Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 143
Filtrar
1.
Vet Immunol Immunopathol ; 242: 110338, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34717126

RESUMO

Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease affecting horses across the Americas. Gaps in understanding the inflammatory immune response in EPM-affected horses create difficulties with diagnosis and treatment, subsequently negatively impacting the prognosis of affected horses. The purpose of the current study was to evaluate circulating levels of the inflammatory immune marker soluble CD14 (sCD14), in horses with EPM (n = 7) and determine if they differed from healthy neurologically normal horses (n = 6). Paired sera and cerebrospinal fluid (CSF) samples were analyzed for sCD14. Inclusion criteria for EPM horses consisted of the presence of neurologic signs consistent with EPM, Sarcocystis neurona surface antigens 2, 4/3 (SnSAG 2, 4/3) ELISA serum: CSF antibody ratio ≤ 100, and a postmortem diagnosis of EPM. Control horses were neurologically normal, healthy horses with SnSAG 2, 4/3 ELISA serum: CSF antibody ratios of > 100. Serum anti-Sarcocystis neurona antibodies indicate that healthy control horses were exposed to S. neurona but resistant to developing clinical EPM. EPM cases had significantly greater concentrations of sCD14 in CSF samples compared to control horses and increased serum sCD14 concentrations. A positive correlation between sCD14 serum and CSF concentrations was observed in EPM-affected horses but not healthy horses. Soluble CD14 is an inflammatory marker, and the study results suggest it is elevated in EPM patients. When performed in conjunction with clinical evaluation and standard antibody testing, there may be potential for sCD14 to be utilized as a correlate for EPM.


Assuntos
Encefalomielite , Doenças dos Cavalos , Receptores de Lipopolissacarídeos/análise , Animais , Líquido Cefalorraquidiano , Encefalomielite/veterinária , Cavalos , Receptores de Lipopolissacarídeos/sangue
2.
Malar J ; 20(1): 349, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433465

RESUMO

BACKGROUND: Malaria still constitutes a major public health menace, especially in tropical and subtropical countries. Close to half a million people mainly children in Africa, die every year from the disease. With the rising resistance to frontline drugs (artemisinin-based combinations), there is a need to accelerate the discovery and development of newer anti-malarial drugs. A systematic review was conducted to identify the African medicinal plants with significant antiplasmodial and/or anti-malarial activity, toxicity, as wells as assessing the variation in their activity between study designs (in vitro and in vivo). METHODS: Key health-related databases including Google Scholar, PubMed, PubMed Central, and Science Direct were searched for relevant literature on the antiplasmodial and anti-malarial activities of African medicinal plants. RESULTS: In total, 200 research articles were identified, a majority of which were studies conducted in Nigeria. The selected research articles constituted 722 independent experiments evaluating 502 plant species. Of the 722 studies, 81.9%, 12.4%, and 5.5% were in vitro, in vivo, and combined in vitro and in vivo, respectively. The most frequently investigated plant species were Azadirachta indica, Zanthoxylum chalybeum, Picrilima nitida, and Nauclea latifolia meanwhile Fabaceae, Euphorbiaceae, Annonaceae, Rubiaceae, Rutaceae, Meliaceae, and Lamiaceae were the most frequently investigated plant families. Overall, 248 (34.3%), 241 (33.4%), and 233 (32.3%) of the studies reported very good, good, and moderate activity, respectively. Alchornea cordifolia, Flueggea virosa, Cryptolepis sanguinolenta, Zanthoxylum chalybeum, and Maytenus senegalensis gave consistently very good activity across the different studies. In all, only 31 (4.3%) of studies involved pure compounds and these had significantly (p = 0.044) higher antiplasmodial activity relative to crude extracts. Out of the 198 plant species tested for toxicity, 52 (26.3%) demonstrated some degree of toxicity, with toxicity most frequently reported with Azadirachta indica and Vernonia amygdalina. These species were equally the most frequently inactive plants reported. The leaves were the most frequently reported toxic part of plants used. Furthermore, toxicity was observed to decrease with increasing antiplasmodial activity. CONCLUSIONS: Although there are many indigenous plants with considerable antiplasmodial and anti-malarial activity, the progress in the development of new anti-malarial drugs from African medicinal plants is still slothful, with only one clinical trial with Cochlospermum planchonii (Bixaceae) conducted to date. There is, therefore, the need to scale up anti-malarial drug discovery in the African region.


