Abattoir surveillance of Sarcocystis spp., Cysticercosis ovis and Echinococcus granulosus in Tasmanian slaughter sheep, 2007-2013

Prevalence of Taenia ovis (sheep measles) in small ruminants slaughtered by unlicensed butchers in Iraq capital city

This study was aimed at investigating the prevalence of Taenia ovis (sheep measles) in sheep and goats among the unlicensed butcher's settings in Bagdad, Iraq. A total of 1194 sheep comprising 798 males and 396 females were inspected and out of these 41 and 17 (5.1 and 4.2%) were positive of T. ovis respectively. In goat a total of 162 comprising 122 males and 40 females were inspected out of which 39 and 19 (31.9 and 47.5%) were positive for T. ovis for male and female respectively. In this study, the prevalence of T. ovis in sheep of <18 months of age (5.3%) was higher as compared to those in sheep of over 18 months of age (4.9%), the prevalence of T. ovis was higher in male sheep (5.1%) as compared to the female sheep (4.2%). The trend of the prevalence of this parasite in goats was different from what was obtained in sheep, in this case the prevalence was higher in female goats as compared to male goats. Also the prevalence of T. ovis was significantly higher in older goats as compared to younger goats. For the breed the trend was similar to that of sheep where the local breed harbored more of T. ovis as compared to the imported breeds. Our results suggest that the high prevalence of the T. ovis infestations in the unlicensed butcher's settings is of great concern for public health, therefore authorities are to design a preventive program to curtail this problem.

Purification and characterization of cysteine protease of Sarcocystis fusiformis from infected Egyptian water buffaloes

Sarcocystis spp. infects water buffaloes (Bubalus bubalis) causing sarcocystosis. In the present study, Sarcocystis fusiformis was recognized in Egyptian water buffaloes based on histological observation and molecular analysis of internal transcribed spacer 1 (ITS1), 18S ribosomal RNA (18S rRNA) and cytochrome c oxidase subunit I (COX-1) gene fragments. Chemotherapy and vaccines against Sarcocystis spp. could potentially target proteases because they may play a crucial role in the infection. Cysteine proteases are multifunctional enzymes involved in vital metabolic processes. However, the involvement of proteases in S. fusiform infection has not yet been characterized. Here, the purification and study on some biochemical properties of protease isolated from cysts of S. fusiform were carried out. Protease with a molecular weight of 100 kDa was purified. LC-MS/MS analyzed the protein sequence of purified protease and the data suggested that the enzyme might be related to the cysteine protease. The purified protease exhibited maximum activity at pH 6 and a temperature of 50 °C. The Michaelis-Menten constant (Km), the maximum velocity (Vmax), and the turnover number (Kcat) were determined. The complete inhibition effect of cysteine inhibitors indicated that the purified enzyme is a cysteine protease. The results suggested that S. fusiform proteolytic enzyme may be necessary for parasite survival in water buffaloes by digesting host tissues. Therefore, cysteine protease could be a suitable target for vaccinations.

New Insights Into the Prevalence and Phylogenetic Diversity of Cysticercus Ovis Isolates in Sheep from Sulaymaniyah, Iraq

Introduction

Although ovine cysticercosis is not a zoonotic problem, it results in substantial economic losses due to the condemnation of infected tissues or entire carcasses. This study aimed to record preliminary data on the prevalence, and phylogenetic diversity of Cysticercus ovis isolates from slaughtered sheep in the province of Sulaymaniyah, Iraq.

Material and Methods

From January to September 2020, 6, 411 slaughtered sheep were examined for C. ovis by routine meat inspection. The amplification and sequence analysis of the COX1 gene for up to 35 specimens of C. ovis was performed using conventional PCR.

Results

The overall prevalence rate was 1.3%, and the prevalence was significantly higher in older sheep (>1 year) than younger ones (<1 year) (P< 0.05). The cardiac muscle showed a higher tendency to carry C. ovis infection compared to other examined muscles. Sequence analysis of the COX1 gene revealed six haplotypes, and the level of pairwise nucleotide diversity between individual haplotypes was 1–2%. Five out of six of the Taenia ovis haplotypes recovered could have been recorded for the first time globally. Phylogenetic interpretation indicated that all the T. ovis haplotypes clustered in a single clade, and it also indicated an extremely close similarity to Iranian and New Zealand isolates.

Conclusions

Globally, this report adds new data on C. ovis genetic diversity, which provide an extremely useful molecular background with regard to future preventive as well as control strategies.

