Establishment of co-infection and hybridization of Haemonchus contortus and Haemonchus placei in sheep

2018 ◽  
Vol 93 (6) ◽  
pp. 697-703 ◽  
Author(s):  
M.C. Santos ◽  
M.R.V. Amarante ◽  
A.F.T. Amarante

AbstractThis study aimed to evaluate the simultaneous infections of Haemonchus contortus and Haemonchus placei in sheep, as well as the production of hybrids. A parental group of lambs (n = 6) were mix-infected with 2000 infective larvae (L3) of H. placei and 2000 L3 of H. contortus. Faecal samples were taken from each of these six lambs to produce the first generation of L3 (F1-L3) in individual cultures. These F1-L3 were used to infect 12 lambs; six of them were euthanized at 42 days (Group F1-42) and six at 84 days (Group F1-84) post infection. Polymerase chain reaction (PCR) analysis, using species-specific primer pairs, was the gold standard method for identification of Haemonchus adult species and hybrids. The establishment rate of both species was similar in the parental group: 51.7% H. contortus and 48.3% H. placei. Of the 219 adult specimens from groups F1-42 and F1-84 analysed by PCR, eight (3.65%) were hybrids, 111 were H. contortus and 100 were H. placei. The morphological evaluation of the F1-L3 from the parental group showed a predominance of larvae with H. contortus size (51.5%) in comparison with H. placei (42.8%). In the second generation of L3 (F2-L3) produced by the F1-lambs, larvae with H. contortus morphology predominated, with 81.5% in the F1-42 group and 84.0% in the F1-84 group. In conclusion, an artificial mixed infection by H. contortus and H. placei was established in lambs and resulted in the production of a small number of hybrids among their offspring.

2014 ◽  
Vol 23 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Michelle Cardoso dos Santos ◽  
Mônica Regina Vendrame Amarante ◽  
Maria Regina Lucas da Silva ◽  
Alessandro Francisco Talamini do Amarante

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.


2017 ◽  
Vol 91 (6) ◽  
pp. 757-761 ◽  
Author(s):  
M.R.V. Amarante ◽  
M.C. Santos ◽  
C.C. Bassetto ◽  
A.F.T. Amarante

AbstractHaemonchus contortus and Haemonchus placei are among the major parasites of small ruminants and cattle. Although infection with these nematodes is host-specific, with H. placei predominating in cattle and H. contortus in sheep, cross-infections are observed in areas where both parasites are sympatric, and hybrid offspring can occur. Therefore, a fast and precise method is required for differentiating the parasites. Identification based on spicule morphometry is the most common technique for differentiating Haemonchus species. However, because these measurements overlap between species, morphological analysis is insufficient for differentiating between helminth species. In this work, we present a reliable, conventional polymerase chain reaction (PCR)-based method that uses two species-specific primer pairs to differentiate between H. contortus and H. placei specimens and their hybrids. Each primer pair produces one single and distinct amplification band for each species, which enables the detection of hybrid specimens. These primer pairs were validated by testing eight different populations of H. contortus, H. placei and hybrids.


Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 398
Author(s):  
Meruyert Beknazarova ◽  
Harriet Whiley ◽  
Rebecca Traub ◽  
Kirstin Ross

Both Strongyloides stercoralis and hookworms are common soil-transmitted helminths in remote Australian communities. In addition to infecting humans, S. stercoralis and some species of hookworms infect canids and therefore present both environmental and zoonotic sources of transmission to humans. Currently, there is limited information available on the prevalence of hookworms and S. stercoralis infections in dogs living in communities across the Northern Territory in Australia. In this study, 274 dog faecal samples and 11 faecal samples of unknown origin were collected from the environment and directly from animals across 27 remote communities in Northern and Central Australia. Samples were examined using real-time polymerase chain reaction (PCR) analysis for the presence of S. stercoralis and four hookworm species: Ancylostoma caninum, Ancylostoma ceylanicum, Ancylostoma braziliense and Uncinaria stenocephala. The prevalence of S. stercoralis in dogs was found to be 21.9% (60/274). A. caninum was the only hookworm detected in the dog samples, with a prevalence of 31.4% (86/274). This study provides an insight into the prevalence of S. stercoralis and hookworms in dogs and informs future intervention and prevention strategies aimed at controlling these parasites in both dogs and humans. A “One Health” approach is crucial for the prevention of these diseases in Australia.