Assuntos
Antimaláricos , Extratos Vegetais , Plantas Medicinais/química , Plasmodium/efeitos dos fármacos , África , Animais , Antimaláricos/farmacologia , Antimaláricos/toxicidade , Humanos , Malária/tratamento farmacológico , Medicinas Tradicionais Africanas/estatística & dados numéricos , Camundongos , Fitoterapia/estatística & dados numéricos , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade
3.
J Parasitol ; 107(4): 562-565, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34283238

RESUMO

We are interested in the disease ecology of Sarcocystis species that infect birds of prey as definitive and intermediate hosts. The present study was done to test our hypothesis that a laboratory model can be developed for sarcocystis infection in mammals using gamma interferon gene knockout (KO) mice as a source of Sarcocystis strixi bradyzoites and mammalian cell cultures as a source of sporulated S. strixi oocysts. Sporocysts of S. strixi from a naturally infected barred owl (Strix varia) were fed to KO mice to produce sarcocysts, and the enclosed bradyzoites were obtained by acid-pepsin digestion of abdominal and thigh muscles. Bradyzoites, metrocytes, and an unusual spherical stage were seen in digest before the inoculation of host cells. The spherical stages stained dark with Giemsa stain, but no nucleus was observed, and they were seen free and associated with the concave portion of some bradyzoites. Examination of infected cell cultures demonstrated that macrogamonts and microgamonts were present at 24 hr post-inoculation. Since sporulated oocysts were not observed, we had to reject our current hypothesis.


Assuntos
Doenças das Aves/parasitologia , Células Cultivadas/parasitologia , Aves Predatórias/parasitologia , Sarcocystis/fisiologia , Sarcocistose/veterinária , Animais , Camundongos , Camundongos Knockout , Sarcocystis/crescimento & desenvolvimento , Sarcocistose/parasitologia
4.
Vet Clin North Am Food Anim Pract ; 36(1): 205-222, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029185

RESUMO

Neospora caninum, Toxoplasma gondii, and Sarcocystis spp. are related Apicomplexan parasites that have 2 hosts in their life cycles. The definitive hosts excrete unsporulated (Neospora caninum, T gondii) or sporulated (Sarcocystis spp.) oocysts in their feces after ingesting tissue cysts from the tissues of ruminant intermediate hosts. These coccidians can cause abortion and neonatal mortality in ruminants. T gondii and Sarcocystis hominis (from cattle) are zoonotic. This article reviews information on the etiology, life cycle, diagnosis, control and prevention of these parasites and the diseases they cause in ruminants.


Assuntos
Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Doenças das Cabras/parasitologia , Sarcocistose/veterinária , Doenças dos Ovinos/parasitologia , Animais , Bovinos , Cabras , Neospora/isolamento & purificação , Ruminantes/parasitologia , Ovinos , Toxoplasma/isolamento & purificação , Toxoplasmose Animal
5.
J Vet Intern Med ; 33(3): 1272-1277, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30982235

RESUMO

BACKGROUND: An evaluation of currently available in-clinic diagnostic tests for Giardia duodenalis infection of dogs and cats has not been performed. In addition, there is discordance among published diagnostic comparisons. The absence of a true gold standard for detecting Giardia duodenalis also complicates diagnostic evaluations. OBJECTIVES: To evaluate diagnostic tests commercially available in the United States for detecting Giardia duodenalis in dogs and cats, in comparison to a widely used reference test, the direct immunofluorescent assay (IFA), and also to compare the results of 2 methods of analysis: comparison of diagnostic tests to a reference test (IFA) and Bayesian analysis. ANIMALS: Fecal samples from a convenience sample of 388 cats and dogs located in Colorado, Oklahoma, and Virginia. METHODS: Fecal samples were tested for Giardia duodenalis by zinc sulfate centrifugal fecal flotation and 4 different commercial diagnostic immunoassays. Results were analyzed via Bayesian analysis and by comparison to the IFA as the reference test. RESULTS: Sensitivity and specificity by comparison to IFA was ≥82% and ≥90%, respectively, for all diagnostic tests in dogs and cats. When analyzed via Bayesian analysis, sensitivity and specificity were ≥83% and ≥95%, respectively. When ZnSO4 centrifugal fecal flotation results were combined with immunoassay results, there was no longer a significant difference between the sensitivities of the commercial in-clinic immunoassays. CONCLUSION AND CLINICAL RELEVANCE: The Bayesian analysis validates using IFA as the reference test. Differences in commercial in-clinic immunoassay sensitivities can be mitigated when the results are combined with ZnSO4 centrifugal fecal flotation results.


