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1.
Int J Parasitol ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38609075

RESUMO

Parasitic salmon lice (Lepeoptheirus salmonis) are a constraint to the sustainable growth of salmonids in open net pens, and this issue has caused production to level off in recent years in the most aquaculture-intensive areas of Norway. The maximum allowed biomass at a regional level is regulated by using the so-called "traffic light" system, where salmon louse-induced mortality of migrating wild salmon post-smolts is evaluated against set targets. As a case study, we have investigated how a specific aquaculture-intensive area can reduce its louse levels sufficiently to achieve a low impact on wild salmon. Analyses of the output from a virtual post-smolt model that uses data on the reported number of salmon lice in fish farms as key input data and estimates the salmon louse-induced mortality of wild out-migrating Atlantic salmon post-smolts, suggested that female louse abundance on the local farms must be halved in spring to reach the goal implied by the traffic light system. The outcome of a modelling scenario simulating a proposed new plan for coordinated production and fallowing proved beneficial, with an overall reduction in louse infestations and treatment efforts. The interannual variability in louse abundance in spring, however, increased for this scenario, implying unacceptably high louse abundance when many farms were in their second production year. We then combined the scenario with coordinated production with other louse control measures. Only measures that reduced the density of farmed salmonids in open cages in the study area resulted in reductions in salmon louse infestations to acceptable levels. This could be achieved either by stocking with larger fish to reduce exposure time or by reducing fish numbers, e.g. by producing in closed units.

2.
Ecol Appl ; 34(3): e2956, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38426805

RESUMO

Gastrointestinal helminth parasites undergo part of their life cycle outside their host, such that developmental stages interact with the soil and dung fauna. These interactions are capable of affecting parasite transmission on pastures yet are generally ignored in current models, empirical studies and practical management. Dominant methods of parasite control, which rely on anthelmintic medications for livestock, are becoming increasingly ineffective due to the emergence of drug-resistant parasite populations. Furthermore, consumer and regulatory pressure on decreased chemical use in agriculture and the consequential disruption of biological processes in the dung through nontarget effects exacerbates issues with anthelmintic reliance. This presents a need for the application and enhancement of nature-based solutions and biocontrol methods. However, successfully harnessing these options relies on advanced understanding of the ecological system and interacting effects among biotic factors and with immature parasite stages. Here, we develop a framework linking three key groups of dung and soil fauna-fungi, earthworms, and dung beetles-with each other and developmental stages of helminths parasitic in farmed cattle, sheep, and goats in temperate grazing systems. We populate this framework from existing published studies and highlight the interplay between faunal groups and documented ecological outcomes. Of 1756 papers addressing abiotic drivers of populations of these organisms and helminth parasites, only 112 considered interactions between taxa and 36 presented data on interactions between more than two taxonomic groups. Results suggest that fungi reduce parasite abundance and earthworms may enhance fungal communities, while competition between dung taxa may reduce their individual effect on parasite transmission. Dung beetles were found to impact fungal populations and parasite transmission variably, possibly tied to the prevailing climate within a specific ecological context. By exploring combinations of biotic factors, we consider how interactions between species may be fundamental to the ecological consequences of biocontrol strategies and nontarget impacts of anthelmintics on dung and soil fauna and how pasture management alterations to promote invertebrates might help limit parasite transmission. With further development and parameterization the framework could be applied quantitatively to guide, prioritize, and interpret hypothesis-driven experiments and integrate biotic factors into established models of parasite transmission dynamics.


