MyMedR

Displaying all 6 publications

Abstract:

Sort:

Morphological variation between isolates of the nematode Haemonchus contortus from sheep and goat populations in Malaysia and Yemen

Gharamah AA, Rahman WA, Siti Azizah MN

J Helminthol, 2014 Mar;88(1):82-8.
PMID: 23176779 DOI: 10.1017/S0022149X12000776

Haemonchus contortus is a highly pathogenic nematode parasite of sheep and goats. This work was conducted to investigate the population and host variations of the parasitic nematode H. contortus of sheep and goats from Malaysia and Yemen. Eight morphological characters were investigated, namely the total body length, cervical papillae, right spicule, left spicule, right barb, left barb, gubernaculum and cuticular ridge (synlophe) pattern. Statistical analysis showed the presence of morphological variation between populations of H. contortus from Malaysia and Yemen, with minor variation in the synlophe pattern of these isolates. Isolates from each country were grouped together in the scatterplots with no host isolation. Body, cervical papillae and spicule lengths were the most important characters that distinguished between populations of the two countries. This variation between Malaysia and Yemen may be attributed to geographical isolation and the possible presence of a different isolate of this worm in each country.

Matched MeSH terms: Haemonchus/isolation & purification
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: Haemonchus/isolation & purification*
Isolation of an ivermectin-resistant strain of Haemonchus contortus from sheep in Malaysia

Sivaraj S, Pandey VS

Vet Rec, 1994 Sep 24;135(13):307-8.
PMID: 7817517
Matched MeSH terms: Haemonchus/isolation & purification*
Benzimidazole resistance of Haemonchus contortus in goats in Malaysia

Dorny P, Claerebout E, Vercruysse J, Jalila A, Sani R

Vet Rec, 1993 Oct 23;133(17):423-4.
PMID: 8279113
Matched MeSH terms: Haemonchus/isolation & purification
Fulltext Genetic variability within and among Haemonchus contortus isolates from goats and sheep in China

Yin F, Gasser RB, Li F, Bao M, Huang W, Zou F, et al.

Parasit Vectors, 2013 Sep 25;6(1):279.
PMID: 24499637 DOI: 10.1186/1756-3305-6-279

BACKGROUND: Haemonchus contortus (order Strongylida) is a common parasitic nematode infecting small ruminants and causing significant economic losses worldwide. Knowledge of genetic variation within and among H. contortus populations can provide a foundation for understanding transmission patterns, the spread of drug resistance alleles and might assist in the control of haemonchosis.
METHODS: 152 H. contortus individual adult worms were collected from seven different geographical regions in China. The second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA and mitochondrial nicotinamide dehydrogenase subunit 4 gene (nad4) were amplified by polymerase chain reaction (PCR) and sequenced directly. The sequence variations and population genetic diversities were determined.
RESULTS: Nucleotide sequence analyses revealed 18 genotypes (ITS-2) and 142 haplotypes (nad4) among the 152 worms, with nucleotide diversities of 2.6% and 0.027, respectively, consistent with previous reports from other countries, including Australia, Brazil, Germany, Italy, Malaysia, Sweden, the USA and Yemen. Population genetic analyses revealed that 92.4% of nucleotide variation was partitioned within populations; there was no genetic differentiation but a high gene flow among Chinese populations; some degree of genetic differentiation was inferred between some specimens from China and those from other countries.
CONCLUSIONS: This is the first study of genetic variation within H. contortus in China. The results revealed high within-population variations, low genetic differentiation and high gene flow among different populations of H. contortus in China. The present results could have implications for studying the epidemiology and ecology of H. contortus in China.

Matched MeSH terms: Haemonchus/isolation & purification
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: Haemonchus/isolation & purification