Assuntos
Doenças do Gato/parasitologia , Doenças do Cão/parasitologia , Fezes/parasitologia , Técnica Direta de Fluorescência para Anticorpo/veterinária , Giardíase/veterinária , Animais , Doenças do Gato/diagnóstico , Gatos , Centrifugação/métodos , Centrifugação/veterinária , Doenças do Cão/diagnóstico , Cães , Técnica Direta de Fluorescência para Anticorpo/métodos , Giardíase/diagnóstico , Sensibilidade e Especificidade , Estados Unidos
6.
J Parasitol ; 105(2): 371-378, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31033388

RESUMO

Sarcocystis neurona is a ubiquitous parasite in the eastern United States, which is the principal causative agent in the neurologic disorder equine protozoal myeloencephalitis (EPM). While much is known about this protozoa's life cycle in its natural host, the opossum (Didelphis virginiana), little is known of how it acts in the aberrant equine host, which displays a high incidence of exposure with a relatively low rate of morbidity. For this study, we employed the popular interferon gamma knockout mouse model to determine the potential for recrudescence of S. neurona infection after treatment with the anticoccidial drug diclazuril. Mice were infected with S. neurona merozoites, and 7-days post-infection (DPI) they were treated with diclazuril for 30 or 60 days or not treated at all. All infected non-treated mice developed neurologic signs consistent with S. neurona infection within 30 DPI. All diclazuril-treated infected mice remained clinically normal while on treatment but developed neurologic signs within 60 days of treatment cessation. Histological examination of cerebella from all infected mice demonstrated characteristic lesions of S. neurona infection, regardless of treatment status. Cerebellar samples collected from infected treated mice, displaying neurologic signs, produced viable S. neurona in culture. However, cerebellar samples collected from infected and neurologically normal mice at the end of a 30-day treatment period did not produce viable S. neurona in culture. Analysis of the humoral immune response in infected mice showed that during treatment IgM antibody production decreased, suggesting the organism was sequestered from immune surveillance. The cessation of treatment and subsequent development of neurologic disease resulted in increased IgM antibody production, suggesting recognition by the immune system at that time. Based on the study results the authors propose that diclazuril was able to inhibit the replication and migration of S. neurona but not fully eliminate the parasite, suggesting recrudescence of infection after treatment is possible.


Assuntos
Coccidiostáticos/uso terapêutico , Encefalomielite/parasitologia , Nitrilas/uso terapêutico , Sarcocystis/patogenicidade , Sarcocistose/parasitologia , Triazinas/uso terapêutico , Animais , Encéfalo/parasitologia , Cerebelo/parasitologia , Cerebelo/patologia , Chlorocebus aethiops , Coccidiostáticos/farmacologia , Encefalomielite/tratamento farmacológico , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Imunoglobulinas/sangue , Imuno-Histoquímica , Interferon gama/genética , Masculino , Camundongos , Camundongos Knockout , Nitrilas/farmacologia , Gambás/parasitologia , Recidiva , Sarcocystis/efeitos dos fármacos , Sarcocistose/tratamento farmacológico , Triazinas/farmacologia , Células Vero
7.
Vet Parasitol Reg Stud Reports ; 15: 100257, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30929934

RESUMO

Giardia duodenalis is considered a species complex that is divided into 8 genetically distinct but morphologically identical assemblages (A-H). Assemblages C-H are generally host adapted, while A and B infect both people and animals and are considered potentially zoonotic. Furthermore, within assemblage A there are four subtypes (AI, AII, AIII, and AIV) of varying zoonotic potential; human isolates belong to AI and AII, while animal isolates belong to AI, AIII and AIV. Assemblages A, B, C, D, and F have all been reported from cats. The objective of this study was to determine the assemblage(s) of G. duodenalis present in cats from Virginia using multilocus genotyping and to assess if there were any differences among the assemblage(s) found in the populations of cats surveyed (free-roaming, shelter, owned) or their geographic location within Virginia. Samples that were positive for G. duodenalis cysts by microscopy using centrifugal flotation with ZnSO4 solution and/or direct immunofluorescence assay were genotyped using PCR and sequencing targeting fragments of the SSU rRNA, gdh, bg, and tpi genes. In total, 54 cyst-positive samples were analyzed by PCR and sequencing: 43 produced amplicons, and 37 samples had interpretable sequence data at one or more loci. Assemblage F was detected in 21/37 samples, AI was detected in 12/37 samples, and in 4/37 samples both assemblages F and AI were detected. The potentially zoonotic assemblage AI was detected in cats from two widely separated animal shelters and from one free-roaming cat. These genotyping data demonstrate that potentially zoonotic G. duodenalis assemblages are present in cats in Virginia.