Assuntos
Anti-Helmínticos , Besouros , Parasitos , Animais , Bovinos , Ovinos , Solo/química , Fezes , Ruminantes
3.
Prev Vet Med ; 224: 106134, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38325114

RESUMO

The effective control of ectoparasitic salmon lice, Lepeophtheirus salmonis, in fish farms is challenged by the salmon lice having developed resistance towards several antiparasitic drugs and by the effectiveness of non-medicinal treatments being limited by considerations of fish welfare. When new antiparasitics are introduced to the market, these should be used sparingly to slow resistance development. Using a population model for salmon lice parameterised for salmonid fish farms in Norway, we quantified how reduced treatment effectiveness influences treatment frequency and lice abundance. Furthermore, we investigated when in the production cycle a highly effective lice treatment leads to the largest reduction in the total number of treatments, mean lice abundance and lice larvae production. Results showed that reductions in treatment effectiveness to lower than 50% led to the steepest increases in treatment frequency and mean lice abundance, as well as to increased risk that lice abundance increased beyond control. The timing of the most effective treatment had only moderate effects on the total treatment need and the mean number of adult female lice through the production cycle, but large effect on the production of lice larvae in spring. These findings imply that farmers can optimise the timing of the most effective treatment to reduce the release of lice larvae in the period of year when wild salmonids are in coastal waters, without compromising total treatment need or mean lice levels.


Assuntos
Copépodes , Doenças dos Peixes , Salmo salar , Salmonidae , Animais , Feminino , Pesqueiros , Antiparasitários/uso terapêutico , Larva , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/prevenção & controle , Doenças dos Peixes/epidemiologia , Salmão/parasitologia , Aquicultura/métodos
4.
J Photochem Photobiol B ; 251: 112847, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38241947

RESUMO

The bovine tick Rhipicephalus microplus, a primary ectoparasite of veterinary concern, contributes significantly to disease transmission and reduced cattle productivity, resulting in substantial economic losses. The overuse of chemical acaricides has led to the emergence of resistant strains, posing a considerable challenge to veterinary medicine. Consequently, the development of alternative parasite control methods is essential to ensure livestock quality and enhance food safety worldwide. Our study introduces an innovative approach to photodynamic inactivation (PDI) of the bovine tick, harnessing natural daylight for a potential field application. Reproductive parameters (female and egg mass, egg production index, and larval hatch) were evaluated in engorged female ticks under photodynamic action using the hematoporphyrin (HP) and tetra-cationic porphyrins free-base meso-tetra-ruthenated (4-pyridyl) (RuTPyP) and its zinc(II) complex (ZnRuTPyP) as photosensitizers (PS). The results showed that there was no significant difference between the groups treated with tetra­ruthenium porphyrins and the control group. However, HP exhibits a control percentage of 97.9% at a concentration of 2.5 µmol.L-1, aligning with the expected control rates achieved by conventional chemical acaricides. Photophysical and physicochemical parameters such as the number of singlet oxygen produced and lipophilicity were discussed for each PS and related to tick control percentages. Furthermore, the interaction between HP and chitin, an important macromolecule presents in the tick's cuticle, considered as the primary target tick structure during PDI was observed by the absorption and fluorescence emission spectroscopic techniques. Therefore, the results presented here extend the potential for controlling R. microplus through photodynamic inactivation while utilizing sunlight as a source of natural irradiation.


Assuntos
Acaricidas , Porfirinas , Rhipicephalus , Animais , Feminino , Bovinos , Acaricidas/farmacologia , Rhipicephalus/fisiologia , Porfirinas/farmacologia , Reprodução
5.
J Insect Sci ; 23(6)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38055946

RESUMO

The ectoparasitic mite, Varroa destructor (Anderson and Trueman), is the leading cause of western honey bee colony, Apis mellifera (L.), mortality in the United States. Due to mounting evidence of resistance to certain approved miticides, beekeepers are struggling to keep their colonies alive. To date, there are varied but limited approved options for V. destructor control. Vaporized oxalic acid (OA) has proven to be an effective treatment against the dispersal phase of V. destructor but has its limitations since the vapor cannot penetrate the protective wax cap of honey bee pupal cells where V. destructor reproduces. In the Southeastern United States, honey bee colonies often maintain brood throughout the year, limiting the usefulness of OA. Prior studies have shown that even repeated applications of OA while brood is present are ineffective at decreasing mite populations. In the summer of 2021, we studied whether incorporating a forced brood break while vaporizing with OA would be an effective treatment against V. destructor. Ninety experimental colonies were divided into 2 blocks, one with a brood break and the other with no brood break. Within the blocks, each colony was randomly assigned 1 of 3 treatments: no OA, 2 g OA, or 3 g OA. The combination of vaporizing with OA and a forced brood break increased mite mortality by 5× and reduced mite populations significantly. These results give beekeepers in mild climates an additional integrated pest management method for controlling V. destructor during the summer season.


