potential of G1 (sheep strain) and G3 (buffalo strain) genotypes of E. granulosus as these emerged as predominant genotypes infecting the humans in India. In addition to this, the present study reports the first human CE case infected with G5 genotype (cattle strain) in an Asian country and presence of G6 genotype (camel strain) in India. The results may have important implications in the planning of control strategies for human hydatidosis.

The molecular phylogenetic signature of Bali cattle revealed by maternal and paternal markers

Bali cattle is a domestic cattle breed that can be found in Malaysia. It is a domestic cattle that was purely derived from a domestication event in Banteng (Bos javanicus) around 3,500 BC in Indonesia. This research was conducted to portray the phylogenetic relationships of the Bali cattle with other cattle species in Malaysia based on maternal and paternal lineage. We analyzed the cytochrome c oxidase I (COI) mitochondrial gene and SRY of Y chromosome obtained from five species of the Bos genus (B. javanicus, Bos gaurus, Bos indicus, Bos taurus, and Bos grunniens). The water buffalo (Bubalus bubalis) was used as an outgroup. The phylogenetic relationships were observed by employing several algorithms: Neighbor-Joining (PAUP version 4.0), Maximum parsimony (PAUP version 4.0) and Bayesian inference (MrBayes 3.1). Results from the maternal data showed that the Bali cattle formed a monophyletic clade, and together with the B. gaurus clade formed a wild cattle clade. Results were supported by high bootstrap and posterior probability values together with genetic distance data. For the paternal lineage, the sequence variation is low (with parsimony informative characters: 2/660) resulting an unresolved Neighbor-Joining tree. However, Bali cattle and other domestic cattle appear in two monophyletic clades distinct from yak, gaur and selembu. This study expresses the potential of the COI gene in portraying the phylogenetic relationships between several Bos species which is important for conservation efforts especially in decision making since cattle is highly bred and hybrid breeds are often formed. Genetic conservation for this high quality beef cattle breed is important by maintaining its genetic characters to prevent extinction or even decreased the genetic quality.

Relative expression of the 14-3-3 gene in different morphotypes of cysts of Echinococcus granulosus isolated from the Indian buffalo

The metacestode stage of Echinococcus granulosus is of zoonotic importance. In general, the 14-3-3 protein is involved in multiplication and survival of eukaryotes. Therefore, this communication presents succinct information on relative expression of the 14-3-3 protein in six different morphotypes of cysts of E. granulosus. All isolated E. granulosus belonged to the common sheep strain (G1). Relative expression of the 14-3-3 protein was higher in fertile cysts when compared to sterile cysts. The predicted amino acid sequence of the 14-3-3 protein was closely clustered with zeta-type isoforms 1 and 2 of the 14-3-3 protein. In addition, the present study demonstrates the presence of the 14-3-3 protein which until now had not been detected in the germinal layer. Our findings indicate that the expression of this biomolecule in the germinal layer of sterile organisms may contribute to the development and survival of the parasite in the host. The uniform expression of actin II conclusively proves the survivability of the harvested organisms.