Assuntos
Gatos/parasitologia , Giardia lamblia/genética , Giardíase/veterinária , Animais , DNA de Protozoário/genética , Técnicas de Genotipagem , Giardia lamblia/isolamento & purificação , Giardíase/diagnóstico , Tipagem de Sequências Multilocus , Filogenia , Reação em Cadeia da Polimerase , Virginia
8.
J Parasitol ; 105(2): 199-202, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30860942

RESUMO

Canine and feline heartworm disease caused by Dirofilaria immitis is a serious and sometimes fatal infection transmitted by mosquitos. Little is known about the prevalence or distribution of D. immitis infection in dogs and cats on the island of Hainan island/province or coastal cities of China. The present study examined the occurrence of D. immitis infections in dogs (n = 869) and cats (n = 51) in Hainan island/province and prevalence in dogs from 3 coastal cities (Shenzhen [n = 55], Shanghai [n = 69], and Hangzhou [n = 45]) in southern and eastern China. A commercial antigen detection (AD) test and 2 PCR methods (16S ribosomal RNA and Wolbachia surface protein [ WSP] genes) were used to determine the prevalence of D. immitis from animals >6 mo old with no previous history of D. immitis preventive treatment or heartworm infection. Gene sequencing was used to confirm positive PCR samples. The AD test was not used on cat samples. Using the AD test, the prevalence in dogs was 0.5% (4/869) in Hainan island/province, 0% (0/55) in Shenzhen, 1.5% (1/69) in Shanghai, and 0% (0/45) in Hangzhou. Prevalence by 16S rRNA gene PCR was 7.4% (64/869) of dogs from Hainan island/province, 0% (0/55) in dogs from Shenzhen, 1.5% (1/69) in dogs from Shanghai, and 0% (0/45) in dogs from Hangzhou. Prevalence by WSP gene PCR in dogs was 5.3% (46/869) in Hainan island/province, 0% (0/55) in Shenzhen, 1.5% (1/69) in Shanghai, and 0% (0/45) in Hangzhou. Prevalence in the 51 cats from Hainan island/province was 9.8% and 5.9% by 16S rRNA and WSP gene PCR, respectively. The present study demonstrates that canine heartworm exposure occurs in dogs and cats in Hainan island/province and that PCR methods detected a higher prevalence than did the AD method. The 16S rRNA gene PCR detected more positive samples than did the WSP gene PCR in both dogs and cats. The 3 coastal cities had very few dogs that had evidence of D. immitis exposure.


Assuntos
Doenças do Gato/epidemiologia , Dirofilariose/epidemiologia , Doenças do Cão/epidemiologia , Animais , Doenças do Gato/parasitologia , Gatos , China/epidemiologia , Doenças do Cão/parasitologia , Cães , Prevalência , População Urbana
9.
Vet Parasitol ; 266: 34-55, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30736946

RESUMO

Until 1970, coccidian parasites of dogs were considered to have a direct fecal-oral life cycle like Eimeria in poultry. They were thought to be non-host specific and infect both dogs and cats. Studies conducted in the 1970s revealed that dog coccidia were host-specific and had transport or paratenic hosts that were infected with an encysted stage containing a single organism, the monozoic tissue cyst. There are still considerable confusion and uncertainties concerning the life cycles and pathogenicity of coccidian parasites of dogs. The present paper reviews the history, taxonomy, life cycles, pathogenicity, epidemiology, diagnosis, and treatment of conventional coccidian parasites previously called Isospora spp., currently designated Cystoisospora spp. that infect canines.


Assuntos
Coccidiose/veterinária , Doenças do Cão/parasitologia , Cães/parasitologia , Animais , Coccidiose/diagnóstico , Coccidiose/tratamento farmacológico , Coccidiose/história , Doenças do Cão/diagnóstico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/história , Fezes/parasitologia , História do Século XX , História do Século XXI , Isospora/classificação , Isospora/patogenicidade , Estágios do Ciclo de Vida
10.
J Parasitol ; 105(1): 143-145, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807718

RESUMO

Here, we report confirmation of sarcocysts of Sarcocystis jamaicensis in an experimental intermediate host, IFN-γ gene knockout (KO) mice orally inoculated sporocysts from its natural definitive host, a red-tailed hawk ( Buteo jamaicensis) (RTH). A RTH submitted to the Carolina Raptor Center, Huntersville, North Carolina, was euthanized because it could not be rehabilitated and released. Fully sporulated sporocysts from intestinal scrapings of the RTH were orally fed to 2 laboratory-reared outbred Swiss Webster mice (SW; Mus musculus) and to 2 KO mice. The sporocysts were infective for KO mice but not to SW mice. Both SW mice remained asymptomatic, and neither schizonts nor sarcocysts were found in their tissues when euthanized on day 54 post-inoculation (PI). The KO mice developed neurological signs and were necropsied 38-54 days PI. Schizonts/merozoites were found in both KO mice euthanized and they were confined to the brain. The predominant lesion was meningoencephalitis. Microscopic sarcocysts were found in muscles of both KO mice. When viewed with light microscopy, the sarcocyst wall appeared thin (<1 µm thick) and smooth. Ultrastructural details of sarcocysts are described.