Assuntos
Acaricidas , Criação de Abelhas , Abelhas , Ácido Oxálico , Varroidae , Animais , Abelhas/efeitos dos fármacos , Abelhas/parasitologia , Himenópteros/efeitos dos fármacos , Himenópteros/parasitologia , Ácido Oxálico/farmacologia , Estações do Ano , Varroidae/efeitos dos fármacos , Volatilização , Acaricidas/farmacologia , Criação de Abelhas/métodos , Cruzamento/métodos
6.
Vet Parasitol Reg Stud Reports ; 46: 100938, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37935539

RESUMO

The aim of this study was to investigate the occurrence of benzimidazole-resistant Haemonchus contortus in Norwegian sheep flocks. Screening was based on detection of one of the resistance-conferring mutations in the ß tubulin isotype 1 gene (F200Y, TAC) in larvae (L3) cultivated from H. contortus eggs from naturally infected sheep. Faecal samples were collected in 2021/2022 from flocks in the northern (n = 34), central (n = 7), eastern (n = 40), southern (n = 1), and western (n = 87) areas of Norway. In total, samples were taken from 169 flocks (spring-ewes samples: 167, autumn-lambs samples: 134). Individual faecal samples were collected from 10 randomly selected ewes (spring) and 10 randomly selected lambs (autumn) in each flock. Faecal samples collected from each flock on each occasion were pooled (lamb and ewe samples pooled separately) and cultured for L3 development. After harvest of larvae (Baermann method), DNA was extracted and then analysed using droplet digital PCR with primer/probe sets targeting the BZ-associated F200Y (TAC) mutation. Haemonchus was found in 60% (80/134) of samples from lambs, and in 63% (106/167) from ewes. Among these, the F200Y mutation was detected in 73% (58/80) of larval samples from lambs and 69% (73/106) of larval samples from ewes, respectively. Although regional differences were evident, the mutation was detected in all areas indicating a widespread distribution and a strong potential for an increasing problem with treatment-resistant haemonchosis in Norwegian sheep flocks.


Assuntos
Anti-Helmínticos , Haemonchus , Animais , Ovinos , Feminino , Haemonchus/genética , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Benzimidazóis/farmacologia , Reação em Cadeia da Polimerase/veterinária , Mutação
7.
Animals (Basel) ; 13(17)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37685005

RESUMO

In Sweden, routine deworming has been used for several decades; however, to slow down the development of anthelmintic resistance, selective treatment is currently recommended. As part of a monitoring programme, equestrian premises submitted faecal samples to the National Veterinary Institute (SVA) twice per year between 2008 and 2017. Analyses for strongyles (small and large), tapeworms and ascarids, followed by premise-specific advice regarding deworming and parasite control strategies, were provided. In total, 43,330 faecal samples, collected from 26,625 horses on 935 premises in springtime (March to June), were analysed by quantitative or semi-quantitative flotation. Moreover, Strongylus vulgaris was detected by larval culture or PCR. Between 4 and 11% of individual horses tested positive for S. vulgaris and 3-10% were shedding tapeworm eggs. There were recurrent high and low egg shedders; 75% of horses with S. vulgaris appeared to have been recently introduced into the herd; the proportion of S. vulgaris-positive premises increased when individual samples rather than pooled samples were used. Based on the results of S. vulgaris diagnostics and strongyle egg-shedding level, 59% of the horses did not need to be dewormed.

