Genetic diversity patterns of Haemonchus placei and Haemonchus contortus populations isolated from domestic ruminants in Brazil

Brasil, Bruno S. A. F.; Nunes, Ronaldo Luiz; Bastianetto, Eduardo; Drummond, Marcela Gonçalves; Carvalho, Daniel C.; Leite, Romário Cerqueira; Molento, Marcelo Beltrão; Oliveira, Denise Aparecida Andrade de

doi:10.1016/j.ijpara.2012.03.003

Cited by 92 publications

(115 citation statements)

References 54 publications

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“…In Brazil, Nunes et al (2013) evaluated goat, sheep and buffalo herds with respect to the presence of polymorphism which confers resistance to benzimidazole, and stated that molecular diagnosis is the guide of choice for anthelmintic drugs before they are used on the herd. Studies of molecular tests on AHR in Brazil have also been evaluated, involving testing of beta-tubulin mutations or genetic evaluations of nematodes, corroborating researches into AHR (SILVA et al, 2015;SANTOS et al, 2014;AMARANTE et al, 2014;BRASIL et al, 2012).…”

Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

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Frequent and inappropriate use of all classes of antiparasitic drugs in small ruminants has led to failures in their effectiveness, culminating in a global problem of anthelmintic resistance. Brazil stands out as one of the world's leaders in publications about anthelmintic resistance, and for having the most numerous reports of this resistance in small ruminants in the Americas. These studies have involved mainly the fecal egg count reduction test (FECRT) and its correlation with field management practices. In vivo effectiveness testing is conducted in areas where livestock is of greater economic significance, e.g., in the South (sheep) and Northeast (goats), or is important for research and economic centers, such as the Southeast (sheep). The most widely studied species is sheep, for which the widest range of drugs is also evaluated. Despite significant advances achieved in molecular research, laboratory analyses should include knowledge about the reality in the field so that they can become feasible for the producer. Moreover, molecular studies can be underpinned by the analysis of field studies, such as the maintenance of antiparasitic effectiveness over time and the mechanisms involved in this process.Keywords: Small ruminants, anthelmintic resistance, sheep, goat, gastrointestinal nematodes. ResumoO uso frequente e inapropriado de todas as classes de antiparasitários em pequenos ruminantes levou a falhas de eficácia, culminando na problemática global de resistência anti-helmíntica. O Brasil destaca-se como sendo um dos pioneiros nas publicações com resistência anti-helmíntica no mundo e por ter o maior número de relatos em pequenos ruminantes na América. Essas pesquisas envolvem principalmente o teste da redução da contagem de ovos nas fezes (TRCOF) e sua correlação com as práticas de manejo utilizadas no campo. Os estudos de testes de eficácia in vivo localizam-se em áreas onde há maior importância dos rebanhos como nas Regiões Sul (ovinos) e Nordeste (caprinos), ou com importância em polos de pesquisa e econômicos, como a região Sudeste (ovinos). Ovina é a espécie mais estudada e com maior gama de drogas avaliadas. Mesmo com grande avanço em pesquisas moleculares, as análises laboratoriais devem envolver o conhecimento da realidade do campo para que possam se tornar viáveis ao produtor. Além disso, a análise dos estudos de campo pode nortear estudos moleculares como, por exemplo, a manutenção da eficácia das drogas ao longo dos anos e os mecanismos envolvidos em tal processo.

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Section: Diagnostic Methods Employed In Brazil To Detect Ahr In Smallmentioning

confidence: 99%

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

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“…Differences in the morphology of the infective larvae (L3) have also been reported, with H. placei L3s longer, more robust, and with longer sheath tail than those of H. contortus (SANTIAGO, 1968;VAN WYK et al, 2004). There are also several approaches using molecular techniques that can be employed do differentiate H. placei from H. contortus, including the use of PCR primers to amplify ribosomal RNA genes (ZARLENGA et al, 1994), and differences in mitochondrial ND4 gene sequences (BLOUIN et al, 1997) and in the ribosomal DNA second internal transcribed spacer sequences (STEVENSON et al, 1995;BRASIL et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Differentiation of Haemonchus placei from Haemonchus contortus by PCR and by morphometrics of adult parasites and third stage larvae

Santos

Amarante

Silva

et al. 2014

Rev. Bras. Parasitol. Vet.