Assuntos
Doenças das Aves/parasitologia , Falcões/parasitologia , Interferon gama/genética , Sarcocystis/fisiologia , Sarcocistose/veterinária , Animais , Doenças das Aves/genética , Doenças das Aves/patologia , Encéfalo/parasitologia , Chlorocebus aethiops , Feminino , Meningoencefalite/parasitologia , Meningoencefalite/patologia , Meningoencefalite/veterinária , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão/veterinária , North Carolina , Sarcocystis/isolamento & purificação , Sarcocystis/ultraestrutura , Sarcocistose/genética , Sarcocistose/parasitologia , Sarcocistose/patologia , Células Vero
11.
J Parasitol ; 105(1): 11-16, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807729

RESUMO

The life cycle of Sarcocystis species is heteroxenous (2-host), with carnivores being the definitive host and herbivores serving as intermediate hosts in predator-prey relationships. Raptors (eagles, hawks, falcons, and owls) are apex predators and are not consumed routinely by other carnivores, making the occurrence of sarcocysts in their muscles unusual. Recent reports of sarcocysts in eagles and owls with Sarcocystis encephalitis suggests that this condition may be becoming more frequent, and Sarcocystis falcatula has been implicated as the agent of encephalitis in golden ( Aquila chrysaetos) and bald eagles ( Haliaeetus leucocephalus) as well as great horned owls ( Bubo virginianus). The present study was done to determine the prevalence of sarcocysts of Sarcocystis species in the muscles of raptors from the southeastern United States. Pectoral and heart muscle from 204 raptor patients from the Carolina Raptor Center, Huntersville, North Carolina were tested for the presence of Sarcocystis species using histology. Only a few sarcocysts were seen in sections of pectoral muscle from 39 of 204 raptors (19.1%) and heart muscle from 9 that also had sarcocysts in their pectoral muscle. Two structural types of sarcocysts, thin-walled (1 µm; 62%) or thick-walled (>2 µm, 38%), were seen. Statistical analysis of raptor age and gender was done by Fisher's exact test on samples from raptors with 20 or more samples per group. The prevalence of sarcocysts by age (2 yr or more) was significant for red-shouldered hawks ( Buteo lineatus) ( P = 0.022) and Cooper's hawks ( Accipiter cooperii) ( P = 0.028). Sarcocyst prevalence in male raptors from these groups evaluated statistically were always less than in females. Prevalence in female red-tailed hawks ( Buteo jamaicensis) (42.1%) was significantly greater than in males (6.7%) using Fisher's exact test ( P = 0.047). Examination of case histories from the 39 sarcocyst-positive raptors did not reveal an association with sarcocysts in raptor pectoral or heart muscle and in a diagnosis of encephalitis. Additional studies are needed to determine the epidemiology and relationships of Sarcocystis spp. that use raptors as intermediate hosts and the importance of Sarcocystis spp. in the overall wellbeing of raptors in their natural environments.


Assuntos
Doenças das Aves/parasitologia , Músculo Esquelético/parasitologia , Aves Predatórias/parasitologia , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Doenças das Aves/epidemiologia , Falconiformes/parasitologia , Feminino , Falcões/parasitologia , Masculino , North Carolina/epidemiologia , Prevalência , Centros de Reabilitação , Sarcocistose/epidemiologia , Sarcocistose/parasitologia , Fatores Sexuais , Sudeste dos Estados Unidos/epidemiologia , Estrigiformes/parasitologia
12.
Acta Trop ; 188: 240-243, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30219554

RESUMO

Equine hosts suffer from neurological disease, congenital infection, and reproductive problems associated with Neospora spp. infection. We conducted a cross sectional study using sera from 631 equids (324 horses, 218 donkeys and 89 mules) from the southern region of Punjab province, Pakistan to determine the prevalence of antibodies against Neospora spp. in this diverse group of equines. Fisk factors associated with seropositivity were evaluated statistically based on equine type, breed, age, husbandry, breeding methods, and reproductive history. Prevalence of antibodies to Neospora spp. was detected using a commercially available competitive ELISA kit. We detected IgG antibodies to Neospora spp. in 23.3% of the equids with prevalence by host being 16.0% in horses, 32.6% in donkeys and 26.9% in 89 mules. Statistically significant (P < 0.05) differences in prevalence were observed among these hosts. Prevalence ranged in breeds of horses from 3.7% in the Morna breed, 12.4% in breeding stock, 26.8% in draughting stock, to 31.4% in unknown breeds. No significant (P > 0.05) difference in prevalence was noted among age groups. Prevalence was significantly (P < 0.05) higher in female equines with a history of abortion than those with no history of abortion. This is the first report documenting Neospora spp. in equines from Pakistan and it provides evidence that Neospora spp. is associated with abortions in female equines in Pakistan.