8.
One Health ; 17: 100587, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37415719

RESUMO

Many species of canine gastrointestinal (GI) parasites are known to be zoonotic meaning that dog owners' management and practices are key to preventing exposure of humans and dogs as well as contamination of the environment. As Australia has one of the highest rates of pet ownership in the world, we administered an online questionnaire to dog owners across the nation to assess their perceptions, practices, and behaviours towards canine GI parasites. Descriptive analysis was performed to summarise perceptions and management practices. Factors associated with the suitability of parasiticide treatments applied were investigated using uni- and multivariable ordinal regression. Just over a half of dog owners considered parasites as very or extremely important for their dog's health (59%) and less than a half as very or extremely important for human health (46%). Although the majority of dog owners stated that they deworm their dogs (90%), only the 28% followed best practice guidelines, i.e. administered a monthly prophylactic treatment all-year round. A large proportion of respondent dog owners administered prophylactic treatment at an inappropriate frequency (48%) or did not treat for canine GI parasites at all (24%). Attending vet visits at least once a year or once every six months and having a very comfortable or prosperous financial position were significantly associated with following best deworming prophylaxis guidelines. This study demonstrates that a proportion of dog owners in Australia is not complying with best practice regarding the control of canine GI parasites and is potentially exposing themselves and their dogs to the risk of infections. Veterinarians are called to implement dog owner's education, raise their awareness on the threats canine parasitic diseases pose to both dogs and humans and finally, encourage them to follow a monthly prophylactic treatment for canine GI parasites all year round.

9.
Proc Natl Acad Sci U S A ; 120(25): e2220922120, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37307477

RESUMO

Honey bees (Apis mellifera) are critical agricultural pollinators as well as model organisms for research on development, behavior, memory, and learning. The parasite Nosema ceranae, a common cause of honey bee colony collapse, has developed resistance to small-molecule therapeutics. An alternative long-term strategy to combat Nosema infection is therefore urgently needed, with synthetic biology offering a potential solution. Honey bees harbor specialized bacterial gut symbionts that are transmitted within hives. Previously, these have been engineered to inhibit ectoparasitic mites by expressing double-stranded RNA (dsRNA) targeting essential mite genes, via activation of the mite RNA interference (RNAi) pathway. In this study, we engineered a honey bee gut symbiont to express dsRNA targeting essential genes of N. ceranae via the parasite's own RNAi machinery. The engineered symbiont sharply reduced Nosema proliferation and improved bee survival following the parasite challenge. This protection was observed in both newly emerged and older forager bees. Furthermore, engineered symbionts were transmitted among cohoused bees, suggesting that introducing engineered symbionts to hives could result in colony-level protection.


Assuntos
Mel , Parasitos , Urticária , Abelhas , Animais , Agricultura , Genes Essenciais , RNA de Cadeia Dupla
10.
Parasitology ; 150(12): 1105-1118, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37039466

RESUMO

Helminth infections are ubiquitous in grazing ruminants and cause significant costs due to production losses. Moreover, anthelmintic resistance (AR) in parasites is now widespread throughout Europe and poses a major threat to the sustainability of modern ruminant livestock farming. Epidemiological data on the prevalence and distribution of gastrointestinal nematodes, cestodes and liver- and rumen-flukes in Italian small ruminants are outdated and fragmentary. However, anthelmintics are commonly used to control these infections and often without prior diagnosis. Compared to other European countries, few reports of AR in small ruminants against levamisole, ivermectin and benzimidazoles have been published in Italy, but recent studies suggest that this phenomenon is spreading. Increased and integrated research efforts in developing innovative approaches to control helminth infections and AR are needed and must be tailored to the peculiarities of each context in order to be effectively implemented. This manuscript provides an overview on helminth prevalence and distribution, sustainable treatment strategies and integrated control approaches in small ruminants in Italy. The implementation of targeted treatments and targeted selective treatments is discussed based on different parameters, such as fecal egg count, degree of anaemia (FAMACHA© method), milk production and body condition score. In addition, several Italian studies have also investigated the implementation of alternative strategies such as the use of different natural bioactive compounds or genetic selection for resistance and resilience to helminth infections. These concrete solutions for helminth management in small ruminant farms in the country are reported and discussed, representing a valid example for other Mediterranean countries.


