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The establishment and development of Trichostrongylus colubriformis in goats

Rahman WA, Collins GH

Vet Parasitol, 1990 Mar;35(3):195-200.
PMID: 2343537

Twelve goats were inoculated with 20,000 infective larvae of Trichostrongylus colubriformis and two were killed on each of Days 4, 7, 11, 14, 18 and 21 after inoculation (DAI). The number of worms that established, and the site of development were recorded. Most of the worms established within the first 3 m of the small intestine. There was little relocation or loss of nematodes after establishment. The worms started to migrate from the mucosa to the lumen 11 days after infection. At 4 DAI, 63% of the worms were still at the late L3 stage; the remainder of the worm population had completed the third moult to the L4 stage. The population at 11 DAI comprised largely young adults. When 21 DAI was reached, about 57% of the female worms had eggs in their uteri.

Matched MeSH terms: Trichostrongylus/growth & development*
Epidemiology of gastro-intestinal nematodes of sheep in wet tropical conditions in Malaysia

Cheah TS, Rajamanickam C

Trop Anim Health Prod, 1997 Aug;29(3):165-73.
PMID: 9316233

A study on the seasonal variations in the population structure of Haemonchus contortus and Trichostronglyus colubriformis was conducted for a period of 12 months in a typical large scale sheep farm on improved pasture in Peninsular Malaysia which has a wet tropical climate. Successive groups of helminth-free tracer lambs were grazed for 4 weeks together with naturally infected sheep and were necropised for worm counts 2 weeks after their removal from the pasture. The monthly populations of H. contortus fluctuated slightly except in May and August during which more worms were found in the tracer animals. The numbers of T. colubriformis were comparatively high from October to December 1992 and again in March 1993, low during April and June 1992. Small numbers of hypobiotic larvae of H. contortus were detected in the tracer animals. Development and survival of infective larvae of H. contortus and T. colubriformis on pasture were investigated by spreading faeces containing eggs on grass plots in October 1993, February and May 1994. Development of the eggs to the infective larvae occurred within one week and their survival times were 7 weeks in the 3 experiments. The potential for control by rotational grazing is discussed.

Matched MeSH terms: Trichostrongylus/growth & development; Trichostrongylus/isolation & purification
Nematode control failure due to anthelmintic resistance in a sheep farm in Malaysia: First identification of the F200Y mutation in the isotype 1 β-tubulin gene

Khadijah S, Wahaf ANS, Syahmi MI, Tan TK, Low VL, Azrul LM, et al.

Trop Biomed, 2018 Dec 01;35(4):999-1006.
PMID: 33601847

This paper reports total nematode anthelmintic resistance towards albendazole, fenbendazole, levamisole and ivermectin in a commercial sheep farm located in Terengganu, Malaysia. Faecal Egg Count Reduction Test (FECRT) was conducted on 25 sheep, where five sheep in each group were treated with the respective four anthelmintics based on live bodyweight. The balance of five sheep placed in the control group were not treated with any anthelmintics. At day 13 post-treatment, faecal egg count was conducted and nematode worm egg count reduction percentage was calculated to determine the resistance status towards the respective anthelmintics tested. Results showed that nematodes were resistant to all the anthelmintics tested, namely albendazole, fenbendazole, levamisole and ivermectin with reduction percentage of 87%, 46%, 94% and 68%, respectively. Subsequently, the third stage larvae of Haemonchus contortus and Trichostrongylus colubriformis recovered from post-treatment faecal cultures were subjected to allele-specific polymerase chain reaction (AS-PCR) assay to determine the presence of the benzimidazole resistance gene. This study reports the occurrence of the classical F200Y mutation in the isotype 1 βtubulin gene, for the first time in Malaysia.

Matched MeSH terms: Trichostrongylus
Fulltext Co-infection of Haemonchus contortus and Trichostrongylus spp. among livestock in Malaysia as revealed by amplification and sequencing of the internal transcribed spacer II DNA region

Tan TK, Panchadcharam C, Low VL, Lee SC, Ngui R, Sharma RS, et al.

BMC Vet Res, 2014;10:38.
PMID: 24502557 DOI: 10.1186/1746-6148-10-38

Haemonchus contortus and Trichostrongylus spp. are reported to be the most prevalent and highly pathogenic parasites in livestock, particularly in small ruminants. However, the routine conventional tool used in Malaysia could not differentiate the species accurately and therefore limiting the understanding of the co-infections between these two genera among livestock in Malaysia. This study is the first attempt to identify the strongylids of veterinary importance in Malaysia (i.e., H. contortus and Trichostrongylus spp.) by amplification and sequencing of the Internal Transcribed Spacer II DNA region.

Matched MeSH terms: Trichostrongylus/isolation & purification*
Survey for drug-resistant trichostrongyle nematodes in ten commercial goat farms in west Malaysia

Rahman WA

Trop Anim Health Prod, 1994 Nov;26(4):235-8.
PMID: 7900221

The prevalence of drug-resistant parasites in goats in West Malaysia has rarely been reported. Ten commercial goat farms were surveyed for resistance to anthelminthics by measuring the reduction in faecal egg counts (FECs) after treatment with levamisole, pyrantel pamoate and fenbendazole. Resistance to fenbendazole was seen in most farms; there was no evidence of resistance to levamisole but some resistance to pyrantel pamoate was detected on one farm. The significance of the findings are discussed.

