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5,589 result(s) for "Cattle - parasitology"
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Bovine cryptosporidiosis: impact, host-parasite interaction and control strategies
Gastrointestinal disease caused by the apicomplexan parasite Cryptosporidium parvum is one of the most important diseases of young ruminant livestock, particularly neonatal calves. Infected animals may suffer from profuse watery diarrhoea, dehydration and in severe cases death can occur. At present, effective therapeutic and preventative measures are not available and a better understanding of the host–pathogen interactions is required. Cryptosporidium parvum is also an important zoonotic pathogen causing severe disease in people, with young children being particularly vulnerable. Our knowledge of the immune responses induced by Cryptosporidium parasites in clinically relevant hosts is very limited. This review discusses the impact of bovine cryptosporidiosis and describes how a thorough understanding of the host–pathogen interactions may help to identify novel prevention and control strategies.
Exploring the Gastrointestinal “Nemabiome”: Deep Amplicon Sequencing to Quantify the Species Composition of Parasitic Nematode Communities
Parasitic helminth infections have a considerable impact on global human health as well as animal welfare and production. Although co-infection with multiple parasite species within a host is common, there is a dearth of tools with which to study the composition of these complex parasite communities. Helminth species vary in their pathogenicity, epidemiology and drug sensitivity and the interactions that occur between co-infecting species and their hosts are poorly understood. We describe the first application of deep amplicon sequencing to study parasitic nematode communities as well as introduce the concept of the gastro-intestinal \"nemabiome\". The approach is analogous to 16S rDNA deep sequencing used to explore microbial communities, but utilizes the nematode ITS-2 rDNA locus instead. Gastro-intestinal parasites of cattle were used to develop the concept, as this host has many well-defined gastro-intestinal nematode species that commonly occur as complex co-infections. Further, the availability of pure mono-parasite populations from experimentally infected cattle allowed us to prepare mock parasite communities to determine, and correct for, species representation biases in the sequence data. We demonstrate that, once these biases have been corrected, accurate relative quantitation of gastro-intestinal parasitic nematode communities in cattle fecal samples can be achieved. We have validated the accuracy of the method applied to field-samples by comparing the results of detailed morphological examination of L3 larvae populations with those of the sequencing assay. The results illustrate the insights that can be gained into the species composition of parasite communities, using grazing cattle in the mid-west USA as an example. However, both the technical approach and the concept of the 'nemabiome' have a wide range of potential applications in human and veterinary medicine. These include investigations of host-parasite and parasite-parasite interactions during co-infection, parasite epidemiology, parasite ecology and the response of parasite populations to both drug treatments and control programs.
Nationwide investigation of eukaryotic pathogens in ticks from cattle and sheep in Kyrgyzstan using metabarcoding
Ticks are significant vectors of bacterial, viral, and protozoan pathogens, impacting both public health and agriculture. In Kyrgyzstan, tick-borne diseases are a growing concern for livestock and human health. While bacterial and viral pathogens are widely studied, and limited previous investigations have focused on specific Babesia and Theileria species in certain host animals, comprehensive data on tick eukaryotic microbiota and potential pathogens across diverse hosts nationwide is scarce. To address this gap, our study provides the comprehensive nationwide assessment of the potential protozoan pathogens in ticks from cattle and sheep, analyzing data of Babesia and Theileria at the genus level. We collected 472 tick samples from cattle and sheep across seven regions of Kyrgyzstan (March-July 2022). Tick species were identified via microscope and Sanger sequencing (mitochondrial COI gene). Eukaryotic microbiota was analyzed using 18S rRNA V9 NGS. Sanger sequencing identified five genera and 11 tick species. NGS analysis revealed Babesia (13.3%) and Theileria (12.7%) as among the most prevalent protozoa detected at the genus level. Babesia was significantly more prevalent in nymph-stage ticks and those collected from sheep, whereas Theileria was detected across a broader range of tick species and host animals, showing less variation across life stages. No significant differences in prevalence were observed based on tick sex or the number of hosts in the tick life cycle. Regionally, Babesia detection was highest in the Osh region, particularly in ticks collected from both cattle and sheep. This is the first comprehensive nationwide analysis of tick eukaryotic metabarcoding study in Kyrgyzstan focusing on pathogenic protozoa detected at the genus level. Findings provide crucial baseline data on Babesia and Theileria geographic and host-specific prevalence. Understanding these information is essential for advancing future research and supporting the development of effective surveillance and control strategies against babesiosis and theileriosis in regional livestock.