Assuntos
Anti-Helmínticos , Helmintos , Nematoides , Infecções por Nematoides , Animais , Resistência a Medicamentos , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Ruminantes/parasitologia , Helmintos/genética , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/prevenção & controle
11.
Pathogens ; 12(3)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36986322

RESUMO

The purpose of using nematophagous fungi as biological control agents of gastrointestinal nematodes of livestock is to reduce the build-up of infective larvae on pasture and thus avoid clinical and subclinical disease. As the interaction of fungus-larval stages takes place in the environment, it is crucial to know how useful the fungal agents are throughout the seasons in areas where livestock graze all year-round. This study was designed to determine the predatory ability of the nematophagous fungus Duddingtonia flagrans against gastrointestinal nematodes of cattle during four experiments set up in different seasons. In each experiment, faeces containing eggs of gastrointestinal nematodes were mixed with 11,000 chlamydospores/g and deposited on pasture plots. A comparison between fungal-added faeces and control faeces without fungus were made with regard to pasture infectivity, larval presence in faecal pats, faecal cultures, faecal pat weight, and temperature inside the faecal mass. In three of the four experiments, Duddingtonia flagrans significantly reduced the population of infective larvae in cultures (68 to 97%), on herbage (80 to 100%), and inside the faecal pats (70 to 95%). The study demonstrated the possibility of counting on a biological control tool throughout most of the year in cattle regions with extensive grazing seasons.

12.
Vet Parasitol ; 317: 109904, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36907136

RESUMO

In view of the rising threat of anthelmintic resistance in parasite populations and the planned change of classification of anthelmintics in Ireland for food animals to prescription-only medicines, there is a need for increased focus on parasite control strategies for horses. Effective parasite control programs (PCPs) are complex, necessitating the application of risk-assessment based on host immune status, infection pressure, type of parasite and seasonality to determine the requirement for anthelmintic administration and an understanding of parasite biology to employ effective, non- therapeutic, parasite control measures. The aim of this study was to explore horse breeders' attitudes and behaviours towards general parasite control practices and anthelmintic use on thoroughbred studs in Ireland using qualitative research methods, in order to help identify barriers to the implementation of sustainable equine PCPs supported by veterinary involvement. One-to-one, qualitative, semi-structured interviews were conducted with 16 breeders, using an interview topic guide that allowed for an open questioning style. The topic guide facilitated discussion around the following areas: (i) parasite control measures (general approach, (ii) veterinary involvement, (iii) use of anthelmintics, (iv) use of diagnostics, pasture management), (v) recording of anthelmintic use and (vi) anthelmintic resistance. Convenience, purposive (subjective selection) sampling was used to select a small group of participants that reflected the characteristics of current thoroughbred breeders in Ireland taking into account farm type, farm size, geographical location. The interviews were transcribed, and a method of inductive thematic analysis (a data driven identification and analysis of themes) was performed. Assessment of current behaviours by these participants found that PCPs were primarily based on the prophylactic use of anthelmintics without a strategic rationale. A key driver of behaviour regarding parasite prevention practices was localised routine, dictated by tradition, that gave breeders a sense of confidence and protection regarding parasite control. The perceptions of the benefits of parasitology diagnostics were varied and their application to control was poorly understood. Anthelmintic resistance was recognised as an industry threat but not an issue for individual farms. By using a qualitative approach, this study offers insights into the possible barriers to the adoption of sustainable PCPs on Irish thoroughbred farms and highlights the need for end-user involvement in the preparation of future guidelines.