Matched MeSH terms: Trichostrongylus/drug effects
Seasonal variations in the populations of infective larvae on pasture and the numbers of nematode eggs in the faeces of farmed goats

Rahman WA, Collins GH

J Helminthol, 1990 Sep;64(3):263-70.
PMID: 2230037

The levels of nematode egg production in goats and the availability of infective larvae (L3) on pasture were investigated on a dairy unit in New South Wales, Australia. The output of eggs by adult goats was always above 300 epg. The profile of the graph of larval availability in herbage paralleled those for temperature and rainfall, suggesting that larval peaks occurred when the temperature and availability of moisture were optimal. The dominant genus was Trichostrongylus, followed by Haemonchus, then Ostertagia. A larger proportion of Haemonchus larvae in the cultures of faeces were collected during the summer months.

Matched MeSH terms: Trichostrongylus/growth & development
In vitro ovicidal and larvicidal activity of methanolic leaf extract of Manihot esculenta (cassava) on susceptible and resistant strains of Trichostrongylus colubriformis

Al-Rofaai A, Rahman WA, Sulaiman SF, Yahaya ZS

Vet Parasitol, 2012 Nov 23;190(1-2):127-35.
PMID: 22749290 DOI: 10.1016/j.vetpar.2012.05.028

This study aimed to represent the first report of the ovicidal and larvicidal activity of the methanolic leaf extract of Manihot esculenta (cassava) against eggs and larvae of susceptible and resistant strains of Trichostrongylus colubriformis. As well as, to determine the total tannin compounds, antioxidant activity and toxicity of the extract. The egg hatch test was used to evaluate ovicidal activity against unembryonated eggs, whereas larval feeding inhibition assay and MTT-formazan assay were used to evaluate larvicidal activity against first (L(1)) and infective (L(3)) larvae, respectively. The results showed no significant differences were detected between the sensitivities of susceptible and resistant strains of T. colubriformis to the extract. Eggs, L(1) and L(3) were significantly affected (P<0.001) compared with negative control, and L(1) were more sensitive than the eggs and L(3). The total tannin compounds were investigated using tannin quantification assay and determined by 254.44 TAE/mg. The antioxidant activity was evaluated using the DPPH radical scavenging assay and the median inhibition concentration (IC(50)) was determined by 2.638 mg/ml. Acute oral toxicity at dose of 5,000 mg/kg, and sub-chronic oral toxicity at 500 and 1,000 mg/kg of the extract were observed in male and female Sprague-Dawley (SD) rats. The acute oral toxicity revealed that the median lethal dose (LD(50)) of methanolic extract of cassava leaves on SD rats was greater than 5,000 mg/kg, whereas the sub-chronic oral toxicity did not show observed adverse effects at 500 and 1,000 mg/kg per day for 28 days. In conclusion, the methanolic extract of cassava leaves has direct ovicidal and larvicidal activity against T. colubriformis strains with a safety margin for animals, and it may be potentially utilized as a source of natural antioxidants.

Matched MeSH terms: Trichostrongylus/drug effects*
Multiple and multigeneric anthelmintic resistance on a sheep farm in Malaysia

Sivaraj S, Dorny P, Vercruysse J, Pandey VS

Vet Parasitol, 1994 Oct;55(1-2):159-65.
PMID: 7886917

The anthelmintic efficacy of benzimidazoles, levamisole, closantel, ivermectin and moxidectin was evaluated on an institutional farm in Malaysia using faecal egg count reduction tests, controlled slaughter trials and an in vitro egg hatch assay. The results of this study indicated simultaneous resistance of Haemonchus contortus against benzimidazoles and ivermectin and of Trichostrongylus colubriformis against benzimidazoles and levaminsole on the same farm. Moxidectin was effective against the ivermectin resistant H. contortus.

Matched MeSH terms: Trichostrongylus/drug effects
Kinetics of IgA and eosinophils following a low-dose, predominantly Haemonchus contortus infection of Boer goats

Hayyan BN, Sharma RSK, Raimy N, Nisha M, Hussain K, Busin VM, et al.

Parasite Immunol., 2020 06;42(6):e12707.
PMID: 32118305 DOI: 10.1111/pim.12707

AIMS: Most breeds of goat are more susceptible to nematode infection than sheep, and this appears to be a consequence of less effective immune responses. Several papers have considered the effectiveness of eosinophils and immunoglobulin A (IgA) in goats but differences in the induction of responses have not been studied in the same detail. The aim of this study was to look at the induction of eosinophil and IgA responses in Boer goats reared indoors under intensive conditions.
METHODS AND RESULTS: The goats were experimentally infected with a low dose of 2400 Haemonchus contortus, Trichostrongylus spp. and Oesophagostomum spp. at a 6:1:1 ratio. Faecal egg counts (FEC), packed cell volume (PCV), IgA activity against third-stage larvae and peripheral eosinophilia were measured twice a week for eight weeks. The infection generated an IgA response but did not significantly increase peripheral eosinophilia in the 25 infected kids compared with the 4 control animals. FEC was not associated with IgA activity or eosinophilia.
CONCLUSION: A detailed analysis of IgA and eosinophil responses to deliberate nematode infection in Boer goats showed that there was an increase in nematode-specific IgA activity but no detectable eosinophil response. In addition, there was no association between increased IgA activity or eosinophilia with egg counts and worm burdens. These suggest that IgA and eosinophils do not act to control nematode infection in goats.

Matched MeSH terms: Trichostrongylus/immunology