Molecular characterization of Rhipicephalus microplus and Haemaphysalis bispinosa ticks from cattle across Thailand: Regional identification and evidence of different genetic sub-structures between mainland and peninsular populations
Phylogenetic and population genetic analyses were conducted on tick specimens collected from cattle in northern, northeastern, central, and southern regions of Thailand. Morphological identification indicated these ticks consisted of three species, Rhipicephalus microplus from all four regions, R. sanguineus from the northern and northeastern regions, and a Haemaphysalis species only collected from the northeastern region. Analysis of cytochrome c oxidase subunit I gene ( COI ) sequences identified R. microplus clades A and C, while clade B was not detected in this study. The same analysis indicated specimens morphologically identified as Haemaphysalis were H. bispinosa, confirming previous reports of their prevalence in northeastern Thailand. H. bispinosa showed low haplotype and nucleotide diversity, suggesting either a bottleneck or founder effect. Both R. microplus clades displayed high haplotype diversity and low nucleotide diversity, a pattern associated with population expansion. Genetic structural analysis revealed significant genetic differences in R. microplus clade A, especially between mainland (northern, northeastern, and central regions) and peninsular (southern region) populations, which indicated limited gene flow between these areas while suggesting movement of these ticks across the mainland. The sequence analyses described in this report enhance understanding of the natural history of ticks in Thailand and are expected to guide and strengthen tick control strategies across Southeast Asia.
Zoonotic Cryptosporidium Species in Animals Inhabiting Sydney Water Catchments
Cryptosporidium is one of the most common zoonotic waterborne parasitic diseases worldwide and represents a major public health concern of water utilities in developed nations. As animals in catchments can shed human-infectious Cryptosporidium oocysts, determining the potential role of animals in dissemination of zoonotic Cryptosporidium to drinking water sources is crucial. In the present study, a total of 952 animal faecal samples from four dominant species (kangaroos, rabbits, cattle and sheep) inhabiting Sydney's drinking water catchments were screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) and positives sequenced at multiple loci. Cryptosporidium species were detected in 3.6% (21/576) of kangaroos, 7.0% (10/142) of cattle, 2.3% (3/128) of sheep and 13.2% (14/106) of rabbit samples screened. Sequence analysis of a region of the 18S rRNA locus identified C. macropodum and C. hominis in 4 and 17 isolates from kangaroos respectively, C. hominis and C. parvum in 6 and 4 isolates respectively each from cattle, C. ubiquitum in 3 isolates from sheep and C. cuniculus in 14 isolates from rabbits. All the Cryptosporidium species identified were zoonotic species with the exception of C. macropodum. Subtyping using the 5' half of gp60 identified C. hominis IbA10G2 (n = 12) and IdA15G1 (n = 2) in kangaroo faecal samples; C. hominis IbA10G2 (n = 4) and C. parvum IIaA18G3R1 (n = 4) in cattle faecal samples, C. ubiquitum subtype XIIa (n = 1) in sheep and C. cuniculus VbA23 (n = 9) in rabbits. Additional analysis of a subset of samples using primers targeting conserved regions of the MIC1 gene and the 3' end of gp60 suggests that the C. hominis detected in these animals represent substantial variants that failed to amplify as expected. The significance of this finding requires further investigation but might be reflective of the ability of this C. hominis variant to infect animals. The finding of zoonotic Cryptosporidium species in these animals may have important implications for the management of drinking water catchments to minimize risk to public health.
Coinfection affects the phenotypic but not genetic resistance of cattle to common parasites
Background Genetic variation in host resistance to individual parasites is well documented in cattle; however, the influence of coinfection on these genetic responses to selection remains poorly characterized. In particular, it is unclear how concurrent exposure to multiple parasite species alters phenotypic expression, heritability estimates, or genetic correlations between resistance traits. To address these gaps, we evaluated the impact of coinfection on the genetic architecture of parasite resistance in yearling Nellore calves naturally challenged with ectoparasites (ticks) and endoparasites (gastrointestinal nematodes and Eimeria spp.). Using longitudinal parasite count data, we estimated genetic parameters and examined how coinfection modifies both individual parasite resistance and the genetic correlations among traits. Results Our results confirmed that coinfection is a common phenomenon (almost ¾ of samples contained multiple parasites) and that resistance to individual parasites is a heritable trait. Furthermore, coinfection with Eimeria spp. reduced the phenotypic resistance to nematodes, and vice versa. We observed diverse genetic associations for resistance to different parasites, including positive, negative, and nonsignificant correlations. Notably, coinfection had no significant effect on genetic resistance to individual parasites, nor did it alter genetic variances or associations between resistance to different parasites. Conclusions While coinfection may influence the outcomes of nongenetic parasite control programs, its impact on genetic control strategies appears minimal. In other words, genetic resistance of Nellore cattle to three key parasite species appears to be robust and unaffected by the presence of coinfection.