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Molecular and morphological methods were evaluated to distinguish between Haemonchus contortus and Haemonchus placei species. A total of 141 H. contortus and 89 H. placei male adult specimens collected from artificially infected lambs were identified individually by PCR analysis, using a species-specific primer pair. These PCR results were used as gold standard for Haemonchus spp. identification. Haemonchus placei presented higher mean spicule and barb lengths than H. contortus (P<0.05). However, some measurements overlapped. For this reason, a discriminate function did not allow the correct identification of 13 H. contortus and one H. placei specimen. The sheath tail length of the third stage larvae (L3), which comprises the distance between the tip of the larval tail and the end of the sheath tail, were measured. Only three of the 485 H. placei larvae (0.619%) had a sheath tail shorter than 85 µm, while only four of the 500 H. contortus larvae (0.8%) presented a sheath tail longer than 85 µm. The results indicated that 6.09% of the male adult specimens would be misclassified based on the discriminate function, while only 0.71% of infective larvae would be misclassified. Therefore, identification of L3 can be used as the first method to indicate the presence of H. placei and/ or H. contortus in a population of domestic ruminants.Keywords: Diagnosis, Trichostrongyloidea, molecular biology, ruminants, epidemiology. ResumoMétodos moleculares e morfológicos foram avaliados para a identificação de Haemonchus contortus e Haemonchus placei. No total, 141 H. contortus e 89 H. placei machos adultos, obtidos de cordeiros artificialmente infectados, foram identificados individualmente por PCR com o emprego de um par de "primers" espécie-específico. Esses resultados da análise por PCR foram considerados como padrão para a identificação das espécies de Haemonchus. Haemonchus placei apresentou valores médios de espículos e ganchos superiores aos de H. contortus (P<0,05). Entretanto, houve sobreposição de alguns valores. Por essa razão, a função discriminante não permitiu a identificação correta de 13 exemplares de H. contortus e de um, de H. placei. Foi medida a cauda da bainha de larvas infectantes (L3), que compreende a distância entre a ponta da cauda da larva e a ponta da cauda da bainha. Apenas três das 485 L3 de H. placei (0,619%) apresentaram a cauda da bainha com medida inferior a 85 µm e somente em quatro das 500 L3 de H. contortus (0,8%) essa medida foi superior a 85 µm. Os resultados demonstraram que 6,09% dos machos adultos seriam identificados erroneamente com base na função discriminante, enquanto a identificação incorreta de L3 seria de apenas 0,71%. Portanto, a identificação de L3 pode ser utilizada como método inicial para indicar a presença de H. placei e/ou H. contortus em uma população de ruminantes domésticos.

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“…Gastrointestinal nematodes are the most prevalent and major parasites in domestic and wild ruminants in tropical, subtropical and temperate regions worldwide [1,2] . One of the highly dangerous and economically important of these nematodes is Haemonchus contortus which is also known as "barber pole worm" and an abomasal pathogen of sheep [3] .…”

Section: Introductionmentioning

confidence: 99%

“…One of the highly dangerous and economically important of these nematodes is Haemonchus contortus which is also known as "barber pole worm" and an abomasal pathogen of sheep [3] . It causes anemia, stunted growth, weight loss, loss in protein, disorder in fertility, decrease in milk, meat and wool production and the last death if untreated [1] .  İletişim (Correspondence)  +90 553 2543525  zuhalbiskin@erciyes.edu.tr…”

Section: Introductionmentioning

confidence: 99%

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Koyunlarda Haemonchus contortus’un Moleküler Prevalansı, Filogenetik Karakterizasyonu ve Benzimidazol Dirençliliği

Önder¹,

Yıldırım²,

İncı³

et al. 2015

Kafkas Univ Vet Fak Derg

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This study was conducted to determine the molecular prevalence and characterization of Haemonchus contortus from sheep along with the benzimidazole (BZ) resistance in H. contortus populations. Fecal samples were collected from a total of 300 sheep in research area and analyzed by fecal flotation. qPCR assays were utilized on trichostrongylid egg positive samples in order to identify H. contortus. Phylogenetic analyses were performed on ribosomal ITS-2 and mt-COI gene regions. BZ sensitive and resistant allele frequencies were determined by qPCR along with sequence analyses of the β-tubulin isotype 1 gene for single nucleotide polimorphizms (SNPs). H. contortus was identified in 36 (24.8%) out of 145 trichostrongylid egg positive samples. H. contortus isolates showed 100.0% identity to each other and 0.1% difference with the isolates available in the GenBank based on phylogenetic analyses of ITS-2 gene while mt-COI analyses of the isolates exhibited a mean of 97.4±0.5% identity to each other and 5.5±0.8% difference with the isolates in GenBank. BZ sensitive and resistant allele frequencies in H. contortus populations were determined as 87.1%±16.2 and 12.9%±16.2, respectively. SNPs were detected only in the codon 200 of the sequenced isolates belong to resistant allele. This study provides the first data on molecular prevalence, phylogenetic characterization and BZ resistance in H. contortus populations from sheep in Turkey. Keywords

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Genetic diversity patterns of Haemonchus placei and Haemonchus contortus populations isolated from domestic ruminants in Brazil

Cited by 92 publications

References 54 publications

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Differentiation of Haemonchus placei from Haemonchus contortus by PCR and by morphometrics of adult parasites and third stage larvae

Koyunlarda Haemonchus contortus’un Moleküler Prevalansı, Filogenetik Karakterizasyonu ve Benzimidazol Dirençliliği

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