Assuntos
Anticorpos Antiprotozoários/sangue , Coccidiose/veterinária , Equidae/parasitologia , Neospora/imunologia , Animais , Estudos Transversais , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Imunoglobulina G/sangue , Masculino , Paquistão/epidemiologia , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos
13.
Vet Parasitol ; 253: 102-119, 2018 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-29604993

RESUMO

This guideline is intended as an aid in the design, implementation and interpretation of studies for the assessment of drug efficacy against Eimeria in cattle and sheep, Cystoisospora in pigs and dogs, and Cryptosporidium in cattle. It deals with the most important aspects of how to conduct both experimental and field studies for dose determination, dose confirmation and assessment of field effectiveness. Also, guidance on the selection of animals, diagnostic techniques, statistical evaluation and methods for the preparation, maintenance and use of parasites is provided. The specific management conditions that may influence the course of natural infections and consequently determine treatment schemes are mentioned and suggestions for best practice in sampling and evaluation of data prior to conducting of efficacy studies are given. The guideline is also intended to assist investigators in carrying out specific studies, provide relevant information for registration authorities involved in the decision-making process, assist in the approval of anticoccidial drugs in the target species, and facilitate the world-wide adoption of standard procedures. Although currently not implemented, issues of drug resistance testing and alternative methods for drug testing are also discussed as future issues in drug testing against mammalian coccidia.


Assuntos
Coccídios/efeitos dos fármacos , Coccidiose/veterinária , Coccidiostáticos/uso terapêutico , Guias como Assunto , Animais , Bovinos , Coccidiose/tratamento farmacológico , Coccidiose/parasitologia , Cães , Avaliação de Medicamentos/veterinária , Ovinos , Suínos , Medicina Veterinária
14.
J Med Entomol ; 55(4): 1040-1042, 2018 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-29415246

RESUMO

Cutaneous leishmaniasis is a vector-borne infection caused by flagellated parasitic protozoans in the genus Leishmania. Promastigotes are the infective stage, which are transmitted by the bite of female sand flies of the genera Phlebotomus or Lutzomyia. Three clinical forms of Leishmania infection are recognized in humans, and they are caused by different Leishmania species. They are cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (ML), and visceral leishmaniasis (VL). Up to 2 million cases of leishmaniasis are reported annually worldwide. In Pakistan, CL is widely distributed in endemic areas. In the current study, a survey was conducted to investigate the occurrence of CL in an endemic area of the metropolitan city of Multan, Pakistan. The material for diagnosis of CL was obtained from 461 patients from 239 clinical laboratories and health care centers in Multan. Of these patients, 42.9% (198 of 461) having positive findings of amastigotes in Giemsa stained tissue impression smears. The distribution of CL skin lesions was highly variable. Most patients (76.2%) had a single lesion. Most CL lesions were found on a single hand (23.7%). The prevalence of two CL lesions per patient was 21.7%, while three or more positive CL lesions were observed in 2.0% of patients. The 198 CL-positive patients ranged in age 10-40 yr old, 101 were males, and 97 were females. Logistic regression analysis of leishmaniasis versus age and gender showed that both the age and gender had a significant (P < 0.05) effect on the occurrence of infection. Outbreaks of CL were reported in 14 of the 68 Union Councils of Multan.


Assuntos
Surtos de Doenças , Doenças Endêmicas/estatística & dados numéricos , Insetos Vetores/parasitologia , Leishmaniose Cutânea/epidemiologia , Psychodidae/parasitologia , Adolescente , Adulto , Animais , Criança , Cidades/epidemiologia , Feminino , Humanos , Leishmaniose Cutânea/parasitologia , Masculino , Doenças Negligenciadas/epidemiologia , Doenças Negligenciadas/parasitologia , Paquistão/epidemiologia , Adulto Jovem
15.
Front Vet Sci ; 5: 335, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30687725
16.
Zoonoses Public Health ; 65(6): 728-735, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-31348621

RESUMO

Felis catus, the domestic cat, is the definitive host for parasites that may result in adverse health outcomes in humans. Prevalence data of zoonotic parasites in feral cats, which are free-roaming domestic cats that are born and live in the wild, are limited. The objective of this study was to assess seroprevalence of Toxoplasma gondii antibodies and copro-prevalence of potentially zoonotic parasites in feral cats and to evaluate risk factors for seropositivity and faecal excretion of parasites. In this cross-sectional survey, 275 feral cats at Trap-Neuter-Release clinics in Central Virginia were tested for parasites via faecal flotation, direct immunofluorescence assay (faeces) and modified agglutination testing (serum). Toxoplasma gondii seroprevalence was 22.35% (95% CI: 17.47-27.86). Faecal prevalence of T. gondii-like oocysts was 1.04% (95% CI: 0.13-3.71), Toxocara cati 58.85% (95% CI: 51.54-65.89), Ancylostoma spp. 18.75% (95% CI: 13.49-25.00), Giardia duodenalis 5.73% (95% CI: 2.89-10.02) and Cryptosporidium spp. 3.33% (95% CI: 1.37-7.24). Female cats were more likely than males to excrete faecal Ancylostoma spp. eggs (OR 2.88; 95% CI 1.34-6.17). Adults were more likely than immature cats to be seropositive (OR 2.10; 95% CI: 1.11-3.97) and to excrete faecal Ancylostoma spp. eggs (OR 2.57; 95% CI: 1.10-5.99). However, immature cats were more likely than adults to excrete T. cati eggs (OR 6.79; 95% CI: 3.31-13.90) and to excrete one or more potentially zoonotic species (OR 4.67; 95% CI: 2.28-9.55) in faeces. Results of this study have implications for human and animal health and highlight the importance of collaboration between public health, medical and veterinary communities in preventive efforts.