Taenia ovis in Small Ruminants in Iran: Prevalence, Pathology, and Economic Loss

Taenia ovis larvae can result in economic losses in small ruminants due to condemnation of infected tissues or whole carcasses. From 2017 to 2018, the T. ovis prevalence in 16,180 sheep and 7560 goats at the Najafabad slaughterhouse in Isfahan was determined. More sheep (477; 2.9%) than goats (90; 1.2%) were found to be infected, and the prevalence was higher in animals <1 y (p < 0.0001), and higher in spring in sheep (8.2%) and goats (2.2%). Female sheep were more frequently infected than males (p < 0.0001); this did not hold true for goats. Of the tissues examined, T. ovis was found more often in the heart muscle of sheep compared with other tissues; however, infections in the heart muscle, masseter muscle, diaphragm, and triceps were similar in goats. Granulomas and caseous necrosis in the heart muscles were associated with the accumulation of mononuclear inflammatory cells and the formation of fibrous tissue around the parasite. Based solely on infected tissues found in this study, the economic loss caused by the presence of T. ovis larvae was estimated to be 4167 United States dollars (USD). Control methods, such as proper disposal of infected tissues and anthelmintic treatment of infected dogs, are necessary to decrease infection and prevent economic loss in small ruminants.

Currently Available Monitoring and Surveillance Systems for Taenia spp., Echinococcus spp., Schistosoma spp., and Soil-Transmitted Helminths at the Control/Elimination Stage: A Systematic Review

An increasing global focus on neglected tropical diseases (NTDs) has resulted in the set up of numerous control and elimination activities worldwide. This is partly true for Taenia solium taeniasis/cysticercosis, the most important foodborne parasitic infection. Despite substantial progress, adequate monitoring and surveillance (M&S) are required to sustain a status of control/elimination. This is often lacking, especially for T. solium. Therefore, the objective was to conduct a systematic literature review of the currently available M&S systems at the control/elimination stage of the four top-ranked helminth NTDs. Specifically, Taenia spp., Echinococcus spp., Schistosoma spp., and soil-transmitted helminths (STHs) were considered to determine if there are any similarities between their M&S systems and whether certain approaches can be adopted from each other. The systematic review demonstrated that rigorous M&S systems have been designed for the control/elimination stage of both STHs and schistosomiasis, particularly in China. On the other hand, a concept of M&S for Taenia spp. and Echinococcus spp. has not been fully developed yet, due to a lack of epidemiological data and the fact that many endemic countries are far away from reaching control/elimination. Moreover, accurate diagnostic tools for all four diseases are still imperfect, which complicates proper M&S. Finally, there is an urgent need to develop and harmonize/standardize M&S activities in order to reliably determine and compare the epidemiological situation worldwide.

Cat-dependent diseases cost Australia AU$6 billion per year through impacts on human health and livestock production

Abstract ContextCats are the definitive or primary host for pathogens that cause diseases in people and livestock. These cat-dependent diseases would not occur in Australia if cats had not been introduced, and their ongoing persistence depends on contacts with cats. Toxoplasma gondii is a protozoan parasite that cycles between cats and any other warm-blooded animals. People infected by T. gondii may appear asymptomatic, or have a mild illness, or experience severe, potentially lethal symptoms; the parasite may also affect behaviour and mental health. T. gondii is also a major contributor to spontaneous abortion in sheep and goats. Two species of Sarcocystis, another genus of protozoan parasite, cycle through cats and sheep, causing macroscopic cysts to form in sheep tissues that reduce meat saleability. Toxocara cati, the cat roundworm, causes minor illnesses in humans and livestock, and the bacterium Bartonella henselae causes cat scratch disease, an infection that can be contracted by people when scratched or bitten by cats carrying the pathogen. AimsWe estimated the economic costs of cat-dependent pathogens in Australia. MethodsWe collated national and global data on infection rates, health and production consequences. Key resultsWe estimated the costs of two cat-dependent diseases (toxoplasmosis, cat scratch disease) in people at AU$6.06 billion (plausible range AU$2.11–10.7 billion) annually, and the costs to livestock production from toxoplasmosis and sarcocystosis at AU$11.7 million (plausible range AU$7.67–18.3 million). Most of the human health costs are due to the associations between T. gondii and higher rates of traffic accidents and mental illness in people. The causality behind these associations remains uncertain, so those costs may be overestimated. Conversely, our estimates are incomplete, infections and illness are under-reported or misdiagnosed, and our understanding of disease outcomes is still imperfect, all of which make our costs underestimated. ConclusionsOur analysis suggests that substantial benefits to public health and livestock production could be realised by reducing exposure to cats and breaking parasite transmission cycles. ImplicationsReducing feral cat populations in farming and urban areas, reducing the pet cat population and increasing rates of pet cat containment could help reduce the burden of cat-dependent diseases to people and livestock.

Ultrastructural and Molecular Identification of the sarcocysts of Sarcocystis tenella and Sarcocystis arieticanis Infecting Domestic Sheep (Ovis aries) from Egypt

BACKGROUND

In spite of the global economic significance of sheep production, little is known about the prevalence of various Sarcocystis spp. infecting the domestic sheep (Ovis aries) in Egypt.