Mapping QTL influencing gastrointestinal nematode burden in Dutch Holstein-Friesian dairy cattle
Background Parasitic gastroenteritis caused by nematodes is only second to mastitis in terms of health costs to dairy farmers in developed countries. Sustainable control strategies complementing anthelmintics are desired, including selective breeding for enhanced resistance. Results and Conclusion To quantify and characterize the genetic contribution to variation in resistance to gastro-intestinal parasites, we measured the heritability of faecal egg and larval counts in the Dutch Holstein-Friesian dairy cattle population. The heritability of faecal egg counts ranged from 7 to 21% and was generally higher than for larval counts. We performed a whole genome scan in 12 paternal half-daughter groups for a total of 768 cows, corresponding to the ~10% most and least infected daughters within each family (selective genotyping). Two genome-wide significant QTL were identified in an across-family analysis, respectively on chromosomes 9 and 19, coinciding with previous findings in orthologous chromosomal regions in sheep. We identified six more suggestive QTL by within-family analysis. An additional 73 informative SNPs were genotyped on chromosome 19 and the ensuing high density map used in a variance component approach to simultaneously exploit linkage and linkage disequilibrium in an initial inconclusive attempt to refine the QTL map position.
A transcriptome and proteome of the tick Rhipicephalus microplus shaped by the genetic composition of its hosts and developmental stage
The cattle tick, Rhipicephalus microplus , is a monoxenous tick that co-evolved with indicine cattle on the Indian subcontinent. It causes massive damage to livestock worldwide. Cattle breeds present heritable, contrasting phenotypes of tick loads, taurine breeds carrying higher loads of the parasite than indicine breeds. Thus, a useful model is available to analyze mechanisms that determine outcomes of parasitism. We sought to gain insights on these mechanisms and used RNA sequencing and Multidimensional Protein Identification Technology (MudPIT) to generate a transcriptome from whole larvae and salivary glands from nymphs, males and females feeding on genetically susceptible and resistant bovine hosts and their corresponding proteomes. 931,698 reads were annotated into 11,676 coding sequences (CDS), which were manually curated into 116 different protein families. Male ticks presented the most diverse armamentarium of mediators of parasitism. In addition, levels of expression of many genes encoding mediators of parasitism were significantly associated with the level and stage of host immunity and/or were temporally restricted to developmental stages of the tick. These insights should assist in developing novel, sustainable technologies for tick control.
A review of bovine fasciolosis and other trematode infections in Nigeria
Trematode infections cause serious economic losses to livestock worldwide. Global production losses due to fasciolosis alone exceed US$3 billion annually. Many trematode infections are also zoonotic and thus a public health concern. The World Health Organization has estimated that about 56 million people worldwide are infected by at least one zoonotic trematode species, and up to 750 million people are at risk of infection. Fasciolosis caused by the fluke Fasciola gigantica is endemic in Nigeria and is one of the most common causes of liver condemnation in abattoirs. Total cattle losses from Fasciola infection in Nigeria have been estimated to cost £32.5 million. Other trematode infections of cattle, including paramphistomosis, dicrocoeliasis and schistosomiasis, have all been reported in various parts of Nigeria, with varying prevalence. Most publications on trematode infections are limited to Nigerian local and national journals, with very few international reports. This paper therefore summarized the current data on distribution, control and zoonotic trematode infections in Nigeria and other African countries. We also identified research gaps and made recommendations for future research and areas for funding for policy/planning.
Echinococcus granulosus hydatid cyst location is modified by Fasciola hepatica infection in cattle
Background Natural parasite infection occurs in wild and domestics animals with more than one parasite species at the same time, generating an infection called polyparasitism. Cystic echinococcosis reports are usually based only on infection with Echinoccocus granulosus leaving aside other internal parasitoses that could modulate both the immune response and pathogenesis of the natural infection. Fasciola hepatica is another cosmopolitan parasite in ruminants with a similar distribution to E. granulosus in different parts of the world, but no information of the effect of co-infection with E. granulosus has been described. The aims of this report were to establish E. granulosus prevalence and explore the association of F. hepatica co-infection and natural E. granulosus infections in cattle. Results From 1725 animals, the prevalence of E. granulosus and F. hepatica was 21.16 and 51.3%, respectively. Considering both infections, older cattle (> 4 years) presented higher prevalence compared to younger animals. In E. granulosus -infected cattle, 5.21% had fertile cysts, 71.78% infertile cysts, and in 23.01% cysts were smaller than 1 cm in diameter. Considering cyst location, 39.72% had lungs cysts, 24.72% had liver cysts and 36.94% had cysts in both organs. Cyst location significantly differed between age groups: 44.68% of younger animals had cysts only in the lungs, while older animals presented hydatid cyst in the lungs and liver simultaneously (44.15%). With E. granulosus infection alone, 30.26% of cysts were found in the lungs, 31.79% in the liver and 37.95% in both organs. Regarding the co-infection of E. granulosus with F. hepatica , the proportion was significantly different ( P  < 0.05) with most animals having cysts only in the lungs (49.41%) and a lower level of liver infection (15.88%). Analyzing organ cyst distribution and F. hepatica absence/presence ratio within each cyst type, small cysts showed the highest difference in ratio. Conclusions To the best of our knowledge, this is the first report indicating that F. hepatica co-infection in cattle could be affecting the instate of hydatid cysts in the liver, displacing toward lung localization, suggesting an antagonistic relationship.