Assuntos
Doenças do Gato/parasitologia , Doenças Parasitárias em Animais/parasitologia , Zoonoses , Animais , Doenças do Gato/epidemiologia , Gatos , Feminino , Humanos , Masculino , Propriedade , Doenças Parasitárias em Animais/epidemiologia , Fatores de Risco , Estudos Soroepidemiológicos , Virginia/epidemiologia
17.
J Parasitol ; 103(5): 598-601, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28590167

RESUMO

Ascaris suum is an important intestinal nematode causing economic losses in swine. Anthelminthic treatment is used to control A. suum infections and is part of normal production practices. Treatment with anthelminthic agents results in expulsion of adult worms from the intestinal tract and ends further contamination of the environment with eggs. The present study was conducted to determine the effects of drug treatment on the embryonation of A. suum eggs collected from worms obtained from pigs treated with 4 different commercially available anthelmintics. The effects of treatment with abamectin, doramectin, ivermectin, flubendazole, or no treatment on embryonation of A. suum eggs collected from female A. suum expelled in the feces was determined. The embryonation of eggs obtained from pigs treated with abamectin, doramectin, and ivermectin was not significantly (P > 0.05) different from eggs from non-treated control pigs. In contrast, the embryonation of A. suum eggs collected from worms from pigs treated with flubendazole demonstrated inhibited development, and most eggs remained in the 1-cell stage (85.5%) and only 6.3% of eggs developed larvae. In another experiment, we examined the direct effects of doramectin and flubendazole added to solutions of A. suum eggs collected from non-treated control pigs. Egg cultures were exposed to direct in vitro treatment with 0.04-parts per million (ppm) doramectin or 1.0-ppm flubendazole for 24 hr (highest concentrations [Cmax] of drugs in serum) and then embryonation and infectivity for mice was determined. Treatment of eggs in vitro did not significantly effect (P > 0.05) larval development or oral infectivity for mice. Our study demonstrates that flubendazole fed to pigs results in inhibited embryonation of A. suum eggs. However, direct treatment of A. suum eggs in culture for 24 hr with flubendazole did not inhibit embryonation or oral infectivity of in vitro treated eggs. Anthelmintic treatment of pigs in vivo with abamectin, doramectin, and ivermectin had no significant (P > 0.05) effect on embryonation of A. suum eggs, and 24 hr treatment with doramectin in vitro had no direct effects (P > 0.05) on embryonation or oral infectivity of A. suum eggs.


Assuntos
Anti-Helmínticos/farmacologia , Ascaríase/tratamento farmacológico , Ascaris suum/efeitos dos fármacos , Doenças dos Suínos/parasitologia , Administração Oral , Ração Animal , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Ascaríase/parasitologia , Fezes/parasitologia , Feminino , Injeções Subcutâneas , Ivermectina/administração & dosagem , Ivermectina/análogos & derivados , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Mebendazol/administração & dosagem , Mebendazol/análogos & derivados , Mebendazol/farmacologia , Mebendazol/uso terapêutico , Camundongos , Óvulo/efeitos dos fármacos , Contagem de Ovos de Parasitas/veterinária , Suínos
18.
Trop Anim Health Prod ; 49(5): 1081-1084, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28470581

RESUMO

Infection with the Apicomplexan parasite Neospora caninum occurs in domestic and wild animals worldwide. This parasite causes significant economic losses in the dairy industry worldwide. The current study was designed to assess the prevalence of N. caninum antibodies in the sera of camels (Camelus dromedarius) from Rakh Mahni, Bhakkar, Pakistan, to better understand the epidemiology of this important cause of bovine abortion in Pakistan. Eighty-one sera samples collected from apparently healthy camels (male = 19, female = 62) were tested for antibodies against N. caninum by using a commercially available competitive Enzyme Linked Immunosorbent assay diagnostic kit. Nine (11.1%) of 81 sera samples were found positive for antibodies to N. caninum. No significant (P > 0.05) difference in seroprevalence was observed between male and female camels or between different breeds. An increasing trend of seropositivity to N. caninum was seen with the age of animals indicating postnatal exposure to N. caninum infection. However, this increase in prevalence was not significant (P > 0.05). However, a significant (P < 0.05) difference in seroprevalence was noted among feeding style of animals, i.e., stall feeding, grazing, and mixed (grazing and stall feeding) feeding style. The prevalence was significantly (P < 0.05) higher in female animals 26.1% (6/23) with abortion history that of animals have had no such history 5.1% (2/39). Presence of antibodies to N. caninum in the sera of camels indicates that further studies are required to evaluate the importance of N. caninum as a cause of abortion or neonatal disease in these animals.