MATERIALS AND METHODS

Muscle samples were collected from 175 sheep (> 2 years) slaughtered at El-Mahalla El-Kubra abattoir, Gharbia governorate, Egypt. Samples were initially examined by naked eye for the existence of macrosarcocysts. The microscopic sarcocysts were detected and identified using the light microscopy and the Transmission electron microscopy (TEM). Different microscopic species of ovine Sarcocystis were molecularly confirmed by PCR, sequence analyses and phylogeny.

RESULTS

Preliminary light microscopic inspection of the muscle specimens revealed the existence of only the microscopic sarcocysts of Sarcocystis tenella and Sarcocystis arieticanis in 152 (86.8%) out of the175 examined animals. Sarcoysts of S.tenella had striated thick cyst wall that amounted from 3.5-5.5 μm in thickness whereas, S.arieticanis sarcocysts had a thin cyst wall that ranged from 1-3 μm in thickness. S.tenella sarcocysts were detected in 115 sheep (65.7%), and were more prevalent than those of S.arieticanis, observed only in 68 sheep (38.8%). No macroscopic sarcocysts were observed in any of the examined carcasses. Transmission electron microscopy (TEM) of the cyst wall of S.tenella revealed the existence of the short stubby villar protrusions (VP) with the characteristic disk-like structures at the tips of the (VP). While, TEM of S.arieticanis showed that the cyst wall had elongated tubular protrusions that measured approximately 5-7 μm in length. Each (VP) consisted of a dome-shaped base (0.3-0.9 μm in diameter), a relatively thick middle portion (0.1-0.3 μm) in width, and a thin hair-like distal portion that measured about (0.03 x 1-4.5 μm).

CONCLUSION

Comparative analyses of the sequences of the four genetic markers (18S rRNA, 28S rRNA, mitochondrial cox1 and ITS-1) for S.tenella and S.arieticanis isolates detected herein, revealed genetic variations of 95% and 95- 96% among the different isolates on the level of the 18S rRNA and 28S rRNA, respectively. Whereas, the cox1 and ITS-1 shared sequence identities of 76-78% and 70-73%, respectively. S.tenella was strongly related to S.capracanis infecting goats (Capra hircus). Sequence identity of 98% on the level of 18S rRNA, 28S rRNA genes was observed between the currently identified isolates of S.tenella and the formerly GenBank deposited isolates of S.capracanis. While, cox1 sequences shared identities of 92-93%. Furthermore, S.arieticanis isolates identified here were closely related to the formerly published sequences of S.hircicanis. The 18S rRNA and 28S rRNA sequences of S.arieticanis shared 98% and 94-95% identities with those of S.hircicanis, respectively. However, 87-88% homologies were observed between the cox1 sequences of S.arieticanis and S.hircicanis. Consequently, cox1 and ITS-1 gene sequences act as better genetic markers than 18S rRNA and 28S rRNA sequences for the characterization of ovine Sarcocystis spp. Maximum parsimony analyses based on the sequences of three genetic markers, (18S rRNA, 28S rRNA and mitochondrial cox1), yielded the same placement of the currently identified isolates of the two taxa (S.tenella and S.arieticanis) within a clade of Sarcocystis species with carnivorous animals as known, or assumed, final hosts.

A multi-method and structure-based in silico vaccine designing against Echinococcus granulosus through investigating enolase protein

Introduction: Hydatid disease is a ubiquitous parasitic zoonotic disease, which causes different medical, economic and serious public health problems in some parts of the world. The causal organism is a multi-stage parasite named Echinococcus granulosus whose life cycle is dependent on two types of mammalian hosts viz definitive and intermediate hosts.

Methods: In this study, enolase, as a key functional enzyme in the metabolism of E. granulosus (EgEnolase), was targeted through a comprehensive in silico modeling analysis and designing a host-specific multi-epitope vaccine. Three-dimensional (3D) structure of enolase was modeled using MODELLER v9.18 software. The B-cell epitopes (BEs) were predicted based on the multi-method approach and via some authentic online predictors. ClusPro v2.0 server was used for docking-based T-helper epitope prediction. The 3D structure of the vaccine was modeled using the RaptorX server. The designed vaccine was evaluated for its immunogenicity, physicochemical properties, and allergenicity. The codon optimization of the vaccine sequence was performed based on the codon usage table of E. coli K12. Finally, the energy minimization and molecular docking were implemented for simulating the vaccine binding affinity to the TLR-2 and TLR-4 and the complex stability.

Results: The designed multi-epitope vaccine was found to induce anti-EgEnolase immunity which may have the potential to prevent the survival and proliferation of E. granulosus into the definitive host.

Conclusion: Based on the results, this step-by-step immunoinformatics approach could be considered as a rational platform for designing vaccines against such multi-stage parasites. Furthermore, it is proposed that this multi-epitope vaccine is served as a promising preventive anti-echinococcosis agent.