Assuntos
Anti-Helmínticos , Doenças dos Cavalos , Parasitos , Animais , Cavalos , Inquéritos e Questionários , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/prevenção & controle , Doenças dos Cavalos/tratamento farmacológico , Irlanda/epidemiologia , Criação de Animais Domésticos/métodos , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/farmacologia , Controle de Doenças Transmissíveis , Pesquisa Qualitativa , Resistência a Medicamentos , Contagem de Ovos de Parasitas/veterinária
13.
Prev Vet Med ; 213: 105882, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36867925

RESUMO

Global companion animal population has been increasing as well as the number of dogs and cats being considered as a family member. However, it is unclear whether this close relationship could be associated with higher preventive healthcare in companion animals. Using data from 7,048 questionnaires of dogs and 3,271 of cats from the First National Study on Responsible Companion Animal Ownership, we estimated the proportion of preventive healthcare in companion animals of Chile. We also conducted a general linear mixed-effect regression model to identify socioeconomic factors and indicators of the emotional owners-companion animal bond that could influence owners' practices related to vaccination, parasite control, and veterinary visits. Based on the owner's answers, Chile has a satisfactory overall rates of parasite control (71%) and annual veterinary visits (65%) but a low vaccination coverage of both dogs (39%) and cats (25%). 'Purebred', 'live in urban areas', 'acquired by monetary compensation', and 'dog species' were associated with a higher probability of preventive healthcare in companion animals. Conversely, this probability was lower among senior animals compared to adults, males, and those owned by the Silent Generation or Baby Boomers (i.e., owners born before 1964). 'Sleeping inside', 'acquired for an emotional reason' (e.g., companionship), and 'considered a family member' were positively associated with at least one of assessed preventive measures. Our findings suggest that emotional owner-companion animal bonds could positively impact the frequency and quality of preventive healthcare in dogs and cats. However, owners who totally disagreed that a companion animal is a "family member" were also associated with a higher likelihood of vaccination uptake and veterinary visits for their animals. This highlights that owner's compliance with veterinary preventive healthcare is multifactorial. Chile has a high prevalence of infectious diseases circulating among dogs and cats and increasingly close contacts between owners and companion animals due to emotional bonds. Thus, our study calls for One Health approaches to reduce the risks of cross-species disease transmission. Specifically, increasing vaccination coverage of companion animals in Chile is the most urgent preventive measure needed, especially among cats, males, and older animals. Expand preventive healthcare among dogs and cats will promote public and animal health, including local wildlife that is susceptible to infectious diseases circulating in companion animals.


Assuntos
Doenças do Gato , Doenças do Cão , Masculino , Animais , Gatos , Cães , Animais de Estimação , Doenças do Gato/epidemiologia , Doenças do Gato/prevenção & controle , Doenças do Gato/parasitologia , Chile/epidemiologia , Apego ao Objeto , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Doenças do Cão/parasitologia , Atenção à Saúde , Fatores Socioeconômicos , Inquéritos e Questionários , Propriedade
14.
Parasitol Res ; 122(4): 1033-1035, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36781471

RESUMO

Theodor Hiepe (1929-2022) was an outstanding researcher, a world-renowned scientist, a dedicated teacher and a great mentor. During his scientific career, which spanned over 60 years, he made major contributions to many different fields of parasitology. With the passing of Dr. h.c. mult. Theodor Hiepe in September 2022 the scientific community suffered a great loss.