Assuntos
Aborto Animal/epidemiologia , Camelus , Coccidiose/veterinária , Neospora/isolamento & purificação , Aborto Animal/parasitologia , Animais , Anticorpos Antiprotozoários/sangue , Coccidiose/epidemiologia , Coccidiose/parasitologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Masculino , Paquistão/epidemiologia , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos
19.
J Parasitol ; 103(2): 183-186, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27874323

RESUMO

Toxocara canis is a common intestinal nematode of young dogs. Puppies contaminate the environment with large numbers of eggs that can embryonate and become infective in less than a month. Embryonated eggs are infectious for humans and other paratenic hosts. Most T. canis infections in humans are asymptomatic; however, migration of T. canis larvae in the eye and in the central nervous system can result in vision loss, blindness, and even death. The eggs of T. canis are highly resistant to harsh environmental conditions and routinely used chemical disinfectants. The objective of this study was to evaluate the effects of full-strength commercial bleach (5.25% sodium hypochlorite solution) treatment on development of T. canis eggs and to report our serendipitous finding that T. canis eggs in dog feces can float in passive fecal flotation tests using bleach. We also demonstrated that T. canis eggs could be identified using the McMaster's fecal eggs counting test using 100% bleach. Toxocara canis eggs collected from the feces of naturally infected 4-8 wk old puppies were treated with full-strength bleach (5.25% sodium hypochlorite solution) for 15 min, 30 min, 60 min, and 120 min; washed free of bleach smell by centrifugation; and resuspended in 0.1 N sulfuric acid solution to undergo larval development at room temperature for 18 days after exposure to bleach. Motile larvae were observed in T. canis eggs in all groups treated for 15-120 min and eggs continuously exposed to bleach for 18 days. Our results indicate that bleach may not be an appropriate disinfectant for dog kennels, cages, or laboratory utensils and work surfaces. Toxocara canis eggs are resistant to bleach treatment and continue to pose a risk for canine and human infections. Further study is needed to find the most appropriate methods for disinfection and removal of eggs to reduce the risk of transmission of this parasite.


Assuntos
Desinfetantes/farmacologia , Oxidantes/farmacologia , Hipoclorito de Sódio/farmacologia , Toxocara canis/crescimento & desenvolvimento , Animais , Desinfetantes/química , Cães , Fezes/parasitologia , Humanos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Oxidantes/química , Contagem de Ovos de Parasitas , Hipoclorito de Sódio/química , Gravidade Específica , Fatores de Tempo , Toxocara canis/efeitos dos fármacos
20.
Parasitol Int ; 66(2): 106-111, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28033565

RESUMO

Raptors serve as the definitive host for several Sarcocystis species. The complete life cycles of only a few of these Sarcocystis species that use birds of prey as definitive hosts have been described. In the present study, Sarcocystis species sporocysts were obtained from the intestine of a Cooper's hawk (Accipiter cooperii) and were used to infect cell cultures of African green monkey kidney cells to isolate a continuous culture and describe asexual stages of the parasite. Two clones of the parasite were obtained by limiting dilution. Asexual stages were used to obtain DNA for molecular classification and identification. PCR amplification and sequencing were done at three nuclear ribosomal DNA loci; 18S rRNA, 28S rRNA, and ITS-1, and the mitochondrial cytochrome c oxidase subunit 1 (cox1) locus. Examination of clonal isolates of the parasite indicated a single species related to S. columbae (termed Sarcocystis sp. ex Accipiter cooperii) was present in the Cooper's hawk. Our results document for the first time Sarcocystis sp. ex A. cooperii occurs naturally in an unknown intermediate host in North America and that Cooper's hawks (A. cooperii) are a natural definitive host.


Assuntos
Doenças das Aves/parasitologia , Falcões/parasitologia , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Linhagem Celular , Chlorocebus aethiops , Clonagem Molecular , Ciclo-Oxigenase 1/genética , DNA Ribossômico/genética , Microscopia Eletrônica de Transmissão , Oocistos/ultraestrutura , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico/genética , Reprodução Assexuada/fisiologia , Sarcocystis/classificação , Sarcocystis/crescimento & desenvolvimento , Sarcocistose/parasitologia , Esquizontes/crescimento & desenvolvimento , Esquizontes/ultraestrutura , Análise de Sequência de DNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA