Studies on arrested development of Ostertagia ostertagi and Cooperia oncophora

Michel, J. F.; Lancaster, M.B.; Hong, C.

doi:10.1016/0021-9975(74)90046-2

Cited by 39 publications

(19 citation statements)

References 8 publications

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“…In the Middle-Atlas of Morocco, both winter and summer peaks of L4s were recorded over three consecutive years [ 7 ]. The L4 summer peaks in the present study did not correspond exactly to the classification of hypobiosis in trichostrongylid nematodes given that the L4s here were not found in the mucosa [ 27 ]. However, according to Michel [ 26 ], occurrence of hypobiosis can be indicated by one of the two factors: a) the presence of the same immature stage when there has been no sudden uptake of infective larvae, and b) the continued presence of immature stages after withdrawal from infection when sheep are kept in a sheep pen longer than the pre-patent period.…”

Section: Discussioncontrasting

confidence: 78%

“…The dynamics of the L4s (mostly T. circumcincta ) was also seasonal, reaching a peak in June to represent 48% of the total worm burden. At this time, the L4s were found in the abomasal contents and not in the mucosa, which is the usual situation of winter-arrested larvae [ 3 , 5 , 27 ]. Large numbers of summer-arrested larvae have also been found in Syria [ 18 ], where they represented 85% of the total worm burden, and other regions with a long dry summer, i.e.…”

Section: Discussionmentioning

confidence: 95%

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Arrested development of abomasal trichostrongylid nematodes in lambs in a steppe environment (North-Eastern Algeria)

2016

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Arrested development of abomasal trichostrongylid nematodes was studied in 30 permanent grazing lambs on a large farm in the North-East of Algeria. The steppe climate has cold winters and hot and dry summers. The lambs were monitored monthly for gastrointestinal nematodes using nematode faecal egg counts, from February 2008 to February 2009. Every 2 months, two of the original 30 permanent lambs were necropsied after being held in pens for three weeks so that recently ingested infective larvae could develop into adults. The highest percentage of fourth stage larvae (L4), reaching 48% of the total worm burden, was recorded in abomasal contents in June. Teladorsagia and other Ostertagiinae constituted the highest percentage of L4 larvae (71%), whereas the percentage of Trichostrongylus (17.4%) or Haemonchus (11.6%) remained low. The dynamics of infection observed here (highest faecal egg count in August) and the stage composition of worm burden (highest percentage of L4 in June) provide strong evidence that arrested development had occurred.

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Section: Discussioncontrasting

confidence: 78%

Section: Discussionmentioning

confidence: 95%

Arrested development of abomasal trichostrongylid nematodes in lambs in a steppe environment (North-Eastern Algeria)

2016

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“…The infective larvae, that are exposed to environmental stimuli, particularly low temperature, will inhibit development (Armour and Bruce 1974;Michel et al 1974Michel et al , 1975Watkins and Fernando 1984). Currently there are findings that suggest not only low temperatures but also photoperiod contributed to the arrested development of many nematode species.…”

Section: Methodsmentioning

confidence: 99%

Arrested development of sheep strongyles: onset and resumption under field conditions of Central Europe

et al. 2008

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Two tracer tests were conducted between August 2004 and March 2007 at an ecological farm in western Bohemia. The first tracer test was performed for the summer-autumn grazing period (onset of arrested development), the second for spring (resumption of arrested development). In the first tracer test, the percentage of nematodes arresting development over the winter months reached 87.7% for Teladorsagia circumcincta, 66.7% for Haemonchus contortus, 89.9% for Nematodirus filicollis, 21.6% for Trichostrongylus axei, and 23.9% for both Trichostrongylus vitrinus and Trichostrongylus colubriformis. None of the arrested larvae were observed with species Cooperia curticei, Nematodirus battus, and Oesophagostomum venulosum. In the second tracer test, a significant increase of adult worms was discovered in March of species T. circumcincta and N. filicollis and Trichostrongylus spp. in February. Redundancy analysis and generalized linear models analyses have confirmed that environmental conditions play a crucial role in hypobiosis of sheep strongyles in the Czech Republic. The analysis of influences of various environmental factors revealed that the number of arrested larvae was negatively influenced by light-day length, sunshine, or daylight decrease (p < 0.01).

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“…In order to examine variation in infection levels reported by the mobile laboratory, the climate of these study locations should be monitored in correspondence with the latency periods of O. petrowi and A. pennula. Additionally, it is based on these climatic variations as to when these parasites may enter a stage of diapause (Fernando et al, 1971;Michel et al, 1974Michel et al, , 1975Michel et al, , 1976, making it harder to treat these parasites due to reduced energy requirements at this time (Pritchard et al, 1978;Sommerville and Davey, 2002). These seasonal factors may also heavily influence the insect intermediate host populations of both parasites.…”

Section: Discussionmentioning

confidence: 99%

Regional surveillance of parasitic infections in wild Northern Bobwhite Quail (Colinus virginianus) utilizing a mobile research laboratory platform

et al. 2018

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Northern bobwhite quail (Colinus virginianus), a popular gamebird among hunters, have been declining over recent decades in the Rolling Plains ecoregion. Investigations in the past few years have revealed a high prevalence of eyeworms (Oxyspirura petrowi) and caecal worms (Aulonocephalus pennula) in this ecoregion, prompting a need to better understand their host–parasite interaction and other factors that influence infection. In this study, the efficiency of a mobile laboratory was tested by deploying it to three field sites in the Rolling Plains between July and August of 2017 and collecting cloacal swabs from bobwhites. The DNA was extracted from swabs for quantitative PCR and was run in the mobile and reference laboratory to specifically detectA. pennulaandO. petrowiinfection. When compared with the Wildlife Toxicology's reference laboratory, the mobile laboratory had a 97 and 99% agreement forA. pennulaandO. petrowi, respectively. There were no significant differences in infection levels between field sites. Due to its efficiency, it is proposed that the mobile laboratory would be an effective way to monitor infection levels, in addition to factors that may affect infection such as climate, diapause, and intermediate host populations.

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Studies on arrested development of Ostertagia ostertagi and Cooperia oncophora

Cited by 39 publications

References 8 publications

Arrested development of abomasal trichostrongylid nematodes in lambs in a steppe environment (North-Eastern Algeria)

Arrested development of abomasal trichostrongylid nematodes in lambs in a steppe environment (North-Eastern Algeria)

Arrested development of sheep strongyles: onset and resumption under field conditions of Central Europe

Regional surveillance of parasitic infections in wild Northern Bobwhite Quail (Colinus virginianus) utilizing a mobile research laboratory platform

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