15.
Int J Parasitol ; 53(2): 119-127, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36657611

RESUMO

Haemonchus contortus is the most prevalent and important gastrointestinal nematode (GIN) in small ruminants. Since it reduces the packed cell volume (PCV), causing anemia, early diagnosis can be used for targeted selective treatment (TST) of sheep, reducing antiparasitic drug use and anthelmintic resistance. This study aimed to predict PCV values through near-infrared spectroscopy (NIRS) and to develop a classification and diagnosis model of H. contortus infection using PCV values, eggs per gram of feces (EPG) counts and mean daily weight gain (DWG). A total of 1728 spectra were collected from blood samples of 216 lambs with a portable NIR spectroscope. In parallel, other parameters indicative of infection were measured: PCV by hematocrit, FAffa MAlan CHArt (FAMACHA) scores, EPG and DWG. To evaluate the relationship between NIRS spectra and the evaluated parameters, principal component analysis (PCA) was used for an exploratory analysis, regression by the partial least squares method (PLS) for the prediction of PCV values via NIRS, and PCA linear discriminant analysis (PCA-LDA) as a classification model for diagnosis. The absorption peaks in the NIRS region associated with the excitation of overtones of nitrogen-hydrogen (N-H) functional groups of proteins had a strong impact on the principal components (PCs), indicating that blood proteins, especially hemoglobin, can be estimated by the NIRS technique. The model for predicting PCV by PLS presented a standard error of prediction of 2.53, root-mean-square error of 2.48, and coefficient of determination of 0.84, indicating good correlation between the PCV values predicted by the model and the PCV obtained by hematocrit. The PCA-LDA model presented 93.33% sensitivity and 82.18% accuracy, both higher than those of the FAMACHA method, as was expected for resilient Morada Nova lambs. The multivariate models associated with the NIRS technique reported here can be used in the future as a quick and versatile tool for H. contortus infection diagnosis and TST application in lambs.


Assuntos
Anemia , Hemoncose , Haemonchus , Nematoides , Doenças dos Ovinos , Ovinos , Animais , Espectroscopia de Luz Próxima ao Infravermelho , Hematócrito/veterinária , Anemia/diagnóstico , Anemia/parasitologia , Anemia/veterinária , Aumento de Peso , Fezes/parasitologia , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Hemoncose/diagnóstico , Hemoncose/tratamento farmacológico , Hemoncose/veterinária , Contagem de Ovos de Parasitas/veterinária
16.
Parasitol Res ; 121(11): 3063-3071, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36066742

RESUMO

Global change in the Anthropocene has modified the environment of almost any species on earth, be it through climate change, habitat modifications, pollution, human intervention in the form of mass drug administration (MDA), or vaccination. This can have far-reaching consequences on all organisational levels of life, including eco-physiological stress at the cell and organism level, individual fitness and behaviour, population viability, species interactions and biodiversity. Host-parasite interactions often require highly adapted strategies by the parasite to survive and reproduce within the host environment and ensure efficient transmission among hosts. Yet, our understanding of the system-level outcomes of the intricate interplay of within host survival and among host parasite spread is in its infancy. We shed light on how global change affects host-parasite interactions at different organisational levels and address challenges and opportunities to work towards better-informed management of parasite control. We argue that global change affects host-parasite interactions in wildlife inhabiting natural environments rather differently than in humans and invasive species that benefit from anthropogenic environments as habitat and more deliberate rather than erratic exposure to therapeutic drugs and other control efforts.


Assuntos
Animais Selvagens , Parasitos , Animais , Animais Selvagens/parasitologia , Biodiversidade , Ecossistema , Interações Hospedeiro-Parasita/fisiologia , Humanos , Parasitos/fisiologia
17.
Vet Parasitol Reg Stud Reports ; 34: 100774, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36041809

RESUMO

Parasites can pose a risk to companion animals and potentially their owners. Current parasiticide use is possibly impacting the environment, increasing adverse reaction and resistance risk. As such parasiticides should be dispensed by the veterinary team proportional to individual risk, including owners in their approach. A mixed-methods questionnaire was designed and distributed using snowball sampling to ascertain overall awareness, observance, and attitude towards utilising a risk assessment based approach to parasite prophylaxis by UK companion animal veterinarians. 85.7% of veterinarians surveyed reported that they were aware of risk assessment based parasite control whereas only 53.9% said they utilise it always or often. Significant correlations were found between more frequent risk assessment based parasite control utilisation and increased owner involvement (P = 0.0007) and prescription confidence (P = 0.0001). Most attitudes towards adopting risk assessment based parasite control were positive. There was significant association with positive attitude and greater utilisation frequency (P = 0.0010), as well as working in corporate practice (P = 0.0126). Awareness of risk assessment based parasite control has potential to increase responsible utilisation of parasiticides by veterinarians, and therefore mitigate risks associated. Most veterinarians would like to see the profession move towards risk assessment based control use, but institutional changes are required. Further research, and education is also needed.