2018 ◽  
Vol 93 (3) ◽  
pp. 313-318 ◽  
Author(s):  
A. Merino-Tejedor ◽  
P. Nejsum ◽  
E.M. Mkupasi ◽  
M.V. Johansen ◽  
Annette Olsen

AbstractThe presence and distribution of various species of canine hookworms in Africa are poorly known. The main objective of this study, therefore, was to identify the hookworm species present in canine faecal samples from Morogoro, Tanzania, using molecular techniques. Faecal samples from 160 local dogs were collected and hookworm positive samples processed to recover larvae for further molecular characterization. DNA was extracted from pools of larvae from individual samples (n = 66), which were analysed subsequently using two different molecular approaches, polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) and species-specific PCR coupled with Sanger sequencing. The PCR-RFLP technique detected only the presence of the ubiquitousAncylostoma caninumin the 66 samples. However, by species-specific PCR coupled with Sanger sequencing we identified ten samples withA. braziliense, two withUncinaria stenocephalaand five withA. ceylanicum. Thus, all four known species of canine hookworms were identified in Morogoro, Tanzania. To our knowledge this is the first report of the detection of the presence ofU. stenocephalaandA. ceylanicumin Africa using molecular techniques. In addition to their veterinary importance, canine hookworms have zoonotic potential and are of public health concern.


2014 ◽  
Vol 142 (12) ◽  
pp. 2542-2547 ◽  
Author(s):  
A. SANNÖ ◽  
A. ASPÁN ◽  
G. HESTVIK ◽  
M. JACOBSON

SUMMARYThe European wild boar populations are growing and spreading to new areas, which might constitute a threat to public health, since wild boar can harbour pathogens with the potential to cause serious illness in humans. Tonsils, ileocaecal lymph nodes and faecal samples were collected from 88 Swedish wild boars and analysed for the presence of the zoonotic pathogensSalmonellaspp.,Yersinia enterocolitica, Y. pseudotuberculosisand enterohaemorrhagicEscherichia coliO157:H7 (EHEC). A combination of cultivation and polymerase chain reaction (PCR) analysis was used and overall, 20% of sampled individuals tested positive forY. enterocolitica, 20% forY. pseudotuberculosisand 10% forSalmonellaspp. A total of 41% of sampled individuals tested positive for one or more of these three pathogens. No EHEC were detected. Samples PCR-positive forSalmonellaspp. were cultivated further and six isolates were obtained, belonging toSalmonella entericasubspeciesentericaand subspeciesdiarizone. The pathogens were most commonly detected in tonsil samples.


2017 ◽  
Vol 92 (1) ◽  
pp. 17-21 ◽  
Author(s):  
S.R. Mirbadie ◽  
H. Kamyabi ◽  
M.A. Mohammadi ◽  
S. Shamsaddini ◽  
M.F. Harandi

AbstractThe main objective of this study was to determine the prevalence of taeniid parasites and the specific detection of Echinococcus granulosus using copro-DNA polymerase chain reaction (PCR) analysis in the stray dogs of Kerman, south-eastern Iran. From September 2013 to May 2014, faecal samples of stray dogs were collected from different parts of the city of Kerman and its suburbs. Faecal samples from dogs were collected randomly within 24 h of defecation. All samples were transferred to the research lab and coprological examinations were conducted by the formalin–ether concentration method. In the microscopically positive samples, mitochondrial cytochrome c oxidase subunit 1 (cox1) specific primers were used to determine the taeniid identity of the infection. In addition, another set of primers was used for the specific diagnosis of E. granulosus sensu lato. In total, 307 faecal samples from stray dogs were examined for the presence of the parasites. Taeniidae eggs were detected in 34 dogs (11.07%). All 34 taeniid-positive specimens were PCR positive for cox1 (444 bp). Of all taeniid-positive specimens, 21 samples (6.8% of all dog specimens) were positive according to primers specific for E. granulosus. The findings of the present study revealed that canine echinococcosis is prevalent in the stray dogs in Kerman. The findings of the present study have important implications for hydatid control programmes in the area.


2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Oleg S. Alexandrov ◽  
Olga V. Razumova ◽  
Gennady I. Karlov

5S rDNA is organized as a cluster of tandemly repeated monomers that consist of the conservative 120 bp coding part and non-transcribed spacers (NTSs) with different lengths and sequences among different species. The polymorphism in the 5S rDNA NTSs of closely related species is interesting for phylogenetic and evolutional investigations, as well as for the development of molecular markers. In this study, the 5S rDNA NTSs were amplified with universal 5S1/5S2 primers in some species of the Elaeagnaceae Adans. family. The polymerase chain reaction (PCR) products of five Elaeagnus species had similar lengths near 310 bp and were different from Shepherdia canadensis (L.) Nutt. and Sh. argentea (Pusch.) Nutt. samples (260 bp and 215 bp, respectively). The PCR products were cloned and sequenced. An analysis of the sequences revealed that intraspecific levels of NTS identity are high (approximately 95–96%) and similar in the Elaeagnus L. species. In Sh. argentea, this level was slightly lower due to the differences in the poly-T region. Moreover, the intergeneric and intervarietal NTS identity levels were studied and compared. Significant differences between species (except E. multiflora Thunb. and E. umbellata Thunb.) and genera were found. Herein, a range of the NTS features is discussed. This study is another step in the investigation of the molecular evolution of Elaeagnaceae and may be useful for the development of species-specific DNA markers in this family.


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