Publications by authors named "Gerald C Coles"

The aim of this proof-of-concept study was to evaluate the in vitro effects of ozonated water treatment on the viability of oocysts and cysts isolated from naturally infected water buffaloes. oocysts were divided into seven groups of six replicates that were treated with ozonated water at three ozone concentrations (0.5, 1, and 2 mg/L) and two contact times (five and ten minutes), and one group (negative control) that was exposed to non-treated water.

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Anoplocephala perfoliata is the commonest equine tapeworm, the adult parasites are attached in groups close to the ileocaecal valve causing marked inflammatory pathology. This work aimed to characterize the nature of the in vivo mucosal immune response to A perfoliata, and to investigate the role of A perfoliata excretory-secretory components in modulating in vitro immune responses. Real-time PCR detected elevation of IL13 and TGFβ transcription in early-stage A perfoliata infection.

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Background: Nematode infections in horses are widespread across the world. Increasing levels of anthelmintic resistance, reported worldwide in equine parasites, have led to the creation of programs for the control of nematodes based on faecal egg counts (FEC). To improve nematode egg counting in equine faecal samples and establish whether the matrix of equine faeces or the eggs affect the counts, the analytical sensitivity, accuracy and precision of Mini-FLOTAC (combined with Fill-FLOTAC), McMaster and Cornell-Wisconsin techniques were compared.

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Background: Trematode infections of livestock are of global veterinary and public health importance causing serious economic losses. Majority of data on burden of trematode infections in Nigeria are based on abattoir surveys and there are very few data on herd level risk factors. The present study investigated the prevalence of, and herd level risk factors for, fasciolosis and other trematode infections in cattle in Edu Local Government Area (LGA).

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The epidemiology of trematode infections in cattle was investigated within highland and lowland areas of Iringa Rural District, in southern Tanzania. Fecal samples were collected from 450 cattle in 15 villages at altitudes ranging from 696 to 1800 m above the sea level. Freshwater snails were collected from selected water bodies and screened for emergence of cercariae.

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Three methods, FLOTAC, FECPAK and McMaster were compared for accuracy and sensitivity for counting numbers of nematode eggs in faeces of naturally infected cattle with high or low nematode egg counts. Only FLOTAC gave positive results for 12 replicates from pooled samples with low egg counts making it more sensitive than FECPAK (67%) and McMaster (41.7%).

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Background: The most common intestinal nematodes of dogs are Toxocara canis, hookworm and Trichuris vulpis. The present study was aimed to validate a new copromicroscopic technique, the Mini-FLOTAC and to compare its diagnostic efficiency and sensitivity with four other copromicroscopic techniques: direct smear, tube flotation, Wisconsin method and the FLOTAC dual technique.

Findings: Two experiments were performed.

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Background: The relationship between the environment and infection of cattle with trematodes was studied at Arumeru District, Arusha Region, northern Tanzania. Randomly selected villages were grouped into three cattle management strata, (i) zero-grazing (ZZ) (ii) communal grazing without irrigation (ZC) and (iii) communal grazing with irrigation (ZCI).

Methods: Faecal samples were collected from 241 cattle, and processed using the Flukefinder method.

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To determine how far management practices on small ruminant dairy flocks in southern Italy have influenced the development of anthelmintic resistance (AR), faecal egg count (FEC) reduction tests were run on 54 sheep farms using the FLOTAC technique with a sensitivity of 2 eggs per gram of faeces. Tests were run on groups of sheep (12-20 animals per group) using six anthelmintics administered orally: levamisole on 8 farms, ivermectin (half and full dose) on 8 farms, moxidectin on 3 farms, monepantel on 8 farms, netobimin on 22 farms (pooled samples) and albendazole on 5 farms (pooled samples). Different formulae and statistics were used to calculate FEC reductions and confidence intervals based on the presence of a control group and/or the use of pooled samples.

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Infection of horses with Anoplocephala perfoliata induces a severe inflammatory reaction of the caecal mucosa around the site of parasite attachment adjacent to the ileocecal valve. Lesions show epithelial erosion or ulceration of the mucosa with infiltration by eosinophils, lymphocytes and mast cells leading to oedema, gross thickening and fibrosis of the caecal wall. Despite this evidence of an inflammatory reaction to A.

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Dihydroartemisinin, formerly known as an antimalarial drug, is the main metabolite of the mother compound artemisinins, as well as of artemether and artesunate. It has been shown that the drug exhibits antischistosomal efficacy against Schistosoma japonicum. The purpose of the current study was to assess the in vivo effect of dihydroartemisinin against Schistosoma mansoni infection in mice.

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As a new suspension concentrate of niclosamide (SCN) was more effective in controlling Oncomelania snails than a wettable powder of the same drug, it was tested against Biomphalaria glabrata. There were no differences in the effect of the suspension concentrate, the wettable powder of niclosamide and ball-milled pure niclosamide against the adult snails, but at after 48h 0.125mg/l SCN killed 100% of eggs compared with 84.

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The ability to reliably detect anthelmintic resistance is a crucial part of resistance management. If data between countries are to be compared, the same test should give the same results in each laboratory. As the egg hatch test for benzimidazole resistance is used for both research and surveys, the ability of different laboratories to obtain similar results was studied through testing of known isolates of cyathostomins, Haemonchus contortus, Ostertagia ostertagi, and Cooperia oncophora in programs supported by the EU (Cost B16 and FP6-PARASOL).

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Despite the limited reports of praziquantel resistance, the relative success of chemotherapy-based control programmes for schistosomiasis has prompted overdue efforts to expand the use of cheap, generic, praziquantel in sub-Saharan Africa. The likely impact of such programmes on the development and spread of praziquantel resistance is uncertain, but this possibility reinforces the need for monitoring the spectrum of praziquantel sensitivity of schistosome populations and for an improved knowledge of the precise targets for the action of the drug. The search for alternatives to praziquantel and other tools for control of schistosomiasis must continue.

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To determine the genetic basis of the resistance of Schistosoma mansoni to praziquantel (PZQ) and to understand whether the resistance is dominant or recessive trait, a schistosome cross was undertaken between a PZQ-susceptible and a PZQ-resistant isolate using infections of the single-sex cercariae which were identified by a direct W1-specific PCR technique. The resistances of F1 and F2 generation to PZQ were evaluated using in vitro egg, miracidial and cercarial tests. The F1 hybrid progeny from crosses between the susceptible and resistant isolates were resistant to PZQ.

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Evidence for resistance to praziquantel (PZQ) in Schistosoma mansoni has been sought in parasites taken from treated, but uncured human patients, and in a laboratory isolate of S. mansoni subjected to successive passages under drug pressure. Patients from villages in Egypt and Senegal have yielded isolates that can tolerate higher dosages of PZQ than other ostensible control isolates when passaged and subjected to drug treatment in mice.

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