Assuntos
Médicos Veterinários , Animais , Antiparasitários , Controle de Doenças Transmissíveis , Humanos , Percepção , Animais de Estimação , Medição de Risco , Reino Unido
18.
Life (Basel) ; 12(5)2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35629416

RESUMO

Protozoa, helminths and ectoparasites are the major groups of parasites distributed worldwide. Currently, these parasites are treated with chemotherapeutic antiprotozoal drugs, anti-helminthic and anti-ectoparasitic agents, but, with the passage of time, resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving to be a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nanomedicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types of parasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. They work in different ways, that include damaging the parasite membrane, DNA (Deoxyribonucleic acid) disruption, protein synthesis inhibition and free-radical formation. These agents are effective against intracellular parasites as well. Other nanoparticles, such as iron, nickel, zinc and platinum, have also shown good results in the treatment and control of parasitic infections. It is hoped that this research subject will become the future of modern drug development. This review summarizes the methods that are used to synthesize nanoparticles and their possible mechanisms of action against parasites.

19.
Sci Total Environ ; 834: 155299, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35439509

RESUMO

Green nanoparticles (GNPs), mainly green silver nanoparticles (Ag NPs), have been recommended as sustainable and eco-friendly technologies to control vectors and intermediate hosts. The aim of the current study is to carry out a historical and systematic literature review about the use of green plant-based Ag NPs (GP-Ag NPs) to control medically important mosquito, tick and gastropods. Data about the number of studies published per year, geographical distribution of studies (mailing address of the corresponding author), synthesis type (plant species, plant structure and extract types), physicochemical properties of GP-Ag NPs, experimental designs, developmental stages and the toxic effects on mosquitoes, ticks and gastropods were summarized and discussed. Revised data showed that GP-Ag NPs synthesis and toxicity in mosquitoes, ticks and snails depend on plant species, plant part, extract types, exposure condition and on the analyzed species. GP-Ag NPs induced mortality, tissue damage, biochemical and behavioral changes in mosquitoes and reduced their fecundity, oviposition, egg hatching and longevity. Ticks exposed to GP-Ag NPs presented increased mortality and reduced oviposition, while on snails, studies demonstrated mortality, oxidative stress, and DNA damage. Immune responses were also observed in snails after their exposure to GP-Ag NPs. GP-Ag NPs reduced the reproduction and population of several vectors and intermediate hosts. This finding confirms their potential to be used in gastropod control programs. Future studies about current gaps in knowledge are recommended.


Assuntos
Culicidae , Nanopartículas Metálicas , Carrapatos , Animais , Feminino , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Mosquitos Vetores , Extratos Vegetais/química , Plantas , Prata/química
20.
Front Cell Infect Microbiol ; 12: 871860, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35419299

RESUMO

The intestinal parasite Cryptosporidium is a significant cause of severe diarrhoeal disease that can have long term effects. Therapeutic options remain limited despite a significant impact on public health, partly due to various challenges in the field of Cryptosporidium research, including the availability of genomic and transcriptomic data from environmental and clinical isolates. In this review we explore how long read DNA and RNA sequencing technologies have begun to provide novel insights into the biology of the parasite. The increased deployment of these technologies will help researchers address key gaps in the understanding of Cryptosporidium biology, and ultimately drive translational research and better parasite control.


Assuntos
Criptosporidiose , Cryptosporidium , Criptosporidiose/parasitologia , Cryptosporidium/genética , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Saúde Pública
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